linux.git/kernel/power/energy_model.c, branch v7.1 Linux kernel source tree Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-22T01:09:51+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-02-22T00:37:42+00:00 bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43 This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21T09:02:28+00:00 Kees Cook kees@kernel.org 2026-02-21T07:49:23+00:00 69050f8d6d075dc01af7a5f2f550a8067510366f This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org> 
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
PM: EM: Fix memory leak in em_create_pd() error path 2026-01-08T15:55:21+00:00 Malaya Kumar Rout mrout@redhat.com 2026-01-05T10:37:29+00:00 e25348c5405c38c7b5e7b833898f2d205289186a When ida_alloc() fails in em_create_pd(), the function returns without freeing the previously allocated 'pd' structure, leading to a memory leak. The 'pd' pointer is allocated either at line 436 (for CPU devices with cpumask) or line 442 (for other devices) using kzalloc(). Additionally, the function incorrectly returns -ENOMEM when ida_alloc() fails, ignoring the actual error code returned by ida_alloc(), which can fail for reasons other than memory exhaustion. Fix both issues by: 1. Freeing the 'pd' structure with kfree() when ida_alloc() fails 2. Returning the actual error code from ida_alloc() instead of -ENOMEM This ensures proper cleanup on the error path and accurate error reporting. Fixes: cbe5aeedecc7 ("PM: EM: Assign a unique ID when creating a performance domain") Signed-off-by: Malaya Kumar Rout <mrout@redhat.com> Reviewed-by: Changwoo Min <changwoo@igalia.com> Link: https://patch.msgid.link/20260105103730.65626-1-mrout@redhat.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
When ida_alloc() fails in em_create_pd(), the function returns without
freeing the previously allocated 'pd' structure, leading to a memory leak.
The 'pd' pointer is allocated either at line 436 (for CPU devices with
cpumask) or line 442 (for other devices) using kzalloc().

Additionally, the function incorrectly returns -ENOMEM when ida_alloc()
fails, ignoring the actual error code returned by ida_alloc(), which can
fail for reasons other than memory exhaustion.

Fix both issues by:
 1. Freeing the 'pd' structure with kfree() when ida_alloc() fails
 2. Returning the actual error code from ida_alloc() instead of -ENOMEM

This ensures proper cleanup on the error path and accurate error reporting.

Fixes: cbe5aeedecc7 ("PM: EM: Assign a unique ID when creating a performance domain")
Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
Reviewed-by:  Changwoo Min <changwoo@igalia.com>
Link: https://patch.msgid.link/20260105103730.65626-1-mrout@redhat.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Add to em_pd_list only when no failure 2025-10-29T12:37:00+00:00 Peng Fan peng.fan@nxp.com 2025-10-28T14:23:32+00:00 65df3a9629c10d70593bc90b2ca6b235b7a24909 When em_create_perf_table() returns failure, pd is freed, there dev->em_pd is not valid. Then accessing dev->em_pd->node will trigger kernel panic in em_dev_register_pd_no_update(). So return early if 'ret' is non-zero. Kernel dump: cpu cpu0: EM: invalid power: 0 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Mem abort info: pc : em_dev_register_pd_no_update+0xb4/0x79c lr : em_dev_register_pd_no_update+0x9c/0x79c Call trace: em_dev_register_pd_no_update+0xb4/0x79c (P) em_dev_register_perf_domain+0x18/0x58 scmi_cpufreq_register_em+0x84/0xb8 cpufreq_online+0x48c/0xb74 cpufreq_add_dev+0x80/0x98 subsys_interface_register+0x100/0x11c cpufreq_register_driver+0x158/0x278 scmi_cpufreq_probe+0x1f8/0x2e0 scmi_dev_probe+0x28/0x3c really_probe+0xbc/0x29c __driver_probe_device+0x78/0x12c driver_probe_device+0x3c/0x15c __device_attach_driver+0xb8/0x134 bus_for_each_drv+0x84/0xe4 Fixes: cbe5aeedecc7 ("PM: EM: Assign a unique ID when creating a performance domain") Signed-off-by: Peng Fan <peng.fan@nxp.com> Reviewed-by: Changwoo Min <changwoo@igalia.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://patch.msgid.link/20251028-fix-energy-v1-1-ab854fd6a97c@nxp.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
When em_create_perf_table() returns failure, pd is freed, there dev->em_pd
is not valid. Then accessing dev->em_pd->node will trigger kernel panic
in em_dev_register_pd_no_update(). So return early if 'ret' is non-zero.

