diff options
Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 36953b5f18de..19712e27ad50 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -49,6 +49,9 @@ #define int_tofp(X) ((int64_t)(X) << FRAC_BITS) #define fp_toint(X) ((X) >> FRAC_BITS) +#define EXT_BITS 6 +#define EXT_FRAC_BITS (EXT_BITS + FRAC_BITS) + static inline int32_t mul_fp(int32_t x, int32_t y) { return ((int64_t)x * (int64_t)y) >> FRAC_BITS; @@ -70,12 +73,22 @@ static inline int ceiling_fp(int32_t x) return ret; } +static inline u64 mul_ext_fp(u64 x, u64 y) +{ + return (x * y) >> EXT_FRAC_BITS; +} + +static inline u64 div_ext_fp(u64 x, u64 y) +{ + return div64_u64(x << EXT_FRAC_BITS, y); +} + /** * struct sample - Store performance sample - * @core_pct_busy: Ratio of APERF/MPERF in percent, which is actual + * @core_avg_perf: Ratio of APERF/MPERF which is the actual average * performance during last sample period * @busy_scaled: Scaled busy value which is used to calculate next - * P state. This can be different than core_pct_busy + * P state. This can be different than core_avg_perf * to account for cpu idle period * @aperf: Difference of actual performance frequency clock count * read from APERF MSR between last and current sample @@ -90,7 +103,7 @@ static inline int ceiling_fp(int32_t x) * data for choosing next P State. */ struct sample { - int32_t core_pct_busy; + int32_t core_avg_perf; int32_t busy_scaled; u64 aperf; u64 mperf; @@ -1152,15 +1165,11 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) intel_pstate_set_min_pstate(cpu); } -static inline void intel_pstate_calc_busy(struct cpudata *cpu) +static inline void intel_pstate_calc_avg_perf(struct cpudata *cpu) { struct sample *sample = &cpu->sample; - int64_t core_pct; - - core_pct = sample->aperf * int_tofp(100); - core_pct = div64_u64(core_pct, sample->mperf); - sample->core_pct_busy = (int32_t)core_pct; + sample->core_avg_perf = div_ext_fp(sample->aperf, sample->mperf); } static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time) @@ -1203,9 +1212,8 @@ static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time) static inline int32_t get_avg_frequency(struct cpudata *cpu) { - return fp_toint(mul_fp(cpu->sample.core_pct_busy, - int_tofp(cpu->pstate.max_pstate_physical * - cpu->pstate.scaling / 100))); + return mul_ext_fp(cpu->sample.core_avg_perf, + cpu->pstate.max_pstate_physical * cpu->pstate.scaling); } static inline int32_t get_avg_pstate(struct cpudata *cpu) @@ -1265,10 +1273,10 @@ static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu) * period. The result will be a percentage of busy at a * specified pstate. */ - core_busy = cpu->sample.core_pct_busy; max_pstate = cpu->pstate.max_pstate_physical; current_pstate = cpu->pstate.current_pstate; - core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate)); + core_busy = mul_ext_fp(cpu->sample.core_avg_perf, + div_fp(100 * max_pstate, current_pstate)); /* * Since our utilization update callback will not run unless we are @@ -1317,7 +1325,7 @@ static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu) intel_pstate_update_pstate(cpu, target_pstate); sample = &cpu->sample; - trace_pstate_sample(fp_toint(sample->core_pct_busy), + trace_pstate_sample(mul_ext_fp(100, sample->core_avg_perf), fp_toint(sample->busy_scaled), from, cpu->pstate.current_pstate, @@ -1337,7 +1345,7 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time, bool sample_taken = intel_pstate_sample(cpu, time); if (sample_taken) { - intel_pstate_calc_busy(cpu); + intel_pstate_calc_avg_perf(cpu); if (!hwp_active) intel_pstate_adjust_busy_pstate(cpu); } |