From d2caa3cebda8b626336e100b80a0ed6f909dccab Mon Sep 17 00:00:00 2001 From: Tom Huynh Date: Tue, 20 Jan 2015 16:19:50 -0600 Subject: powerpc/perf: fix fsl_emb_pmu_start to write correct pmc value PMCs on PowerPC increases towards 0x80000000 and triggers an overflow interrupt when the msb is set to collect a sample. Therefore, to setup for the next sample collection, pmu_start should set the pmc value to 0x80000000 - left instead of left which incorrectly delays the next overflow interrupt. Same as commit 9a45a9407c69 ("powerpc/perf: power_pmu_start restores incorrect values, breaking frequency events") for book3s. Signed-off-by: Tom Huynh Signed-off-by: Scott Wood --- arch/powerpc/perf/core-fsl-emb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/perf') diff --git a/arch/powerpc/perf/core-fsl-emb.c b/arch/powerpc/perf/core-fsl-emb.c index 4acaea01fe03..e9fe904b6538 100644 --- a/arch/powerpc/perf/core-fsl-emb.c +++ b/arch/powerpc/perf/core-fsl-emb.c @@ -389,6 +389,7 @@ static void fsl_emb_pmu_del(struct perf_event *event, int flags) static void fsl_emb_pmu_start(struct perf_event *event, int ef_flags) { unsigned long flags; + unsigned long val; s64 left; if (event->hw.idx < 0 || !event->hw.sample_period) @@ -405,7 +406,10 @@ static void fsl_emb_pmu_start(struct perf_event *event, int ef_flags) event->hw.state = 0; left = local64_read(&event->hw.period_left); - write_pmc(event->hw.idx, left); + val = 0; + if (left < 0x80000000L) + val = 0x80000000L - left; + write_pmc(event->hw.idx, val); perf_event_update_userpage(event); perf_pmu_enable(event->pmu); -- cgit v1.2.3 From 0d7d9b3a456aa8670cd9552f69529d57716f3122 Mon Sep 17 00:00:00 2001 From: Alexandru-Cezar Sardan Date: Thu, 26 Jun 2014 11:58:58 +0300 Subject: perf/powerpc: reset event hw state when adding it to the PMU When adding an event to the PMU with PERF_EF_START the STOPPED and UPTODATE flags need to be cleared in the hw.event status variable because they are preventing the update of the event count on overflow interrupt. Signed-off-by: Alexandru-Cezar Sardan Signed-off-by: Scott Wood --- arch/powerpc/perf/core-fsl-emb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/perf') diff --git a/arch/powerpc/perf/core-fsl-emb.c b/arch/powerpc/perf/core-fsl-emb.c index e9fe904b6538..5d747b4cb8ee 100644 --- a/arch/powerpc/perf/core-fsl-emb.c +++ b/arch/powerpc/perf/core-fsl-emb.c @@ -330,9 +330,11 @@ static int fsl_emb_pmu_add(struct perf_event *event, int flags) } local64_set(&event->hw.prev_count, val); - if (!(flags & PERF_EF_START)) { + if (unlikely(!(flags & PERF_EF_START))) { event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE; val = 0; + } else { + event->hw.state &= ~(PERF_HES_STOPPED | PERF_HES_UPTODATE); } write_pmc(i, val); -- cgit v1.2.3