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Diffstat (limited to 'arch/x86/kernel/cpu/perf_counter.c')
-rw-r--r--arch/x86/kernel/cpu/perf_counter.c40
1 files changed, 33 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index a7aa8f90095..900332b800f 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -55,6 +55,7 @@ struct x86_pmu {
int num_counters_fixed;
int counter_bits;
u64 counter_mask;
+ int apic;
u64 max_period;
u64 intel_ctrl;
};
@@ -72,8 +73,8 @@ static const u64 p6_perfmon_event_map[] =
{
[PERF_COUNT_HW_CPU_CYCLES] = 0x0079,
[PERF_COUNT_HW_INSTRUCTIONS] = 0x00c0,
- [PERF_COUNT_HW_CACHE_REFERENCES] = 0x0000,
- [PERF_COUNT_HW_CACHE_MISSES] = 0x0000,
+ [PERF_COUNT_HW_CACHE_REFERENCES] = 0x0f2e,
+ [PERF_COUNT_HW_CACHE_MISSES] = 0x012e,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x00c4,
[PERF_COUNT_HW_BRANCH_MISSES] = 0x00c5,
[PERF_COUNT_HW_BUS_CYCLES] = 0x0062,
@@ -613,6 +614,7 @@ static DEFINE_MUTEX(pmc_reserve_mutex);
static bool reserve_pmc_hardware(void)
{
+#ifdef CONFIG_X86_LOCAL_APIC
int i;
if (nmi_watchdog == NMI_LOCAL_APIC)
@@ -627,9 +629,11 @@ static bool reserve_pmc_hardware(void)
if (!reserve_evntsel_nmi(x86_pmu.eventsel + i))
goto eventsel_fail;
}
+#endif
return true;
+#ifdef CONFIG_X86_LOCAL_APIC
eventsel_fail:
for (i--; i >= 0; i--)
release_evntsel_nmi(x86_pmu.eventsel + i);
@@ -644,10 +648,12 @@ perfctr_fail:
enable_lapic_nmi_watchdog();
return false;
+#endif
}
static void release_pmc_hardware(void)
{
+#ifdef CONFIG_X86_LOCAL_APIC
int i;
for (i = 0; i < x86_pmu.num_counters; i++) {
@@ -657,6 +663,7 @@ static void release_pmc_hardware(void)
if (nmi_watchdog == NMI_LOCAL_APIC)
enable_lapic_nmi_watchdog();
+#endif
}
static void hw_perf_counter_destroy(struct perf_counter *counter)
@@ -748,6 +755,15 @@ static int __hw_perf_counter_init(struct perf_counter *counter)
hwc->sample_period = x86_pmu.max_period;
hwc->last_period = hwc->sample_period;
atomic64_set(&hwc->period_left, hwc->sample_period);
+ } else {
+ /*
+ * If we have a PMU initialized but no APIC
+ * interrupts, we cannot sample hardware
+ * counters (user-space has to fall back and
+ * sample via a hrtimer based software counter):
+ */
+ if (!x86_pmu.apic)
+ return -EOPNOTSUPP;
}
counter->destroy = hw_perf_counter_destroy;
@@ -1449,18 +1465,22 @@ void smp_perf_pending_interrupt(struct pt_regs *regs)
void set_perf_counter_pending(void)
{
+#ifdef CONFIG_X86_LOCAL_APIC
apic->send_IPI_self(LOCAL_PENDING_VECTOR);
+#endif
}
void perf_counters_lapic_init(void)
{
- if (!x86_pmu_initialized())
+#ifdef CONFIG_X86_LOCAL_APIC
+ if (!x86_pmu.apic || !x86_pmu_initialized())
return;
/*
* Always use NMI for PMU
*/
apic_write(APIC_LVTPC, APIC_DM_NMI);
+#endif
}
static int __kprobes
@@ -1484,7 +1504,9 @@ perf_counter_nmi_handler(struct notifier_block *self,
regs = args->regs;
+#ifdef CONFIG_X86_LOCAL_APIC
apic_write(APIC_LVTPC, APIC_DM_NMI);
+#endif
/*
* Can't rely on the handled return value to say it was our NMI, two
* counters could trigger 'simultaneously' raising two back-to-back NMIs.
@@ -1515,6 +1537,7 @@ static struct x86_pmu p6_pmu = {
.event_map = p6_pmu_event_map,
.raw_event = p6_pmu_raw_event,
.max_events = ARRAY_SIZE(p6_perfmon_event_map),
+ .apic = 1,
.max_period = (1ULL << 31) - 1,
.version = 0,
.num_counters = 2,
@@ -1541,6 +1564,7 @@ static struct x86_pmu intel_pmu = {
.event_map = intel_pmu_event_map,
.raw_event = intel_pmu_raw_event,
.max_events = ARRAY_SIZE(intel_perfmon_event_map),
+ .apic = 1,
/*
* Intel PMCs cannot be accessed sanely above 32 bit width,
* so we install an artificial 1<<31 period regardless of
@@ -1564,6 +1588,7 @@ static struct x86_pmu amd_pmu = {
.num_counters = 4,
.counter_bits = 48,
.counter_mask = (1ULL << 48) - 1,
+ .apic = 1,
/* use highest bit to detect overflow */
.max_period = (1ULL << 47) - 1,
};
@@ -1589,13 +1614,14 @@ static int p6_pmu_init(void)
return -ENODEV;
}
+ x86_pmu = p6_pmu;
+
if (!cpu_has_apic) {
- pr_info("no Local APIC, try rebooting with lapic");
- return -ENODEV;
+ pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
+ pr_info("no hardware sampling interrupt available.\n");
+ x86_pmu.apic = 0;
}
- x86_pmu = p6_pmu;
-
return 0;
}