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// SPDX-License-Identifier: GPL-2.0
#include <linux/perf_event.h>
#include <linux/nospec.h>
#include <asm/intel-family.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_PTSC = 5,
PERF_MSR_IRPERF = 6,
PERF_MSR_EVENT_MAX,
};
static bool test_aperfmperf(int idx)
{
return boot_cpu_has(X86_FEATURE_APERFMPERF);
}
static bool test_ptsc(int idx)
{
return boot_cpu_has(X86_FEATURE_PTSC);
}
static bool test_irperf(int idx)
{
return boot_cpu_has(X86_FEATURE_IRPERF);
}
static bool test_intel(int idx)
{
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
boot_cpu_data.x86 != 6)
return false;
switch (boot_cpu_data.x86_model) {
case INTEL_FAM6_NEHALEM:
case INTEL_FAM6_NEHALEM_G:
case INTEL_FAM6_NEHALEM_EP:
case INTEL_FAM6_NEHALEM_EX:
case INTEL_FAM6_WESTMERE:
case INTEL_FAM6_WESTMERE_EP:
case INTEL_FAM6_WESTMERE_EX:
case INTEL_FAM6_SANDYBRIDGE:
case INTEL_FAM6_SANDYBRIDGE_X:
case INTEL_FAM6_IVYBRIDGE:
case INTEL_FAM6_IVYBRIDGE_X:
case INTEL_FAM6_HASWELL_CORE:
case INTEL_FAM6_HASWELL_X:
case INTEL_FAM6_HASWELL_ULT:
case INTEL_FAM6_HASWELL_GT3E:
case INTEL_FAM6_BROADWELL_CORE:
case INTEL_FAM6_BROADWELL_XEON_D:
case INTEL_FAM6_BROADWELL_GT3E:
case INTEL_FAM6_BROADWELL_X:
case INTEL_FAM6_ATOM_SILVERMONT1:
case INTEL_FAM6_ATOM_SILVERMONT2:
case INTEL_FAM6_ATOM_AIRMONT:
case INTEL_FAM6_ATOM_GOLDMONT:
case INTEL_FAM6_ATOM_DENVERTON:
case INTEL_FAM6_ATOM_GEMINI_LAKE:
case INTEL_FAM6_XEON_PHI_KNL:
case INTEL_FAM6_XEON_PHI_KNM:
if (idx == PERF_MSR_SMI)
return true;
break;
case INTEL_FAM6_SKYLAKE_MOBILE:
case INTEL_FAM6_SKYLAKE_DESKTOP:
case INTEL_FAM6_SKYLAKE_X:
case INTEL_FAM6_KABYLAKE_MOBILE:
case INTEL_FAM6_KABYLAKE_DESKTOP:
if (idx == PERF_MSR_SMI || idx == PERF_MSR_PPERF)
return true;
break;
}
return false;
}
struct perf_msr {
u64 msr;
struct perf_pmu_events_attr *attr;
bool (*test)(int idx);
};
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");
PMU_EVENT_ATTR_STRING(ptsc, evattr_ptsc, "event=0x05");
PMU_EVENT_ATTR_STRING(irperf, evattr_irperf, "event=0x06");
static struct perf_msr msr[] = {
[PERF_MSR_TSC] = { 0, &evattr_tsc, NULL, },
[PERF_MSR_APERF] = { MSR_IA32_APERF, &evattr_aperf, test_aperfmperf, },
[PERF_MSR_MPERF] = { MSR_IA32_MPERF, &evattr_mperf, test_aperfmperf, },
[PERF_MSR_PPERF] = { MSR_PPERF, &evattr_pperf, test_intel, },
[PERF_MSR_SMI] = { MSR_SMI_COUNT, &evattr_smi, test_intel, },
[PERF_MSR_PTSC] = { MSR_F15H_PTSC, &evattr_ptsc, test_ptsc, },
[PERF_MSR_IRPERF] = { MSR_F17H_IRPERF, &evattr_irperf, test_irperf, },
};
static struct attribute *events_attrs[PERF_MSR_EVENT_MAX + 1] = {
NULL,
};
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;
/* 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;
if (cfg >= PERF_MSR_EVENT_MAX)
return -EINVAL;
cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX);
if (!msr[cfg].attr)
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
rdtscll(now);
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 = sign_extend64(delta, 31);
local64_add(delta, &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 msr_init(void)
{
int i, j = 0;
if (!boot_cpu_has(X86_FEATURE_TSC)) {
pr_cont("no MSR PMU driver.\n");
return 0;
}
/* Probe the MSRs. */
for (i = PERF_MSR_TSC + 1; i < PERF_MSR_EVENT_MAX; i++) {
u64 val;
/*
* Virt sucks arse; you cannot tell if a R/O MSR is present :/
*/
if (!msr[i].test(i) || rdmsrl_safe(msr[i].msr, &val))
msr[i].attr = NULL;
}
/* List remaining MSRs in the sysfs attrs. */
for (i = 0; i < PERF_MSR_EVENT_MAX; i++) {
if (msr[i].attr)
events_attrs[j++] = &msr[i].attr->attr.attr;
}
events_attrs[j] = NULL;
perf_pmu_register(&pmu_msr, "msr", -1);
return 0;
}
device_initcall(msr_init);