Commit 5cdfedf6 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Merge tag 'amd-pstate-v7.1-2026-04-02' of... 

Merge tag 'amd-pstate-v7.1-2026-04-02' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux

Pull amd-pstate new content for 7.1 (2026-04-02) from Mario Limonciello:

"Add support for new features:
  * CPPC performance priority
  * Dynamic EPP
  * Raw EPP
  * New unit tests for new features
 Fixes for:
  * PREEMPT_RT
  * sysfs files being present when HW missing
  * Broken/outdated documentation"

* tag 'amd-pstate-v7.1-2026-04-02' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux: (22 commits)
  MAINTAINERS: amd-pstate: Step down as maintainer, add Prateek as reviewer
  cpufreq: Pass the policy to cpufreq_driver->adjust_perf()
  cpufreq/amd-pstate: Pass the policy to amd_pstate_update()
  cpufreq/amd-pstate-ut: Add a unit test for raw EPP
  cpufreq/amd-pstate: Add support for raw EPP writes
  cpufreq/amd-pstate: Add support for platform profile class
  cpufreq/amd-pstate: add kernel command line to override dynamic epp
  cpufreq/amd-pstate: Add dynamic energy performance preference
  Documentation: amd-pstate: fix dead links in the reference section
  cpufreq/amd-pstate: Cache the max frequency in cpudata
  Documentation/amd-pstate: Add documentation for amd_pstate_floor_{freq,count}
  Documentation/amd-pstate: List amd_pstate_prefcore_ranking sysfs file
  Documentation/amd-pstate: List amd_pstate_hw_prefcore sysfs file
  amd-pstate-ut: Add a testcase to validate the visibility of driver attributes
  amd-pstate-ut: Add module parameter to select testcases
  amd-pstate: Introduce a tracepoint trace_amd_pstate_cppc_req2()
  amd-pstate: Add sysfs support for floor_freq and floor_count
  amd-pstate: Add support for CPPC_REQ2 and FLOOR_PERF
  x86/cpufeatures: Add AMD CPPC Performance Priority feature.
  amd-pstate: Make certain freq_attrs conditionally visible
  ...
parents 35ed8fa0 9487e2a0

Documentation/admin-guide/kernel-parameters.txt

+7 −0
Original line number Diff line number Diff line
@@ -493,6 +493,13 @@ Kernel parameters 
			disable

			  Disable amd-pstate preferred core.



	amd_dynamic_epp=

			[X86]

			disable

			  Disable amd-pstate dynamic EPP.

			enable

			  Enable amd-pstate dynamic EPP.



	amijoy.map=	[HW,JOY] Amiga joystick support

			Map of devices attached to JOY0DAT and JOY1DAT

			Format: <a>,<b>

Documentation/admin-guide/pm/amd-pstate.rst

+77 −10
Original line number Diff line number Diff line
@@ -239,8 +239,12 @@ control its functionality at the system level. They are located in the 


 root@hr-test1:/home/ray# ls /sys/devices/system/cpu/cpufreq/policy0/*amd*

 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_highest_perf

 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_hw_prefcore

 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_lowest_nonlinear_freq

 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_max_freq

 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_floor_freq

 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_floor_count

 /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_prefcore_ranking





``amd_pstate_highest_perf / amd_pstate_max_freq``
@@ -264,14 +268,46 @@ This attribute is read-only. 


``amd_pstate_hw_prefcore``



Whether the platform supports the preferred core feature and it has been

enabled. This attribute is read-only.

Whether the platform supports the preferred core feature and it has

been enabled. This attribute is read-only. This file is only visible

on platforms which support the preferred core feature.



``amd_pstate_prefcore_ranking``



The performance ranking of the core. This number doesn't have any unit, but

larger numbers are preferred at the time of reading. This can change at

runtime based on platform conditions. This attribute is read-only.

runtime based on platform conditions. This attribute is read-only. This file

is only visible on platforms which support the preferred core feature.



``amd_pstate_floor_freq``



The floor frequency associated with each CPU. Userspace can write any

value between ``cpuinfo_min_freq`` and ``scaling_max_freq`` into this

file. When the system is under power or thermal constraints, the

platform firmware will attempt to throttle the CPU frequency to the

value specified in ``amd_pstate_floor_freq`` before throttling it

further. This allows userspace to specify different floor frequencies

to different CPUs. For optimal results, threads of the same core

should have the same floor frequency value. This file is only visible

on platforms that support the CPPC Performance Priority feature.





``amd_pstate_floor_count``



The number of distinct Floor Performance levels supported by the

platform. For example, if this value is 2, then the number of unique

values obtained from the command ``cat

/sys/devices/system/cpu/cpufreq/policy*/amd_pstate_floor_freq |

sort -n | uniq`` should be at most this number for the behavior

described in ``amd_pstate_floor_freq`` to take effect. A zero value

implies that the platform supports unlimited floor performance levels.

This file is only visible on platforms that support the CPPC

Performance Priority feature.



**Note**: When ``amd_pstate_floor_count`` is non-zero, the frequency to

which the CPU is throttled under power or thermal constraints is

undefined when the number of unique values of ``amd_pstate_floor_freq``

across all CPUs in the system exceeds ``amd_pstate_floor_count``.



``energy_performance_available_preferences``
@@ -280,16 +316,22 @@ 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, if EPP feature is disabled, driver will ignore the written value

Coarse named profiles are available in the attribute

``energy_performance_available_preferences``.

