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Diffstat (limited to 'arch/x86/events/amd/ibs.c')
-rw-r--r--arch/x86/events/amd/ibs.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 26c36357c4c9..a023cbe21230 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -89,6 +89,7 @@ struct perf_ibs {
u64 max_period;
unsigned long offset_mask[1];
int offset_max;
+ unsigned int fetch_count_reset_broken : 1;
struct cpu_perf_ibs __percpu *pcpu;
struct attribute **format_attrs;
@@ -363,7 +364,12 @@ perf_ibs_event_update(struct perf_ibs *perf_ibs, struct perf_event *event,
static inline void perf_ibs_enable_event(struct perf_ibs *perf_ibs,
struct hw_perf_event *hwc, u64 config)
{
- wrmsrl(hwc->config_base, hwc->config | config | perf_ibs->enable_mask);
+ u64 tmp = hwc->config | config;
+
+ if (perf_ibs->fetch_count_reset_broken)
+ wrmsrl(hwc->config_base, tmp & ~perf_ibs->enable_mask);
+
+ wrmsrl(hwc->config_base, tmp | perf_ibs->enable_mask);
}
/*
@@ -733,6 +739,13 @@ static __init void perf_event_ibs_init(void)
{
struct attribute **attr = ibs_op_format_attrs;
+ /*
+ * Some chips fail to reset the fetch count when it is written; instead
+ * they need a 0-1 transition of IbsFetchEn.
+ */
+ if (boot_cpu_data.x86 >= 0x16 && boot_cpu_data.x86 <= 0x18)
+ perf_ibs_fetch.fetch_count_reset_broken = 1;
+
perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch");
if (ibs_caps & IBS_CAPS_OPCNT) {