Dan reported a possible NULL pointer dereference in amd-pstate-ut.c from
static analysis and sure enough, running amd-pstate-ut in active mode
with amd_dynamic_epp=enable results in a crash as a reult of the policy
reference being set to NULL early, before disabling dynamic EPP.
Kalpana also reported seeing amd-pstate-ut error out with -EBUSY for
"amd_pstate_ut_epp" test when starting from the passive mode and
amd_dynamic_epp=enable in the command line. The reason for the failure
is that the command line enables dynamic_epp by default after the mode
switch and the modifications to EPP values are blocked when running in
dynamic EPP mode.
Solution to both problems is to toggle off dynamic_epp *after* the mode
switch when the driver grabs the policy reference again since the unit
test is in full control of the policy after that point.
The final restoration step will reset the dynamic_epp state via mode
switch based on the initial conditions of the system.
Reported-by: Kalpana Shetty <kalpana.shetty@amd.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/linux-pm/ahEq0CvdBX0T7_cO@stanley.mountain/
Fixes: f9f16835d4 ("cpufreq/amd-pstate-ut: Drop policy reference before driver switch")
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://patch.msgid.link/20260523055503.7651-1-kprateek.nayak@amd.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge amd-pstate fixes for 7.1 (05/14/2026) from Mario Limonciello:
"A number of fixes to the dynamic epp feature which was new
to kernel 7.1, including making it opt in only."
* tag 'amd-pstate-v7.1-2026-05-14' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux:
cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP
cpufreq/amd-pstate-ut: Drop policy reference before driver switch
cpufreq/amd-pstate: Use "epp_default_dc" as default when dynamic_epp is disabled
cpufreq/amd-pstate: Reorder notifier unregistration and floor perf reset
cpufreq/amd-pstate: Allow writes to dynamic_epp when state isn't modified
cpufreq/amd-pstate: Return -ENOMEM on failure to allocate profile_name
cpufreq/amd-pstate: Grab "amd_pstate_driver_lock" when toggling dynamic_epp
Bartlett Lake P-core only SKUs (e.g. Intel Core 9 273PE)
do not report X86_FEATURE_HYBRID_CPU and are not in
intel_hybrid_scaling_factor[]. In hwp_get_cpu_scaling(), the
non-hybrid fallback then applies core_get_scaling() (100000),
producing cpuinfo_max_freq values that exceed the documented Max
Turbo Frequency:
intel_pstate: CPU0: PERF_CTL turbo = 57
intel_pstate: CPU0: HWP_CAP guaranteed = 30
intel_pstate: CPU0: HWP_CAP highest = 70
intel_pstate: CPU0: HWP-to-frequency scaling factor: 100000
intel_pstate: set_policy cpuinfo.max 7000000 policy->max 7000000
...
intel_pstate: CPU12: PERF_CTL turbo = 57
intel_pstate: CPU12: HWP_CAP guaranteed = 30
intel_pstate: CPU12: HWP_CAP highest = 73
intel_pstate: CPU12: HWP-to-frequency scaling factor: 100000
intel_pstate: set_policy cpuinfo.max 7300000 policy->max 7300000
...
Per the Intel datasheet [1], the Intel Core 9 273PE specifies:
Performance-cores: 12
Efficient-cores: 0
Max Turbo Frequency: 5.7 GHz
Intel Thermal Velocity Boost Frequency: 5.7 GHz
Intel Turbo Boost Max Technology 3.0 Frequency: 5.6 GHz
Performance-core Max Turbo Frequency: 5.4 GHz
Performance-core Base Frequency: 2.3 GHz
Bartlett Lake P-cores are Raptor Cove cores, per
commit d466304c43 ("x86/cpu: Add CPU model number for Bartlett
Lake CPUs with Raptor Cove cores"). The Alder Lake and Raptor Lake
P-core entries in intel_hybrid_scaling_factor[] use
HYBRID_SCALING_FACTOR_ADL (78741). The same factor applies to
Bartlett Lake.
Add Bartlett Lake to intel_hybrid_scaling_factor[] with
HYBRID_SCALING_FACTOR_ADL so HWP performance levels map to the
correct CPU frequencies matching the datasheet's Max Turbo Frequency.
