From: Thomas Richter tmricht@linux.ibm.com
[ Upstream commit 6a82e23f45fe0aa821e7a935e39d0acb20c275c0 ]
Linux-next commit titled "perf/core: Optimize perf_init_event()" changed the semantics of PMU device driver registration. It was done to speed up the lookup/handling of PMU device driver specific events. It also enforces that only one PMU device driver will be registered of type PERF_EVENT_RAW.
This change added these line in function perf_pmu_register():
... + ret = idr_alloc(&pmu_idr, pmu, max, 0, GFP_KERNEL); + if (ret < 0) goto free_pdc; + + WARN_ON(type >= 0 && ret != type);
The warn_on generates a message. We have 3 PMU device drivers, each registered as type PERF_TYPE_RAW. The cf_diag device driver (arch/s390/kernel/perf_cpumf_cf_diag.c) always hits the WARN_ON because it is the second PMU device driver (after sampling device driver arch/s390/kernel/perf_cpumf_sf.c) which is registered as type 4 (PERF_TYPE_RAW). So when the sampling device driver is registered, ret has value 4. When cf_diag device driver is registered with type 4, ret has value of 5 and WARN_ON fires.
Adjust the PMU device drivers for s390 to support the new semantics required by perf_pmu_register().
Signed-off-by: Thomas Richter tmricht@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/kernel/perf_cpum_cf.c | 21 ++++++++++----------- arch/s390/kernel/perf_cpum_cf_diag.c | 10 +++++----- 2 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c index 48d48b6187c0..0eb1d1cc53a8 100644 --- a/arch/s390/kernel/perf_cpum_cf.c +++ b/arch/s390/kernel/perf_cpum_cf.c @@ -199,7 +199,7 @@ static const int cpumf_generic_events_user[] = { [PERF_COUNT_HW_BUS_CYCLES] = -1, };
-static int __hw_perf_event_init(struct perf_event *event) +static int __hw_perf_event_init(struct perf_event *event, unsigned int type) { struct perf_event_attr *attr = &event->attr; struct hw_perf_event *hwc = &event->hw; @@ -207,7 +207,7 @@ static int __hw_perf_event_init(struct perf_event *event) int err = 0; u64 ev;
- switch (attr->type) { + switch (type) { case PERF_TYPE_RAW: /* Raw events are used to access counters directly, * hence do not permit excludes */ @@ -294,17 +294,16 @@ static int __hw_perf_event_init(struct perf_event *event)
static int cpumf_pmu_event_init(struct perf_event *event) { + unsigned int type = event->attr.type; int err;
- switch (event->attr.type) { - case PERF_TYPE_HARDWARE: - case PERF_TYPE_HW_CACHE: - case PERF_TYPE_RAW: - err = __hw_perf_event_init(event); - break; - default: + if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_RAW) + err = __hw_perf_event_init(event, type); + else if (event->pmu->type == type) + /* Registered as unknown PMU */ + err = __hw_perf_event_init(event, PERF_TYPE_RAW); + else return -ENOENT; - }
if (unlikely(err) && event->destroy) event->destroy(event); @@ -553,7 +552,7 @@ static int __init cpumf_pmu_init(void) return -ENODEV;
cpumf_pmu.attr_groups = cpumf_cf_event_group(); - rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", PERF_TYPE_RAW); + rc = perf_pmu_register(&cpumf_pmu, "cpum_cf", -1); if (rc) pr_err("Registering the cpum_cf PMU failed with rc=%i\n", rc); return rc; diff --git a/arch/s390/kernel/perf_cpum_cf_diag.c b/arch/s390/kernel/perf_cpum_cf_diag.c index 2654e348801a..e949ab832ed7 100644 --- a/arch/s390/kernel/perf_cpum_cf_diag.c +++ b/arch/s390/kernel/perf_cpum_cf_diag.c @@ -243,13 +243,13 @@ static int cf_diag_event_init(struct perf_event *event) int err = -ENOENT;
debug_sprintf_event(cf_diag_dbg, 5, - "%s event %p cpu %d config %#llx " + "%s event %p cpu %d config %#llx type:%u " "sample_type %#llx cf_diag_events %d\n", __func__, - event, event->cpu, attr->config, attr->sample_type, - atomic_read(&cf_diag_events)); + event, event->cpu, attr->config, event->pmu->type, + attr->sample_type, atomic_read(&cf_diag_events));
if (event->attr.config != PERF_EVENT_CPUM_CF_DIAG || - event->attr.type != PERF_TYPE_RAW) + event->attr.type != event->pmu->type) goto out;
/* Raw events are used to access counters directly, @@ -693,7 +693,7 @@ static int __init cf_diag_init(void) } debug_register_view(cf_diag_dbg, &debug_sprintf_view);
- rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", PERF_TYPE_RAW); + rc = perf_pmu_register(&cf_diag, "cpum_cf_diag", -1); if (rc) { debug_unregister_view(cf_diag_dbg, &debug_sprintf_view); debug_unregister(cf_diag_dbg);