Users can also write individual integer values between 0 to 255.

When dynamic EPP is enabled, writes to energy_performance_preference are blocked

even when EPP feature is enabled by platform firmware. 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``
@@ -311,6 +353,24 @@ boost or `1` to enable it, for the respective CPU using the sysfs path 
Other performance and frequency values can be read back from

``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`.



Dynamic energy performance profile

==================================

The amd-pstate driver supports dynamically selecting the energy performance

profile based on whether the machine is running on AC or DC power.



Whether this behavior is enabled by default depends on the kernel

config option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`. This behavior can also be overridden

at runtime by the sysfs file ``/sys/devices/system/cpu/cpufreq/policyX/dynamic_epp``.



When set to enabled, the driver will select a different energy performance

profile when the machine is running on battery or AC power. The driver will

also register with the platform profile handler to receive notifications of

user desired power state and react to those.

When set to disabled, the driver will not change the energy performance profile

based on the power source and will not react to user desired power state.



Attempting to manually write to the ``energy_performance_preference`` sysfs

file will fail when ``dynamic_epp`` is enabled.



``amd-pstate`` vs ``acpi-cpufreq``

======================================
@@ -422,6 +482,13 @@ For systems that support ``amd-pstate`` preferred core, the core rankings will 
always be advertised by the platform. But OS can choose to ignore that via the

kernel parameter ``amd_prefcore=disable``.



``amd_dynamic_epp``



When AMD pstate is in auto mode, dynamic EPP will control whether the kernel

autonomously changes the EPP mode. The default is configured by

``CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`` but can be explicitly enabled with

``amd_dynamic_epp=enable`` or disabled with ``amd_dynamic_epp=disable``.



User Space Interface in ``sysfs`` - General

===========================================
@@ -790,13 +857,13 @@ Reference 
===========



.. [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming,

       https://www.amd.com/system/files/TechDocs/24593.pdf

       https://docs.amd.com/v/u/en-US/24593_3.44_APM_Vol2



.. [2] Advanced Configuration and Power Interface Specification,

       https://uefi.org/sites/default/files/resources/ACPI_Spec_6_4_Jan22.pdf



.. [3] Processor Programming Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors

       https://www.amd.com/system/files/TechDocs/56569-A1-PUB.zip

       https://docs.amd.com/v/u/en-US/56569-A1-PUB_3.03



.. [4] Linux Kernel Selftests,

       https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html

MAINTAINERS

+1 −1
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@@ -1234,9 +1234,9 @@ F: drivers/gpu/drm/amd/pm/ 








AMD PSTATE DRIVER









M:	Huang Rui <ray.huang@amd.com>









M:	Gautham R. Shenoy <gautham.shenoy@amd.com>









M:	Mario Limonciello <mario.limonciello@amd.com>









R:	Perry Yuan <perry.yuan@amd.com>









R:	K Prateek Nayak <kprateek.nayak@amd.com>









L:	linux-pm@vger.kernel.org









S:	Supported









F:	Documentation/admin-guide/pm/amd-pstate.rst
































arch/x86/include/asm/cpufeatures.h



+1
−1






























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@@ -415,7 +415,7 @@







 */









#define X86_FEATURE_OVERFLOW_RECOV	(17*32+ 0) /* "overflow_recov" MCA overflow recovery support */









#define X86_FEATURE_SUCCOR		(17*32+ 1) /* "succor" Uncorrectable error containment and recovery */



















#define X86_FEATURE_CPPC_PERF_PRIO	(17*32+ 2) /* CPPC Floor Perf support */









#define X86_FEATURE_SMCA		(17*32+ 3) /* "smca" Scalable MCA */



















/* Intel-defined CPU features, CPUID level 0x00000007:0 (EDX), word 18 */
































arch/x86/include/asm/msr-index.h



+5
−0






























Original line number
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@@ -765,12 +765,14 @@







#define MSR_AMD_CPPC_CAP2		0xc00102b2









#define MSR_AMD_CPPC_REQ		0xc00102b3









#define MSR_AMD_CPPC_STATUS		0xc00102b4









#define MSR_AMD_CPPC_REQ2		0xc00102b5



















/* Masks for use with MSR_AMD_CPPC_CAP1 */









#define AMD_CPPC_LOWEST_PERF_MASK	GENMASK(7, 0)









#define AMD_CPPC_LOWNONLIN_PERF_MASK	GENMASK(15, 8)









#define AMD_CPPC_NOMINAL_PERF_MASK	GENMASK(23, 16)









#define AMD_CPPC_HIGHEST_PERF_MASK	GENMASK(31, 24)









#define AMD_CPPC_FLOOR_PERF_CNT_MASK	GENMASK_ULL(39, 32)



















/* Masks for use with MSR_AMD_CPPC_REQ */









#define AMD_CPPC_MAX_PERF_MASK		GENMASK(7, 0)








@@ -778,6 +780,9 @@







#define AMD_CPPC_DES_PERF_MASK		GENMASK(23, 16)









#define AMD_CPPC_EPP_PERF_MASK		GENMASK(31, 24)



















/* Masks for use with MSR_AMD_CPPC_REQ2 */









#define AMD_CPPC_FLOOR_PERF_MASK	GENMASK(7, 0)



















/* AMD Performance Counter Global Status and Control MSRs */









#define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS	0xc0000300









#define MSR_AMD64_PERF_CNTR_GLOBAL_CTL		0xc0000301