From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 88AEF2877C2; Fri, 17 Oct 2025 18:57:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727433; cv=none; b=Kw5okmCxV5hapk4sNGcg5xiK1dlj5h7eK1U9qWmtK9o8MiPaeGWP1ClwzYgOJrEH5mVssdZ+arxRO9VtzsGgUl5bwWgxp8XKRb5JBpK2f9Sa004CDjMsesnbpKIE2hhJEzks0NL5fxbq5LKXT/DMhq9r6xEjDJcE8nX40XboNZA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727433; c=relaxed/simple; bh=THyyyRGPe5ZmB6ckvW8A5t95FK2DRf3rJYwnYRvEiKE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=d4o6My7rFCnxt3E6O/tXcmo/vbjPvDysyCvEk+PMkJM0lFpgA9xF0c386LXTyTvy7dzc9yPOkgk7KvWyhX85wnYtT2yYbeDcApk01UXLKVLFE+DGEt6wEm2Hz2Fk7tqe834fZ4357rrcML+sUXStBS+5spY78u/RrZmtLIHwCDE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 042E71515; Fri, 17 Oct 2025 11:57:03 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0185F3F66E; Fri, 17 Oct 2025 11:57:05 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 01/29] ACPI / PPTT: Add a helper to fill a cpumask from a processor container Date: Fri, 17 Oct 2025 18:56:17 +0000 Message-Id: <20251017185645.26604-2-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The ACPI MPAM table uses the UID of a processor container specified in the PPTT to indicate the subset of CPUs and cache topology that can access each MPAM System Component (MSC). This information is not directly useful to the kernel. The equivalent cpumask is needed instead. Add a helper to find the processor container by its id, then walk the possible CPUs to fill a cpumask with the CPUs that have this processor container as a parent. CC: Dave Martin Reviewed-by: Sudeep Holla Reviewed-by: Jonathan Cameron Reviewed-by: Fenghua Yu Reviewed-by: Gavin Shan Tested-by: Fenghua Yu Signed-off-by: James Morse Tested-by: Peter Newman --- Changes since v2: * Grouped two nested if clauses differently to reduce scope of cpu_node. * Removed stale comment refering to the return value. Changes since v1: * Replaced commit message with wording from Dave. * Fixed a stray plural. * Moved further down in the file to make use of get_pptt() helper. * Added a break to exit the loop early. Changes since RFC: * Removed leaf_flag local variable from acpi_pptt_get_cpus_from_container() Changes since RFC: * Dropped has_leaf_flag dodging of acpi_pptt_leaf_node() * Added missing : in kernel-doc * Made helper return void as this never actually returns an error. --- drivers/acpi/pptt.c | 82 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 3 ++ 2 files changed, 85 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 54676e3d82dd..58cfa3916a13 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -817,3 +817,85 @@ int find_acpi_cpu_topology_hetero_id(unsigned int cpu) return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, ACPI_PPTT_ACPI_IDENTICAL); } + +/** + * acpi_pptt_get_child_cpus() - Find all the CPUs below a PPTT processor n= ode + * @table_hdr: A reference to the PPTT table. + * @parent_node: A pointer to the processor node in the @table_hdr. + * @cpus: A cpumask to fill with the CPUs below @parent_node. + * + * Walks up the PPTT from every possible CPU to find if the provided + * @parent_node is a parent of this CPU. + */ +static void acpi_pptt_get_child_cpus(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *parent_node, + cpumask_t *cpus) +{ + struct acpi_pptt_processor *cpu_node; + u32 acpi_id; + int cpu; + + cpumask_clear(cpus); + + for_each_possible_cpu(cpu) { + acpi_id =3D get_acpi_id_for_cpu(cpu); + cpu_node =3D acpi_find_processor_node(table_hdr, acpi_id); + + while (cpu_node) { + if (cpu_node =3D=3D parent_node) { + cpumask_set_cpu(cpu, cpus); + break; + } + cpu_node =3D fetch_pptt_node(table_hdr, cpu_node->parent); + } + } +} + +/** + * acpi_pptt_get_cpus_from_container() - Populate a cpumask with all CPUs = in a + * processor container + * @acpi_cpu_id: The UID of the processor container. + * @cpus: The resulting CPU mask. + * + * Find the specified Processor Container, and fill @cpus with all the cpus + * below it. + * + * Not all 'Processor' entries in the PPTT are either a CPU or a Processor + * Container, they may exist purely to describe a Private resource. CPUs + * have to be leaves, so a Processor Container is a non-leaf that has the + * 'ACPI Processor ID valid' flag set. + */ +void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus) +{ + struct acpi_table_header *table_hdr; + struct acpi_subtable_header *entry; + unsigned long table_end; + u32 proc_sz; + + cpumask_clear(cpus); + + table_hdr =3D acpi_get_pptt(); + if (!table_hdr) + return; + + table_end =3D (unsigned long)table_hdr + table_hdr->length; + entry =3D ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, + sizeof(struct acpi_table_pptt)); + proc_sz =3D sizeof(struct acpi_pptt_processor); + while ((unsigned long)entry + proc_sz <=3D table_end) { + + if (entry->type =3D=3D ACPI_PPTT_TYPE_PROCESSOR) { + struct acpi_pptt_processor *cpu_node; + + cpu_node =3D (struct acpi_pptt_processor *)entry; + if (cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID && + !acpi_pptt_leaf_node(table_hdr, cpu_node) && + cpu_node->acpi_processor_id =3D=3D acpi_cpu_id) { + acpi_pptt_get_child_cpus(table_hdr, cpu_node, cpus); + break; + } + } + entry =3D ACPI_ADD_PTR(struct acpi_subtable_header, entry, + entry->length); + } +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 5ff5d99f6ead..4752ebd48132 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1541,6 +1541,7 @@ int find_acpi_cpu_topology(unsigned int cpu, int leve= l); int find_acpi_cpu_topology_cluster(unsigned int cpu); int find_acpi_cpu_topology_package(unsigned int cpu); int find_acpi_cpu_topology_hetero_id(unsigned int cpu); +void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus); #else static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) { @@ -1562,6 +1563,8 @@ static inline int find_acpi_cpu_topology_hetero_id(un= signed int cpu) { return -EINVAL; } +static inline void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, + cpumask_t *cpus) { } #endif =20 void acpi_arch_init(void); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B535C332904; Fri, 17 Oct 2025 18:57:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727438; cv=none; b=h7Y3773UbES4Z1KDJLUKsLZyPLPWyxn2ZGEjBXfhEyGj/9fNaA3NWkDlFkvhPi7717nJ2RG/UnpTFUClAUvKLvwx140lRAqv0DPDAr1DzbpfttsjTDcYZQ8slDG98V+WaZOzbsuRve2y6gMYPdU4TR98rGbpKr5xCNhhZWMFP50= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727438; c=relaxed/simple; bh=crD3J0WbzA16/Tif8c6f6vFKLU0ZT/jo55J86+iBLD8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=EThhy3NCFoy2Y2EG48POAqSVMQ8zdHJ7psyQIrF9PMalW9e0prHdBo8A/QlJMuDLL9GBqqKTclIN3i9zJTsILfwD6WFmWl3ARy89MGvEzpkO4uL5EleRcX33Q1KcmPTOy91al64XniqZrt9/gJwiBPpoDNfzxS77FPsUqdSKiKc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3BF0A1595; Fri, 17 Oct 2025 11:57:08 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 384753F66E; Fri, 17 Oct 2025 11:57:11 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 02/29] ACPI / PPTT: Stop acpi_count_levels() expecting callers to clear levels Date: Fri, 17 Oct 2025 18:56:18 +0000 Message-Id: <20251017185645.26604-3-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In acpi_count_levels(), the initial value of *levels passed by the caller is really an implementation detail of acpi_count_levels(), so it is unreasonable to expect the callers of this function to know what to pass in for this parameter. The only sensible initial value is 0, which is what the only upstream caller (acpi_get_cache_info()) passes. Use a local variable for the starting cache level in acpi_count_levels(), and pass the result back to the caller via the function return value. Get rid of the levels parameter, which has no remaining purpose. Fix acpi_get_cache_info() to match. Suggested-by: Jonathan Cameron Signed-off-by: James Morse Reviewed-by: Lorenzo Pieralisi Reviewed-by: Jonathan Cameron Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Typo in commit message. Changes since v1: * Rewritten commit message from Dave. * Minor changes to kernel doc comment. * Keep the much loved typo. Changes since RFC: * Made acpi_count_levels() return the levels value. --- drivers/acpi/pptt.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 58cfa3916a13..63c3a344c075 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -177,14 +177,14 @@ acpi_find_cache_level(struct acpi_table_header *table= _hdr, } =20 /** - * acpi_count_levels() - Given a PPTT table, and a CPU node, count the cac= he - * levels and split cache levels (data/instruction). + * acpi_count_levels() - Given a PPTT table, and a CPU node, count the + * total number of levels and split cache levels (data/instruction). * @table_hdr: Pointer to the head of the PPTT table * @cpu_node: processor node we wish to count caches for - * @levels: Number of levels if success. * @split_levels: Number of split cache levels (data/instruction) if * success. Can by NULL. * + * Return: number of levels. * Given a processor node containing a processing unit, walk into it and c= ount * how many levels exist solely for it, and then walk up each level until = we hit * the root node (ignore the package level because it may be possible to h= ave @@ -192,14 +192,18 @@ acpi_find_cache_level(struct acpi_table_header *table= _hdr, * split cache levels (data/instruction) that exist at each level on the w= ay * up. */ -static void acpi_count_levels(struct acpi_table_header *table_hdr, - struct acpi_pptt_processor *cpu_node, - unsigned int *levels, unsigned int *split_levels) +static int acpi_count_levels(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *cpu_node, + unsigned int *split_levels) { + int starting_level =3D 0; + do { - acpi_find_cache_level(table_hdr, cpu_node, levels, split_levels, 0, 0); + acpi_find_cache_level(table_hdr, cpu_node, &starting_level, split_levels= , 0, 0); cpu_node =3D fetch_pptt_node(table_hdr, cpu_node->parent); } while (cpu_node); + + return starting_level; } =20 /** @@ -645,7 +649,7 @@ int acpi_get_cache_info(unsigned int cpu, unsigned int = *levels, if (!cpu_node) return -ENOENT; =20 - acpi_count_levels(table, cpu_node, levels, split_levels); + *levels =3D acpi_count_levels(table, cpu_node, split_levels); =20 pr_debug("Cache Setup: last_level=3D%d split_levels=3D%d\n", *levels, split_levels ? *split_levels : -1); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 003A2330317; Fri, 17 Oct 2025 18:57:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727444; cv=none; b=pibJhrhak7Dz7v1YXtD2wkNUintf1JJcFtw5ukiQhqDv4Ve7srKYYjotnK/Pgl3TFF5LFbYMyTeKZ2FT5ZT13BH25wfwepsdc6ari3YVNxBDS94Vx3lhD3lU4A+rpt0lB8WA4mpC4oeRQKFDJNhufDRvqjwWOypn+Lx97TA0TZU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727444; c=relaxed/simple; bh=M26SC7w4krmA6Hi0XupegjnBYPtOSIBkMeLgs1ckZ4g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=kabfKcm1Sfyg7nndiOi3z7YueLumvNX+jgp5gVVxBU5n02cN5rP8Zf6J7xJBlJ8XT1F46OBPSaK1JvMvczfLrJnFPH1uLaE4OMltpYK/pU8oNoiQvtU5pyZnHt55+UPWG61Cf5NoCqheb3Ky8f5pCsPflh4PF4JFE5oZk/Lh6po= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 72F581515; Fri, 17 Oct 2025 11:57:13 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6FF1D3F66E; Fri, 17 Oct 2025 11:57:16 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 03/29] ACPI / PPTT: Find cache level by cache-id Date: Fri, 17 Oct 2025 18:56:19 +0000 Message-Id: <20251017185645.26604-4-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The MPAM table identifies caches by id. The MPAM driver also wants to know the cache level to determine if the platform is of the shape that can be managed via resctrl. Cacheinfo has this information, but only for CPUs that are online. Waiting for all CPUs to come online is a problem for platforms where CPUs are brought online late by user-space. Add a helper that walks every possible cache, until it finds the one identified by cache-id, then return the level. Signed-off-by: James Morse Reviewed-by: Fenghua Yu Reviewed-by: Gavin Shan Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes sinec v2: * Search all caches, not just unified caches. This removes the need to cou= nt the caches first, but means a failure to find the table walks the table three times for different cache types. * Fixed return value of the no-acpi stub. * Punctuation typo in a comment, * Keep trying to parse the table even if a bogus CPU is encountered. * Specified CPUs share caches with other CPUs. Changes since v1: * Droppeed the cleanup based table freeing, use acpi_get_pptt() instead. * Removed a confusing comment. * Clarified the kernel doc. Changes since RFC: * acpi_count_levels() now returns a value. * Converted the table-get stuff to use Jonathan's cleanup helper. * Dropped Sudeep's Review tag due to the cleanup change. --- drivers/acpi/pptt.c | 82 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 5 +++ 2 files changed, 87 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 63c3a344c075..50c8f2a3c927 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -350,6 +350,27 @@ static struct acpi_pptt_cache *acpi_find_cache_node(st= ruct acpi_table_header *ta return found; } =20 +static struct acpi_pptt_cache * +acpi_find_any_type_cache_node(struct acpi_table_header *table_hdr, + u32 acpi_cpu_id, unsigned int level, + struct acpi_pptt_processor **node) +{ + struct acpi_pptt_cache *cache; + + cache =3D acpi_find_cache_node(table_hdr, acpi_cpu_id, CACHE_TYPE_UNIFIED, + level, node); + if (cache) + return cache; + + cache =3D acpi_find_cache_node(table_hdr, acpi_cpu_id, CACHE_TYPE_DATA, + level, node); + if (cache) + return cache; + + return acpi_find_cache_node(table_hdr, acpi_cpu_id, CACHE_TYPE_INST, + level, node); +} + /** * update_cache_properties() - Update cacheinfo for the given processor * @this_leaf: Kernel cache info structure being updated @@ -903,3 +924,64 @@ void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id= , cpumask_t *cpus) entry->length); } } + +/* + * find_acpi_cache_level_from_id() - Get the level of the specified cache + * @cache_id: The id field of the cache + * + * Determine the level relative to any CPU for the cache identified by + * cache_id. This allows the property to be found even if the CPUs are off= line. + * + * The returned level can be used to group caches that are peers. + * + * The PPTT table must be rev 3 or later. + * + * If one CPU's L2 is shared with another CPU as L3, this function will re= turn + * an unpredictable value. + * + * Return: -ENOENT if the PPTT doesn't exist, the revision isn't supported= or + * the cache cannot be found. + * Otherwise returns a value which represents the level of the specified c= ache. + */ +int find_acpi_cache_level_from_id(u32 cache_id) +{ + int level, cpu; + u32 acpi_cpu_id; + struct acpi_pptt_cache *cache; + struct acpi_table_header *table; + struct acpi_pptt_cache_v1 *cache_v1; + struct acpi_pptt_processor *cpu_node; + + table =3D acpi_get_pptt(); + if (!table) + return -ENOENT; + + if (table->revision < 3) + return -ENOENT; + + for_each_possible_cpu(cpu) { + acpi_cpu_id =3D get_acpi_id_for_cpu(cpu); + cpu_node =3D acpi_find_processor_node(table, acpi_cpu_id); + if (!cpu_node) + continue; + + /* Start at 1 for L1 */ + level =3D 1; + cache =3D acpi_find_any_type_cache_node(table, acpi_cpu_id, level, + &cpu_node); + while (cache) { + cache_v1 =3D ACPI_ADD_PTR(struct acpi_pptt_cache_v1, + cache, sizeof(*cache)); + + if (cache->flags & ACPI_PPTT_CACHE_ID_VALID && + cache_v1->cache_id =3D=3D cache_id) + return level; + + level++; + cache =3D acpi_find_any_type_cache_node(table, acpi_cpu_id, + level, &cpu_node); + } + } + + return -ENOENT; +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 4752ebd48132..be074bdfd4d1 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1542,6 +1542,7 @@ int find_acpi_cpu_topology_cluster(unsigned int cpu); int find_acpi_cpu_topology_package(unsigned int cpu); int find_acpi_cpu_topology_hetero_id(unsigned int cpu); void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus); +int find_acpi_cache_level_from_id(u32 cache_id); #else static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) { @@ -1565,6 +1566,10 @@ static inline int find_acpi_cpu_topology_hetero_id(u= nsigned int cpu) } static inline void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus) { } +static inline int find_acpi_cache_level_from_id(u32 cache_id) +{ + return -ENOENT; +} #endif =20 void acpi_arch_init(void); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 34C81330317; Fri, 17 Oct 2025 18:57:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727448; cv=none; b=ryD4YLLW5PSdkKO/qSv83CSH544hXMSLaVfqgHVfz4A/4UpPLIR907lcwBGFaFS8e1dTpt1rp4OoTyHXLnFU4e7O+bXu46yqRl6O5+Cynuf5cQrGHP/dCL4dKsiVXBvd08MWUBzlAtuN2DNbGHRohH8eAqGdxKNarwFEDgxEwY0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727448; c=relaxed/simple; bh=EdCAq6AZ+4n/hjnkjVeXL1mEx4WBLyKK+iCIn5mrQxU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fDBgzxjAaCZ4FL5KV1AVrZ1lzxgDcCJCk3WZm/dSVDEcTIg9UvqglsMDqMBM3giv4GcsZAMmzXlCGF48RUCpGIBmYYK23HDqfzXM9jVy9Vnt8Vis+ClzxWnq2jXiciVSRm6iXevCijWni4Lpm3hjaJ0o8+u3/x+d1WPbQl7xuos= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CDE541515; Fri, 17 Oct 2025 11:57:18 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A71183F66E; Fri, 17 Oct 2025 11:57:21 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Rohit Mathew Subject: [PATCH v3 04/29] ACPI / PPTT: Add a helper to fill a cpumask from a cache_id Date: Fri, 17 Oct 2025 18:56:20 +0000 Message-Id: <20251017185645.26604-5-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" MPAM identifies CPUs by the cache_id in the PPTT cache structure. The driver needs to know which CPUs are associated with the cache. The CPUs may not all be online, so cacheinfo does not have the information. Add a helper to pull this information out of the PPTT. CC: Rohit Mathew Signed-off-by: James Morse Reviewed-by: Sudeep Holla Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Removed stray cleanup useage in preference for acpi_get_pptt(). * Removed WARN_ON_ONCE() for symmetry with other helpers. * Dropped restriction on unified caches. Changes since v1: * Added punctuation to the commit message. * Removed a comment about an alternative implementaion. * Made the loop continue with a warning if a CPU is missing from the PPTT. Changes since RFC: * acpi_count_levels() now returns a value. * Converted the table-get stuff to use Jonathan's cleanup helper. * Dropped Sudeep's Review tag due to the cleanup change. --- drivers/acpi/pptt.c | 64 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 6 +++++ 2 files changed, 70 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 50c8f2a3c927..2f86f58699a6 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -985,3 +985,67 @@ int find_acpi_cache_level_from_id(u32 cache_id) =20 return -ENOENT; } + +/** + * acpi_pptt_get_cpumask_from_cache_id() - Get the cpus associated with the + * specified cache + * @cache_id: The id field of the cache + * @cpus: Where to build the cpumask + * + * Determine which CPUs are below this cache in the PPTT. This allows the = property + * to be found even if the CPUs are offline. + * + * The PPTT table must be rev 3 or later, + * + * Return: -ENOENT if the PPTT doesn't exist, or the cache cannot be found. + * Otherwise returns 0 and sets the cpus in the provided cpumask. + */ +int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus) +{ + int level, cpu; + u32 acpi_cpu_id; + struct acpi_pptt_cache *cache; + struct acpi_table_header *table; + struct acpi_pptt_cache_v1 *cache_v1; + struct acpi_pptt_processor *cpu_node; + + cpumask_clear(cpus); + + table =3D acpi_get_pptt(); + if (!table) + return -ENOENT; + + if (table->revision < 3) + return -ENOENT; + + for_each_possible_cpu(cpu) { + acpi_cpu_id =3D get_acpi_id_for_cpu(cpu); + cpu_node =3D acpi_find_processor_node(table, acpi_cpu_id); + if (!cpu_node) + continue; + + /* Start at 1 for L1 */ + level =3D 1; + cache =3D acpi_find_any_type_cache_node(table, acpi_cpu_id, level, + &cpu_node); + while (cache) { + cache_v1 =3D ACPI_ADD_PTR(struct acpi_pptt_cache_v1, + cache, sizeof(*cache)); + if (!cache) + continue; + + cache_v1 =3D ACPI_ADD_PTR(struct acpi_pptt_cache_v1, + cache, sizeof(*cache)); + + if (cache->flags & ACPI_PPTT_CACHE_ID_VALID && + cache_v1->cache_id =3D=3D cache_id) + cpumask_set_cpu(cpu, cpus); + + level++; + cache =3D acpi_find_any_type_cache_node(table, acpi_cpu_id, + level, &cpu_node); + } + } + + return 0; +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index be074bdfd4d1..a9dbacabdf89 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1543,6 +1543,7 @@ int find_acpi_cpu_topology_package(unsigned int cpu); int find_acpi_cpu_topology_hetero_id(unsigned int cpu); void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus); int find_acpi_cache_level_from_id(u32 cache_id); +int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus); #else static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) { @@ -1570,6 +1571,11 @@ static inline int find_acpi_cache_level_from_id(u32 = cache_id) { return -ENOENT; } +static inline int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, + cpumask_t *cpus) +{ + return -ENOENT; +} #endif =20 void acpi_arch_init(void); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BC86F332907; Fri, 17 Oct 2025 18:57:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727454; cv=none; b=cJ32XfurMF++AgVqPxxp4AS8C4nqhY9T1a6lIpn3Dvl+jIsfm75+uAE9zuDHvlSakk6Int9PSaSORjOpKrbKDvyye6WU39YajVfjXizS4eB41zVypy4lhFshXi3+xb0yQu4yNLpR61T6iCqlNFlQlWlIRxP4yvyoXN7DEuBK1Hs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727454; c=relaxed/simple; bh=CAI9L6eVV59ieQIxZNDJbzNb4TRQJYnXv39FR5yBpJk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=l4hUKvMPSI5DhQHn2xlCxIdydMRRBZJ3E5Aof9yBsVryzJ5SaUM1HQqsTyTrUGYI1mzQz577xgQj0pYlkLqi0mr9EwRWR7D2fZxMjBzsb/KblKTnck45suyEZA0YJy2/AbcaQ+vILVJANKCaD8Txm9SVgMaHQ/oJIdvJ/zTWGuk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 32A4A1595; Fri, 17 Oct 2025 11:57:24 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 09D5A3F66E; Fri, 17 Oct 2025 11:57:26 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 05/29] arm64: kconfig: Add Kconfig entry for MPAM Date: Fri, 17 Oct 2025 18:56:21 +0000 Message-Id: <20251017185645.26604-6-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The bulk of the MPAM driver lives outside the arch code because it largely manages MMIO devices that generate interrupts. The driver needs a Kconfig symbol to enable it. As MPAM is only found on arm64 platforms, the arm64 tree is the most natural home for the Kconfig option. This Kconfig option will later be used by the arch code to enable or disable the MPAM context-switch code, and to register properties of CPUs with the MPAM driver. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Reviewed-by: Fenghua Yu Reviewed-by: Gavin Shan Tested-by: Fenghua Yu CC: Dave Martin Tested-by: Peter Newman --- Changes since v1: * Help text rewritten by Dave. --- arch/arm64/Kconfig | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 6663ffd23f25..67015d51f7b5 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2023,6 +2023,29 @@ config ARM64_TLB_RANGE ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a range of input addresses. =20 +config ARM64_MPAM + bool "Enable support for MPAM" + help + Memory System Resource Partitioning and Monitoring (MPAM) is an + optional extension to the Arm architecture that allows each + transaction issued to the memory system to be labelled with a + Partition identifier (PARTID) and Performance Monitoring Group + identifier (PMG). + + Memory system components, such as the caches, can be configured with + policies to control how much of various physical resources (such as + memory bandwidth or cache memory) the transactions labelled with each + PARTID can consume. Depending on the capabilities of the hardware, + the PARTID and PMG can also be used as filtering criteria to measure + the memory system resource consumption of different parts of a + workload. + + Use of this extension requires CPU support, support in the + Memory System Components (MSC), and a description from firmware + of where the MSCs are in the address space. + + MPAM is exposed to user-space via the resctrl pseudo filesystem. + endmenu # "ARMv8.4 architectural features" =20 menu "ARMv8.5 architectural features" --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0D3B3332904; Fri, 17 Oct 2025 18:57:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727460; cv=none; b=EgFszRvGfhd8Jfsu+WijZaRAUWN/gYz3TXyfzRk1LnyNYDfbCcYZuqWGeG1P06Zh5PBE42qqXUHKd6MeDJYNMJS5KGXAJsBEUb5gFG7OH0Y+Entc5K5EBb5FO2fy2T1kzPFCjvI9ob8uAcnkWTytG9YuGdStYDKWGuc3RMnuSSE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727460; c=relaxed/simple; bh=yDEb16V/HblNKdG3Btn3upfzJwhA1at/LcH5bd+zWWU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LPGMndGAKj/PGmWrZlinmLuHWHcstgLV1zeSt6hCnOReUAJOUvo4+OW4nS7JenJPyKjOxm8OOWog6oUufvfmexrC6IWQDW4DHk3+WEUSgVpkv87JLuj0AcDc7ZlfRgaSsMMLmh88IBcIyjDMLxXfhC1Cm87NZUxMZarNR2yw32A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9060B1515; Fri, 17 Oct 2025 11:57:29 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 67E823F66E; Fri, 17 Oct 2025 11:57:32 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 06/29] ACPI / MPAM: Parse the MPAM table Date: Fri, 17 Oct 2025 18:56:22 +0000 Message-Id: <20251017185645.26604-7-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add code to parse the arm64 specific MPAM table, looking up the cache level from the PPTT and feeding the end result into the MPAM driver. This happens in two stages. Platform devices are created first for the MSC devices. Once the driver probes it calls acpi_mpam_parse_resources() to discover the RIS entries the MSC contains. For now the MPAM hook mpam_ris_create() is stubbed out, but will update the MPAM driver with optional discovered data about the RIS entries. CC: Carl Worth Link: https://developer.arm.com/documentation/den0065/3-0bet/?lang=3Den Reviewed-by: Lorenzo Pieralisi Tested-by: Fenghua Yu Signed-off-by: James Morse Tested-by: Peter Newman --- Changes since v2: * Expanded commit message. * Moved explicit memset() to array initialisation. * Added comments on the sizing of arrays. * Moved MSC table entry parsing to a helper to allow use of a platform-dev= ice cleanup rune, result int more returns and fewer breaks. * Changed pre-processor macros for table bits. * Discover unsupported PPI partitions purely from the table to make gicv5 easier, which also simplifies acpi_mpam_parse_irqs() * Gave interface type numbers pre-processor names. * Clarified some comments. * Fixed the WARN_ON comparison in acpi_mpam_parse_msc(). * Made buffer over-run noisier. * Print an error condition as %d not %u. * Print a debug message when bad NUMA nodes are found. Changes since v1: * Whitespace. * Gave GLOBAL_AFFINITY a pre-processor'd name. * Fixed assumption that there are zero functional dependencies. * Bounds check walking of the MSC RIS. * More bounds checking in the main table walk. * Check for nonsense numbers of function dependencies. * Smattering of pr_debug() to help folk feeding line-noise to the parser. * Changed the comment flavour on the SPDX string. * Removed additional table check. * More comment wrangling. Changes since RFC: * Used DEFINE_RES_IRQ_NAMED() and friends macros. * Additional error handling. * Check for zero sized MSC. * Allow table revisions greater than 1. (no spec for revision 0!) * Use cleanup helpers to retrieve ACPI tables, which allows some functions to be folded together. --- arch/arm64/Kconfig | 1 + drivers/acpi/arm64/Kconfig | 3 + drivers/acpi/arm64/Makefile | 1 + drivers/acpi/arm64/mpam.c | 377 ++++++++++++++++++++++++++++++++ drivers/acpi/tables.c | 2 +- include/linux/acpi.h | 12 + include/linux/arm_mpam.h | 48 ++++ include/linux/platform_device.h | 1 + 8 files changed, 444 insertions(+), 1 deletion(-) create mode 100644 drivers/acpi/arm64/mpam.c create mode 100644 include/linux/arm_mpam.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 67015d51f7b5..c5e66d5d72cd 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2025,6 +2025,7 @@ config ARM64_TLB_RANGE =20 config ARM64_MPAM bool "Enable support for MPAM" + select ACPI_MPAM if ACPI help Memory System Resource Partitioning and Monitoring (MPAM) is an optional extension to the Arm architecture that allows each diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig index b3ed6212244c..f2fd79f22e7d 100644 --- a/drivers/acpi/arm64/Kconfig +++ b/drivers/acpi/arm64/Kconfig @@ -21,3 +21,6 @@ config ACPI_AGDI =20 config ACPI_APMT bool + +config ACPI_MPAM + bool diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile index 05ecde9eaabe..9390b57cb564 100644 --- a/drivers/acpi/arm64/Makefile +++ b/drivers/acpi/arm64/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_ACPI_APMT) +=3D apmt.o obj-$(CONFIG_ACPI_FFH) +=3D ffh.o obj-$(CONFIG_ACPI_GTDT) +=3D gtdt.o obj-$(CONFIG_ACPI_IORT) +=3D iort.o +obj-$(CONFIG_ACPI_MPAM) +=3D mpam.o obj-$(CONFIG_ACPI_PROCESSOR_IDLE) +=3D cpuidle.o obj-$(CONFIG_ARM_AMBA) +=3D amba.o obj-y +=3D dma.o init.o diff --git a/drivers/acpi/arm64/mpam.c b/drivers/acpi/arm64/mpam.c new file mode 100644 index 000000000000..59712397025d --- /dev/null +++ b/drivers/acpi/arm64/mpam.c @@ -0,0 +1,377 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2025 Arm Ltd. + +/* Parse the MPAM ACPI table feeding the discovered nodes into the driver = */ + +#define pr_fmt(fmt) "ACPI MPAM: " fmt + +#include +#include +#include +#include +#include +#include + +#include + +/* + * Flags for acpi_table_mpam_msc.*_interrupt_flags. + * See 2.1.1 Interrupt Flags, Table 5, of DEN0065B_MPAM_ACPI_3.0-bet. + */ +#define ACPI_MPAM_MSC_IRQ_MODE BIT(0) +#define ACPI_MPAM_MSC_IRQ_TYPE_MASK GENMASK(2, 1) +#define ACPI_MPAM_MSC_IRQ_TYPE_WIRED 0 +#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_MASK BIT(3) +#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR 0 +#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR_CONTAINER 1 +#define ACPI_MPAM_MSC_IRQ_AFFINITY_VALID BIT(4) + +/* + * Encodings for the MSC node body interface type field. + * See 2.1 MPAM MSC node, Table 4 of DEN0065B_MPAM_ACPI_3.0-bet. + */ +#define ACPI_MPAM_MSC_IFACE_MMIO 0x00 +#define ACPI_MPAM_MSC_IFACE_PCC 0x0a + +static bool _is_ppi_partition(u32 flags) +{ + u32 aff_type, is_ppi; + bool ret; + + is_ppi =3D FIELD_GET(ACPI_MPAM_MSC_IRQ_AFFINITY_VALID, flags); + if (!is_ppi) + return false; + + aff_type =3D FIELD_GET(ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_MASK, flags); + ret =3D (aff_type =3D=3D ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR_CONTAI= NER); + if (ret) + pr_err_once("Partitioned interrupts not supported\n"); + + return ret; +} + +static bool acpi_mpam_register_irq(struct platform_device *pdev, int intid, + u32 flags, int *irq) +{ + u32 int_type; + int sense; + + if (!intid) + return false; + + if (_is_ppi_partition(flags)) + return false; + + sense =3D FIELD_GET(ACPI_MPAM_MSC_IRQ_MODE, flags); + int_type =3D FIELD_GET(ACPI_MPAM_MSC_IRQ_TYPE_MASK, flags); + if (int_type !