From patchwork Tue Mar 4 15:23:26 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mario Limonciello X-Patchwork-Id: 870400 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 AD7ED283CBA; Tue, 4 Mar 2025 15:23:37 +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=1741101817; cv=none; b=GPvjwd8rkZRVkBrPAjD8I9noVMGGGefiq9sqRV7h+M+fUh8EhYYNvx0zNwuyeYQLvyh77M/bL86+SEAZeqNKx0xhm6opK1FZIrII7L1uHVtwJHgoJDEJAa5UVYpxhd/+1Dc1x9AY1f897yUt1FzZ8RS/bgr4D5cBw5ILnWr9iTc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741101817; c=relaxed/simple; bh=VymNDH1jT+gpaLwW2gldk72PJ+nc5piVYY5i4ZwV7dA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e82OytTxKbYbwuVjELiGauhfC/LCncC/VD0jHIiR7PvpeWhg2qwqHYt2ed5k0ubSdadbBLtI4sW0aR+wTIqzKTsSQSKO4yXSNCjl+yP7ubmAY1wo+sdKYf+RnNV0IL6q0yBZEaVDmCAQDyaa44g+4P244l4fkjGNqUUdZNGchaA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fxyBetpH; 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="fxyBetpH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBDE5C4CEE7; Tue, 4 Mar 2025 15:23:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741101817; bh=VymNDH1jT+gpaLwW2gldk72PJ+nc5piVYY5i4ZwV7dA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fxyBetpHB22VDtA1O0dhruAFFhtLwTWLk31jKstAqV9F5n3SPlaGos5T9vKGmLoPi 3733IqwMUxNBi68Y1CAlHnG4dks6kg7qhoFObRiShPD4djf77Rsq4SaWXoQMInQHhd lehz7Cz5C437qExf+YyxmXBG+nQrjdIXHeR2ukpM1QqvoIvY9uQbNrdKf0hRP2y+CB 9v1dLMquC0+h5JnY3Y+KA40UELaXc5ui7qwDecuGnzO/NtBrOI9gNRdvYlfGl1FIob 5O2AhFUG4L4xGndnGUI5HoRu4QHwb0wXY60rG3GYX+SWsVmoRmsPKy7KTS/zHdynhX AnwpcBbIBC1dg== 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 v2 4/5] cpufreq/amd-pstate: Add support for raw EPP writes Date: Tue, 4 Mar 2025 09:23:26 -0600 Message-ID: <20250304152327.1561017-5-superm1@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250304152327.1561017-1-superm1@kernel.org> References: <20250304152327.1561017-1-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 The energy performance preference field of the CPPC request MSR supports values from 0 to 255, but the strings only offer 4 values. The other values are useful for tuning the performance of some workloads. Add support for writing the raw energy performance preference value to the sysfs file. If the last value written was an integer then an integer will be returned. If the last value written was a string then a string will be returned. Signed-off-by: Mario Limonciello --- Documentation/admin-guide/pm/amd-pstate.rst | 16 +++++++++++----- drivers/cpufreq/amd-pstate.c | 11 +++++++++-- drivers/cpufreq/amd-pstate.h | 1 + 3 files changed, 21 insertions(+), 7 deletions(-) diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 36950fb6568c0..0e4d2e0aaeff7 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -280,16 +280,22 @@ A list of all the supported EPP preferences that could be used for These profiles represent different hints that are provided to the low-level firmware about the user's desired energy vs efficiency tradeoff. ``default`` represents the epp value is set by platform -firmware. This attribute is read-only. +firmware. ``custom`` designates that integer values 0-255 may be written +as well. This attribute is read-only. ``energy_performance_preference`` The current energy performance preference can be read from this attribute. and user can change current preference according to energy or performance needs -Please get all support profiles list from -``energy_performance_available_preferences`` attribute, all the profiles are -integer values defined between 0 to 255 when EPP feature is enabled by platform -firmware, but if the dynamic EPP feature is enabled, driver will block writes. +Coarse named profiles are available in the attribute +``energy_performance_available_preferences``. +Users can also write individual integer values between 0 to 255. +When EPP feature is enabled by platform firmware but if the dynamic EPP feature is +enabled, driver will ignore the written value. Lower epp values shift the bias +towards improved performance while a higher epp value shifts the bias towards +power-savings. The exact impact can change from one platform to the other. +If a valid integer was last written, then a number will be returned on future reads. +If a valid string was last written then a string will be returned on future reads. This attribute is read-write. ``boost`` diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 28c02edf6e40b..dcf6e36d693f8 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1314,6 +1314,7 @@ ssize_t store_energy_performance_preference(struct cpufreq_policy *policy, struct amd_cpudata *cpudata = policy->driver_data; char str_preference[21]; ssize_t ret; + bool raw_epp = FALSE; u8 epp; if (cpudata->dynamic_epp) { @@ -1330,6 +1331,7 @@ ssize_t store_energy_performance_preference(struct cpufreq_policy *policy, * matches an index in the energy_perf_strings array */ ret = kstrtou8(str_preference, 0, &epp); + raw_epp = !ret; if (ret) { ret = match_string(energy_perf_strings, -1, str_preference); if (ret < 0 || ret == EPP_INDEX_CUSTOM) @@ -1349,7 +1351,9 @@ ssize_t store_energy_performance_preference(struct cpufreq_policy *policy, if (ret) return ret; - return ret ? ret : count; + cpudata->raw_epp = raw_epp; + + return count; } EXPORT_SYMBOL_GPL(store_energy_performance_preference); @@ -1360,6 +1364,9 @@ ssize_t show_energy_performance_preference(struct cpufreq_policy *policy, char * epp = FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cpudata->cppc_req_cached); + if (cpudata->raw_epp) + return sysfs_emit(buf, "%u\n", epp); + switch (epp) { case AMD_CPPC_EPP_PERFORMANCE: preference = EPP_INDEX_PERFORMANCE; @@ -1374,7 +1381,7 @@ ssize_t show_energy_performance_preference(struct cpufreq_policy *policy, char * preference = EPP_INDEX_POWERSAVE; break; default: - return sysfs_emit(buf, "%u\n", epp); + return -EINVAL; } return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]); diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h index b4c5374762110..b6be2b8fbffbf 100644 --- a/drivers/cpufreq/amd-pstate.h +++ b/drivers/cpufreq/amd-pstate.h @@ -108,6 +108,7 @@ struct amd_cpudata { u8 epp_default_ac; u8 epp_default_dc; bool dynamic_epp; + bool raw_epp; struct notifier_block power_nb; /* platform profile */