diff --git a/arch/x86/kernel/cpu/aperfmperf.c b/arch/x86/kernel/cpu/aperfmperf.c index e9d2da7effc9..b15c884c4cbf 100644 --- a/arch/x86/kernel/cpu/aperfmperf.c +++ b/arch/x86/kernel/cpu/aperfmperf.c @@ -36,98 +36,6 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct aperfmperf, cpu_samples) = { .seq = SEQCNT_ZERO(cpu_samples.seq) }; -struct aperfmperf_sample { - unsigned int khz; - atomic_t scfpending; - ktime_t time; - u64 aperf; - u64 mperf; -}; - -static DEFINE_PER_CPU(struct aperfmperf_sample, samples); - -#define APERFMPERF_CACHE_THRESHOLD_MS 10 -#define APERFMPERF_REFRESH_DELAY_MS 10 -#define APERFMPERF_STALE_THRESHOLD_MS 1000 - -/* - * aperfmperf_snapshot_khz() - * On the current CPU, snapshot APERF, MPERF, and jiffies - * unless we already did it within 10ms - * calculate kHz, save snapshot - */ -static void aperfmperf_snapshot_khz(void *dummy) -{ - u64 aperf, aperf_delta; - u64 mperf, mperf_delta; - struct aperfmperf_sample *s = this_cpu_ptr(&samples); - unsigned long flags; - - local_irq_save(flags); - rdmsrl(MSR_IA32_APERF, aperf); - rdmsrl(MSR_IA32_MPERF, mperf); - local_irq_restore(flags); - - aperf_delta = aperf - s->aperf; - mperf_delta = mperf - s->mperf; - - /* - * There is no architectural guarantee that MPERF - * increments faster than we can read it. - */ - if (mperf_delta == 0) - return; - - s->time = ktime_get(); - s->aperf = aperf; - s->mperf = mperf; - s->khz = div64_u64((cpu_khz * aperf_delta), mperf_delta); - atomic_set_release(&s->scfpending, 0); -} - -static bool aperfmperf_snapshot_cpu(int cpu, ktime_t now, bool wait) -{ - s64 time_delta = ktime_ms_delta(now, per_cpu(samples.time, cpu)); - struct aperfmperf_sample *s = per_cpu_ptr(&samples, cpu); - - /* Don't bother re-computing within the cache threshold time. */ - if (time_delta < APERFMPERF_CACHE_THRESHOLD_MS) - return true; - - if (!atomic_xchg(&s->scfpending, 1) || wait) - smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, wait); - - /* Return false if the previous iteration was too long ago. */ - return time_delta <= APERFMPERF_STALE_THRESHOLD_MS; -} - -unsigned int arch_freq_get_on_cpu(int cpu) -{ - struct aperfmperf_sample *s = per_cpu_ptr(&samples, cpu); - - if (!cpu_khz) - return 0; - - if (!boot_cpu_has(X86_FEATURE_APERFMPERF)) - return 0; - - if (!housekeeping_cpu(cpu, HK_TYPE_MISC)) - return 0; - - if (rcu_is_idle_cpu(cpu)) - return 0; - - if (aperfmperf_snapshot_cpu(cpu, ktime_get(), true)) - return per_cpu(samples.khz, cpu); - - msleep(APERFMPERF_REFRESH_DELAY_MS); - atomic_set(&s->scfpending, 1); - smp_mb(); /* ->scfpending before smp_call_function_single(). */ - smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, 1); - - return per_cpu(samples.khz, cpu); -} - static void init_counter_refs(void) { u64 aperf, mperf; @@ -494,7 +402,7 @@ void arch_scale_freq_tick(void) */ #define MAX_SAMPLE_AGE ((unsigned long)HZ / 50) -unsigned int aperfmperf_get_khz(int cpu) +unsigned int arch_freq_get_on_cpu(int cpu) { struct aperfmperf *s = per_cpu_ptr(&cpu_samples, cpu); unsigned long last; diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c index 4eec8889b0ff..0a0ee55830c7 100644 --- a/arch/x86/kernel/cpu/proc.c +++ b/arch/x86/kernel/cpu/proc.c @@ -84,7 +84,7 @@ static int show_cpuinfo(struct seq_file *m, void *v) seq_printf(m, "microcode\t: 0x%x\n", c->microcode); if (cpu_has(c, X86_FEATURE_TSC)) { - unsigned int freq = aperfmperf_get_khz(cpu); + unsigned int freq = arch_freq_get_on_cpu(cpu); if (!freq) freq = cpufreq_quick_get(cpu);