Several core ACPI device drivers set acpi_device_class() for the given
struct acpi_device to whatever they like, but that value is never used
unless the driver itself uses it and, sadly, they neglect to clear it on
remove. Since the only one of them still using acpi_device_class()
after previous changes is the button driver, update the others to stop
setting it in vain. Also drop the related device class sybmols that
become redundant.
Since the ACPI button driver continues to use acpi_device_class(), make
it clear the struct field represented by acpi_device_class() in its
remove callback.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/3706295.iIbC2pHGDl@rafael.j.wysocki
ACPI drivers usually set acpi_device_name() for the given struct
acpi_device to whatever they like, but that value is never used unless
the driver itself uses it and, quite unfortunately, drivers neglect to
clear it on remove. Some drivers use it for printing messages or
initializing the names of subordinate devices, but it is better to use
string literals for that, especially if the given one is used just once.
To eliminate unnecessary overhead related to acpi_device_name()
handling, rework multiple core ACPI device drivers to stop setting
acpi_device_name() for struct acpi_device objects manipulated
by them and use a string literal instead of it where applicable.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/10840483.nUPlyArG6x@rafael.j.wysocki
Notice that acpi_processor_power_init() and acpi_processor_power_exit()
don't need to return any values because their callers don't check them
anyway, so redefine those functions as void.
While at it, rearrange the code in acpi_processor_power_init() to
reduce the indentation level, get rid of a redundant local variable
in that function, and rephrase a code comment in it.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20251223100914.2407069-5-lihuisong@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Empty stubs are defined in processor.h for some functions provided by
the ACPI processor idle driver, but those functions are only used in
the main ACPI processor driver which requires the ACPI processor idle
driver to be present (selecting CONFIG_ACPI_PROCESSOR causes
CONFIG_ACPI_PROCESSOR_IDLE to be selected too automatically).
This means that the empty stubs in question are not really necessary and
if both CONFIG_ACPI_PROCESSOR and CONFIG_ACPI_PROCESSOR_IDLE are unset,
the compiler complains that they are defined, but not used. Drop them
to get rid of the compiler warning.
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20251223100914.2407069-3-lihuisong@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently, the ACPI idle driver is registered from within a CPU
hotplug callback. Although this didn't cause any functional issues,
this is questionable and confusing. And it is better to register
the cpuidle driver when all of the CPUs have been brought up.
So add a new function to initialize acpi_idle_driver based on the
power management information of an available CPU and register cpuidle
driver in acpi_processor_driver_init().
This commit has four changes under the commit 7a8c994cbb (ACPI:
processor: idle: Optimize ACPI idle driver registration):
1) move acpi_processor_register_idle_driver() ahead of the
driver_register().
2) add acpi_processor_cstate_first_run_checks() before calling
acpi_processor_get_power_info().
3) squash the commit 9d68320b2b (ACPI: processor: idle: Fix
function defined but not used warning) into this change.
4) use for_each_possible_cpu(cpu) to scan all possible cpus.
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
[ rjw: New comment edits, changelog tweak ]
Link: https://patch.msgid.link/20251223100914.2407069-2-lihuisong@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit 5020d05b34 ("ACPI: processor: Remove unused empty stubs
of some functions") because it depends on a problematic one.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit bdf780fbce ("ACPI: processor: idle: Rearrange declarations
in header file") because it depends on a problematic one.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit fbd401e95e ("ACPI: processor: idle: Redefine two
functions as void") because it depends on a problematic one.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit 559f2eacc8 ACPI: processor: Do not expose global variable
acpi_idle_driver" because it depends on a problematic one.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Notice that acpi_processor_power_init() and acpi_processor_power_exit()
don't need to return any values because their callers don't check them
anyway, so redefine those functions as void.
While at it, rearrange the code in acpi_processor_power_init() to
reduce the indentation level, get rid of a redundant local variable
in that function, and rephrase a code comment in it.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Empty stubs are defined in processor.h for some functions provided by
the ACPI processor idle driver, but those functions are only used in
the main ACPI processor driver which requires the ACPI processor idle
driver to be present (selecting CONFIG_ACPI_PROCESSOR causes
CONFIG_ACPI_PROCESSOR_IDLE to be selected too automatically).
This means that the empty stubs in question are not really necessary and
if both CONFIG_ACPI_PROCESSOR and CONFIG_ACPI_PROCESSOR_IDLE are unset,
the compiler complains that they are defined, but not used. Drop them
to get rid of the compiler warning.
