ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/x86/kernel/cpu/aperfmperf.c b/marvell/linux/arch/x86/kernel/cpu/aperfmperf.c
new file mode 100644
index 0000000..e2f319d
--- /dev/null
+++ b/marvell/linux/arch/x86/kernel/cpu/aperfmperf.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * x86 APERF/MPERF KHz calculation for
+ * /sys/.../cpufreq/scaling_cur_freq
+ *
+ * Copyright (C) 2017 Intel Corp.
+ * Author: Len Brown <len.brown@intel.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/ktime.h>
+#include <linux/math64.h>
+#include <linux/percpu.h>
+#include <linux/cpufreq.h>
+#include <linux/smp.h>
+#include <linux/sched/isolation.h>
+
+#include "cpu.h"
+
+struct aperfmperf_sample {
+ unsigned int khz;
+ 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);
+}
+
+static bool aperfmperf_snapshot_cpu(int cpu, ktime_t now, bool wait)
+{
+ s64 time_delta = ktime_ms_delta(now, per_cpu(samples.time, cpu));
+
+ /* Don't bother re-computing within the cache threshold time. */
+ if (time_delta < APERFMPERF_CACHE_THRESHOLD_MS)
+ return true;
+
+ 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 aperfmperf_get_khz(int cpu)
+{
+ if (!cpu_khz)
+ return 0;
+
+ if (!boot_cpu_has(X86_FEATURE_APERFMPERF))
+ return 0;
+
+ if (!housekeeping_cpu(cpu, HK_FLAG_MISC))
+ return 0;
+
+ aperfmperf_snapshot_cpu(cpu, ktime_get(), true);
+ return per_cpu(samples.khz, cpu);
+}
+
+void arch_freq_prepare_all(void)
+{
+ ktime_t now = ktime_get();
+ bool wait = false;
+ int cpu;
+
+ if (!cpu_khz)
+ return;
+
+ if (!boot_cpu_has(X86_FEATURE_APERFMPERF))
+ return;
+
+ for_each_online_cpu(cpu) {
+ if (!housekeeping_cpu(cpu, HK_FLAG_MISC))
+ continue;
+ if (!aperfmperf_snapshot_cpu(cpu, now, false))
+ wait = true;
+ }
+
+ if (wait)
+ msleep(APERFMPERF_REFRESH_DELAY_MS);
+}
+
+unsigned int arch_freq_get_on_cpu(int cpu)
+{
+ if (!cpu_khz)
+ return 0;
+
+ if (!boot_cpu_has(X86_FEATURE_APERFMPERF))
+ return 0;
+
+ if (!housekeeping_cpu(cpu, HK_FLAG_MISC))
+ return 0;
+
+ if (aperfmperf_snapshot_cpu(cpu, ktime_get(), true))
+ return per_cpu(samples.khz, cpu);
+
+ msleep(APERFMPERF_REFRESH_DELAY_MS);
+ smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, 1);
+
+ return per_cpu(samples.khz, cpu);
+}