linux.git/drivers/cpufreq/cppc_cpufreq.c, branch v6.12.80 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay 2025-10-23T14:20:26+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2025-10-18T16:13:41+00:00 24883bfe09c504922ff7602dce9786ec15237028 [ Upstream commit f965d111e68f4a993cc44d487d416e3d954eea11 ] If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a failure to retrieve the transition latency value from the platform firmware, the CPPC cpufreq driver will use that value (converted to microseconds) as the policy transition delay, but it is way too large for any practical use. Address this by making the driver use the cpufreq's default transition latency value (in microseconds) as the transition delay if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency(). Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us") Cc: 5.19+ <stable@vger.kernel.org> # 5.19 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f965d111e68f4a993cc44d487d416e3d954eea11 ]

If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a
failure to retrieve the transition latency value from the platform
firmware, the CPPC cpufreq driver will use that value (converted to
microseconds) as the policy transition delay, but it is way too large
for any practical use.

Address this by making the driver use the cpufreq's default
transition latency value (in microseconds) as the transition delay
if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency().

Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us")
Cc: 5.19+ <stable@vger.kernel.org> # 5.19
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: CPPC: Mark driver with NEED_UPDATE_LIMITS flag 2025-08-20T16:30:21+00:00 Prashant Malani pmalani@google.com 2025-07-22T05:55:40+00:00 31c0205923d9fbeb691e7bf5ca27152d99a131f7 [ Upstream commit 0a1416a49e63c320f6e6c1c8d07e1b58c0d4a3f3 ] AMU counters on certain CPPC-based platforms tend to yield inaccurate delivered performance measurements on systems that are idle/mostly idle. This results in an inaccurate frequency being stored by cpufreq in its policy structure when the CPU is brought online. [1] Consequently, if the userspace governor tries to set the frequency to a new value, there is a possibility that it would be the erroneous value stored earlier. In such a scenario, cpufreq would assume that the requested frequency has already been set and return early, resulting in the correct/new frequency request never making it to the hardware. Since the operating frequency is liable to this sort of inconsistency, mark the CPPC driver with CPUFREQ_NEED_UPDATE_LIMITS so that it is always invoked when a target frequency update is requested. Link: https://lore.kernel.org/linux-pm/20250619000925.415528-3-pmalani@google.com/ [1] Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Prashant Malani <pmalani@google.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250722055611.130574-2-pmalani@google.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0a1416a49e63c320f6e6c1c8d07e1b58c0d4a3f3 ]

AMU counters on certain CPPC-based platforms tend to yield inaccurate
delivered performance measurements on systems that are idle/mostly idle.
This results in an inaccurate frequency being stored by cpufreq in its
policy structure when the CPU is brought online. [1]

Consequently, if the userspace governor tries to set the frequency to a
new value, there is a possibility that it would be the erroneous value
stored earlier. In such a scenario, cpufreq would assume that the
requested frequency has already been set and return early, resulting in
the correct/new frequency request never making it to the hardware.

Since the operating frequency is liable to this sort of inconsistency,
mark the CPPC driver with CPUFREQ_NEED_UPDATE_LIMITS so that it is always
invoked when a target frequency update is requested.

Link: https://lore.kernel.org/linux-pm/20250619000925.415528-3-pmalani@google.com/ [1]
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Prashant Malani <pmalani@google.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250722055611.130574-2-pmalani@google.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cpufreq: cppc: Fix invalid return value in .get() callback 2025-05-02T05:59:00+00:00 Marc Zyngier maz@kernel.org 2025-04-13T10:11:42+00:00 dbe413a8cdc6d49a40f02fe7f060a6d4a1da4a3e [ Upstream commit 2b8e6b58889c672e1ae3601d9b2b070be4dc2fbc ] Returning a negative error code in a function with an unsigned return type is a pretty bad idea. It is probably worse when the justification for the change is "our static analisys tool found it". Fixes: cf7de25878a1 ("cppc_cpufreq: Fix possible null pointer dereference") Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2b8e6b58889c672e1ae3601d9b2b070be4dc2fbc ]

Returning a negative error code in a function with an unsigned
return type is a pretty bad idea. It is probably worse when the
justification for the change is "our static analisys tool found it".

Fixes: cf7de25878a1 ("cppc_cpufreq: Fix possible null pointer dereference")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cpufreq: CPPC: Fix wrong return value in cppc_get_cpu_power() 2024-12-05T13:02:12+00:00 Jinjie Ruan ruanjinjie@huawei.com 2024-11-06T01:01:11+00:00 fc514b27c0890e81f751a119b188f0f6f402a0a1 [ Upstream commit b51eb0874d8170028434fbd259e80b78ed9b8eca ] cppc_get_cpu_power() return 0 if the policy is NULL. Then in em_create_perf_table(), the later zero check for power is not valid as power is uninitialized. As Quentin pointed out, kernel energy model core check the return value of active_power() first, so if the callback failed it should tell the core. So return -EINVAL to fix it. Fixes: a78e72075642 ("cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw()") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Suggested-by: Quentin Perret <qperret@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b51eb0874d8170028434fbd259e80b78ed9b8eca ]

cppc_get_cpu_power() return 0 if the policy is NULL. Then in
em_create_perf_table(), the later zero check for power is not valid
as power is uninitialized. As Quentin pointed out, kernel energy model
core check the return value of active_power() first, so if the callback
failed it should tell the core. So return -EINVAL to fix it.

