6.1-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Richter tmricht@linux.ibm.com
[ Upstream commit d3db4ac3c761def3d3a8e5ea6d05d1636c44c2ba ]
Rework the mapped buffer reference count in PMU pai_crypto to match the same technique as in PMU pai_ext. This simplifies the logic. Do not count the individual number of counter and sampling processes. Remember the type of access and the total number of references to the buffer.
Signed-off-by: Thomas Richter tmricht@linux.ibm.com Acked-by: Sumanth Korikkar sumanthk@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Stable-dep-of: e9f3af02f639 ("s390/pai: fix sampling event removal for PMU device driver") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/kernel/perf_pai_crypto.c | 42 ++++++++++++++---------------- 1 file changed, 20 insertions(+), 22 deletions(-)
diff --git a/arch/s390/kernel/perf_pai_crypto.c b/arch/s390/kernel/perf_pai_crypto.c index f61a652046cfb..68a6132937f3e 100644 --- a/arch/s390/kernel/perf_pai_crypto.c +++ b/arch/s390/kernel/perf_pai_crypto.c @@ -36,8 +36,8 @@ struct paicrypt_map { unsigned long *page; /* Page for CPU to store counters */ struct pai_userdata *save; /* Page to store no-zero counters */ unsigned int users; /* # of PAI crypto users */ - unsigned int sampler; /* # of PAI crypto samplers */ - unsigned int counter; /* # of PAI crypto counters */ + unsigned int refcnt; /* Reference count mapped buffers */ + enum paievt_mode mode; /* Type of event */ struct perf_event *event; /* Perf event for sampling */ };
@@ -56,15 +56,11 @@ static void paicrypt_event_destroy(struct perf_event *event) cpump->event = NULL; static_branch_dec(&pai_key); mutex_lock(&pai_reserve_mutex); - if (event->attr.sample_period) - cpump->sampler -= 1; - else - cpump->counter -= 1; - debug_sprintf_event(cfm_dbg, 5, "%s event %#llx cpu %d" - " sampler %d counter %d\n", __func__, - event->attr.config, event->cpu, cpump->sampler, - cpump->counter); - if (!cpump->counter && !cpump->sampler) { + debug_sprintf_event(cfm_dbg, 5, "%s event %#llx cpu %d users %d" + " mode %d refcnt %d\n", __func__, + event->attr.config, event->cpu, cpump->users, + cpump->mode, cpump->refcnt); + if (!--cpump->refcnt) { debug_sprintf_event(cfm_dbg, 4, "%s page %#lx save %p\n", __func__, (unsigned long)cpump->page, cpump->save); @@ -72,6 +68,7 @@ static void paicrypt_event_destroy(struct perf_event *event) cpump->page = NULL; kvfree(cpump->save); cpump->save = NULL; + cpump->mode = PAI_MODE_NONE; } mutex_unlock(&pai_reserve_mutex); } @@ -136,17 +133,14 @@ static u64 paicrypt_getall(struct perf_event *event) */ static int paicrypt_busy(struct perf_event_attr *a, struct paicrypt_map *cpump) { - unsigned int *use_ptr; int rc = 0;
mutex_lock(&pai_reserve_mutex); if (a->sample_period) { /* Sampling requested */ - use_ptr = &cpump->sampler; - if (cpump->counter || cpump->sampler) + if (cpump->mode != PAI_MODE_NONE) rc = -EBUSY; /* ... sampling/counting active */ } else { /* Counting requested */ - use_ptr = &cpump->counter; - if (cpump->sampler) + if (cpump->mode == PAI_MODE_SAMPLING) rc = -EBUSY; /* ... and sampling active */ } if (rc) @@ -172,12 +166,16 @@ static int paicrypt_busy(struct perf_event_attr *a, struct paicrypt_map *cpump) rc = 0;
unlock: - /* If rc is non-zero, do not increment counter/sampler. */ - if (!rc) - *use_ptr += 1; - debug_sprintf_event(cfm_dbg, 5, "%s sample_period %#llx sampler %d" - " counter %d page %#lx save %p rc %d\n", __func__, - a->sample_period, cpump->sampler, cpump->counter, + /* If rc is non-zero, do not set mode and reference count */ + if (!rc) { + cpump->refcnt++; + cpump->mode = a->sample_period ? PAI_MODE_SAMPLING + : PAI_MODE_COUNTING; + } + debug_sprintf_event(cfm_dbg, 5, "%s sample_period %#llx users %d" + " mode %d refcnt %d page %#lx save %p rc %d\n", + __func__, a->sample_period, cpump->users, + cpump->mode, cpump->refcnt, (unsigned long)cpump->page, cpump->save, rc); mutex_unlock(&pai_reserve_mutex); return rc;