From nobody Mon Feb 9 21:37:48 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B56F3377544; Tue, 3 Feb 2026 21:47:02 +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=1770155224; cv=none; b=cO5l/yshktsECmkcLnnB7bXCOyU2JlazuSzb9BK598mMUgrSbrg7VgDGGwXIun+4x3dlfLyzzSMt4nOoA4zaqj7X1JkmiX6Hzhv3d87n/+OfGzaY9DAyCYKueix87luiW9K7sYWRGggl8t3XNecD8Oa4l+lWpAHKScfI9YeNie0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770155224; c=relaxed/simple; bh=uBQy0X36yoBZlqK/wQbACKq0USYcFcPCufWIh26Jyj4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aXDQAmOM9V8pFujByH4VhAYUh4JeloKCtfta2xvAUWxKvEQwKG0Gnl7Mk1R3duIgfzWV/mrWgnaDovlHfo+nHbZjHZgkkR0FaHuBViAvfYXeG2keIqLHkoYR8SsGdQHScvlecBX97Ty+8ekj9wINmlzCQCve4s9LBhQjWj6j4bo= 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 A1B831063; Tue, 3 Feb 2026 13:46:55 -0800 (PST) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 771513F778; Tue, 3 Feb 2026 13:46:56 -0800 (PST) From: Ben Horgan To: ben.horgan@arm.com Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, gshan@redhat.com, james.morse@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev, zengheng4@huawei.com, linux-doc@vger.kernel.org, Shaopeng Tan Subject: [PATCH v4 31/41] arm_mpam: resctrl: Add resctrl_arch_rmid_read() and resctrl_arch_reset_rmid() Date: Tue, 3 Feb 2026 21:43:32 +0000 Message-ID: <20260203214342.584712-32-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260203214342.584712-1-ben.horgan@arm.com> References: <20260203214342.584712-1-ben.horgan@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: James Morse resctrl uses resctrl_arch_rmid_read() to read counters. CDP emulation means the counter may need reading in three different ways. The same goes for reset. The helpers behind the resctrl_arch_ functions will be re-used for the ABMC equivalent functions. Add the rounding helper for checking monitor values while we're here. Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Reviewed-by: Jonathan Cameron Signed-off-by: James Morse Signed-off-by: Ben Horgan --- Changes since rfc: cfg initialisation style code flow at end of read_mon_cdp_safe() Changes since v2: Whitespace changes Changes since v3: Update function signatures Remove abmc check --- drivers/resctrl/mpam_resctrl.c | 152 +++++++++++++++++++++++++++++++++ include/linux/arm_mpam.h | 5 ++ 2 files changed, 157 insertions(+) diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c index e2c534a68898..e8102cc74de8 100644 --- a/drivers/resctrl/mpam_resctrl.c +++ b/drivers/resctrl/mpam_resctrl.c @@ -334,6 +334,158 @@ void resctrl_arch_mon_ctx_free(struct rdt_resource *r, resctrl_arch_mon_ctx_free_no_wait(evtid, mon_idx); } =20 +static int __read_mon(struct mpam_resctrl_mon *mon, struct mpam_component = *mon_comp, + enum mpam_device_features mon_type, + int mon_idx, + enum resctrl_conf_type cdp_type, u32 closid, u32 rmid, u64 *val) +{ + struct mon_cfg cfg; + + if (!mpam_is_enabled()) + return -EINVAL; + + /* Shift closid to account for CDP */ + closid =3D resctrl_get_config_index(closid, cdp_type); + + if (mon_idx =3D=3D USE_PRE_ALLOCATED) { + int mbwu_idx =3D resctrl_arch_rmid_idx_encode(closid, rmid); + + mon_idx =3D mon->mbwu_idx_to_mon[mbwu_idx]; + if (mon_idx =3D=3D -1) + return -EINVAL; + } + + if (irqs_disabled()) { + /* Check if we can access this domain without an IPI */ + return -EIO; + } + + cfg =3D (struct mon_cfg) { + .mon =3D mon_idx, + .match_pmg =3D true, + .partid =3D closid, + .pmg =3D rmid, + }; + + return mpam_msmon_read(mon_comp, &cfg, mon_type, val); +} + +static int read_mon_cdp_safe(struct mpam_resctrl_mon *mon, struct mpam_com= ponent *mon_comp, + enum mpam_device_features mon_type, + int mon_idx, u32 closid, u32 rmid, u64 *val) +{ + if (cdp_enabled) { + u64 code_val =3D 0, data_val =3D 0; + int err; + + err =3D __read_mon(mon, mon_comp, mon_type, mon_idx, + CDP_CODE, closid, rmid, &code_val); + if (err) + return err; + + err =3D __read_mon(mon, mon_comp, mon_type, mon_idx, + CDP_DATA, closid, rmid, &data_val); + if (err) + return err; + + *val +=3D code_val + data_val; + return 0; + } + + return __read_mon(mon, mon_comp, mon_type, mon_idx, + CDP_NONE, closid, rmid, val); +} + +/* MBWU when not in ABMC mode, and CSU counters. */ +int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *= hdr, + u32 closid, u32 rmid, enum resctrl_event_id eventid, + void *arch_priv, u64 *val, void *arch_mon_ctx) +{ + struct mpam_resctrl_dom *l3_dom; + struct mpam_component *mon_comp; + u32 mon_idx =3D *(u32 *)arch_mon_ctx; + enum mpam_device_features mon_type; + struct mpam_resctrl_mon *mon =3D &mpam_resctrl_counters[eventid]; + + resctrl_arch_rmid_read_context_check(); + + if (eventid >=3D QOS_NUM_EVENTS || !mon->class) + return -EINVAL; + + l3_dom =3D container_of(hdr, struct mpam_resctrl_dom, resctrl_mon_dom.hdr= ); + mon_comp =3D l3_dom->mon_comp[eventid]; + + switch (eventid) { + case QOS_L3_OCCUP_EVENT_ID: + mon_type =3D mpam_feat_msmon_csu; + break; + case QOS_L3_MBM_LOCAL_EVENT_ID: + case QOS_L3_MBM_TOTAL_EVENT_ID: + mon_type =3D mpam_feat_msmon_mbwu; + break; + default: + return -EINVAL; + } + + return read_mon_cdp_safe(mon, mon_comp, mon_type, mon_idx, + closid, rmid, val); +} + +static void __reset_mon(struct mpam_resctrl_mon *mon, struct mpam_componen= t *mon_comp, + int mon_idx, + enum resctrl_conf_type cdp_type, u32 closid, u32 rmid) +{ + struct mon_cfg cfg =3D { }; + + if (!mpam_is_enabled()) + return; + + /* Shift closid to account for CDP */ + closid =3D resctrl_get_config_index(closid, cdp_type); + + if (mon_idx =3D=3D USE_PRE_ALLOCATED) { + int mbwu_idx =3D resctrl_arch_rmid_idx_encode(closid, rmid); + mon_idx =3D mon->mbwu_idx_to_mon[mbwu_idx]; + } + + if (mon_idx =3D=3D -1) + return; + cfg.mon =3D mon_idx; + mpam_msmon_reset_mbwu(mon_comp, &cfg); +} + +static void reset_mon_cdp_safe(struct mpam_resctrl_mon *mon, struct mpam_c= omponent *mon_comp, + int mon_idx, u32 closid, u32 rmid) +{ + if (cdp_enabled) { + __reset_mon(mon, mon_comp, mon_idx, CDP_CODE, closid, rmid); + __reset_mon(mon, mon_comp, mon_idx, CDP_DATA, closid, rmid); + } else { + __reset_mon(mon, mon_comp, mon_idx, CDP_NONE, closid, rmid); + } +} + +/* Called via IPI. Call with read_cpus_lock() held. */ +void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_l3_mon_dom= ain *d, + u32 closid, u32 rmid, enum resctrl_event_id eventid) +{ + struct mpam_resctrl_dom *l3_dom; + struct mpam_component *mon_comp; + struct mpam_resctrl_mon *mon =3D &mpam_resctrl_counters[eventid]; + + if (!mpam_is_enabled()) + return; + + /* Only MBWU counters are relevant, and for supported event types. */ + if (eventid =3D=3D QOS_L3_OCCUP_EVENT_ID || !mon->class) + return; + + l3_dom =3D container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom); + mon_comp =3D l3_dom->mon_comp[eventid]; + + reset_mon_cdp_safe(mon, mon_comp, USE_PRE_ALLOCATED, closid, rmid); +} + static bool cache_has_usable_cpor(struct mpam_class *class) { struct mpam_props *cprops =3D &class->props; diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h index e1461e32af75..86d5e326d2bd 100644 --- a/include/linux/arm_mpam.h +++ b/include/linux/arm_mpam.h @@ -67,6 +67,11 @@ struct rdt_resource; void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, enum resctrl_even= t_id evtid); void resctrl_arch_mon_ctx_free(struct rdt_resource *r, enum resctrl_event_= id evtid, void *ctx); =20 +static inline unsigned int resctrl_arch_round_mon_val(unsigned int val) +{ + return val; +} + /** * mpam_register_requestor() - Register a requestor with the MPAM driver * @partid_max: The maximum PARTID value the requestor can generate. --=20 2.43.0