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Commit f594065f authored by Matthew Garrett's avatar Matthew Garrett Committed by Rafael J. Wysocki
Browse files

ACPI: Add fixups for AMD P-state figures 



Some AMD systems may round the frequencies in ACPI tables to 100MHz
boundaries. We can obtain the real frequencies from MSRs, so add a quirk
to fix these frequencies up on AMD systems.

Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
Signed-off-by: default avatarAndre Przywara <andre.przywara@amd.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent a2060958

arch/x86/include/asm/msr-index.h

+1 −0
Original line number Diff line number Diff line
@@ -248,6 +248,7 @@ 


#define MSR_IA32_PERF_STATUS		0x00000198

#define MSR_IA32_PERF_CTL		0x00000199

#define MSR_AMD_PSTATE_DEF_BASE		0xc0010064

#define MSR_AMD_PERF_STATUS		0xc0010063

#define MSR_AMD_PERF_CTL		0xc0010062

drivers/acpi/processor_perflib.c

+30 −0
Original line number Diff line number Diff line
@@ -324,6 +324,34 @@ static int acpi_processor_get_performance_control(struct acpi_processor *pr) 
	return result;

}



#ifdef CONFIG_X86

/*

 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding

 * in their ACPI data. Calculate the real values and fix up the _PSS data.

 */

static void amd_fixup_frequency(struct acpi_processor_px *px, int i)

{

	u32 hi, lo, fid, did;

	int index = px->control & 0x00000007;



	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)

		return;



	if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)

	    || boot_cpu_data.x86 == 0x11) {

		rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);

		fid = lo & 0x3f;

		did = (lo >> 6) & 7;

		if (boot_cpu_data.x86 == 0x10)

			px->core_frequency = (100 * (fid + 0x10)) >> did;

		else

			px->core_frequency = (100 * (fid + 8)) >> did;

	}

}

#else

static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {};

#endif



static int acpi_processor_get_performance_states(struct acpi_processor *pr)

{

	int result = 0;
@@ -379,6 +407,8 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr) 
			goto end;

		}



		amd_fixup_frequency(px, i);



		ACPI_DEBUG_PRINT((ACPI_DB_INFO,

				  "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",

				  i,