From patchwork Tue Jan 21 08:44:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Beata Michalska X-Patchwork-Id: 13945949 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4EEDC1B4228; Tue, 21 Jan 2025 08:44:59 +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=1737449101; cv=none; b=UrWxB8uxd7cFQo08lmmHjGgSTeUt54bm2DTMqTeQcKeD6MadtMKmguqBCarjIm6r8DI5bUqP4C/EmoxSsze/8HB6vGOZ37J2HhGM8SJKh4HjAMvc9IPg3uQh1ij/HIsPOECzLaaSKrERt8fcEv2T2JY+Ns45rdDuEcwW2JeqCY4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737449101; c=relaxed/simple; bh=1d3O42Z/OFMK7IOkVt8miHaVZTIyGZmxXrTjBTXpyOQ=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=pSuuibShVWetziBJ4giOIuxHq+I4RVY2/wyo0s8hIRbuBD7XjEuw+pUAhkdHkCj/ydEepze9JBNphthbJTcsZPCwQZRqPU+9rfniSytsuwWdk9EyQEQmlwNLS2sr7W0IRO/otQ4lfNK9TnVaZIeR1Ytc5atX9y8ht9QpDIfArCA= 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 C5D5A106F; Tue, 21 Jan 2025 00:45:26 -0800 (PST) Received: from e125905.cambridge.arm.com (e125905.cambridge.arm.com [10.1.194.73]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id AB4A03F66E; Tue, 21 Jan 2025 00:44:54 -0800 (PST) From: Beata Michalska To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, ionela.voinescu@arm.com, sudeep.holla@arm.com, will@kernel.org, catalin.marinas@arm.com, rafael@kernel.org, viresh.kumar@linaro.org Cc: sumitg@nvidia.com, yang@os.amperecomputing.com, vanshikonda@os.amperecomputing.com, lihuisong@huawei.com, zhanjie9@hisilicon.com, Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H . Peter Anvin" , Phil Auld , x86@kernel.org, linux-doc@vger.kernel.org Subject: [PATCH v9 0/5] Add support for AArch64 AMUv1-based average freq Date: Tue, 21 Jan 2025 08:44:30 +0000 Message-Id: <20250121084435.2839280-1-beata.michalska@arm.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Hi All, This series adds support for obtaining an average CPU frequency based on a hardware provided feedback. The average frequency is being exposed via dedicated yet optional cpufreq sysfs attribute - cpuinfo_avg_freq. The architecture specific bits are being provided for AArch64, caching on existing implementation for FIE and AMUv1 support: the frequency scale factor, updated on each sched tick, serving as a base for retrieving the frequency for a given CPU, representing an average frequency reported between the ticks. The changes have been rather lightly (due to some limitations) tested on an FVP model. Note that [PATCH 2/4] arm64: amu: Delay allocating cpumask for AMU FIE support can be merged independently. Additionally, this series depends on [6] Relevant discussions: [1] https://lore.kernel.org/all/20240229162520.970986-1-vanshikonda@os.amperecomputing.com/ [2] https://lore.kernel.org/all/7eozim2xnepacnnkzxlbx34hib4otycnbn4dqymfziqou5lw5u@5xzpv3t7sxo3/ [3] https://lore.kernel.org/all/20231212072617.14756-1-lihuisong@huawei.com/ [4] https://lore.kernel.org/lkml/ZIHpd6unkOtYVEqP@e120325.cambridge.arm.com/T/#m4e74cb5a0aaa353c60fedc6cfb95ab7a6e381e3c [5] https://lore.kernel.org/all/20240603081331.3829278-1-beata.michalska@arm.com/ [6] https://lore.kernel.org/all/20240827154818.1195849-1-ionela.voinescu@arm.com/ v9: - Moved changes to arch_freq_get_on_cpu to a separate patch v8: - Drop introducing new function and reuse arch_freq_get_on_cpu, guarding its use in scaling_cur_freq sysfs handler with dedicated config for x86 v7: - Dropping 'arch_topology: init capacity_freq_ref to 0' patch from the series as this one has been sent separately as an independent change [https://lore.kernel.org/all/20240827154818.1195849-1-ionela.voinescu@arm.com/] - Including in the series change that introduces new sysfs entry [PATCH 1/4] - Consequently modifying previously arch_freq_get_on_cpu to match reqs for new sysfs attribute - Dropping an idea of considering a CPU that has been idle for a while as a valid source of information for obtaining an AMU-counter based frequency - Some minor cosmetic changes v6: - delay allocating cpumask for AMU FIE support instead of invalidating the mask upon failure to register cpufreq policy notifications - drop the change to cpufreq core (for cpuinfo_cur_freq) as this one will be sent as a separate change v5: - Fix invalid access to cpumask - Reworked finding reference cpu when getting the freq v4: - dropping seqcount - fixing identifying active cpu within given policy - skipping full dynticks cpus when retrieving the freq - bringing back plugging in arch_freq_get_on_cpu into cpuinfo_cur_freq v3: - dropping changes to cpufreq_verify_current_freq - pulling in changes from Ionela initializing capacity_freq_ref to 0 (thanks for that!) and applying suggestions made by her during last review: - switching to arch_scale_freq_capacity and arch_scale_freq_ref when reversing freq scale factor computation - swapping shift with multiplication - adding time limit for considering last scale update as valid - updating frequency scale factor upon entering idle v2: - Splitting the patches - Adding comment for full dyntick mode - Plugging arch_freq_get_on_cpu into cpufreq_verify_current_freq instead of in show_cpuinfo_cur_freq to allow the framework to stay more in sync with potential freq changes CC: Jonathan Corbet CC: Thomas Gleixner CC: Ingo Molnar CC: Borislav Petkov CC: Dave Hansen CC: H. Peter Anvin CC: Phil Auld CC: x86@kernel.org CC: linux-doc@vger.kernel.org *** BLURB HERE *** Beata Michalska (5): cpufreq: Allow arch_freq_get_on_cpu to return an error cpufreq: Introduce an optional cpuinfo_avg_freq sysfs entry arm64: amu: Delay allocating cpumask for AMU FIE support arm64: Provide an AMU-based version of arch_freq_get_on_cpu arm64: Update AMU-based freq scale factor on entering idle Documentation/admin-guide/pm/cpufreq.rst | 16 ++- arch/arm64/kernel/topology.c | 144 +++++++++++++++++++---- arch/x86/kernel/cpu/aperfmperf.c | 2 +- arch/x86/kernel/cpu/proc.c | 7 +- drivers/cpufreq/Kconfig.x86 | 12 ++ drivers/cpufreq/cpufreq.c | 38 +++++- include/linux/cpufreq.h | 2 +- 7 files changed, 189 insertions(+), 32 deletions(-)