[PATCH V2 02/23] drm/etnaviv: make it possible to allocate multiple events

[Christian Gmeiner]

This makes it possible to allocate multiple events under the event
spinlock. This change is needed to support 'sync'-points.

Signed-off-by: Christian Gmeiner <christian.gmeiner at gmail.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index fa9c7bd98e9c..ab108b0ed573 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1137,10 +1137,12 @@ int etnaviv_gpu_fence_sync_obj(struct etnaviv_gem_object *etnaviv_obj,
  * event management:
  */
 
-static unsigned int event_alloc(struct etnaviv_gpu *gpu)
+static int event_alloc(struct etnaviv_gpu *gpu, unsigned nr_events,
+	unsigned int *events)
 {
 	unsigned long ret, flags;
-	unsigned int event;
+	unsigned used, i;
+	int err = 0;
 
 	ret = wait_for_completion_timeout(&gpu->event_free,
 					  msecs_to_jiffies(10 * 10000));
@@ -1149,16 +1151,24 @@ static unsigned int event_alloc(struct etnaviv_gpu *gpu)
 
 	spin_lock_irqsave(&gpu->event_spinlock, flags);
 
-	/* find first free event */
-	event = find_first_zero_bit(gpu->event_bitmap, ETNA_NR_EVENTS);
-	if (event < ETNA_NR_EVENTS)
+	/* are there enough free events? */
+	used = bitmap_weight(gpu->event_bitmap, ETNA_NR_EVENTS);
+	if (used + nr_events > ETNA_NR_EVENTS) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	for (i = 0; i < nr_events; i++) {
+		int event = find_first_zero_bit(gpu->event_bitmap, ETNA_NR_EVENTS);
+
+		events[i] = event;
 		set_bit(event, gpu->event_bitmap);
-	else
-		event = ~0U;
+	}
 
+out:
 	spin_unlock_irqrestore(&gpu->event_spinlock, flags);
 
-	return event;
+	return err;
 }
 
 static void event_free(struct etnaviv_gpu *gpu, unsigned int event)
@@ -1327,10 +1337,9 @@ int etnaviv_gpu_submit(struct etnaviv_gpu *gpu,
 	 *
 	 */
 
-	event = event_alloc(gpu);
-	if (unlikely(event == ~0U)) {
+	ret = event_alloc(gpu, 1, &event);
+	if (!ret) {
 		DRM_ERROR("no free event\n");
-		ret = -EBUSY;
 		goto out_pm_put;
 	}
 
-- 
2.13.3