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-rw-r--r--arch/x86/include/asm/perf_event_p4.h3
-rw-r--r--arch/x86/kernel/cpu/perf_event_p4.c28
2 files changed, 18 insertions, 13 deletions
diff --git a/arch/x86/include/asm/perf_event_p4.h b/arch/x86/include/asm/perf_event_p4.h
index 295e2ff18a6a..e2f6a99f14ab 100644
--- a/arch/x86/include/asm/perf_event_p4.h
+++ b/arch/x86/include/asm/perf_event_p4.h
@@ -20,6 +20,9 @@
#define ARCH_P4_MAX_ESCR (ARCH_P4_TOTAL_ESCR - ARCH_P4_RESERVED_ESCR)
#define ARCH_P4_MAX_CCCR (18)
+#define ARCH_P4_CNTRVAL_BITS (40)
+#define ARCH_P4_CNTRVAL_MASK ((1ULL << ARCH_P4_CNTRVAL_BITS) - 1)
+
#define P4_ESCR_EVENT_MASK 0x7e000000U
#define P4_ESCR_EVENT_SHIFT 25
#define P4_ESCR_EVENTMASK_MASK 0x01fffe00U
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index 81400b93e694..e56b9bfbabd1 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -753,19 +753,21 @@ out:
static inline int p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc)
{
- int overflow = 0;
- u32 low, high;
+ u64 v;
- rdmsr(hwc->config_base + hwc->idx, low, high);
-
- /* we need to check high bit for unflagged overflows */
- if ((low & P4_CCCR_OVF) || !(high & (1 << 31))) {
- overflow = 1;
- (void)checking_wrmsrl(hwc->config_base + hwc->idx,
- ((u64)low) & ~P4_CCCR_OVF);
+ /* an official way for overflow indication */
+ rdmsrl(hwc->config_base + hwc->idx, v);
+ if (v & P4_CCCR_OVF) {
+ wrmsrl(hwc->config_base + hwc->idx, v & ~P4_CCCR_OVF);
+ return 1;
}
- return overflow;
+ /* it might be unflagged overflow */
+ rdmsrl(hwc->event_base + hwc->idx, v);
+ if (!(v & ARCH_P4_CNTRVAL_MASK))
+ return 1;
+
+ return 0;
}
static void p4_pmu_disable_pebs(void)
@@ -1152,9 +1154,9 @@ static __initconst const struct x86_pmu p4_pmu = {
*/
.num_counters = ARCH_P4_MAX_CCCR,
.apic = 1,
- .cntval_bits = 40,
- .cntval_mask = (1ULL << 40) - 1,
- .max_period = (1ULL << 39) - 1,
+ .cntval_bits = ARCH_P4_CNTRVAL_BITS,
+ .cntval_mask = ARCH_P4_CNTRVAL_MASK,
+ .max_period = (1ULL << (ARCH_P4_CNTRVAL_BITS - 1)) - 1,
.hw_config = p4_hw_config,
.schedule_events = p4_pmu_schedule_events,
/*
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