Commit 74466e87 authored by Thomas Richter's avatar Thomas Richter Committed by Heiko Carstens
Browse files

s390/pai_crypto: Unify sample push logic and update context handling 



Unify naming and logic for PAI PMU drivers to support both PMUs
pai_crypto and pai_ext.

Rename paicrypt_push_sample() to pai_push_sample() to reflect
its common usage.  Add detailed comments about invocation context
and scheduler callbacks.  Use struct pai_pmu to determine area_size
instead of PAGE_SIZE for counter backup.
Remove obsolete variable paicrypt_cnt.

Signed-off-by: default avatarThomas Richter <tmricht@linux.ibm.com>
Reviewed-by: default avatarJan Polensky <japo@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 0f1c0d75

arch/s390/kernel/perf_pai_crypto.c

+20 −7
Original line number Diff line number Diff line
@@ -20,8 +20,6 @@ 
#include <asm/debug.h>



static debug_info_t *paidbg;

static unsigned int paicrypt_cnt;	/* Size of the mapped counter sets */

					/* extracted with QPACI instruction */



DEFINE_STATIC_KEY_FALSE(pai_key);
@@ -486,9 +484,25 @@ static size_t paicrypt_copy(struct pai_userdata *userdata, unsigned long *page, 
	return outidx * sizeof(*userdata);

}



static int paicrypt_push_sample(size_t rawsize, struct pai_map *cpump,

/* Write sample when one or more counters values are nonzero.

 *

 * Note: The function paicrypt_sched_task() and pai_push_sample() are not

 * invoked after function paicrypt_del() has been called because of function

 * perf_sched_cb_dec(). Both functions are only

 * called when sampling is active. Function perf_sched_cb_inc()

 * has been invoked to install function paicrypt_sched_task() as call back

 * to run at context switch time.

 *

 * This causes function perf_event_context_sched_out() and

 * perf_event_context_sched_in() to check whether the PMU has installed an

 * sched_task() callback. That callback is not active after paicrypt_del()

 * returns and has deleted the event on that CPU.

 */

static int pai_push_sample(size_t rawsize, struct pai_map *cpump,

			   struct perf_event *event)

{

	int idx = PAI_PMU_IDX(event);

	struct pai_pmu *pp = &pai_pmu[idx];

	struct perf_sample_data data;

	struct perf_raw_record raw;

	struct pt_regs regs;
@@ -520,7 +534,7 @@ static int paicrypt_push_sample(size_t rawsize, struct pai_map *cpump, 
	overflow = perf_event_overflow(event, &data, &regs);

	perf_event_update_userpage(event);

	/* Save crypto counter lowcore page after reading event data. */

	memcpy((void *)PAI_SAVE_AREA(event), cpump->area, PAGE_SIZE);

	memcpy((void *)PAI_SAVE_AREA(event), cpump->area, pp->area_size);

	return overflow;

}
@@ -538,7 +552,7 @@ static void pai_have_sample(struct perf_event *event, struct pai_map *cpump) 
				event->attr.exclude_user,

				event->attr.exclude_kernel);

	if (rawsize)			/* No incremented counters */

		paicrypt_push_sample(rawsize, cpump, event);

		pai_push_sample(rawsize, cpump, event);

}



/* Check if there is data to be saved on schedule out of a task. */
@@ -920,7 +934,6 @@ static int __init paipmu_setup(void) 
		switch (i) {

		case PAI_PMU_CRYPTO:

			p->num_avail = ib.num_cc;

			paicrypt_cnt = ib.num_cc;

			if (p->num_avail >= PAI_CRYPTO_MAXCTR) {

				pr_err("Too many PMU %s counters %d\n",

				       p->pmuname, p->num_avail);