On 2024-11-04 at 15:14 -0600, Mario Limonciello wrote: > On 11/4/2024 15:10, Rafael J. Wysocki wrote: > > On Mon, Nov 4, 2024 at 9:54 PM Mario Limonciello <superm1@xxxxxxxxxx> wrote: > > > > > > From: Mario Limonciello <mario.limonciello@xxxxxxx> > > > > > > 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 21fb59ab4b97 > > > ("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 279f838a61f9 ("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. > > > > > > Fixes: 279f838a61f9 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()") > > > Reported-by: Ivan Shapovalov <intelfx@xxxxxxxxxxxx> > > > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219431 > > > Tested-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx> > > > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> > > > --- > > > v3: > > > * Weak symbol instead of macro to help riscv build failure > > > * Update commit message > > > * Add comment > > > --- > > > arch/arm64/include/asm/topology.h | 2 +- > > > arch/x86/include/asm/topology.h | 2 +- > > > drivers/acpi/cppc_acpi.c | 6 ------ > > > drivers/acpi/processor_driver.c | 9 +++++++++ > > > include/acpi/processor.h | 2 ++ > > > 5 files changed, 13 insertions(+), 8 deletions(-) > > > > > > diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h > > > index 5fc3af9f8f29b..8a1860877967e 100644 > > > --- a/arch/arm64/include/asm/topology.h > > > +++ b/arch/arm64/include/asm/topology.h > > > @@ -27,7 +27,7 @@ void update_freq_counters_refs(void); > > > #define arch_scale_freq_ref topology_get_freq_ref > > > > > > #ifdef CONFIG_ACPI_CPPC_LIB > > > -#define arch_init_invariance_cppc topology_init_cpu_capacity_cppc > > > +#define acpi_processor_init_invariance_cppc topology_init_cpu_capacity_cppc > > > #endif > > > > > > /* Replace task scheduler's default cpu-invariant accounting */ > > > diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h > > > index aef70336d6247..0fb705524aeaa 100644 > > > --- a/arch/x86/include/asm/topology.h > > > +++ b/arch/x86/include/asm/topology.h > > > @@ -307,7 +307,7 @@ extern void arch_scale_freq_tick(void); > > > > > > #ifdef CONFIG_ACPI_CPPC_LIB > > > void init_freq_invariance_cppc(void); > > > -#define arch_init_invariance_cppc init_freq_invariance_cppc > > > +#define acpi_processor_init_invariance_cppc init_freq_invariance_cppc > > > #endif > > > > > > #endif /* _ASM_X86_TOPOLOGY_H */ > > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > > > index 1a40f0514eaa3..5c0cc7aae8726 100644 > > > --- a/drivers/acpi/cppc_acpi.c > > > +++ b/drivers/acpi/cppc_acpi.c > > > @@ -671,10 +671,6 @@ static int pcc_data_alloc(int pcc_ss_id) > > > * ) > > > */ > > > > > > -#ifndef arch_init_invariance_cppc > > > -static inline void arch_init_invariance_cppc(void) { } > > > -#endif > > > - > > > /** > > > * acpi_cppc_processor_probe - Search for per CPU _CPC objects. > > > * @pr: Ptr to acpi_processor containing this CPU's logical ID. > > > @@ -905,8 +901,6 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) > > > goto out_free; > > > } > > > > > > - arch_init_invariance_cppc(); > > > - > > > kfree(output.pointer); > > > return 0; > > > > > > diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c > > > index cb52dd000b958..3b281bc1e73c3 100644 > > > --- a/drivers/acpi/processor_driver.c > > > +++ b/drivers/acpi/processor_driver.c > > > @@ -237,6 +237,9 @@ static struct notifier_block acpi_processor_notifier_block = { > > > .notifier_call = acpi_processor_notifier, > > > }; > > > > > > +void __weak acpi_processor_init_invariance_cppc(void) > > > +{ } > > > > Does this actually work if acpi_processor_init_invariance_cppc is a > > macro? How does the compiler know that it needs to use > > init_freq_invariance_cppc() instead of this? > > > > It would work if a __weak definition of init_freq_invariance_cppc() was present. > > I also wasn't sure, so I explicitly added some tracing in > init_freq_invariance_cppc() to make sure it got called and checked it > (GCC 13.2.0). Aren't C macros substituted strictly lexically, i.e. if the #define is present by the time the function definition is parsed, it's just void __weak acpi_processor_init_invariance_cppc(void) {} -> void __weak init_freq_invariance_cppc(void) {} ? So it _is_ a weak definition of init_freq_invariance_cppc(). > > But I'll admit it's a confusing behavior. If you think it's too > confusing I'll swap it around to just axe the macros. ...That said, it does look kinda confusing. Seems to be norm for that arch/ header file though. Anyway, Tested-by: Ivan Shapovalov <intelfx@xxxxxxxxxxxx> > > > > > > + > > > /* > > > * We keep the driver loaded even when ACPI is not running. > > > * This is needed for the powernow-k8 driver, that works even without > > > @@ -270,6 +273,12 @@ static int __init acpi_processor_driver_init(void) > > > NULL, acpi_soft_cpu_dead); > > > > > > acpi_processor_throttling_init(); > > > + > > > + /* > > > + * Frequency invariance calculations on AMD platforms can't be run until > > > + * after acpi_cppc_processor_probe() has been called for all online CPUs. > > > + */ > > > + acpi_processor_init_invariance_cppc(); > > > return 0; > > > err: > > > driver_unregister(&acpi_processor_driver); > > > diff --git a/include/acpi/processor.h b/include/acpi/processor.h > > > index e6f6074eadbf3..a17e97e634a68 100644 > > > --- a/include/acpi/processor.h > > > +++ b/include/acpi/processor.h > > > @@ -465,4 +465,6 @@ extern int acpi_processor_ffh_lpi_probe(unsigned int cpu); > > > extern int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi); > > > #endif > > > > > > +void acpi_processor_init_invariance_cppc(void); > > > + > > > #endif > > > > > > base-commit: 6db936d4ac0fe281af48b4d1ebf69b1523bbac31 > > > -- > > > 2.43.0 > > > >
Attachment:
signature.asc
Description: This is a digitally signed message part