Commit b79276dc authored by Mario Limonciello's avatar Mario Limonciello Committed by Rafael J. Wysocki
Browse files

ACPI: processor: Move arch_init_invariance_cppc() call later 



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 21fb59ab
("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 279f838a ("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: 279f838a ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()")
Reported-by: default avatarIvan Shapovalov <intelfx@intelfx.name>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219431


Tested-by: default avatarOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20241104222855.3959267-1-superm1@kernel.org


[ rjw: Changelog edit ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 59b723cd

arch/arm64/include/asm/topology.h

+0 −4
Original line number Diff line number Diff line
@@ -26,10 +26,6 @@ void update_freq_counters_refs(void); 
#define arch_scale_freq_invariant topology_scale_freq_invariant

#define arch_scale_freq_ref topology_get_freq_ref



#ifdef CONFIG_ACPI_CPPC_LIB

#define arch_init_invariance_cppc topology_init_cpu_capacity_cppc

#endif



/* Replace task scheduler's default cpu-invariant accounting */

#define arch_scale_cpu_capacity topology_get_cpu_scale

arch/x86/include/asm/topology.h

+0 −5
Original line number Diff line number Diff line
@@ -305,9 +305,4 @@ static inline void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled 
extern void arch_scale_freq_tick(void);

#define arch_scale_freq_tick arch_scale_freq_tick



#ifdef CONFIG_ACPI_CPPC_LIB

void init_freq_invariance_cppc(void);

#define arch_init_invariance_cppc init_freq_invariance_cppc

#endif



#endif /* _ASM_X86_TOPOLOGY_H */

arch/x86/kernel/acpi/cppc.c

+6 −1
Original line number Diff line number Diff line
@@ -110,7 +110,7 @@ static void amd_set_max_freq_ratio(void) 


static DEFINE_MUTEX(freq_invariance_lock);



void init_freq_invariance_cppc(void)

static inline void init_freq_invariance_cppc(void)

{

	static bool init_done;
@@ -127,6 +127,11 @@ void init_freq_invariance_cppc(void) 
	mutex_unlock(&freq_invariance_lock);

}



void acpi_processor_init_invariance_cppc(void)

{

	init_freq_invariance_cppc();

}



/*

 * Get the highest performance register value.

 * @cpu: CPU from which to get highest performance.

drivers/acpi/cppc_acpi.c

+0 −6
Original line number Diff line number Diff line
@@ -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;

drivers/acpi/processor_driver.c

+9 −0
Original line number Diff line number Diff line
@@ -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)

{ }



/*

 * 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);