commit 40d8abf364bcab23bc715a9221a3c8623956257b upstream.

If the NumEntries field in the _CPC return package is less than 2, do
not attempt to access the "Revision" element of that package, because
it may not be present then.

Fixes: 337aadff8e45 ("ACPI: Introduce CPU performance controls using CPPC")
BugLink: https://lore.kernel.org/lkml/20220322143534.GC32582@xsang-OptiPlex-9020/
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The ret_val local variable in cpc_read() is not necessary, so
eliminate it.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Huang Rui <ray.huang@amd.com>

The code as currently implemented does not work on big endian systems,
so fix it up.

Fixes: a2c8f92bea5f ("ACPI: CPPC: Implement support for SystemIO registers")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/linux-acpi/20220111092928.GA24968@kili/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Huang Rui <ray.huang@amd.com>

Pull power management updates from Rafael Wysocki:
 "The most signigicant change here is the addition of a new cpufreq
  'P-state' driver for AMD processors as a better replacement for the
  venerable acpi-cpufreq driver.

  There are also other cpufreq updates (in the core, intel_pstate, ARM
  drivers), PM core updates (mostly related to adding new macros for
  declaring PM operations which should make the lives of driver
  developers somewhat easier), and a bunch of assorted fixes and
  cleanups.

  Summary:

   - Add new P-state driver for AMD processors (Huang Rui).

   - Fix initialization of min and max frequency QoS requests in the
     cpufreq core (Rafael Wysocki).

   - Fix EPP handling on Alder Lake in intel_pstate (Srinivas
     Pandruvada).

   - Make intel_pstate update cpuinfo.max_freq when notified of HWP
     capabilities changes and drop a redundant function call from that
     driver (Rafael Wysocki).

   - Improve IRQ support in the Qcom cpufreq driver (Ard Biesheuvel,
     Stephen Boyd, Vladimir Zapolskiy).

   - Fix double devm_remap() in the Mediatek cpufreq driver (Hector
     Yuan).

   - Introduce thermal pressure helpers for cpufreq CPU cooling (Lukasz
     Luba).

   - Make cpufreq use default_groups in kobj_type (Greg Kroah-Hartman).

   - Make cpuidle use default_groups in kobj_type (Greg Kroah-Hartman).

   - Fix two comments in cpuidle code (Jason Wang, Yang Li).

   - Allow model-specific normal EPB value to be used in the intel_epb
     sysfs attribute handling code (Srinivas Pandruvada).

   - Simplify locking in pm_runtime_put_suppliers() (Rafael Wysocki).

   - Add safety net to supplier device release in the runtime PM core
     code (Rafael Wysocki).

   - Capture device status before disabling runtime PM for it (Rafael
     Wysocki).

   - Add new macros for declaring PM operations to allow drivers to
     avoid guarding them with CONFIG_PM #ifdefs or __maybe_unused and
     update some drivers to use these macros (Paul Cercueil).

   - Allow ACPI hardware signature to be honoured during restore from
     hibernation (David Woodhouse).

   - Update outdated operating performance points (OPP) documentation
     (Tang Yizhou).

   - Reduce log severity for informative message regarding frequency
     transition failures in devfreq (Tzung-Bi Shih).

   - Add DRAM frequency controller devfreq driver for Allwinner sunXi
     SoCs (Samuel Holland).

   - Add missing COMMON_CLK dependency to sun8i devfreq driver (Arnd
     Bergmann).

   - Add support for new layout of Psys PowerLimit Register on SPR to
     the Intel RAPL power capping driver (Zhang Rui).

   - Fix typo in a comment in idle_inject.c (Jason Wang).

   - Remove unused function definition from the DTPM (Dynamit Thermal
     Power Management) power capping framework (Daniel Lezcano).

