From 3e6e078057640751654bda9fd2278a944f61fa4a Mon Sep 17 00:00:00 2001 From: Wyes Karny Date: Tue, 7 Mar 2023 11:27:37 +0000 Subject: Documentation: cpufreq: amd-pstate: Move amd_pstate param to alphabetical order Move amd_pstate command line param description to correct alphabetical order. Acked-by: Huang Rui Reviewed-by: Mario Limonciello Tested-by: Oleksandr Natalenko Signed-off-by: Wyes Karny Signed-off-by: Rafael J. Wysocki --- Documentation/admin-guide/kernel-parameters.txt | 35 +++++++++++++------------ 1 file changed, 18 insertions(+), 17 deletions(-) (limited to 'Documentation/admin-guide') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6221a1d057dd..1e38f3ae0e62 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -339,6 +339,24 @@ This mode requires kvm-amd.avic=1. (Default when IOMMU HW support is present.) + amd_pstate= [X86] + disable + Do not enable amd_pstate as the default + scaling driver for the supported processors + passive + Use amd_pstate as a scaling driver, driver requests a + desired performance on this abstract scale and the power + management firmware translates the requests into actual + hardware states (core frequency, data fabric and memory + clocks etc.) + active + Use amd_pstate_epp driver instance as the scaling driver, + driver provides a hint to the hardware if software wants + to bias toward performance (0x0) or energy efficiency (0xff) + to the CPPC firmware. then CPPC power algorithm will + calculate the runtime workload and adjust the realtime cores + frequency. + amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: , @@ -7059,20 +7077,3 @@ xmon commands. off xmon is disabled. - amd_pstate= [X86] - disable - Do not enable amd_pstate as the default - scaling driver for the supported processors - passive - Use amd_pstate as a scaling driver, driver requests a - desired performance on this abstract scale and the power - management firmware translates the requests into actual - hardware states (core frequency, data fabric and memory - clocks etc.) - active - Use amd_pstate_epp driver instance as the scaling driver, - driver provides a hint to the hardware if software wants - to bias toward performance (0x0) or energy efficiency (0xff) - to the CPPC firmware. then CPPC power algorithm will - calculate the runtime workload and adjust the realtime cores - frequency. -- cgit v1.2.3 From 2dd6d0ebf74049256160a3d03dabbd92fe0b8599 Mon Sep 17 00:00:00 2001 From: Wyes Karny Date: Tue, 7 Mar 2023 11:27:38 +0000 Subject: cpufreq: amd-pstate: Add guided autonomous mode From ACPI spec below 3 modes for CPPC can be defined: 1. Non autonomous: OS scaling governor specifies operating frequency/ performance level through `Desired Performance` register and platform follows that. 2. Guided autonomous: OS scaling governor specifies min and max frequencies/ performance levels through `Minimum Performance` and `Maximum Performance` register, and platform can autonomously select an operating frequency in this range. 3. Fully autonomous: OS only hints (via EPP) to platform for the required energy performance preference for the workload and platform autonomously scales the frequency. Currently (1) is supported by amd_pstate as passive mode, and (3) is implemented by EPP support. This change is to support (2). In guided autonomous mode the min_perf is based on the input from the scaling governor. For example, in case of schedutil this value depends on the current utilization. And max_perf is set to max capacity. To activate guided auto mode ``amd_pstate=guided`` command line parameter has to be passed in the kernel. Acked-by: Huang Rui Reviewed-by: Mario Limonciello Tested-by: Oleksandr Natalenko Signed-off-by: Wyes Karny Signed-off-by: Rafael J. Wysocki --- Documentation/admin-guide/kernel-parameters.txt | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'Documentation/admin-guide') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1e38f3ae0e62..1e5fe4891dd7 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -344,11 +344,11 @@ Do not enable amd_pstate as the default scaling driver for the supported processors passive - Use amd_pstate as a scaling driver, driver requests a - desired performance on this abstract scale and the power - management firmware translates the requests into actual - hardware states (core frequency, data fabric and memory - clocks etc.) + Use amd_pstate with passive mode as a scaling driver. + In this mode autonomous selection is disabled. + Driver requests a desired performance level and platform + tries to match the same performance level if it is + satisfied by guaranteed performance level. active Use amd_pstate_epp driver instance as the scaling driver, driver provides a hint to the hardware if software wants @@ -356,6 +356,11 @@ to the CPPC firmware. then CPPC power algorithm will calculate the runtime workload and adjust the realtime cores frequency. + guided + Activate guided autonomous mode. Driver requests minimum and + maximum performance level and the platform autonomously + selects a performance level in this range and appropriate + to the current workload. amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT -- cgit v1.2.3 From 7a9dec665f6875f61fe0c2e71b25842daade5110 Mon Sep 17 00:00:00 2001 From: Wyes Karny Date: Tue, 7 Mar 2023 11:27:40 +0000 Subject: Documentation: cpufreq: amd-pstate: Update amd_pstate status sysfs for guided Update amd_pstate status sysfs for guided mode. Acked-by: Huang Rui Reviewed-by: Bagas Sanjaya Reviewed-by: Mario Limonciello Tested-by: Oleksandr Natalenko Signed-off-by: Wyes Karny Signed-off-by: Rafael J. Wysocki --- Documentation/admin-guide/pm/amd-pstate.rst | 31 ++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'Documentation/admin-guide') diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 6e5298b521b1..1cf40f69278c 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -303,13 +303,18 @@ efficiency frequency management method on AMD processors. AMD Pstate Driver Operation Modes ================================= -``amd_pstate`` CPPC has two operation modes: CPPC Autonomous(active) mode and -CPPC non-autonomous(passive) mode. -active mode and passive mode can be chosen by different kernel parameters. -When in Autonomous mode, CPPC ignores requests done in the Desired Performance -Target register and takes into account only the values set to the Minimum requested -performance, Maximum requested performance, and Energy Performance Preference -registers. When Autonomous is disabled, it only considers the Desired Performance Target. +``amd_pstate`` CPPC has 3 operation modes: autonomous (active) mode, +non-autonomous (passive) mode and guided autonomous (guided) mode. +Active/passive/guided mode can be chosen by different kernel parameters. + +- In autonomous mode, platform ignores the desired performance level request + and takes into account only the values set to the minimum, maximum and energy + performance preference registers. +- In non-autonomous mode, platform gets desired performance level + from OS directly through Desired Performance Register. +- In guided-autonomous mode, platform sets operating performance level + autonomously according to the current workload and within the limits set by + OS through min and max performance registers. Active Mode ------------ @@ -338,6 +343,15 @@ to the Performance Reduction Tolerance register. Above the nominal performance l processor must provide at least nominal performance requested and go higher if current operating conditions allow. +Guided Mode +----------- + +``amd_pstate=guided`` + +If ``amd_pstate=guided`` is passed to kernel command line option then this mode +is activated. In this mode, driver requests minimum and maximum performance +level and the platform autonomously selects a performance level in this range +and appropriate to the current workload. User Space Interface in ``sysfs`` - General =========================================== @@ -358,6 +372,9 @@ control its functionality at the system level. They are located in the "passive" The driver is functional and in the ``passive mode`` + "guided" + The driver is functional and in the ``guided mode`` + "disable" The driver is unregistered and not functional now. -- cgit v1.2.3