From patchwork Fri May 14 09:53:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ionela Voinescu X-Patchwork-Id: 12257321 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DF3AC43460 for ; Fri, 14 May 2021 09:54:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BFA761451 for ; Fri, 14 May 2021 09:54:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232479AbhENJzj (ORCPT ); Fri, 14 May 2021 05:55:39 -0400 Received: from foss.arm.com ([217.140.110.172]:46144 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232470AbhENJzj (ORCPT ); Fri, 14 May 2021 05:55:39 -0400 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 126C8175D; Fri, 14 May 2021 02:54:28 -0700 (PDT) Received: from e108754-lin.cambridge.arm.com (unknown [10.1.195.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9B2483F719; Fri, 14 May 2021 02:54:26 -0700 (PDT) From: Ionela Voinescu To: Sudeep Holla , "Rafael J . Wysocki" , Thomas Gleixner , Ingo Molnar , Giovanni Gherdovich , Catalin Marinas , Will Deacon , Valentin Schneider Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/3] arch_topology: obtain cpu capacity using information from CPPC Date: Fri, 14 May 2021 10:53:38 +0100 Message-Id: <20210514095339.12979-3-ionela.voinescu@arm.com> X-Mailer: git-send-email 2.29.2.dirty In-Reply-To: <20210514095339.12979-1-ionela.voinescu@arm.com> References: <20210514095339.12979-1-ionela.voinescu@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Define 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 Cc: Sudeep Holla --- drivers/base/arch_topology.c | 39 +++++++++++++++++++++++++++++++++++ include/linux/arch_topology.h | 4 ++++ 2 files changed, 43 insertions(+) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index c1179edc0f3b..f710d64f125b 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -291,6 +291,45 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) return !ret; } +#ifdef CONFIG_ACPI_CPPC_LIB +#include + +void 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)) { + raw_capacity[cpu] = perf_caps.highest_perf; + pr_debug("%s: CPU%d cpu_capacity=%u (raw).\n", + __func__, cpu, raw_capacity[cpu]); + } else { + pr_err("%s: CPU%d missing highest performance.\n", + __func__, cpu); + pr_err("%s: fallback to 1024 for all CPUs\n", + __func__); + goto exit; + } + } + + topology_normalize_cpu_scale(); + schedule_work(&update_topology_flags_work); + pr_debug("%s: cpu_capacity initialization done\n", __func__); + +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); diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index f180240dc95f..fbd829c3b7f7 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 init_cpu_capacity_cppc(void); +#endif + struct device_node; bool topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu);