Commit b7b7c782 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar

perf/x86: Add an MSR PMU driver

This patch adds an MSR PMU to support free running MSR counters. Such
as time and freq related counters includes TSC, IA32_APERF, IA32_MPERF
and IA32_PPERF, but also SMI_COUNT.

The events are exposed in sysfs for use by perf stat and other tools.
The files are under /sys/devices/msr/events/
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
[ s/freq/msr/, added SMI_COUNT, fixed bugs. ]
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: adrian.hunter@intel.com
Cc: dsahern@gmail.com
Cc: eranian@google.com
Cc: jolsa@kernel.org
Cc: mark.rutland@arm.com
Cc: namhyung@kernel.org
Link: http://lkml.kernel.org/r/1437407346-31186-1-git-send-email-kan.liang@intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 070e9887
......@@ -46,6 +46,8 @@ obj-$(CONFIG_PERF_EVENTS_INTEL_UNCORE) += perf_event_intel_uncore.o \
perf_event_intel_uncore_snb.o \
perf_event_intel_uncore_snbep.o \
perf_event_intel_uncore_nhmex.o
obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_msr.o
obj-$(CONFIG_CPU_SUP_AMD) += perf_event_msr.o
endif
......
#include <linux/perf_event.h>
enum perf_msr_id {
PERF_MSR_TSC = 0,
PERF_MSR_APERF = 1,
PERF_MSR_MPERF = 2,
PERF_MSR_PPERF = 3,
PERF_MSR_SMI = 4,
PERF_MSR_EVENT_MAX,
};
struct perf_msr {
int id;
u64 msr;
};
static struct perf_msr msr[] = {
{ PERF_MSR_TSC, 0 },
{ PERF_MSR_APERF, MSR_IA32_APERF },
{ PERF_MSR_MPERF, MSR_IA32_MPERF },
{ PERF_MSR_PPERF, MSR_PPERF },
{ PERF_MSR_SMI, MSR_SMI_COUNT },
};
PMU_EVENT_ATTR_STRING(tsc, evattr_tsc, "event=0x00");
PMU_EVENT_ATTR_STRING(aperf, evattr_aperf, "event=0x01");
PMU_EVENT_ATTR_STRING(mperf, evattr_mperf, "event=0x02");
PMU_EVENT_ATTR_STRING(pperf, evattr_pperf, "event=0x03");
PMU_EVENT_ATTR_STRING(smi, evattr_smi, "event=0x04");
static struct attribute *events_attrs[PERF_MSR_EVENT_MAX + 1] = {
&evattr_tsc.attr.attr,
};
static struct attribute_group events_attr_group = {
.name = "events",
.attrs = events_attrs,
};
PMU_FORMAT_ATTR(event, "config:0-63");
static struct attribute *format_attrs[] = {
&format_attr_event.attr,
NULL,
};
static struct attribute_group format_attr_group = {
.name = "format",
.attrs = format_attrs,
};
static const struct attribute_group *attr_groups[] = {
&events_attr_group,
&format_attr_group,
NULL,
};
static int msr_event_init(struct perf_event *event)
{
u64 cfg = event->attr.config;
if (event->attr.type != event->pmu->type)
return -ENOENT;
if (cfg >= PERF_MSR_EVENT_MAX)
return -EINVAL;
/* unsupported modes and filters */
if (event->attr.exclude_user ||
event->attr.exclude_kernel ||
event->attr.exclude_hv ||
event->attr.exclude_idle ||
event->attr.exclude_host ||
event->attr.exclude_guest ||
event->attr.sample_period) /* no sampling */
return -EINVAL;
event->hw.idx = -1;
event->hw.event_base = msr[cfg].msr;
event->hw.config = cfg;
return 0;
}
static inline u64 msr_read_counter(struct perf_event *event)
{
u64 now;
if (event->hw.event_base)
rdmsrl(event->hw.event_base, now);
else
now = rdtsc();
return now;
}