Link: https://www.intel.com/content/www/us/en/products/sku/245717/intel-core-9-processor-273pe-36m-cache-up-to-5-70-ghz/specifications.html [1]
Signed-off-by: Henry Tseng <henrytseng@qnap.com>
[ rjw: Changelog tweak ]
Link: https://patch.msgid.link/20260513102847.75179-1-henrytseng@qnap.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Recent changes to the EPP unit test tries to perform a driver switch
with a cpufreq_policy reference held when the driver is loaded into
anything but the active mode which leads to a circular dependency and
the unit test hanging indefinitely.
Drop the reference before driver switch and grab it back once the driver
mode is stabilized for the test.
The EPP writes are only possible with CPUFREQ_POLICY_POWERSAVE policy.
Temporarily switch the cpudata->policy (while holding the write end of
the policy->rwsem) to CPUFREQ_POLICY_POWERSAVE and restore the original
policy once tests are done. To ensure the final EPP is correct in case
the driver started with CPUFREQ_POLICY_PERFORMANCE, EPP performance is
tested last.
The __free() based cleanup for cpufreq_policy is lost in the process.
Reported-by: Kalpana Shetty <kalpana.shetty@amd.com>
Fixes: 7e173bc310 ("cpufreq/amd-pstate-ut: Add a unit test for raw EPP")
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20260508051748.10484-7-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
If "dynamic_epp" is disabled, the driver initialization and the default
EPP selection from sysfs currently sets the EPP based on the power
supply state of the system at that time but there is no power supply
callbacks registered to toggle it when the power supply state changes.
This can lead to faster battery drain on platforms that start off while
being plugged to the wall but later move to battery power since the EPP
stays at AMD_CPPC_EPP_PERFORMANCE.
Use "epp_default_dc" as the default EPP selection when dynamic_epp is
disabled, restoring older behavior. On servers, this defaults to
AMD_CPPC_EPP_PERFORMANCE and on other platforms, it defaults to
AMD_CPPC_EPP_BALANCE_PERFORMANCE.
Fixes: e30ca6dd53 ("cpufreq/amd-pstate: Add dynamic energy performance preference")
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20260508051748.10484-6-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Concurrently changing driver mode and dynamic_epp with:
echo passive > /sys/devices/system/cpu/amd_pstate/status&
echo disable > /sys/devices/system/cpu/amd_pstate/dynamic_epp&
hits the WARN_ON_ONCE() in static_key_disable_cpuslocked() and hangs the
system since both sysfs writes are trying to do
amd_pstate_change_driver_mode() without any synchronization.
Grab the "amd_pstate_driver_lock" mutex when modifying "dynamic_epp" to
prevent the two paths from racing with each other. Add a lockdep
assertion for "amd_pstate_driver_lock" in
amd_pstate_change_driver_mode() to formalize the dependency.
Since "cppc_mode" is stable under "amd_pstate_driver_lock", only reload
the driver when in "AMD_PSTATE_ACTIVE" mode and reject all writes when
in passive or guided mode, or if the driver is not loaded, since only
active mode operates on EPP.
Fixes: e30ca6dd53 ("cpufreq/amd-pstate: Add dynamic energy performance preference")
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20260508051748.10484-2-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Pull tracing updates from Steven Rostedt:
- Fix printf format warning for bprintf
sunrpc uses a trace_printk() that triggers a printf warning during
the compile. Move the __printf() attribute around for when debugging
is not enabled the warning will go away
- Remove redundant check for EVENT_FILE_FL_FREED in
event_filter_write()
The FREED flag is checked in the call to event_file_file() and then
checked again right afterward, which is unneeded
- Clean up event_file_file() and event_file_data() helpers
These helper functions played a different role in the past, but now
with eventfs, the READ_ONCE() isn't needed. Simplify the code a bit
and also add a warning to event_file_data() if the file or its data
is not present
- Remove updating file->private_data in tracing open
All access to the file private data is handled by the helper
functions, which do not use file->private_data. Stop updating it on
open
- Show ENUM names in function arguments via BTF in function tracing
When showing the function arguments when func-args option is set for
function tracing, if one of the arguments is found to be an enum,
show the name of the enum instead of its number
- Add new trace_call__##name() API for tracepoints
