From f594065faf4f9067c2283a34619fc0714e79a98d Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Tue, 4 Sep 2012 08:28:06 +0000 Subject: [PATCH] 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 Signed-off-by: Andre Przywara Signed-off-by: Rafael J. Wysocki --- arch/x86/include/asm/msr-index.h | 1 + drivers/acpi/processor_perflib.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 1e1f3eb58638..fbee9714d9ab 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -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 diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index a093dc163a42..836bfe069042 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -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, -- 2.39.5