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s390/pai: rework pai_crypto mapped buffer reference count

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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>
This commit is contained in:
Thomas Richter 2022-10-20 11:38:05 +02:00 committed by Vasily Gorbik
parent 4c78796301
commit d3db4ac3c7
1 changed files with 20 additions and 22 deletions
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42
arch/s390/kernel/perf_pai_crypto.c
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@ -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;