Merge tag 'pm-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "Once again, the changes are dominated by cpufreq updates, but this
  time the majority of them are cpufreq core changes, mostly related to
  the introduction of policy locking guards and __free() usage, and
  fixes related to boost handling.

  Still, there is also a significant update of the intel_pstate driver
  making it register an energy model when running on a hybrid platform
  which is used for enabling energy-aware scheduling (EAS) if the driver
  operates in the passive mode (and schedutil is used as the cpufreq
  governor for all CPUs which is the passive mode default).

  There are some amd-pstate driver updates too, for a good measure,
  including the "Requested CPU Min frequency" BIOS option support and
  new online/offline callbacks.

  In the cpuidle space, the most significant change is the addition of a
  C1 demotion on/off sysfs knob to intel_idle which should help some
  users to configure their systems more precisely. There is also the
  conversion of the PSCI cpuidle driver to a faux device one and there
  are two small updates of cpuidle governors.

  Device power management is also modified quite a bit, especially the
  handling of devices with asynchronous suspend and resume enabled
  during system transitions. They are now going to be handled more
  asynchronously during suspend transitions and somewhat less
  aggressively during resume transitions.

  Apart from the above, the operating performance points (OPP) library
  is now going to use mutex locking guards and scope-based cleanup
  helpers and there is the usual bunch of assorted fixes and code
  cleanups.

  Specifics:

   - Fix potential division-by-zero error in em_compute_costs() (Yaxiong
     Tian)

   - Fix typos in energy model documentation and example driver code
     (Moon Hee Lee, Atul Kumar Pant)

   - Rearrange the energy model management code and add a new function
     for adjusting a CPU energy model after adjusting the capacity of
     the given CPU to it (Rafael Wysocki)

   - Refactor cpufreq_online(), add and use cpufreq policy locking
     guards, use __free() in policy reference counting, and clean up
     core cpufreq code on top of that (Rafael Wysocki)

   - Fix boost handling on CPU suspend/resume and sysfs updates (Viresh
     Kumar)

   - Fix des_perf clamping with max_perf in amd_pstate_update()
     (Dhananjay Ugwekar)

   - Add offline, online and suspend callbacks to the amd-pstate driver,
     rename and use the existing amd_pstate_epp callbacks in it
     (Dhananjay Ugwekar)

   - Add support for the "Requested CPU Min frequency" BIOS option to
     the amd-pstate driver (Dhananjay Ugwekar)

   - Reset amd-pstate driver mode after running selftests (Swapnil
     Sapkal)

   - Avoid shadowing ret in amd_pstate_ut_check_driver() (Nathan
     Chancellor)

   - Add helper for governor checks to the schedutil cpufreq governor
     and move cpufreq-specific EAS checks to cpufreq (Rafael Wysocki)

   - Populate the cpu_capacity sysfs entries from the intel_pstate
     driver after registering asym capacity support (Ricardo Neri)

   - Add support for enabling Energy-aware scheduling (EAS) to the
     intel_pstate driver when operating in the passive mode on a hybrid
     platform (Rafael Wysocki)

   - Drop redundant cpus_read_lock() from store_local_boost() in the
     cpufreq core (Seyediman Seyedarab)

   - Replace sscanf() with kstrtouint() in the cpufreq code and use a
     symbol instead of a raw number in it (Bowen Yu)

   - Add support for autonomous CPU performance state selection to the
     CPPC cpufreq driver (Lifeng Zheng)

   - OPP: Add dev_pm_opp_set_level() (Praveen Talari)

   - Introduce scope-based cleanup headers and mutex locking guards in
     OPP core (Viresh Kumar)

   - Switch OPP to use kmemdup_array() (Zhang Enpei)

   - Optimize bucket assignment when next_timer_ns equals KTIME_MAX in
     the menu cpuidle governor (Zhongqiu Han)

   - Convert the cpuidle PSCI driver to a faux device one (Sudeep Holla)

   - Add C1 demotion on/off sysfs knob to the intel_idle driver (Artem
     Bityutskiy)

   - Fix typos in two comments in the teo cpuidle governor (Atul Kumar
     Pant)

