Commit d3db4ac3 authored by Thomas Richter's avatar Thomas Richter Committed by Vasily Gorbik
Browse files

s390/pai: rework pai_crypto mapped buffer reference count 



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: default avatarThomas Richter <tmricht@linux.ibm.com>
Acked-by: default avatarSumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 4c787963

arch/s390/kernel/perf_pai_crypto.c

+20 −22
Original line number Diff line number Diff line
@@ -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;