.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;
*/
#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;