diff options
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event_p4.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_p4.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c index f7a0993c1e7..3769ac822f9 100644 --- a/arch/x86/kernel/cpu/perf_event_p4.c +++ b/arch/x86/kernel/cpu/perf_event_p4.c @@ -764,15 +764,20 @@ static inline int p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc) u64 v; /* an official way for overflow indication */ - rdmsrl(hwc->config_base + hwc->idx, v); + rdmsrl(hwc->config_base, v); if (v & P4_CCCR_OVF) { - wrmsrl(hwc->config_base + hwc->idx, v & ~P4_CCCR_OVF); + wrmsrl(hwc->config_base, v & ~P4_CCCR_OVF); return 1; } - /* it might be unflagged overflow */ - rdmsrl(hwc->event_base + hwc->idx, v); - if (!(v & ARCH_P4_CNTRVAL_MASK)) + /* + * In some circumstances the overflow might issue an NMI but did + * not set P4_CCCR_OVF bit. Because a counter holds a negative value + * we simply check for high bit being set, if it's cleared it means + * the counter has reached zero value and continued counting before + * real NMI signal was received: + */ + if (!(v & ARCH_P4_UNFLAGGED_BIT)) return 1; return 0; @@ -810,7 +815,7 @@ static inline void p4_pmu_disable_event(struct perf_event *event) * state we need to clear P4_CCCR_OVF, otherwise interrupt get * asserted again and again */ - (void)checking_wrmsrl(hwc->config_base + hwc->idx, + (void)checking_wrmsrl(hwc->config_base, (u64)(p4_config_unpack_cccr(hwc->config)) & ~P4_CCCR_ENABLE & ~P4_CCCR_OVF & ~P4_CCCR_RESERVED); } @@ -880,7 +885,7 @@ static void p4_pmu_enable_event(struct perf_event *event) p4_pmu_enable_pebs(hwc->config); (void)checking_wrmsrl(escr_addr, escr_conf); - (void)checking_wrmsrl(hwc->config_base + hwc->idx, + (void)checking_wrmsrl(hwc->config_base, (cccr & ~P4_CCCR_RESERVED) | P4_CCCR_ENABLE); } |