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Link: https://patch.msgid.link/20250911112408.1668431-2-lihuisong@huawei.com
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently, the ACPI idle driver is registered from within a CPU
hotplug callback. Although this didn't cause any functional issues,
this is questionable and confusing. And it is better to register
the cpuidle driver when all of the CPUs have been brought up.
So add a new function to initialize acpi_idle_driver based on the
power management information of an available CPU and register cpuidle
driver in acpi_processor_driver_init().
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Link: https://patch.msgid.link/20250728070612.1260859-3-lihuisong@huawei.com
[ rjw: Added missing inline modifiers ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fix some related issues (done in a single patch to avoid introducing
intermediate bisect warnings):
1) The SMP version of mwait_play_dead() doesn't return, but its
!SMP counterpart does. Make its calling behavior consistent by
resolving the !SMP version to a BUG(). It should never be called
anyway, this just enforces that at runtime and enables its callers
to be marked as __noreturn.
2) While the SMP definition of mwait_play_dead() is annotated as
__noreturn, the declaration isn't. Nor is it listed in
tools/objtool/noreturns.h. Fix that.
3) Similar to #1, the SMP version of acpi_processor_ffh_play_dead()
doesn't return but its !SMP counterpart does. Make the !SMP
version a BUG(). It should never be called.
4) acpi_processor_ffh_play_dead() doesn't return, but is lacking any
__noreturn annotations. Fix that.
This fixes the following objtool warnings:
vmlinux.o: warning: objtool: acpi_processor_ffh_play_dead+0x67: mwait_play_dead() is missing a __noreturn annotation
vmlinux.o: warning: objtool: acpi_idle_play_dead+0x3c: acpi_processor_ffh_play_dead() is missing a __noreturn annotation
Fixes: a7dd183f0b ("x86/smp: Allow calling mwait_play_dead with an arbitrary hint")
Fixes: 541ddf31e3 ("ACPI/processor_idle: Add FFH state handling")
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/e885c6fa9e96a61471b33e48c2162d28b15b14c5.1740962711.git.jpoimboe@kernel.org
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 21fb59ab4b
("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 279f838a61 ("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: 279f838a61 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()")
Reported-by: Ivan Shapovalov <intelfx@intelfx.name>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219431
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20241104222855.3959267-1-superm1@kernel.org
[ rjw: Changelog edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Separate code paths, combined with a flag set in acpi_processor.c to
indicate a struct acpi_processor was for a hotplugged CPU ensured that
per CPU data was only set up the first time that a CPU was initialized.
This appears to be unnecessary as the paths can be combined by letting
the online logic also handle any CPUs online at the time of driver load.
Motivation for this change, beyond simplification, is that ARM64
virtual CPU HP uses the same code paths for hotplug and cold path in
acpi_processor.c so had no easy way to set the flag for hotplug only.
Removing this necessity will enable ARM64 vCPU HP to reuse the existing
code paths.
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Miguel Luis <miguel.luis@oracle.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240529133446.28446-2-Jonathan.Cameron@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Provide common prototypes for arch_register_cpu() and
arch_unregister_cpu(). These are called by acpi_processor.c, with weak
versions, so the prototype for this is already set. It is generally not
necessary for function prototypes to be conditional on preprocessor macros.
Some architectures (e.g. Loongarch) are missing the prototype for this, and
rather than add it to Loongarch's asm/cpu.h, do the job once for everyone.
Since this covers everyone, remove the now unnecessary prototypes in
asm/cpu.h, and therefore remove the 'static' from one of ia64's
arch_register_cpu() definitions.
[ tglx: Bring back the ia64 part and remove the ACPI prototypes ]
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1qkoRr-0088Q8-Da@rmk-PC.armlinux.org.uk
Silence the following warnings when built with W=1:
| CC drivers/acpi/acpi_processor.c
| warning: no previous prototype for 'arch_register_cpu' [-Wmissing-prototypes]
| int __weak arch_register_cpu(int cpu)
| ^
| CC drivers/acpi/acpi_processor.c
| warning: no previous prototype for 'arch_unregister_cpu' [-Wmissing-prototypes]
| void __weak arch_unregister_cpu(int cpu) {}
| ^
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Silence the following warnings when built with W=1:
| CC drivers/acpi/processor_idle.c
| warning: no previous prototype for 'acpi_processor_ffh_lpi_probe' [-Wmissing-prototypes]
| int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
| ^
| CC drivers/acpi/processor_idle.c
| warning: no previous prototype for 'acpi_processor_ffh_lpi_enter' [-Wmissing-prototypes]
| int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
| ^
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
