From nobody Tue Oct 7 08:51:40 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A22AD2F508C for ; Fri, 11 Jul 2025 18:37:30 +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=1752259052; cv=none; b=r/yGZhyZ9+6LPnYNRq31NrzMO0dHuVfCAKBYZ5IMufFCKo3mQTlZggNMoDwI0HU5kYlhjpKu7H2ZCE9R0oZ4XiIAqOyO+DR2t3YzvrFMSpd+PqAlWAoZWlGianTcQlrnLMKx44RRjh7kqfR4UTvzrwvS8OI2dfzYhBzWY0u7YnY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752259052; c=relaxed/simple; bh=w+DPPRXRpmpfk4eJ5CeM9pvwxKmPlD8aLWVYw5wP4Qo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=kR58gOL0a/3w1hLtZhmt3KMeavVRZZySdTzsScl3pOrabjG5NAFTsvgUNGVwB8sGFoP/Eu7zV0lnoQA7Nu2GWqaKnBstQbo/6lFVMvrhLLwrGtvSuD1Fo6o4Q2lFsit/guBOchLG7uwvi+G+4/HZQuRWYV47cfMegHtvpEfGjzw= 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 B5F0A16F8; Fri, 11 Jul 2025 11:37:19 -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 166E03F694; Fri, 11 Jul 2025 11:37:26 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Rob Herring , Ben Horgan , Rohit Mathew , Shanker Donthineni , Zeng Heng , Lecopzer Chen , Carl Worth , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , 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 , Rex Nie , Dave Martin , Koba Ko , James Morse , Rohit Mathew , Sudeep Holla Subject: [RFC PATCH 08/36] ACPI / PPTT: Add a helper to fill a cpumask from a cache_id Date: Fri, 11 Jul 2025 18:36:20 +0000 Message-Id: <20250711183648.30766-9-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20250711183648.30766-1-james.morse@arm.com> References: <20250711183648.30766-1-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 --- drivers/acpi/pptt.c | 70 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 6 ++++ 2 files changed, 76 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index f53748a5df19..81f7ac18c023 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -985,3 +985,73 @@ int find_acpi_cache_level_from_id(u32 cache_id) acpi_put_table(table); return -ENOENT; } + +/** + * acpi_pptt_get_cpumask_from_cache_id() - Get the cpus associated with the + * specified cache + * @cache_id: The id field of the unified 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) +{ + u32 acpi_cpu_id; + acpi_status status; + int level, cpu, num_levels; + 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); + + status =3D acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + acpi_pptt_warn_missing(); + return -ENOENT; + } + + if (table->revision < 3) { + acpi_put_table(table); + return -ENOENT; + } + + /* + * If we found the cache first, we'd still need to walk from each cpu. + */ + 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) + break; + acpi_count_levels(table, cpu_node, &num_levels, NULL); + + /* Start at 1 for L1 */ + for (level =3D 1; level <=3D num_levels; level++) { + cache =3D acpi_find_cache_node(table, acpi_cpu_id, + ACPI_PPTT_CACHE_TYPE_UNIFIED, + level, &cpu_node); + if (!cache) + continue; + + cache_v1 =3D ACPI_ADD_PTR(struct acpi_pptt_cache_v1, + cache, + sizeof(struct acpi_pptt_cache)); + + if (cache->flags & ACPI_PPTT_CACHE_ID_VALID && + cache_v1->cache_id =3D=3D cache_id) { + cpumask_set_cpu(cpu, cpus); + } + } + } + + acpi_put_table(table); + return 0; +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 82947f6d2a43..61ac3d1de1e8 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); int 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) { @@ -1573,6 +1574,11 @@ static inline int find_acpi_cache_level_from_id(u32 = cache_id) { return -EINVAL; } +static inline int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, + cpumask_t *cpus) +{ + return -EINVAL; +} #endif =20 void acpi_arch_init(void); --=20 2.39.5