Fixes: a78e72075642 ("cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw()")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Quentin Perret <qperret@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cpufreq: CPPC: Fix wrong return value in cppc_get_cpu_cost() 2024-12-05T13:02:12+00:00 Jinjie Ruan ruanjinjie@huawei.com 2024-11-06T01:12:38+00:00 32005acffc63dce0449031366c58ba2e9e79c13c [ Upstream commit be392aa80f1e5b0b65ccc2a540b9304fefcfe3d8 ] cppc_get_cpu_cost() return 0 if the policy is NULL. Then in em_compute_costs(), the later zero check for cost is not valid as cost is uninitialized. As Quentin pointed out, kernel energy model core check the return value of get_cost() first, so if the callback failed it should tell the core. Return -EINVAL to fix it. Fixes: 1a1374bb8c59 ("cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost()") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/all/c4765377-7830-44c2-84fa-706b6e304e10@stanley.mountain/ Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Suggested-by: Quentin Perret <qperret@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit be392aa80f1e5b0b65ccc2a540b9304fefcfe3d8 ]

cppc_get_cpu_cost() return 0 if the policy is NULL. Then in
em_compute_costs(), the later zero check for cost is not valid
as cost is uninitialized. As Quentin pointed out, kernel energy model
core check the return value of get_cost() first, so if the callback
failed it should tell the core. Return -EINVAL to fix it.

Fixes: 1a1374bb8c59 ("cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost()")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/c4765377-7830-44c2-84fa-706b6e304e10@stanley.mountain/
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Quentin Perret <qperret@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost() 2024-12-05T13:02:06+00:00 Jinjie Ruan ruanjinjie@huawei.com 2024-10-30T08:24:49+00:00 6be57617a38b3f33266acecdb3c063c1c079aaf7 [ Upstream commit 1a1374bb8c5926674973d849feed500bc61ad535 ] cpufreq_cpu_get_raw() may return NULL if the cpu is not in policy->cpus cpu mask and it will cause null pointer dereference, so check NULL for cppc_get_cpu_cost(). Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1a1374bb8c5926674973d849feed500bc61ad535 ]

cpufreq_cpu_get_raw() may return NULL if the cpu is not in
policy->cpus cpu mask and it will cause null pointer dereference,
so check NULL for cppc_get_cpu_cost().

Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw() 2024-12-05T13:02:06+00:00 Jinjie Ruan ruanjinjie@huawei.com 2024-10-30T01:20:19+00:00 65fe2f7fdafe2698a343661800434b3f2e51041e [ Upstream commit a78e7207564258db6e373e86294a85f9d646d35a ] cpufreq_cpu_get_raw() may return NULL if the cpu is not in policy->cpus cpu mask and it will cause null pointer dereference. Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a78e7207564258db6e373e86294a85f9d646d35a ]

cpufreq_cpu_get_raw() may return NULL if the cpu is not in
policy->cpus cpu mask and it will cause null pointer dereference.

Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cppc_cpufreq: Use desired perf if feedback ctrs are 0 or unchanged 2024-12-05T13:02:01+00:00 Jie Zhan zhanjie9@hisilicon.com 2024-09-29T03:32:13+00:00 12b63e2260f5715bfddffe274c642b9e67178504 [ Upstream commit c47195631960b626058c335aec31f186fa854f97 ] The CPPC performance feedback counters could be 0 or unchanged when the target cpu is in a low-power idle state, e.g. power-gated or clock-gated. When the counters are 0, cppc_cpufreq_get_rate() returns 0 KHz, which makes cpufreq_online() get a false error and fail to generate a cpufreq policy. When the counters are unchanged, the existing cppc_perf_from_fbctrs() returns a cached desired perf, but some platforms may update the real frequency back to the desired perf reg. For the above cases in cppc_cpufreq_get_rate(), get the latest desired perf from the CPPC reg to reflect the frequency because some platforms may update the actual frequency back there; if failed, use the cached desired perf. Fixes: 6a4fec4f6d30 ("cpufreq: cppc: cppc_cpufreq_get_rate() returns zero in all error cases.") Signed-off-by: Jie Zhan <zhanjie9@hisilicon.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> Reviewed-by: Huisong Li <lihuisong@huawei.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c47195631960b626058c335aec31f186fa854f97 ]

The CPPC performance feedback counters could be 0 or unchanged when the
target cpu is in a low-power idle state, e.g. power-gated or clock-gated.

When the counters are 0, cppc_cpufreq_get_rate() returns 0 KHz, which makes
cpufreq_online() get a false error and fail to generate a cpufreq policy.

When the counters are unchanged, the existing cppc_perf_from_fbctrs()
returns a cached desired perf, but some platforms may update the real
frequency back to the desired perf reg.

For the above cases in cppc_cpufreq_get_rate(), get the latest desired perf
from the CPPC reg to reflect the frequency because some platforms may
update the actual frequency back there; if failed, use the cached desired
perf.

Fixes: 6a4fec4f6d30 ("cpufreq: cppc: cppc_cpufreq_get_rate() returns zero in all error cases.")
Signed-off-by: Jie Zhan <zhanjie9@hisilicon.com>
Reviewed-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
move asm/unaligned.h to linux/unaligned.h 2024-10-02T21:23:23+00:00 Al Viro viro@zeniv.linux.org.uk 2024-10-01T19:35:57+00:00 5f60d5f6bbc12e782fac78110b0ee62698f3b576 asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h 
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
cpufreq/cppc: Use NSEC_PER_MSEC for deadline task 2024-09-11T09:25:10+00:00 Christian Loehle christian.loehle@arm.com 2024-08-13T14:43:47+00:00 4eb71e3b4550593d9a862cc0aa754fad98679783 Convert the cppc deadline task attributes to use the available definitions to make them more readable. No functional change. Signed-off-by: Christian Loehle <christian.loehle@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20240813144348.1180344-4-christian.loehle@arm.com 
Convert the cppc deadline task attributes to use the available
definitions to make them more readable.
No functional change.

Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20240813144348.1180344-4-christian.loehle@arm.com