drm: Reorganize drm_pending_event to support future event types [v2]

Place drm_event_vblank in a new union that includes that and a bare
drm_event structure. This will allow new members of that union to be
added in the future without changing code related to the existing vbl
event type.

Assignments to the crtc_id field are now done when the event is
allocated, rather than when delievered. This way, delivery doesn't
need to have the crtc ID available.

v2:
 * Remove 'dev' argument from create_vblank_event

	It wasn't being used anyways, and if we need it in the future,
	we can always get it from crtc->dev.

 * Check for MODESETTING before looking for crtc in queue_vblank_event

	UMS drivers will oops if we try to get a crtc, so make sure
	we're modesetting before we try to find a crtc_id to fill into
	the event.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit dc695b85fde88eca3ef3b03fcd82f15b6bc6e462)

drivers/gpu/drm/drm_atomic.c

@@ -1812,7 +1812,7 @@ int drm_atomic_debugfs_init(struct drm_minor *minor)
  */
 
 static struct drm_pending_vblank_event *create_vblank_event(
-		struct drm_device *dev, uint64_t user_data)
+		struct drm_crtc *crtc, uint64_t user_data)
 {
 	struct drm_pending_vblank_event *e = NULL;
 
@@ -1822,7 +1822,8 @@ static struct drm_pending_vblank_event *create_vblank_event(
 
 	e->event.base.type = DRM_EVENT_FLIP_COMPLETE;
 	e->event.base.length = sizeof(e->event);
-	e->event.user_data = user_data;
+	e->event.vbl.crtc_id = crtc->base.id;
+	e->event.vbl.user_data = user_data;
 
 	return e;
 }
@@ -2076,7 +2077,7 @@ static int prepare_crtc_signaling(struct drm_device *dev,
 		if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) {
 			struct drm_pending_vblank_event *e;
 
-			e = create_vblank_event(dev, arg->user_data);
+			e = create_vblank_event(crtc, arg->user_data);
 			if (!e)
 				return -ENOMEM;
 

drivers/gpu/drm/drm_plane.c

@@ -1025,7 +1025,7 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
 		}
 		e->event.base.type = DRM_EVENT_FLIP_COMPLETE;
 		e->event.base.length = sizeof(e->event);
-		e->event.user_data = page_flip->user_data;
+		e->event.vbl.user_data = page_flip->user_data;
 		ret = drm_event_reserve_init(dev, file_priv, &e->base, &e->event.base);
 		if (ret) {
 			kfree(e);

drivers/gpu/drm/drm_vblank.c

@@ -804,20 +804,23 @@ static void send_vblank_event(struct drm_device *dev,
 		struct drm_pending_vblank_event *e,
 		u64 seq, ktime_t now)
 {
-	struct timespec64 tv = ktime_to_timespec64(now);
-
-	e->event.sequence = seq;
-	/*
-	 * e->event is a user space structure, with hardcoded unsigned
-	 * 32-bit seconds/microseconds. This is safe as we always use
-	 * monotonic timestamps since linux-4.15
-	 */
-	e->event.tv_sec = tv.tv_sec;
-	e->event.tv_usec = tv.tv_nsec / 1000;
-
-	trace_drm_vblank_event_delivered(e->base.file_priv, e->pipe,
-					 e->event.sequence);
+	struct timespec64 tv;
 
+	switch (e->event.base.type) {
+	case DRM_EVENT_VBLANK:
+	case DRM_EVENT_FLIP_COMPLETE:
+		tv = ktime_to_timespec64(now);
+		e->event.vbl.sequence = seq;
+		/*
+		 * e->event is a user space structure, with hardcoded unsigned
+		 * 32-bit seconds/microseconds. This is safe as we always use
+		 * monotonic timestamps since linux-4.15
+		 */
+		e->event.vbl.tv_sec = tv.tv_sec;
+		e->event.vbl.tv_usec = tv.tv_nsec / 1000;
+		break;
+	}
+	trace_drm_vblank_event_delivered(e->base.file_priv, e->pipe, seq);
 	drm_send_event_locked(dev, &e->base);
 }
 
@@ -869,7 +872,6 @@ void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
 
 	e->pipe = pipe;
 	e->sequence = drm_crtc_accurate_vblank_count(crtc) + 1;
-	e->event.crtc_id = crtc->base.id;
 	list_add_tail(&e->base.link, &dev->vblank_event_list);
 }
 EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
@@ -901,7 +903,6 @@ void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
 		now = ktime_get();
 	}
 	e->pipe = pipe;
-	e->event.crtc_id = crtc->base.id;
 	send_vblank_event(dev, e, seq, now);
 }
 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
@@ -1336,8 +1337,14 @@ static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
 
 	e->pipe = pipe;
 	e->event.base.type = DRM_EVENT_VBLANK;
-	e->event.base.length = sizeof(e->event);
-	e->event.user_data = vblwait->request.signal;
+	e->event.base.length = sizeof(e->event.vbl);
+	e->event.vbl.user_data = vblwait->request.signal;
+	e->event.vbl.crtc_id = 0;
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+		if (crtc)
+			e->event.vbl.crtc_id = crtc->base.id;
+	}
 
 	spin_lock_irqsave(&dev->event_lock, flags);
 

drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c

@@ -360,8 +360,8 @@ static int vmw_sou_crtc_page_flip(struct drm_crtc *crtc,
 
 		ret = vmw_event_fence_action_queue(file_priv, fence,
 						   &event->base,
-						   &event->event.tv_sec,
-						   &event->event.tv_usec,
+						   &event->event.vbl.tv_sec,
+						   &event->event.vbl.tv_usec,
 						   true);
 	}
 

drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c

@@ -549,8 +549,8 @@ static int vmw_stdu_crtc_page_flip(struct drm_crtc *crtc,
 
 		ret = vmw_event_fence_action_queue(file_priv, fence,
 						   &event->base,
-						   &event->event.tv_sec,
-						   &event->event.tv_usec,
+						   &event->event.vbl.tv_sec,
+						   &event->event.vbl.tv_usec,
 						   true);
 		vmw_fence_obj_unreference(&fence);
 	} else {

include/drm/drm_vblank.h

@@ -54,7 +54,10 @@ struct drm_pending_vblank_event {
 	/**
 	 * @event: Actual event which will be sent to userspace.
 	 */
-	struct drm_event_vblank event;
+	union {
+		struct drm_event base;
+		struct drm_event_vblank vbl;
+	} event;
 };
 
 /**
@@ -163,6 +166,9 @@ void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
 			       struct drm_pending_vblank_event *e);
 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
 			      struct drm_pending_vblank_event *e);
+void drm_vblank_set_event(struct drm_pending_vblank_event *e,
+			  u64 *seq,
+			  ktime_t *now);
 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
 bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
 int drm_crtc_vblank_get(struct drm_crtc *crtc);