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).
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.
+ /* * 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