   - Reduce DTPM trace verbosity (Daniel Lezcano)"

* tag 'pm-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits)
  x86, sched: Fix undefined reference to init_freq_invariance_cppc() build error
  cpufreq: amd-pstate: Fix Kconfig dependencies for AMD P-State
  cpufreq: amd-pstate: Fix struct amd_cpudata kernel-doc comment
  cpuidle: use default_groups in kobj_type
  x86: intel_epb: Allow model specific normal EPB value
  MAINTAINERS: Add AMD P-State driver maintainer entry
  Documentation: amd-pstate: Add AMD P-State driver introduction
  cpufreq: amd-pstate: Add AMD P-State performance attributes
  cpufreq: amd-pstate: Add AMD P-State frequencies attributes
  cpufreq: amd-pstate: Add boost mode support for AMD P-State
  cpufreq: amd-pstate: Add trace for AMD P-State module
  cpufreq: amd-pstate: Introduce the support for the processors with shared memory solution
  cpufreq: amd-pstate: Add fast switch function for AMD P-State
  cpufreq: amd-pstate: Introduce a new AMD P-State driver to support future processors
  ACPI: CPPC: Add CPPC enable register function
  ACPI: CPPC: Check present CPUs for determining _CPC is valid
  ACPI: CPPC: Implement support for SystemIO registers
  x86/msr: Add AMD CPPC MSR definitions
  x86/cpufeatures: Add AMD Collaborative Processor Performance Control feature flag
  cpufreq: use default_groups in kobj_type
  ...

Merge ACPI tables parsing code update, NUMA-related ACPI update, CPPC
documentation update, ACPI sysfs attributes handling update and ACPI
thermal and battery drivers updates for 5.17-rc1:

 - Add AEST to the list of known ACPI table signatures (Shuuichirou
   Ishii).

 - Make ACPI NUMA code take hotpluggable memblocks into account when
   CONFIG_MEMORY_HOTPLUG is not set (Vitaly Kuznetsov).

 - Use default_groups in kobj_type in the ACPI sysfs code (Greg
   Kroah-Hartman).

 - Rearrange _CPC structure documentation (Andy Shevchenko).

 - Drop an always true check from the ACPI thermal driver (Adam
   Borowski).

 - Add new "not charging" quirk for Lenovo ThinkPads to the ACPI
   battery driver (Thomas Weißschuh).

* acpi-tables:
  ACPI: tables: Add AEST to the list of known table signatures

* acpi-numa:
  ACPI: NUMA: Process hotpluggable memblocks when !CONFIG_MEMORY_HOTPLUG

* acpi-sysfs:
  ACPI: sysfs: use default_groups in kobj_type

* acpi-cppc:
  ACPI: CPPC: Amend documentation in the comments

* acpi-thermal:
  ACPI: thermal: drop an always true check

* acpi-battery:
  ACPI: battery: Add the ThinkPad "Not Charging" quirk

Add a new function to enable CPPC feature. This function
will write Continuous Performance Control package
EnableRegister field on the processor.

CPPC EnableRegister register described in section 8.4.7.1 of ACPI 6.4:
This element is optional. If supported, contains a resource descriptor
with a single Register() descriptor that describes a register to which
OSPM writes a One to enable CPPC on this processor. Before this register
is set, the processor will be controlled by legacy mechanisms (ACPI
Pstates, firmware, etc.).

This register will be used for AMD processors to enable AMD P-State
function instead of legacy ACPI P-States.

Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

As this is a static check, it should be based upon what is currently
present on the system. This makes probeing more deterministic.

While local APIC flags field (lapic_flags) of cpu core in MADT table is
0, then the cpu core won't be enabled. In this case, _CPC won't be found
in this core, and return back to _CPC invalid with walking through
possible cpus (include disable cpus). This is not expected, so switch to
check present CPUs instead.

Reported-by: Jinzhou Su <Jinzhou.Su@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

According to the ACPI v6.2 (and later) specification, SystemIO can be
used for _CPC registers. This teaches cppc_acpi how to handle such
registers.

This patch was tested using the amd_pstate driver on my Zephyrus G15
(model GA503QS) using the current version 410 BIOS, which uses
a SystemIO register for the HighestPerformance element in _CPC.

Signed-off-by: Steven Noonan <steven@valvesoftware.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field.  Move the ACPI sysfs code to use default_groups field which has
been the preferred way since aa30f47cf666 ("kobject: Add support for
default attribute groups to kobj_type") so that we can soon get rid of
the obsolete default_attrs field.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently it's too hard to read the _CPC structure as it's commented.
Reshuffle indentation and style to make it readable.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>