   - Fix denying of auto suspend in pm_suspend_timer_fn() (Charan Teja
     Kalla)

   - Move debug runtime PM attributes to runtime_attrs[] (Rafael
     Wysocki)

   - Add new devm_ functions for enabling runtime PM and runtime PM
     reference counting (Bence Csókás)

   - Remove size arguments from strscpy() calls in the hibernation core
     code (Thorsten Blum)

   - Adjust the handling of devices with asynchronous suspend enabled
     during system suspend and resume to start resuming them immediately
     after resuming their parents and to start suspending such a device
     immediately after suspending its first child (Rafael Wysocki)

   - Adjust messages printed during tasks freezing to avoid using
     pr_cont() (Andrew Sayers, Paul Menzel)

   - Clean up unnecessary usage of !! in pm_print_times_init() (Zihuan
     Zhang)

   - Add missing wakeup source attribute relax_count to sysfs and remove
     the space character at the end ofi the string produced by
     pm_show_wakelocks() (Zijun Hu)

   - Add configurable pm_test delay for hibernation (Zihuan Zhang)

   - Disable asynchronous suspend in ucsi_ccg_probe() to prevent the
     cypd4226 device on Tegra boards from suspending prematurely (Jon
     Hunter)

   - Unbreak printing PM debug messages during hibernation and clean up
     some related code (Rafael Wysocki)

   - Add a systemd service to run cpupower and change cpupower binding's
     Makefile to use -lcpupower (John B. Wyatt IV, Francesco Poli)"

* tag 'pm-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (72 commits)
  cpufreq: CPPC: Add support for autonomous selection
  cpufreq: Update sscanf() to kstrtouint()
  cpufreq: Replace magic number
  OPP: switch to use kmemdup_array()
  PM: freezer: Rewrite restarting tasks log to remove stray *done.*
  PM: runtime: fix denying of auto suspend in pm_suspend_timer_fn()
  cpufreq: drop redundant cpus_read_lock() from store_local_boost()
  cpupower: do not install files to /etc/default/
  cpupower: do not call systemctl at install time
  cpupower: do not write DESTDIR to cpupower.service
  PM: sleep: Introduce pm_sleep_transition_in_progress()
  cpufreq/amd-pstate: Avoid shadowing ret in amd_pstate_ut_check_driver()
  cpufreq: intel_pstate: Document hybrid processor support
  cpufreq: intel_pstate: EAS: Increase cost for CPUs using L3 cache
  cpufreq: intel_pstate: EAS support for hybrid platforms
  PM: EM: Introduce em_adjust_cpu_capacity()
  PM: EM: Move CPU capacity check to em_adjust_new_capacity()
  PM: EM: Documentation: Fix typos in example driver code
  cpufreq: Drop policy locking from cpufreq_policy_is_good_for_eas()
  PM: sleep: Introduce pm_suspend_in_progress()
  ...

5 files changed, 194 insertions, 7 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 7772d4f034d2..8a4d7ecf46ec 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -111,6 +111,7 @@ What:		/sys/devices/system/cpu/cpuidle/available_governors
 		/sys/devices/system/cpu/cpuidle/current_driver
 		/sys/devices/system/cpu/cpuidle/current_governor
 		/sys/devices/system/cpu/cpuidle/current_governer_ro
+		/sys/devices/system/cpu/cpuidle/intel_c1_demotion
 Date:		September 2007
 Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
 Description:	Discover cpuidle policy and mechanism
@@ -132,7 +133,11 @@ Description:	Discover cpuidle policy and mechanism
 
 		current_governor_ro: (RO) displays current idle policy.
 
-		See Documentation/admin-guide/pm/cpuidle.rst and
+		intel_c1_demotion: (RW) enables/disables the C1 demotion
+		feature on Intel CPUs.
+
+		See Documentation/admin-guide/pm/cpuidle.rst,
+		Documentation/admin-guide/pm/intel_idle.rst, and
 		Documentation/driver-api/pm/cpuidle.rst for more information.
 