=3D ACPI_MPAM_MSC_IRQ_TYPE_WIRED) + return false; + + *irq =3D acpi_register_gsi(&pdev->dev, intid, sense, ACPI_ACTIVE_HIGH); + if (*irq <=3D 0) { + pr_err_once("Failed to register interrupt 0x%x with ACPI\n", + intid); + return false; + } + + return true; +} + +static void acpi_mpam_parse_irqs(struct platform_device *pdev, + struct acpi_mpam_msc_node *tbl_msc, + struct resource *res, int *res_idx) +{ + u32 flags, intid; + int irq; + + intid =3D tbl_msc->overflow_interrupt; + flags =3D tbl_msc->overflow_interrupt_flags; + if (acpi_mpam_register_irq(pdev, intid, flags, &irq)) + res[(*res_idx)++] =3D DEFINE_RES_IRQ_NAMED(irq, "overflow"); + + intid =3D tbl_msc->error_interrupt; + flags =3D tbl_msc->error_interrupt_flags; + if (acpi_mpam_register_irq(pdev, intid, flags, &irq)) + res[(*res_idx)++] =3D DEFINE_RES_IRQ_NAMED(irq, "error"); +} + +static int acpi_mpam_parse_resource(struct mpam_msc *msc, + struct acpi_mpam_resource_node *res) +{ + int level, nid; + u32 cache_id; + + switch (res->locator_type) { + case ACPI_MPAM_LOCATION_TYPE_PROCESSOR_CACHE: + cache_id =3D res->locator.cache_locator.cache_reference; + level =3D find_acpi_cache_level_from_id(cache_id); + if (level <=3D 0) { + pr_err_once("Bad level (%d) for cache with id %u\n", level, cache_id); + return -EINVAL; + } + return mpam_ris_create(msc, res->ris_index, MPAM_CLASS_CACHE, + level, cache_id); + case ACPI_MPAM_LOCATION_TYPE_MEMORY: + nid =3D pxm_to_node(res->locator.memory_locator.proximity_domain); + if (nid =3D=3D NUMA_NO_NODE) { + pr_debug("Bad proxmity domain %lld, using node 0 instead\n", + res->locator.memory_locator.proximity_domain); + nid =3D 0; + } + return mpam_ris_create(msc, res->ris_index, MPAM_CLASS_MEMORY, + 255, nid); + default: + /* These get discovered later and are treated as unknown */ + return 0; + } +} + +int acpi_mpam_parse_resources(struct mpam_msc *msc, + struct acpi_mpam_msc_node *tbl_msc) +{ + int i, err; + char *ptr, *table_end; + struct acpi_mpam_resource_node *resource; + + ptr =3D (char *)(tbl_msc + 1); + table_end =3D ptr + tbl_msc->length; + for (i =3D 0; i < tbl_msc->num_resource_nodes; i++) { + u64 max_deps, remaining_table; + + if (ptr + sizeof(*resource) > table_end) + return -EINVAL; + + resource =3D (struct acpi_mpam_resource_node *)ptr; + + remaining_table =3D table_end - ptr; + max_deps =3D remaining_table / sizeof(struct acpi_mpam_func_deps); + if (resource->num_functional_deps > max_deps) { + pr_debug("MSC has impossible number of functional dependencies\n"); + return -EINVAL; + } + + err =3D acpi_mpam_parse_resource(msc, resource); + if (err) + return err; + + ptr +=3D sizeof(*resource); + ptr +=3D resource->num_functional_deps * sizeof(struct acpi_mpam_func_de= ps); + } + + return 0; +} + +static bool __init parse_msc_pm_link(struct acpi_mpam_msc_node *tbl_msc, + struct platform_device *pdev, + u32 *acpi_id) +{ + char hid[sizeof(tbl_msc->hardware_id_linked_device) + 1] =3D { 0 }; + bool acpi_id_valid =3D false; + struct acpi_device *buddy; + char uid[11]; + int err; + + memcpy(hid, &tbl_msc->hardware_id_linked_device, + sizeof(tbl_msc->hardware_id_linked_device)); + + if (!strcmp(hid, ACPI_PROCESSOR_CONTAINER_HID)) { + *acpi_id =3D tbl_msc->instance_id_linked_device; + acpi_id_valid =3D true; + } + + err =3D snprintf(uid, sizeof(uid), "%u", + tbl_msc->instance_id_linked_device); + if (err >=3D sizeof(uid)) { + pr_debug("Failed to convert uid of device for power management."); + return acpi_id_valid; + } + + buddy =3D acpi_dev_get_first_match_dev(hid, uid, -1); + if (buddy) + device_link_add(&pdev->dev, &buddy->dev, DL_FLAG_STATELESS); + + return acpi_id_valid; +} + +static int decode_interface_type(struct acpi_mpam_msc_node *tbl_msc, + enum mpam_msc_iface *iface) +{ + switch (tbl_msc->interface_type) { + case ACPI_MPAM_MSC_IFACE_MMIO: + *iface =3D MPAM_IFACE_MMIO; + return 0; + case ACPI_MPAM_MSC_IFACE_PCC: + *iface =3D MPAM_IFACE_PCC; + return 0; + default: + return -EINVAL; + } +} + +static struct platform_device * __init acpi_mpam_parse_msc(struct acpi_mpa= m_msc_node *tbl_msc) +{ + struct platform_device *pdev __free(platform_device_put) =3D platform_dev= ice_alloc("mpam_msc", tbl_msc->identifier); + int next_res =3D 0, next_prop =3D 0, err; + /* pcc, nrdy, affinity and a sentinel */ + struct property_entry props[4] =3D { 0 }; + /* mmio, 2xirq, no sentinel. */ + struct resource res[3] =3D { 0 }; + struct acpi_device *companion; + enum mpam_msc_iface iface; + char uid[16]; + u32 acpi_id; + + if (!pdev) + return ERR_PTR(-ENOMEM); + + /* Some power management is described in the namespace: */ + err =3D snprintf(uid, sizeof(uid), "%u", tbl_msc->identifier); + if (err > 0 && err < sizeof(uid)) { + companion =3D acpi_dev_get_first_match_dev("ARMHAA5C", uid, -1); + if (companion) + ACPI_COMPANION_SET(&pdev->dev, companion); + else + pr_debug("MSC.%u: missing namespace entry\n", + tbl_msc->identifier); + } + + if (decode_interface_type(tbl_msc, &iface)) { + pr_debug("MSC.%u: unknown interface type\n", tbl_msc->identifier); + return ERR_PTR(-EINVAL); + } + + if (iface =3D=3D MPAM_IFACE_MMIO) + res[next_res++] =3D DEFINE_RES_MEM_NAMED(tbl_msc->base_address, + tbl_msc->mmio_size, + "MPAM:MSC"); + else if (iface =3D=3D MPAM_IFACE_PCC) + props[next_prop++] =3D PROPERTY_ENTRY_U32("pcc-channel", + tbl_msc->base_address); + + acpi_mpam_parse_irqs(pdev, tbl_msc, res, &next_res); + + WARN_ON_ONCE(next_res > ARRAY_SIZE(res)); + err =3D platform_device_add_resources(pdev, res, next_res); + if (err) + return ERR_PTR(err); + + props[next_prop++] =3D PROPERTY_ENTRY_U32("arm,not-ready-us", + tbl_msc->max_nrdy_usec); + + /* + * The MSC's CPU affinity is described via its linked power + * management device, but only if it points at a Processor or + * Processor Container. + */ + if (parse_msc_pm_link(tbl_msc, pdev, &acpi_id)) + props[next_prop++] =3D PROPERTY_ENTRY_U32("cpu_affinity", acpi_id); + + WARN_ON_ONCE(next_prop > ARRAY_SIZE(props)); + err =3D device_create_managed_software_node(&pdev->dev, props, NULL); + if (err) + return ERR_PTR(err); + + /* + * Stash the table entry for acpi_mpam_parse_resources() to discover + * what this MSC controls. + */ + err =3D platform_device_add_data(pdev, tbl_msc, tbl_msc->length); + if (err) + return ERR_PTR(err); + + err =3D platform_device_add(pdev); + if (err) + return ERR_PTR(err); + + return_ptr(pdev); +} + +static int __init acpi_mpam_parse(void) +{ + struct acpi_table_header *table __free(acpi_table) =3D acpi_get_table_ret= (ACPI_SIG_MPAM, 0); + char *table_end, *table_offset =3D (char *)(table + 1); + struct acpi_mpam_msc_node *tbl_msc; + struct platform_device *pdev; + + if (acpi_disabled || !system_supports_mpam() || IS_ERR(table)) + return 0; + + if (table->revision < 1) + return 0; + + table_end =3D (char *)table + table->length; + + while (table_offset < table_end) { + tbl_msc =3D (struct acpi_mpam_msc_node *)table_offset; + table_offset +=3D tbl_msc->length; + + if (table_offset > table_end) { + pr_err("MSC entry overlaps end of ACPI table\n"); + return -EINVAL; + } + + /* + * If any of the reserved fields are set, make no attempt to + * parse the MSC structure. This MSC will still be counted by + * acpi_mpam_count_msc(), meaning the MPAM driver can't probe + * against all MSC, and will never be enabled. There is no way + * to enable it safely, because we cannot determine safe + * system-wide partid and pmg ranges in this situation. + */ + if (tbl_msc->reserved || tbl_msc->reserved1 || tbl_msc->reserved2) { + pr_err_once("Unrecognised MSC, MPAM not usable\n"); + pr_debug("MSC.%u: reserved field set\n", tbl_msc->identifier); + continue; + } + + if (!tbl_msc->mmio_size) { + pr_debug("MSC.%u: marked as disabled\n", tbl_msc->identifier); + continue; + } + + pdev =3D acpi_mpam_parse_msc(tbl_msc); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + } + + return 0; +} + +int acpi_mpam_count_msc(void) +{ + struct acpi_table_header *table __free(acpi_table) =3D acpi_get_table_ret= (ACPI_SIG_MPAM, 0); + char *table_end, *table_offset =3D (char *)(table + 1); + struct acpi_mpam_msc_node *tbl_msc; + int count =3D 0; + + if (IS_ERR(table)) + return 0; + + if (table->revision < 1) + return 0; + + table_end =3D (char *)table + table->length; + + while (table_offset < table_end) { + tbl_msc =3D (struct acpi_mpam_msc_node *)table_offset; + if (!tbl_msc->mmio_size) + continue; + + if (tbl_msc->length < sizeof(*tbl_msc)) + return -EINVAL; + if (tbl_msc->length > table_end - table_offset) + return -EINVAL; + table_offset +=3D tbl_msc->length; + + count++; + } + + return count; +} + +/* + * Call after ACPI devices have been created, which happens behind acpi_sc= an_init() + * called from subsys_initcall(). PCC requires the mailbox driver, which is + * initialised from postcore_initcall(). + */ +subsys_initcall_sync(acpi_mpam_parse); diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index 57fc8bc56166..4286e4af1092 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -408,7 +408,7 @@ static const char table_sigs[][ACPI_NAMESEG_SIZE] __non= string_array __initconst ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT, ACPI_SIG_NHLT, ACPI_SIG_AEST, ACPI_SIG_CEDT, ACPI_SIG_AGDI, - ACPI_SIG_NBFT, ACPI_SIG_SWFT}; + ACPI_SIG_NBFT, ACPI_SIG_SWFT, ACPI_SIG_MPAM}; =20 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header) =20 diff --git a/include/linux/acpi.h b/include/linux/acpi.h index a9dbacabdf89..9d66421f68ff 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -8,6 +8,7 @@ #ifndef _LINUX_ACPI_H #define _LINUX_ACPI_H =20 +#include #include #include /* for struct resource */ #include @@ -221,6 +222,17 @@ void acpi_reserve_initial_tables (void); void acpi_table_init_complete (void); int acpi_table_init (void); =20 +static inline struct acpi_table_header *acpi_get_table_ret(char *signature= , u32 instance) +{ + struct acpi_table_header *table; + int status =3D acpi_get_table(signature, instance, &table); + + if (ACPI_FAILURE(status)) + return ERR_PTR(-ENOENT); + return table; +} +DEFINE_FREE(acpi_table, struct acpi_table_header *, if (!IS_ERR(_T)) acpi_= put_table(_T)) + int acpi_table_parse(char *id, acpi_tbl_table_handler handler); int __init_or_acpilib acpi_table_parse_entries(char *id, unsigned long table_size, int entry_id, diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h new file mode 100644 index 000000000000..3d6c39c667c3 --- /dev/null +++ b/include/linux/arm_mpam.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2025 Arm Ltd. */ + +#ifndef __LINUX_ARM_MPAM_H +#define __LINUX_ARM_MPAM_H + +#include +#include + +#define GLOBAL_AFFINITY ~0 + +struct mpam_msc; + +enum mpam_msc_iface { + MPAM_IFACE_MMIO, /* a real MPAM MSC */ + MPAM_IFACE_PCC, /* a fake MPAM MSC */ +}; + +enum mpam_class_types { + MPAM_CLASS_CACHE, /* Well known caches, e.g. L2 */ + MPAM_CLASS_MEMORY, /* Main memory */ + MPAM_CLASS_UNKNOWN, /* Everything else, e.g. SMMU */ +}; + +#ifdef CONFIG_ACPI_MPAM +/* Parse the ACPI description of resources entries for this MSC. */ +int acpi_mpam_parse_resources(struct mpam_msc *msc, + struct acpi_mpam_msc_node *tbl_msc); + +int acpi_mpam_count_msc(void); +#else +static inline int acpi_mpam_parse_resources(struct mpam_msc *msc, + struct acpi_mpam_msc_node *tbl_msc) +{ + return -EINVAL; +} + +static inline int acpi_mpam_count_msc(void) { return -EINVAL; } +#endif + +static inline int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, + enum mpam_class_types type, u8 class_id, + int component_id) +{ + return -EINVAL; +} + +#endif /* __LINUX_ARM_MPAM_H */ diff --git a/include/linux/platform_device.h b/include/linux/platform_devic= e.h index 074754c23d33..23a30ada2d4c 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -232,6 +232,7 @@ extern int platform_device_add_data(struct platform_dev= ice *pdev, extern int platform_device_add(struct platform_device *pdev); extern void platform_device_del(struct platform_device *pdev); extern void platform_device_put(struct platform_device *pdev); +DEFINE_FREE(platform_device_put, struct platform_device *, if (_T) platfor= m_device_put(_T)) =20 struct platform_driver { int (*probe)(struct platform_device *); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4CE0A335083; Fri, 17 Oct 2025 18:57:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727465; cv=none; b=HcDE2rl1dhy3BXaKHGRAR0hoEuG9ErIhMvjSEKRG1AFK9o2HeOJlsIxTZqBtQTE8gNdljBHii8oYi601Prf++PBqZpT6n0whD7SkrRSDfMyazWHJl+iOyI0Gmop2U72O4/g8OcE9Xn+aFvOLI/vOLq/elzcE/D6mswl94on0UOY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727465; c=relaxed/simple; bh=wU96tf+v36vtJybg9EohFQfXi6kEb5fH/k6n12cxYKg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Nql/v3PZ5foMJdIsZOS8MQY2rwCWEDjVlg5mdL8eIM/oPoT5a46MS+wzraBLAgefnU/CvCT4LXhMtso5TtcNzI9mLuL3nCiNxplZaqDMbbHJfHDHMm6IMmWB18gemF6S3zu/CqDFaij3AuAcrJ9s5kldcgM49nkzRQWchO6Ea6c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C3D911515; Fri, 17 Oct 2025 11:57:34 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C137C3F66E; Fri, 17 Oct 2025 11:57:37 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 07/29] arm_mpam: Add probe/remove for mpam msc driver and kbuild boiler plate Date: Fri, 17 Oct 2025 18:56:23 +0000 Message-Id: <20251017185645.26604-8-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Probing MPAM is convoluted. MSCs that are integrated with a CPU may only be accessible from those CPUs, and they may not be online. Touching the hardware early is pointless as MPAM can't be used until the system-wide common values for num_partid and num_pmg have been discovered. Start with driver probe/remove and mapping the MSC. CC: Carl Worth Tested-by: Fenghua Yu Signed-off-by: James Morse Tested-by: Peter Newman Tested-by: Tushar Dave --- Changes since v2: * Comment in Kconfig about why EXPERT. * Dropped duplicate depends. * Fixed duplicate return statement. * Restructured driver probe to have a do_ function to allow breaks to be return instead... * Removed resctrl.h include, added spinlock.h * Removed stray DT function prototype * Removed stray PCC variables in struct mpam_msc. * Used ccflags not cflags for debug define. * Moved srcu header include to internal.h * Moved mpam_msc_destroy() into this patch. Changes since v1: * Avoid selecting driver on other architectrues. * Removed PCC support stub. * Use for_each_available_child_of_node_scoped() and of_property_read_reg() * Clarified a comment. * Stopped using mpam_num_msc as an id,a and made it atomic. * Size of -1 returned from cache_of_calculate_id() * Renamed some struct members. * Made a bunch of pr_err() dev_err_ocne(). * Used more cleanup magic. * Inlined a print message. * Fixed error propagation from mpam_dt_parse_resources(). * Moved cache accessibility checks earlier. * Change cleanup macro to use IS_ERR_OR_NULL(). Changes since RFC: * Check for status=3Dbroken DT devices. * Moved all the files around. * Made Kconfig symbols depend on EXPERT --- arch/arm64/Kconfig | 1 + drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/acpi/arm64/mpam.c | 7 ++ drivers/resctrl/Kconfig | 13 +++ drivers/resctrl/Makefile | 4 + drivers/resctrl/mpam_devices.c | 190 ++++++++++++++++++++++++++++++++ drivers/resctrl/mpam_internal.h | 52 +++++++++ include/linux/acpi.h | 2 +- 9 files changed, 271 insertions(+), 1 deletion(-) create mode 100644 drivers/resctrl/Kconfig create mode 100644 drivers/resctrl/Makefile create mode 100644 drivers/resctrl/mpam_devices.c create mode 100644 drivers/resctrl/mpam_internal.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index c5e66d5d72cd..004d58cfbff8 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2025,6 +2025,7 @@ config ARM64_TLB_RANGE =20 config ARM64_MPAM bool "Enable support for MPAM" + select ARM64_MPAM_DRIVER if EXPERT # does nothing yet select ACPI_MPAM if ACPI help Memory System Resource Partitioning and Monitoring (MPAM) is an diff --git a/drivers/Kconfig b/drivers/Kconfig index 4915a63866b0..3054b50a2f4c 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -251,4 +251,6 @@ source "drivers/hte/Kconfig" =20 source "drivers/cdx/Kconfig" =20 +source "drivers/resctrl/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index 8e1ffa4358d5..20eb17596b89 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -194,6 +194,7 @@ obj-$(CONFIG_HTE) +=3D hte/ obj-$(CONFIG_DRM_ACCEL) +=3D accel/ obj-$(CONFIG_CDX_BUS) +=3D cdx/ obj-$(CONFIG_DPLL) +=3D dpll/ +obj-y +=3D resctrl/ =20 obj-$(CONFIG_DIBS) +=3D dibs/ obj-$(CONFIG_S390) +=3D s390/ diff --git a/drivers/acpi/arm64/mpam.c b/drivers/acpi/arm64/mpam.c index 59712397025d..51c6f5fd4a5e 100644 --- a/drivers/acpi/arm64/mpam.c +++ b/drivers/acpi/arm64/mpam.c @@ -337,6 +337,13 @@ static int __init acpi_mpam_parse(void) return 0; } =20 +/** + * acpi_mpam_count_msc() - Count the number of MSC described by firmware. + * + * Returns the number of of MSC, or zero for an error. + * + * This can be called before or in parallel with acpi_mpam_parse(). + */ int acpi_mpam_count_msc(void) { struct acpi_table_header *table __free(acpi_table) =3D acpi_get_table_ret= (ACPI_SIG_MPAM, 0); diff --git a/drivers/resctrl/Kconfig b/drivers/resctrl/Kconfig new file mode 100644 index 000000000000..58c83b5c8bfd --- /dev/null +++ b/drivers/resctrl/Kconfig @@ -0,0 +1,13 @@ +menuconfig ARM64_MPAM_DRIVER + bool "MPAM driver" + depends on ARM64 && ARM64_MPAM && EXPERT + help + MPAM driver for System IP, e,g. caches and memory controllers. + +if ARM64_MPAM_DRIVER +config ARM64_MPAM_DRIVER_DEBUG + bool "Enable debug messages from the MPAM driver" + help + Say yes here to enable debug messages from the MPAM driver. + +endif diff --git a/drivers/resctrl/Makefile b/drivers/resctrl/Makefile new file mode 100644 index 000000000000..898199dcf80d --- /dev/null +++ b/drivers/resctrl/Makefile @@ -0,0 +1,4 @@ +obj-$(CONFIG_ARM64_MPAM_DRIVER) +=3D mpam.o +mpam-y +=3D mpam_devices.o + +ccflags-$(CONFIG_ARM64_MPAM_DRIVER_DEBUG) +=3D -DDEBUG diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c new file mode 100644 index 000000000000..d18eeec95f79 --- /dev/null +++ b/drivers/resctrl/mpam_devices.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2025 Arm Ltd. + +#define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "mpam_internal.h" + +/* + * mpam_list_lock protects the SRCU lists when writing. Once the + * mpam_enabled key is enabled these lists are read-only, + * unless the error interrupt disables the driver. + */ +static DEFINE_MUTEX(mpam_list_lock); +static LIST_HEAD(mpam_all_msc); + +static struct srcu_struct mpam_srcu; + +/* + * Number of MSCs that have been probed. Once all MSC have been probed MPAM + * can be enabled. + */ +static atomic_t mpam_num_msc; + +/* + * An MSC can control traffic from a set of CPUs, but may only be accessib= le + * from a (hopefully wider) set of CPUs. The common reason for this is pow= er + * management. If all the CPUs in a cluster are in PSCI:CPU_SUSPEND, the + * corresponding cache may also be powered off. By making accesses from + * one of those CPUs, we ensure this isn't the case. + */ +static int update_msc_accessibility(struct mpam_msc *msc) +{ + u32 affinity_id; + int err; + + err =3D device_property_read_u32(&msc->pdev->dev, "cpu_affinity", + &affinity_id); + if (err) + cpumask_copy(&msc->accessibility, cpu_possible_mask); + else + acpi_pptt_get_cpus_from_container(affinity_id, + &msc->accessibility); + return err; +} + +static int fw_num_msc; + +static void mpam_msc_destroy(struct mpam_msc *msc) +{ + struct platform_device *pdev =3D msc->pdev; + + lockdep_assert_held(&mpam_list_lock); + + list_del_rcu(&msc->all_msc_list); + platform_set_drvdata(pdev, NULL); +} + +static void mpam_msc_drv_remove(struct platform_device *pdev) +{ + struct mpam_msc *msc =3D platform_get_drvdata(pdev); + + if (!msc) + return; + + mutex_lock(&mpam_list_lock); + mpam_msc_destroy(msc); + mutex_unlock(&mpam_list_lock); + + synchronize_srcu(&mpam_srcu); +} + +static struct mpam_msc *do_mpam_msc_drv_probe(struct platform_device *pdev) +{ + int err; + u32 tmp; + struct mpam_msc *msc; + struct resource *msc_res; + struct device *dev =3D &pdev->dev; + + lockdep_assert_held(&mpam_list_lock); + + msc =3D devm_kzalloc(&pdev->dev, sizeof(*msc), GFP_KERNEL); + if (!msc) + return ERR_PTR(-ENOMEM); + + mutex_init(&msc->probe_lock); + mutex_init(&msc->part_sel_lock); + msc->id =3D pdev->id; + msc->pdev =3D pdev; + INIT_LIST_HEAD_RCU(&msc->all_msc_list); + INIT_LIST_HEAD_RCU(&msc->ris); + + err =3D update_msc_accessibility(msc); + if (err) + return ERR_PTR(err); + if (cpumask_empty(&msc->accessibility)) { + dev_err_once(dev, "MSC is not accessible from any CPU!"); + return ERR_PTR(-EINVAL); + } + + if (device_property_read_u32(&pdev->dev, "pcc-channel", &tmp)) + msc->iface =3D MPAM_IFACE_MMIO; + else + msc->iface =3D MPAM_IFACE_PCC; + + if (msc->iface =3D=3D MPAM_IFACE_MMIO) { + void __iomem *io; + + io =3D devm_platform_get_and_ioremap_resource(pdev, 0, + &msc_res); + if (IS_ERR(io)) { + dev_err_once(dev, "Failed to map MSC base address\n"); + return (void *)io; + } + msc->mapped_hwpage_sz =3D msc_res->end - msc_res->start; + msc->mapped_hwpage =3D io; + } + + list_add_rcu(&msc->all_msc_list, &mpam_all_msc); + platform_set_drvdata(pdev, msc); + + return msc; +} + +static int mpam_msc_drv_probe(struct platform_device *pdev) +{ + int err; + struct mpam_msc *msc =3D NULL; + void *plat_data =3D pdev->dev.platform_data; + + mutex_lock(&mpam_list_lock); + msc =3D do_mpam_msc_drv_probe(pdev); + mutex_unlock(&mpam_list_lock); + if (!IS_ERR(msc)) { + /* Create RIS entries described by firmware */ + err =3D acpi_mpam_parse_resources(msc, plat_data); + if (err) + mpam_msc_drv_remove(pdev); + } else { + err =3D PTR_ERR(msc); + } + + if (!err && atomic_add_return(1, &mpam_num_msc) =3D=3D fw_num_msc) + pr_info("Discovered all MSC\n"); + + return err; +} + +static struct platform_driver mpam_msc_driver =3D { + .driver =3D { + .name =3D "mpam_msc", + }, + .probe =3D mpam_msc_drv_probe, + .remove =3D mpam_msc_drv_remove, +}; + +static int __init mpam_msc_driver_init(void) +{ + if (!system_supports_mpam()) + return -EOPNOTSUPP; + + init_srcu_struct(&mpam_srcu); + + fw_num_msc =3D acpi_mpam_count_msc(); + + if (fw_num_msc <=3D 0) { + pr_err("No MSC devices found in firmware\n"); + return -EINVAL; + } + + return platform_driver_register(&mpam_msc_driver); +} +subsys_initcall(mpam_msc_driver_init); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h new file mode 100644 index 000000000000..6ac75f3613c3 --- /dev/null +++ b/drivers/resctrl/mpam_internal.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +// Copyright (C) 2025 Arm Ltd. + +#ifndef MPAM_INTERNAL_H +#define MPAM_INTERNAL_H + +#include +#include +#include +#include +#include +#include +#include +#include + +struct platform_device; + +struct mpam_msc { + /* member of mpam_all_msc */ + struct list_head all_msc_list; + + int id; + struct platform_device *pdev; + + /* Not modified after mpam_is_enabled() becomes true */ + enum mpam_msc_iface iface; + u32 nrdy_usec; + cpumask_t accessibility; + + /* + * probe_lock is only taken during discovery. After discovery these + * properties become read-only and the lists are protected by SRCU. + */ + struct mutex probe_lock; + unsigned long ris_idxs; + u32 ris_max; + + /* mpam_msc_ris of this component */ + struct list_head ris; + + /* + * part_sel_lock protects access to the MSC hardware registers that are + * affected by MPAMCFG_PART_SEL. (including the ID registers that vary + * by RIS). + * If needed, take msc->probe_lock first. + */ + struct mutex part_sel_lock; + + void __iomem *mapped_hwpage; + size_t mapped_hwpage_sz; +}; +#endif /* MPAM_INTERNAL_H */ diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 9d66421f68ff..70f075b397ce 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -231,7 +231,7 @@ static inline struct acpi_table_header *acpi_get_table_= ret(char *signature, u32 return ERR_PTR(-ENOENT); return table; } -DEFINE_FREE(acpi_table, struct acpi_table_header *, if (!IS_ERR(_T)) acpi_= put_table(_T)) +DEFINE_FREE(acpi_table, struct acpi_table_header *, if (!IS_ERR_OR_NULL(_T= )) acpi_put_table(_T)) =20 int acpi_table_parse(char *id, acpi_tbl_table_handler handler); int __init_or_acpilib acpi_table_parse_entries(char *id, --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CEB4D336ECD; Fri, 17 Oct 2025 18:57:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727471; cv=none; b=erAkfUovICT1nvv6APq7wir6VqgDhMC00+lAtZhvpvzcCAHTnVe2RZc373GsdzuwNrfov6/CUdHD16EZm5qaYyAeDOtJX8K8Et7uYDSbokag5JrBYbdMLN/XHo4w+iG8LsAm/9IjWWD0sqcuwgvgrBj3j7sG8sZ92JhQbfWTojE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727471; c=relaxed/simple; bh=JghUqAZ6Z/jvpFGnOvt0Z8Y7lHEhHKghp/kCXrTyUys=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=M6LVeeVqCXYIB/Xibf6kokf18X5ZBn8LOUElaIghqjxJ8KMGtqbWhTIDf9xVSUtkLoNc0pqKLpkR/W6u1y1aZ5zrWR9NeLAXf5LBl9mCiHXbe61Av7CZu2B2iberqQRbHUgRkojBRvyfTh/A/kqEtYy9pn+H+27ZH5NMdp/9eJ0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 47E8C1515; Fri, 17 Oct 2025 11:57:40 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 02BA53F66E; Fri, 17 Oct 2025 11:57:42 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 08/29] arm_mpam: Add the class and component structures for firmware described ris Date: Fri, 17 Oct 2025 18:56:24 +0000 Message-Id: <20251017185645.26604-9-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" An MSC is a container of resources, each identified by their RIS index. Some RIS are described by firmware to provide their position in the system. Others are discovered when the driver probes the hardware. To configure a resource it needs to be found by its class, e.g. 'L2'. There are two kinds of grouping, a class is a set of components, which are visible to user-space as there are likely to be multiple instances of the L2 cache. (e.g. one per cluster or package) Add support for creating and destroying structures to allow a hierarchy of resources to be created. CC: Ben Horgan Tested-by: Fenghua Yu Signed-off-by: James Morse Tested-by: Peter Newman --- Changes since v2: * Renamed _get functions _find to avoid folk looking for _put. * Made init_garbage a static-inline. * Moved garbage pdev assignment closer to allocation to make that pattern clearer. * Return found MSC when 'finding' as there is no longer a lock to unlock. * Added initialisation of ris->msc_list. * Use dev_warn_once() in preference to printing the device name. Changes since v1: * Fixed a comp/vmsc typo. * Removed duplicate description from the commit message. * Moved parenthesis in the add_to_garbage() macro. * Check for out of range ris_idx when creating ris. * Removed GFP as probe_lock is no longer a spin lock. * Removed alloc flag as ended up searching the lists itself. * Added a comment about affinity masks not overlapping. Changes since RFC: * removed a pr_err() debug message that crept in. --- drivers/resctrl/mpam_devices.c | 390 +++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 93 ++++++++ include/linux/arm_mpam.h | 8 +- 3 files changed, 483 insertions(+), 8 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index d18eeec95f79..8685e50f08c6 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -30,7 +30,7 @@ static DEFINE_MUTEX(mpam_list_lock); static LIST_HEAD(mpam_all_msc); =20 -static struct srcu_struct mpam_srcu; +struct srcu_struct mpam_srcu; =20 /* * Number of MSCs that have been probed. Once all MSC have been probed MPAM @@ -38,6 +38,379 @@ static struct srcu_struct mpam_srcu; */ static atomic_t mpam_num_msc; =20 +/* + * An MSC is a physical container for controls and monitors, each identifi= ed by + * their RIS index. These share a base-address, interrupts and some MMIO + * registers. A vMSC is a virtual container for RIS in an MSC that control= or + * monitor the same thing. Members of a vMSC are all RIS in the same MSC, = but + * not all RIS in an MSC share a vMSC. + * Components are a group of vMSC that control or monitor the same thing b= ut + * are from different MSC, so have different base-address, interrupts etc. + * Classes are the set components of the same type. + * + * The features of a vMSC is the union of the RIS it contains. + * The features of a Class and Component are the common subset of the vMSC + * they contain. + * + * e.g. The system cache may have bandwidth controls on multiple interface= s, + * for regulating traffic from devices independently of traffic from CPUs. + * If these are two RIS in one MSC, they will be treated as controlling + * different things, and will not share a vMSC/component/class. + * + * e.g. The L2 may have one MSC and two RIS, one for cache-controls another + * for bandwidth. These two RIS are members of the same vMSC. + * + * e.g. The set of RIS that make up the L2 are grouped as a component. The= se + * are sometimes termed slices. They should be configured the same, as if = there + * were only one. + * + * e.g. The SoC probably has more than one L2, each attached to a distinct= set + * of CPUs. All the L2 components are grouped as a class. + * + * When creating an MSC, struct mpam_msc is added to the all mpam_all_msc = list, + * then linked via struct mpam_ris to a vmsc, component and class. + * The same MSC may exist under different class->component->vmsc paths, bu= t the + * RIS index will be unique. + */ +LIST_HEAD(mpam_classes); + +/* List of all objects that can be free()d after synchronise_srcu() */ +static LLIST_HEAD(mpam_garbage); + +static inline void init_garbage(struct mpam_garbage *garbage) +{ + init_llist_node(&garbage->llist); +} + +static struct mpam_vmsc * +mpam_vmsc_alloc(struct mpam_component *comp, struct mpam_msc *msc) +{ + struct mpam_vmsc *vmsc; + + lockdep_assert_held(&mpam_list_lock); + + vmsc =3D kzalloc(sizeof(*vmsc), GFP_KERNEL); + if (!vmsc) + return ERR_PTR(-ENOMEM); + init_garbage(&vmsc->garbage); + + INIT_LIST_HEAD_RCU(&vmsc->ris); + INIT_LIST_HEAD_RCU(&vmsc->comp_list); + vmsc->comp =3D comp; + vmsc->msc =3D msc; + + list_add_rcu(&vmsc->comp_list, &comp->vmsc); + + return vmsc; +} + +static struct mpam_vmsc *mpam_vmsc_find(struct mpam_component *comp, + struct mpam_msc *msc) +{ + struct mpam_vmsc *vmsc; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + if (vmsc->msc->id =3D=3D msc->id) + return vmsc; + } + + return mpam_vmsc_alloc(comp, msc); +} + +static struct mpam_component * +mpam_component_alloc(struct mpam_class *class, int id) +{ + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + comp =3D kzalloc(sizeof(*comp), GFP_KERNEL); + if (!comp) + return ERR_PTR(-ENOMEM); + init_garbage(&comp->garbage); + + comp->comp_id =3D id; + INIT_LIST_HEAD_RCU(&comp->vmsc); + /* affinity is updated when ris are added */ + INIT_LIST_HEAD_RCU(&comp->class_list); + comp->class =3D class; + + list_add_rcu(&comp->class_list, &class->components); + + return comp; +} + +static struct mpam_component * +mpam_component_find(struct mpam_class *class, int id) +{ + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(comp, &class->components, class_list) { + if (comp->comp_id =3D=3D id) + return comp; + } + + return mpam_component_alloc(class, id); +} + +static struct mpam_class * +mpam_class_alloc(u8 level_idx, enum mpam_class_types