Tracepoints are enabled via static_branch() blocks, where when not
enabled, there's only a nop that is in the code where the execution
will just skip over it. When tracing is enabled, the nop is converted
to a direct jump to the tracepoint code. Sometimes more calculations
are required to be performed to update the parameters of the
tracepoint. In this case, trace_##name##_enabled() is called which is
a static_branch() that gets enabled only when the tracepoint is
enabled. This allows the extra calculations to also be skipped by the
nop:
if (trace_foo_enabled()) {
x = bar();
trace_foo(x);
}
Where the x=bar() is only performed when foo is enabled. The problem
with this approach is that there's now two static_branch() calls. One
for checking if the tracepoint is enabled, and then again to know if
the tracepoint should be called. The second one is redundant
Introduce trace_call__foo() that will call the foo() tracepoint
directly without doing a static_branch():
if (trace_foo_enabled()) {
x = bar();
trace_call__foo();
}
- Update various locations to use the new trace_call__##name() API
- Move snapshot code out of trace.c
Cleaning up trace.c to not be a "dump all", move the snapshot code
out of it and into a new trace_snapshot.c file
- Clean up some "%*.s" to "%*s"
- Allow boot kernel command line options to be called multiple times
Have options like:
ftrace_filter=foo ftrace_filter=bar ftrace_filter=zoo
Equal to:
ftrace_filter=foo,bar,zoo
- Fix ipi_raise event CPU field to be a CPU field
The ipi_raise target_cpus field is defined as a __bitmask(). There is
now a __cpumask() field definition. Update the field to use that
- Have hist_field_name() use a snprintf() and not a series of strcat()
It's safer to use snprintf() that a series of strcat()
- Fix tracepoint regfunc balancing
A tracepoint can define a "reg" and "unreg" function that gets called
before the tracepoint is enabled, and after it is disabled
respectively. But on error, after the "reg" func is called and the
tracepoint is not enabled, the "unreg" function is not called to tear
down what the "reg" function performed
- Fix output that shows what histograms are enabled
Event variables are displayed incorrectly in the histogram output
Instead of "sched.sched_wakeup.$var", it is showing
"$sched.sched_wakeup.var" where the '$' is in the incorrect location
- Some other simple cleanups
* tag 'trace-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (24 commits)
selftests/ftrace: Add test case for fully-qualified variable references
tracing: Fix fully-qualified variable reference printing in histograms
tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func()
tracing: Rebuild full_name on each hist_field_name() call
tracing: Report ipi_raise target CPUs as cpumask
tracing: Remove duplicate latency_fsnotify() stub
tracing: Preserve repeated trace_trigger boot parameters
tracing: Append repeated boot-time tracing parameters
tracing: Remove spurious default precision from show_event_trigger/filter formats
cpufreq: Use trace_call__##name() at guarded tracepoint call sites
tracing: Remove tracing_alloc_snapshot() when snapshot isn't defined
tracing: Move snapshot code out of trace.c and into trace_snapshot.c
mm: damon: Use trace_call__##name() at guarded tracepoint call sites
btrfs: Use trace_call__##name() at guarded tracepoint call sites
spi: Use trace_call__##name() at guarded tracepoint call sites
i2c: Use trace_call__##name() at guarded tracepoint call sites
kernel: Use trace_call__##name() at guarded tracepoint call sites
tracepoint: Add trace_call__##name() API
tracing: trace_mmap.h: fix a kernel-doc warning
tracing: Pretty-print enum parameters in function arguments
...
Pull power management updates from Rafael Wysocki:
"Once again, cpufreq is the most active development area, mostly
because of the new feature additions and documentation updates in the
amd-pstate driver, but there are also changes in the cpufreq core
related to boost support and other assorted updates elsewhere.
Next up are power capping changes due to the major cleanup of the
Intel RAPL driver.
On the cpuidle front, a new C-states table for Intel Panther Lake is
added to the intel_idle driver, the stopped tick handling in the menu
and teo governors is updated, and there are a couple of cleanups.
Apart from the above, support for Tegra114 is added to devfreq and
there are assorted cleanups of that code, there are also two updates
of the operating performance points (OPP) library, two minor updates
related to hibernation, and cpupower utility man pages updates and
cleanups.