 
@@ -268,6 +273,60 @@ Description:	Discover CPUs in the same CPU frequency coordination domain
 		This file is only present if the acpi-cpufreq or the cppc-cpufreq
 		drivers are in use.
 
+What:		/sys/devices/system/cpu/cpuX/cpufreq/auto_select
+Date:		May 2025
+Contact:	linux-pm@vger.kernel.org
+Description:	Autonomous selection enable
+
+		Read/write interface to control autonomous selection enable
+			Read returns autonomous selection status:
+				0: autonomous selection is disabled
+				1: autonomous selection is enabled
+
+			Write 'y' or '1' or 'on' to enable autonomous selection.
+			Write 'n' or '0' or 'off' to disable autonomous selection.
+
+		This file is only present if the cppc-cpufreq driver is in use.
+
+What:		/sys/devices/system/cpu/cpuX/cpufreq/auto_act_window
+Date:		May 2025
+Contact:	linux-pm@vger.kernel.org
+Description:	Autonomous activity window
+
+		This file indicates a moving utilization sensitivity window to
+		the platform's autonomous selection policy.
+
+		Read/write an integer represents autonomous activity window (in
+		microseconds) from/to this file. The max value to write is
+		1270000000 but the max significand is 127. This means that if 128
+		is written to this file, 127 will be stored. If the value is
+		greater than 130, only the first two digits will be saved as
+		significand.
+
+		Writing a zero value to this file enable the platform to
+		determine an appropriate Activity Window depending on the workload.
+
+		Writing to this file only has meaning when Autonomous Selection is
+		enabled.
+
+		This file is only present if the cppc-cpufreq driver is in use.
+
+What:		/sys/devices/system/cpu/cpuX/cpufreq/energy_performance_preference_val
+Date:		May 2025
+Contact:	linux-pm@vger.kernel.org
+Description:	Energy performance preference
+
+		Read/write an 8-bit integer from/to this file. This file
+		represents a range of values from 0 (performance preference) to
+		0xFF (energy efficiency preference) that influences the rate of
+		performance increase/decrease and the result of the hardware's
+		energy efficiency and performance optimization policies.
+
+		Writing to this file only has meaning when Autonomous Selection is
+		enabled.
+
+		This file is only present if the cppc-cpufreq driver is in use.
+
 
 What:		/sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
 Date:		August 2008
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1d6d39f4c68d..ea81784be981 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1828,6 +1828,13 @@
 				lz4: Select LZ4 compression algorithm to
 				compress/decompress hibernation image.
 
+	hibernate.pm_test_delay=
+			[HIBERNATION]
+			Sets the number of seconds to remain in a hibernation test
+			mode before resuming the system (see
+			/sys/power/pm_test). Only available when CONFIG_PM_DEBUG
+			is set. Default value is 5.
+
 	highmem=nn[KMG]	[KNL,BOOT,EARLY] forces the highmem zone to have an exact
 			size of <nn>. This works even on boxes that have no
 			highmem otherwise. This also works to reduce highmem
diff --git a/Documentation/admin-guide/pm/intel_idle.rst b/Documentation/admin-guide/pm/intel_idle.rst
index 5940528146eb..ed6f055d4b14 100644
--- a/Documentation/admin-guide/pm/intel_idle.rst
+++ b/Documentation/admin-guide/pm/intel_idle.rst
@@ -38,6 +38,27 @@ instruction at all.
 only way to pass early-configuration-time parameters to it is via the kernel
 command line.
 
+Sysfs Interface
+===============
+
+The ``intel_idle`` driver exposes the following ``sysfs`` attributes in
+``/sys/devices/system/cpu/cpuidle/``:
+
+``intel_c1_demotion``
+	Enable or disable C1 demotion for all CPUs in the system. This file is
+	only exposed on platforms that support the C1 demotion feature and where
+	it was tested. Value 0 means that C1 demotion is disabled, value 1 means
+	that it is enabled. Write 0 or 1 to disable or enable C1 demotion for
+	all CPUs.
+
+	The C1 demotion feature involves the platform firmware demoting deep
+	C-state requests from the OS (e.g., C6 requests) to C1. The idea is that
+	firmware monitors CPU wake-up rate, and if it is higher than a
+	platform-specific threshold, the firmware demotes deep C-state requests
+	to C1. For example, Linux requests C6, but firmware noticed too many
+	wake-ups per second, and it keeps the CPU in C1. When the CPU stays in
+	C1 long enough, the platform promotes it back to C6. This may improve
+	some workloads' performance, but it may also increase power consumption.
 
