From patchwork Thu Mar 10 14:54:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ionela Voinescu X-Patchwork-Id: 12776538 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AD15C4332F for ; Thu, 10 Mar 2022 15:05:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245537AbiCJPGy (ORCPT ); Thu, 10 Mar 2022 10:06:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245550AbiCJPF5 (ORCPT ); Thu, 10 Mar 2022 10:05:57 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 542E319ABE4; Thu, 10 Mar 2022 06:56:09 -0800 (PST) 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 3024816F2; Thu, 10 Mar 2022 06:55:46 -0800 (PST) Received: from e108754-lin.cambridge.arm.com (unknown [10.1.195.34]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 543823F7B4; Thu, 10 Mar 2022 06:55:44 -0800 (PST) From: Ionela Voinescu To: Sudeep Holla , "Rafael J . Wysocki" , Thomas Gleixner , Ingo Molnar , Giovanni Gherdovich , Catalin Marinas , Will Deacon , Valentin Schneider , Dietmar Eggemann , Sean Kelley Cc: Pierre Gondois , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Yicong Yang Subject: [PATCH v4 2/3] arch_topology: obtain cpu capacity using information from CPPC Date: Thu, 10 Mar 2022 14:54:50 +0000 Message-Id: <20220310145451.15596-3-ionela.voinescu@arm.com> X-Mailer: git-send-email 2.29.2.dirty In-Reply-To: <20220310145451.15596-1-ionela.voinescu@arm.com> References: <20220310145451.15596-1-ionela.voinescu@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Define topology_init_cpu_capacity_cppc() to use highest performance values from _CPC objects to obtain and set maximum capacity information for each CPU. acpi_cppc_processor_probe() is a good point at which to trigger the initialization of CPU (u-arch) capacity values, as at this point the highest performance values can be obtained from each CPU's _CPC objects. Architectures can therefore use this functionality through arch_init_invariance_cppc(). The performance scale used by CPPC is a unified scale for all CPUs in the system. Therefore, by obtaining the raw highest performance values from the _CPC objects, and normalizing them on the [0, 1024] capacity scale, used by the task scheduler, we obtain the CPU capacity of each CPU. While an ACPI Notify(0x85) could alert about a change in the highest performance value, which should in turn retrigger the CPU capacity computations, this notification is not currently handled by the ACPI processor driver. When supported, a call to arch_init_invariance_cppc() would perform the update. Signed-off-by: Ionela Voinescu Acked-by: Sudeep Holla Tested-by: Valentin Schneider Tested-by: Yicong Yang Cc: Sudeep Holla --- drivers/base/arch_topology.c | 45 ++++++++++++++++++++++++++++++++--- include/linux/arch_topology.h | 4 ++++ 2 files changed, 46 insertions(+), 3 deletions(-) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 976154140f0b..1d6636ebaac5 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -339,6 +339,46 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) return !ret; } +#ifdef CONFIG_ACPI_CPPC_LIB +#include + +void topology_init_cpu_capacity_cppc(void) +{ + struct cppc_perf_caps perf_caps; + int cpu; + + if (likely(acpi_disabled || !acpi_cpc_valid())) + return; + + raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity), + GFP_KERNEL); + if (!raw_capacity) + return; + + for_each_possible_cpu(cpu) { + if (!cppc_get_perf_caps(cpu, &perf_caps) && + (perf_caps.highest_perf >= perf_caps.nominal_perf) && + (perf_caps.highest_perf >= perf_caps.lowest_perf)) { + raw_capacity[cpu] = perf_caps.highest_perf; + pr_debug("cpu_capacity: CPU%d cpu_capacity=%u (raw).\n", + cpu, raw_capacity[cpu]); + continue; + } + + pr_err("cpu_capacity: CPU%d missing/invalid highest performance.\n", cpu); + pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n"); + goto exit; + } + + topology_normalize_cpu_scale(); + schedule_work(&update_topology_flags_work); + pr_debug("cpu_capacity: cpu_capacity initialization done\n"); + +exit: + free_raw_capacity(); +} +#endif + #ifdef CONFIG_CPU_FREQ static cpumask_var_t cpus_to_visit; static void parsing_done_workfn(struct work_struct *work); @@ -387,9 +427,8 @@ static int __init register_cpufreq_notifier(void) int ret; /* - * on ACPI-based systems we need to use the default cpu capacity - * until we have the necessary code to parse the cpu capacity, so - * skip registering cpufreq notifier. + * On ACPI-based systems skip registering cpufreq notifier as cpufreq + * information is not needed for cpu capacity initialization. */ if (!acpi_disabled || !raw_capacity) return -EINVAL; diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index cce6136b300a..58cbe18d825c 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -11,6 +11,10 @@ void topology_normalize_cpu_scale(void); int topology_update_cpu_topology(void); +#ifdef CONFIG_ACPI_CPPC_LIB +void topology_init_cpu_capacity_cppc(void); +#endif + struct device_node; bool topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu);