From patchwork Thu Apr 7 08:16:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 559933 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 D23BBC433F5 for ; Thu, 7 Apr 2022 08:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242738AbiDGIUc (ORCPT ); Thu, 7 Apr 2022 04:20:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238178AbiDGIU1 (ORCPT ); Thu, 7 Apr 2022 04:20:27 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3731217E341; Thu, 7 Apr 2022 01:18:28 -0700 (PDT) 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 03E31139F; Thu, 7 Apr 2022 01:18:28 -0700 (PDT) Received: from e126645.nice.arm.com (e126645.nice.arm.com [10.34.129.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1563B3F5A1; Thu, 7 Apr 2022 01:18:23 -0700 (PDT) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: Ionela.Voinescu@arm.com, Lukasz.Luba@arm.com, Morten.Rasmussen@arm.com, Dietmar.Eggemann@arm.com, maz@kernel.org, Pierre Gondois , Catalin Marinas , Will Deacon , "Rafael J. Wysocki" , Viresh Kumar , Mark Rutland , Ard Biesheuvel , Fuad Tabba , Valentin Schneider , Rob Herring , linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Subject: [PATCH v2 1/3] cpufreq: CPPC: Add cppc_cpufreq_search_cpu_data Date: Thu, 7 Apr 2022 10:16:16 +0200 Message-Id: <20220407081620.1662192-2-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220407081620.1662192-1-pierre.gondois@arm.com> References: <20220407081620.1662192-1-pierre.gondois@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Pierre Gondois cppc_cpufreq_get_cpu_data() allocates a new struct cppc_cpudata for the input CPU at each call. To search the struct associated with a cpu without allocating a new one, add cppc_cpufreq_search_cpu_data(). Also add an early prototype. This will be used in a later patch, when generating artificial performance states to register an artificial Energy Model in the cppc_cpufreq driver and enable the Energy Aware Scheduler for ACPI based systems. Signed-off-by: Pierre Gondois --- drivers/cpufreq/cppc_cpufreq.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 82d370ae6a4a..ffcd9704add2 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -41,6 +41,8 @@ */ static LIST_HEAD(cpu_data_list); +static struct cppc_cpudata *cppc_cpufreq_search_cpu_data(unsigned int cpu); + static bool boost_supported; struct cppc_workaround_oem_info { @@ -479,6 +481,19 @@ static void cppc_cpufreq_put_cpu_data(struct cpufreq_policy *policy) policy->driver_data = NULL; } +static struct cppc_cpudata * +cppc_cpufreq_search_cpu_data(unsigned int cpu) +{ + struct cppc_cpudata *iter, *tmp; + + list_for_each_entry_safe(iter, tmp, &cpu_data_list, node) { + if (cpumask_test_cpu(cpu, iter->shared_cpu_map)) + return iter; + } + + return NULL; +} + static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy) { unsigned int cpu = policy->cpu; From patchwork Thu Apr 7 08:16:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 558668 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 9DB2BC433FE for ; Thu, 7 Apr 2022 08:18:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242698AbiDGIUf (ORCPT ); Thu, 7 Apr 2022 04:20:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242803AbiDGIUe (ORCPT ); Thu, 7 Apr 2022 04:20:34 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7985F7B126; Thu, 7 Apr 2022 01:18:35 -0700 (PDT) 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 47B9B11FB; Thu, 7 Apr 2022 01:18:35 -0700 (PDT) Received: from e126645.nice.arm.com (e126645.nice.arm.com [10.34.129.