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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: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Matthew Garrett 2012-09-04 08:28:06 +00:00 committed by Rafael J. Wysocki
parent a206095856
commit f594065faf
2 changed files with 31 additions and 0 deletions
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1
arch/x86/include/asm/msr-index.h
View File

@ -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

30
drivers/acpi/processor_perflib.c
View File

@ -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,