linux-stable.git/arch/x86/kernel/acpi/cppc.c, branch linux-rolling-stable

ACPI: CPPC: Detect preferred core availability on online CPUs

2025-11-24T09:37:32+00:00

[ Upstream commit 4fe5934db4a7187d358f1af1b3ef9b6dd59bce58 ]

Commit 279f838a61f9 ("x86/amd: Detect preferred cores in
amd_get_boost_ratio_numerator()") introduced the ability to detect the
preferred core on AMD platforms by checking if there at least two
distinct highest_perf values.

However, it uses for_each_present_cpu() to iterate through all the
CPUs in the platform, which is problematic when the kernel is booted
with "nosmt=force" commandline option.

Hence limit the search to only the online CPUs.

Fixes: 279f838a61f9 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()")
Reported-by: Christopher Harris 
Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_C4Cw@mail.gmail.com/
Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" 
Tested-by: Chrisopher Harris 
Signed-off-by: Gautham R. Shenoy 
Link: https://patch.msgid.link/20251107074145.2340-2-gautham.shenoy@amd.com
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

Merge branch 'x86/msr' into x86/core, to resolve conflicts

2025-05-13T08:42:06+00:00

 Conflicts:
	arch/x86/boot/startup/sme.c
	arch/x86/coco/sev/core.c
	arch/x86/kernel/fpu/core.c
	arch/x86/kernel/fpu/xstate.c

 Semantic conflict:
	arch/x86/include/asm/sev-internal.h

Signed-off-by: Ingo Molnar

x86/cpufeatures: Shorten X86_FEATURE_AMD_HETEROGENEOUS_CORES

2025-04-15T20:09:20+00:00

Shorten X86_FEATURE_AMD_HETEROGENEOUS_CORES to X86_FEATURE_AMD_HTR_CORES
to make the last column aligned consistently in the whole file.

No functional changes.

Suggested-by: Borislav Petkov (AMD) 
Signed-off-by: Xin Li (Intel) 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/20250415175410.2944032-4-xin@zytor.com

x86/msr: Rename 'wrmsrl_safe_on_cpu()' to 'wrmsrq_safe_on_cpu()'

2025-04-10T09:58:55+00:00

Suggested-by: "H. Peter Anvin" 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Cc: Juergen Gross 
Cc: Dave Hansen 
Cc: Xin Li 
Cc: Linus Torvalds

x86/msr: Rename 'rdmsrl_safe_on_cpu()' to 'rdmsrq_safe_on_cpu()'

2025-04-10T09:58:49+00:00

Suggested-by: "H. Peter Anvin" 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Cc: Juergen Gross 
Cc: Dave Hansen 
Cc: Xin Li 
Cc: Linus Torvalds

cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks

2025-03-06T19:01:25+00:00

Bitfield masks are easier to follow and less error prone.

Reviewed-by: Dhananjay Ugwekar 
Reviewed-by: Gautham R. Shenoy 
Signed-off-by: Mario Limonciello

Merge tag 'x86_cpu_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-11-19T20:27:19+00:00

Pull x86 cpuid updates from Borislav Petkov:

 - Add a feature flag which denotes AMD CPUs supporting workload
   classification with the purpose of using such hints when making
   scheduling decisions

 - Determine the boost enumerator for each AMD core based on its type:
   efficiency or performance, in the cppc driver

 - Add the type of a CPU to the topology CPU descriptor with the goal of
   supporting and making decisions based on the type of the respective
   core

 - Add a feature flag to denote AMD cores which have heterogeneous
   topology and enable SD_ASYM_PACKING for those

 - Check microcode revisions before disabling PCID on Intel

 - Cleanups and fixlets

* tag 'x86_cpu_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Remove redundant CONFIG_NUMA guard around numa_add_cpu()
  x86/cpu: Fix FAM5_QUARK_X1000 to use X86_MATCH_VFM()
  x86/cpu: Fix formatting of cpuid_bits[] in scattered.c
  x86/cpufeatures: Add X86_FEATURE_AMD_WORKLOAD_CLASS feature bit
  x86/amd: Use heterogeneous core topology for identifying boost numerator
  x86/cpu: Add CPU type to struct cpuinfo_topology
  x86/cpu: Enable SD_ASYM_PACKING for PKG domain on AMD
  x86/cpufeatures: Add X86_FEATURE_AMD_HETEROGENEOUS_CORES
  x86/cpufeatures: Rename X86_FEATURE_FAST_CPPC to have AMD prefix
  x86/mm: Don't disable PCID when INVLPG has been fixed by microcode

ACPI: processor: Move arch_init_invariance_cppc() call later

2024-11-06T20:31:36+00:00

arch_init_invariance_cppc() is called at the end of
acpi_cppc_processor_probe() in order to configure frequency invariance
based upon the values from _CPC.

This however doesn't work on AMD CPPC shared memory designs that have
AMD preferred cores enabled because _CPC needs to be analyzed from all
cores to judge if preferred cores are enabled.

This issue manifests to users as a warning since commit 21fb59ab4b97
("ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"):
```
Could not retrieve highest performance (-19)
```

However the warning isn't the cause of this, it was actually
commit 279f838a61f9 ("x86/amd: Detect preferred cores in
amd_get_boost_ratio_numerator()") which exposed the issue.

To fix this problem, change arch_init_invariance_cppc() into a new weak
symbol that is called at the end of acpi_processor_driver_init().
Each architecture that supports it can declare the symbol to override
the weak one.

Define it for x86, in arch/x86/kernel/acpi/cppc.c, and for all of the
architectures using the generic arch_topology.c code.

Fixes: 279f838a61f9 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()")
Reported-by: Ivan Shapovalov 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219431
Tested-by: Oleksandr Natalenko 
Signed-off-by: Mario Limonciello 
Link: https://patch.msgid.link/20241104222855.3959267-1-superm1@kernel.org
[ rjw: Changelog edit ]
Signed-off-by: Rafael J. Wysocki

x86/amd: Use heterogeneous core topology for identifying boost numerator

2024-10-25T18:51:17+00:00

AMD heterogeneous designs include two types of cores:

 * Performance
 * Efficiency

Each core type has different highest performance values configured by the
platform.  Drivers such as amd_pstate need to identify the type of core to
correctly set an appropriate boost numerator to calculate the maximum
frequency.

X86_FEATURE_AMD_HETEROGENEOUS_CORES is used to identify whether the SoC
supports heterogeneous core type by reading CPUID leaf Fn_0x80000026.

On performance cores the scaling factor of 196 is used.  On efficiency cores
the scaling factor is the value reported as the highest perf.  Efficiency
cores have the same preferred core rankings.

Suggested-by: Perry Yuan 
Signed-off-by: Mario Limonciello 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/r/20241025171459.1093-6-mario.limonciello@amd.com

cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()

2024-09-11T15:23:23+00:00

The special case in amd_pstate_highest_perf_set() is the value used
for calculating the boost numerator.  Merge this into
amd_get_boost_ratio_numerator() and then use that to calculate boost
ratio.

This allows dropping more special casing of the highest perf value.

Reviewed-by: Gautham R. Shenoy 
Signed-off-by: Mario Limonciello