type) +{ + struct mpam_class *class; + + lockdep_assert_held(&mpam_list_lock); + + class =3D kzalloc(sizeof(*class), GFP_KERNEL); + if (!class) + return ERR_PTR(-ENOMEM); + init_garbage(&class->garbage); + + INIT_LIST_HEAD_RCU(&class->components); + /* affinity is updated when ris are added */ + class->level =3D level_idx; + class->type =3D type; + INIT_LIST_HEAD_RCU(&class->classes_list); + + list_add_rcu(&class->classes_list, &mpam_classes); + + return class; +} + +static struct mpam_class * +mpam_class_find(u8 level_idx, enum mpam_class_types type) +{ + struct mpam_class *class; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(class, &mpam_classes, classes_list) { + if (class->type =3D=3D type && class->level =3D=3D level_idx) + return class; + } + + return mpam_class_alloc(level_idx, type); +} + +#define add_to_garbage(x) \ +do { \ + __typeof__(x) _x =3D (x); \ + _x->garbage.to_free =3D _x; \ + llist_add(&_x->garbage.llist, &mpam_garbage); \ +} while (0) + +static void mpam_class_destroy(struct mpam_class *class) +{ + lockdep_assert_held(&mpam_list_lock); + + list_del_rcu(&class->classes_list); + add_to_garbage(class); +} + +static void mpam_comp_destroy(struct mpam_component *comp) +{ + struct mpam_class *class =3D comp->class; + + lockdep_assert_held(&mpam_list_lock); + + list_del_rcu(&comp->class_list); + add_to_garbage(comp); + + if (list_empty(&class->components)) + mpam_class_destroy(class); +} + +static void mpam_vmsc_destroy(struct mpam_vmsc *vmsc) +{ + struct mpam_component *comp =3D vmsc->comp; + + lockdep_assert_held(&mpam_list_lock); + + list_del_rcu(&vmsc->comp_list); + add_to_garbage(vmsc); + + if (list_empty(&comp->vmsc)) + mpam_comp_destroy(comp); +} + +static void mpam_ris_destroy(struct mpam_msc_ris *ris) +{ + struct mpam_vmsc *vmsc =3D ris->vmsc; + struct mpam_msc *msc =3D vmsc->msc; + struct mpam_component *comp =3D vmsc->comp; + struct mpam_class *class =3D comp->class; + + lockdep_assert_held(&mpam_list_lock); + + /* + * It is assumed affinities don't overlap. If they do the class becomes + * unusable immediately. + */ + cpumask_andnot(&comp->affinity, &comp->affinity, &ris->affinity); + cpumask_andnot(&class->affinity, &class->affinity, &ris->affinity); + clear_bit(ris->ris_idx, &msc->ris_idxs); + list_del_rcu(&ris->vmsc_list); + list_del_rcu(&ris->msc_list); + add_to_garbage(ris); + + if (list_empty(&vmsc->ris)) + mpam_vmsc_destroy(vmsc); +} + +static void mpam_free_garbage(void) +{ + struct mpam_garbage *iter, *tmp; + struct llist_node *to_free =3D llist_del_all(&mpam_garbage); + + if (!to_free) + return; + + synchronize_srcu(&mpam_srcu); + + llist_for_each_entry_safe(iter, tmp, to_free, llist) { + if (iter->pdev) + devm_kfree(&iter->pdev->dev, iter->to_free); + else + kfree(iter->to_free); + } +} + +/* + * The cacheinfo structures are only populated when CPUs are online. + * This helper walks the device tree to include offline CPUs too. + */ +int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, + cpumask_t *affinity) +{ + return acpi_pptt_get_cpumask_from_cache_id(cache_id, affinity); +} + +/* + * cpumask_of_node() only knows about online CPUs. This can't tell us whet= her + * a class is represented on all possible CPUs. + */ +static void get_cpumask_from_node_id(u32 node_id, cpumask_t *affinity) +{ + int cpu; + + for_each_possible_cpu(cpu) { + if (node_id =3D=3D cpu_to_node(cpu)) + cpumask_set_cpu(cpu, affinity); + } +} + +static int mpam_ris_get_affinity(struct mpam_msc *msc, cpumask_t *affinity, + enum mpam_class_types type, + struct mpam_class *class, + struct mpam_component *comp) +{ + int err; + + switch (type) { + case MPAM_CLASS_CACHE: + err =3D mpam_get_cpumask_from_cache_id(comp->comp_id, class->level, + affinity); + if (err) + return err; + + if (cpumask_empty(affinity)) + dev_warn_once(&msc->pdev->dev, + "no CPUs associated with cache node\n"); + + break; + case MPAM_CLASS_MEMORY: + get_cpumask_from_node_id(comp->comp_id, affinity); + /* affinity may be empty for CPU-less memory nodes */ + break; + case MPAM_CLASS_UNKNOWN: + return 0; + } + + cpumask_and(affinity, affinity, &msc->accessibility); + + return 0; +} + +static int mpam_ris_create_locked(struct mpam_msc *msc, u8 ris_idx, + enum mpam_class_types type, u8 class_id, + int component_id) +{ + int err; + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + struct mpam_class *class; + struct mpam_component *comp; + struct platform_device *pdev =3D msc->pdev; + + lockdep_assert_held(&mpam_list_lock); + + if (ris_idx > MPAM_MSC_MAX_NUM_RIS) + return -EINVAL; + + if (test_and_set_bit(ris_idx, &msc->ris_idxs)) + return -EBUSY; + + ris =3D devm_kzalloc(&msc->pdev->dev, sizeof(*ris), GFP_KERNEL); + if (!ris) + return -ENOMEM; + init_garbage(&ris->garbage); + ris->garbage.pdev =3D pdev; + + class =3D mpam_class_find(class_id, type); + if (IS_ERR(class)) + return PTR_ERR(class); + + comp =3D mpam_component_find(class, component_id); + if (IS_ERR(comp)) { + if (list_empty(&class->components)) + mpam_class_destroy(class); + return PTR_ERR(comp); + } + + vmsc =3D mpam_vmsc_find(comp, msc); + if (IS_ERR(vmsc)) { + if (list_empty(&comp->vmsc)) + mpam_comp_destroy(comp); + return PTR_ERR(vmsc); + } + + err =3D mpam_ris_get_affinity(msc, &ris->affinity, type, class, comp); + if (err) { + if (list_empty(&vmsc->ris)) + mpam_vmsc_destroy(vmsc); + return err; + } + + ris->ris_idx =3D ris_idx; + INIT_LIST_HEAD_RCU(&ris->msc_list); + INIT_LIST_HEAD_RCU(&ris->vmsc_list); + ris->vmsc =3D vmsc; + + cpumask_or(&comp->affinity, &comp->affinity, &ris->affinity); + cpumask_or(&class->affinity, &class->affinity, &ris->affinity); + list_add_rcu(&ris->vmsc_list, &vmsc->ris); + + return 0; +} + +int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, + enum mpam_class_types type, u8 class_id, int component_id) +{ + int err; + + mutex_lock(&mpam_list_lock); + err =3D mpam_ris_create_locked(msc, ris_idx, type, class_id, + component_id); + mutex_unlock(&mpam_list_lock); + if (err) + mpam_free_garbage(); + + return err; +} + /* * An MSC can control traffic from a set of CPUs, but may only be accessib= le * from a (hopefully wider) set of CPUs. The common reason for this is pow= er @@ -62,14 +435,25 @@ static int update_msc_accessibility(struct mpam_msc *m= sc) =20 static int fw_num_msc; =20 +/* + * There are two ways of reaching a struct mpam_msc_ris. Via the + * class->component->vmsc->ris, or via the msc. + * When destroying the msc, the other side needs unlinking and cleaning up= too. + */ static void mpam_msc_destroy(struct mpam_msc *msc) { struct platform_device *pdev =3D msc->pdev; + struct mpam_msc_ris *ris, *tmp; =20 lockdep_assert_held(&mpam_list_lock); =20 + list_for_each_entry_safe(ris, tmp, &msc->ris, msc_list) + mpam_ris_destroy(ris); + list_del_rcu(&msc->all_msc_list); platform_set_drvdata(pdev, NULL); + + add_to_garbage(msc); } =20 static void mpam_msc_drv_remove(struct platform_device *pdev) @@ -83,7 +467,7 @@ static void mpam_msc_drv_remove(struct platform_device *= pdev) mpam_msc_destroy(msc); mutex_unlock(&mpam_list_lock); =20 - synchronize_srcu(&mpam_srcu); + mpam_free_garbage(); } =20 static struct mpam_msc *do_mpam_msc_drv_probe(struct platform_device *pdev) @@ -99,6 +483,8 @@ static struct mpam_msc *do_mpam_msc_drv_probe(struct pla= tform_device *pdev) msc =3D devm_kzalloc(&pdev->dev, sizeof(*msc), GFP_KERNEL); if (!msc) return ERR_PTR(-ENOMEM); + init_garbage(&msc->garbage); + msc->garbage.pdev =3D pdev; =20 mutex_init(&msc->probe_lock); mutex_init(&msc->part_sel_lock); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 6ac75f3613c3..1a5d96660382 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -7,14 +7,32 @@ #include #include #include +#include #include #include #include #include #include =20 +#define MPAM_MSC_MAX_NUM_RIS 16 + struct platform_device; =20 +/* + * Structures protected by SRCU may not be freed for a surprising amount of + * time (especially if perf is running). To ensure the MPAM error interrup= t can + * tear down all the structures, build a list of objects that can be gargb= age + * collected once synchronize_srcu() has returned. + * If pdev is non-NULL, use devm_kfree(). + */ +struct mpam_garbage { + /* member of mpam_garbage */ + struct llist_node llist; + + void *to_free; + struct platform_device *pdev; +}; + struct mpam_msc { /* member of mpam_all_msc */ struct list_head all_msc_list; @@ -48,5 +66,80 @@ struct mpam_msc { =20 void __iomem *mapped_hwpage; size_t mapped_hwpage_sz; + + struct mpam_garbage garbage; }; + +struct mpam_class { + /* mpam_components in this class */ + struct list_head components; + + cpumask_t affinity; + + u8 level; + enum mpam_class_types type; + + /* member of mpam_classes */ + struct list_head classes_list; + + struct mpam_garbage garbage; +}; + +struct mpam_component { + u32 comp_id; + + /* mpam_vmsc in this component */ + struct list_head vmsc; + + cpumask_t affinity; + + /* member of mpam_class:components */ + struct list_head class_list; + + /* parent: */ + struct mpam_class *class; + + struct mpam_garbage garbage; +}; + +struct mpam_vmsc { + /* member of mpam_component:vmsc_list */ + struct list_head comp_list; + + /* mpam_msc_ris in this vmsc */ + struct list_head ris; + + /* All RIS in this vMSC are members of this MSC */ + struct mpam_msc *msc; + + /* parent: */ + struct mpam_component *comp; + + struct mpam_garbage garbage; +}; + +struct mpam_msc_ris { + u8 ris_idx; + + cpumask_t affinity; + + /* member of mpam_vmsc:ris */ + struct list_head vmsc_list; + + /* member of mpam_msc:ris */ + struct list_head msc_list; + + /* parent: */ + struct mpam_vmsc *vmsc; + + struct mpam_garbage garbage; +}; + +/* List of all classes - protected by srcu*/ +extern struct srcu_struct mpam_srcu; +extern struct list_head mpam_classes; + +int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, + cpumask_t *affinity); + #endif /* MPAM_INTERNAL_H */ diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h index 3d6c39c667c3..3206f5ddc147 100644 --- a/include/linux/arm_mpam.h +++ b/include/linux/arm_mpam.h @@ -38,11 +38,7 @@ static inline int acpi_mpam_parse_resources(struct mpam_= msc *msc, static inline int acpi_mpam_count_msc(void) { return -EINVAL; } #endif =20 -static inline int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, - enum mpam_class_types type, u8 class_id, - int component_id) -{ - return -EINVAL; -} +int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, + enum mpam_class_types type, u8 class_id, int component_id); =20 #endif /* __LINUX_ARM_MPAM_H */ --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DEAFF33509E; Fri, 17 Oct 2025 18:57:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727475; cv=none; b=K4gafvK+mSEcRhQ6z4/NHHK2rlpWWSHlctrM0E77FhHOeb8iTd/B42LBSFXBIhdGKyNFq+KG0GLGSiulvPmLLVhw2vgdVr+fpFMWGQqnlKNMHeLNy6ecA1d5uIs+rXup66kAOsEkH8hL813MuiR/E3FSjQemawd5XvMruH61aa0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727475; c=relaxed/simple; bh=yabnzx6NmDAIsjuGVvcwZ6vsyUIXIEgHMEQUPm3bj6k=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=OCYcGrhO5I/EQccHu53xfHDqSjEp4z/I8XlpmM+xOOXEp3uVraGHeBAI/04IVJo014SIIdPeM0g9buGMwp1lF44NXjkmCMQmo96C5RtzAoautgzSzpbwH4ugvJDzEaLpnxETpZcRHI9dAZIv0HiIqbRYJPfY3t4Q/8h1OqVDx1k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9E93F1595; Fri, 17 Oct 2025 11:57:45 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7B77D3F66E; Fri, 17 Oct 2025 11:57:48 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 09/29] arm_mpam: Add MPAM MSC register layout definitions Date: Fri, 17 Oct 2025 18:56:25 +0000 Message-Id: <20251017185645.26604-10-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Memory Partitioning and Monitoring (MPAM) has memory mapped devices (MSCs) with an identity/configuration page. Add the definitions for these registers as offset within the page(s). Link: https://developer.arm.com/documentation/ihi0099/latest/ Signed-off-by: James Morse Reviewed-by: Ben Horgan Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Reviewed-by: Jonathan Cameron Tested-by: Peter Newman --- Changes since v2: * Removed a few colons. * fixed a typo. * Moved some definitions around. Changes since v1: * Whitespace. * Added constants for CASSOC and XCL. * Merged FLT/CTL defines. * Fixed MSMON_CFG_CSU_CTL_TYPE_CSU definition. Changes since RFC: * Renamed MSMON_CFG_MBWU_CTL_TYPE_CSU as MSMON_CFG_CSU_CTL_TYPE_CSU * Whitepsace churn. * Cite a more recent document. * Removed some stale feature, fixed some names etc. --- drivers/resctrl/mpam_internal.h | 268 ++++++++++++++++++++++++++++++++ 1 file changed, 268 insertions(+) diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 1a5d96660382..1ef3e8e1d056 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -142,4 +142,272 @@ extern struct list_head mpam_classes; int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, cpumask_t *affinity); =20 +/* + * MPAM MSCs have the following register layout. See: + * Arm Memory System Resource Partitioning and Monitoring (MPAM) System + * Component Specification. + * https://developer.arm.com/documentation/ihi0099/latest/ + */ +#define MPAM_ARCHITECTURE_V1 0x10 + +/* Memory mapped control pages */ +/* ID Register offsets in the memory mapped page */ +#define MPAMF_IDR 0x0000 /* features id register */ +#define MPAMF_IIDR 0x0018 /* implementer id register */ +#define MPAMF_AIDR 0x0020 /* architectural id register */ +#define MPAMF_IMPL_IDR 0x0028 /* imp-def partitioning */ +#define MPAMF_CPOR_IDR 0x0030 /* cache-portion partitioning */ +#define MPAMF_CCAP_IDR 0x0038 /* cache-capacity partitioning */ +#define MPAMF_MBW_IDR 0x0040 /* mem-bw partitioning */ +#define MPAMF_PRI_IDR 0x0048 /* priority partitioning */ +#define MPAMF_MSMON_IDR 0x0080 /* performance monitoring features */ +#define MPAMF_CSUMON_IDR 0x0088 /* cache-usage monitor */ +#define MPAMF_MBWUMON_IDR 0x0090 /* mem-bw usage monitor */ +#define MPAMF_PARTID_NRW_IDR 0x0050 /* partid-narrowing */ + +/* Configuration and Status Register offsets in the memory mapped page */ +#define MPAMCFG_PART_SEL 0x0100 /* partid to configure */ +#define MPAMCFG_CPBM 0x1000 /* cache-portion config */ +#define MPAMCFG_CMAX 0x0108 /* cache-capacity config */ +#define MPAMCFG_CMIN 0x0110 /* cache-capacity config */ +#define MPAMCFG_CASSOC 0x0118 /* cache-associativity config */ +#define MPAMCFG_MBW_MIN 0x0200 /* min mem-bw config */ +#define MPAMCFG_MBW_MAX 0x0208 /* max mem-bw config */ +#define MPAMCFG_MBW_WINWD 0x0220 /* mem-bw accounting window config */ +#define MPAMCFG_MBW_PBM 0x2000 /* mem-bw portion bitmap config */ +#define MPAMCFG_PRI 0x0400 /* priority partitioning config */ +#define MPAMCFG_MBW_PROP 0x0500 /* mem-bw stride config */ +#define MPAMCFG_INTPARTID 0x0600 /* partid-narrowing config */ + +#define MSMON_CFG_MON_SEL 0x0800 /* monitor selector */ +#define MSMON_CFG_CSU_FLT 0x0810 /* cache-usage monitor filter */ +#define MSMON_CFG_CSU_CTL 0x0818 /* cache-usage monitor config */ +#define MSMON_CFG_MBWU_FLT 0x0820 /* mem-bw monitor filter */ +#define MSMON_CFG_MBWU_CTL 0x0828 /* mem-bw monitor config */ +#define MSMON_CSU 0x0840 /* current cache-usage */ +#define MSMON_CSU_CAPTURE 0x0848 /* last cache-usage value captured */ +#define MSMON_MBWU 0x0860 /* current mem-bw usage value */ +#define MSMON_MBWU_CAPTURE 0x0868 /* last mem-bw value captured */ +#define MSMON_MBWU_L 0x0880 /* current long mem-bw usage value */ +#define MSMON_MBWU_CAPTURE_L 0x0890 /* last long mem-bw value captured */ +#define MSMON_CAPT_EVNT 0x0808 /* signal a capture event */ +#define MPAMF_ESR 0x00F8 /* error status register */ +#define MPAMF_ECR 0x00F0 /* error control register */ + +/* MPAMF_IDR - MPAM features ID register */ +#define MPAMF_IDR_PARTID_MAX GENMASK(15, 0) +#define MPAMF_IDR_PMG_MAX GENMASK(23, 16) +#define MPAMF_IDR_HAS_CCAP_PART BIT(24) +#define MPAMF_IDR_HAS_CPOR_PART BIT(25) +#define MPAMF_IDR_HAS_MBW_PART BIT(26) +#define MPAMF_IDR_HAS_PRI_PART BIT(27) +#define MPAMF_IDR_EXT BIT(28) +#define MPAMF_IDR_HAS_IMPL_IDR BIT(29) +#define MPAMF_IDR_HAS_MSMON BIT(30) +#define MPAMF_IDR_HAS_PARTID_NRW BIT(31) +#define MPAMF_IDR_HAS_RIS BIT(32) +#define MPAMF_IDR_HAS_EXTD_ESR BIT(38) +#define MPAMF_IDR_HAS_ESR BIT(39) +#define MPAMF_IDR_RIS_MAX GENMASK(59, 56) + +/* MPAMF_MSMON_IDR - MPAM performance monitoring ID register */ +#define MPAMF_MSMON_IDR_MSMON_CSU BIT(16) +#define MPAMF_MSMON_IDR_MSMON_MBWU BIT(17) +#define MPAMF_MSMON_IDR_HAS_LOCAL_CAPT_EVNT BIT(31) + +/* MPAMF_CPOR_IDR - MPAM features cache portion partitioning ID register */ +#define MPAMF_CPOR_IDR_CPBM_WD GENMASK(15, 0) + +/* MPAMF_CCAP_IDR - MPAM features cache capacity partitioning ID register = */ +#define MPAMF_CCAP_IDR_CMAX_WD GENMASK(5, 0) +#define MPAMF_CCAP_IDR_CASSOC_WD GENMASK(12, 8) +#define MPAMF_CCAP_IDR_HAS_CASSOC BIT(28) +#define MPAMF_CCAP_IDR_HAS_CMIN BIT(29) +#define MPAMF_CCAP_IDR_NO_CMAX BIT(30) +#define MPAMF_CCAP_IDR_HAS_CMAX_SOFTLIM BIT(31) + +/* MPAMF_MBW_IDR - MPAM features memory bandwidth partitioning ID register= */ +#define MPAMF_MBW_IDR_BWA_WD GENMASK(5, 0) +#define MPAMF_MBW_IDR_HAS_MIN BIT(10) +#define MPAMF_MBW_IDR_HAS_MAX BIT(11) +#define MPAMF_MBW_IDR_HAS_PBM BIT(12) +#define MPAMF_MBW_IDR_HAS_PROP BIT(13) +#define MPAMF_MBW_IDR_WINDWR BIT(14) +#define MPAMF_MBW_IDR_BWPBM_WD GENMASK(28, 16) + +/* MPAMF_PRI_IDR - MPAM features priority partitioning ID register */ +#define MPAMF_PRI_IDR_HAS_INTPRI BIT(0) +#define MPAMF_PRI_IDR_INTPRI_0_IS_LOW BIT(1) +#define MPAMF_PRI_IDR_INTPRI_WD GENMASK(9, 4) +#define MPAMF_PRI_IDR_HAS_DSPRI BIT(16) +#define MPAMF_PRI_IDR_DSPRI_0_IS_LOW BIT(17) +#define MPAMF_PRI_IDR_DSPRI_WD GENMASK(25, 20) + +/* MPAMF_CSUMON_IDR - MPAM cache storage usage monitor ID register */ +#define MPAMF_CSUMON_IDR_NUM_MON GENMASK(15, 0) +#define MPAMF_CSUMON_IDR_HAS_OFLOW_CAPT BIT(24) +#define MPAMF_CSUMON_IDR_HAS_CEVNT_OFLW BIT(25) +#define MPAMF_CSUMON_IDR_HAS_OFSR BIT(26) +#define MPAMF_CSUMON_IDR_HAS_OFLOW_LNKG BIT(27) +#define MPAMF_CSUMON_IDR_HAS_XCL BIT(29) +#define MPAMF_CSUMON_IDR_CSU_RO BIT(30) +#define MPAMF_CSUMON_IDR_HAS_CAPTURE BIT(31) + +/* MPAMF_MBWUMON_IDR - MPAM memory bandwidth usage monitor ID register */ +#define MPAMF_MBWUMON_IDR_NUM_MON GENMASK(15, 0) +#define MPAMF_MBWUMON_IDR_HAS_RWBW BIT(28) +#define MPAMF_MBWUMON_IDR_LWD BIT(29) +#define MPAMF_MBWUMON_IDR_HAS_LONG BIT(30) +#define MPAMF_MBWUMON_IDR_HAS_CAPTURE BIT(31) + +/* MPAMF_PARTID_NRW_IDR - MPAM PARTID narrowing ID register */ +#define MPAMF_PARTID_NRW_IDR_INTPARTID_MAX GENMASK(15, 0) + +/* MPAMF_IIDR - MPAM implementation ID register */ +#define MPAMF_IIDR_IMPLEMENTER GENMASK(11, 0) +#define MPAMF_IIDR_REVISION GENMASK(15, 12) +#define MPAMF_IIDR_VARIANT GENMASK(19, 16) +#define MPAMF_IIDR_PRODUCTID GENMASK(31, 20) + +/* MPAMF_AIDR - MPAM architecture ID register */ +#define MPAMF_AIDR_ARCH_MINOR_REV GENMASK(3, 0) +#define MPAMF_AIDR_ARCH_MAJOR_REV GENMASK(7, 4) + +/* MPAMCFG_PART_SEL - MPAM partition configuration selection register */ +#define MPAMCFG_PART_SEL_PARTID_SEL GENMASK(15, 0) +#define MPAMCFG_PART_SEL_INTERNAL BIT(16) +#define MPAMCFG_PART_SEL_RIS GENMASK(27, 24) + +/* MPAMCFG_CASSOC - MPAM cache maximum associativity partition configurati= on register */ +#define MPAMCFG_CASSOC_CASSOC GENMASK(15, 0) + +/* MPAMCFG_CMAX - MPAM cache capacity configuration register */ +#define MPAMCFG_CMAX_SOFTLIM BIT(31) +#define MPAMCFG_CMAX_CMAX GENMASK(15, 0) + +/* MPAMCFG_CMIN - MPAM cache capacity configuration register */ +#define MPAMCFG_CMIN_CMIN GENMASK(15, 0) + +/* + * MPAMCFG_MBW_MIN - MPAM memory minimum bandwidth partitioning configurat= ion + * register + */ +#define MPAMCFG_MBW_MIN_MIN GENMASK(15, 0) + +/* + * MPAMCFG_MBW_MAX - MPAM memory maximum bandwidth partitioning configurat= ion + * register + */ +#define MPAMCFG_MBW_MAX_MAX GENMASK(15, 0) +#define MPAMCFG_MBW_MAX_HARDLIM BIT(31) + +/* + * MPAMCFG_MBW_WINWD - MPAM memory bandwidth partitioning window width + * register + */ +#define MPAMCFG_MBW_WINWD_US_FRAC GENMASK(7, 0) +#define MPAMCFG_MBW_WINWD_US_INT GENMASK(23, 8) + +/* MPAMCFG_PRI - MPAM priority partitioning configuration register */ +#define MPAMCFG_PRI_INTPRI GENMASK(15, 0) +#define MPAMCFG_PRI_DSPRI GENMASK(31, 16) + +/* + * MPAMCFG_MBW_PROP - Memory bandwidth proportional stride partitioning + * configuration register + */ +#define MPAMCFG_MBW_PROP_STRIDEM1 GENMASK(15, 0) +#define MPAMCFG_MBW_PROP_EN BIT(31) + +/* + * MPAMCFG_INTPARTID - MPAM internal partition narrowing configuration reg= ister + */ +#define MPAMCFG_INTPARTID_INTPARTID GENMASK(15, 0) +#define MPAMCFG_INTPARTID_INTERNAL BIT(16) + +/* MSMON_CFG_MON_SEL - Memory system performance monitor selection registe= r */ +#define MSMON_CFG_MON_SEL_MON_SEL GENMASK(15, 0) +#define MSMON_CFG_MON_SEL_RIS GENMASK(27, 24) + +/* MPAMF_ESR - MPAM Error Status Register */ +#define MPAMF_ESR_PARTID_MON GENMASK(15, 0) +#define MPAMF_ESR_PMG GENMASK(23, 16) +#define MPAMF_ESR_ERRCODE GENMASK(27, 24) +#define MPAMF_ESR_OVRWR BIT(31) +#define MPAMF_ESR_RIS GENMASK(35, 32) + +/* MPAMF_ECR - MPAM Error Control Register */ +#define MPAMF_ECR_INTEN BIT(0) + +/* Error conditions in accessing memory mapped registers */ +#define MPAM_ERRCODE_NONE 0 +#define MPAM_ERRCODE_PARTID_SEL_RANGE 1 +#define MPAM_ERRCODE_REQ_PARTID_RANGE 2 +#define MPAM_ERRCODE_MSMONCFG_ID_RANGE 3 +#define MPAM_ERRCODE_REQ_PMG_RANGE 4 +#define MPAM_ERRCODE_MONITOR_RANGE 5 +#define MPAM_ERRCODE_INTPARTID_RANGE 6 +#define MPAM_ERRCODE_UNEXPECTED_INTERNAL 7 +#define MPAM_ERRCODE_UNDEFINED_RIS_PART_SEL 8 +#define MPAM_ERRCODE_RIS_NO_CONTROL 9 +#define MPAM_ERRCODE_UNDEFINED_RIS_MON_SEL 10 +#define MPAM_ERRCODE_RIS_NO_MONITOR 11 + +/* + * MSMON_CFG_CSU_CTL - Memory system performance monitor configure cache s= torage + * usage monitor control register + * MSMON_CFG_MBWU_CTL - Memory system performance monitor configure memory + * bandwidth usage monitor control register + */ +#define MSMON_CFG_x_CTL_TYPE GENMASK(7, 0) +#define MSMON_CFG_MBWU_CTL_OFLOW_STATUS_L BIT(15) +#define MSMON_CFG_x_CTL_MATCH_PARTID BIT(16) +#define MSMON_CFG_x_CTL_MATCH_PMG BIT(17) +#define MSMON_CFG_x_CTL_SUBTYPE GENMASK(22, 20) +#define MSMON_CFG_x_CTL_OFLOW_FRZ BIT(24) +#define MSMON_CFG_x_CTL_OFLOW_INTR BIT(25) +#define MSMON_CFG_x_CTL_OFLOW_STATUS BIT(26) +#define MSMON_CFG_x_CTL_CAPT_RESET BIT(27) +#define MSMON_CFG_x_CTL_CAPT_EVNT GENMASK(30, 28) +#define MSMON_CFG_x_CTL_EN BIT(31) + +#define MSMON_CFG_MBWU_CTL_TYPE_MBWU 0x42 +#define MSMON_CFG_CSU_CTL_TYPE_CSU 0x43 + +#define MSMON_CFG_MBWU_CTL_SCLEN BIT(19) + +/* + * MSMON_CFG_CSU_FLT - Memory system performance monitor configure cache = storage + * usage monitor filter register + * MSMON_CFG_MBWU_FLT - Memory system performance monitor configure memory + * bandwidth usage monitor filter register + */ +#define MSMON_CFG_x_FLT_PARTID GENMASK(15, 0) +#define MSMON_CFG_x_FLT_PMG GENMASK(23, 16) + +#define MSMON_CFG_MBWU_FLT_RWBW GENMASK(31, 30) +#define MSMON_CFG_CSU_FLT_XCL BIT(31) + +/* + * MSMON_CSU - Memory system performance monitor cache storage usage monit= or + * register + * MSMON_CSU_CAPTURE - Memory system performance monitor cache storage us= age + * capture register + * MSMON_MBWU - Memory system performance monitor memory bandwidth usage + * monitor register + * MSMON_MBWU_CAPTURE - Memory system performance monitor memory bandwidth= usage + * capture register + */ +#define MSMON___VALUE GENMASK(30, 0) +#define MSMON___NRDY BIT(31) +#define MSMON___NRDY_L BIT(63) +#define MSMON___L_VALUE GENMASK(43, 0) +#define MSMON___LWD_VALUE GENMASK(62, 0) + +/* + * MSMON_CAPT_EVNT - Memory system performance monitoring capture event + * generation register + */ +#define MSMON_CAPT_EVNT_NOW BIT(0) + #endif /* MPAM_INTERNAL_H */ --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 77C0A336ED3; Fri, 17 Oct 2025 18:57:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727481; cv=none; b=RZy9oEpauRPhIa9RvS1xt7uCvOm2ChZGUvjpx98AiuJPmBMH+0v/kDqj8NDJQXq4pC6J5M9VddnkJoeNgVTeDvpUKhepAHbaPM2sx+x4/Q7/gkcqX72UHpTipUNNsfwpvcA9sNvFiosT8bOR7Bkerl5qgW8kz45XCphHuzNdFac= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727481; c=relaxed/simple; bh=7NGmgRNWMr+QyBTsGmXvrTp8WAk6sR56X8yDT+jNlO4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=HrSfFdFBYsGv2yZbCvc/Yo42rsugw2bu/h0D6uXxk5gOAZxz7wkmJalInz/QuRNWDJWSYU5h98F9712oDkcB2hYl0Qa+SgZp+Wq8jEaIiqNYc2khWHJBmrVO3wTsT908VsU4rCI+WP0nNBvYH6+WpUo4hHpHpJD2G8PTeMT1SJA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 222DF1596; Fri, 17 Oct 2025 11:57:51 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D20263F66E; Fri, 17 Oct 2025 11:57:53 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Lecopzer Chen , Ben Horgan Subject: [PATCH v3 10/29] arm_mpam: Add cpuhp callbacks to probe MSC hardware Date: Fri, 17 Oct 2025 18:56:26 +0000 Message-Id: <20251017185645.26604-11-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Because an MSC can only by accessed from the CPUs in its cpu-affinity set we need to be running on one of those CPUs to probe the MSC hardware. Do this work in the cpuhp callback. Probing the hardware will only happen before MPAM is enabled, walk all the MSCs and probe those we can reach that haven't already been probed as each CPU's online call is made. This adds the low-level MSC register accessors. Once all MSCs reported by the firmware have been probed from a CPU in their respective cpu-affinity set, the probe-time cpuhp callbacks are replaced. The replacement callbacks will ultimately need to handle save/restore of the runtime MSC state across power transitions, but for now there is nothing to do in them: so do nothing. The architecture's context switch code will be enabled by a static-key, this can be set by mpam_enable(), but must be done from process context, not a cpuhp callback because both take the cpuhp lock. Whenever a new MSC has been probed, the mpam_enable() work is scheduled to test if all the MSCs have been probed. If probing fails, mpam_disable() is scheduled to unregister the cpuhp callbacks and free memory. CC: Lecopzer Chen Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Reviewed-by: Fenghua Yu Reviewed-by: Gavin Shan Tested-by: Fenghua Yu Tested-by: Peter Newman --- Change since v2: * Simplified to if(err) break. * Pass name to mpam_register_cpuhp_callbacks() to allow the two callback types to be discerned in debugfs. Changes since v1: * Removed register bounds check. If the firmware tables are wrong the resulting translation fault should be enough to debug this. * Removed '&' in front of a function pointer. * Pulled mpam_disable() into this patch. * Disable mpam when probing fails to avoid extra work on broken platforms. * Added mpam_disbale_reason as there are now two non-debug reasons for this to happen. --- drivers/resctrl/mpam_devices.c | 174 +++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 5 + 2 files changed, 178 insertions(+), 1 deletion(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 8685e50f08c6..49f874fae0a6 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -4,6 +4,7 @@ #define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__ =20 #include +#include #include #include #include @@ -19,6 +20,7 @@ #include #include #include +#include =20 #include "mpam_internal.h" =20 @@ -38,6 +40,25 @@ struct srcu_struct mpam_srcu; */ static atomic_t mpam_num_msc; =20 +static int mpam_cpuhp_state; +static DEFINE_MUTEX(mpam_cpuhp_state_lock); + +/* + * mpam is enabled once all devices have been probed from CPU online callb= acks, + * scheduled via this work_struct. If access to an MSC depends on a CPU th= at + * was not brought online at boot, this can happen surprisingly late. + */ +static DECLARE_WORK(mpam_enable_work, &mpam_enable); + +/* + * All mpam error interrupts indicate a software bug. On receipt, disable = the + * driver. + */ +static DECLARE_WORK(mpam_broken_work, &mpam_disable); + +/* When mpam is disabled, the printed reason to aid debugging */ +static char *mpam_disable_reason; + /* * An MSC is a physical container for controls and monitors, each identifi= ed by * their RIS index. These share a base-address, interrupts and some MMIO @@ -81,6 +102,20 @@ static inline void init_garbage(struct mpam_garbage *ga= rbage) { init_llist_node(&garbage->llist); } +static u32 __mpam_read_reg(struct mpam_msc *msc, u16 reg) +{ + WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); + + return readl_relaxed(msc->mapped_hwpage + reg); +} + +static inline u32 _mpam_read_partsel_reg(struct mpam_msc *msc, u16 reg) +{ + lockdep_assert_held_once(&msc->part_sel_lock); + return __mpam_read_reg(msc, reg); +} + +#define mpam_read_partsel_reg(msc, reg) _mpam_read_partsel_reg(msc,= MPAMF_##reg) =20 static struct mpam_vmsc * mpam_vmsc_alloc(struct mpam_component *comp, struct mpam_msc *msc) @@ -411,6 +446,86 @@ int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, return err; } =20 +static int mpam_msc_hw_probe(struct mpam_msc *msc) +{ + u64 idr; + struct device *dev =3D &msc->pdev->dev; + + lockdep_assert_held(&msc->probe_lock); + + idr =3D __mpam_read_reg(msc, MPAMF_AIDR); + if ((idr & MPAMF_AIDR_ARCH_MAJOR_REV) !