linux.git/drivers/acpi/cppc_acpi.c, branch v6.18.21 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git ACPI: CPPC: Fix remaining for_each_possible_cpu() to use online CPUs 2026-02-26T22:59:36+00:00 Sean V Kelley skelley@nvidia.com 2026-02-11T21:22:54+00:00 02978747e90722651fb887116f55fd5710e59067 [ Upstream commit 56eb0c0ed345da7815274aa821a8546a073d7e97 ] per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() --> acpi_cppc_processor_probe(). However, send_pcc_cmd() and acpi_get_psd_map() still iterate over all possible CPUs. In acpi_get_psd_map(), encountering an offline CPU returns -EFAULT, causing cppc_cpufreq initialization to fail. This breaks systems booted with "nosmt" or "nosmt=force". Fix by using for_each_online_cpu() in both functions. Fixes: 80b8286aeec0 ("ACPI / CPPC: support for batching CPPC requests") Signed-off-by: Sean V Kelley <skelley@nvidia.com> Link: https://patch.msgid.link/20260211212254.30190-1-skelley@nvidia.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 56eb0c0ed345da7815274aa821a8546a073d7e97 ]

per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online
CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() -->
acpi_cppc_processor_probe().

However, send_pcc_cmd() and acpi_get_psd_map() still iterate over all
possible CPUs. In acpi_get_psd_map(), encountering an offline CPU
returns -EFAULT, causing cppc_cpufreq initialization to fail.

This breaks systems booted with "nosmt" or "nosmt=force".

Fix by using for_each_online_cpu() in both functions.

Fixes: 80b8286aeec0 ("ACPI / CPPC: support for batching CPPC requests")
Signed-off-by: Sean V Kelley <skelley@nvidia.com>
Link: https://patch.msgid.link/20260211212254.30190-1-skelley@nvidia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ACPI: CPPC: Fix missing PCC check for guaranteed_perf 2026-01-02T11:56:57+00:00 Pengjie Zhang zhangpengjie2@huawei.com 2025-12-10T13:22:27+00:00 7e086c97dd2b746cbbfb813d73ba91d6c270bdb4 commit 6ea3a44cef28add2d93b1ef119d84886cb1e3c9b upstream. The current implementation overlooks the 'guaranteed_perf' register in this check. If the Guaranteed Performance register is located in the PCC subspace, the function currently attempts to read it without acquiring the lock and without sending the CMD_READ doorbell to the firmware. This can result in reading stale data. Fixes: 29523f095397 ("ACPI / CPPC: Add support for guaranteed performance") Signed-off-by: Pengjie Zhang <zhangpengjie2@huawei.com> Cc: 4.20+ <stable@vger.kernel.org> # 4.20+ [ rjw: Subject and changelog edits ] Link: https://patch.msgid.link/20251210132227.1988380-1-zhangpengjie2@huawei.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6ea3a44cef28add2d93b1ef119d84886cb1e3c9b upstream.

The current implementation overlooks the 'guaranteed_perf'
register in this check.

If the Guaranteed Performance register is located in the PCC
subspace, the function currently attempts to read it without
acquiring the lock and without sending the CMD_READ doorbell
to the firmware. This can result in reading stale data.

Fixes: 29523f095397 ("ACPI / CPPC: Add support for guaranteed performance")
Signed-off-by: Pengjie Zhang <zhangpengjie2@huawei.com>
Cc: 4.20+ <stable@vger.kernel.org> # 4.20+
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/20251210132227.1988380-1-zhangpengjie2@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACPI: CPPC: Limit perf ctrs in PCC check only to online CPUs 2025-11-07T17:37:42+00:00 Gautham R. Shenoy gautham.shenoy@amd.com 2025-11-07T07:41:44+00:00 0fce75870666b46b700cfbd3216380b422f975da per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online CPU via acpi_soft_cpu_online() --> __acpi_processor_start() --> acpi_cppc_processor_probe(). However the function cppc_perf_ctrs_in_pcc() checks if the CPPC perf-ctrs are in a PCC region for all the present CPUs, which breaks when the kernel is booted with "nosmt=force". Hence, limit the check only to the online CPUs. Fixes: ae2df912d1a5 ("ACPI: CPPC: Disable FIE if registers in PCC regions") Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org> Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Link: https://patch.msgid.link/20251107074145.2340-5-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online
CPU via acpi_soft_cpu_online() --> __acpi_processor_start() -->
acpi_cppc_processor_probe().

