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Commit 01552f76 authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Add initial perf event conflict resolution and checks. 



Cribbed from powerpc code, as usual. :-)

Currently it is only used to validate that all counters
have the same user/kernel/hv attributes.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7eebda60

arch/sparc/kernel/perf_event.c

+77 −5
Original line number Diff line number Diff line
@@ -713,12 +713,66 @@ static void hw_perf_event_destroy(struct perf_event *event) 
	perf_event_release_pmc();

}



static int check_excludes(struct perf_event **evts, int n_prev, int n_new)

{

	int eu = 0, ek = 0, eh = 0;

	struct perf_event *event;

	int i, n, first;



	n = n_prev + n_new;

	if (n <= 1)

		return 0;



	first = 1;

	for (i = 0; i < n; i++) {

		event = evts[i];

		if (first) {

			eu = event->attr.exclude_user;

			ek = event->attr.exclude_kernel;

			eh = event->attr.exclude_hv;

			first = 0;

		} else if (event->attr.exclude_user != eu ||

			   event->attr.exclude_kernel != ek ||

			   event->attr.exclude_hv != eh) {

			return -EAGAIN;

		}

	}



	return 0;

}



static int collect_events(struct perf_event *group, int max_count,

			  struct perf_event *evts[], u64 *events)

{

	struct perf_event *event;

	int n = 0;



	if (!is_software_event(group)) {

		if (n >= max_count)

			return -1;

		evts[n] = group;

		events[n++] = group->hw.config;

	}

	list_for_each_entry(event, &group->sibling_list, group_entry) {

		if (!is_software_event(event) &&

		    event->state != PERF_EVENT_STATE_OFF) {

			if (n >= max_count)

				return -1;

			evts[n] = event;

			events[n++] = event->hw.config;

		}

	}

	return n;

}



static int __hw_perf_event_init(struct perf_event *event)

{

	struct perf_event_attr *attr = &event->attr;

	struct perf_event *evts[MAX_HWEVENTS];

	struct hw_perf_event *hwc = &event->hw;

	const struct perf_event_map *pmap;

	u64 enc;

	u64 enc, events[MAX_HWEVENTS];

	int n;



	if (atomic_read(&nmi_active) < 0)

		return -ENODEV;
@@ -734,9 +788,6 @@ static int __hw_perf_event_init(struct perf_event *event) 
	} else

		return -EOPNOTSUPP;



	perf_event_grab_pmc();

	event->destroy = hw_perf_event_destroy;



	/* We save the enable bits in the config_base.  So to

	 * turn off sampling just write 'config', and to enable

	 * things write 'config | config_base'.
@@ -749,13 +800,34 @@ static int __hw_perf_event_init(struct perf_event *event) 
	if (!attr->exclude_hv)

		hwc->config_base |= sparc_pmu->hv_bit;



	enc = pmap->encoding;



	n = 0;

	if (event->group_leader != event) {

		n = collect_events(event->group_leader,

				   perf_max_events - 1,

				   evts, events);

		if (n < 0)

			return -EINVAL;

	}

	events[n] = enc;

	evts[n] = event;



	if (check_excludes(evts, n, 1))

		return -EINVAL;



	/* Try to do all error checking before this point, as unwinding

	 * state after grabbing the PMC is difficult.

	 */

	perf_event_grab_pmc();

	event->destroy = hw_perf_event_destroy;



	if (!hwc->sample_period) {

		hwc->sample_period = MAX_PERIOD;

		hwc->last_period = hwc->sample_period;

		atomic64_set(&hwc->period_left, hwc->sample_period);

	}



	enc = pmap->encoding;

	if (pmap->pic_mask & PIC_UPPER) {

		hwc->idx = PIC_UPPER_INDEX;

		enc <<= sparc_pmu->upper_shift;