Kernel dump:
cpu cpu0: EM: invalid power: 0
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000008
Mem abort info:
pc : em_dev_register_pd_no_update+0xb4/0x79c
lr : em_dev_register_pd_no_update+0x9c/0x79c
Call trace:
 em_dev_register_pd_no_update+0xb4/0x79c (P)
 em_dev_register_perf_domain+0x18/0x58
 scmi_cpufreq_register_em+0x84/0xb8
 cpufreq_online+0x48c/0xb74
 cpufreq_add_dev+0x80/0x98
 subsys_interface_register+0x100/0x11c
 cpufreq_register_driver+0x158/0x278
 scmi_cpufreq_probe+0x1f8/0x2e0
 scmi_dev_probe+0x28/0x3c
 really_probe+0xbc/0x29c
 __driver_probe_device+0x78/0x12c
 driver_probe_device+0x3c/0x15c
 __device_attach_driver+0xb8/0x134
 bus_for_each_drv+0x84/0xe4

Fixes: cbe5aeedecc7 ("PM: EM: Assign a unique ID when creating a performance domain")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20251028-fix-energy-v1-1-ab854fd6a97c@nxp.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Notify an event when the performance domain changes 2025-10-22T19:44:38+00:00 Changwoo Min changwoo@igalia.com 2025-10-20T22:09:14+00:00 a1b17c9ac87a21b677077bc47d7579a2897a13f3 Send an event to userspace when a performance domain is created or deleted, or its energy model is updated. Signed-off-by: Changwoo Min <changwoo@igalia.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://patch.msgid.link/20251020220914.320832-11-changwoo@igalia.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Send an event to userspace when a performance domain is created or deleted,
or its energy model is updated.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20251020220914.320832-11-changwoo@igalia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Add an iterator and accessor for the performance domain 2025-10-22T19:44:37+00:00 Changwoo Min changwoo@igalia.com 2025-10-20T22:09:09+00:00 7928339cfe7d80f35bca905f0a2358271a4e6aa7 Add an iterator function (for_each_em_perf_domain) that iterates all the performance domains in the global list. A passed callback function (cb) is called for each performance domain. Additionally, add a lookup function (em_perf_domain_get_by_id) that searches for a performance domain by matching the ID in the global list. Signed-off-by: Changwoo Min <changwoo@igalia.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://patch.msgid.link/20251020220914.320832-6-changwoo@igalia.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Add an iterator function (for_each_em_perf_domain) that iterates all the
performance domains in the global list. A passed callback function (cb) is
called for each performance domain.

Additionally, add a lookup function (em_perf_domain_get_by_id) that
searches for a performance domain by matching the ID in the global list.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20251020220914.320832-6-changwoo@igalia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Expose the ID of a performance domain via debugfs 2025-10-22T19:44:37+00:00 Changwoo Min changwoo@igalia.com 2025-10-20T22:09:06+00:00 ee50b8bb6b5d62fc2ebff872ee7ecb3a9380ec64 For ease of debugging, let's expose the assigned ID of a performance domain through debugfs (e.g., /sys/kernel/debug/energy_model/cpu0/id). Signed-off-by: Changwoo Min <changwoo@igalia.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://patch.msgid.link/20251020220914.320832-3-changwoo@igalia.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
For ease of debugging, let's expose the assigned ID of a performance
domain through debugfs (e.g., /sys/kernel/debug/energy_model/cpu0/id).

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20251020220914.320832-3-changwoo@igalia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Assign a unique ID when creating a performance domain 2025-10-22T19:44:37+00:00 Changwoo Min changwoo@igalia.com 2025-10-20T22:09:05+00:00 cbe5aeedecc72314c3a8fd0d41d9b270f576aee1 It is necessary to refer to a specific performance domain from a userspace. For example, the energy model of a particular performance domain is updated. To this end, assign a unique ID to each performance domain to address it, and manage them in a global linked list to look up a specific one by matching ID. IDA is used for ID assignment, and the mutex is used to protect the global list from concurrent access. Note that the mutex (em_pd_list_mutex) is not supposed to hold while holding em_pd_mutex to avoid ABBA deadlock. Signed-off-by: Changwoo Min <changwoo@igalia.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://patch.msgid.link/20251020220914.320832-2-changwoo@igalia.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
It is necessary to refer to a specific performance domain from a
userspace. For example, the energy model of a particular performance
domain is updated.

To this end, assign a unique ID to each performance domain to address it,
and manage them in a global linked list to look up a specific one by
matching ID. IDA is used for ID assignment, and the mutex is used to
protect the global list from concurrent access.

