Merge branch 'pm-cpufreq'

Merge cpufreq changes for 6.9-rc1:

 - Enable preferred core support in the amd-pstate cpufreq driver (Meng
   Li).

 - Fix min_perf assignment in amd_pstate_adjust_perf() and make the
   min/max limit perf values in amd-pstate always stay within the
   (highest perf, lowest perf) range (Tor Vic, Meng Li).

 - Change default transition delay in cpufreq to 2ms (Qais Yousef).

 - Drop long-unused cpudata::prev_cummulative_iowait from the
   intel_pstate cpufreq driver (Jiri Slaby).

 - Allow intel_pstate to assign model-specific values to strings used in
   the EPP sysfs interface and make it do so on Meteor Lake (Srinivas
   Pandruvada).

 - Remove references to 10ms minimum sampling rate from comments in the
   cpufreq code (Pierre Gondois).

 - Prevent scaling_cur_freq from exceeding scaling_max_freq when the
   latter is an inefficient frequency (Shivnandan Kumar).

 - Honour transition_latency over transition_delay_us in cpufreq (Qais
   Yousef).

 - Stop unregistering cpufreq cooling on CPU hot-remove (Viresh Kumar).

 - General enhancements / cleanups to ARM cpufreq drivers (tianyu2,
   Nícolas F. R. A. Prado, Erick Archer, Arnd Bergmann, Anastasia
   Belova).

 - Update cpufreq-dt-platdev to block/approve devices (Richard Acayan).

 - Make the SCMI cpufreq driver get a transition delay value from
   firmware (Pierre Gondois).

* pm-cpufreq: (28 commits)
  cpufreq: scmi: Set transition_delay_us
  firmware: arm_scmi: Populate fast channel rate_limit
  firmware: arm_scmi: Populate perf commands rate_limit
  cpufreq: Don't unregister cpufreq cooling on CPU hotplug
  cpufreq: Honour transition_latency over transition_delay_us
  cpufreq: Limit resolving a frequency to policy min/max
  cpufreq: amd-pstate: adjust min/max limit perf
  cpufreq: Remove references to 10ms min sampling rate
  cpufreq: intel_pstate: Update default EPPs for Meteor Lake
  cpufreq: intel_pstate: Allow model specific EPPs
  cpufreq: qcom-hw: add CONFIG_COMMON_CLK dependency
  cpufreq: dt-platdev: block SDM670 in cpufreq-dt-platdev
  cpufreq: intel_pstate: remove cpudata::prev_cummulative_iowait
  cpufreq: Change default transition delay to 2ms
  cpufreq: amd-pstate: Fix min_perf assignment in amd_pstate_adjust_perf()
  Documentation: PM: amd-pstate: Fix section title underline
  Documentation: introduce amd-pstate preferrd core mode kernel command line options
  Documentation: amd-pstate: introduce amd-pstate preferred core
  cpufreq: amd-pstate: Update amd-pstate preferred core ranking dynamically
  ACPI: cpufreq: Add highest perf change notification
  ...

4 files changed, 64 insertions, 4 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 8f7fb911b2cc2..e0f51ebdb225c 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -374,6 +374,11 @@
 			  selects a performance level in this range and appropriate
 			  to the current workload.
 
+	amd_prefcore=
+			[X86]
+			disable
+			  Disable amd-pstate preferred core.
+
 	amijoy.map=	[HW,JOY] Amiga joystick support
 			Map of devices attached to JOY0DAT and JOY1DAT
 			Format: <a>,<b>
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 9eb26014d34b6..1e0d101b020a0 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -300,8 +300,8 @@ platforms. The AMD P-States mechanism is the more performance and energy
 efficiency frequency management method on AMD processors.
 
 
-AMD Pstate Driver Operation Modes
-=================================
+``amd-pstate`` Driver Operation Modes
+======================================
 
 ``amd_pstate`` CPPC has 3 operation modes: autonomous (active) mode,
 non-autonomous (passive) mode and guided autonomous (guided) mode.
@@ -353,6 +353,48 @@ 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.
 