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2BD3E3F5A1; Thu, 7 Apr 2022 01:18:31 -0700 (PDT) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: Ionela.Voinescu@arm.com, Lukasz.Luba@arm.com, Morten.Rasmussen@arm.com, Dietmar.Eggemann@arm.com, maz@kernel.org, Pierre Gondois , Catalin Marinas , Will Deacon , "Rafael J. Wysocki" , Viresh Kumar , Mark Rutland , Ard Biesheuvel , Fuad Tabba , Rob Herring , Valentin Schneider , Lee Jones , linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Subject: [PATCH v2 2/3] cpufreq: CPPC: Add per_cpu efficiency_class Date: Thu, 7 Apr 2022 10:16:17 +0200 Message-Id: <20220407081620.1662192-3-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220407081620.1662192-1-pierre.gondois@arm.com> References: <20220407081620.1662192-1-pierre.gondois@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Pierre Gondois In ACPI, describing power efficiency of CPUs can be done through the following arm specific field: ACPI 6.4, s5.2.12.14 'GIC CPU Interface (GICC) Structure', 'Processor Power Efficiency Class field': Describes the relative power efficiency of the associated pro- cessor. Lower efficiency class numbers are more efficient than higher ones (e.g. efficiency class 0 should be treated as more efficient than efficiency class 1). However, absolute values of this number have no meaning: 2 isn’t necessarily half as efficient as 1. The efficiency_class field is stored in the GicC structure of the ACPI MADT table and it's currently supported in Linux for arm64 only. Thus, this new functionality is introduced for arm64 only. To allow the cppc_cpufreq driver to know and preprocess the efficiency_class values of all the CPUs, add a per_cpu efficiency_class variable to store them. Also add a static efficiency_class_populated to let the driver know efficiency_class values are usable and register an artificial Energy Model (EM) based on normalized class values. At least 2 different efficiency classes must be present, otherwise there is no use in creating an Energy Model. The efficiency_class values are squeezed in [0:#efficiency_class-1] while conserving the order. For instance, efficiency classes of: [111, 212, 250] will be mapped to: [0 (was 111), 1 (was 212), 2 (was 250)]. Each policy being independently registered in the driver, populating the per_cpu efficiency_class is done only once at the driver initialization. This prevents from having each policy re-searching the efficiency_class values of other CPUs. The patch also exports acpi_cpu_get_madt_gicc() to fetch the GicC structure of the ACPI MADT table for each CPU. Signed-off-by: Pierre Gondois Acked-by: Catalin Marinas --- arch/arm64/kernel/smp.c | 1 + drivers/cpufreq/cppc_cpufreq.c | 44 ++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 27df5c1e6baa..67243011279d 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -512,6 +512,7 @@ struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu) { return &cpu_madt_gicc[cpu]; } +EXPORT_SYMBOL_GPL(acpi_cpu_get_madt_gicc); /* * acpi_map_gic_cpu_interface - parse processor MADT entry diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index ffcd9704add2..67a9f48939b6 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -422,12 +422,55 @@ static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu) return cppc_get_transition_latency(cpu) / NSEC_PER_USEC; } +static bool efficiency_class_populated; +static DEFINE_PER_CPU(unsigned int, efficiency_class); + +static int populate_efficiency_class(void) +{ + struct acpi_madt_generic_interrupt *gicc; + DECLARE_BITMAP(used_classes, 256) = {}; + int class, cpu, index; + + for_each_possible_cpu(cpu) { + gicc = acpi_cpu_get_madt_gicc(cpu); + class = gicc->efficiency_class; + bitmap_set(used_classes, class, 1); + } + + if (bitmap_weight(used_classes, 256) <= 1) { + pr_debug("Efficiency classes are all equal (=%d). " + "No EM registered", class); + return -EINVAL; + } + + /* + * Squeeze efficiency class values on [0:#efficiency_class-1]. + * Values are per spec in [0:255]. + */ + index = 0; + for_each_set_bit(class, used_classes, 256) { + for_each_possible_cpu(cpu) { + gicc = acpi_cpu_get_madt_gicc(cpu); + if (gicc->efficiency_class == class) + per_cpu(efficiency_class, cpu) = index; + } + index++; + } + + efficiency_class_populated = true; + return 0; +} + #else static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu) { return cppc_get_transition_latency(cpu) / NSEC_PER_USEC; } +static int populate_efficiency_class(void) +{ + return 0; +} #endif @@ -757,6 +800,7 @@ static int __init cppc_cpufreq_init(void) cppc_check_hisi_workaround(); cppc_freq_invariance_init(); + populate_efficiency_class(); ret = cpufreq_register_driver(&cppc_cpufreq_driver); if (ret) From patchwork Thu Apr 7 08:16:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 559932 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 E359AC433F5 for ; Thu, 7 Apr 2022 08:18:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242874AbiDGIUt (ORCPT ); Thu, 7 Apr 2022 04:20:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242852AbiDGIUm (ORCPT ); Thu, 7 Apr 2022 04:20:42 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6F37C21E511; Thu, 7 Apr 2022 01:18:42 -0700 (PDT) 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 23E0911FB; Thu, 7 Apr 2022 01:18:42 -0700 (PDT) Received: from e126645.nice.arm.com (e126645.nice.arm.com [10.34.129.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6D9E43F5A1; Thu, 7 Apr 2022 01:18:38 -0700 (PDT) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: Ionela.Voinescu@arm.com, Lukasz.Luba@arm.com, Morten.Rasmussen@arm.com, Dietmar.Eggemann@arm.com, maz@kernel.org, Pierre Gondois , Catalin Marinas , Will Deacon , "Rafael J. Wysocki" , Viresh Kumar , Ard Biesheuvel , Mark Rutland , Fuad Tabba , Sudeep Holla , Rob Herring , Lee Jones , linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Subject: [PATCH v2 3/3] cpufreq: CPPC: Register EM based on efficiency class information Date: Thu, 7 Apr 2022 10:16:18 +0200 Message-Id: <20220407081620.1662192-4-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220407081620.1662192-1-pierre.gondois@arm.com> References: <20220407081620.1662192-1-pierre.gondois@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Pierre Gondois Performance states and energy consumption values are not advertised in ACPI. In the GicC structure of the MADT table, the "Processor Power Efficiency Class field" (called efficiency class from now) allows to describe the relative energy efficiency of CPUs. To leverage the EM and EAS, the CPPC driver creates a set of artificial performance states and registers them in the Energy Model (EM), such as: - Every 20 capacity unit, a performance state is created. - The energy cost of each performance state gradually increases. No power value is generated as only the cost is used in the EM. During task placement, a task can raise the frequency of its whole pd. This can make EAS place a task on a pd with CPUs that are individually less energy efficient. As cost values are artificial, and to place tasks on CPUs with the lower efficiency class, a gap in cost values is generated for adjacent efficiency classes. E.g.: - efficiency class = 0, capacity is in [0-1024], so cost values are in [0: 51] (one performance state every 20 capacity unit) - efficiency class = 1, capacity is in [0-1024], cost values are in [1*gap+0: 1*gap+51]. The value of the cost gap is chosen to absorb a the energy of 4 CPUs at their maximum capacity. This means that between: 1- a pd of 4 CPUs, each of them being used at almost their full capacity. Their efficiency class is N. 2- a CPU using almost none of its capacity. Its efficiency class is N+1 EAS will choose the first option. Signed-off-by: Pierre Gondois --- drivers/cpufreq/cppc_cpufreq.c | 142 +++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 67a9f48939b6..181d49de669d 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -425,6 +425,129 @@ static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu) static bool efficiency_class_populated; static DEFINE_PER_CPU(unsigned int, efficiency_class); +/* Create an artificial performance state every CPPC_EM_CAP_STEP capacity unit. */ +#define CPPC_EM_CAP_STEP (20) +/* Increase the cost value by CPPC_EM_COST_STEP every performance state. */ +#define CPPC_EM_COST_STEP (1) +/* Add a cost gap correspnding to the energy of 4 CPUs. */ +#define CPPC_EM_COST_GAP (4 * SCHED_CAPACITY_SCALE * CPPC_EM_COST_STEP \ + / CPPC_EM_CAP_STEP) + +static unsigned int get_perf_level_count(struct cpufreq_policy *policy) +{ + struct cppc_perf_caps *perf_caps; + unsigned int min_cap, max_cap; + struct cppc_cpudata *cpu_data; + int cpu = policy->cpu; + + cpu_data = cppc_cpufreq_search_cpu_data(cpu); + perf_caps = &cpu_data->perf_caps; + max_cap = arch_scale_cpu_capacity(cpu); + min_cap = div_u64(max_cap * perf_caps->lowest_perf, perf_caps->highest_perf); + if ((min_cap == 0) || (max_cap < min_cap)) + return 0; + return 1 + max_cap / CPPC_EM_CAP_STEP - min_cap / CPPC_EM_CAP_STEP; +} + +/* + * The cost is defined as: + * cost = power * max_frequency / frequency + */ +static inline unsigned long compute_cost(int cpu, int step) +{ + return CPPC_EM_COST_GAP * per_cpu(efficiency_class, cpu) + + step * CPPC_EM_COST_STEP; +} + +static int cppc_get_cpu_power(struct device *cpu_dev, + unsigned long *power, unsigned long *KHz) +{ + unsigned long perf_step, perf_prev, perf, perf_check; + unsigned int min_step, max_step, step, step_check; + unsigned long prev_freq = *KHz; + unsigned int min_cap, max_cap; + + struct cppc_perf_caps *perf_caps; + struct cppc_cpudata *cpu_data; + + cpu_data = cppc_cpufreq_search_cpu_data(cpu_dev->id); + perf_caps = &cpu_data->perf_caps; + max_cap = arch_scale_cpu_capacity(cpu_dev->id); + min_cap = div_u64(max_cap * perf_caps->lowest_perf, + perf_caps->highest_perf); + + perf_step = CPPC_EM_CAP_STEP * perf_caps->highest_perf / max_cap; + min_step = min_cap / CPPC_EM_CAP_STEP; + max_step = max_cap / CPPC_EM_CAP_STEP; + + perf_prev = cppc_cpufreq_khz_to_perf(cpu_data, *KHz); + step = perf_prev / perf_step; + + if (step > max_step) + return -EINVAL; + + if (min_step == max_step) { + step = max_step; + perf = perf_caps->highest_perf; + } else if (step < min_step) { + step = min_step; + perf = perf_caps->lowest_perf; + } else { + step++; + if (step == max_step) + perf = perf_caps->highest_perf; + else + perf = step * perf_step; + } + + *KHz = cppc_cpufreq_perf_to_khz(cpu_data, perf); + perf_check = cppc_cpufreq_khz_to_perf(cpu_data, *KHz); + step_check = perf_check / perf_step; + + /* + * To avoid bad integer approximation, check that new frequency value + * increased and that the new frequency will be converted to the + * desired step value. + */ + while ((*KHz == prev_freq) || (step_check != step)) { + perf++; + *KHz = cppc_cpufreq_perf_to_khz(cpu_data, perf); + perf_check = cppc_cpufreq_khz_to_perf(cpu_data, *KHz); + step_check = perf_check / perf_step; + } + + /* + * With an artificial EM, only the cost value is used. Still the power + * is populated such as 0 < power < EM_MAX_POWER. This allows to add + * more sense to the artificial performance states. + */ + *power = compute_cost(cpu_dev->id, step); + + return 0; +} + +static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz, + unsigned long *cost) +{ + unsigned long perf_step, perf_prev; + struct cppc_perf_caps *perf_caps; + struct cppc_cpudata *cpu_data; + unsigned int max_cap; + int step; + + cpu_data = cppc_cpufreq_search_cpu_data(cpu_dev->id); + perf_caps = &cpu_data->perf_caps; + max_cap = arch_scale_cpu_capacity(cpu_dev->id); + + perf_prev = cppc_cpufreq_khz_to_perf(cpu_data, KHz); + perf_step = CPPC_EM_CAP_STEP * perf_caps->highest_perf / max_cap; + step = perf_prev / perf_step; + + *cost = compute_cost(cpu_dev->id, step); + + return 0; +} + static int populate_efficiency_class(void) { struct acpi_madt_generic_interrupt *gicc; @@ -461,6 +584,21 @@ static int populate_efficiency_class(void) return 0; } +static void cppc_cpufreq_register_em(struct cpufreq_policy *policy) +{ + struct cppc_cpudata *cpu_data; + struct em_data_callback em_cb = + EM_ADV_DATA_CB(cppc_get_cpu_power, cppc_get_cpu_cost); + + if (!efficiency_class_populated) + return; + + cpu_data = cppc_cpufreq_search_cpu_data(policy->cpu); + em_dev_register_perf_domain(get_cpu_device(policy->cpu), + get_perf_level_count(policy), &em_cb, + cpu_data->shared_cpu_map, 0); +} + #else static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu) @@ -471,6 +609,9 @@ static int populate_efficiency_class(void) { return 0; } +static void cppc_cpufreq_register_em(struct cpufreq_policy *policy) +{ +} #endif @@ -742,6 +883,7 @@ static struct cpufreq_driver cppc_cpufreq_driver = { .init = cppc_cpufreq_cpu_init, .exit = cppc_cpufreq_cpu_exit, .set_boost = cppc_cpufreq_set_boost, + .register_em = cppc_cpufreq_register_em, .attr = cppc_cpufreq_attr, .name = "cppc_cpufreq", };