=3D MPAM_ARCHITECTURE_V1) { + dev_err_once(dev, "MSC does not match MPAM architecture v1.x\n"); + return -EIO; + } + + msc->probed =3D true; + + return 0; +} + +static int mpam_cpu_online(unsigned int cpu) +{ + return 0; +} + +/* Before mpam is enabled, try to probe new MSC */ +static int mpam_discovery_cpu_online(unsigned int cpu) +{ + int err =3D 0; + struct mpam_msc *msc; + bool new_device_probed =3D false; + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!cpumask_test_cpu(cpu, &msc->accessibility)) + continue; + + mutex_lock(&msc->probe_lock); + if (!msc->probed) + err =3D mpam_msc_hw_probe(msc); + mutex_unlock(&msc->probe_lock); + + if (err) + break; + new_device_probed =3D true; + } + + if (new_device_probed && !err) + schedule_work(&mpam_enable_work); + if (err) { + mpam_disable_reason =3D "error during probing"; + schedule_work(&mpam_broken_work); + } + + return err; +} + +static int mpam_cpu_offline(unsigned int cpu) +{ + return 0; +} + +static void mpam_register_cpuhp_callbacks(int (*online)(unsigned int onlin= e), + int (*offline)(unsigned int offline), + char *name) +{ + mutex_lock(&mpam_cpuhp_state_lock); + if (mpam_cpuhp_state) { + cpuhp_remove_state(mpam_cpuhp_state); + mpam_cpuhp_state =3D 0; + } + + mpam_cpuhp_state =3D cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, name, online, + offline); + if (mpam_cpuhp_state <=3D 0) { + pr_err("Failed to register cpuhp callbacks"); + mpam_cpuhp_state =3D 0; + } + mutex_unlock(&mpam_cpuhp_state_lock); +} + /* * An MSC can control traffic from a set of CPUs, but may only be accessib= le * from a (hopefully wider) set of CPUs. The common reason for this is pow= er @@ -544,7 +659,8 @@ static int mpam_msc_drv_probe(struct platform_device *p= dev) } =20 if (!err && atomic_add_return(1, &mpam_num_msc) =3D=3D fw_num_msc) - pr_info("Discovered all MSC\n"); + mpam_register_cpuhp_callbacks(mpam_discovery_cpu_online, NULL, + "mpam:drv_probe"); =20 return err; } @@ -557,6 +673,62 @@ static struct platform_driver mpam_msc_driver =3D { .remove =3D mpam_msc_drv_remove, }; =20 +static void mpam_enable_once(void) +{ + mpam_register_cpuhp_callbacks(mpam_cpu_online, mpam_cpu_offline, + "mpam:online"); + + pr_info("MPAM enabled\n"); +} + +void mpam_disable(struct work_struct *ignored) +{ + struct mpam_msc *msc, *tmp; + + mutex_lock(&mpam_cpuhp_state_lock); + if (mpam_cpuhp_state) { + cpuhp_remove_state(mpam_cpuhp_state); + mpam_cpuhp_state =3D 0; + } + mutex_unlock(&mpam_cpuhp_state_lock); + + mutex_lock(&mpam_list_lock); + list_for_each_entry_safe(msc, tmp, &mpam_all_msc, all_msc_list) + mpam_msc_destroy(msc); + mutex_unlock(&mpam_list_lock); + mpam_free_garbage(); + + pr_err_once("MPAM disabled due to %s\n", mpam_disable_reason); +} + +/* + * Enable mpam once all devices have been probed. + * Scheduled by mpam_discovery_cpu_online() once all devices have been cre= ated. + * Also scheduled when new devices are probed when new CPUs come online. + */ +void mpam_enable(struct work_struct *work) +{ + static atomic_t once; + struct mpam_msc *msc; + bool all_devices_probed =3D true; + + /* Have we probed all the hw devices? */ + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, + srcu_read_lock_held(&mpam_srcu)) { + mutex_lock(&msc->probe_lock); + if (!msc->probed) + all_devices_probed =3D false; + mutex_unlock(&msc->probe_lock); + + if (!all_devices_probed) + break; + } + + if (all_devices_probed && !atomic_fetch_inc(&once)) + mpam_enable_once(); +} + static int __init mpam_msc_driver_init(void) { if (!system_supports_mpam()) diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 1ef3e8e1d056..8865a7d81dd1 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -50,6 +50,7 @@ struct mpam_msc { * properties become read-only and the lists are protected by SRCU. */ struct mutex probe_lock; + bool probed; unsigned long ris_idxs; u32 ris_max; =20 @@ -139,6 +140,10 @@ struct mpam_msc_ris { extern struct srcu_struct mpam_srcu; extern struct list_head mpam_classes; =20 +/* Scheduled work callback to enable mpam once all MSC have been probed */ +void mpam_enable(struct work_struct *work); +void mpam_disable(struct work_struct *work); + int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, cpumask_t *affinity); =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 28603332EDB; Fri, 17 Oct 2025 18:58:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727486; cv=none; b=eLCf2wdPOZd+MS28S8iAgJyX6vuVwJ3918tSakV2bd2D1GAXjjzfsPyVR8EcV0c4iGQJY9Ur/dSJmx0Tp17GKOd3KtE0+PZtMd8md+rp9ZrLWQbrk5aVWPjjLR84Wgk5d2SbPGLDHVxr1Ox7pCTK46JzsFBAUE345jtGxE5+MqA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727486; c=relaxed/simple; bh=+NI67xWn1SSXsCruSU01Wt0mc2ZIusm58+7uUBNGN64=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hzpYoOPGei2DHFsioNmeiZ4FGc/V9zpLnr/ZSAbWtA6JKSF/Rv1GZFIbuLxLuxF40J/BDbCkkwRbeRH+80WFt9F4XbR3S/qHKn5XXQoaNMQO4VbCTuLKPnQY7wf4x5GY3P8Z5c2zd35QXQXI5gatAlCAsXFe/xSR3PT8n/kHOyg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 792CD1596; Fri, 17 Oct 2025 11:57:56 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 566133F66E; Fri, 17 Oct 2025 11:57:59 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 11/29] arm_mpam: Probe hardware to find the supported partid/pmg values Date: Fri, 17 Oct 2025 18:56:27 +0000 Message-Id: <20251017185645.26604-12-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" CPUs can generate traffic with a range of PARTID and PMG values, but each MSC may also have its own maximum size for these fields. Before MPAM can be used, the driver needs to probe each RIS on each MSC, to find the system-wide smallest value that can be used. The limits from requestors (e.g. CPUs) also need taking into account. While doing this, RIS entries that firmware didn't describe are created under MPAM_CLASS_UNKNOWN. While we're here, implement the mpam_register_requestor() call for the arch code to register the CPU limits. Future callers of this will tell us about the SMMU and ITS. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Simplified return of mpam_get_or_create_ris() * Used guard() in mpam_register_requestor() * whitespace, * >=3D rather than > in a bounds checking warning. * Added comment explaining why printk() is counter-intuitively used. Changes since v1: * Change to lock ordering now that the list-lock mutex isn't held from the cpuhp call. * Removed irq-unmaksed assert in requestor register. * Changed captialisation in print message. --- drivers/resctrl/mpam_devices.c | 148 +++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 6 ++ include/linux/arm_mpam.h | 14 +++ 3 files changed, 167 insertions(+), 1 deletion(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 49f874fae0a6..910bb6cd5e4f 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -43,6 +44,15 @@ static atomic_t mpam_num_msc; static int mpam_cpuhp_state; static DEFINE_MUTEX(mpam_cpuhp_state_lock); =20 +/* + * The smallest common values for any CPU or MSC in the system. + * Generating traffic outside this range will result in screaming interrup= ts. + */ +u16 mpam_partid_max; +u8 mpam_pmg_max; +static bool partid_max_init, partid_max_published; +static DEFINE_SPINLOCK(partid_max_lock); + /* * mpam is enabled once all devices have been probed from CPU online callb= acks, * scheduled via this work_struct. If access to an MSC depends on a CPU th= at @@ -117,6 +127,69 @@ static inline u32 _mpam_read_partsel_reg(struct mpam_m= sc *msc, u16 reg) =20 #define mpam_read_partsel_reg(msc, reg) _mpam_read_partsel_reg(msc,= MPAMF_##reg) =20 +static void __mpam_write_reg(struct mpam_msc *msc, u16 reg, u32 val) +{ + WARN_ON_ONCE(reg + sizeof(u32) >=3D msc->mapped_hwpage_sz); + WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); + + writel_relaxed(val, msc->mapped_hwpage + reg); +} + +static inline void _mpam_write_partsel_reg(struct mpam_msc *msc, u16 reg, = u32 val) +{ + lockdep_assert_held_once(&msc->part_sel_lock); + __mpam_write_reg(msc, reg, val); +} +#define mpam_write_partsel_reg(msc, reg, val) _mpam_write_partsel_reg(msc= , MPAMCFG_##reg, val) + +static u64 mpam_msc_read_idr(struct mpam_msc *msc) +{ + u64 idr_high =3D 0, idr_low; + + lockdep_assert_held(&msc->part_sel_lock); + + idr_low =3D mpam_read_partsel_reg(msc, IDR); + if (FIELD_GET(MPAMF_IDR_EXT, idr_low)) + idr_high =3D mpam_read_partsel_reg(msc, IDR + 4); + + return (idr_high << 32) | idr_low; +} + +static void __mpam_part_sel_raw(u32 partsel, struct mpam_msc *msc) +{ + lockdep_assert_held(&msc->part_sel_lock); + + mpam_write_partsel_reg(msc, PART_SEL, partsel); +} + +static void __mpam_part_sel(u8 ris_idx, u16 partid, struct mpam_msc *msc) +{ + u32 partsel =3D FIELD_PREP(MPAMCFG_PART_SEL_RIS, ris_idx) | + FIELD_PREP(MPAMCFG_PART_SEL_PARTID_SEL, partid); + + __mpam_part_sel_raw(partsel, msc); +} + +int mpam_register_requestor(u16 partid_max, u8 pmg_max) +{ + guard(spinlock)(&partid_max_lock); + if (!partid_max_init) { + mpam_partid_max =3D partid_max; + mpam_pmg_max =3D pmg_max; + partid_max_init =3D true; + } else if (!partid_max_published) { + mpam_partid_max =3D min(mpam_partid_max, partid_max); + mpam_pmg_max =3D min(mpam_pmg_max, pmg_max); + } else { + /* New requestors can't lower the values */ + if (partid_max < mpam_partid_max || pmg_max < mpam_pmg_max) + return -EBUSY; + } + + return 0; +} +EXPORT_SYMBOL(mpam_register_requestor); + static struct mpam_vmsc * mpam_vmsc_alloc(struct mpam_component *comp, struct mpam_msc *msc) { @@ -427,6 +500,7 @@ static int mpam_ris_create_locked(struct mpam_msc *msc,= u8 ris_idx, cpumask_or(&comp->affinity, &comp->affinity, &ris->affinity); cpumask_or(&class->affinity, &class->affinity, &ris->affinity); list_add_rcu(&ris->vmsc_list, &vmsc->ris); + list_add_rcu(&ris->msc_list, &msc->ris); =20 return 0; } @@ -446,9 +520,36 @@ int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, return err; } =20 +static struct mpam_msc_ris *mpam_get_or_create_ris(struct mpam_msc *msc, + u8 ris_idx) +{ + int err; + struct mpam_msc_ris *ris; + + lockdep_assert_held(&mpam_list_lock); + + if (!test_bit(ris_idx, &msc->ris_idxs)) { + err =3D mpam_ris_create_locked(msc, ris_idx, MPAM_CLASS_UNKNOWN, + 0, 0); + if (err) + return ERR_PTR(err); + } + + list_for_each_entry(ris, &msc->ris, msc_list) { + if (ris->ris_idx =3D=3D ris_idx) { + return ris; + } + } + + return ERR_PTR(-ENOENT); +} + static int mpam_msc_hw_probe(struct mpam_msc *msc) { u64 idr; + u16 partid_max; + u8 ris_idx, pmg_max; + struct mpam_msc_ris *ris; struct device *dev =3D &msc->pdev->dev; =20 lockdep_assert_held(&msc->probe_lock); @@ -459,6 +560,40 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) return -EIO; } =20 + /* Grab an IDR value to find out how many RIS there are */ + mutex_lock(&msc->part_sel_lock); + idr =3D mpam_msc_read_idr(msc); + mutex_unlock(&msc->part_sel_lock); + + msc->ris_max =3D FIELD_GET(MPAMF_IDR_RIS_MAX, idr); + + /* Use these values so partid/pmg always starts with a valid value */ + msc->partid_max =3D FIELD_GET(MPAMF_IDR_PARTID_MAX, idr); + msc->pmg_max =3D FIELD_GET(MPAMF_IDR_PMG_MAX, idr); + + for (ris_idx =3D 0; ris_idx <=3D msc->ris_max; ris_idx++) { + mutex_lock(&msc->part_sel_lock); + __mpam_part_sel(ris_idx, 0, msc); + idr =3D mpam_msc_read_idr(msc); + mutex_unlock(&msc->part_sel_lock); + + partid_max =3D FIELD_GET(MPAMF_IDR_PARTID_MAX, idr); + pmg_max =3D FIELD_GET(MPAMF_IDR_PMG_MAX, idr); + msc->partid_max =3D min(msc->partid_max, partid_max); + msc->pmg_max =3D min(msc->pmg_max, pmg_max); + + mutex_lock(&mpam_list_lock); + ris =3D mpam_get_or_create_ris(msc, ris_idx); + mutex_unlock(&mpam_list_lock); + if (IS_ERR(ris)) + return PTR_ERR(ris); + } + + spin_lock(&partid_max_lock); + mpam_partid_max =3D min(mpam_partid_max, msc->partid_max); + mpam_pmg_max =3D min(mpam_pmg_max, msc->pmg_max); + spin_unlock(&partid_max_lock); + msc->probed =3D true; =20 return 0; @@ -675,10 +810,20 @@ static struct platform_driver mpam_msc_driver =3D { =20 static void mpam_enable_once(void) { + /* + * Once the cpuhp callbacks have been changed, mpam_partid_max can no + * longer change. + */ + spin_lock(&partid_max_lock); + partid_max_published =3D true; + spin_unlock(&partid_max_lock); + mpam_register_cpuhp_callbacks(mpam_cpu_online, mpam_cpu_offline, "mpam:online"); =20 - pr_info("MPAM enabled\n"); + /* Use printk() to avoid the pr_fmt adding the function name. */ + printk(KERN_INFO, "MPAM enabled with %u PARTIDs and %u PMGs\n", + mpam_partid_max + 1, mpam_pmg_max + 1); } =20 void mpam_disable(struct work_struct *ignored) @@ -745,4 +890,5 @@ static int __init mpam_msc_driver_init(void) =20 return platform_driver_register(&mpam_msc_driver); } +/* Must occur after arm64_mpam_register_cpus() from arch_initcall() */ subsys_initcall(mpam_msc_driver_init); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 8865a7d81dd1..9c08502e9c76 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -51,6 +51,8 @@ struct mpam_msc { */ struct mutex probe_lock; bool probed; + u16 partid_max; + u8 pmg_max; unsigned long ris_idxs; u32 ris_max; =20 @@ -140,6 +142,10 @@ struct mpam_msc_ris { extern struct srcu_struct mpam_srcu; extern struct list_head mpam_classes; =20 +/* System wide partid/pmg values */ +extern u16 mpam_partid_max; +extern u8 mpam_pmg_max; + /* Scheduled work callback to enable mpam once all MSC have been probed */ void mpam_enable(struct work_struct *work); void mpam_disable(struct work_struct *work); diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h index 3206f5ddc147..cb6e6cfbea0b 100644 --- a/include/linux/arm_mpam.h +++ b/include/linux/arm_mpam.h @@ -41,4 +41,18 @@ static inline int acpi_mpam_count_msc(void) { return -EI= NVAL; } int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx, enum mpam_class_types type, u8 class_id, int component_id); =20 +/** + * mpam_register_requestor() - Register a requestor with the MPAM driver + * @partid_max: The maximum PARTID value the requestor can generate. + * @pmg_max: The maximum PMG value the requestor can generate. + * + * Registers a requestor with the MPAM driver to ensure the chosen system-= wide + * minimum PARTID and PMG values will allow the requestors features to be = used. + * + * Returns an error if the registration is too late, and a larger PARTID/P= MG + * value has been advertised to user-space. In this case the requestor sho= uld + * not use its MPAM features. Returns 0 on success. + */ +int mpam_register_requestor(u16 partid_max, u8 pmg_max); + #endif /* __LINUX_ARM_MPAM_H */ --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EF0463370F8; Fri, 17 Oct 2025 18:58:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727491; cv=none; b=tiizYbZp/LU7vKdWjI+uoThEttd+Yz47ZEBWFsjbRE61uwJcQnAMrRDU4xwLZzV/BbZ3h7PhHuhrc5JD+k1ATRVfJnfbEXg/x8+uEiJsw6VT7cYuOO3nYc00MraONuFLsDkQicWaKfbjQWoFDdpBl2z4nEq0iJcEK3HTW15CKpU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727491; c=relaxed/simple; bh=G3SsLhxFI8p5Sv28fYljHJwRqTt/yt+C4b75QW23cJc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=U7mFxogv2tWbkgUSwNIHtjnKDw5fMyE04F+Zc+Oxs9pfui/25Cp5tPYbVXJsw/6eUY5EnzZPC6I6JJXPzbQyq4fa5Kew//2Xz6aHFdPjHyvqIoOy3Z02dk5XtUQvGi6OhoCkKr7NZZ2I1EZpn3xqruKp/bteFuLF+CmUFVjC99I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AEEEE1596; Fri, 17 Oct 2025 11:58:01 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ABA8B3F66E; Fri, 17 Oct 2025 11:58:04 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 12/29] arm_mpam: Add helpers for managing the locking around the mon_sel registers Date: Fri, 17 Oct 2025 18:56:28 +0000 Message-Id: <20251017185645.26604-13-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The MSC MON_SEL register needs to be accessed from hardirq for the overflow interrupt, and when taking an IPI to access these registers on platforms where MSC are not accessible from every CPU. This makes an irqsave spinlock the obvious lock to protect these registers. On systems with SCMI or PCC mailboxes it must be able to sleep, meaning a mutex must be used. The SCMI or PCC platforms can't support an overflow interrupt, and can't access the registers from hardirq context. Clearly these two can't exist for one MSC at the same time. Add helpers for the MON_SEL locking. For now, use a irqsave spinlock and only support 'real' MMIO platforms. In the future this lock will be split in two allowing SCMI/PCC platforms to take a mutex. Because there are contexts where the SCMI/PCC platforms can't make an access, mpam_mon_sel_lock() needs to be able to fail. Do this now, so that all the error handling on these paths is present. This allows the relevant paths to fail if they are needed on a platform where this isn't possible, instead of having to make explicit checks of the interface type. Tested-by: Fenghua Yu Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Tested-by: Peter Newman --- Change since v1: * Made accesses to outer_lock_held READ_ONCE() for torn values in the fail= ure case. --- drivers/resctrl/mpam_devices.c | 3 ++- drivers/resctrl/mpam_internal.h | 38 +++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 910bb6cd5e4f..35011d3e8f1e 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -738,6 +738,7 @@ static struct mpam_msc *do_mpam_msc_drv_probe(struct pl= atform_device *pdev) =20 mutex_init(&msc->probe_lock); mutex_init(&msc->part_sel_lock); + mpam_mon_sel_lock_init(msc); msc->id =3D pdev->id; msc->pdev =3D pdev; INIT_LIST_HEAD_RCU(&msc->all_msc_list); @@ -822,7 +823,7 @@ static void mpam_enable_once(void) "mpam:online"); =20 /* Use printk() to avoid the pr_fmt adding the function name. */ - printk(KERN_INFO, "MPAM enabled with %u PARTIDs and %u PMGs\n", + printk(KERN_INFO "MPAM enabled with %u PARTIDs and %u PMGs\n", mpam_partid_max + 1, mpam_pmg_max + 1); } =20 diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 9c08502e9c76..1afc52b36328 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -67,12 +67,50 @@ struct mpam_msc { */ struct mutex part_sel_lock; =20 + /* + * mon_sel_lock protects access to the MSC hardware registers that are + * affected by MPAMCFG_MON_SEL, and the mbwu_state. + * Access to mon_sel is needed from both process and interrupt contexts, + * but is complicated by firmware-backed platforms that can't make any + * access unless they can sleep. + * Always use the mpam_mon_sel_lock() helpers. + * Accesses to mon_sel need to be able to fail if they occur in the wrong + * context. + * If needed, take msc->probe_lock first. + */ + raw_spinlock_t _mon_sel_lock; + unsigned long _mon_sel_flags; + void __iomem *mapped_hwpage; size_t mapped_hwpage_sz; =20 struct mpam_garbage garbage; }; =20 +/* Returning false here means accesses to mon_sel must fail and report an = error. */ +static inline bool __must_check mpam_mon_sel_lock(struct mpam_msc *msc) +{ + WARN_ON_ONCE(msc->iface !=3D MPAM_IFACE_MMIO); + + raw_spin_lock_irqsave(&msc->_mon_sel_lock, msc->_mon_sel_flags); + return true; +} + +static inline void mpam_mon_sel_unlock(struct mpam_msc *msc) +{ + raw_spin_unlock_irqrestore(&msc->_mon_sel_lock, msc->_mon_sel_flags); +} + +static inline void mpam_mon_sel_lock_held(struct mpam_msc *msc) +{ + lockdep_assert_held_once(&msc->_mon_sel_lock); +} + +static inline void mpam_mon_sel_lock_init(struct mpam_msc *msc) +{ + raw_spin_lock_init(&msc->_mon_sel_lock); +} + struct mpam_class { /* mpam_components in this class */ struct list_head components; --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A654C332EA4; Fri, 17 Oct 2025 18:58:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727501; cv=none; b=QtAHSqbD0zxGdzN6sdnPprt7nd7Ryjo+/e4fMuq29LZHFlCXKebYojNSSl1EP9TRl0XWU+Kd0lYJeTGS0B03aUEPdTCQFlCXx/ATtrwnIUNGUDJO8KUJyWGX0lYlFah3jFa+aKqdWeWGFOvBIBh44S7sHqVKBvBCKnZui/Re14U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727501; c=relaxed/simple; bh=42uw3ey5VCJc8LKjYSjfS3DrIa+6urnzM1+GLaTi06o=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=K1yvhHj+or+21eBve72uqR2zzHsZk9M1qmQBMcTK1T6fmOktsDDC0nvt6oUr8N4Kxf/p+k403G7DwPMnsPArFXh8fkEHBljzb15vPzLem0bWzOH88VFVvtu+iYv+f3ssyC7R17YXO1k7bAtbWzPutiGxdcaUiPtRiQvHf9t5Gcs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1F7441C25; Fri, 17 Oct 2025 11:58:07 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E34E13F66E; Fri, 17 Oct 2025 11:58:09 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Dave Martin Subject: [PATCH v3 13/29] arm_mpam: Probe the hardware features resctrl supports Date: Fri, 17 Oct 2025 18:56:29 +0000 Message-Id: <20251017185645.26604-14-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Expand the probing support with the control and monitor types we can use with resctrl. CC: Dave Martin Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Moved some feature enum values that resctrl doesn't support to a later patch. * Swapped mpam_has_feature() out for the macro version that is used later. Changes since v1: * added an underscore to a variable name. Changes since RFC: * Made mpam_ris_hw_probe_hw_nrdy() more in C. * Added static assert on features bitmap size. --- drivers/resctrl/mpam_devices.c | 147 ++++++++++++++++++++++++++++++++ drivers/resctrl/mpam_internal.h | 33 +++++++ 2 files changed, 180 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 35011d3e8f1e..80c27c84dccc 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -142,6 +142,20 @@ static inline void _mpam_write_partsel_reg(struct mpam= _msc *msc, u16 reg, u32 va } #define mpam_write_partsel_reg(msc, reg, val) _mpam_write_partsel_reg(msc= , MPAMCFG_##reg, val) =20 +static inline u32 _mpam_read_monsel_reg(struct mpam_msc *msc, u16 reg) +{ + mpam_mon_sel_lock_held(msc); + return __mpam_read_reg(msc, reg); +} +#define mpam_read_monsel_reg(msc, reg) _mpam_read_monsel_reg(msc, MSMON_##= reg) + +static inline void _mpam_write_monsel_reg(struct mpam_msc *msc, u16 reg, u= 32 val) +{ + mpam_mon_sel_lock_held(msc); + __mpam_write_reg(msc, reg, val); +} +#define mpam_write_monsel_reg(msc, reg, val) _mpam_write_monsel_reg(msc,= MSMON_##reg, val) + static u64 mpam_msc_read_idr(struct mpam_msc *msc) { u64 idr_high =3D 0, idr_low; @@ -544,6 +558,133 @@ static struct mpam_msc_ris *mpam_get_or_create_ris(st= ruct mpam_msc *msc, return ERR_PTR(-ENOENT); } =20 +/* + * IHI009A.a has this nugget: "If a monitor does not support automatic beh= aviour + * of NRDY, software can use this bit for any purpose" - so hardware might= not + * implement this - but it isn't RES0. + * + * Try and see what values stick in this bit. If we can write either value, + * its probably not implemented by hardware. + */ +static bool _mpam_ris_hw_probe_hw_nrdy(struct mpam_msc_ris *ris, u32 mon_r= eg) +{ + u32 now; + u64 mon_sel; + bool can_set, can_clear; + struct mpam_msc *msc =3D ris->vmsc->msc; + + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + return false; + + mon_sel =3D FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, 0) | + FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); + _mpam_write_monsel_reg(msc, mon_reg, mon_sel); + + _mpam_write_monsel_reg(msc, mon_reg, MSMON___NRDY); + now =3D _mpam_read_monsel_reg(msc, mon_reg); + can_set =3D now & MSMON___NRDY; + + _mpam_write_monsel_reg(msc, mon_reg, 0); + now =3D _mpam_read_monsel_reg(msc, mon_reg); + can_clear =3D !(now & MSMON___NRDY); + mpam_mon_sel_unlock(msc); + + return (!can_set || !can_clear); +} + +#define mpam_ris_hw_probe_hw_nrdy(_ris, _mon_reg) \ + _mpam_ris_hw_probe_hw_nrdy(_ris, MSMON_##_mon_reg) + +static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) +{ + int err; + struct mpam_msc *msc =3D ris->vmsc->msc; + struct device *dev =3D &msc->pdev->dev; + struct mpam_props *props =3D &ris->props; + + lockdep_assert_held(&msc->probe_lock); + lockdep_assert_held(&msc->part_sel_lock); + + /* Cache Portion partitioning */ + if (FIELD_GET(MPAMF_IDR_HAS_CPOR_PART, ris->idr)) { + u32 cpor_features =3D mpam_read_partsel_reg(msc, CPOR_IDR); + + props->cpbm_wd =3D FIELD_GET(MPAMF_CPOR_IDR_CPBM_WD, cpor_features); + if (props->cpbm_wd) + mpam_set_feature(mpam_feat_cpor_part, props); + } + + /* Memory bandwidth partitioning */ + if (FIELD_GET(MPAMF_IDR_HAS_MBW_PART, ris->idr)) { + u32 mbw_features =3D mpam_read_partsel_reg(msc, MBW_IDR); + + /* portion bitmap resolution */ + props->mbw_pbm_bits =3D FIELD_GET(MPAMF_MBW_IDR_BWPBM_WD, mbw_features); + if (props->mbw_pbm_bits && + FIELD_GET(MPAMF_MBW_IDR_HAS_PBM, mbw_features)) + mpam_set_feature(mpam_feat_mbw_part, props); + + props->bwa_wd =3D FIELD_GET(MPAMF_MBW_IDR_BWA_WD, mbw_features); + if (props->bwa_wd && FIELD_GET(MPAMF_MBW_IDR_HAS_MAX, mbw_features)) + mpam_set_feature(mpam_feat_mbw_max, props); + } + + /* Performance Monitoring */ + if (FIELD_GET(MPAMF_IDR_HAS_MSMON, ris->idr)) { + u32 msmon_features =3D mpam_read_partsel_reg(msc, MSMON_IDR); + + /* + * If the firmware max-nrdy-us property is missing, the + * CSU counters can't be used. Should we wait forever? + */ + err =3D device_property_read_u32(&msc->pdev->dev, + "arm,not-ready-us", + &msc->nrdy_usec); + + if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_CSU, msmon_features)) { + u32 csumonidr; + + csumonidr =3D mpam_read_partsel_reg(msc, CSUMON_IDR); + props->num_csu_mon =3D FIELD_GET(MPAMF_CSUMON_IDR_NUM_MON, csumonidr); + if (props->num_csu_mon) { + bool hw_managed; + + mpam_set_feature(mpam_feat_msmon_csu, props); + + /* Is NRDY hardware managed? */ + hw_managed =3D mpam_ris_hw_probe_hw_nrdy(ris, CSU); + if (hw_managed) + mpam_set_feature(mpam_feat_msmon_csu_hw_nrdy, props); + } + + /* + * Accept the missing firmware property if NRDY appears + * un-implemented. + */ + if (err && mpam_has_feature(mpam_feat_msmon_csu_hw_nrdy, props)) + dev_err_once(dev, "Counters are not usable because not-ready timeout w= as not provided by firmware."); + } + if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_MBWU, msmon_features)) { + bool hw_managed; + u32 mbwumon_idr =3D mpam_read_partsel_reg(msc, MBWUMON_IDR); + + props->num_mbwu_mon =3D FIELD_GET(MPAMF_MBWUMON_IDR_NUM_MON, mbwumon_id= r); + if (props->num_mbwu_mon) + mpam_set_feature(mpam_feat_msmon_mbwu, props); + + /* Is NRDY hardware managed? */ + hw_managed =3D mpam_ris_hw_probe_hw_nrdy(ris, MBWU); + if (hw_managed) + mpam_set_feature(mpam_feat_msmon_mbwu_hw_nrdy, props); + + /* + * Don't warn about any missing firmware property for + * MBWU NRDY - it doesn't make any sense! + */ + } + } +} + static int mpam_msc_hw_probe(struct mpam_msc *msc) { u64 idr; @@ -587,6 +728,12 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) mutex_unlock(&mpam_list_lock); if (IS_ERR(ris)) return PTR_ERR(ris); + ris->idr =3D idr; + + mutex_lock(&msc->part_sel_lock); + __mpam_part_sel(ris_idx, 0, msc); + mpam_ris_hw_probe(ris); + mutex_unlock(&msc->part_sel_lock); } =20 spin_lock(&partid_max_lock); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 1afc52b36328..be9ea0aab6d2 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -5,6 +5,7 @@ #define MPAM_INTERNAL_H =20 #include +#include #include #include #include @@ -13,6 +14,7 @@ #include #include #include +#include =20 #define MPAM_MSC_MAX_NUM_RIS 16 =20 @@ -111,6 +113,33 @@ static inline void mpam_mon_sel_lock_init(struct mpam_= msc *msc) raw_spin_lock_init(&msc->_mon_sel_lock); } =20 +/* Bits for mpam features bitmaps */ +enum mpam_device_features { + mpam_feat_cpor_part =3D 0, + mpam_feat_mbw_part, + mpam_feat_mbw_min, + mpam_feat_mbw_max, + mpam_feat_msmon, + mpam_feat_msmon_csu, + mpam_feat_msmon_csu_hw_nrdy, + mpam_feat_msmon_mbwu, + mpam_feat_msmon_mbwu_hw_nrdy, + MPAM_FEATURE_LAST +}; + +struct mpam_props { + DECLARE_BITMAP(features, MPAM_FEATURE_LAST); + + u16 cpbm_wd; + u16 mbw_pbm_bits; + u16 bwa_wd; + u16 num_csu_mon; + u16 num_mbwu_mon; +}; + +#define mpam_has_feature(_feat, x) test_bit(_feat, (x)->features) +#define mpam_set_feature(_feat, x) set_bit(_feat, (x)->features) + struct mpam_class { /* mpam_components in this class */ struct list_head components; @@ -150,6 +179,8 @@ struct mpam_vmsc { /* mpam_msc_ris in this vmsc */ struct list_head ris; =20 + struct mpam_props props; + /* All RIS in this vMSC are members of this MSC */ struct mpam_msc *msc; =20 @@ -161,6 +192,8 @@ struct mpam_vmsc { =20 struct mpam_msc_ris { u8 ris_idx; + u64 idr; + struct mpam_props props; =20 cpumask_t affinity; =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DEE4F335070; Fri, 17 Oct 2025 18:58:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727503; cv=none; b=eaZytYo4/xtCtjupY+ku1ZXbP1FDq7NpLVxWS+xRmejMZ98UdprnK8qvGU82BsYL0/lP5An8IAckMNbmHKlAqt6ErdsWuqoAL3RJYPSOUhO/m54Lw2Nrbxtc+WFL8ePJrLc8EmNbEPjsybRYG2bm/RP5dcf0FfRcVYGeQ7Uqwqc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727503; c=relaxed/simple; bh=sshFD+WvOWTRooA+GmREDFefgDALSgwyFiOEVp2TfjM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=uGw85zYEJax8qbZLD9h6P15lOZoCFj7dwZk4HJc5ogoDBW7aMlIIbei3TBg8ezF9mE5N8AQXd+UousMyj7XMbBMdUPQqN/W/IRkOszpivXW2sHHEfn5PYc1RDuYRdk+usCiYPmEy7rk7j7RztrMDMy1mLA87Do4Lfy46uYzK0VU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8C38F1515; Fri, 17 Oct 2025 11:58:12 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 57A1A3F66E; Fri, 17 Oct 2025 11:58:15 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 14/29] arm_mpam: Merge supported features during mpam_enable() into mpam_class Date: Fri, 17 Oct 2025 18:56:30 +0000 Message-Id: <20251017185645.26604-15-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" To make a decision about whether to expose an mpam class as a resctrl resource we need to know its overall supported features and properties. Once we've probed all the resources, we can walk the tree and produce overall values by merging the bitmaps. This eliminates features that are only supported by some MSC that make up a component or class. If bitmap properties are mismatched within a component we cannot support the mismatched feature. Care has to be taken as vMSC may hold mismatched RIS. Signed-off-by: James Morse Reviewed-by: Ben Horgan Reviewed-by: Jonathan Cameron Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Removed __func_ from pr_debug messages, pr_fmt has this covered. * Made a few debug messages used dev_dvg. * Dropped paranoia around empty vmsc/component lists. * Reworded comment describing the feature merging to state why the order matters and which helpers do what. --- drivers/resctrl/mpam_devices.c | 214 ++++++++++++++++++++++++++++++++ drivers/resctrl/mpam_internal.h | 3 + 2 files changed, 217 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 80c27c84dccc..e150f4a0bfcd 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -956,8 +956,222 @@ static struct platform_driver mpam_msc_driver =3D { .remove =3D mpam_msc_drv_remove, }; =20 +/* Any of these features mean the BWA_WD field is valid. */ +static bool mpam_has_bwa_wd_feature(struct mpam_props *props) +{ + if (mpam_has_feature(mpam_feat_mbw_min, props)) + return true; + if (mpam_has_feature(mpam_feat_mbw_max, props)) + return true; + return false; +} + +#define MISMATCHED_HELPER(parent, child, helper, field, alias) \ + helper(parent) && \ + ((helper(child) && (parent)->field !=3D (child)->field) || \ + (!helper(child) && !(alias))) + +#define MISMATCHED_FEAT(parent, child, feat, field, alias) \ + mpam_has_feature((feat), (parent)) && \ + ((mpam_has_feature((feat), (child)) && (parent)->field !=3D (child)->fiel= d) || \ + (!mpam_has_feature((feat), (child)) && !(alias))) + +#define CAN_MERGE_FEAT(parent, child, feat, alias) \ + (alias) && !mpam_has_feature((feat), (parent)) && \ + mpam_has_feature((feat), (child)) + +/* + * Combine two props fields. + * If this is for controls that alias the same resource, it is safe to just + * copy the values over. If two aliasing controls implement the same scheme + * a safe value must be picked. + * For non-aliasing controls, these control different resources, and the + * resulting safe value must be compatible with both. When merging values = in + * the tree, all the aliasing resources must be handled first. + * On mismatch, parent is modified. + */ +static void __props_mismatch(struct mpam_props *parent, + struct mpam_props *child, bool alias) +{ + if (CAN_MERGE_FEAT(parent, child, mpam_feat_cpor_part, alias)) { + parent->cpbm_wd =3D child->cpbm_wd; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_cpor_part, + cpbm_wd, alias)) { + pr_debug("cleared cpor_part\n"); + mpam_clear_feature(mpam_feat_cpor_part, parent); + parent->cpbm_wd =3D 0; + } + + if (CAN_MERGE_FEAT(parent, child, mpam_feat_mbw_part, alias)) { + parent->mbw_pbm_bits =3D child->mbw_pbm_bits; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_mbw_part, + mbw_pbm_bits, alias)) { + pr_debug("cleared mbw_part\n"); + mpam_clear_feature(mpam_feat_mbw_part, parent); + parent->mbw_pbm_bits =3D 0; + } + + /* bwa_wd is a count of bits, fewer bits means less precision */ + if (alias && !mpam_has_bwa_wd_feature(parent) && + mpam_has_bwa_wd_feature(child)) { + parent->bwa_wd =3D child->bwa_wd; + } else if (MISMATCHED_HELPER(parent, child, mpam_has_bwa_wd_feature, + bwa_wd, alias)) { + pr_debug("took the min bwa_wd\n"); + parent->bwa_wd =3D min(parent->bwa_wd, child->bwa_wd); + } + + /* For num properties, take the minimum */ + if (CAN_MERGE_FEAT(parent, child, mpam_feat_msmon_csu, alias)) { + parent->num_csu_mon =3D child->num_csu_mon; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_msmon_csu, + num_csu_mon, alias)) { + pr_debug("took the min num_csu_mon\n"); + parent->num_csu_mon =3D min(parent->num_csu_mon, + child->num_csu_mon); + } + + if (CAN_MERGE_FEAT(parent, child, mpam_feat_msmon_mbwu, alias)) { + parent->num_mbwu_mon =3D child->num_mbwu_mon; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_msmon_mbwu, + num_mbwu_mon, alias)) { + pr_debug("took the min num_mbwu_mon\n"); + parent->num_mbwu_mon =3D min(parent->num_mbwu_mon, + child->num_mbwu_mon); + } + + if (alias) { + /* Merge features for aliased resources */ + bitmap_or(parent->features, parent->features, child->features, MPAM_FEAT= URE_LAST); + } else { + /* Clear missing features for non aliasing */ + bitmap_and(parent->features, parent->features, child->features, MPAM_FEA= TURE_LAST); + } +} + +/* + * If a vmsc doesn't match class feature/configuration, do the right thing= (tm). + * For 'num' properties we can just take the minimum. + * For properties where the mismatched unused bits would make a difference= , we + * nobble the class feature, as we can't configure all the resources. + * e.g. The L3 cache is composed of two resources with 13 and 17 portion + * bitmaps respectively. + */ +static void +__class_props_mismatch(struct mpam_class *class, struct mpam_vmsc *vmsc) +{ + struct mpam_props *cprops =3D &class->props; + struct mpam_props *vprops =3D &vmsc->props; + struct device *dev =3D &vmsc->msc->pdev->dev; + + lockdep_assert_held(&mpam_list_lock); /* we modify class */ + + dev_dbg(dev, "Merging features for class:0x%lx &=3D vmsc:0x%lx\n", + (long)cprops->features, (long)vprops->features); + + /* Take the safe value for any common features */ + __props_mismatch(cprops, vprops, false); +} + +static void +__vmsc_props_mismatch(struct mpam_vmsc *vmsc, struct mpam_msc_ris *ris) +{ + struct mpam_props *rprops =3D &ris->props; + struct mpam_props *vprops =3D &vmsc->props; + struct device *dev =3D &vmsc->msc->pdev->dev; + + lockdep_assert_held(&mpam_list_lock); /* we modify vmsc */ + + dev_dbg(dev, "Merging features for vmsc:0x%lx |=3D ris:0x%lx\n", + (long)vprops->features, (long)rprops->features); + + /* + * Merge mismatched features - Copy any features that aren't common, + * but take the safe value for any common features. + */ + __props_mismatch(vprops, rprops, true); +} + +/* + * Copy the first component's first vMSC's properties and features to the + * class. __class_props_mismatch() will remove conflicts. + * It is not possible to have a class with no components, or a component w= ith + * no resources. The vMSC properties have already been built. + */ +static void mpam_enable_init_class_features(struct mpam_class *class) +{ + struct mpam_vmsc *vmsc; + struct mpam_component *comp; + + comp =3D list_first_entry(&class->components, + struct mpam_component, class_list); + vmsc =3D list_first_entry(&comp->vmsc, + struct mpam_vmsc, comp_list); + + class->props =3D vmsc->props; +} + +static void mpam_enable_merge_vmsc_features(struct mpam_component *comp) +{ + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + struct mpam_class *class =3D comp->class; + + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + list_for_each_entry(ris, &vmsc->ris, vmsc_list) { + __vmsc_props_mismatch(vmsc, ris); + class->nrdy_usec =3D max(class->nrdy_usec, + vmsc->msc->nrdy_usec); + } + } +} + +static void mpam_enable_merge_class_features(struct mpam_component *comp) +{ + struct mpam_vmsc *vmsc; + struct mpam_class *class =3D comp->class; + + list_for_each_entry(vmsc, &comp->vmsc, comp_list) + __class_props_mismatch(class, vmsc); +} + +/* + * Merge all the common resource features into class. + * vmsc features are bitwise-or'd together by mpam_enable_merge_vmsc_featu= res() + * as the first step so that mpam_enable_init_class_features() can initial= ise + * the class with a representive set of features. + * Next the mpam_enable_merge_class_features() bitwise-and's all the vmsc + * features to form the class features. + * Other features are the min/max as appropriate. + * + * To avoid walking the whole tree twice, the class->nrdy_usec property is + * updated when working with the vmsc as it is a max(), and doesn't need + * initialising first. + */ +static void mpam_enable_merge_features(struct list_head *all_classes_list) +{ + struct mpam_class *class; + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(class, all_classes_list, classes_list) { + list_for_each_entry(comp, &class->components, class_list) + mpam_enable_merge_vmsc_features(comp); + + mpam_enable_init_class_features(class); + + list_for_each_entry(comp, &class->components, class_list) + mpam_enable_merge_class_features(comp); + } +} + static void mpam_enable_once(void) { + mutex_lock(&mpam_list_lock); + mpam_enable_merge_features(&mpam_classes); + mutex_unlock(&mpam_list_lock); + /* * Once the cpuhp callbacks have been changed, mpam_partid_max can no * longer change. diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index be9ea0aab6d2..39331d81c481 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -139,6 +139,7 @@ struct mpam_props { =20 #define mpam_has_feature(_feat, x) test_bit(_feat, (x)->features) #define mpam_set_feature(_feat, x) set_bit(_feat, (x)->features) +#define mpam_clear_feature(_feat, x) clear_bit(_feat, (x)->features) =20 struct mpam_class { /* mpam_components in this class */ @@ -146,6 +147,8 @@ struct mpam_class { =20 cpumask_t affinity; =20 + struct mpam_props props; + u32 nrdy_usec; u8 level; enum mpam_class_types type; =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 82F2336996C; Fri, 17 Oct 2025 18:58:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727508; cv=none; b=MRgZ0XOuvp8rIQxE7jH8kwER7TrlX3W5shL12v2EpaoSsBbQDZ24sNclzoVBL3ShlV8wmb2kz33BFQWCFUs1M01LsVtGah6iVIgU9s9u1epM/5myLsX0uTlTLNOYqvhOlzAHgk/hqEn19i6xQgap7PQq8n60sXdqkrbNPFsfn2Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727508; c=relaxed/simple; bh=1LmMMFJZCMFFgQwuJr5YmKfEtqzSGD2GBWsLqPjVwho=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=YkSWK7jJRooymOz7+8dM91P++XtPKmGXJ1PqPPxsF/prQ2c5DXAD++3FVsJGTGXU9HafHf9yRXkERouJDxDnOBUOfZmXxkZbwYY65dusQDOoTfExCcdJtH/Ri3y4Rf/xw8Zx1czmeR01ugAF2gXhhTBxPJRKQsLR5FzBMdOI+6U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 070241515; Fri, 17 Oct 2025 11:58:18 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C2D523F66E; Fri, 17 Oct 2025 11:58:20 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Rohit Mathew Subject: [PATCH v3 15/29] arm_mpam: Reset MSC controls from cpuhp callbacks Date: Fri, 17 Oct 2025 18:56:31 +0000 Message-Id: <20251017185645.26604-16-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When a CPU comes online, it may bring a newly accessible MSC with it. Only the default partid has its value reset by hardware, and even then the MSC might not have been reset since its config was previously dirtied. e.g. Kexec. Any in-use partid must have its configuration restored, or reset. In-use partids may be held in caches and evicted later. MSC are also reset when CPUs are taken offline to cover cases where firmware doesn't reset the MSC over reboot using UEFI, or kexec where there is no firmware involvement. If the configuration for a RIS has not been touched since it was brought online, it does not need resetting again. To reset, write the maximum values for all discovered controls. CC: Rohit Mathew Signed-off-by: James Morse Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Reviewed-by: Jonathan Cameron Tested-by: Peter Newman --- Changes since v2: * Dropped srcu lockdep assert, the list_for_each helper has this covered. * removed a space from the patch subject * use guard lock/unlock for srcu in online/offline calls. * Remove mpam_assert_srcu_read_lock_held() and drop usage next to the list walker. * Fixed off by one in mpam_reset_ris() Changes since RFC: * Last bitmap write will always be non-zero. * Dropped READ_ONCE() - the value can no longer change. * Write 0 to proporitional stride, remove the bwa_fract variable. * Removed nested srcu lock, the assert should cover it. --- drivers/resctrl/mpam_devices.c | 109 ++++++++++++++++++++++++++++++++ drivers/resctrl/mpam_internal.h | 3 + 2 files changed, 112 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index e150f4a0bfcd..02709b4ae9d4 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -746,8 +747,104 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) return 0; } =20 +static void mpam_reset_msc_bitmap(struct mpam_msc *msc, u16 reg, u16 wd) +{ + u32 num_words, msb; + u32 bm =3D ~0; + int i; + + lockdep_assert_held(&msc->part_sel_lock); + + if (wd =3D=3D 0) + return; + + /* + * Write all ~0 to all but the last 32bit-word, which may + * have fewer bits... + */ + num_words =3D DIV_ROUND_UP(wd, 32); + for (i =3D 0; i < num_words - 1; i++, reg +=3D sizeof(bm)) + __mpam_write_reg(msc, reg, bm); + + /* + * ....and then the last (maybe) partial 32bit word. When wd is a + * multiple of 32, msb should be 31 to write a full 32bit word. + */ + msb =3D (wd - 1) % 32; + bm =3D GENMASK(msb, 0); + __mpam_write_reg(msc, reg, bm); +} + +static void mpam_reset_ris_partid(struct mpam_msc_ris *ris, u16 partid) +{ + struct mpam_msc *msc =3D ris->vmsc->msc; + struct mpam_props *rprops =3D &ris->props; + + WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu))); + + mutex_lock(&msc->part_sel_lock); + __mpam_part_sel(ris->ris_idx, partid, msc); + + if (mpam_has_feature(mpam_feat_cpor_part, rprops)) + mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, rprops->cpbm_wd); + + if (mpam_has_feature(mpam_feat_mbw_part, rprops)) + mpam_reset_msc_bitmap(msc, MPAMCFG_MBW_PBM, rprops->mbw_pbm_bits); + + if (mpam_has_feature(mpam_feat_mbw_min, rprops)) + mpam_write_partsel_reg(msc, MBW_MIN, 0); + + if (mpam_has_feature(mpam_feat_mbw_max, rprops)) + mpam_write_partsel_reg(msc, MBW_MAX, MPAMCFG_MBW_MAX_MAX); + + mutex_unlock(&msc->part_sel_lock); +} + +static void mpam_reset_ris(struct mpam_msc_ris *ris) +{ + u16 partid, partid_max; + + WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu))); + + if (ris->in_reset_state) + return; + + spin_lock(&partid_max_lock); + partid_max =3D mpam_partid_max; + spin_unlock(&partid_max_lock); + for (partid =3D 0; partid < partid_max + 1; partid++) + mpam_reset_ris_partid(ris, partid); +} + +static void mpam_reset_msc(struct mpam_msc *msc, bool online) +{ + struct mpam_msc_ris *ris; + + list_for_each_entry_srcu(ris, &msc->ris, msc_list, srcu_read_lock_held(&m= pam_srcu)) { + mpam_reset_ris(ris); + + /* + * Set in_reset_state when coming online. The reset state + * for non-zero partid may be lost while the CPUs are offline. + */ + ris->in_reset_state =3D online; + } +} + static int mpam_cpu_online(unsigned int cpu) { + struct mpam_msc *msc; + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!cpumask_test_cpu(cpu, &msc->accessibility)) + continue; + + if (atomic_fetch_inc(&msc->online_refs) =3D=3D 0) + mpam_reset_msc(msc, true); + } + return 0; } =20 @@ -786,6 +883,18 @@ static int mpam_discovery_cpu_online(unsigned int cpu) =20 static int mpam_cpu_offline(unsigned int cpu) { + struct mpam_msc *msc; + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!cpumask_test_cpu(cpu, &msc->accessibility)) + continue; + + if (atomic_dec_and_test(&msc->online_refs)) + mpam_reset_msc(msc, false); + } + return 0; } =20 diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 39331d81c481..9f062dd5a0bb 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -5,6 +5,7 @@ #define MPAM_INTERNAL_H =20 #include +#include #include #include #include @@ -46,6 +47,7 @@ struct mpam_msc { enum mpam_msc_iface iface; u32 nrdy_usec; cpumask_t accessibility; + atomic_t online_refs; =20 /* * probe_lock is only taken during discovery. After discovery these @@ -197,6 +199,7 @@ struct mpam_msc_ris { u8 ris_idx; u64 idr; struct mpam_props props; + bool in_reset_state; =20 cpumask_t affinity; =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0D11F36996C; Fri, 17 Oct 2025 18:58:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727513; cv=none; b=otw2AHj1nvLKYVk5M5sNq9ctbmH9UfSGJAOSEC8HptiHvx8tIc3hfxr3v38XUHvFeL+UkodSybh6OUQAnPu+GYRawXmRYecvWY+70AMu5aLjgNeqBh1DMp8dHxF3zH9lajL0TDmrrTA/quQE4Ug+0daqjzkhxMj00WTLRsc4PDQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727513; c=relaxed/simple; bh=631pSZKrhzjBH8HzzPO5wbm8noF/74larY2Fm9NkEQU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=N2ERZzDxz2O3uXD+USbddjZ9VKnW5nnF3sbsEDgPVBeQmrTtb6TnJtk6JeoNCbyXeqJ2buD/uYCjg7TGMHSqe3E/BPZH964GWawrJkpfw6leLUKRIISi++f7mPIhz6deCBynbo6nYIJdcZ2eLaOByQbEEXYpvH9RHBCJdrESwSk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 666161515; Fri, 17 Oct 2025 11:58:23 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3D43A3F66E; Fri, 17 Oct 2025 11:58:26 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 16/29] arm_mpam: Add a helper to touch an MSC from any CPU Date: Fri, 17 Oct 2025 18:56:32 +0000 Message-Id: <20251017185645.26604-17-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Resetting RIS entries from the cpuhp callback is easy as the callback occurs on the correct CPU. This won't be true for any other caller that wants to reset or configure an MSC. Add a helper that schedules the provided function if necessary. Callers should take the cpuhp lock to prevent the cpuhp callbacks from changing the MSC state. Signed-off-by: James Morse Reviewed-by: Ben Horgan Reviewed-by: Jonathan Cameron Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- drivers/resctrl/mpam_devices.c | 37 +++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 02709b4ae9d4..ec089593acad 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -800,20 +800,51 @@ static void mpam_reset_ris_partid(struct mpam_msc_ris= *ris, u16 partid) mutex_unlock(&msc->part_sel_lock); } =20 -static void mpam_reset_ris(struct mpam_msc_ris *ris) +/* + * Called via smp_call_on_cpu() to prevent migration, while still being + * pre-emptible. + */ +static int mpam_reset_ris(void *arg) { u16 partid, partid_max; + struct mpam_msc_ris *ris =3D arg; =20 WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu))); =20 if (ris->in_reset_state) - return; + return 0; =20 spin_lock(&partid_max_lock); partid_max =3D mpam_partid_max; spin_unlock(&partid_max_lock); for (partid =3D 0; partid < partid_max + 1; partid++) mpam_reset_ris_partid(ris, partid); + + return 0; +} + +/* + * Get the preferred CPU for this MSC. If it is accessible from this CPU, + * this CPU is preferred. This can be preempted/migrated, it will only res= ult + * in more work. + */ +static int mpam_get_msc_preferred_cpu(struct mpam_msc *msc) +{ + int cpu =3D raw_smp_processor_id(); + + if (cpumask_test_cpu(cpu, &msc->accessibility)) + return cpu; + + return cpumask_first_and(&msc->accessibility, cpu_online_mask); +} + +static int mpam_touch_msc(struct mpam_msc *msc, int (*fn)(void *a), void *= arg) +{ + lockdep_assert_irqs_enabled(); + lockdep_assert_cpus_held(); + WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu))); + + return smp_call_on_cpu(mpam_get_msc_preferred_cpu(msc), fn, arg, true); } =20 static void mpam_reset_msc(struct mpam_msc *msc, bool online) @@ -821,7 +852,7 @@ static void mpam_reset_msc(struct mpam_msc *msc, bool o= nline) struct mpam_msc_ris *ris; =20 list_for_each_entry_srcu(ris, &msc->ris, msc_list, srcu_read_lock_held(&m= pam_srcu)) { - mpam_reset_ris(ris); + mpam_touch_msc(msc, &mpam_reset_ris, ris); =20 /* * Set in_reset_state when coming online. The reset state --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2524436CE03; Fri, 17 Oct 2025 18:58:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727518; cv=none; b=uov1eww+e+S91bFsojYjxKH565Xv6n4hadn8stbGqmLTowIH7/kTSSfzu1b6fMgm3KS0+teCaMV7h9V/EMyY24LZYD0CJ+vc2RxJoae7ISES0awOIfxtxaC+5HeOXgqnm0vW5p38irHANTeT32OeAGEWvYkGqXuW1ez57DNblfw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727518; c=relaxed/simple; bh=ZDnkddHVA67wGKnfxu2HrHojd6o4rL3MbPoUleD7ePY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Xmi60hvUnWsvAuyJQkYgnMzL8SvSHUxQIagD1PQOfAMVW6fBJcHi/4/TM9QHdG5GjN7yvlkp0Mr0/VbLfwoyD4ERfRiPHe9U20lh0l/m8jSiia9qkZq9DIlyOik5jW/WvNgMswRUCLh+rTXZ1CTbeiOJS1c/7XPqXaYClPFGWdQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CC03C1595; Fri, 17 Oct 2025 11:58:28 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9C9593F66E; Fri, 17 Oct 2025 11:58:31 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 17/29] arm_mpam: Extend reset logic to allow devices to be reset any time Date: Fri, 17 Oct 2025 18:56:33 +0000 Message-Id: <20251017185645.26604-18-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" cpuhp callbacks aren't the only time the MSC configuration may need to be reset. Resctrl has an API call to reset a class. If an MPAM error interrupt arrives it indicates the driver has misprogrammed an MSC. The safest thing to do is reset all the MSCs and disable MPAM. Add a helper to reset RIS via their class. Call this from mpam_disable(), which can be scheduled from the error interrupt handler. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Reduced the scop of arguments in mpam_reset_component_locked(). Changes since v1: * more complete use of _srcu helpers. * Use guard macro for srcu. * Dropped a might_sleep() - something else will bark. --- drivers/resctrl/mpam_devices.c | 58 ++++++++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 3 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index ec089593acad..545482e112b7 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -802,15 +802,13 @@ static void mpam_reset_ris_partid(struct mpam_msc_ris= *ris, u16 partid) =20 /* * Called via smp_call_on_cpu() to prevent migration, while still being - * pre-emptible. + * pre-emptible. Caller must hold mpam_srcu. */ static int mpam_reset_ris(void *arg) { u16 partid, partid_max; struct mpam_msc_ris *ris =3D arg; =20 - WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu))); - if (ris->in_reset_state) return 0; =20 @@ -1328,8 +1326,56 @@ static void mpam_enable_once(void) mpam_partid_max + 1, mpam_pmg_max + 1); } =20 +static void mpam_reset_component_locked(struct mpam_component *comp) +{ + + struct mpam_vmsc *vmsc; + + lockdep_assert_cpus_held(); + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list, + srcu_read_lock_held(&mpam_srcu)) { + struct mpam_msc *msc =3D vmsc->msc; + struct mpam_msc_ris *ris; + + list_for_each_entry_srcu(ris, &vmsc->ris, vmsc_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!ris->in_reset_state) + mpam_touch_msc(msc, mpam_reset_ris, ris); + ris->in_reset_state =3D true; + } + } +} + +static void mpam_reset_class_locked(struct mpam_class *class) +{ + struct mpam_component *comp; + + lockdep_assert_cpus_held(); + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(comp, &class->components, class_list, + srcu_read_lock_held(&mpam_srcu)) + mpam_reset_component_locked(comp); +} + +static void mpam_reset_class(struct mpam_class *class) +{ + cpus_read_lock(); + mpam_reset_class_locked(class); + cpus_read_unlock(); +} + +/* + * Called in response to an error IRQ. + * All of MPAMs errors indicate a software bug, restore any modified + * controls to their reset values. + */ void mpam_disable(struct work_struct *ignored) { + int idx; + struct mpam_class *class; struct mpam_msc *msc, *tmp; =20 mutex_lock(&mpam_cpuhp_state_lock); @@ -1339,6 +1385,12 @@ void mpam_disable(struct work_struct *ignored) } mutex_unlock(&mpam_cpuhp_state_lock); =20 + idx =3D srcu_read_lock(&mpam_srcu); + list_for_each_entry_srcu(class, &mpam_classes, classes_list, + srcu_read_lock_held(&mpam_srcu)) + mpam_reset_class(class); + srcu_read_unlock(&mpam_srcu, idx); + mutex_lock(&mpam_list_lock); list_for_each_entry_safe(msc, tmp, &mpam_all_msc, all_msc_list) mpam_msc_destroy(msc); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5523A332ED8; Fri, 17 Oct 2025 18:58:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727524; cv=none; b=A6miDymE9LpWwIbpxXPIXk0cTayRVa0SOBXQjGM8H/fvU64P8tK1JkHX26sJof3DvqQCda7dAevXE6igLb/8N6MwrFYrUSc+tToaD1rAv6zfe0iiw0H3RqX6od9Eti2rlPLd0paR7AfzaRgYRd/zSl3EhPCBZvOpz62C/ApIoeQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727524; c=relaxed/simple; bh=btQ8SOCcsEC8zRLBzswuS8RxBdJW9XO0n9yG0hUXXkQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LycVnLPiVXbNd+nibt/BSqp9965sDL5F068sSsEhh31mzyvxmgUx52Vt9YRggbEjdzSizyi/aDSDGurf20wStn6Yp6kkoQZywKBh1jwE1OBkr+UdmZFtrBrtLSLHgAXsnI3CKmCE6CtN7SVWJKKj1UqqzC3Yb1kCGPJxHtpALQg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 143881515; Fri, 17 Oct 2025 11:58:34 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0CC653F66E; Fri, 17 Oct 2025 11:58:36 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 18/29] arm_mpam: Register and enable IRQs Date: Fri, 17 Oct 2025 18:56:34 +0000 Message-Id: <20251017185645.26604-19-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Register and enable error IRQs. All the MPAM error interrupts indicate a software bug, e.g. out of range partid. If the error interrupt is ever signalled, attempt to disable MPAM. Only the irq handler accesses the MPAMF_ESR register, so no locking is needed. The work to disable MPAM after an error needs to happen at process context as it takes mutex. It also unregisters the interrupts, meaning it can't be done from the threaded part of a threaded interrupt. Instead, mpam_disable() gets scheduled. Enabling the IRQs in the MSC may involve cross calling to a CPU that can access the MSC. Once the IRQ is requested, the mpam_disable() path can be called asynchronously, which will walk structures sized by max_partid. Ensure this size is fixed before the interrupt is requested. CC: Rohit Mathew Tested-by: Rohit Mathew Tested-by: Fenghua Yu Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Tested-by: Peter Newman --- Changes since v2: * Assign mpam_errcode_names[] from their preprocessor defines. * Removed overlapping ppi case that can't happen without ppi partitions. * Renamed zero/clear. * Convert atomic bitmaps to use mutex and bools. * Added 'disable reason' for mpam_enable(). Changes since v1: * Made mpam_unregister_irqs() safe to race with itself. * Removed threaded interrupts. * Schedule mpam_disable() from cpuhp callback in the case of an error. * Added mpam_disable_reason. * Use alloc_percpu() Changes since RFC: * Use guard marco when walking srcu list. * Use INTEN macro for enabling interrupts. * Move partid_max_published up earlier in mpam_enable_once(). --- drivers/resctrl/mpam_devices.c | 283 +++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 13 ++ 2 files changed, 293 insertions(+), 3 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 545482e112b7..f18a22f825a0 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -14,6 +14,9 @@ #include #include #include +#include +#include +#include #include #include #include @@ -170,6 +173,34 @@ static u64 mpam_msc_read_idr(struct mpam_msc *msc) return (idr_high << 32) | idr_low; } =20 +static void mpam_msc_clear_esr(struct mpam_msc *msc) +{ + u64 esr_low =3D __mpam_read_reg(msc, MPAMF_ESR); + if (!esr_low) + return; + + /* + * Clearing the high/low bits of MPAMF_ESR can not be atomic. + * Clear the top half first, so that the pending error bits in the + * lower half prevent hardware from updating either half of the + * register. + */ + if (msc->has_extd_esr) + __mpam_write_reg(msc, MPAMF_ESR + 4, 0); + __mpam_write_reg(msc, MPAMF_ESR, 0); +} + +static u64 mpam_msc_read_esr(struct mpam_msc *msc) +{ + u64 esr_high =3D 0, esr_low; + + esr_low =3D __mpam_read_reg(msc, MPAMF_ESR); + if (msc->has_extd_esr) + esr_high =3D __mpam_read_reg(msc, MPAMF_ESR + 4); + + return (esr_high << 32) | esr_low; +} + static void __mpam_part_sel_raw(u32 partsel, struct mpam_msc *msc) { lockdep_assert_held(&msc->part_sel_lock); @@ -723,6 +754,7 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) pmg_max =3D FIELD_GET(MPAMF_IDR_PMG_MAX, idr); msc->partid_max =3D min(msc->partid_max, partid_max); msc->pmg_max =3D min(msc->pmg_max, pmg_max); + msc->has_extd_esr =3D FIELD_GET(MPAMF_IDR_HAS_EXTD_ESR, idr); =20 mutex_lock(&mpam_list_lock); ris =3D mpam_get_or_create_ris(msc, ris_idx); @@ -737,6 +769,9 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) mutex_unlock(&msc->part_sel_lock); } =20 + /* Clear any stale errors */ + mpam_msc_clear_esr(msc); + spin_lock(&partid_max_lock); mpam_partid_max =3D min(mpam_partid_max, msc->partid_max); mpam_pmg_max =3D min(mpam_pmg_max, msc->pmg_max); @@ -860,6 +895,13 @@ static void mpam_reset_msc(struct mpam_msc *msc, bool = online) } } =20 +static void _enable_percpu_irq(void *_irq) +{ + int *irq =3D _irq; + + enable_percpu_irq(*irq, IRQ_TYPE_NONE); +} + static int mpam_cpu_online(unsigned int cpu) { struct mpam_msc *msc; @@ -870,6 +912,9 @@ static int mpam_cpu_online(unsigned int cpu) if (!cpumask_test_cpu(cpu, &msc->accessibility)) continue; =20 + if (msc->reenable_error_ppi) + _enable_percpu_irq(&msc->reenable_error_ppi); + if (atomic_fetch_inc(&msc->online_refs) =3D=3D 0) mpam_reset_msc(msc, true); } @@ -920,6 +965,9 @@ static int mpam_cpu_offline(unsigned int cpu) if (!cpumask_test_cpu(cpu, &msc->accessibility)) continue; =20 + if (msc->reenable_error_ppi) + disable_percpu_irq(msc->reenable_error_ppi); + if (atomic_dec_and_test(&msc->online_refs)) mpam_reset_msc(msc, false); } @@ -946,6 +994,42 @@ static void mpam_register_cpuhp_callbacks(int (*online= )(unsigned int online), mutex_unlock(&mpam_cpuhp_state_lock); } =20 +static int __setup_ppi(struct mpam_msc *msc) +{ + int cpu; + + msc->error_dev_id =3D alloc_percpu(struct mpam_msc *); + if (!msc->error_dev_id) + return -ENOMEM; + + for_each_cpu(cpu, &msc->accessibility) + *per_cpu_ptr(msc->error_dev_id, cpu) =3D msc; + + return 0; +} + +static int mpam_msc_setup_error_irq(struct mpam_msc *msc) +{ + int irq; + + irq =3D platform_get_irq_byname_optional(msc->pdev, "error"); + if (irq <=3D 0) + return 0; + + /* Allocate and initialise the percpu device pointer for PPI */ + if (irq_is_percpu(irq)) + return __setup_ppi(msc); + + /* sanity check: shared interrupts can be routed anywhere? */ + if (!cpumask_equal(&msc->accessibility, cpu_possible_mask)) { + pr_err_once("msc:%u is a private resource with a shared error interrupt", + msc->id); + return -EINVAL; + } + + return 0; +} + /* * An MSC can control traffic from a set of CPUs, but may only be accessib= le * from a (hopefully wider) set of CPUs. The common reason for this is pow= er @@ -1023,6 +1107,7 @@ static struct mpam_msc *do_mpam_msc_drv_probe(struct = platform_device *pdev) =20 mutex_init(&msc->probe_lock); mutex_init(&msc->part_sel_lock); + mutex_init(&msc->error_irq_lock); mpam_mon_sel_lock_init(msc); msc->id =3D pdev->id; msc->pdev =3D pdev; @@ -1037,6 +1122,10 @@ static struct mpam_msc *do_mpam_msc_drv_probe(struct= platform_device *pdev) return ERR_PTR(-EINVAL); } =20 + err =3D mpam_msc_setup_error_irq(msc); + if (err) + return ERR_PTR(err); + if (device_property_read_u32(&pdev->dev, "pcc-channel", &tmp)) msc->iface =3D MPAM_IFACE_MMIO; else @@ -1304,11 +1393,176 @@ static void mpam_enable_merge_features(struct list= _head *all_classes_list) } } =20 +static char *mpam_errcode_names[16] =3D { + [MPAM_ERRCODE_NONE] =3D "No error", + [MPAM_ERRCODE_PARTID_SEL_RANGE] =3D "PARTID_SEL_Range", + [MPAM_ERRCODE_REQ_PARTID_RANGE] =3D "Req_PARTID_Range", + [MPAM_ERRCODE_MSMONCFG_ID_RANGE] =3D "MSMONCFG_ID_RANGE", + [MPAM_ERRCODE_REQ_PMG_RANGE] =3D "Req_PMG_Range", + [MPAM_ERRCODE_MONITOR_RANGE] =3D "Monitor_Range", + [MPAM_ERRCODE_INTPARTID_RANGE] =3D "intPARTID_Range", + [MPAM_ERRCODE_UNEXPECTED_INTERNAL] =3D "Unexpected_INTERNAL", + [MPAM_ERRCODE_UNDEFINED_RIS_PART_SEL] =3D "Undefined_RIS_PART_SEL", + [MPAM_ERRCODE_RIS_NO_CONTROL] =3D "RIS_No_Control", + [MPAM_ERRCODE_UNDEFINED_RIS_MON_SEL] =3D "Undefined_RIS_MON_SEL", + [MPAM_ERRCODE_RIS_NO_MONITOR] =3D "RIS_No_Monitor", + [12 ... 