However the function cppc_perf_ctrs_in_pcc() checks if the CPPC
perf-ctrs are in a PCC region for all the present CPUs, which breaks
when the kernel is booted with "nosmt=force".

Hence, limit the check only to the online CPUs.

Fixes: ae2df912d1a5 ("ACPI: CPPC: Disable FIE if registers in PCC regions")
Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://patch.msgid.link/20251107074145.2340-5-gautham.shenoy@amd.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: CPPC: Perform fast check switch only for online CPUs 2025-11-07T17:37:42+00:00 Gautham R. Shenoy gautham.shenoy@amd.com 2025-11-07T07:41:43+00:00 8821c8e80a65bc4eb73daf63b34aac6b8ad69461 per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() --> acpi_cppc_processor_probe(). However the function cppc_allow_fast_switch() checks for the validity of the _CPC object for all the present CPUs. This breaks when the kernel is booted with "nosmt=force". Check fast_switch capability only on online CPUs Fixes: 15eece6c5b05 ("ACPI: CPPC: Fix NULL pointer dereference when nosmp is used") Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org> Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Link: https://patch.msgid.link/20251107074145.2340-4-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online
CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() -->
acpi_cppc_processor_probe().

However the function cppc_allow_fast_switch() checks for the validity
of the _CPC object for all the present CPUs. This breaks when the
kernel is booted with "nosmt=force".

Check fast_switch capability only on online CPUs

Fixes: 15eece6c5b05 ("ACPI: CPPC: Fix NULL pointer dereference when nosmp is used")
Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://patch.msgid.link/20251107074145.2340-4-gautham.shenoy@amd.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: CPPC: Check _CPC validity for only the online CPUs 2025-11-07T17:37:42+00:00 Gautham R. Shenoy gautham.shenoy@amd.com 2025-11-07T07:41:42+00:00 6dd3b8a709a130a4d55c866af9804c81b8486d28 per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() --> acpi_cppc_processor_probe(). However the function acpi_cpc_valid() checks for the validity of the _CPC object for all the present CPUs. This breaks when the kernel is booted with "nosmt=force". Hence check the validity of the _CPC objects of only the online CPUs. Fixes: 2aeca6bd0277 ("ACPI: CPPC: Check present CPUs for determining _CPC is valid") Reported-by: Christopher Harris <chris.harris79@gmail.com> Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_C4Cw@mail.gmail.com/ Suggested-by: Mario Limonciello <mario.limonciello@amd.com> Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org> Tested-by: Chrisopher Harris <chris.harris79@gmail.com> Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Link: https://patch.msgid.link/20251107074145.2340-3-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online
CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() -->
acpi_cppc_processor_probe().

However the function acpi_cpc_valid() checks for the validity of the
_CPC object for all the present CPUs. This breaks when the kernel is
booted with "nosmt=force".

Hence check the validity of the _CPC objects of only the online CPUs.

Fixes: 2aeca6bd0277 ("ACPI: CPPC: Check present CPUs for determining _CPC is valid")
Reported-by: Christopher Harris <chris.harris79@gmail.com>
Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_C4Cw@mail.gmail.com/
Suggested-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org>
Tested-by: Chrisopher Harris <chris.harris79@gmail.com>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://patch.msgid.link/20251107074145.2340-3-gautham.shenoy@amd.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: CPPC: Fix typo in a comment 2025-11-03T16:25:42+00:00 Chu Guangqing chuguangqing@inspur.com 2025-10-31T05:52:40+00:00 1642fabff19f768e9a8fea85d55a2d6d43ecffe3 Fix spelling from "pachage" to "package". Signed-off-by: Chu Guangqing <chuguangqing@inspur.com> [ rjw: Changelog and subject edits ] Link: https://patch.msgid.link/20251031055240.2791-1-chuguangqing@inspur.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Fix spelling from "pachage" to "package".

