drm: Create drm_send_event helpers

Use them in the core vblank code and exynos/vmwgfx drivers.

Note that the difference between wake_up_all and _interruptible in
vmwgfx doesn't matter since the only waiter is the core code in
drm_fops.c. And that is interruptible.

v2: Adjust existing kerneldoc too.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com> (v1)
Acked-by: Daniel Stone <daniels@collabora.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Inki Dae <inki.dae@samsung.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452548477-15905-6-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[danvet: Squash in compile fixup, spotted by 0-day.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_fops.c

@@ -687,7 +687,9 @@ EXPORT_SYMBOL(drm_poll);
  * This function prepares the passed in event for eventual delivery. If the event
  * doesn't get delivered (because the IOCTL fails later on, before queuing up
  * anything) then the even must be cancelled and freed using
- * drm_event_cancel_free().
+ * drm_event_cancel_free(). Successfully initialized events should be sent out
+ * using drm_send_event() or drm_send_event_locked() to signal completion of the
+ * asynchronous event to userspace.
  *
  * If callers embedded @p into a larger structure it must be allocated with
  * kmalloc and @p must be the first member element.
@@ -743,3 +745,41 @@ void drm_event_cancel_free(struct drm_device *dev,
 	p->destroy(p);
 }
 EXPORT_SYMBOL(drm_event_cancel_free);
+
+/**
+ * drm_send_event_locked - send DRM event to file descriptor
+ * @dev: DRM device
+ * @e: DRM event to deliver
+ *
+ * This function sends the event @e, initialized with drm_event_reserve_init(),
+ * to its associated userspace DRM file. Callers must already hold
+ * dev->event_lock, see drm_send_event() for the unlocked version.
+ */
+void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
+{
+	assert_spin_locked(&dev->event_lock);
+
+	list_add_tail(&e->link,
+		      &e->file_priv->event_list);
+	wake_up_interruptible(&e->file_priv->event_wait);
+}
+EXPORT_SYMBOL(drm_send_event_locked);
+
+/**
+ * drm_send_event - send DRM event to file descriptor
+ * @dev: DRM device
+ * @e: DRM event to deliver
+ *
+ * This function sends the event @e, initialized with drm_event_reserve_init(),
+ * to its associated userspace DRM file. This function acquires dev->event_lock,
+ * see drm_send_event_locked() for callers which already hold this lock.
+ */
+void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&dev->event_lock, irqflags);
+	drm_send_event_locked(dev, e);
+	spin_unlock_irqrestore(&dev->event_lock, irqflags);
+}
+EXPORT_SYMBOL(drm_send_event);

drivers/gpu/drm/drm_irq.c

@@ -983,15 +983,12 @@ static void send_vblank_event(struct drm_device *dev,
 		struct drm_pending_vblank_event *e,
 		unsigned long seq, struct timeval *now)
 {
-	assert_spin_locked(&dev->event_lock);
-
 	e->event.sequence = seq;
 	e->event.tv_sec = now->tv_sec;
 	e->event.tv_usec = now->tv_usec;
 
-	list_add_tail(&e->base.link,
+	drm_send_event_locked(dev, &e->base);
-		      &e->base.file_priv->event_list);
+
-	wake_up_interruptible(&e->base.file_priv->event_wait);
 	trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
 					 e->event.sequence);
 }

drivers/gpu/drm/exynos/exynos_drm_g2d.c

@@ -880,7 +880,6 @@ static void g2d_finish_event(struct g2d_data *g2d, u32 cmdlist_no)
 	struct g2d_runqueue_node *runqueue_node = g2d->runqueue_node;
 	struct drm_exynos_pending_g2d_event *e;
 	struct timeval now;
-	unsigned long flags;
 
 	if (list_empty(&runqueue_node->event_list))
 		return;
@@ -893,10 +892,7 @@ static void g2d_finish_event(struct g2d_data *g2d, u32 cmdlist_no)
 	e->event.tv_usec = now.tv_usec;
 	e->event.cmdlist_no = cmdlist_no;
 
-	spin_lock_irqsave(&drm_dev->event_lock, flags);
+	drm_send_event(drm_dev, &e->base);
-	list_move_tail(&e->base.link, &e->base.file_priv->event_list);
-	wake_up_interruptible(&e->base.file_priv->event_wait);
-	spin_unlock_irqrestore(&drm_dev->event_lock, flags);
 }
 
 static irqreturn_t g2d_irq_handler(int irq, void *dev_id)

drivers/gpu/drm/exynos/exynos_drm_ipp.c

@@ -1407,7 +1407,6 @@ static int ipp_send_event(struct exynos_drm_ippdrv *ippdrv,
 	struct drm_exynos_ipp_send_event *e;
 	struct list_head *head;
 	struct timeval now;
-	unsigned long flags;
 	u32 tbuf_id[EXYNOS_DRM_OPS_MAX] = {0, };
 	int ret, i;
 
@@ -1520,10 +1519,7 @@ static int ipp_send_event(struct exynos_drm_ippdrv *ippdrv,
 	for_each_ipp_ops(i)
 		e->event.buf_id[i] = tbuf_id[i];
 
-	spin_lock_irqsave(&drm_dev->event_lock, flags);
+	drm_send_event(drm_dev, &e->base);
-	list_move_tail(&e->base.link, &e->base.file_priv->event_list);
-	wake_up_interruptible(&e->base.file_priv->event_wait);
-	spin_unlock_irqrestore(&drm_dev->event_lock, flags);
 	mutex_unlock(&c_node->event_lock);
 
 	DRM_DEBUG_KMS("done cmd[%d]prop_id[%d]buf_id[%d]\n",

drivers/gpu/drm/vmwgfx/vmwgfx_fence.c

@@ -880,9 +880,8 @@ static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
 	}
 
 	list_del_init(&eaction->fpriv_head);
-	list_add_tail(&eaction->event->link, &file_priv->event_list);
 	eaction->event = NULL;
-	wake_up_all(&file_priv->event_wait);
+	drm_send_event_locked(dev, eaction->event);
 	spin_unlock_irqrestore(&dev->event_lock, irq_flags);
 }
 

include/drm/drmP.h

@@ -932,6 +932,8 @@ int drm_event_reserve_init(struct drm_device *dev,
 			   struct drm_event *e);
 void drm_event_cancel_free(struct drm_device *dev,
 			   struct drm_pending_event *p);
+void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e);
+void drm_send_event(struct drm_device *dev, struct drm_pending_event *e);
 
 /* Misc. IOCTL support (drm_ioctl.c) */
 int drm_noop(struct drm_device *dev, void *data,