From nobody Mon Feb 9 17:22:47 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CE22637473F; Tue, 3 Feb 2026 21:45:45 +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=1770155147; cv=none; b=KWccdQgV6N1FVXsJoT4jS0t74rFL8MjzLTM2IC/lqIGUZv5Z2g6MvHcRsUG0SGvNh3tScjhxLvKdmt6jcj226HwbQ3lRGpcSn6/EynvtD8Fk7ENfjssYiqNpo1FRhcHesXEL5/Uga8b281ozMUNYqsQDs4xF2/mva0osCrBIAFg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770155147; c=relaxed/simple; bh=P5enqSs+IEqLAwax/N9BOfSRgq8G4ObfMICqaDEKxTo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lkcrYgls2ach3rLRs+N8dZs8AELl8jM2vvnNCvwg32rRHsvxHQruijU32t3OoSvwZTSCc66KbTL7xmvPuMQbnDTOYU6ZDrCzUm5l70ajG+AHQfNUvTnBj7LkuYbm8dGW/DZH7PIqCYpe6wAR3+ajuT2zUbGSHbE6KEQh1ULX5JI= 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 082A4497; Tue, 3 Feb 2026 13:45:39 -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 D0B833F778; Tue, 3 Feb 2026 13:45:39 -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 18/41] arm_mpam: resctrl: Implement helpers to update configuration Date: Tue, 3 Feb 2026 21:43:19 +0000 Message-ID: <20260203214342.584712-19-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 has two helpers for updating the configuration. resctrl_arch_update_one() updates a single value, and is used by the software-controller to apply feedback to the bandwidth controls, it has to be called on one of the CPUs in the resctrl:domain. resctrl_arch_update_domains() copies multiple staged configurations, it can be called from anywhere. Both helpers should update any changes to the underlying hardware. Implement resctrl_arch_update_domains() to use resctrl_arch_update_one(). Neither need to be called on a specific CPU as the mpam driver will send IPIs as needed. 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: list_for_each_entry -> list_for_each_entry_rcu return 0 Restrict scope of local variables Changes since v2: whitespace fix --- drivers/resctrl/mpam_resctrl.c | 70 ++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c index ecf00386edca..48d047510089 100644 --- a/drivers/resctrl/mpam_resctrl.c +++ b/drivers/resctrl/mpam_resctrl.c @@ -212,6 +212,76 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, st= ruct rdt_ctrl_domain *d, } } =20 +int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain= *d, + u32 closid, enum resctrl_conf_type t, u32 cfg_val) +{ + u32 partid; + struct mpam_config cfg; + struct mpam_props *cprops; + struct mpam_resctrl_res *res; + struct mpam_resctrl_dom *dom; + + lockdep_assert_cpus_held(); + lockdep_assert_irqs_enabled(); + + /* + * No need to check the CPU as mpam_apply_config() doesn't care, and + * resctrl_arch_update_domains() relies on this. + */ + res =3D container_of(r, struct mpam_resctrl_res, resctrl_res); + dom =3D container_of(d, struct mpam_resctrl_dom, resctrl_ctrl_dom); + cprops =3D &res->class->props; + + partid =3D resctrl_get_config_index(closid, t); + if (!r->alloc_capable || partid >=3D resctrl_arch_get_num_closid(r)) { + pr_debug("Not alloc capable or computed PARTID out of range\n"); + return -EINVAL; + } + + /* + * Copy the current config to avoid clearing other resources when the + * same component is exposed multiple times through resctrl. + */ + cfg =3D dom->ctrl_comp->cfg[partid]; + + switch (r->rid) { + case RDT_RESOURCE_L2: + case RDT_RESOURCE_L3: + cfg.cpbm =3D cfg_val; + mpam_set_feature(mpam_feat_cpor_part, &cfg); + break; + default: + return -EINVAL; + } + + return mpam_apply_config(dom->ctrl_comp, partid, &cfg); +} + +int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) +{ + int err; + struct rdt_ctrl_domain *d; + + lockdep_assert_cpus_held(); + lockdep_assert_irqs_enabled(); + + list_for_each_entry_rcu(d, &r->ctrl_domains, hdr.list) { + for (enum resctrl_conf_type t =3D 0; t < CDP_NUM_TYPES; t++) { + struct resctrl_staged_config *cfg =3D &d->staged_config[t]; + + if (!cfg->have_new_ctrl) + continue; + + err =3D resctrl_arch_update_one(r, d, closid, t, + cfg->new_ctrl); + if (err) + return err; + } + } + + return 0; +} + void resctrl_arch_reset_all_ctrls(struct rdt_resource *r) { struct mpam_resctrl_res *res; --=20 2.43.0