Signed-off-by: Chu Guangqing <chuguangqing@inspur.com>
[ rjw: Changelog and subject edits ]
Link: https://patch.msgid.link/20251031055240.2791-1-chuguangqing@inspur.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: CPPC: Do not use CPUFREQ_ETERNAL as an error value 2025-10-01T11:57:13+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2025-09-26T10:29:50+00:00 c28a280bd465690981099cd6e43dfcfa5c28b133 Instead of using CPUFREQ_ETERNAL for signaling an error condition in cppc_get_transition_latency(), change the return value type of that function to int and make it return a proper negative error code on failures. No intentional functional impact. Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Qais Yousef <qyousef@layalina.io> 
Instead of using CPUFREQ_ETERNAL for signaling an error condition
in cppc_get_transition_latency(), change the return value type of
that function to int and make it return a proper negative error
code on failures.

No intentional functional impact.

Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
ACPI: CPPC: Fix NULL pointer dereference when nosmp is used 2025-06-10T18:52:50+00:00 Yunhui Cui cuiyunhui@bytedance.com 2025-06-04T02:30:36+00:00 15eece6c5b05e5f9db0711978c3e3b7f1a2cfe12 With nosmp in cmdline, other CPUs are not brought up, leaving their cpc_desc_ptr NULL. CPU0's iteration via for_each_possible_cpu() dereferences these NULL pointers, causing panic. Panic backtrace: [ 0.401123] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8 ... [ 0.403255] [<ffffffff809a5818>] cppc_allow_fast_switch+0x6a/0xd4 ... Kernel panic - not syncing: Attempted to kill init! Fixes: 3cc30dd00a58 ("cpufreq: CPPC: Enable fast_switch") Reported-by: Xu Lu <luxu.kernel@bytedance.com> Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://patch.msgid.link/20250604023036.99553-1-cuiyunhui@bytedance.com [ rjw: New subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
With nosmp in cmdline, other CPUs are not brought up, leaving
their cpc_desc_ptr NULL. CPU0's iteration via for_each_possible_cpu()
dereferences these NULL pointers, causing panic.

Panic backtrace:

[    0.401123] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8
...
[    0.403255] [<ffffffff809a5818>] cppc_allow_fast_switch+0x6a/0xd4
...
Kernel panic - not syncing: Attempted to kill init!

Fixes: 3cc30dd00a58 ("cpufreq: CPPC: Enable fast_switch")
Reported-by: Xu Lu <luxu.kernel@bytedance.com>
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Link: https://patch.msgid.link/20250604023036.99553-1-cuiyunhui@bytedance.com
[ rjw: New subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: CPPC: Add three functions related to autonomous selection 2025-04-30T20:01:31+00:00 Lifeng Zheng zhenglifeng1@huawei.com 2025-04-11T09:38:55+00:00 f35e5b3ccfd3516bc36b08e101678b036309397c cppc_set_epp() - write energy performance preference register value, based on ACPI 6.5, s8.4.6.1.7 cppc_get_auto_act_window() - read autonomous activity window register value, based on ACPI 6.5, s8.4.6.1.6 cppc_set_auto_act_window() - write autonomous activity window register value, based on ACPI 6.5, s8.4.6.1.6 Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Link: https://patch.msgid.link/20250411093855.982491-9-zhenglifeng1@huawei.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
cppc_set_epp() - write energy performance preference register value,
based on ACPI 6.5, s8.4.6.1.7

cppc_get_auto_act_window() - read autonomous activity window register
value, based on ACPI 6.5, s8.4.6.1.6

cppc_set_auto_act_window() - write autonomous activity window register
value, based on ACPI 6.5, s8.4.6.1.6

Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20250411093855.982491-9-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: CPPC: Modify cppc_get_auto_sel_caps() to cppc_get_auto_sel() 2025-04-30T20:01:31+00:00 Lifeng Zheng zhenglifeng1@huawei.com 2025-04-11T09:38:54+00:00 2605e4ab6615ef43361b18fc6d08dd884896aad8 Modify cppc_get_auto_sel_caps() to cppc_get_auto_sel(). Using a cppc_perf_caps to carry the value is unnecessary. Add a check to ensure the pointer 'enable' is not null. Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Link: https://patch.msgid.link/20250411093855.982491-8-zhenglifeng1@huawei.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Modify cppc_get_auto_sel_caps() to cppc_get_auto_sel(). Using a
cppc_perf_caps to carry the value is unnecessary.

Add a check to ensure the pointer 'enable' is not null.

Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20250411093855.982491-8-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>