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  * Broken/outdated documentation"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
  ...

Author: rafaeljw

Documentation/admin-guide/kernel-parameters.txt

@@ -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

@@ -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

@@ -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

@@ -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

@@ -765,19 +765,24 @@
 #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)
 #define AMD_CPPC_MIN_PERF_MASK		GENMASK(15, 8)
 #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

arch/x86/kernel/cpu/scattered.c

@@ -52,6 +52,7 @@ static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_CPB,			CPUID_EDX,  9, 0x80000007, 0 },
 	{ X86_FEATURE_PROC_FEEDBACK,		CPUID_EDX, 11, 0x80000007, 0 },
 	{ X86_FEATURE_AMD_FAST_CPPC,		CPUID_EDX, 15, 0x80000007, 0 },
+	{ X86_FEATURE_CPPC_PERF_PRIO,		CPUID_EDX, 16, 0x80000007, 0 },
 	{ X86_FEATURE_MBA,			CPUID_EBX,  6, 0x80000008, 0 },
 	{ X86_FEATURE_X2AVIC_EXT,		CPUID_ECX,  6, 0x8000000a, 0 },
 	{ X86_FEATURE_COHERENCY_SFW_NO,		CPUID_EBX, 31, 0x8000001f, 0 },

drivers/cpufreq/Kconfig.x86

@@ -40,6 +40,7 @@ config X86_AMD_PSTATE
 	select ACPI_PROCESSOR
 	select ACPI_CPPC_LIB if X86_64
 	select CPU_FREQ_GOV_SCHEDUTIL if SMP
+	select ACPI_PLATFORM_PROFILE
 	help
 	  This driver adds a CPUFreq driver which utilizes a fine grain
 	  processor performance frequency control range instead of legacy
@@ -68,6 +69,18 @@ config X86_AMD_PSTATE_DEFAULT_MODE
 	  For details, take a look at:
 	  <file:Documentation/admin-guide/pm/amd-pstate.rst>.
 
+config X86_AMD_PSTATE_DYNAMIC_EPP
+	bool "AMD Processor P-State dynamic EPP support"
+	depends on X86_AMD_PSTATE
+	default n
+	help
+	  Allow the kernel to dynamically change the energy performance
+	  value from events like ACPI platform profile and AC adapter plug
+	  events.
+
+	  This feature can also be changed at runtime, this configuration
+	  option only sets the kernel default value behavior.
+
 config X86_AMD_PSTATE_UT
 	tristate "selftest for AMD Processor P-State driver"
 	depends on X86 && ACPI_PROCESSOR

drivers/cpufreq/amd-pstate-trace.h

@@ -133,6 +133,41 @@ TRACE_EVENT(amd_pstate_epp_perf,
 		 )
 );
 
+TRACE_EVENT(amd_pstate_cppc_req2,
+
+	TP_PROTO(unsigned int cpu_id,
+		 u8 floor_perf,
+		 bool changed,
+		 int err_code
+		 ),
+
+	TP_ARGS(cpu_id,
+		floor_perf,
+		changed,
+		err_code),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, cpu_id)
+		__field(u8, floor_perf)
+		__field(bool, changed)
+		__field(int, err_code)
+		),
+
+	TP_fast_assign(
+		__entry->cpu_id = cpu_id;
+		__entry->floor_perf = floor_perf;
+		__entry->changed = changed;
+		__entry->err_code = err_code;
+		),
+
+	TP_printk("cpu%u: floor_perf=%u, changed=%u (error = %d)",
+		  __entry->cpu_id,
+		  __entry->floor_perf,
+		  __entry->changed,
+		  __entry->err_code
+		 )
+);
+
 #endif /* _AMD_PSTATE_TRACE_H */
 
 /* This part must be outside protection */