diff options
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/perf_counter.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c index bd6ba85beb54..6e27913ec0d8 100644 --- a/arch/powerpc/kernel/perf_counter.c +++ b/arch/powerpc/kernel/perf_counter.c @@ -32,6 +32,15 @@ DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters); struct power_pmu *ppmu; +/* + * Normally, to ignore kernel events we set the FCS (freeze counters + * in supervisor mode) bit in MMCR0, but if the kernel runs with the + * hypervisor bit set in the MSR, or if we are running on a processor + * where the hypervisor bit is forced to 1 (as on Apple G5 processors), + * then we need to use the FCHV bit to ignore kernel events. + */ +static unsigned int freeze_counters_kernel = MMCR0_FCS; + void perf_counter_print_debug(void) { } @@ -364,7 +373,7 @@ void hw_perf_restore(u64 disable) if (counter->hw_event.exclude_user) cpuhw->mmcr[0] |= MMCR0_FCP; if (counter->hw_event.exclude_kernel) - cpuhw->mmcr[0] |= MMCR0_FCS; + cpuhw->mmcr[0] |= freeze_counters_kernel; if (counter->hw_event.exclude_hv) cpuhw->mmcr[0] |= MMCR0_FCHV; @@ -606,10 +615,7 @@ hw_perf_counter_init(struct perf_counter *counter) /* * If we are not running on a hypervisor, force the * exclude_hv bit to 0 so that we don't care what - * the user set it to. This also means that we don't - * set the MMCR0_FCHV bit, which unconditionally freezes - * the counters on the PPC970 variants used in Apple G5 - * machines (since MSR.HV is always 1 on those machines). + * the user set it to. */ if (!firmware_has_feature(FW_FEATURE_LPAR)) counter->hw_event.exclude_hv = 0; @@ -841,6 +847,13 @@ static int init_perf_counters(void) ppmu = &power6_pmu; break; } + + /* + * Use FCHV to ignore kernel events if MSR.HV is set. + */ + if (mfmsr() & MSR_HV) + freeze_counters_kernel = MMCR0_FCHV; + return 0; } |