15] =3D "Reserved" +}; + +static int mpam_enable_msc_ecr(void *_msc) +{ + struct mpam_msc *msc =3D _msc; + + __mpam_write_reg(msc, MPAMF_ECR, MPAMF_ECR_INTEN); + + return 0; +} + +/* This can run in mpam_disable(), and the interrupt handler on the same C= PU */ +static int mpam_disable_msc_ecr(void *_msc) +{ + struct mpam_msc *msc =3D _msc; + + __mpam_write_reg(msc, MPAMF_ECR, 0); + + return 0; +} + +static irqreturn_t __mpam_irq_handler(int irq, struct mpam_msc *msc) +{ + u64 reg; + u16 partid; + u8 errcode, pmg, ris; + + if (WARN_ON_ONCE(!msc) || + WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), + &msc->accessibility))) + return IRQ_NONE; + + reg =3D mpam_msc_read_esr(msc); + + errcode =3D FIELD_GET(MPAMF_ESR_ERRCODE, reg); + if (!errcode) + return IRQ_NONE; + + /* Clear level triggered irq */ + mpam_msc_clear_esr(msc); + + partid =3D FIELD_GET(MPAMF_ESR_PARTID_MON, reg); + pmg =3D FIELD_GET(MPAMF_ESR_PMG, reg); + ris =3D FIELD_GET(MPAMF_ESR_RIS, reg); + + pr_err_ratelimited("error irq from msc:%u '%s', partid:%u, pmg: %u, ris: = %u\n", + msc->id, mpam_errcode_names[errcode], partid, pmg, + ris); + + /* Disable this interrupt. */ + mpam_disable_msc_ecr(msc); + + /* + * Schedule the teardown work. Don't use a threaded IRQ as we can't + * unregister the interrupt from the threaded part of the handler. + */ + mpam_disable_reason =3D "hardware error interrupt"; + schedule_work(&mpam_broken_work); + + return IRQ_HANDLED; +} + +static irqreturn_t mpam_ppi_handler(int irq, void *dev_id) +{ + struct mpam_msc *msc =3D *(struct mpam_msc **)dev_id; + + return __mpam_irq_handler(irq, msc); +} + +static irqreturn_t mpam_spi_handler(int irq, void *dev_id) +{ + struct mpam_msc *msc =3D dev_id; + + return __mpam_irq_handler(irq, msc); +} + +static int mpam_register_irqs(void) +{ + int err, irq; + struct mpam_msc *msc; + + lockdep_assert_cpus_held(); + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, + srcu_read_lock_held(&mpam_srcu)) { + irq =3D platform_get_irq_byname_optional(msc->pdev, "error"); + if (irq <=3D 0) + continue; + + /* The MPAM spec says the interrupt can be SPI, PPI or LPI */ + /* We anticipate sharing the interrupt with other MSCs */ + if (irq_is_percpu(irq)) { + err =3D request_percpu_irq(irq, &mpam_ppi_handler, + "mpam:msc:error", + msc->error_dev_id); + if (err) + return err; + + msc->reenable_error_ppi =3D irq; + smp_call_function_many(&msc->accessibility, + &_enable_percpu_irq, &irq, + true); + } else { + err =3D devm_request_irq(&msc->pdev->dev,irq, + &mpam_spi_handler, IRQF_SHARED, + "mpam:msc:error", msc); + if (err) + return err; + } + + mutex_lock(&msc->error_irq_lock); + msc->error_irq_req =3D true; + mpam_touch_msc(msc, mpam_enable_msc_ecr, msc); + msc->error_irq_hw_enabled =3D true; + mutex_unlock(&msc->error_irq_lock); + } + + return 0; +} + +static void mpam_unregister_irqs(void) +{ + int irq; + struct mpam_msc *msc; + + guard(cpus_read_lock)(); + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, + srcu_read_lock_held(&mpam_srcu)) { + irq =3D platform_get_irq_byname_optional(msc->pdev, "error"); + if (irq <=3D 0) + continue; + + mutex_lock(&msc->error_irq_lock); + if (msc->error_irq_hw_enabled) { + mpam_touch_msc(msc, mpam_disable_msc_ecr, msc); + msc->error_irq_hw_enabled =3D false; + } + + if (msc->error_irq_req) { + if (irq_is_percpu(irq)) { + msc->reenable_error_ppi =3D 0; + free_percpu_irq(irq, msc->error_dev_id); + } else { + devm_free_irq(&msc->pdev->dev, irq, msc); + } + msc->error_irq_req =3D false; + } + mutex_unlock(&msc->error_irq_lock); + } +} + static void mpam_enable_once(void) { - mutex_lock(&mpam_list_lock); - mpam_enable_merge_features(&mpam_classes); - mutex_unlock(&mpam_list_lock); + int err; =20 /* * Once the cpuhp callbacks have been changed, mpam_partid_max can no @@ -1318,6 +1572,27 @@ static void mpam_enable_once(void) partid_max_published =3D true; spin_unlock(&partid_max_lock); =20 + /* + * If all the MSC have been probed, enabling the IRQs happens next. + * That involves cross-calling to a CPU that can reach the MSC, and + * the locks must be taken in this order: + */ + cpus_read_lock(); + mutex_lock(&mpam_list_lock); + mpam_enable_merge_features(&mpam_classes); + + err =3D mpam_register_irqs(); + + mutex_unlock(&mpam_list_lock); + cpus_read_unlock(); + + if (err) { + pr_warn("Failed to register irqs: %d\n", err); + mpam_disable_reason =3D "Failed to enable."; + schedule_work(&mpam_broken_work); + return; + } + mpam_register_cpuhp_callbacks(mpam_cpu_online, mpam_cpu_offline, "mpam:online"); =20 @@ -1385,6 +1660,8 @@ void mpam_disable(struct work_struct *ignored) } mutex_unlock(&mpam_cpuhp_state_lock); =20 + mpam_unregister_irqs(); + idx =3D srcu_read_lock(&mpam_srcu); list_for_each_entry_srcu(class, &mpam_classes, classes_list, srcu_read_lock_held(&mpam_srcu)) diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 9f062dd5a0bb..a04b09abd814 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -47,6 +47,11 @@ struct mpam_msc { enum mpam_msc_iface iface; u32 nrdy_usec; cpumask_t accessibility; + bool has_extd_esr; + + int reenable_error_ppi; + struct mpam_msc * __percpu *error_dev_id; + atomic_t online_refs; =20 /* @@ -60,6 +65,14 @@ struct mpam_msc { unsigned long ris_idxs; u32 ris_max; =20 + /* + * error_irq_lock is taken when registering/unregistering the error + * interrupt and maniupulating the below flags. + */ + struct mutex error_irq_lock; + bool error_irq_req; + bool error_irq_hw_enabled; + /* mpam_msc_ris of this component */ struct list_head ris; =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EE431393DD6; Fri, 17 Oct 2025 18:58:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727529; cv=none; b=pq9oJm1XBncafX+vzpW4yzFoKX8zm7WalVtIi+kQSJWe4rrDxQ1ey7EFS0lXaWTT0ikATmHrBUcRLIQa3P+XH0A5FiRFgpVC8S8w05R67jMo5xdVrHAoObVBb4TMR/St1GAPRSdmH/QZWR0dDUNkGu8omm1A30oJ6WUD8rUdQGg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727529; c=relaxed/simple; bh=TRcB3Lgafm0XAFT9OUkVIuk51jzKbPrdeHwYUl0eqKg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qfymVOvSop/ZIJpbtzFHlutD9zjuWLg9rw/+9iWsDrBlgL4txNfRIfkVYReHUKJ/gFMYy8HvvdSo0cFzGQFCGy9RBDjVluHJE/gA+i/vvYqCb67+DkL1Rb1geoCEqiHk2v3q0BN+ht7fD910+OuRBdQ3SU2/9UMJ2F1U8tD+tNM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6FE3D1515; Fri, 17 Oct 2025 11:58:39 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4831E3F66E; Fri, 17 Oct 2025 11:58:42 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 19/29] arm_mpam: Use a static key to indicate when mpam is enabled Date: Fri, 17 Oct 2025 18:56:35 +0000 Message-Id: <20251017185645.26604-20-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Once all the MSC have been probed, the system wide usable number of PARTID is known and the configuration arrays can be allocated. After this point, checking all the MSC have been probed is pointless, and the cpuhp callbacks should restore the configuration, instead of just resetting the MSC. Add a static key to enable this behaviour. This will also allow MPAM to be disabled in response to an error, and the architecture code to enable/disable the context switch of the MPAM system registers. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Removed the word 'TODO'. * Fixed a typo in the commit message. --- drivers/resctrl/mpam_devices.c | 12 ++++++++++++ drivers/resctrl/mpam_internal.h | 9 +++++++++ 2 files changed, 21 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index f18a22f825a0..ab37ed1fb5de 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -29,6 +29,8 @@ =20 #include "mpam_internal.h" =20 +DEFINE_STATIC_KEY_FALSE(mpam_enabled); /* This moves to arch code */ + /* * mpam_list_lock protects the SRCU lists when writing. Once the * mpam_enabled key is enabled these lists are read-only, @@ -929,6 +931,9 @@ static int mpam_discovery_cpu_online(unsigned int cpu) struct mpam_msc *msc; bool new_device_probed =3D false; =20 + if (mpam_is_enabled()) + return 0; + guard(srcu)(&mpam_srcu); list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, srcu_read_lock_held(&mpam_srcu)) { @@ -1459,6 +1464,10 @@ static irqreturn_t __mpam_irq_handler(int irq, struc= t mpam_msc *msc) /* Disable this interrupt. */ mpam_disable_msc_ecr(msc); =20 + /* Are we racing with the thread disabling MPAM? */ + if (!mpam_is_enabled()) + return IRQ_HANDLED; + /* * Schedule the teardown work. Don't use a threaded IRQ as we can't * unregister the interrupt from the threaded part of the handler. @@ -1593,6 +1602,7 @@ static void mpam_enable_once(void) return; } =20 + static_branch_enable(&mpam_enabled); mpam_register_cpuhp_callbacks(mpam_cpu_online, mpam_cpu_offline, "mpam:online"); =20 @@ -1660,6 +1670,8 @@ void mpam_disable(struct work_struct *ignored) } mutex_unlock(&mpam_cpuhp_state_lock); =20 + static_branch_disable(&mpam_enabled); + mpam_unregister_irqs(); =20 idx =3D srcu_read_lock(&mpam_srcu); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index a04b09abd814..d492df9a1735 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -19,8 +20,16 @@ =20 #define MPAM_MSC_MAX_NUM_RIS 16 =20 + struct platform_device; =20 +DECLARE_STATIC_KEY_FALSE(mpam_enabled); + +static inline bool mpam_is_enabled(void) +{ + return static_branch_likely(&mpam_enabled); +} + /* * Structures protected by SRCU may not be freed for a surprising amount of * time (especially if perf is running). To ensure the MPAM error interrup= t can --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D0A653DABE3; Fri, 17 Oct 2025 18:58:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727536; cv=none; b=nLcwL0UQL4CV3pMTePde/pw3rn1ZNP52CVZd04XAt1aWfbZy1D85kzfcMHx0g2MsWU40rbi9zkVXV7V8qC2cQNjsKcEqCVCXA9Hmzfqvci9ppjLxGVnmhD3aUnDBB2EbeEHcrPOIn3hU9F3KZ54FtvLjmg898j/R5H0S7K+kfaA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727536; c=relaxed/simple; bh=LENoJScp5FxujcIEwYSfW3q0cau2CBRbr8+joE3TXro=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ck/4jARZhlTkzVyOmnM4MOiI/AZHTCV3sEOMV21rqkzAbMOYYEFbmB7pHQJNXflfOpLeMLQv7hnrYJ5to12zh+TV8iNSLVaIQ0a5BWQozGpAz62GMWdAAGAsyTjLZiWgD5DryTeFdWwNpDPHiJ96jKtUW9ycSL7DMDT8jSaz2sg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ECD281595; Fri, 17 Oct 2025 11:58:44 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A1AD93F66E; Fri, 17 Oct 2025 11:58:47 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Dave Martin , Ben Horgan Subject: [PATCH v3 20/29] arm_mpam: Allow configuration to be applied and restored during cpu online Date: Fri, 17 Oct 2025 18:56:36 +0000 Message-Id: <20251017185645.26604-21-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When CPUs come online the MSC's original configuration should be restored. Add struct mpam_config to hold the configuration. This has a bitmap of features that were modified. Once the maximum partid is known, allocate a configuration array for each component, and reprogram each RIS configuration from this. CC: Dave Martin Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Call mpam_init_reset_cfg() on alloated config as 0 is not longer correct. * init_garbage() on each config - the array has to be freed in one go, but otherwise this looks weird. * Use struct initialiser in mpam_init_reset_cfg(), * Moved int err definition. * Removed srcu lock taking based on squinting at the only caller. * Moved config reset to mpam_reset_component_cfg() for re-use in mpam_reset_component_locked(), previous memset() was not enough since ze= ro no longer means reset. Changes since v1: * Switched entry_rcu to srcu versions. Changes since RFC: * Added a comment about the ordering around max_partid. * Allocate configurations after interrupts are registered to reduce churn. * Added mpam_assert_partid_sizes_fixed(); * Make reset use an all-ones instead of zero config. --- drivers/resctrl/mpam_devices.c | 284 +++++++++++++++++++++++++++++--- drivers/resctrl/mpam_internal.h | 23 +++ 2 files changed, 287 insertions(+), 20 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index ab37ed1fb5de..e990ef67df5b 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -118,6 +118,17 @@ static inline void init_garbage(struct mpam_garbage *g= arbage) { init_llist_node(&garbage->llist); } + +/* + * Once mpam is enabled, new requestors cannot further reduce the available + * partid. Assert that the size is fixed, and new requestors will be turned + * away. + */ +static void mpam_assert_partid_sizes_fixed(void) +{ + WARN_ON_ONCE(!partid_max_published); +} + static u32 __mpam_read_reg(struct mpam_msc *msc, u16 reg) { WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); @@ -366,12 +377,16 @@ static void mpam_class_destroy(struct mpam_class *cla= ss) add_to_garbage(class); } =20 +static void __destroy_component_cfg(struct mpam_component *comp); + static void mpam_comp_destroy(struct mpam_component *comp) { struct mpam_class *class =3D comp->class; =20 lockdep_assert_held(&mpam_list_lock); =20 + __destroy_component_cfg(comp); + list_del_rcu(&comp->class_list); add_to_garbage(comp); =20 @@ -812,48 +827,102 @@ static void mpam_reset_msc_bitmap(struct mpam_msc *m= sc, u16 reg, u16 wd) __mpam_write_reg(msc, reg, bm); } =20 -static void mpam_reset_ris_partid(struct mpam_msc_ris *ris, u16 partid) +/* Called via IPI. Call while holding an SRCU reference */ +static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid, + struct mpam_config *cfg) { struct mpam_msc *msc =3D ris->vmsc->msc; struct mpam_props *rprops =3D &ris->props; =20 - WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu))); - mutex_lock(&msc->part_sel_lock); __mpam_part_sel(ris->ris_idx, partid, msc); =20 - if (mpam_has_feature(mpam_feat_cpor_part, rprops)) - mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, rprops->cpbm_wd); + if (mpam_has_feature(mpam_feat_cpor_part, rprops) && + mpam_has_feature(mpam_feat_cpor_part, cfg)) { + if (cfg->reset_cpbm) + mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, + rprops->cpbm_wd); + else + mpam_write_partsel_reg(msc, CPBM, cfg->cpbm); + } =20 - if (mpam_has_feature(mpam_feat_mbw_part, rprops)) - mpam_reset_msc_bitmap(msc, MPAMCFG_MBW_PBM, rprops->mbw_pbm_bits); + if (mpam_has_feature(mpam_feat_mbw_part, rprops) && + mpam_has_feature(mpam_feat_mbw_part, cfg)) { + if (cfg->reset_mbw_pbm) + mpam_reset_msc_bitmap(msc, MPAMCFG_MBW_PBM, + rprops->mbw_pbm_bits); + else + mpam_write_partsel_reg(msc, MBW_PBM, cfg->mbw_pbm); + } =20 - if (mpam_has_feature(mpam_feat_mbw_min, rprops)) + if (mpam_has_feature(mpam_feat_mbw_min, rprops) && + mpam_has_feature(mpam_feat_mbw_min, cfg)) mpam_write_partsel_reg(msc, MBW_MIN, 0); =20 - if (mpam_has_feature(mpam_feat_mbw_max, rprops)) - mpam_write_partsel_reg(msc, MBW_MAX, MPAMCFG_MBW_MAX_MAX); + if (mpam_has_feature(mpam_feat_mbw_max, rprops) && + mpam_has_feature(mpam_feat_mbw_max, cfg)) + mpam_write_partsel_reg(msc, MBW_MAX, cfg->mbw_max); =20 mutex_unlock(&msc->part_sel_lock); } =20 +struct reprogram_ris { + struct mpam_msc_ris *ris; + struct mpam_config *cfg; +}; + +/* Call with MSC lock held */ +static int mpam_reprogram_ris(void *_arg) +{ + u16 partid, partid_max; + struct reprogram_ris *arg =3D _arg; + struct mpam_msc_ris *ris =3D arg->ris; + struct mpam_config *cfg =3D arg->cfg; + + if (ris->in_reset_state) + return 0; + + spin_lock(&partid_max_lock); + partid_max =3D mpam_partid_max; + spin_unlock(&partid_max_lock); + for (partid =3D 0; partid <=3D partid_max + 1; partid++) + mpam_reprogram_ris_partid(ris, partid, cfg); + + return 0; +} + +static void mpam_init_reset_cfg(struct mpam_config *reset_cfg) +{ + *reset_cfg =3D (struct mpam_config) { + .cpbm =3D ~0, + .mbw_pbm =3D ~0, + .mbw_max =3D MPAMCFG_MBW_MAX_MAX, + + .reset_cpbm =3D true, + .reset_mbw_pbm =3D true, + }; + bitmap_fill(reset_cfg->features, MPAM_FEATURE_LAST); +} + /* * Called via smp_call_on_cpu() to prevent migration, while still being * pre-emptible. Caller must hold mpam_srcu. */ static int mpam_reset_ris(void *arg) { - u16 partid, partid_max; + struct mpam_config reset_cfg; struct mpam_msc_ris *ris =3D arg; + struct reprogram_ris reprogram_arg; =20 if (ris->in_reset_state) return 0; =20 - spin_lock(&partid_max_lock); - partid_max =3D mpam_partid_max; - spin_unlock(&partid_max_lock); - for (partid =3D 0; partid < partid_max + 1; partid++) - mpam_reset_ris_partid(ris, partid); + mpam_init_reset_cfg(&reset_cfg); + + reprogram_arg.ris =3D ris; + reprogram_arg.cfg =3D &reset_cfg; + + mpam_reprogram_ris(&reprogram_arg); =20 return 0; } @@ -897,6 +966,39 @@ static void mpam_reset_msc(struct mpam_msc *msc, bool = online) } } =20 +static void mpam_reprogram_msc(struct mpam_msc *msc) +{ + u16 partid; + bool reset; + struct mpam_config *cfg; + struct mpam_msc_ris *ris; + + /* + * No lock for mpam_partid_max as partid_max_published has been + * set by mpam_enabled(), so the values can no longer change. + */ + mpam_assert_partid_sizes_fixed(); + + list_for_each_entry_srcu(ris, &msc->ris, msc_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!mpam_is_enabled() && !ris->in_reset_state) { + mpam_touch_msc(msc, &mpam_reset_ris, ris); + ris->in_reset_state =3D true; + continue; + } + + reset =3D true; + for (partid =3D 0; partid <=3D mpam_partid_max; partid++) { + cfg =3D &ris->vmsc->comp->cfg[partid]; + if (!bitmap_empty(cfg->features, MPAM_FEATURE_LAST)) + reset =3D false; + + mpam_reprogram_ris_partid(ris, partid, cfg); + } + ris->in_reset_state =3D reset; + } +} + static void _enable_percpu_irq(void *_irq) { int *irq =3D _irq; @@ -918,7 +1020,7 @@ static int mpam_cpu_online(unsigned int cpu) _enable_percpu_irq(&msc->reenable_error_ppi); =20 if (atomic_fetch_inc(&msc->online_refs) =3D=3D 0) - mpam_reset_msc(msc, true); + mpam_reprogram_msc(msc); } =20 return 0; @@ -1569,6 +1671,64 @@ static void mpam_unregister_irqs(void) } } =20 +static void __destroy_component_cfg(struct mpam_component *comp) +{ + add_to_garbage(comp->cfg); +} + +static void mpam_reset_component_cfg(struct mpam_component *comp) +{ + int i; + + mpam_assert_partid_sizes_fixed(); + + if (!comp->cfg) + return; + + for (i =3D 0; i < mpam_partid_max + 1; i++) + mpam_init_reset_cfg(&comp->cfg[i]); +} + +static int __allocate_component_cfg(struct mpam_component *comp) +{ + mpam_assert_partid_sizes_fixed(); + + if (comp->cfg) + return 0; + + comp->cfg =3D kcalloc(mpam_partid_max + 1, sizeof(*comp->cfg), GFP_KERNEL= ); + if (!comp->cfg) + return -ENOMEM; + + /* + * The array is free()d in one go, so only cfg[0]'s struture needs + * to be initialised. + */ + init_garbage(&comp->cfg[0].garbage); + + mpam_reset_component_cfg(comp); + + return 0; +} + +static int mpam_allocate_config(void) +{ + struct mpam_class *class; + struct mpam_component *comp; + + lockdep_assert_held(&mpam_list_lock); + + list_for_each_entry(class, &mpam_classes, classes_list) { + list_for_each_entry(comp, &class->components, class_list) { + int err =3D __allocate_component_cfg(comp); + if (err) + return err; + } + } + + return 0; +} + static void mpam_enable_once(void) { int err; @@ -1588,15 +1748,25 @@ static void mpam_enable_once(void) */ cpus_read_lock(); mutex_lock(&mpam_list_lock); - mpam_enable_merge_features(&mpam_classes); + do { + mpam_enable_merge_features(&mpam_classes); =20 - err =3D mpam_register_irqs(); + err =3D mpam_register_irqs(); + if (err) { + pr_warn("Failed to register irqs: %d\n", err); + break; + } =20 + err =3D mpam_allocate_config(); + if (err) { + pr_err("Failed to allocate configuration arrays.\n"); + break; + } + } while (0); mutex_unlock(&mpam_list_lock); cpus_read_unlock(); =20 if (err) { - pr_warn("Failed to register irqs: %d\n", err); mpam_disable_reason =3D "Failed to enable."; schedule_work(&mpam_broken_work); return; @@ -1617,6 +1787,9 @@ static void mpam_reset_component_locked(struct mpam_c= omponent *comp) struct mpam_vmsc *vmsc; =20 lockdep_assert_cpus_held(); + mpam_assert_partid_sizes_fixed(); + + mpam_reset_component_cfg(comp); =20 guard(srcu)(&mpam_srcu); list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list, @@ -1717,6 +1890,77 @@ void mpam_enable(struct work_struct *work) mpam_enable_once(); } =20 +struct mpam_write_config_arg { + struct mpam_msc_ris *ris; + struct mpam_component *comp; + u16 partid; +}; + +static int __write_config(void *arg) +{ + struct mpam_write_config_arg *c =3D arg; + + mpam_reprogram_ris_partid(c->ris, c->partid, &c->comp->cfg[c->partid]); + + return 0; +} + +#define maybe_update_config(cfg, feature, newcfg, member, changes) do { \ + if (mpam_has_feature(feature, newcfg) && \ + (newcfg)->member !=3D (cfg)->member) { \ + (cfg)->member =3D (newcfg)->member; \ + mpam_set_feature(feature, cfg); \ + \ + (changes) =3D true; \ + } \ +} while (0) + +static bool mpam_update_config(struct mpam_config *cfg, + const struct mpam_config *newcfg) +{ + bool has_changes =3D false; + + maybe_update_config(cfg, mpam_feat_cpor_part, newcfg, cpbm, has_changes); + maybe_update_config(cfg, mpam_feat_mbw_part, newcfg, mbw_pbm, has_changes= ); + maybe_update_config(cfg, mpam_feat_mbw_max, newcfg, mbw_max, has_changes); + + return has_changes; +} + +int mpam_apply_config(struct mpam_component *comp, u16 partid, + struct mpam_config *cfg) +{ + struct mpam_write_config_arg arg; + struct mpam_msc_ris *ris; + struct mpam_vmsc *vmsc; + struct mpam_msc *msc; + + lockdep_assert_cpus_held(); + + /* Don't pass in the current config! */ + WARN_ON_ONCE(&comp->cfg[partid] =3D=3D cfg); + + if (!mpam_update_config(&comp->cfg[partid], cfg)) + return 0; + + arg.comp =3D comp; + arg.partid =3D partid; + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list, + srcu_read_lock_held(&mpam_srcu)) { + msc =3D vmsc->msc; + + list_for_each_entry_srcu(ris, &vmsc->ris, vmsc_list, + srcu_read_lock_held(&mpam_srcu)) { + arg.ris =3D ris; + mpam_touch_msc(msc, __write_config, &arg); + } + } + + return 0; +} + static int __init mpam_msc_driver_init(void) { if (!system_supports_mpam()) diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index d492df9a1735..2f2a7369107b 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -182,6 +182,20 @@ struct mpam_class { struct mpam_garbage garbage; }; =20 +struct mpam_config { + /* Which configuration values are valid. */ + DECLARE_BITMAP(features, MPAM_FEATURE_LAST); + + u32 cpbm; + u32 mbw_pbm; + u16 mbw_max; + + bool reset_cpbm; + bool reset_mbw_pbm; + + struct mpam_garbage garbage; +}; + struct mpam_component { u32 comp_id; =20 @@ -190,6 +204,12 @@ struct mpam_component { =20 cpumask_t affinity; =20 + /* + * Array of configuration values, indexed by partid. + * Read from cpuhp callbacks, hold the cpuhp lock when writing. + */ + struct mpam_config *cfg; + /* member of mpam_class:components */ struct list_head class_list; =20 @@ -249,6 +269,9 @@ extern u8 mpam_pmg_max; void mpam_enable(struct work_struct *work); void mpam_disable(struct work_struct *work); =20 +int mpam_apply_config(struct mpam_component *comp, u16 partid, + struct mpam_config *cfg); + int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, cpumask_t *affinity); =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 32588337BB3; Fri, 17 Oct 2025 18:58:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727543; cv=none; b=DzKGR/JKBat2I6K3PZ4nAQVrviKuxRKXE6iZ0XUEmRRxwwlvUNsuX7EYKwxsHhgllFiIDxuQZiw+K5LFAqN6gPRM4YwO3rhTOYTjN+s853S+Br8G8gOGB563d0679KM1eusVTSjX9yNqxRL6ZZ/yrVuQwNuvUzABbVMxgZB3o8c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727543; c=relaxed/simple; bh=gG3r5a0gia/BSkGiHIXSAzfyXYv5lcR8VH12WspFZLg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cm/XwpZjT9Qi+iXZM8qKtkhg9IGRjJFK5e2mXFi2kgaeYOFyCCoD8Gy26mA5v+OXFXyGwUs6YSXB8i+yH5M8gtXJAV07klFzKh1pHKlD+lyQ2WXY8hViAs3RF4kamQFiCXCjpd2Z3sx38YztHKo9LlImfRtckhb8eGMIbjTTvRg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A26601595; Fri, 17 Oct 2025 11:58:50 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2B0813F66E; Fri, 17 Oct 2025 11:58:53 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Rohit Mathew , Zeng Heng , Dave Martin Subject: [PATCH v3 21/29] arm_mpam: Probe and reset the rest of the features Date: Fri, 17 Oct 2025 18:56:37 +0000 Message-Id: <20251017185645.26604-22-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" MPAM supports more features than are going to be exposed to resctrl. For partid other than 0, the reset values of these controls isn't known. Discover the rest of the features so they can be reset to avoid any side effects when resctrl is in use. PARTID narrowing allows MSC/RIS to support less configuration space than is usable. If this feature is found on a class of device we are likely to use, then reduce the partid_max to make it usable. This allows us to map a PARTID to itself. CC: Rohit Mathew CC: Zeng Heng CC: Dave Martin Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Moved some enum definitions in here. * Whitespace. Changes since v1: * Added reset for cassoc. * Added detection of CSU XCL. --- drivers/resctrl/mpam_devices.c | 188 ++++++++++++++++++++++++++++++++ drivers/resctrl/mpam_internal.h | 22 +++- 2 files changed, 208 insertions(+), 2 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index e990ef67df5b..19cc87aba51a 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -229,6 +229,15 @@ static void __mpam_part_sel(u8 ris_idx, u16 partid, st= ruct mpam_msc *msc) __mpam_part_sel_raw(partsel, msc); } =20 +static void __mpam_intpart_sel(u8 ris_idx, u16 intpartid, struct mpam_msc = *msc) +{ + u32 partsel =3D FIELD_PREP(MPAMCFG_PART_SEL_RIS, ris_idx) | + FIELD_PREP(MPAMCFG_PART_SEL_PARTID_SEL, intpartid) | + MPAMCFG_PART_SEL_INTERNAL; + + __mpam_part_sel_raw(partsel, msc); +} + int mpam_register_requestor(u16 partid_max, u8 pmg_max) { guard(spinlock)(&partid_max_lock); @@ -650,10 +659,34 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ri= s) struct mpam_msc *msc =3D ris->vmsc->msc; struct device *dev =3D &msc->pdev->dev; struct mpam_props *props =3D &ris->props; + struct mpam_class *class =3D ris->vmsc->comp->class; =20 lockdep_assert_held(&msc->probe_lock); lockdep_assert_held(&msc->part_sel_lock); =20 + /* Cache Capacity Partitioning */ + if (FIELD_GET(MPAMF_IDR_HAS_CCAP_PART, ris->idr)) { + u32 ccap_features =3D mpam_read_partsel_reg(msc, CCAP_IDR); + + props->cmax_wd =3D FIELD_GET(MPAMF_CCAP_IDR_CMAX_WD, ccap_features); + if (props->cmax_wd && + FIELD_GET(MPAMF_CCAP_IDR_HAS_CMAX_SOFTLIM, ccap_features)) + mpam_set_feature(mpam_feat_cmax_softlim, props); + + if (props->cmax_wd && + !FIELD_GET(MPAMF_CCAP_IDR_NO_CMAX, ccap_features)) + mpam_set_feature(mpam_feat_cmax_cmax, props); + + if (props->cmax_wd && + FIELD_GET(MPAMF_CCAP_IDR_HAS_CMIN, ccap_features)) + mpam_set_feature(mpam_feat_cmax_cmin, props); + + props->cassoc_wd =3D FIELD_GET(MPAMF_CCAP_IDR_CASSOC_WD, ccap_features); + if (props->cassoc_wd && + FIELD_GET(MPAMF_CCAP_IDR_HAS_CASSOC, ccap_features)) + mpam_set_feature(mpam_feat_cmax_cassoc, props); + } + /* Cache Portion partitioning */ if (FIELD_GET(MPAMF_IDR_HAS_CPOR_PART, ris->idr)) { u32 cpor_features =3D mpam_read_partsel_reg(msc, CPOR_IDR); @@ -676,6 +709,31 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) props->bwa_wd =3D FIELD_GET(MPAMF_MBW_IDR_BWA_WD, mbw_features); if (props->bwa_wd && FIELD_GET(MPAMF_MBW_IDR_HAS_MAX, mbw_features)) mpam_set_feature(mpam_feat_mbw_max, props); + + if (props->bwa_wd && FIELD_GET(MPAMF_MBW_IDR_HAS_MIN, mbw_features)) + mpam_set_feature(mpam_feat_mbw_min, props); + + if (props->bwa_wd && FIELD_GET(MPAMF_MBW_IDR_HAS_PROP, mbw_features)) + mpam_set_feature(mpam_feat_mbw_prop, props); + } + + /* Priority partitioning */ + if (FIELD_GET(MPAMF_IDR_HAS_PRI_PART, ris->idr)) { + u32 pri_features =3D mpam_read_partsel_reg(msc, PRI_IDR); + + props->intpri_wd =3D FIELD_GET(MPAMF_PRI_IDR_INTPRI_WD, pri_features); + if (props->intpri_wd && FIELD_GET(MPAMF_PRI_IDR_HAS_INTPRI, pri_features= )) { + mpam_set_feature(mpam_feat_intpri_part, props); + if (FIELD_GET(MPAMF_PRI_IDR_INTPRI_0_IS_LOW, pri_features)) + mpam_set_feature(mpam_feat_intpri_part_0_low, props); + } + + props->dspri_wd =3D FIELD_GET(MPAMF_PRI_IDR_DSPRI_WD, pri_features); + if (props->dspri_wd && FIELD_GET(MPAMF_PRI_IDR_HAS_DSPRI, pri_features))= { + mpam_set_feature(mpam_feat_dspri_part, props); + if (FIELD_GET(MPAMF_PRI_IDR_DSPRI_0_IS_LOW, pri_features)) + mpam_set_feature(mpam_feat_dspri_part_0_low, props); + } } =20 /* Performance Monitoring */ @@ -700,6 +758,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) =20 mpam_set_feature(mpam_feat_msmon_csu, props); =20 + if (FIELD_GET(MPAMF_CSUMON_IDR_HAS_XCL, csumonidr)) + mpam_set_feature(mpam_feat_msmon_csu_xcl, props); + /* Is NRDY hardware managed? */ hw_managed =3D mpam_ris_hw_probe_hw_nrdy(ris, CSU); if (hw_managed) @@ -721,6 +782,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) if (props->num_mbwu_mon) mpam_set_feature(mpam_feat_msmon_mbwu, props); =20 + if (FIELD_GET(MPAMF_MBWUMON_IDR_HAS_RWBW, mbwumon_idr)) + mpam_set_feature(mpam_feat_msmon_mbwu_rwbw, props); + /* Is NRDY hardware managed? */ hw_managed =3D mpam_ris_hw_probe_hw_nrdy(ris, MBWU); if (hw_managed) @@ -732,6 +796,21 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) */ } } + + /* + * RIS with PARTID narrowing don't have enough storage for one + * configuration per PARTID. If these are in a class we could use, + * reduce the supported partid_max to match the number of intpartid. + * If the class is unknown, just ignore it. + */ + if (FIELD_GET(MPAMF_IDR_HAS_PARTID_NRW, ris->idr) && + class->type !=3D MPAM_CLASS_UNKNOWN) { + u32 nrwidr =3D mpam_read_partsel_reg(msc, PARTID_NRW_IDR); + u16 partid_max =3D FIELD_GET(MPAMF_PARTID_NRW_IDR_INTPARTID_MAX, nrwidr); + + mpam_set_feature(mpam_feat_partid_nrw, props); + msc->partid_max =3D min(msc->partid_max, partid_max); + } } =20 static int mpam_msc_hw_probe(struct mpam_msc *msc) @@ -831,12 +910,28 @@ static void mpam_reset_msc_bitmap(struct mpam_msc *ms= c, u16 reg, u16 wd) static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid, struct mpam_config *cfg) { + u32 pri_val =3D 0; + u16 cmax =3D MPAMCFG_CMAX_CMAX; struct mpam_msc *msc =3D ris->vmsc->msc; struct mpam_props *rprops =3D &ris->props; + u16 dspri =3D GENMASK(rprops->dspri_wd, 0); + u16 intpri =3D GENMASK(rprops->intpri_wd, 0); =20 mutex_lock(&msc->part_sel_lock); __mpam_part_sel(ris->ris_idx, partid, msc); =20 + if (mpam_has_feature(mpam_feat_partid_nrw, rprops)) { + /* Update the intpartid mapping */ + mpam_write_partsel_reg(msc, INTPARTID, + MPAMCFG_INTPARTID_INTERNAL | partid); + + /* + * Then switch to the 'internal' partid to update the + * configuration. + */ + __mpam_intpart_sel(ris->ris_idx, partid, msc); + } + if (mpam_has_feature(mpam_feat_cpor_part, rprops) && mpam_has_feature(mpam_feat_cpor_part, cfg)) { if (cfg->reset_cpbm) @@ -863,6 +958,35 @@ static void mpam_reprogram_ris_partid(struct mpam_msc_= ris *ris, u16 partid, mpam_has_feature(mpam_feat_mbw_max, cfg)) mpam_write_partsel_reg(msc, MBW_MAX, cfg->mbw_max); =20 + if (mpam_has_feature(mpam_feat_mbw_prop, rprops) && + mpam_has_feature(mpam_feat_mbw_prop, cfg)) + mpam_write_partsel_reg(msc, MBW_PROP, 0); + + if (mpam_has_feature(mpam_feat_cmax_cmax, rprops)) + mpam_write_partsel_reg(msc, CMAX, cmax); + + if (mpam_has_feature(mpam_feat_cmax_cmin, rprops)) + mpam_write_partsel_reg(msc, CMIN, 0); + + if (mpam_has_feature(mpam_feat_cmax_cassoc, rprops)) + mpam_write_partsel_reg(msc, CASSOC, MPAMCFG_CASSOC_CASSOC); + + if (mpam_has_feature(mpam_feat_intpri_part, rprops) || + mpam_has_feature(mpam_feat_dspri_part, rprops)) { + /* aces high? */ + if (!mpam_has_feature(mpam_feat_intpri_part_0_low, rprops)) + intpri =3D 0; + if (!mpam_has_feature(mpam_feat_dspri_part_0_low, rprops)) + dspri =3D 0; + + if (mpam_has_feature(mpam_feat_intpri_part, rprops)) + pri_val |=3D FIELD_PREP(MPAMCFG_PRI_INTPRI, intpri); + if (mpam_has_feature(mpam_feat_dspri_part, rprops)) + pri_val |=3D FIELD_PREP(MPAMCFG_PRI_DSPRI, dspri); + + mpam_write_partsel_reg(msc, PRI, pri_val); + } + mutex_unlock(&msc->part_sel_lock); } =20 @@ -1297,6 +1421,18 @@ static bool mpam_has_bwa_wd_feature(struct mpam_prop= s *props) return true; if (mpam_has_feature(mpam_feat_mbw_max, props)) return true; + if (mpam_has_feature(mpam_feat_mbw_prop, props)) + return true; + return false; +} + +/* Any of these features mean the CMAX_WD field is valid. */ +static bool mpam_has_cmax_wd_feature(struct mpam_props *props) +{ + if (mpam_has_feature(mpam_feat_cmax_cmax, props)) + return true; + if (mpam_has_feature(mpam_feat_cmax_cmin, props)) + return true; return false; } =20 @@ -1355,6 +1491,23 @@ static void __props_mismatch(struct mpam_props *pare= nt, parent->bwa_wd =3D min(parent->bwa_wd, child->bwa_wd); } =20 + if (alias && !mpam_has_cmax_wd_feature(parent) && mpam_has_cmax_wd_featur= e(child)) { + parent->cmax_wd =3D child->cmax_wd; + } else if (MISMATCHED_HELPER(parent, child, mpam_has_cmax_wd_feature, + cmax_wd, alias)) { + pr_debug("%s took the min cmax_wd\n", __func__); + parent->cmax_wd =3D min(parent->cmax_wd, child->cmax_wd); + } + + if (CAN_MERGE_FEAT(parent, child, mpam_feat_cmax_cassoc, alias)) { + parent->cassoc_wd =3D child->cassoc_wd; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_cmax_cassoc, + cassoc_wd, alias)) { + pr_debug("%s cleared cassoc_wd\n", __func__); + mpam_clear_feature(mpam_feat_cmax_cassoc, parent); + parent->cassoc_wd =3D 0; + } + /* For num properties, take the minimum */ if (CAN_MERGE_FEAT(parent, child, mpam_feat_msmon_csu, alias)) { parent->num_csu_mon =3D child->num_csu_mon; @@ -1374,6 +1527,41 @@ static void __props_mismatch(struct mpam_props *pare= nt, child->num_mbwu_mon); } =20 + if (CAN_MERGE_FEAT(parent, child, mpam_feat_intpri_part, alias)) { + parent->intpri_wd =3D child->intpri_wd; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_intpri_part, + intpri_wd, alias)) { + pr_debug("%s took the min intpri_wd\n", __func__); + parent->intpri_wd =3D min(parent->intpri_wd, child->intpri_wd); + } + + if (CAN_MERGE_FEAT(parent, child, mpam_feat_dspri_part, alias)) { + parent->dspri_wd =3D child->dspri_wd; + } else if (MISMATCHED_FEAT(parent, child, mpam_feat_dspri_part, + dspri_wd, alias)) { + pr_debug("%s took the min dspri_wd\n", __func__); + parent->dspri_wd =3D min(parent->dspri_wd, child->dspri_wd); + } + + /* TODO: alias support for these two */ + /* {int,ds}pri may not have differing 0-low behaviour */ + if (mpam_has_feature(mpam_feat_intpri_part, parent) && + (!mpam_has_feature(mpam_feat_intpri_part, child) || + mpam_has_feature(mpam_feat_intpri_part_0_low, parent) !