drm: Add local 'plane' variable for primary/cursor planes

Make the code a bit more readable by storing the plane pointer in a
local variable rather than having to do crtc->{primary,cursor} all the
time.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180322152313.6561-6-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 7a973ada..8552ed4 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -402,6 +402,7 @@ int drm_mode_getcrtc(struct drm_device *dev,
 {
 	struct drm_mode_crtc *crtc_resp = data;
 	struct drm_crtc *crtc;
+	struct drm_plane *plane;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 		return -EINVAL;
@@ -410,21 +411,23 @@ int drm_mode_getcrtc(struct drm_device *dev,
 	if (!crtc)
 		return -ENOENT;
 
+	plane = crtc->primary;
+
 	crtc_resp->gamma_size = crtc->gamma_size;
 
-	drm_modeset_lock(&crtc->primary->mutex, NULL);
-	if (crtc->primary->state && crtc->primary->state->fb)
-		crtc_resp->fb_id = crtc->primary->state->fb->base.id;
-	else if (!crtc->primary->state && crtc->primary->fb)
-		crtc_resp->fb_id = crtc->primary->fb->base.id;
+	drm_modeset_lock(&plane->mutex, NULL);
+	if (plane->state && plane->state->fb)
+		crtc_resp->fb_id = plane->state->fb->base.id;
+	else if (!plane->state && plane->fb)
+		crtc_resp->fb_id = plane->fb->base.id;
 	else
 		crtc_resp->fb_id = 0;
 
-	if (crtc->primary->state) {
-		crtc_resp->x = crtc->primary->state->src_x >> 16;
-		crtc_resp->y = crtc->primary->state->src_y >> 16;
+	if (plane->state) {
+		crtc_resp->x = plane->state->src_x >> 16;
+		crtc_resp->y = plane->state->src_y >> 16;
 	}
-	drm_modeset_unlock(&crtc->primary->mutex);
+	drm_modeset_unlock(&plane->mutex);
 
 	drm_modeset_lock(&crtc->mutex, NULL);
 	if (crtc->state) {
@@ -554,6 +557,7 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 	struct drm_mode_config *config = &dev->mode_config;
 	struct drm_mode_crtc *crtc_req = data;
 	struct drm_crtc *crtc;
+	struct drm_plane *plane;
 	struct drm_connector **connector_set = NULL, *connector;
 	struct drm_framebuffer *fb = NULL;
 	struct drm_display_mode *mode = NULL;
@@ -580,6 +584,8 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 	}
 	DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
 
+	plane = crtc->primary;
+
 	mutex_lock(&crtc->dev->mode_config.mutex);
 	drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
 retry:
@@ -590,12 +596,12 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 		/* If we have a mode we need a framebuffer. */
 		/* If we pass -1, set the mode with the currently bound fb */
 		if (crtc_req->fb_id == -1) {
-			if (!crtc->primary->fb) {
+			if (!plane->fb) {
 				DRM_DEBUG_KMS("CRTC doesn't have current FB\n");
 				ret = -EINVAL;
 				goto out;
 			}
-			fb = crtc->primary->fb;
+			fb = plane->fb;
 			/* Make refcounting symmetric with the lookup path. */
 			drm_framebuffer_get(fb);
 		} else {
@@ -627,8 +633,8 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 		 * match real hardware capabilities. Skip the check in that
 		 * case.
 		 */
-		if (!crtc->primary->format_default) {
-			ret = drm_plane_check_pixel_format(crtc->primary,
+		if (!plane->format_default) {
+			ret = drm_plane_check_pixel_format(plane,
 							   fb->format->format,
 							   fb->modifier);
 			if (ret) {