+``amd-pstate`` Preferred Core
+=================================
+
+The core frequency is subjected to the process variation in semiconductors.
+Not all cores are able to reach the maximum frequency respecting the
+infrastructure limits. Consequently, AMD has redefined the concept of
+maximum frequency of a part. This means that a fraction of cores can reach
+maximum frequency. To find the best process scheduling policy for a given
+scenario, OS needs to know the core ordering informed by the platform through
+highest performance capability register of the CPPC interface.
+
+``amd-pstate`` preferred core enables the scheduler to prefer scheduling on
+cores that can achieve a higher frequency with lower voltage. The preferred
+core rankings can dynamically change based on the workload, platform conditions,
+thermals and ageing.
+
+The priority metric will be initialized by the ``amd-pstate`` driver. The ``amd-pstate``
+driver will also determine whether or not ``amd-pstate`` preferred core is
+supported by the platform.
+
+``amd-pstate`` driver will provide an initial core ordering when the system boots.
+The platform uses the CPPC interfaces to communicate the core ranking to the
+operating system and scheduler to make sure that OS is choosing the cores
+with highest performance firstly for scheduling the process. When ``amd-pstate``
+driver receives a message with the highest performance change, it will
+update the core ranking and set the cpu's priority.
+
+``amd-pstate`` Preferred Core Switch
+=====================================
+Kernel Parameters
+-----------------
+
+``amd-pstate`` peferred core`` has two states: enable and disable.
+Enable/disable states can be chosen by different kernel parameters.
+Default enable ``amd-pstate`` preferred core.
+
+``amd_prefcore=disable``
+
+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``.
+
 User Space Interface in ``sysfs`` - General
 ===========================================
 
@@ -385,6 +427,19 @@ control its functionality at the system level.  They are located in the
         to the operation mode represented by that string - or to be
         unregistered in the "disable" case.
 
+``prefcore``
+	Preferred core state of the driver: "enabled" or "disabled".
+
+	"enabled"
+		Enable the ``amd-pstate`` preferred core.
+
+	"disabled"
+		Disable the ``amd-pstate`` preferred core
+
+
+        This attribute is read-only to check the state of preferred core set
+        by the kernel parameter.
+
 ``cpupower`` tool support for ``amd-pstate``
 ===============================================
 
diff --git a/Documentation/power/opp.rst b/Documentation/power/opp.rst
index a7c03c4709807..1b7f1d854f14a 100644
--- a/Documentation/power/opp.rst
+++ b/Documentation/power/opp.rst
@@ -305,7 +305,7 @@ dev_pm_opp_get_opp_count
 	 {
 		/* Do things */
 		num_available = dev_pm_opp_get_opp_count(dev);
-		speeds = kzalloc(sizeof(u32) * num_available, GFP_KERNEL);
+		speeds = kcalloc(num_available, sizeof(u32), GFP_KERNEL);
 		/* populate the table in increasing order */
 		freq = 0;
 		while (!IS_ERR(opp = dev_pm_opp_find_freq_ceil(dev, &freq))) {
diff --git a/Documentation/translations/zh_CN/power/opp.rst b/Documentation/translations/zh_CN/power/opp.rst
index 8d6e3f6f62024..7470fa2d4c43a 100644
--- a/Documentation/translations/zh_CN/power/opp.rst
+++ b/Documentation/translations/zh_CN/power/opp.rst
@@ -274,7 +274,7 @@ dev_pm_opp_get_opp_count
 	 {
 		/* 做一些事情 */
 		num_available = dev_pm_opp_get_opp_count(dev);
-		speeds = kzalloc(sizeof(u32) * num_available, GFP_KERNEL);
+		speeds = kcalloc(num_available, sizeof(u32), GFP_KERNEL);
 		/* 按升序填充表 */
 		freq = 0;
 		while (!IS_ERR(opp = dev_pm_opp_find_freq_ceil(dev, &freq))) {