=3D + mpam_has_feature(mpam_feat_intpri_part_0_low, child))) { + pr_debug("%s cleared intpri_part\n", __func__); + mpam_clear_feature(mpam_feat_intpri_part, parent); + mpam_clear_feature(mpam_feat_intpri_part_0_low, parent); + } + if (mpam_has_feature(mpam_feat_dspri_part, parent) && + (!mpam_has_feature(mpam_feat_dspri_part, child) || + mpam_has_feature(mpam_feat_dspri_part_0_low, parent) !=3D + mpam_has_feature(mpam_feat_dspri_part_0_low, child))) { + pr_debug("%s cleared dspri_part\n", __func__); + mpam_clear_feature(mpam_feat_dspri_part, parent); + mpam_clear_feature(mpam_feat_dspri_part_0_low, parent); + } + if (alias) { /* Merge features for aliased resources */ bitmap_or(parent->features, parent->features, child->features, MPAM_FEAT= URE_LAST); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 2f2a7369107b..00edee9ebc6c 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -139,16 +139,30 @@ static inline void mpam_mon_sel_lock_init(struct mpam= _msc *msc) =20 /* Bits for mpam features bitmaps */ enum mpam_device_features { - mpam_feat_cpor_part =3D 0, + mpam_feat_cmax_softlim, + mpam_feat_cmax_cmax, + mpam_feat_cmax_cmin, + mpam_feat_cmax_cassoc, + mpam_feat_cpor_part, mpam_feat_mbw_part, mpam_feat_mbw_min, mpam_feat_mbw_max, + mpam_feat_mbw_prop, + mpam_feat_intpri_part, + mpam_feat_intpri_part_0_low, + mpam_feat_dspri_part, + mpam_feat_dspri_part_0_low, mpam_feat_msmon, mpam_feat_msmon_csu, + mpam_feat_msmon_csu_capture, + mpam_feat_msmon_csu_xcl, mpam_feat_msmon_csu_hw_nrdy, mpam_feat_msmon_mbwu, + mpam_feat_msmon_mbwu_capture, + mpam_feat_msmon_mbwu_rwbw, mpam_feat_msmon_mbwu_hw_nrdy, - MPAM_FEATURE_LAST + mpam_feat_partid_nrw, + MPAM_FEATURE_LAST, }; =20 struct mpam_props { @@ -157,6 +171,10 @@ struct mpam_props { u16 cpbm_wd; u16 mbw_pbm_bits; u16 bwa_wd; + u16 cmax_wd; + u16 cassoc_wd; + u16 intpri_wd; + u16 dspri_wd; u16 num_csu_mon; u16 num_mbwu_mon; }; --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A01DD33B950; Fri, 17 Oct 2025 18:59:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727546; cv=none; b=UxzXjUgc4ooCno5ufelzsxq5W9QiYSGSUNaZJLaqOw/XD/sbYmvQBg89SAc6bR1p8VLPj/vP+4S1vG4nSmAa/CCtN+ZTtwsnohPRraZfFOE3fZyxO/20lv2XpkHjDNm8wLmGL2Alh5ySbax7R1MdJVMU5zfs8YOr4K4g6EjnX6c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727546; c=relaxed/simple; bh=iW/zivsHRw10NCZUqinUGT4Q4Hu/R9K01q1DJOsmBl8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=G1ACQK9ajwvpOLHtBQFTmfhuiWZUHz65d1Zr6380XCpnHqQw9gvgKdjO1Z8GBWcD6S2ovWP/JhAAoivnH5QlLbF8mzsVwkBIz7CG5stHyJGbP72gpLjWo5gYh9y6QKAk7KJeOaXw+NsbtZRTwdNHXH7DR9J9dqab+uCmriXACpw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 112FA1595; Fri, 17 Oct 2025 11:58:56 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D7E103F66E; Fri, 17 Oct 2025 11:58:58 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 22/29] arm_mpam: Add helpers to allocate monitors Date: Fri, 17 Oct 2025 18:56:38 +0000 Message-Id: <20251017185645.26604-23-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" MPAM's MSC support a number of monitors, each of which supports bandwidth counters, or cache-storage-utilisation counters. To use a counter, a monitor needs to be configured. Add helpers to allocate and free CSU or MBWU monitors. Signed-off-by: James Morse Reviewed-by: Ben Horgan Reviewed-by: Jonathan Cameron Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Use ida_alloc_max() instead of ida_alloc_range(). --- drivers/resctrl/mpam_devices.c | 2 ++ drivers/resctrl/mpam_internal.h | 35 +++++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 19cc87aba51a..a29f97cd176a 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -350,6 +350,8 @@ mpam_class_alloc(u8 level_idx, enum mpam_class_types ty= pe) class->level =3D level_idx; class->type =3D type; INIT_LIST_HEAD_RCU(&class->classes_list); + ida_init(&class->ida_csu_mon); + ida_init(&class->ida_mbwu_mon); =20 list_add_rcu(&class->classes_list, &mpam_classes); =20 diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 00edee9ebc6c..96a02ea95583 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -197,6 +197,9 @@ struct mpam_class { /* member of mpam_classes */ struct list_head classes_list; =20 + struct ida ida_csu_mon; + struct ida ida_mbwu_mon; + struct mpam_garbage garbage; }; =20 @@ -275,6 +278,38 @@ struct mpam_msc_ris { struct mpam_garbage garbage; }; =20 +static inline int mpam_alloc_csu_mon(struct mpam_class *class) +{ + struct mpam_props *cprops =3D &class->props; + + if (!mpam_has_feature(mpam_feat_msmon_csu, cprops)) + return -EOPNOTSUPP; + + return ida_alloc_max(&class->ida_csu_mon, cprops->num_csu_mon - 1, + GFP_KERNEL); +} + +static inline void mpam_free_csu_mon(struct mpam_class *class, int csu_mon) +{ + ida_free(&class->ida_csu_mon, csu_mon); +} + +static inline int mpam_alloc_mbwu_mon(struct mpam_class *class) +{ + struct mpam_props *cprops =3D &class->props; + + if (!mpam_has_feature(mpam_feat_msmon_mbwu, cprops)) + return -EOPNOTSUPP; + + return ida_alloc_max(&class->ida_mbwu_mon, cprops->num_mbwu_mon - 1, + GFP_KERNEL); +} + +static inline void mpam_free_mbwu_mon(struct mpam_class *class, int mbwu_m= on) +{ + ida_free(&class->ida_mbwu_mon, mbwu_mon); +} + /* List of all classes - protected by srcu*/ extern struct srcu_struct mpam_srcu; extern struct list_head mpam_classes; --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B6CDC33B97E; Fri, 17 Oct 2025 18:59:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727551; cv=none; b=QU/udyXb2NgdyvzskJRDC/+Ty+fN+5QtQt5RuLMCQqkgXFzRK5GMl8OxyVL+qrA2qlLrfvCk9r378UDmjxrVrsCPkDp1FH6LtrsJCETawg3fy2LAV64bJqk1NXRgJu841rxBdjjNicQqd/9HacAyha4IJ8lm2Nu3i4DB0Shilfs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727551; c=relaxed/simple; bh=T+ECVoecRDGh485v6y2Dj3bDURaOMVsi0zGwkhiF2Ec=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=f6XCCRkyaEiRg2ROUy1wxA85WTRMuTSlKHyGZCig/QMgAeYyBAae0YaTe1LOLZ5yDsCwKuJqMkHj9D4ltI6wEa7gpxFY7LZ240UgU17Ib8aUPDQNb1LJb0ZRj7ErphKpCdZeRuB5DjwxycYa8OeCPEOitqYJdAm6goIvct+PS7s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4FCFF1C25; Fri, 17 Oct 2025 11:59:01 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 427283F66E; Fri, 17 Oct 2025 11:59:04 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 23/29] arm_mpam: Add mpam_msmon_read() to read monitor value Date: Fri, 17 Oct 2025 18:56:39 +0000 Message-Id: <20251017185645.26604-24-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Reading a monitor involves configuring what you want to monitor, and reading the value. Components made up of multiple MSC may need values from each MSC. MSCs may take time to configure, returning 'not ready'. The maximum 'not ready' time should have been provided by firmware. Add mpam_msmon_read() to hide all this. If (one of) the MSC returns not ready, then wait the full timeout value before trying again. CC: Shanker Donthineni Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Tested-by: Peter Newman --- Changes since v2: * Fixed ctl_val/flt_val assignment that led to always reading counter 0. * switch to using guard() version of srcu_read_lock() * Fixed use of rcu helpers when srcu is wanted. * Use return instead of break. * Moved variable declarations into the loop. * Use struct assignment instead of memset(). * Whitespace. Changes since v1: * Added XCL support. * Merged FLT/CTL constants. * a spelling mistake in a comment. * moved structrues around. --- drivers/resctrl/mpam_devices.c | 233 ++++++++++++++++++++++++++++++++ drivers/resctrl/mpam_internal.h | 19 +++ 2 files changed, 252 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index a29f97cd176a..fb5414c6b3eb 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -880,6 +880,239 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) return 0; } =20 +struct mon_read { + struct mpam_msc_ris *ris; + struct mon_cfg *ctx; + enum mpam_device_features type; + u64 *val; + int err; +}; + +static void gen_msmon_ctl_flt_vals(struct mon_read *m, u32 *ctl_val, + u32 *flt_val) +{ + struct mon_cfg *ctx =3D m->ctx; + + /* + * For CSU counters its implementation-defined what happens when not + * filtering by partid. + */ + *ctl_val =3D MSMON_CFG_x_CTL_MATCH_PARTID; + + *flt_val =3D FIELD_PREP(MSMON_CFG_x_FLT_PARTID, ctx->partid); + + if (m->ctx->match_pmg) { + *ctl_val |=3D MSMON_CFG_x_CTL_MATCH_PMG; + *flt_val |=3D FIELD_PREP(MSMON_CFG_x_FLT_PMG, ctx->pmg); + } + + switch (m->type) { + case mpam_feat_msmon_csu: + *ctl_val |=3D MSMON_CFG_CSU_CTL_TYPE_CSU; + + if (mpam_has_feature(mpam_feat_msmon_csu_xcl, &m->ris->props)) + *flt_val |=3D FIELD_PREP(MSMON_CFG_CSU_FLT_XCL, + ctx->csu_exclude_clean); + + break; + case mpam_feat_msmon_mbwu: + *ctl_val |=3D MSMON_CFG_MBWU_CTL_TYPE_MBWU; + + if (mpam_has_feature(mpam_feat_msmon_mbwu_rwbw, &m->ris->props)) + *flt_val |=3D FIELD_PREP(MSMON_CFG_MBWU_FLT_RWBW, ctx->opts); + + break; + default: + return; + } +} + +static void read_msmon_ctl_flt_vals(struct mon_read *m, u32 *ctl_val, + u32 *flt_val) +{ + struct mpam_msc *msc =3D m->ris->vmsc->msc; + + switch (m->type) { + case mpam_feat_msmon_csu: + *ctl_val =3D mpam_read_monsel_reg(msc, CFG_CSU_CTL); + *flt_val =3D mpam_read_monsel_reg(msc, CFG_CSU_FLT); + return; + case mpam_feat_msmon_mbwu: + *ctl_val =3D mpam_read_monsel_reg(msc, CFG_MBWU_CTL); + *flt_val =3D mpam_read_monsel_reg(msc, CFG_MBWU_FLT); + return; + default: + return; + } +} + +/* Remove values set by the hardware to prevent apparent mismatches. */ +static void clean_msmon_ctl_val(u32 *cur_ctl) +{ + *cur_ctl &=3D ~MSMON_CFG_x_CTL_OFLOW_STATUS; +} + +static void write_msmon_ctl_flt_vals(struct mon_read *m, u32 ctl_val, + u32 flt_val) +{ + struct mpam_msc *msc =3D m->ris->vmsc->msc; + + /* + * Write the ctl_val with the enable bit cleared, reset the counter, + * then enable counter. + */ + switch (m->type) { + case mpam_feat_msmon_csu: + mpam_write_monsel_reg(msc, CFG_CSU_FLT, flt_val); + mpam_write_monsel_reg(msc, CFG_CSU_CTL, ctl_val); + mpam_write_monsel_reg(msc, CSU, 0); + mpam_write_monsel_reg(msc, CFG_CSU_CTL, ctl_val | MSMON_CFG_x_CTL_EN); + break; + case mpam_feat_msmon_mbwu: + mpam_write_monsel_reg(msc, CFG_MBWU_FLT, flt_val); + mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val); + mpam_write_monsel_reg(msc, MBWU, 0); + mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val | MSMON_CFG_x_CTL_EN); + break; + default: + return; + } +} + +/* Call with MSC lock held */ +static void __ris_msmon_read(void *arg) +{ + u64 now; + bool nrdy =3D false; + struct mon_read *m =3D arg; + struct mon_cfg *ctx =3D m->ctx; + struct mpam_msc_ris *ris =3D m->ris; + struct mpam_props *rprops =3D &ris->props; + struct mpam_msc *msc =3D m->ris->vmsc->msc; + u32 mon_sel, ctl_val, flt_val, cur_ctl, cur_flt; + + if (!mpam_mon_sel_lock(msc)) { + m->err =3D -EIO; + return; + } + mon_sel =3D FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, ctx->mon) | + FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); + mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); + + /* + * Read the existing configuration to avoid re-writing the same values. + * This saves waiting for 'nrdy' on subsequent reads. + */ + read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); + clean_msmon_ctl_val(&cur_ctl); + gen_msmon_ctl_flt_vals(m, &ctl_val, &flt_val); + if (cur_flt !=3D flt_val || cur_ctl !=3D (ctl_val | MSMON_CFG_x_CTL_EN)) + write_msmon_ctl_flt_vals(m, ctl_val, flt_val); + + switch (m->type) { + case mpam_feat_msmon_csu: + now =3D mpam_read_monsel_reg(msc, CSU); + if (mpam_has_feature(mpam_feat_msmon_csu_hw_nrdy, rprops)) + nrdy =3D now & MSMON___NRDY; + break; + case mpam_feat_msmon_mbwu: + now =3D mpam_read_monsel_reg(msc, MBWU); + if (mpam_has_feature(mpam_feat_msmon_mbwu_hw_nrdy, rprops)) + nrdy =3D now & MSMON___NRDY; + break; + default: + m->err =3D -EINVAL; + break; + } + mpam_mon_sel_unlock(msc); + + if (nrdy) { + m->err =3D -EBUSY; + return; + } + + now =3D FIELD_GET(MSMON___VALUE, now); + *m->val +=3D now; +} + +static int _msmon_read(struct mpam_component *comp, struct mon_read *arg) +{ + int err, any_err =3D 0; + struct mpam_vmsc *vmsc; + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list, + srcu_read_lock_held(&mpam_srcu)) { + struct mpam_msc *msc =3D vmsc->msc; + struct mpam_msc_ris *ris; + + list_for_each_entry_srcu(ris, &vmsc->ris, vmsc_list, + srcu_read_lock_held(&mpam_srcu)) { + arg->ris =3D ris; + + err =3D smp_call_function_any(&msc->accessibility, + __ris_msmon_read, arg, + true); + if (!err && arg->err) + err =3D arg->err; + + /* + * Save one error to be returned to the caller, but + * keep reading counters so that get reprogrammed. On + * platforms with NRDY this lets us wait once. + */ + if (err) + any_err =3D err; + } + } + + return any_err; +} + +int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx, + enum mpam_device_features type, u64 *val) +{ + int err; + struct mon_read arg; + u64 wait_jiffies =3D 0; + struct mpam_props *cprops =3D &comp->class->props; + + might_sleep(); + + if (!mpam_is_enabled()) + return -EIO; + + if (!mpam_has_feature(type, cprops)) + return -EOPNOTSUPP; + + arg =3D (struct mon_read) { + .ctx =3D ctx, + .type =3D type, + .val =3D val, + }; + *val =3D 0; + + err =3D _msmon_read(comp, &arg); + if (err =3D=3D -EBUSY && comp->class->nrdy_usec) + wait_jiffies =3D usecs_to_jiffies(comp->class->nrdy_usec); + + while (wait_jiffies) + wait_jiffies =3D schedule_timeout_uninterruptible(wait_jiffies); + + if (err =3D=3D -EBUSY) { + arg =3D (struct mon_read) { + .ctx =3D ctx, + .type =3D type, + .val =3D val, + }; + *val =3D 0; + + err =3D _msmon_read(comp, &arg); + } + + return err; +} + static void mpam_reset_msc_bitmap(struct mpam_msc *msc, u16 reg, u16 wd) { u32 num_words, msb; diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 96a02ea95583..0c84e945c891 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -183,6 +183,22 @@ struct mpam_props { #define mpam_set_feature(_feat, x) set_bit(_feat, (x)->features) #define mpam_clear_feature(_feat, x) clear_bit(_feat, (x)->features) =20 +/* The values for MSMON_CFG_MBWU_FLT.RWBW */ +enum mon_filter_options { + COUNT_BOTH =3D 0, + COUNT_WRITE =3D 1, + COUNT_READ =3D 2, +}; + +struct mon_cfg { + u16 mon; + u8 pmg; + bool match_pmg; + bool csu_exclude_clean; + u32 partid; + enum mon_filter_options opts; +}; + struct mpam_class { /* mpam_components in this class */ struct list_head components; @@ -325,6 +341,9 @@ void mpam_disable(struct work_struct *work); int mpam_apply_config(struct mpam_component *comp, u16 partid, struct mpam_config *cfg); =20 +int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx, + enum mpam_device_features, u64 *val); + int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, cpumask_t *affinity); =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 223BB393DF6; Fri, 17 Oct 2025 18:59:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727558; cv=none; b=m52r92Gg560g9f45skl73++BP6u4i/HrqWvNPfbKoZ2TfzLFdFjha58+XE47awstWCwS5JJebu4Px9SKJsObJKwKYA9IhYLHNe69sO5AiFJPdmJAUOafDz8Qb3buDp+jdQ7eGlDN+4xkN1UqTt9z4ry31gMxcIxqgCkG+BmjFKs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727558; c=relaxed/simple; bh=Mt//lxzU+FtYQIS0DX0CI4b7c/OTyvJYIYTPZljuGz0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cigbz3Grf4mP1JYYJaXdxU5ClVcSXo4K2Optl/oj2fQpiP0/wMjBTMHSI4IGlYdRS34q7voTx1mhQW5P4Ro6arkdIaVaJc6P5D6bVSOQ48p8u+mKcgtr0GzoAEBI5gg6O+SfEPOcjJD83AA6HLGvlLt7w8Cc0IiyvfsvEgX8bLo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 97C5A1515; Fri, 17 Oct 2025 11:59:06 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 84B0B3F66E; Fri, 17 Oct 2025 11:59:09 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan Subject: [PATCH v3 24/29] arm_mpam: Track bandwidth counter state for overflow and power management Date: Fri, 17 Oct 2025 18:56:40 +0000 Message-Id: <20251017185645.26604-25-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Bandwidth counters need to run continuously to correctly reflect the bandwidth. The value read may be lower than the previous value read in the case of overflow and when the hardware is reset due to CPU hotplug. Add struct mbwu_state to track the bandwidth counter to allow overflow and power management to be handled. Tested-by: Fenghua Yu Signed-off-by: James Morse Tested-by: Peter Newman --- Changes since v2: * Removed bogus 'if (!mbwu_state)' checks. * Fixed __allocate_component_cfg() losing error return values. * Moved variable definitions into the loop. * Removed spurious lockdep assert from mpam_reset_component_cfg(). Changes since v1: * Fixed lock/unlock typo. --- drivers/resctrl/mpam_devices.c | 146 +++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 23 +++++ 2 files changed, 167 insertions(+), 2 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index fb5414c6b3eb..deb1dcc6f6b1 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -955,6 +955,7 @@ static void clean_msmon_ctl_val(u32 *cur_ctl) static void write_msmon_ctl_flt_vals(struct mon_read *m, u32 ctl_val, u32 flt_val) { + struct msmon_mbwu_state *mbwu_state; struct mpam_msc *msc =3D m->ris->vmsc->msc; =20 /* @@ -973,20 +974,31 @@ static void write_msmon_ctl_flt_vals(struct mon_read = *m, u32 ctl_val, mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val); mpam_write_monsel_reg(msc, MBWU, 0); mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val | MSMON_CFG_x_CTL_EN); + + mbwu_state =3D &m->ris->mbwu_state[m->ctx->mon]; + mbwu_state->prev_val =3D 0; + break; default: return; } } =20 +static u64 mpam_msmon_overflow_val(struct mpam_msc_ris *ris) +{ + /* TODO: scaling, and long counters */ + return GENMASK_ULL(30, 0); +} + /* Call with MSC lock held */ static void __ris_msmon_read(void *arg) { - u64 now; bool nrdy =3D false; struct mon_read *m =3D arg; + u64 now, overflow_val =3D 0; struct mon_cfg *ctx =3D m->ctx; struct mpam_msc_ris *ris =3D m->ris; + struct msmon_mbwu_state *mbwu_state; struct mpam_props *rprops =3D &ris->props; struct mpam_msc *msc =3D m->ris->vmsc->msc; u32 mon_sel, ctl_val, flt_val, cur_ctl, cur_flt; @@ -1014,11 +1026,28 @@ static void __ris_msmon_read(void *arg) now =3D mpam_read_monsel_reg(msc, CSU); if (mpam_has_feature(mpam_feat_msmon_csu_hw_nrdy, rprops)) nrdy =3D now & MSMON___NRDY; + now =3D FIELD_GET(MSMON___VALUE, now); break; case mpam_feat_msmon_mbwu: now =3D mpam_read_monsel_reg(msc, MBWU); if (mpam_has_feature(mpam_feat_msmon_mbwu_hw_nrdy, rprops)) nrdy =3D now & MSMON___NRDY; + now =3D FIELD_GET(MSMON___VALUE, now); + + if (nrdy) + break; + + mbwu_state =3D &ris->mbwu_state[ctx->mon]; + + /* Add any pre-overflow value to the mbwu_state->val */ + if (mbwu_state->prev_val > now) + overflow_val =3D mpam_msmon_overflow_val(ris) - mbwu_state->prev_val; + + mbwu_state->prev_val =3D now; + mbwu_state->correction +=3D overflow_val; + + /* Include bandwidth consumed before the last hardware reset */ + now +=3D mbwu_state->correction; break; default: m->err =3D -EINVAL; @@ -1031,7 +1060,6 @@ static void __ris_msmon_read(void *arg) return; } =20 - now =3D FIELD_GET(MSMON___VALUE, now); *m->val +=3D now; } =20 @@ -1250,6 +1278,67 @@ static int mpam_reprogram_ris(void *_arg) return 0; } =20 +/* Call with MSC lock held */ +static int mpam_restore_mbwu_state(void *_ris) +{ + int i; + struct mon_read mwbu_arg; + struct mpam_msc_ris *ris =3D _ris; + + for (i =3D 0; i < ris->props.num_mbwu_mon; i++) { + if (ris->mbwu_state[i].enabled) { + mwbu_arg.ris =3D ris; + mwbu_arg.ctx =3D &ris->mbwu_state[i].cfg; + mwbu_arg.type =3D mpam_feat_msmon_mbwu; + + __ris_msmon_read(&mwbu_arg); + } + } + + return 0; +} + +/* Call with MSC lock and held */ +static int mpam_save_mbwu_state(void *arg) +{ + int i; + u64 val; + struct mon_cfg *cfg; + u32 cur_flt, cur_ctl, mon_sel; + struct mpam_msc_ris *ris =3D arg; + struct msmon_mbwu_state *mbwu_state; + struct mpam_msc *msc =3D ris->vmsc->msc; + + for (i =3D 0; i < ris->props.num_mbwu_mon; i++) { + mbwu_state =3D &ris->mbwu_state[i]; + cfg =3D &mbwu_state->cfg; + + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + return -EIO; + + mon_sel =3D FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) | + FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); + mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); + + cur_flt =3D mpam_read_monsel_reg(msc, CFG_MBWU_FLT); + cur_ctl =3D mpam_read_monsel_reg(msc, CFG_MBWU_CTL); + mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0); + + val =3D mpam_read_monsel_reg(msc, MBWU); + mpam_write_monsel_reg(msc, MBWU, 0); + + cfg->mon =3D i; + cfg->pmg =3D FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt); + cfg->match_pmg =3D FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl); + cfg->partid =3D FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt); + mbwu_state->correction +=3D val; + mbwu_state->enabled =3D FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl); + mpam_mon_sel_unlock(msc); + } + + return 0; +} + static void mpam_init_reset_cfg(struct mpam_config *reset_cfg) { *reset_cfg =3D (struct mpam_config) { @@ -1322,6 +1411,9 @@ static void mpam_reset_msc(struct mpam_msc *msc, bool= online) * for non-zero partid may be lost while the CPUs are offline. */ ris->in_reset_state =3D online; + + if (mpam_is_enabled() && !online) + mpam_touch_msc(msc, &mpam_save_mbwu_state, ris); } } =20 @@ -1355,6 +1447,9 @@ static void mpam_reprogram_msc(struct mpam_msc *msc) mpam_reprogram_ris_partid(ris, partid, cfg); } ris->in_reset_state =3D reset; + + if (mpam_has_feature(mpam_feat_msmon_mbwu, &ris->props)) + mpam_touch_msc(msc, &mpam_restore_mbwu_state, ris); } } =20 @@ -2096,7 +2191,22 @@ static void mpam_unregister_irqs(void) =20 static void __destroy_component_cfg(struct mpam_component *comp) { + struct mpam_msc *msc; + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + + lockdep_assert_held(&mpam_list_lock); + add_to_garbage(comp->cfg); + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + msc =3D vmsc->msc; + + if (mpam_mon_sel_lock(msc)) { + list_for_each_entry(ris, &vmsc->ris, vmsc_list) + add_to_garbage(ris->mbwu_state); + mpam_mon_sel_unlock(msc); + } + } } =20 static void mpam_reset_component_cfg(struct mpam_component *comp) @@ -2114,6 +2224,8 @@ static void mpam_reset_component_cfg(struct mpam_comp= onent *comp) =20 static int __allocate_component_cfg(struct mpam_component *comp) { + struct mpam_vmsc *vmsc; + mpam_assert_partid_sizes_fixed(); =20 if (comp->cfg) @@ -2131,6 +2243,36 @@ static int __allocate_component_cfg(struct mpam_comp= onent *comp) =20 mpam_reset_component_cfg(comp); =20 + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + struct mpam_msc *msc; + struct mpam_msc_ris *ris; + struct msmon_mbwu_state *mbwu_state; + + if (!vmsc->props.num_mbwu_mon) + continue; + + msc =3D vmsc->msc; + list_for_each_entry(ris, &vmsc->ris, vmsc_list) { + if (!ris->props.num_mbwu_mon) + continue; + + mbwu_state =3D kcalloc(ris->props.num_mbwu_mon, + sizeof(*ris->mbwu_state), + GFP_KERNEL); + if (!mbwu_state) { + __destroy_component_cfg(comp); + return -ENOMEM; + } + + init_garbage(&mbwu_state[0].garbage); + + if (mpam_mon_sel_lock(msc)) { + ris->mbwu_state =3D mbwu_state; + mpam_mon_sel_unlock(msc); + } + } + } + return 0; } =20 diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 0c84e945c891..28c475d18d86 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -199,6 +199,26 @@ struct mon_cfg { enum mon_filter_options opts; }; =20 +/* + * Changes to enabled and cfg are protected by the msc->lock. + * Changes to prev_val and correction are protected by the msc's mon_sel_l= ock. + */ +struct msmon_mbwu_state { + bool enabled; + struct mon_cfg cfg; + + /* The value last read from the hardware. Used to detect overflow. */ + u64 prev_val; + + /* + * The value to add to the new reading to account for power management, + * and shifts to trigger the overflow interrupt. + */ + u64 correction; + + struct mpam_garbage garbage; +}; + struct mpam_class { /* mpam_components in this class */ struct list_head components; @@ -291,6 +311,9 @@ struct mpam_msc_ris { /* parent: */ struct mpam_vmsc *vmsc; =20 + /* msmon mbwu configuration is preserved over reset */ + struct msmon_mbwu_state *mbwu_state; + struct mpam_garbage garbage; }; =20 --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 477FA337BBF; Fri, 17 Oct 2025 18:59:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727562; cv=none; b=tpmAk6oHqxrnNo39RiaRgvZcGHgSEZLdxCL6bIRk1ci4INu/4c9b9QJYjlhNft+2ceS+jsUPxNwa5WMSEa0g8CarAuQ/QE5WEORLJl1oSA5RJY/+eehXTwFFXCq13ODi8t0EI7W9lkuHecV9qTHqfCQ8zHbWPj6Ms2Ar0UmAf2Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727562; c=relaxed/simple; bh=+/EQV6Jmf6Epvazt8JsWQV+UXM/n7rpxjhtimdcLE80=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=dUsgPqYZNHv25HZ+kY1c/6GLctIKERPZK+yIDP+53NUyFSzdXD/ItNETwX9CyYEylloc1ql5PXt4BaCFNG8+F3YU0kn/dIZSrZ6a4iGJ3aGRm1z9DZKLd8uhkRTylg0i82LZTdrYow32Oiv5hCi2rwTq4xpvzEUE8iBicp/R6rU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 026A81C2B; Fri, 17 Oct 2025 11:59:12 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CB7A43F66E; Fri, 17 Oct 2025 11:59:14 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 25/29] arm_mpam: Probe for long/lwd mbwu counters Date: Fri, 17 Oct 2025 18:56:41 +0000 Message-Id: <20251017185645.26604-26-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Rohit Mathew mpam v0.1 and versions above v1.0 support optional long counter for memory bandwidth monitoring. The MPAMF_MBWUMON_IDR register has fields indicating support for long counters. Probe these feature bits. The mpam_feat_msmon_mbwu feature is used to indicate that bandwidth monitors are supported, instead of muddling this with which size of bandwidth monitors, add an explicit 31 bit counter feature. Signed-off-by: Rohit Mathew [ morse: Added 31bit counter feature to simplify later logic ] Signed-off-by: James Morse Reviewed-by: Ben Horgan Tested-by: Fenghua Yu Reviewed-by: Jonathan Cameron Tested-by: Peter Newman --- Changes since v2: * Added 31 bit counter type feature. * Altered commit message. --- drivers/resctrl/mpam_devices.c | 13 +++++++++++-- drivers/resctrl/mpam_internal.h | 3 +++ 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index deb1dcc6f6b1..f4d07234ce10 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -777,16 +777,25 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ri= s) dev_err_once(dev, "Counters are not usable because not-ready timeout w= as not provided by firmware."); } if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_MBWU, msmon_features)) { - bool hw_managed; + bool has_long, hw_managed; u32 mbwumon_idr =3D mpam_read_partsel_reg(msc, MBWUMON_IDR); =20 props->num_mbwu_mon =3D FIELD_GET(MPAMF_MBWUMON_IDR_NUM_MON, mbwumon_id= r); - if (props->num_mbwu_mon) + if (props->num_mbwu_mon) { mpam_set_feature(mpam_feat_msmon_mbwu, props); + mpam_set_feature(mpam_feat_msmon_mbwu_31counter, props); + } =20 if (FIELD_GET(MPAMF_MBWUMON_IDR_HAS_RWBW, mbwumon_idr)) mpam_set_feature(mpam_feat_msmon_mbwu_rwbw, props); =20 + has_long =3D FIELD_GET(MPAMF_MBWUMON_IDR_HAS_LONG, mbwumon_idr); + if (props->num_mbwu_mon && has_long) { + mpam_set_feature(mpam_feat_msmon_mbwu_44counter, props); + if (FIELD_GET(MPAMF_MBWUMON_IDR_LWD, mbwumon_idr)) + mpam_set_feature(mpam_feat_msmon_mbwu_63counter, props); + } + /* Is NRDY hardware managed? */ hw_managed =3D mpam_ris_hw_probe_hw_nrdy(ris, MBWU); if (hw_managed) diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 28c475d18d86..ff38b4bbfc2b 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -158,6 +158,9 @@ enum mpam_device_features { mpam_feat_msmon_csu_xcl, mpam_feat_msmon_csu_hw_nrdy, mpam_feat_msmon_mbwu, + mpam_feat_msmon_mbwu_31counter, + mpam_feat_msmon_mbwu_44counter, + mpam_feat_msmon_mbwu_63counter, mpam_feat_msmon_mbwu_capture, mpam_feat_msmon_mbwu_rwbw, mpam_feat_msmon_mbwu_hw_nrdy, --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B10E833C53C; Fri, 17 Oct 2025 18:59:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727567; cv=none; b=iMY9QuAKsPuv9N6SYdNCbq7OXiLKKSkWENEBIcRyR5JUJJ3w6cjXGkTjd3T8V+HKb8HjaFJP6rcVEBtw0CcusrwmshqI6lBq2PD7MfCwJkcXPcLyckeOgXgB0AIGAXUEF38E0W/9jhriGD/uIIiGr1Ow9eU5FNL5khF4vEifTLw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727567; c=relaxed/simple; bh=an7L7zevAegGfdWDz/9tb667WyGhWvHkQ92vFDswzwE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=EhTToeGCMePgAJA0saK5DQ8CexzI9nOFt9fTbhDgce4JlpZTMeZzhDepfNWNZJ2Y00vADv+7x1Qc5/4xrOibLd83miMwNhuxysdMn25aZMCX6KPfRyvSBIdg19ruRU7MCKcxIAyTGig/CX7Uk30rJmcuVoZjoplwooMsSW5oNxs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5D3772720; Fri, 17 Oct 2025 11:59:17 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 372213F66E; Fri, 17 Oct 2025 11:59:20 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 26/29] arm_mpam: Use long MBWU counters if supported Date: Fri, 17 Oct 2025 18:56:42 +0000 Message-Id: <20251017185645.26604-27-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Rohit Mathew Now that the larger counter sizes are probed, make use of them. Callers of mpam_msmon_read() may not know (or care!) about the different counter sizes. Allow them to specify mpam_feat_msmon_mbwu and have the driver pick the counter to use. Only 32bit accesses to the MSC are required to be supported by the spec, but these registers are 64bits. The lower half may overflow into the higher half between two 32bit reads. To avoid this, use a helper that reads the top half multiple times to check for overflow. Signed-off-by: Rohit Mathew [morse: merged multiple patches from Rohit, added explicit counter selectio= n ] Signed-off-by: James Morse Reviewed-by: Ben Horgan Reviewed-by: Jonathan Cameron Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Removed mpam_feat_msmon_mbwu as a top-level bit for explicit 31bit count= er selection. * Allow callers of mpam_msmon_read() to specify mpam_feat_msmon_mbwu and h= ave the driver pick a supported counter size. * Rephrased commit message. Changes since v1: * Only clear OFLOW_STATUS_L on MBWU counters. Changes since RFC: * Commit message wrangling. * Refer to 31 bit counters as opposed to 32 bit (registers). --- drivers/resctrl/mpam_devices.c | 134 ++++++++++++++++++++++++++++----- 1 file changed, 116 insertions(+), 18 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index f4d07234ce10..c207a6d2832c 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -897,6 +897,48 @@ struct mon_read { int err; }; =20 +static bool mpam_ris_has_mbwu_long_counter(struct mpam_msc_ris *ris) +{ + return (mpam_has_feature(mpam_feat_msmon_mbwu_63counter, &ris->props) || + mpam_has_feature(mpam_feat_msmon_mbwu_44counter, &ris->props)); +} + +static u64 mpam_msc_read_mbwu_l(struct mpam_msc *msc) +{ + int retry =3D 3; + u32 mbwu_l_low; + u64 mbwu_l_high1, mbwu_l_high2; + + mpam_mon_sel_lock_held(msc); + + WARN_ON_ONCE((MSMON_MBWU_L + sizeof(u64)) > msc->mapped_hwpage_sz); + WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); + + mbwu_l_high2 =3D __mpam_read_reg(msc, MSMON_MBWU_L + 4); + do { + mbwu_l_high1 =3D mbwu_l_high2; + mbwu_l_low =3D __mpam_read_reg(msc, MSMON_MBWU_L); + mbwu_l_high2 =3D __mpam_read_reg(msc, MSMON_MBWU_L + 4); + + retry--; + } while (mbwu_l_high1 !