Specifics:
- Update qcom-hw DT bindings to include Eliza hardware (Abel Vesa)
- Update cpufreq-dt-platdev blocklist (Faruque Ansari)
- Minor updates to driver and dt-bindings for Tegra (Thierry Reding,
Rosen Penev)
- Add MAINTAINERS entry for CPPC driver (Viresh Kumar)
- Add support for new features: CPPC performance priority, Dynamic
EPP, Raw EPP, and new unit tests for them to amd-pstate (Gautham
Shenoy, Mario Limonciello)
- Fix sysfs files being present when HW missing and broken/outdated
documentation in the amd-pstate driver (Ninad Naik, Gautham Shenoy)
- Pass the policy to cpufreq_driver->adjust_perf() to avoid using
cpufreq_cpu_get() in the .adjust_perf() callback in amd-pstate
which leads to a scheduling-while-atomic bug (K Prateek Nayak)
- Clean up dead code in Kconfig for cpufreq (Julian Braha)
- Remove max_freq_req update for pre-existing cpufreq policy and add
a boost_freq_req QoS request to save the boost constraint instead
of overwriting the last scaling_max_freq constraint (Pierre
Gondois)
- Embed cpufreq QoS freq_req objects in cpufreq policy so they all
are allocated in one go along with the policy to simplify lifetime
rules and avoid error handling issues (Viresh Kumar)
- Use DMI max speed when CPPC is unavailable in the acpi-cpufreq
scaling driver (Henry Tseng)
- Switch policy_is_shared() in cpufreq to using cpumask_nth() instead
of cpumask_weight() because the former is more efficient (Yury
Norov)
- Use sysfs_emit() in sysfs show functions for cpufreq governor
attributes (Thorsten Blum)
- Update intel_pstate to stop returning an error when "off" is
written to its status sysfs attribute while the driver is already
off (Fabio De Francesco)
- Include current frequency in the debug message printed by
__cpufreq_driver_target() (Pengjie Zhang)
- Refine stopped tick handling in the menu cpuidle governor and
rearrange stopped tick handling in the teo cpuidle governor (Rafael
Wysocki)
- Add Panther Lake C-states table to the intel_idle driver (Artem
Bityutskiy)
- Clean up dead dependencies on CPU_IDLE in Kconfig (Julian Braha)
- Simplify cpuidle_register_device() with guard() (Huisong Li)
- Use performance level if available to distinguish between rates in
OPP debugfs (Manivannan Sadhasivam)
- Fix scoped_guard in dev_pm_opp_xlate_required_opp() (Viresh Kumar)
- Return -ENODATA if the snapshot image is not loaded (Alberto
Garcia)
- Remove inclusion of crypto/hash.h from hibernate_64.c on x86 (Eric
Biggers)
- Clean up and rearrange the intel_rapl power capping driver to make
the respective interface drivers (TPMI, MSR, and MMOI) hold their
own settings and primitives and consolidate PL4 and PMU support
flags into rapl_defaults (Kuppuswamy Sathyanarayanan)
- Correct kernel-doc function parameter names in the power capping
core code (Randy Dunlap)
- Remove unneeded casting for HZ_PER_KHZ in devfreq (Andy Shevchenko)
- Use _visible attribute to replace create/remove_sysfs_files() in
devfreq (Pengjie Zhang)
- Add Tegra114 support to activity monitor device in tegra30-devfreq
as a preparation to upcoming EMC controller support (Svyatoslav
Ryhel)
- Fix mistakes in cpupower man pages, add the boost and epp options
to the cpupower-frequency-info man page, and add the perf-bias
option to the cpupower-info man page (Roberto Ricci)
- Remove unnecessary extern declarations from getopt.h in arguments
parsing functions in cpufreq-set, cpuidle-info, cpuidle-set,
cpupower-info, and cpupower-set utilities (Kaushlendra Kumar)"
* tag 'pm-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
cpufreq/amd-pstate: Add POWER_SUPPLY select for dynamic EPP
cpupower: remove extern declarations in cmd functions
cpuidle: Simplify cpuidle_register_device() with guard()
PM / devfreq: tegra30-devfreq: add support for Tegra114
PM / devfreq: use _visible attribute to replace create/remove_sysfs_files()
PM / devfreq: Remove unneeded casting for HZ_PER_KHZ
MAINTAINERS: amd-pstate: Step down as maintainer, add Prateek as reviewer
cpufreq: Pass the policy to cpufreq_driver->adjust_perf()
cpufreq/amd-pstate: Pass the policy to amd_pstate_update()
cpufreq/amd-pstate-ut: Add a unit test for raw EPP
cpufreq/amd-pstate: Add support for raw EPP writes
cpufreq/amd-pstate: Add support for platform profile class
cpufreq/amd-pstate: add kernel command line to override dynamic epp
cpufreq/amd-pstate: Add dynamic energy performance preference
Documentation: amd-pstate: fix dead links in the reference section
cpufreq/amd-pstate: Cache the max frequency in cpudata
Documentation/amd-pstate: Add documentation for amd_pstate_floor_{freq,count}
Documentation/amd-pstate: List amd_pstate_prefcore_ranking sysfs file
Documentation/amd-pstate: List amd_pstate_hw_prefcore sysfs file
amd-pstate-ut: Add a testcase to validate the visibility of driver attributes
...
