From b58064da046243f0c988afd939997e9317dc6d48 Mon Sep 17 00:00:00 2001 From: Madhavan Srinivasan Date: Sun, 4 Mar 2018 17:26:26 +0530 Subject: [PATCH] powerpc/perf: Infrastructure to support addition of blacklisted events Introduce code to support addition of blacklisted events for a processor version. Blacklisted events are events that are known to not count correctly on that CPU revision, and so should be prevented from being counted so as to avoid user confusion. A 'pointer' and 'int' variable to hold the number of events are added to 'struct power_pmu', along with a generic function to loop through the list to validate the given event. Generic function 'is_event_blacklisted' is called in power_pmu_event_init() to detect and reject early. Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/perf_event_server.h | 2 ++ arch/powerpc/perf/core-book3s.c | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h index 723bf48..67a8a95 100644 --- a/arch/powerpc/include/asm/perf_event_server.h +++ b/arch/powerpc/include/asm/perf_event_server.h @@ -53,6 +53,8 @@ struct power_pmu { [PERF_COUNT_HW_CACHE_OP_MAX] [PERF_COUNT_HW_CACHE_RESULT_MAX]; + int n_blacklist_ev; + int *blacklist_ev; /* BHRB entries in the PMU */ int bhrb_nr; }; diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index a00b364..e032aef 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1839,6 +1839,18 @@ static int hw_perf_cache_event(u64 config, u64 *eventp) return 0; } +static bool is_event_blacklisted(u64 ev) +{ + int i; + + for (i=0; i < ppmu->n_blacklist_ev; i++) { + if (ppmu->blacklist_ev[i] == ev) + return true; + } + + return false; +} + static int power_pmu_event_init(struct perf_event *event) { u64 ev; @@ -1864,15 +1876,24 @@ static int power_pmu_event_init(struct perf_event *event) ev = event->attr.config; if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0) return -EOPNOTSUPP; + + if (ppmu->blacklist_ev && is_event_blacklisted(ev)) + return -EINVAL; ev = ppmu->generic_events[ev]; break; case PERF_TYPE_HW_CACHE: err = hw_perf_cache_event(event->attr.config, &ev); if (err) return err; + + if (ppmu->blacklist_ev && is_event_blacklisted(ev)) + return -EINVAL; break; case PERF_TYPE_RAW: ev = event->attr.config; + + if (ppmu->blacklist_ev && is_event_blacklisted(ev)) + return -EINVAL; break; default: return -ENOENT; -- 2.7.4