[PATCH 2/8] perf/x86/msr: Use new probe function

From: Jiri Olsa
Date: Sun Jun 16 2019 - 10:09:05 EST


Using perf_msr_probe function to probe for msr events.

The functionality is the same, with one exception, that
perf_msr_probe checks for rdmsr to return value != 0 for
given MSR register.

Using the new attribute groups and adding the events via
pmu::attr_update.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
arch/x86/events/msr.c | 110 +++++++++++++++++++++++-------------------
1 file changed, 60 insertions(+), 50 deletions(-)

diff --git a/arch/x86/events/msr.c b/arch/x86/events/msr.c
index f3f4c2263501..9431447541e9 100644
--- a/arch/x86/events/msr.c
+++ b/arch/x86/events/msr.c
@@ -1,7 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/perf_event.h>
+#include <linux/sysfs.h>
#include <linux/nospec.h>
#include <asm/intel-family.h>
+#include "probe.h"

enum perf_msr_id {
PERF_MSR_TSC = 0,
@@ -12,32 +14,30 @@ enum perf_msr_id {
PERF_MSR_PTSC = 5,
PERF_MSR_IRPERF = 6,
PERF_MSR_THERM = 7,
- PERF_MSR_THERM_SNAP = 8,
- PERF_MSR_THERM_UNIT = 9,
PERF_MSR_EVENT_MAX,
};

-static bool test_aperfmperf(int idx)
+static bool test_aperfmperf(int idx, void *data)
{
return boot_cpu_has(X86_FEATURE_APERFMPERF);
}

-static bool test_ptsc(int idx)
+static bool test_ptsc(int idx, void *data)
{
return boot_cpu_has(X86_FEATURE_PTSC);
}

-static bool test_irperf(int idx)
+static bool test_irperf(int idx, void *data)
{
return boot_cpu_has(X86_FEATURE_IRPERF);
}

-static bool test_therm_status(int idx)
+static bool test_therm_status(int idx, void *data)
{
return boot_cpu_has(X86_FEATURE_DTHERM);
}

-static bool test_intel(int idx)
+static bool test_intel(int idx, void *data)
{
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
boot_cpu_data.x86 != 6)
@@ -98,37 +98,51 @@ static bool test_intel(int idx)
return false;
}

-struct perf_msr {
- u64 msr;
- struct perf_pmu_events_attr *attr;
- bool (*test)(int idx);
+PMU_EVENT_ATTR_STRING(tsc, attr_tsc, "event=0x00" );
+PMU_EVENT_ATTR_STRING(aperf, attr_aperf, "event=0x01" );
+PMU_EVENT_ATTR_STRING(mperf, attr_mperf, "event=0x02" );
+PMU_EVENT_ATTR_STRING(pperf, attr_pperf, "event=0x03" );
+PMU_EVENT_ATTR_STRING(smi, attr_smi, "event=0x04" );
+PMU_EVENT_ATTR_STRING(ptsc, attr_ptsc, "event=0x05" );
+PMU_EVENT_ATTR_STRING(irperf, attr_irperf, "event=0x06" );
+PMU_EVENT_ATTR_STRING(cpu_thermal_margin, attr_therm, "event=0x07" );
+PMU_EVENT_ATTR_STRING(cpu_thermal_margin.snapshot, attr_therm_snap, "1" );
+PMU_EVENT_ATTR_STRING(cpu_thermal_margin.unit, attr_therm_unit, "C" );
+
+static unsigned long msr_mask;
+
+PMU_EVENT_GROUP(events, aperf);
+PMU_EVENT_GROUP(events, mperf);
+PMU_EVENT_GROUP(events, pperf);
+PMU_EVENT_GROUP(events, smi);
+PMU_EVENT_GROUP(events, ptsc);
+PMU_EVENT_GROUP(events, irperf);
+
+static struct attribute *attrs_therm[] = {
+ &attr_therm.attr.attr,
+ &attr_therm_snap.attr.attr,
+ &attr_therm_unit.attr.attr,
+ NULL,
};

-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" );
-PMU_EVENT_ATTR_STRING(cpu_thermal_margin, evattr_therm, "event=0x07" );
-PMU_EVENT_ATTR_STRING(cpu_thermal_margin.snapshot, evattr_therm_snap, "1" );
-PMU_EVENT_ATTR_STRING(cpu_thermal_margin.unit, evattr_therm_unit, "C" );
+static struct attribute_group group_therm = {
+ .name = "events",
+ .attrs = attrs_therm,
+};

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, },
- [PERF_MSR_THERM] = { MSR_IA32_THERM_STATUS, &evattr_therm, test_therm_status, },
- [PERF_MSR_THERM_SNAP] = { MSR_IA32_THERM_STATUS, &evattr_therm_snap, test_therm_status, },
- [PERF_MSR_THERM_UNIT] = { MSR_IA32_THERM_STATUS, &evattr_therm_unit, test_therm_status, },
+ [PERF_MSR_TSC] = { .no_check = true, },
+ [PERF_MSR_APERF] = { MSR_IA32_APERF, &group_aperf, test_aperfmperf, },
+ [PERF_MSR_MPERF] = { MSR_IA32_MPERF, &group_mperf, test_aperfmperf, },
+ [PERF_MSR_PPERF] = { MSR_PPERF, &group_pperf, test_intel, },
+ [PERF_MSR_SMI] = { MSR_SMI_COUNT, &group_smi, test_intel, },
+ [PERF_MSR_PTSC] = { MSR_F15H_PTSC, &group_ptsc, test_ptsc, },
+ [PERF_MSR_IRPERF] = { MSR_F17H_IRPERF, &group_irperf, test_irperf, },
+ [PERF_MSR_THERM] = { MSR_IA32_THERM_STATUS, &group_therm, test_therm_status, },
};

-static struct attribute *events_attrs[PERF_MSR_EVENT_MAX + 1] = {
+static struct attribute *events_attrs[] = {
+ &attr_tsc.attr.attr,
NULL,
};

@@ -153,6 +167,17 @@ static const struct attribute_group *attr_groups[] = {
NULL,
};

+const struct attribute_group *attr_update[] = {
+ &group_aperf,
+ &group_mperf,
+ &group_pperf,
+ &group_smi,
+ &group_ptsc,
+ &group_irperf,
+ &group_therm,
+ NULL,
+};
+
static int msr_event_init(struct perf_event *event)
{
u64 cfg = event->attr.config;
@@ -169,7 +194,7 @@ static int msr_event_init(struct perf_event *event)

cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX);

- if (!msr[cfg].attr)
+ if (!(msr_mask & (1 << cfg)))
return -EINVAL;

event->hw.idx = -1;
@@ -252,32 +277,17 @@ static struct pmu pmu_msr = {
.stop = msr_event_stop,
.read = msr_event_update,
.capabilities = PERF_PMU_CAP_NO_INTERRUPT | PERF_PMU_CAP_NO_EXCLUDE,
+ .attr_update = attr_update,
};

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; 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;
+ msr_mask = perf_msr_probe(msr, PERF_MSR_EVENT_MAX, true, NULL);

perf_pmu_register(&pmu_msr, "msr", -1);

--
2.21.0