Merge ACPI processor driver updates and ACPI CPPC library updates for
7.1-rc1:
- Address multiple assorted issues and clean up the code in the ACPI
processor idle driver (Huisong Li)
- Replace strlcat() in the ACPI processor idle drive with a better
alternative (Andy Shevchenko)
- Rearrange and clean up acpi_processor_errata_piix4() (Rafael Wysocki)
- Move reference performance to capabilities and fix an uninitialized
variable in the ACPI CPPC library (Pengjie Zhang)
- Add support for the Performance Limited Register to the ACPI CPPC
library (Sumit Gupta)
- Add cppc_get_perf() API to read performance controls, extend
cppc_set_epp_perf() for FFH/SystemMemory, and make the ACPI CPPC
library warn on missing mandatory DESIRED_PERF register (Sumit Gupta)
- Modify the cpufreq CPPC driver to update MIN_PERF/MAX_PERF in target
callbacks to allow it to control performance bounds via standard
scaling_min_freq and scaling_max_freq sysfs attributes and add sysfs
documentation for the Performance Limited Register to it (Sumit Gupta)
* acpi-processor:
ACPI: processor: idle: Reset cpuidle on C-state list changes
cpuidle: Extract and export no-lock variants of cpuidle_unregister_device()
ACPI: processor: idle: Fix NULL pointer dereference in hotplug path
ACPI: processor: idle: Reset power_setup_done flag on initialization failure
ACPI: processor: Rearrange and clean up acpi_processor_errata_piix4()
ACPI: processor: idle: Replace strlcat() with better alternative
ACPI: processor: idle: Remove redundant static variable and rename cstate check function
ACPI: processor: idle: Move max_cstate update out of the loop
ACPI: processor: idle: Remove redundant cstate check in acpi_processor_power_init
ACPI: processor: idle: Add missing bounds check in flatten_lpi_states()
* acpi-cppc:
ACPI: CPPC: Check cpc_read() return values consistently
ACPI: CPPC: Fix uninitialized ref variable in cppc_get_perf_caps()
ACPI: CPPC: Move reference performance to capabilities
cpufreq: CPPC: Add sysfs documentation for perf_limited
ACPI: CPPC: add APIs and sysfs interface for perf_limited
cpufreq: cppc: Update MIN_PERF/MAX_PERF in target callbacks
cpufreq: CPPC: Update cached perf_ctrls on sysfs write
ACPI: CPPC: Extend cppc_set_epp_perf() for FFH/SystemMemory
ACPI: CPPC: Warn on missing mandatory DESIRED_PERF register
ACPI: CPPC: Add cppc_get_perf() API to read performance controls
Pull CPUFreq Arm updates for 7.1 from Viresh Kumar:
"- Update qcom-hw DT bindings to include Eliza hardware (Abel Vesa).
- Update cpufreq-dt-platdev blocklist (Faruque Ansari).
- Minor updates to driver and dt-bindings for Tegra (Thierry Reding and
Rosen Penev).
- Add MAINTAINERS entry for CPPC driver (Viresh Kumar)."