 .. _intel-idle-enumeration-of-states:
 
diff --git a/Documentation/admin-guide/pm/intel_pstate.rst b/Documentation/admin-guide/pm/intel_pstate.rst
index 78fc83ed2a7e..26e702c7016e 100644
--- a/Documentation/admin-guide/pm/intel_pstate.rst
+++ b/Documentation/admin-guide/pm/intel_pstate.rst
@@ -329,6 +329,106 @@ information listed above is the same for all of the processors supporting the
 HWP feature, which is why ``intel_pstate`` works with all of them.]
 
 
+Support for Hybrid Processors
+=============================
+
+Some processors supported by ``intel_pstate`` contain two or more types of CPU
+cores differing by the maximum turbo P-state, performance vs power characteristics,
+cache sizes, and possibly other properties.  They are commonly referred to as
+hybrid processors.  To support them, ``intel_pstate`` requires HWP to be enabled
+and it assumes the HWP performance units to be the same for all CPUs in the
+system, so a given HWP performance level always represents approximately the
+same physical performance regardless of the core (CPU) type.
+
+Hybrid Processors with SMT
+--------------------------
+
+On systems where SMT (Simultaneous Multithreading), also referred to as
+HyperThreading (HT) in the context of Intel processors, is enabled on at least
+one core, ``intel_pstate`` assigns performance-based priorities to CPUs.  Namely,
+the priority of a given CPU reflects its highest HWP performance level which
+causes the CPU scheduler to generally prefer more performant CPUs, so the less
+performant CPUs are used when the other ones are fully loaded.  However, SMT
+siblings (that is, logical CPUs sharing one physical core) are treated in a
+special way such that if one of them is in use, the effective priority of the
+other ones is lowered below the priorities of the CPUs located in the other
+physical cores.
+
+This approach maximizes performance in the majority of cases, but unfortunately
+it also leads to excessive energy usage in some important scenarios, like video
+playback, which is not generally desirable.  While there is no other viable
+choice with SMT enabled because the effective capacity and utilization of SMT
+siblings are hard to determine, hybrid processors without SMT can be handled in
+more energy-efficient ways.
+
+.. _CAS:
+
+Capacity-Aware Scheduling Support
+---------------------------------
+
+The capacity-aware scheduling (CAS) support in the CPU scheduler is enabled by
+``intel_pstate`` by default on hybrid processors without SMT.  CAS generally
+causes the scheduler to put tasks on a CPU so long as there is a sufficient
+amount of spare capacity on it, and if the utilization of a given task is too
+high for it, the task will need to go somewhere else.
+
+Since CAS takes CPU capacities into account, it does not require CPU
+prioritization and it allows tasks to be distributed more symmetrically among
+the more performant and less performant CPUs.  Once placed on a CPU with enough
+capacity to accommodate it, a task may just continue to run there regardless of
+whether or not the other CPUs are fully loaded, so on average CAS reduces the
+utilization of the more performant CPUs which causes the energy usage to be more
+balanced because the more performant CPUs are generally less energy-efficient
+than the less performant ones.
+
+In order to use CAS, the scheduler needs to know the capacity of each CPU in
+the system and it needs to be able to compute scale-invariant utilization of
+CPUs, so ``intel_pstate`` provides it with the requisite information.
+
+First of all, the capacity of each CPU is represented by the ratio of its highest
+HWP performance level, multiplied by 1024, to the highest HWP performance level
+of the most performant CPU in the system, which works because the HWP performance
+units are the same for all CPUs.  Second, the frequency-invariance computations,
+carried out by the scheduler to always express CPU utilization in the same units
+regardless of the frequency it is currently running at, are adjusted to take the
+CPU capacity into account.  All of this happens when ``intel_pstate`` has
+registered itself with the ``CPUFreq`` core and it has figured out that it is
+running on a hybrid processor without SMT.
+
+Energy-Aware Scheduling Support
+-------------------------------
+
+If ``CONFIG_ENERGY_MODEL`` has been set during kernel configuration and
+``intel_pstate`` runs on a hybrid processor without SMT, in addition to enabling
+`CAS <CAS_>`_ it registers an Energy Model for the processor.  This allows the
+Energy-Aware Scheduling (EAS) support to be enabled in the CPU scheduler if
+``schedutil`` is used as the  ``CPUFreq`` governor which requires ``intel_pstate``
+to operate in the `passive mode <Passive Mode_>`_.
+
+The Energy Model registered by ``intel_pstate`` is artificial (that is, it is
+based on abstract cost values and it does not include any real power numbers)
+and it is relatively simple to avoid unnecessary computations in the scheduler.
+There is a performance domain in it for every CPU in the system and the cost
+values for these performance domains have been chosen so that running a task on
+a less performant (small) CPU appears to be always cheaper than running that
+task on a more performant (big) CPU.  However, for two CPUs of the same type,
+the cost difference depends on their current utilization, and the CPU whose
+current utilization is higher generally appears to be a more expensive
+destination for a given task.  This helps to balance the load among CPUs of the
+same type.
+
+Since EAS works on top of CAS, high-utilization tasks are always migrated to
+CPUs with enough capacity to accommodate them, but thanks to EAS, low-utilization
+tasks tend to be placed on the CPUs that look less expensive to the scheduler.
+Effectively, this causes the less performant and less loaded CPUs to be
+preferred as long as they have enough spare capacity to run the given task
+which generally leads to reduced energy usage.
+
+The Energy Model created by ``intel_pstate`` can be inspected by looking at
+the ``energy_model`` directory in ``debugfs`` (typlically mounted on
+``/sys/kernel/debug/``).
+
+
 User Space Interface in ``sysfs``
 =================================
 