Note that the mutex (em_pd_list_mutex) is not supposed to hold while
holding em_pd_mutex to avoid ABBA deadlock.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20251020220914.320832-2-changwoo@igalia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Fix late boot with holes in CPU topology 2025-09-15T10:02:24+00:00 Christian Loehle christian.loehle@arm.com 2025-08-31T21:43:57+00:00 1ebe8f7e782523e62cd1fa8237f7afba5d1dae83 Commit e3f1164fc9ee ("PM: EM: Support late CPUs booting and capacity adjustment") added a mechanism to handle CPUs that come up late by retrying when any of the `cpufreq_cpu_get()` call fails. However, if there are holes in the CPU topology (offline CPUs, e.g. nosmt), the first missing CPU causes the loop to break, preventing subsequent online CPUs from being updated. Instead of aborting on the first missing CPU policy, loop through all and retry if any were missing. Fixes: e3f1164fc9ee ("PM: EM: Support late CPUs booting and capacity adjustment") Suggested-by: Kenneth Crudup <kenneth.crudup@gmail.com> Reported-by: Kenneth Crudup <kenneth.crudup@gmail.com> Link: https://lore.kernel.org/linux-pm/40212796-734c-4140-8a85-854f72b8144d@panix.com/ Cc: 6.9+ <stable@vger.kernel.org> # 6.9+ Signed-off-by: Christian Loehle <christian.loehle@arm.com> Link: https://patch.msgid.link/20250831214357.2020076-1-christian.loehle@arm.com [ rjw: Drop the new pr_debug() message which is not very useful ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Commit e3f1164fc9ee ("PM: EM: Support late CPUs booting and capacity
adjustment") added a mechanism to handle CPUs that come up late by
retrying when any of the `cpufreq_cpu_get()` call fails.

However, if there are holes in the CPU topology (offline CPUs, e.g.
nosmt), the first missing CPU causes the loop to break, preventing
subsequent online CPUs from being updated.

Instead of aborting on the first missing CPU policy, loop through all
and retry if any were missing.

Fixes: e3f1164fc9ee ("PM: EM: Support late CPUs booting and capacity adjustment")
Suggested-by: Kenneth Crudup <kenneth.crudup@gmail.com>
Reported-by: Kenneth Crudup <kenneth.crudup@gmail.com>
Link: https://lore.kernel.org/linux-pm/40212796-734c-4140-8a85-854f72b8144d@panix.com/
Cc: 6.9+ <stable@vger.kernel.org> # 6.9+
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20250831214357.2020076-1-christian.loehle@arm.com
[ rjw: Drop the new pr_debug() message which is not very useful ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Add function for registering a PD without capacity update 2025-09-10T10:03:19+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2025-09-05T13:44:45+00:00 e0423541477dfb684fbc6e6b5386054bc650f264 The intel_pstate driver manages CPU capacity changes itself and it does not need an update of the capacity of all CPUs in the system to be carried out after registering a PD. Moreover, in some configurations (for instance, an SMT-capable hybrid x86 system booted with nosmt in the kernel command line) the em_check_capacity_update() call at the end of em_dev_register_perf_domain() always fails and reschedules itself to run once again in 1 s, so effectively it runs in vain every 1 s forever. To address this, introduce a new variant of em_dev_register_perf_domain(), called em_dev_register_pd_no_update(), that does not invoke em_check_capacity_update(), and make intel_pstate use it instead of the original. Fixes: 7b010f9b9061 ("cpufreq: intel_pstate: EAS support for hybrid platforms") Closes: https://lore.kernel.org/linux-pm/40212796-734c-4140-8a85-854f72b8144d@panix.com/ Reported-by: Kenneth R. Crudup <kenny@panix.com> Tested-by: Kenneth R. Crudup <kenny@panix.com> Cc: 6.16+ <stable@vger.kernel.org> # 6.16+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
The intel_pstate driver manages CPU capacity changes itself and it does
not need an update of the capacity of all CPUs in the system to be
carried out after registering a PD.

Moreover, in some configurations (for instance, an SMT-capable
hybrid x86 system booted with nosmt in the kernel command line) the
em_check_capacity_update() call at the end of em_dev_register_perf_domain()
always fails and reschedules itself to run once again in 1 s, so
effectively it runs in vain every 1 s forever.

To address this, introduce a new variant of em_dev_register_perf_domain(),
called em_dev_register_pd_no_update(), that does not invoke
em_check_capacity_update(), and make intel_pstate use it instead of the
original.

Fixes: 7b010f9b9061 ("cpufreq: intel_pstate: EAS support for hybrid platforms")
Closes: https://lore.kernel.org/linux-pm/40212796-734c-4140-8a85-854f72b8144d@panix.com/
Reported-by: Kenneth R. Crudup <kenny@panix.com>
Tested-by: Kenneth R. Crudup <kenny@panix.com>
Cc: 6.16+ <stable@vger.kernel.org> # 6.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>