* tag 'cpufreq-arm-updates-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
cpufreq: tegra194: remove COMPILE_TEST
cpufreq: Add QCS8300 to cpufreq-dt-platdev blocklist
cpufreq: Add MAINTAINERS entry for CPPC driver
cpufreq: tegra194: Rename Tegra239 to Tegra238
dt-bindings: arm: nvidia: Document the Tegra238 CCPLEX cluster
dt-bindings: cpufreq: qcom-hw: document Eliza cpufreq hardware
Pull amd-pstate new content for 7.1 (2026-04-02) from Mario Limonciello:
"Add support for new features:
* CPPC performance priority
* Dynamic EPP
* Raw EPP
* New unit tests for new features
Fixes for:
* PREEMPT_RT
* sysfs files being present when HW missing
* Broken/outdated documentation"
* tag 'amd-pstate-v7.1-2026-04-02' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux: (22 commits)
MAINTAINERS: amd-pstate: Step down as maintainer, add Prateek as reviewer
cpufreq: Pass the policy to cpufreq_driver->adjust_perf()
cpufreq/amd-pstate: Pass the policy to amd_pstate_update()
cpufreq/amd-pstate-ut: Add a unit test for raw EPP
cpufreq/amd-pstate: Add support for raw EPP writes
cpufreq/amd-pstate: Add support for platform profile class
cpufreq/amd-pstate: add kernel command line to override dynamic epp
cpufreq/amd-pstate: Add dynamic energy performance preference
Documentation: amd-pstate: fix dead links in the reference section
cpufreq/amd-pstate: Cache the max frequency in cpudata
Documentation/amd-pstate: Add documentation for amd_pstate_floor_{freq,count}
Documentation/amd-pstate: List amd_pstate_prefcore_ranking sysfs file
Documentation/amd-pstate: List amd_pstate_hw_prefcore sysfs file
amd-pstate-ut: Add a testcase to validate the visibility of driver attributes
amd-pstate-ut: Add module parameter to select testcases
amd-pstate: Introduce a tracepoint trace_amd_pstate_cppc_req2()
amd-pstate: Add sysfs support for floor_freq and floor_count
amd-pstate: Add support for CPPC_REQ2 and FLOOR_PERF
x86/cpufeatures: Add AMD CPPC Performance Priority feature.
amd-pstate: Make certain freq_attrs conditionally visible
...
cpufreq_cpu_get() can sleep on PREEMPT_RT in presence of concurrent
writer(s), however amd-pstate depends on fetching the cpudata via the
policy's driver data which necessitates grabbing the reference.
Since schedutil governor can call "cpufreq_driver->update_perf()"
during sched_tick/enqueue/dequeue with rq_lock held and IRQs disabled,
fetching the policy object using the cpufreq_cpu_get() helper in the
scheduler fast-path leads to "BUG: scheduling while atomic" on
PREEMPT_RT [1].
Pass the cached cpufreq policy object in sg_policy to the update_perf()
instead of just the CPU. The CPU can be inferred using "policy->cpu".
The lifetime of cpufreq_policy object outlasts that of the governor and
the cpufreq driver (allocated when the CPU is onlined and only reclaimed
when the CPU is offlined / the CPU device is removed) which makes it
safe to be referenced throughout the governor's lifetime.
Closes:https://lore.kernel.org/all/20250731092316.3191-1-spasswolf@web.de/ [1]
Fixes: 1d215f0319 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")
Reported-by: Bert Karwatzki <spasswolf@web.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Gary Guo <gary@garyguo.net> # Rust
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260316081849.19368-3-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
All callers of amd_pstate_update() already have a reference to the
cpufreq_policy object.
Pass the entire policy object and grab the cpudata using
"policy->driver_data" instead of passing the cpudata and unnecessarily
grabbing another read-side reference to the cpufreq policy object when
it is already available in the caller.
No functional changes intended.
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20260316081849.19368-2-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Ensure that all supported raw EPP values work properly.
Export the driver helpers used by the test module so the test can drive
raw EPP writes and temporarily disable dynamic EPP while it runs.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
The energy performance preference field of the CPPC request MSR
supports values from 0 to 255, but the strings only offer 4 values.
The other values are useful for tuning the performance of some
workloads.
Add support for writing the raw energy performance preference value
to the sysfs file. If the last value written was an integer then
an integer will be returned. If the last value written was a string
then a string will be returned.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
The platform profile core allows multiple drivers and devices to
register platform profile support.
When the legacy platform profile interface is used all drivers will
adjust the platform profile as well.
Add support for registering every CPU with the platform profile handler
when dynamic EPP is enabled.
The end result will be that changing the platform profile will modify
EPP accordingly.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Add `amd_dynamic_epp=enable` and `amd_dynamic_epp=disable` to override
the kernel configuration option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`
locally.
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
