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s390/pai_crypto: Enable per-task counting event

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The PMU for PAI crypto counters enforces the following restriction:

     - No per-task context for PAI crypto counters events.

This restriction is removed. One or more per-task/system-wide counting
events can now be active at the same time while at most one system
wide sampling event is active.

Example for per-task context of a PAI crypto counter event:
   # perf stat -e pai_crypto/KM_AES_128/ -- true

Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Thomas Richter 2024-02-29 15:45:04 +01:00 committed by Alexander Gordeev
parent fb412c6241
commit 92ea686840
2 changed files with 68 additions and 14 deletions
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1
arch/s390/include/asm/pai.h
View File

@ -82,4 +82,5 @@ enum paievt_mode {
};
#define PAI_SAVE_AREA(x) ((x)->hw.event_base)
#define PAI_CPU_MASK(x) ((x)->hw.addr_filters)
#endif

81
arch/s390/kernel/perf_pai_crypto.c
View File

@ -84,13 +84,11 @@ static DEFINE_MUTEX(pai_reserve_mutex);
/* Adjust usage counters and remove allocated memory when all users are
* gone.
*/
static void paicrypt_event_destroy(struct perf_event *event)
static void paicrypt_event_destroy_cpu(struct perf_event *event, int cpu)
{
struct paicrypt_mapptr *mp = per_cpu_ptr(paicrypt_root.mapptr,
event->cpu);
struct paicrypt_mapptr *mp = per_cpu_ptr(paicrypt_root.mapptr, cpu);
struct paicrypt_map *cpump = mp->mapptr;
static_branch_dec(&pai_key);
mutex_lock(&pai_reserve_mutex);
debug_sprintf_event(cfm_dbg, 5, "%s event %#llx cpu %d users %d"
" mode %d refcnt %u\n", __func__,
@ -99,7 +97,6 @@ static void paicrypt_event_destroy(struct perf_event *event)
refcount_read(&cpump->refcnt));
if (event->attr.sample_period)
cpump->mode &= ~PAI_MODE_SAMPLING;
free_page(PAI_SAVE_AREA(event));
if (refcount_dec_and_test(&cpump->refcnt)) {
debug_sprintf_event(cfm_dbg, 4, "%s page %#lx save %p\n",
__func__, (unsigned long)cpump->page,
@ -113,6 +110,23 @@ static void paicrypt_event_destroy(struct perf_event *event)
mutex_unlock(&pai_reserve_mutex);
}
static void paicrypt_event_destroy(struct perf_event *event)
{
int cpu;
static_branch_dec(&pai_key);
free_page(PAI_SAVE_AREA(event));
if (event->cpu == -1) {
struct cpumask *mask = PAI_CPU_MASK(event);
for_each_cpu(cpu, mask)
paicrypt_event_destroy_cpu(event, cpu);
kfree(mask);
} else {
paicrypt_event_destroy_cpu(event, event->cpu);
}
}
static u64 paicrypt_getctr(unsigned long *page, int nr, bool kernel)
{
if (kernel)
@ -170,7 +184,7 @@ static u64 paicrypt_getall(struct perf_event *event)
*
* Allocate the memory for the event.
*/
static struct paicrypt_map *paicrypt_busy(struct perf_event *event)
static struct paicrypt_map *paicrypt_busy(struct perf_event *event, int cpu)
{
struct perf_event_attr *a = &event->attr;
struct paicrypt_map *cpump = NULL;
@ -185,7 +199,7 @@ static struct paicrypt_map *paicrypt_busy(struct perf_event *event)
goto unlock;
/* Allocate node for this event */
mp = per_cpu_ptr(paicrypt_root.mapptr, event->cpu);
mp = per_cpu_ptr(paicrypt_root.mapptr, cpu);
cpump = mp->mapptr;
if (!cpump) { /* Paicrypt_map allocated? */
cpump = kzalloc(sizeof(*cpump), GFP_KERNEL);
@ -253,6 +267,40 @@ unlock:
return rc ? ERR_PTR(rc) : cpump;
}
static int paicrypt_event_init_all(struct perf_event *event)
{
struct paicrypt_map *cpump;
struct cpumask *maskptr;
int cpu, rc = -ENOMEM;
maskptr = kzalloc(sizeof(*maskptr), GFP_KERNEL);
if (!maskptr)
goto out;
for_each_online_cpu(cpu) {
cpump = paicrypt_busy(event, cpu);
if (IS_ERR(cpump)) {
for_each_cpu(cpu, maskptr)
paicrypt_event_destroy_cpu(event, cpu);
kfree(maskptr);
rc = PTR_ERR(cpump);
goto out;
}
cpumask_set_cpu(cpu, maskptr);
}
/*
* On error all cpumask are freed and all events have been destroyed.
* Save of which CPUs data structures have been allocated for.
* Release them in paicrypt_event_destroy call back function
* for this event.
*/
PAI_CPU_MASK(event) = maskptr;
rc = 0;
out:
return rc;
}
/* Might be called on different CPU than the one the event is intended for. */
static int paicrypt_event_init(struct perf_event *event)
{
@ -267,8 +315,9 @@ static int paicrypt_event_init(struct perf_event *event)
if (a->config < PAI_CRYPTO_BASE ||
a->config > PAI_CRYPTO_BASE + paicrypt_cnt)
return -EINVAL;
/* Allow only CPU wide operation, no process context for now. */
if ((event->attach_state & PERF_ATTACH_TASK) || event->cpu == -1)
/* Allow only CPU wide operation for sampling */
if (a->sample_period &&
((event->attach_state & PERF_ATTACH_TASK) || event->cpu == -1))
return -ENOENT;
/* Allow only CRYPTO_ALL for sampling. */
if (a->sample_period && a->config != PAI_CRYPTO_BASE)
@ -282,13 +331,17 @@ static int paicrypt_event_init(struct perf_event *event)
}
}
cpump = paicrypt_busy(event);
if (IS_ERR(cpump)) {
if (event->cpu >= 0) {
cpump = paicrypt_busy(event, event->cpu);
if (IS_ERR(cpump))
rc = PTR_ERR(cpump);
} else {
rc = paicrypt_event_init_all(event);
}
if (rc) {
free_page(PAI_SAVE_AREA(event));
rc = PTR_ERR(cpump);
goto out;
}
event->destroy = paicrypt_event_destroy;
if (a->sample_period) {
@ -526,7 +579,7 @@ static const struct attribute_group *paicrypt_attr_groups[] = {
/* Performance monitoring unit for mapped counters */
static struct pmu paicrypt = {
.task_ctx_nr = perf_invalid_context,
.task_ctx_nr = perf_hw_context,
.event_init = paicrypt_event_init,
.add = paicrypt_add,
.del = paicrypt_del,