1 files changed, 33 insertions, 55 deletions

diff --git a/drivers/media/video/v4l2-event.c b/drivers/media/video/v4l2-event.c
index dc68f6085697..9e325dd3ce27 100644
--- a/drivers/media/video/v4l2-event.c
+++ b/drivers/media/video/v4l2-event.c
@@ -30,44 +30,11 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 
-static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
-
-int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n)
-{
-	unsigned long flags;
-
-	while (fh->nallocated < n) {
-		struct v4l2_kevent *kev;
-
-		kev = kzalloc(sizeof(*kev), GFP_KERNEL);
-		if (kev == NULL)
-			return -ENOMEM;
-
-		spin_lock_irqsave(&fh->vdev->fh_lock, flags);
-		list_add_tail(&kev->list, &fh->free);
-		fh->nallocated++;
-		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(v4l2_event_alloc);
-
-#define list_kfree(list, type, member)				\
-	while (!list_empty(list)) {				\
-		type *hi;					\
-		hi = list_first_entry(list, type, member);	\
-		list_del(&hi->member);				\
-		kfree(hi);					\
-	}
-
-void v4l2_event_free(struct v4l2_fh *fh)
+static unsigned sev_pos(const struct v4l2_subscribed_event *sev, unsigned idx)
 {
-	list_kfree(&fh->free, struct v4l2_kevent, list);
-	list_kfree(&fh->available, struct v4l2_kevent, list);
-	v4l2_event_unsubscribe_all(fh);
+	idx += sev->first;
+	return idx >= sev->elems ? idx - sev->elems : idx;
 }
-EXPORT_SYMBOL_GPL(v4l2_event_free);
 
 static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
 {
@@ -84,11 +51,13 @@ static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
 	WARN_ON(fh->navailable == 0);
 
 	kev = list_first_entry(&fh->available, struct v4l2_kevent, list);
-	list_move(&kev->list, &fh->free);
+	list_del(&kev->list);
 	fh->navailable--;
 
 	kev->event.pending = fh->navailable;
 	*event = kev->event;
+	kev->sev->first = sev_pos(kev->sev, 1);
+	kev->sev->in_use--;
 
 	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
 
@@ -154,17 +123,24 @@ static void __v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *e
 	fh->sequence++;
 
 	/* Do we have any free events? */
-	if (list_empty(&fh->free))
-		return;
+	if (sev->in_use == sev->elems) {
+		/* no, remove the oldest one */
+		kev = sev->events + sev_pos(sev, 0);
+		list_del(&kev->list);
+		sev->in_use--;
+		sev->first = sev_pos(sev, 1);
+		fh->navailable--;
+	}
 
 	/* Take one and fill it. */
-	kev = list_first_entry(&fh->free, struct v4l2_kevent, list);
+	kev = sev->events + sev_pos(sev, sev->in_use);
 	kev->event.type = ev->type;
 	kev->event.u = ev->u;
 	kev->event.id = ev->id;
 	kev->event.timestamp = *ts;
 	kev->event.sequence = fh->sequence;
-	list_move_tail(&kev->list, &fh->available);
+	sev->in_use++;
+	list_add_tail(&kev->list, &fh->available);
 
 	fh->navailable++;
 
@@ -209,38 +185,39 @@ int v4l2_event_pending(struct v4l2_fh *fh)
 EXPORT_SYMBOL_GPL(v4l2_event_pending);
 
 int v4l2_event_subscribe(struct v4l2_fh *fh,
-			 struct v4l2_event_subscription *sub)
+			 struct v4l2_event_subscription *sub, unsigned elems)
 {
 	struct v4l2_subscribed_event *sev, *found_ev;
 	struct v4l2_ctrl *ctrl = NULL;
 	unsigned long flags;
+	unsigned i;
 
+	if (elems < 1)
+		elems = 1;
 	if (sub->type == V4L2_EVENT_CTRL) {
 		ctrl = v4l2_ctrl_find(fh->ctrl_handler, sub->id);
 		if (ctrl == NULL)
 			return -EINVAL;
 	}
 
-	sev = kzalloc(sizeof(*sev), GFP_KERNEL);
+	sev = kzalloc(sizeof(*sev) + sizeof(struct v4l2_kevent) * elems, GFP_KERNEL);
 	if (!sev)
 		return -ENOMEM;
+	for (i = 0; i < elems; i++)
+		sev->events[i].sev = sev;
+	sev->type = sub->type;
+	sev->id = sub->id;
+	sev->flags = sub->flags;
+	sev->fh = fh;
+	sev->elems = elems;
 
 	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
-
 	found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
-	if (!found_ev) {
-		INIT_LIST_HEAD(&sev->list);
-		sev->type = sub->type;
-		sev->id = sub->id;
-		sev->fh = fh;
-		sev->flags = sub->flags;
-
+	if (!found_ev)
 		list_add(&sev->list, &fh->subscribed);
-	}
-
 	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
 
-	/* v4l2_ctrl_add_fh uses a mutex, so do this outside the spin lock */
+	/* v4l2_ctrl_add_event uses a mutex, so do this outside the spin lock */
 	if (found_ev)
 		kfree(sev);
 	else if (ctrl)
@@ -250,7 +227,7 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
 }
 EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
 
-static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
+void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
 {
 	struct v4l2_event_subscription sub;
 	struct v4l2_subscribed_event *sev;
@@ -271,6 +248,7 @@ static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
 			v4l2_event_unsubscribe(fh, &sub);
 	} while (sev);
 }
+EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe_all);
 
 int v4l2_event_unsubscribe(struct v4l2_fh *fh,
 			   struct v4l2_event_subscription *sub)