@@ -697,8 +797,8 @@ of them have to be prepended with the ``intel_pstate=`` prefix.
 	Limits`_ for details).
 
 ``no_cas``
-	Do not enable capacity-aware scheduling (CAS) which is enabled by
-	default on hybrid systems.
+	Do not enable `capacity-aware scheduling <CAS_>`_ which is enabled by
+	default on hybrid systems without SMT.
 
 Diagnostics and Tuning
 ======================
diff --git a/Documentation/power/energy-model.rst b/Documentation/power/energy-model.rst
index ada4938c37e5..cbdf7520aaa6 100644
--- a/Documentation/power/energy-model.rst
+++ b/Documentation/power/energy-model.rst
@@ -230,7 +230,7 @@ Drivers must provide a pointer to the allocated and initialized new EM
 and will be visible to other sub-systems in the kernel (thermal, powercap).
 The main design goal for this API is to be fast and avoid extra calculations
 or memory allocations at runtime. When pre-computed EMs are available in the
-device driver, than it should be possible to simply re-use them with low
+device driver, then it should be possible to simply reuse them with low
 performance overhead.
 
 In order to free the EM, provided earlier by the driver (e.g. when the module
@@ -381,17 +381,17 @@ up periodically to check the temperature and modify the EM data::
   26		rcu_read_unlock();
   27
   28		/* Calculate 'cost' values for EAS */
-  29		ret = em_dev_compute_costs(dev, table, pd->nr_perf_states);
+  29		ret = em_dev_compute_costs(dev, new_table, pd->nr_perf_states);
   30		if (ret) {
   31			dev_warn(dev, "EM: compute costs failed %d\n", ret);
-  32			em_free_table(em_table);
+  32			em_table_free(em_table);
   33			return;
   34		}
   35
   36		ret = em_dev_update_perf_domain(dev, em_table);
   37		if (ret) {
   38			dev_warn(dev, "EM: update failed %d\n", ret);
-  39			em_free_table(em_table);
+  39			em_table_free(em_table);
   40			return;
   41		}
   42