=3D mbwu_l_high2 && retry > 0); + + if (mbwu_l_high1 =3D=3D mbwu_l_high2) + return (mbwu_l_high1 << 32) | mbwu_l_low; + return MSMON___NRDY_L; +} + +static void mpam_msc_zero_mbwu_l(struct mpam_msc *msc) +{ + mpam_mon_sel_lock_held(msc); + + WARN_ON_ONCE((MSMON_MBWU_L + sizeof(u64)) > msc->mapped_hwpage_sz); + WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); + + __mpam_write_reg(msc, MSMON_MBWU_L, 0); + __mpam_write_reg(msc, MSMON_MBWU_L + 4, 0); +} + static void gen_msmon_ctl_flt_vals(struct mon_read *m, u32 *ctl_val, u32 *flt_val) { @@ -924,7 +966,9 @@ static void gen_msmon_ctl_flt_vals(struct mon_read *m, = u32 *ctl_val, ctx->csu_exclude_clean); =20 break; - case mpam_feat_msmon_mbwu: + case mpam_feat_msmon_mbwu_31counter: + case mpam_feat_msmon_mbwu_44counter: + case mpam_feat_msmon_mbwu_63counter: *ctl_val |=3D MSMON_CFG_MBWU_CTL_TYPE_MBWU; =20 if (mpam_has_feature(mpam_feat_msmon_mbwu_rwbw, &m->ris->props)) @@ -946,7 +990,9 @@ static void read_msmon_ctl_flt_vals(struct mon_read *m,= u32 *ctl_val, *ctl_val =3D mpam_read_monsel_reg(msc, CFG_CSU_CTL); *flt_val =3D mpam_read_monsel_reg(msc, CFG_CSU_FLT); return; - case mpam_feat_msmon_mbwu: + case mpam_feat_msmon_mbwu_31counter: + case mpam_feat_msmon_mbwu_44counter: + case mpam_feat_msmon_mbwu_63counter: *ctl_val =3D mpam_read_monsel_reg(msc, CFG_MBWU_CTL); *flt_val =3D mpam_read_monsel_reg(msc, CFG_MBWU_FLT); return; @@ -959,6 +1005,9 @@ static void read_msmon_ctl_flt_vals(struct mon_read *m= , u32 *ctl_val, static void clean_msmon_ctl_val(u32 *cur_ctl) { *cur_ctl &=3D ~MSMON_CFG_x_CTL_OFLOW_STATUS; + + if (FIELD_GET(MSMON_CFG_x_CTL_TYPE, *cur_ctl) =3D=3D MSMON_CFG_MBWU_CTL_T= YPE_MBWU) + *cur_ctl &=3D ~MSMON_CFG_MBWU_CTL_OFLOW_STATUS_L; } =20 static void write_msmon_ctl_flt_vals(struct mon_read *m, u32 ctl_val, @@ -978,10 +1027,15 @@ static void write_msmon_ctl_flt_vals(struct mon_read= *m, u32 ctl_val, mpam_write_monsel_reg(msc, CSU, 0); mpam_write_monsel_reg(msc, CFG_CSU_CTL, ctl_val | MSMON_CFG_x_CTL_EN); break; - case mpam_feat_msmon_mbwu: + case mpam_feat_msmon_mbwu_44counter: + case mpam_feat_msmon_mbwu_63counter: + mpam_msc_zero_mbwu_l(m->ris->vmsc->msc); + fallthrough; + case mpam_feat_msmon_mbwu_31counter: mpam_write_monsel_reg(msc, CFG_MBWU_FLT, flt_val); mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val); mpam_write_monsel_reg(msc, MBWU, 0); + mpam_write_monsel_reg(msc, CFG_MBWU_CTL, ctl_val | MSMON_CFG_x_CTL_EN); =20 mbwu_state =3D &m->ris->mbwu_state[m->ctx->mon]; @@ -993,10 +1047,19 @@ static void write_msmon_ctl_flt_vals(struct mon_read= *m, u32 ctl_val, } } =20 -static u64 mpam_msmon_overflow_val(struct mpam_msc_ris *ris) +static u64 mpam_msmon_overflow_val(enum mpam_device_features type) { - /* TODO: scaling, and long counters */ - return GENMASK_ULL(30, 0); + /* TODO: implement scaling counters */ + switch (type) { + case mpam_feat_msmon_mbwu_63counter: + return GENMASK_ULL(62, 0); + case mpam_feat_msmon_mbwu_44counter: + return GENMASK_ULL(43, 0); + case mpam_feat_msmon_mbwu_31counter: + return GENMASK_ULL(30, 0); + default: + return 0; + } } =20 /* Call with MSC lock held */ @@ -1037,11 +1100,24 @@ static void __ris_msmon_read(void *arg) nrdy =3D now & MSMON___NRDY; now =3D FIELD_GET(MSMON___VALUE, now); break; - case mpam_feat_msmon_mbwu: - now =3D mpam_read_monsel_reg(msc, MBWU); - if (mpam_has_feature(mpam_feat_msmon_mbwu_hw_nrdy, rprops)) - nrdy =3D now & MSMON___NRDY; - now =3D FIELD_GET(MSMON___VALUE, now); + case mpam_feat_msmon_mbwu_31counter: + case mpam_feat_msmon_mbwu_44counter: + case mpam_feat_msmon_mbwu_63counter: + if (m->type !=3D mpam_feat_msmon_mbwu_31counter) { + now =3D mpam_msc_read_mbwu_l(msc); + if (mpam_has_feature(mpam_feat_msmon_mbwu_hw_nrdy, rprops)) + nrdy =3D now & MSMON___NRDY_L; + + if (m->type =3D=3D mpam_feat_msmon_mbwu_63counter) + now =3D FIELD_GET(MSMON___LWD_VALUE, now); + else + now =3D FIELD_GET(MSMON___L_VALUE, now); + } else { + now =3D mpam_read_monsel_reg(msc, MBWU); + if (mpam_has_feature(mpam_feat_msmon_mbwu_hw_nrdy, rprops)) + nrdy =3D now & MSMON___NRDY; + now =3D FIELD_GET(MSMON___VALUE, now); + } =20 if (nrdy) break; @@ -1050,7 +1126,7 @@ static void __ris_msmon_read(void *arg) =20 /* Add any pre-overflow value to the mbwu_state->val */ if (mbwu_state->prev_val > now) - overflow_val =3D mpam_msmon_overflow_val(ris) - mbwu_state->prev_val; + overflow_val =3D mpam_msmon_overflow_val(m->type) - mbwu_state->prev_va= l; =20 mbwu_state->prev_val =3D now; mbwu_state->correction +=3D overflow_val; @@ -1106,13 +1182,26 @@ static int _msmon_read(struct mpam_component *comp,= struct mon_read *arg) return any_err; } =20 +static enum mpam_device_features mpam_msmon_choose_counter(struct mpam_cla= ss *class) +{ + struct mpam_props *cprops =3D &class->props; + + if (mpam_has_feature(mpam_feat_msmon_mbwu_44counter, cprops)) + return mpam_feat_msmon_mbwu_44counter; + if (mpam_has_feature(mpam_feat_msmon_mbwu_63counter, cprops)) + return mpam_feat_msmon_mbwu_63counter; + + return mpam_feat_msmon_mbwu_31counter; +} + int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx, enum mpam_device_features type, u64 *val) { int err; struct mon_read arg; u64 wait_jiffies =3D 0; - struct mpam_props *cprops =3D &comp->class->props; + struct mpam_class *class =3D comp->class; + struct mpam_props *cprops =3D &class->props; =20 might_sleep(); =20 @@ -1129,9 +1218,12 @@ int mpam_msmon_read(struct mpam_component *comp, str= uct mon_cfg *ctx, }; *val =3D 0; =20 + if (type =3D=3D mpam_feat_msmon_mbwu) + type =3D mpam_msmon_choose_counter(class); + err =3D _msmon_read(comp, &arg); - if (err =3D=3D -EBUSY && comp->class->nrdy_usec) - wait_jiffies =3D usecs_to_jiffies(comp->class->nrdy_usec); + if (err =3D=3D -EBUSY && class->nrdy_usec) + wait_jiffies =3D usecs_to_jiffies(class->nrdy_usec); =20 while (wait_jiffies) wait_jiffies =3D schedule_timeout_uninterruptible(wait_jiffies); @@ -1293,12 +1385,13 @@ static int mpam_restore_mbwu_state(void *_ris) int i; struct mon_read mwbu_arg; struct mpam_msc_ris *ris =3D _ris; + struct mpam_class *class =3D ris->vmsc->comp->class; =20 for (i =3D 0; i < ris->props.num_mbwu_mon; i++) { if (ris->mbwu_state[i].enabled) { mwbu_arg.ris =3D ris; mwbu_arg.ctx =3D &ris->mbwu_state[i].cfg; - mwbu_arg.type =3D mpam_feat_msmon_mbwu; + mwbu_arg.type =3D mpam_msmon_choose_counter(class); =20 __ris_msmon_read(&mwbu_arg); } @@ -1333,8 +1426,13 @@ static int mpam_save_mbwu_state(void *arg) cur_ctl =3D mpam_read_monsel_reg(msc, CFG_MBWU_CTL); mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0); =20 - val =3D mpam_read_monsel_reg(msc, MBWU); - mpam_write_monsel_reg(msc, MBWU, 0); + if (mpam_ris_has_mbwu_long_counter(ris)) { + val =3D mpam_msc_read_mbwu_l(msc); + mpam_msc_zero_mbwu_l(msc); + } else { + val =3D mpam_read_monsel_reg(msc, MBWU); + mpam_write_monsel_reg(msc, MBWU, 0); + } =20 cfg->mon =3D i; cfg->pmg =3D FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 571AF33B976; Fri, 17 Oct 2025 18:59:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727572; cv=none; b=N0+M5TH7pbte2r3iiYt5d08KN5efPalzPSFCKMEZqE1KkxR8VFYxULeA2T0Lc/ZJ8mWdCvwDIqDN7WwdiepGHYxygfiDX795GxxwgRwrH4rpmWMXlt0T2LJgcKJap5vfUSbIAogkbwfpq8qc+VL2LeItRrCHI+Gwj+GKPnEeJBs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727572; c=relaxed/simple; bh=Dpt6i/tnWpfQ6LIvDiDIXTCIS2tD9fqDKWNVjDUPWlc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=YJt4LBPMRL9y76FBwrwvFeTl8p3rlDbEmoPbl/Dz/mePVC6b2gpqwEJ2WeOKuNWCfP+G9pqEPbFB2SqkOFPcYYnwCf+VXgTTsdNlJQKa2fIDWZDWkzp7YwZ93N7GYf3zgv8jHF1qZT3Sbqm1AFyhSmLA/Vx7z+zpVkUXcpdHdMc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B690E1C2B; Fri, 17 Oct 2025 11:59:22 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8D2AC3F66E; Fri, 17 Oct 2025 11:59:25 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Fenghua Yu Subject: [PATCH v3 27/29] arm_mpam: Add helper to reset saved mbwu state Date: Fri, 17 Oct 2025 18:56:43 +0000 Message-Id: <20251017185645.26604-28-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" resctrl expects to reset the bandwidth counters when the filesystem is mounted. To allow this, add a helper that clears the saved mbwu state. Instead of cross calling to each CPU that can access the component MSC to write to the counter, set a flag that causes it to be zero'd on the the next read. This is easily done by forcing a configuration update. Signed-off-by: James Morse Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Reviewed-by: Jonathan Cameron Tested-by: Peter Newman --- Changes since v2: * Switched to guard and fixed non _srcu list walker. * Made a comment about what is proteted by which lock a list. --- drivers/resctrl/mpam_devices.c | 46 ++++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 7 ++++- 2 files changed, 51 insertions(+), 2 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index c207a6d2832c..89d4f42168ed 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1066,9 +1066,11 @@ static u64 mpam_msmon_overflow_val(enum mpam_device_= features type) static void __ris_msmon_read(void *arg) { bool nrdy =3D false; + bool config_mismatch; struct mon_read *m =3D arg; u64 now, overflow_val =3D 0; struct mon_cfg *ctx =3D m->ctx; + bool reset_on_next_read =3D false; struct mpam_msc_ris *ris =3D m->ris; struct msmon_mbwu_state *mbwu_state; struct mpam_props *rprops =3D &ris->props; @@ -1083,6 +1085,14 @@ static void __ris_msmon_read(void *arg) FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); =20 + if (m->type =3D=3D mpam_feat_msmon_mbwu) { + mbwu_state =3D &ris->mbwu_state[ctx->mon]; + if (mbwu_state) { + reset_on_next_read =3D mbwu_state->reset_on_next_read; + mbwu_state->reset_on_next_read =3D false; + } + } + /* * Read the existing configuration to avoid re-writing the same values. * This saves waiting for 'nrdy' on subsequent reads. @@ -1090,7 +1100,10 @@ static void __ris_msmon_read(void *arg) read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); clean_msmon_ctl_val(&cur_ctl); gen_msmon_ctl_flt_vals(m, &ctl_val, &flt_val); - if (cur_flt !=3D flt_val || cur_ctl !=3D (ctl_val | MSMON_CFG_x_CTL_EN)) + config_mismatch =3D cur_flt !=3D flt_val || + cur_ctl !=3D (ctl_val | MSMON_CFG_x_CTL_EN); + + if (config_mismatch || reset_on_next_read) write_msmon_ctl_flt_vals(m, ctl_val, flt_val); =20 switch (m->type) { @@ -1242,6 +1255,37 @@ int mpam_msmon_read(struct mpam_component *comp, str= uct mon_cfg *ctx, return err; } =20 +void mpam_msmon_reset_mbwu(struct mpam_component *comp, struct mon_cfg *ct= x) +{ + struct mpam_msc *msc; + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + + if (!mpam_is_enabled()) + return; + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!mpam_has_feature(mpam_feat_msmon_mbwu, &vmsc->props)) + continue; + + msc =3D vmsc->msc; + list_for_each_entry_srcu(ris, &vmsc->ris, vmsc_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!mpam_has_feature(mpam_feat_msmon_mbwu, &ris->props)) + continue; + + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + continue; + + ris->mbwu_state[ctx->mon].correction =3D 0; + ris->mbwu_state[ctx->mon].reset_on_next_read =3D true; + mpam_mon_sel_unlock(msc); + } + } +} + static void mpam_reset_msc_bitmap(struct mpam_msc *msc, u16 reg, u16 wd) { u32 num_words, msb; diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index ff38b4bbfc2b..6632699ae814 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -204,10 +204,14 @@ struct mon_cfg { =20 /* * Changes to enabled and cfg are protected by the msc->lock. - * Changes to prev_val and correction are protected by the msc's mon_sel_l= ock. + * The msc's mon_sel_lock protects: + * - reset_on_next_read + * - prev_val + * - correction */ struct msmon_mbwu_state { bool enabled; + bool reset_on_next_read; struct mon_cfg cfg; =20 /* The value last read from the hardware. Used to detect overflow. */ @@ -369,6 +373,7 @@ int mpam_apply_config(struct mpam_component *comp, u16 = partid, =20 int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx, enum mpam_device_features, u64 *val); +void mpam_msmon_reset_mbwu(struct mpam_component *comp, struct mon_cfg *ct= x); =20 int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, cpumask_t *affinity); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BC4B133DECC; Fri, 17 Oct 2025 18:59:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727581; cv=none; b=Mp3VL8zjYP/aFjAhMFZaRjiDKJsSuIVMtNdTp2t0PiMMC+mFIIIaFIpk6HHgIQghgnSvzVX8We+CDt3xV/Z5xfi/uTOmUMd6qAU/NMPQFuGLql/6EKI1DG/SmdxyOPHHKB/ixMxtioxehFanRUUkHxcYxPwsKUVG7qo6Kbjsguo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727581; c=relaxed/simple; bh=K0mwLiCF3aoN5xrZDcwvMLC3WAISOHbtP2OzovHRFqg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=IfFU9l82eTShYoKyk3POswLvIVZGocI2H5xxbMy5j2Y+fBBhL1R6B2+3hgk8IEb7Dj19A0oXItH0Mb0kMD0nLLa4dCQDiS5XjE26QHSHNGrB9akAJ+Zl8HDJ/FYLmxGSYfLzHRWJQcnMx2zSi9WJp3idFS9u/h/e5Id6JnFA3Sg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3E6CB1595; Fri, 17 Oct 2025 11:59:28 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E98563F66E; Fri, 17 Oct 2025 11:59:30 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Jonathan Cameron , Ben Horgan Subject: [PATCH v3 28/29] arm_mpam: Add kunit test for bitmap reset Date: Fri, 17 Oct 2025 18:56:44 +0000 Message-Id: <20251017185645.26604-29-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The bitmap reset code has been a source of bugs. Add a unit test. This currently has to be built in, as the rest of the driver is builtin. Suggested-by: Jonathan Cameron Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes from v2: * Copyright year, * Comment about lockdep checks, * { } instead of { 0 } * Removed a stray newline. --- drivers/resctrl/Kconfig | 9 ++++ drivers/resctrl/mpam_devices.c | 4 ++ drivers/resctrl/test_mpam_devices.c | 69 +++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+) create mode 100644 drivers/resctrl/test_mpam_devices.c diff --git a/drivers/resctrl/Kconfig b/drivers/resctrl/Kconfig index 58c83b5c8bfd..a2e9a6130461 100644 --- a/drivers/resctrl/Kconfig +++ b/drivers/resctrl/Kconfig @@ -10,4 +10,13 @@ config ARM64_MPAM_DRIVER_DEBUG help Say yes here to enable debug messages from the MPAM driver. =20 +config MPAM_KUNIT_TEST + bool "KUnit tests for MPAM driver " if !KUNIT_ALL_TESTS + depends on KUNIT=3Dy + default KUNIT_ALL_TESTS + help + Enable this option to run tests in the MPAM driver. + + If unsure, say N. + endif diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 89d4f42168ed..0dd048279e02 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -2695,3 +2695,7 @@ static int __init mpam_msc_driver_init(void) } /* Must occur after arm64_mpam_register_cpus() from arch_initcall() */ subsys_initcall(mpam_msc_driver_init); + +#ifdef CONFIG_MPAM_KUNIT_TEST +#include "test_mpam_devices.c" +#endif diff --git a/drivers/resctrl/test_mpam_devices.c b/drivers/resctrl/test_mpa= m_devices.c new file mode 100644 index 000000000000..0cfb41b665c4 --- /dev/null +++ b/drivers/resctrl/test_mpam_devices.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2025 Arm Ltd. +/* This file is intended to be included into mpam_devices.c */ + +#include + +static void test_mpam_reset_msc_bitmap(struct kunit *test) +{ + char __iomem *buf =3D kunit_kzalloc(test, SZ_16K, GFP_KERNEL); + struct mpam_msc fake_msc =3D {}; + u32 *test_result; + + if (!buf) + return; + + fake_msc.mapped_hwpage =3D buf; + fake_msc.mapped_hwpage_sz =3D SZ_16K; + cpumask_copy(&fake_msc.accessibility, cpu_possible_mask); + + /* Satisfy lockdep checks */ + mutex_init(&fake_msc.part_sel_lock); + mutex_lock(&fake_msc.part_sel_lock); + + test_result =3D (u32 *)(buf + MPAMCFG_CPBM); + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 0); + KUNIT_EXPECT_EQ(test, test_result[0], 0); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] =3D 0; + test_result[1] =3D 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 1); + KUNIT_EXPECT_EQ(test, test_result[0], 1); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] =3D 0; + test_result[1] =3D 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 16); + KUNIT_EXPECT_EQ(test, test_result[0], 0xffff); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] =3D 0; + test_result[1] =3D 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 32); + KUNIT_EXPECT_EQ(test, test_result[0], 0xffffffff); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] =3D 0; + test_result[1] =3D 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 33); + KUNIT_EXPECT_EQ(test, test_result[0], 0xffffffff); + KUNIT_EXPECT_EQ(test, test_result[1], 1); + test_result[0] =3D 0; + test_result[1] =3D 0; + + mutex_unlock(&fake_msc.part_sel_lock); +} + +static struct kunit_case mpam_devices_test_cases[] =3D { + KUNIT_CASE(test_mpam_reset_msc_bitmap), + {} +}; + +static struct kunit_suite mpam_devices_test_suite =3D { + .name =3D "mpam_devices_test_suite", + .test_cases =3D mpam_devices_test_cases, +}; + +kunit_test_suites(&mpam_devices_test_suite); --=20 2.39.5 From nobody Sat Feb 7 21:24:00 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1C25333DEF3; Fri, 17 Oct 2025 18:59:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727585; cv=none; b=mhpy1NBbFFtrc0UyAAl1d0AxMMFrWd+Z20VGf3YK0zcUUT35l/iDIiJyuSdgqo9mX9V6JAt+sCZ4z/JdSN5sslweFokZ2DKXE1+0/L/r8nhpyR3izqOlQ3Y2Gzw2as+8ds2zpOnm86Z5ui0TO+Xmz+NwNHKkLYRjd0a6XbYZyac= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727585; c=relaxed/simple; bh=W0/oc2L5I1tI25T7cNYTIiSCCB8vbiXf5k0VZAfQB/Q=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=krwr8AOmD+viamADb8FRXmrxw7/bU9iwiB8j+oTAhVo5bPevKel6e2HjLKXCcnsA3iOD10/dOe5QrmmFeCSLEy8L5pcy/B/MdO4dUZm+yDcEs8dw6aYfyeNGK4BChiyCP9BlhQGNs7ZkCokj+icgphDnI2TMMZveRTiIm5OVDX4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 94CEF1595; Fri, 17 Oct 2025 11:59:33 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 70B3C3F66E; Fri, 17 Oct 2025 11:59:36 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan , Ben Horgan Subject: [PATCH v3 29/29] arm_mpam: Add kunit tests for props_mismatch() Date: Fri, 17 Oct 2025 18:56:45 +0000 Message-Id: <20251017185645.26604-30-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20251017185645.26604-1-james.morse@arm.com> References: <20251017185645.26604-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When features are mismatched between MSC the way features are combined to the class determines whether resctrl can support this SoC. Add some tests to illustrate the sort of thing that is expected to work, and those that must be removed. Signed-off-by: James Morse Reviewed-by: Ben Horgan Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: Peter Newman --- Changes since v2: * Comment on why packing is only needed for kunit tests, * Made the reset code a function not a macro. Changes since v1: * Waggled some words in comments. * Moved a bunch of variables to be global - shuts up a compiler warning. --- drivers/resctrl/mpam_internal.h | 14 +- drivers/resctrl/test_mpam_devices.c | 320 ++++++++++++++++++++++++++++ 2 files changed, 333 insertions(+), 1 deletion(-) diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_interna= l.h index 6632699ae814..4f25681b56ab 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -25,6 +25,12 @@ struct platform_device; =20 DECLARE_STATIC_KEY_FALSE(mpam_enabled); =20 +#ifdef CONFIG_MPAM_KUNIT_TEST +#define PACKED_FOR_KUNIT __packed +#else +#define PACKED_FOR_KUNIT +#endif + static inline bool mpam_is_enabled(void) { return static_branch_likely(&mpam_enabled); @@ -180,7 +186,13 @@ struct mpam_props { u16 dspri_wd; u16 num_csu_mon; u16 num_mbwu_mon; -}; + +/* + * Kunit tests use memset() to set up feature combinations that should be + * removed, and will false-positive if the compiler introduces padding that + * isn't cleared during sanitisation. + */ +} PACKED_FOR_KUNIT; =20 #define mpam_has_feature(_feat, x) test_bit(_feat, (x)->features) #define mpam_set_feature(_feat, x) set_bit(_feat, (x)->features) diff --git a/drivers/resctrl/test_mpam_devices.c b/drivers/resctrl/test_mpa= m_devices.c index 0cfb41b665c4..3e8d564a0c64 100644 --- a/drivers/resctrl/test_mpam_devices.c +++ b/drivers/resctrl/test_mpam_devices.c @@ -4,6 +4,324 @@ =20 #include =20 +/* + * This test catches fields that aren't being sanitised - but can't tell y= ou + * which one... + */ +static void test__props_mismatch(struct kunit *test) +{ + struct mpam_props parent =3D { 0 }; + struct mpam_props child; + + memset(&child, 0xff, sizeof(child)); + __props_mismatch(&parent, &child, false); + + memset(&child, 0, sizeof(child)); + KUNIT_EXPECT_EQ(test, memcmp(&parent, &child, sizeof(child)), 0); + + memset(&child, 0xff, sizeof(child)); + __props_mismatch(&parent, &child, true); + + KUNIT_EXPECT_EQ(test, memcmp(&parent, &child, sizeof(child)), 0); +} + +static struct list_head fake_classes_list; +static struct mpam_class fake_class =3D { 0 }; +static struct mpam_component fake_comp1 =3D { 0 }; +static struct mpam_component fake_comp2 =3D { 0 }; +static struct mpam_vmsc fake_vmsc1 =3D { 0 }; +static struct mpam_vmsc fake_vmsc2 =3D { 0 }; +static struct mpam_msc fake_msc1 =3D { 0 }; +static struct mpam_msc fake_msc2 =3D { 0 }; +static struct mpam_msc_ris fake_ris1 =3D { 0 }; +static struct mpam_msc_ris fake_ris2 =3D { 0 }; +static struct platform_device fake_pdev =3D { 0 }; + +static inline void reset_fake_hierarchy(void) +{ + INIT_LIST_HEAD(&fake_classes_list); + + memset(&fake_class, 0, sizeof(fake_class)); + fake_class.level =3D 3; + fake_class.type =3D MPAM_CLASS_CACHE; + INIT_LIST_HEAD_RCU(&fake_class.components); + INIT_LIST_HEAD(&fake_class.classes_list); + + memset(&fake_comp1, 0, sizeof(fake_comp1)); + memset(&fake_comp2, 0, sizeof(fake_comp2)); + fake_comp1.comp_id =3D 1; + fake_comp2.comp_id =3D 2; + INIT_LIST_HEAD(&fake_comp1.vmsc); + INIT_LIST_HEAD(&fake_comp1.class_list); + INIT_LIST_HEAD(&fake_comp2.vmsc); + INIT_LIST_HEAD(&fake_comp2.class_list); + + memset(&fake_vmsc1, 0, sizeof(fake_vmsc1)); + memset(&fake_vmsc2, 0, sizeof(fake_vmsc2)); + INIT_LIST_HEAD(&fake_vmsc1.ris); + INIT_LIST_HEAD(&fake_vmsc1.comp_list); + fake_vmsc1.msc =3D &fake_msc1; + INIT_LIST_HEAD(&fake_vmsc2.ris); + INIT_LIST_HEAD(&fake_vmsc2.comp_list); + fake_vmsc2.msc =3D &fake_msc2; + + memset(&fake_ris1, 0, sizeof(fake_ris1)); + memset(&fake_ris2, 0, sizeof(fake_ris2)); + fake_ris1.ris_idx =3D 1; + INIT_LIST_HEAD(&fake_ris1.msc_list); + fake_ris2.ris_idx =3D 2; + INIT_LIST_HEAD(&fake_ris2.msc_list); + + fake_msc1.pdev =3D &fake_pdev; + fake_msc2.pdev =3D &fake_pdev; + + list_add(&fake_class.classes_list, &fake_classes_list); +} + +static void test_mpam_enable_merge_features(struct kunit *test) +{ + reset_fake_hierarchy(); + + mutex_lock(&mpam_list_lock); + + /* One Class+Comp, two RIS in one vMSC with common features */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D NULL; + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D NULL; + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc1; + list_add(&fake_ris2.vmsc_list, &fake_vmsc1.ris); + + mpam_set_feature(mpam_feat_cpor_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_cpor_part, &fake_ris2.props); + fake_ris1.props.cpbm_wd =3D 4; + fake_ris2.props.cpbm_wd =3D 4; + + mpam_enable_merge_features(&fake_classes_list); + + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_cpor_part, &fake_class= .props)); + KUNIT_EXPECT_EQ(test, fake_class.props.cpbm_wd, 4); + + reset_fake_hierarchy(); + + /* One Class+Comp, two RIS in one vMSC with non-overlapping features */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D NULL; + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D NULL; + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc1; + list_add(&fake_ris2.vmsc_list, &fake_vmsc1.ris); + + mpam_set_feature(mpam_feat_cpor_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_cmax_cmin, &fake_ris2.props); + fake_ris1.props.cpbm_wd =3D 4; + fake_ris2.props.cmax_wd =3D 4; + + mpam_enable_merge_features(&fake_classes_list); + + /* Multiple RIS within one MSC controlling the same resource can be misma= tched */ + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_cpor_part, &fake_class= .props)); + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_cmax_cmin, &fake_class= .props)); + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_cmax_cmin, &fake_vmsc1= .props)); + KUNIT_EXPECT_EQ(test, fake_class.props.cpbm_wd, 4); + KUNIT_EXPECT_EQ(test, fake_vmsc1.props.cmax_wd, 4); + KUNIT_EXPECT_EQ(test, fake_class.props.cmax_wd, 4); + + reset_fake_hierarchy(); + + /* One Class+Comp, two MSC with overlapping features */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D NULL; + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D &fake_comp1; + list_add(&fake_vmsc2.comp_list, &fake_comp1.vmsc); + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc2; + list_add(&fake_ris2.vmsc_list, &fake_vmsc2.ris); + + mpam_set_feature(mpam_feat_cpor_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_cpor_part, &fake_ris2.props); + fake_ris1.props.cpbm_wd =3D 4; + fake_ris2.props.cpbm_wd =3D 4; + + mpam_enable_merge_features(&fake_classes_list); + + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_cpor_part, &fake_class= .props)); + KUNIT_EXPECT_EQ(test, fake_class.props.cpbm_wd, 4); + + reset_fake_hierarchy(); + + /* One Class+Comp, two MSC with non-overlapping features */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D NULL; + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D &fake_comp1; + list_add(&fake_vmsc2.comp_list, &fake_comp1.vmsc); + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc2; + list_add(&fake_ris2.vmsc_list, &fake_vmsc2.ris); + + mpam_set_feature(mpam_feat_cpor_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_cmax_cmin, &fake_ris2.props); + fake_ris1.props.cpbm_wd =3D 4; + fake_ris2.props.cmax_wd =3D 4; + + mpam_enable_merge_features(&fake_classes_list); + + /* + * Multiple RIS in different MSC can't control the same resource, + * mismatched features can not be supported. + */ + KUNIT_EXPECT_FALSE(test, mpam_has_feature(mpam_feat_cpor_part, &fake_clas= s.props)); + KUNIT_EXPECT_FALSE(test, mpam_has_feature(mpam_feat_cmax_cmin, &fake_clas= s.props)); + KUNIT_EXPECT_EQ(test, fake_class.props.cpbm_wd, 0); + KUNIT_EXPECT_EQ(test, fake_class.props.cmax_wd, 0); + + reset_fake_hierarchy(); + + /* One Class+Comp, two MSC with incompatible overlapping features */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D NULL; + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D &fake_comp1; + list_add(&fake_vmsc2.comp_list, &fake_comp1.vmsc); + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc2; + list_add(&fake_ris2.vmsc_list, &fake_vmsc2.ris); + + mpam_set_feature(mpam_feat_cpor_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_cpor_part, &fake_ris2.props); + mpam_set_feature(mpam_feat_mbw_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_mbw_part, &fake_ris2.props); + fake_ris1.props.cpbm_wd =3D 5; + fake_ris2.props.cpbm_wd =3D 3; + fake_ris1.props.mbw_pbm_bits =3D 5; + fake_ris2.props.mbw_pbm_bits =3D 3; + + mpam_enable_merge_features(&fake_classes_list); + + /* + * Multiple RIS in different MSC can't control the same resource, + * mismatched features can not be supported. + */ + KUNIT_EXPECT_FALSE(test, mpam_has_feature(mpam_feat_cpor_part, &fake_clas= s.props)); + KUNIT_EXPECT_FALSE(test, mpam_has_feature(mpam_feat_mbw_part, &fake_class= .props)); + KUNIT_EXPECT_EQ(test, fake_class.props.cpbm_wd, 0); + KUNIT_EXPECT_EQ(test, fake_class.props.mbw_pbm_bits, 0); + + reset_fake_hierarchy(); + + /* One Class+Comp, two MSC with overlapping features that need tweaking */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D NULL; + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D &fake_comp1; + list_add(&fake_vmsc2.comp_list, &fake_comp1.vmsc); + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc2; + list_add(&fake_ris2.vmsc_list, &fake_vmsc2.ris); + + mpam_set_feature(mpam_feat_mbw_min, &fake_ris1.props); + mpam_set_feature(mpam_feat_mbw_min, &fake_ris2.props); + mpam_set_feature(mpam_feat_cmax_cmax, &fake_ris1.props); + mpam_set_feature(mpam_feat_cmax_cmax, &fake_ris2.props); + fake_ris1.props.bwa_wd =3D 5; + fake_ris2.props.bwa_wd =3D 3; + fake_ris1.props.cmax_wd =3D 5; + fake_ris2.props.cmax_wd =3D 3; + + mpam_enable_merge_features(&fake_classes_list); + + /* + * RIS with different control properties need to be sanitised so the + * class has the common set of properties. + */ + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_mbw_min, &fake_class.p= rops)); + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_cmax_cmax, &fake_class= .props)); + KUNIT_EXPECT_EQ(test, fake_class.props.bwa_wd, 3); + KUNIT_EXPECT_EQ(test, fake_class.props.cmax_wd, 3); + + reset_fake_hierarchy(); + + /* One Class Two Comp with overlapping features */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D &fake_class; + list_add(&fake_comp2.class_list, &fake_class.components); + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D &fake_comp2; + list_add(&fake_vmsc2.comp_list, &fake_comp2.vmsc); + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc2; + list_add(&fake_ris2.vmsc_list, &fake_vmsc2.ris); + + mpam_set_feature(mpam_feat_cpor_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_cpor_part, &fake_ris2.props); + fake_ris1.props.cpbm_wd =3D 4; + fake_ris2.props.cpbm_wd =3D 4; + + mpam_enable_merge_features(&fake_classes_list); + + KUNIT_EXPECT_TRUE(test, mpam_has_feature(mpam_feat_cpor_part, &fake_class= .props)); + KUNIT_EXPECT_EQ(test, fake_class.props.cpbm_wd, 4); + + reset_fake_hierarchy(); + + /* One Class Two Comp with non-overlapping features */ + fake_comp1.class =3D &fake_class; + list_add(&fake_comp1.class_list, &fake_class.components); + fake_comp2.class =3D &fake_class; + list_add(&fake_comp2.class_list, &fake_class.components); + fake_vmsc1.comp =3D &fake_comp1; + list_add(&fake_vmsc1.comp_list, &fake_comp1.vmsc); + fake_vmsc2.comp =3D &fake_comp2; + list_add(&fake_vmsc2.comp_list, &fake_comp2.vmsc); + fake_ris1.vmsc =3D &fake_vmsc1; + list_add(&fake_ris1.vmsc_list, &fake_vmsc1.ris); + fake_ris2.vmsc =3D &fake_vmsc2; + list_add(&fake_ris2.vmsc_list, &fake_vmsc2.ris); + + mpam_set_feature(mpam_feat_cpor_part, &fake_ris1.props); + mpam_set_feature(mpam_feat_cmax_cmin, &fake_ris2.props); + fake_ris1.props.cpbm_wd =3D 4; + fake_ris2.props.cmax_wd =3D 4; + + mpam_enable_merge_features(&fake_classes_list); + + /* + * Multiple components can't control the same resource, mismatched featur= es can + * not be supported. + */ + KUNIT_EXPECT_FALSE(test, mpam_has_feature(mpam_feat_cpor_part, &fake_clas= s.props)); + KUNIT_EXPECT_FALSE(test, mpam_has_feature(mpam_feat_cmax_cmin, &fake_clas= s.props)); + KUNIT_EXPECT_EQ(test, fake_class.props.cpbm_wd, 0); + KUNIT_EXPECT_EQ(test, fake_class.props.cmax_wd, 0); + + mutex_unlock(&mpam_list_lock); +} + static void test_mpam_reset_msc_bitmap(struct kunit *test) { char __iomem *buf =3D kunit_kzalloc(test, SZ_16K, GFP_KERNEL); @@ -58,6 +376,8 @@ static void test_mpam_reset_msc_bitmap(struct kunit *tes= t) =20 static struct kunit_case mpam_devices_test_cases[] =3D { KUNIT_CASE(test_mpam_reset_msc_bitmap), + KUNIT_CASE(test_mpam_enable_merge_features), + KUNIT_CASE(test__props_mismatch), {} }; =20 --=20 2.39.5