From patchwork Wed Feb 19 21:02:48 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mario Limonciello X-Patchwork-Id: 866656 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0BE8E2566E4; Wed, 19 Feb 2025 21:03:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739999002; cv=none; b=mWpRVuSGrYLv6CxROusicv3egvFQ0G+28q91EXCeBrNLVGdzCcxXE1mGz/DuL9S/Gpe+GdQFawPSFLdwfvMkUWKovKr/oRxdGdMrBnnxRQFmwlO10J9x4ma3WMznbOzKyNakuu9rzBUOxhr6PEpUz7Dhd4gdVBAb8d9I4Ui210o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739999002; c=relaxed/simple; bh=6tdRCHYYbUcSAoAig+/AynHxVZA9IBeICBlSn2tn6wc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YyS2qY1Etc/yI62Ae3hbsJf5Nw69Qd0LxCh9/66P2aodE4YSqSAtYPkr3NWPZlYf+ZQjZAL/Pj37qdHodSezbLmn2uqFWy5fwSc9hujX05ZfTF+un1GWQDtPwC0hAzafao90CRhx8YVriKKmOeXR7hhwVAUO4iQ4p6q87TtEYIY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WIAuUmP/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WIAuUmP/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F468C4CEE6; Wed, 19 Feb 2025 21:03:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739999001; bh=6tdRCHYYbUcSAoAig+/AynHxVZA9IBeICBlSn2tn6wc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WIAuUmP/Y7RvUjfcazKiX46BGvaz/kocBDuDQCwxcQFD0SFnC4T3wofiI8W8VD0Yo FLl+XHyLsya34aFLh1TNhZD1tgf7Hz/FA6Qrq6oA7eoQE1SrtxVBdBfK141t5tcvbL xhlNkOFQy82VRuIL7UUFkcMlZatNnquAn2XdykviYzZxOx0NwcaGYxnAJZ/O7wNmXw bQA7wprGA9KautazrvBtmwLgfEU4bnvClWgoFUtXdKgdplDVCP+98YZo6D1X4ZgFtK 1LrWKuCiMcZ4XHBf7TL45a1PmkOIMUYTDBvSXchbicxNBydxDKDlTrDcVK5GeZMmDK AszvnGZ+Jp1HQ== From: Mario Limonciello To: "Gautham R . Shenoy" , Perry Yuan Cc: Dhananjay Ugwekar , linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)), linux-pm@vger.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK), Mario Limonciello Subject: [PATCH v4 05/19] cpufreq/amd-pstate: Overhaul locking Date: Wed, 19 Feb 2025 15:02:48 -0600 Message-ID: <20250219210302.442954-6-superm1@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250219210302.442954-1-superm1@kernel.org> References: <20250219210302.442954-1-superm1@kernel.org> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Mario Limonciello amd_pstate_cpu_boost_update() and refresh_frequency_limits() both update the policy state and have nothing to do with the amd-pstate driver itself. A global "limits" lock doesn't make sense because each CPU can have policies changed independently. Each time a CPU changes values they will atomically be written to the per-CPU perf member. Drop per CPU locking cases. The remaining "global" driver lock is used to ensure that only one entity can change driver modes at a given time. Reviewed-by: Gautham R. Shenoy Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index a6066fb4ffb63..85e3daddb56e0 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -196,7 +196,6 @@ static inline int get_mode_idx_from_str(const char *str, size_t size) return -EINVAL; } -static DEFINE_MUTEX(amd_pstate_limits_lock); static DEFINE_MUTEX(amd_pstate_driver_lock); static u8 msr_get_epp(struct amd_cpudata *cpudata) @@ -752,7 +751,6 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state) pr_err("Boost mode is not supported by this processor or SBIOS\n"); return -EOPNOTSUPP; } - guard(mutex)(&amd_pstate_driver_lock); ret = amd_pstate_cpu_boost_update(policy, state); refresh_frequency_limits(policy); @@ -1175,8 +1173,6 @@ static ssize_t store_energy_performance_preference( if (ret < 0) return -EINVAL; - guard(mutex)(&amd_pstate_limits_lock); - ret = amd_pstate_set_energy_pref_index(policy, ret); return ret ? ret : count; @@ -1349,8 +1345,10 @@ int amd_pstate_update_status(const char *buf, size_t size) if (mode_idx < 0 || mode_idx >= AMD_PSTATE_MAX) return -EINVAL; - if (mode_state_machine[cppc_state][mode_idx]) + if (mode_state_machine[cppc_state][mode_idx]) { + guard(mutex)(&amd_pstate_driver_lock); return mode_state_machine[cppc_state][mode_idx](mode_idx); + } return 0; } @@ -1371,7 +1369,6 @@ static ssize_t status_store(struct device *a, struct device_attribute *b, char *p = memchr(buf, '\n', count); int ret; - guard(mutex)(&amd_pstate_driver_lock); ret = amd_pstate_update_status(buf, p ? p - buf : count); return ret < 0 ? ret : count; @@ -1643,8 +1640,6 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy) if (cpudata->suspended) return 0; - guard(mutex)(&amd_pstate_limits_lock); - if (trace_amd_pstate_epp_perf_enabled()) { trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf, AMD_CPPC_EPP_BALANCE_POWERSAVE, @@ -1684,8 +1679,6 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy) struct amd_cpudata *cpudata = policy->driver_data; if (cpudata->suspended) { - guard(mutex)(&amd_pstate_limits_lock); - /* enable amd pstate from suspend state*/ amd_pstate_epp_reenable(policy);