From 6a35fc2d6c22bafe45117cdc5d8cee332244edbb Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Wed, 14 Oct 2015 16:11:59 -0700 Subject: [PATCH] cpufreq: intel_pstate: get P1 from TAR when available After Ivybridge, the max non turbo ratio obtained from platform info msr is not always guaranteed P1 on client platforms. The max non turbo activation ratio (TAR), determines the max for the current level of TDP. The ratio in platform info is physical max. The TAR MSR can be locked, so updating this value is not possible on all platforms. This change gets this ratio from MSR TURBO_ACTIVATION_RATIO if available, but also do some sanity checking to make sure that this value is correct. The sanity check involves reading the TDP ratio for the current tdp control value when platform has configurable TDP present and matching TAC with this. Signed-off-by: Srinivas Pandruvada Acked-by: Kristen Carlson Accardi Signed-off-by: Rafael J. Wysocki --- arch/x86/include/asm/msr-index.h | 7 ++++++ drivers/cpufreq/intel_pstate.c | 39 ++++++++++++++++++++++++++++---- 2 files changed, 42 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index b8c14bb7fc8f..9f3905697f12 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -206,6 +206,13 @@ #define MSR_GFX_PERF_LIMIT_REASONS 0x000006B0 #define MSR_RING_PERF_LIMIT_REASONS 0x000006B1 +/* Config TDP MSRs */ +#define MSR_CONFIG_TDP_NOMINAL 0x00000648 +#define MSR_CONFIG_TDP_LEVEL1 0x00000649 +#define MSR_CONFIG_TDP_LEVEL2 0x0000064A +#define MSR_CONFIG_TDP_CONTROL 0x0000064B +#define MSR_TURBO_ACTIVATION_RATIO 0x0000064C + /* Hardware P state interface */ #define MSR_PPERF 0x0000064e #define MSR_PERF_LIMIT_REASONS 0x0000064f diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 3af9dd7332e6..da92d0201d52 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -43,7 +43,6 @@ #define int_tofp(X) ((int64_t)(X) << FRAC_BITS) #define fp_toint(X) ((X) >> FRAC_BITS) - static inline int32_t mul_fp(int32_t x, int32_t y) { return ((int64_t)x * (int64_t)y) >> FRAC_BITS; @@ -593,10 +592,42 @@ static int core_get_min_pstate(void) static int core_get_max_pstate(void) { - u64 value; + u64 tar; + u64 plat_info; + int max_pstate; + int err; + + rdmsrl(MSR_PLATFORM_INFO, plat_info); + max_pstate = (plat_info >> 8) & 0xFF; + + err = rdmsrl_safe(MSR_TURBO_ACTIVATION_RATIO, &tar); + if (!err) { + /* Do some sanity checking for safety */ + if (plat_info & 0x600000000) { + u64 tdp_ctrl; + u64 tdp_ratio; + int tdp_msr; + + err = rdmsrl_safe(MSR_CONFIG_TDP_CONTROL, &tdp_ctrl); + if (err) + goto skip_tar; + + tdp_msr = MSR_CONFIG_TDP_NOMINAL + tdp_ctrl; + err = rdmsrl_safe(tdp_msr, &tdp_ratio); + if (err) + goto skip_tar; + + if (tdp_ratio - 1 == tar) { + max_pstate = tar; + pr_debug("max_pstate=TAC %x\n", max_pstate); + } else { + goto skip_tar; + } + } + } - rdmsrl(MSR_PLATFORM_INFO, value); - return (value >> 8) & 0xFF; +skip_tar: + return max_pstate; } static int core_get_turbo_pstate(void) -- GitLab