static void msr_event_update(struct perf_event *event)
{
u64 prev, now;
s64 delta;
/* Careful, an NMI might modify the previous event value. */
again:
prev = local64_read(&event->hw.prev_count);
now = msr_read_counter(event);
if (local64_cmpxchg(&event->hw.prev_count, prev, now) != prev)
goto again;
delta = now - prev;
if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
delta <<= 32;
delta >>= 32; /* sign extend */
}
local64_add(now - prev, &event->count);
}
static void msr_event_start(struct perf_event *event, int flags)
{
u64 now;
now = msr_read_counter(event);
local64_set(&event->hw.prev_count, now);
}
static void msr_event_stop(struct perf_event *event, int flags)
{
msr_event_update(event);
}
static void msr_event_del(struct perf_event *event, int flags)
{
msr_event_stop(event, PERF_EF_UPDATE);
}
static int msr_event_add(struct perf_event *event, int flags)
{
if (flags & PERF_EF_START)
msr_event_start(event, flags);
return 0;
}
static struct pmu pmu_msr = {
.task_ctx_nr = perf_sw_context,
.attr_groups = attr_groups,
.event_init = msr_event_init,
.add = msr_event_add,
.del = msr_event_del,
.start = msr_event_start,
.stop = msr_event_stop,
.read = msr_event_update,
.capabilities = PERF_PMU_CAP_NO_INTERRUPT,
};
static int __init intel_msr_init(int idx)
{
if (boot_cpu_data.x86 != 6)
return 0;
switch (boot_cpu_data.x86_model) {
case 30: /* 45nm Nehalem */
case 26: /* 45nm Nehalem-EP */
case 46: /* 45nm Nehalem-EX */
case 37: /* 32nm Westmere */
case 44: /* 32nm Westmere-EP */
case 47: /* 32nm Westmere-EX */
case 42: /* 32nm SandyBridge */
case 45: /* 32nm SandyBridge-E/EN/EP */
case 58: /* 22nm IvyBridge */
case 62: /* 22nm IvyBridge-EP/EX */
case 60: /* 22nm Haswell Core */
case 63: /* 22nm Haswell Server */
case 69: /* 22nm Haswell ULT */
case 70: /* 22nm Haswell + GT3e (Intel Iris Pro graphics) */
case 61: /* 14nm Broadwell Core-M */
case 86: /* 14nm Broadwell Xeon D */
case 71: /* 14nm Broadwell + GT3e (Intel Iris Pro graphics) */
case 79: /* 14nm Broadwell Server */
events_attrs[idx++] = &evattr_smi.attr.attr;
break;
case 78: /* 14nm Skylake Mobile */
case 94: /* 14nm Skylake Desktop */
events_attrs[idx++] = &evattr_pperf.attr.attr;
events_attrs[idx++] = &evattr_smi.attr.attr;
break;
case 55: /* 22nm Atom "Silvermont" */
case 76: /* 14nm Atom "Airmont" */
case 77: /* 22nm Atom "Silvermont Avoton/Rangely" */
events_attrs[idx++] = &evattr_smi.attr.attr;
break;
}
events_attrs[idx] = NULL;
return 0;
}
static int __init amd_msr_init(int idx)
{
return 0;
}
static int __init msr_init(void)
{
int err;
int idx = 1;
if (boot_cpu_has(X86_FEATURE_APERFMPERF)) {
events_attrs[idx++] = &evattr_aperf.attr.attr;
events_attrs[idx++] = &evattr_mperf.attr.attr;
events_attrs[idx] = NULL;
}
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_INTEL:
err = intel_msr_init(idx);
break;
case X86_VENDOR_AMD:
err = amd_msr_init(idx);
break;
default:
err = -ENOTSUPP;
}
if (err != 0) {
pr_cont("no msr PMU driver.\n");
return 0;
}
perf_pmu_register(&pmu_msr, "msr", -1);
return 0;
}
device_initcall(msr_init);
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