drm/atomic: Use explicit old/new state in drm_atomic_plane_check()

Convert drm_atomic_plane_check() over to using explicit old vs. new
plane states. Avoids the confusion of "what does plane->state mean
again?".

v2: Stick to the multi-stage logic in plane_switching_crtc() (Daniel)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20181106191624.2207-1-ville.syrjala@linux.intel.com

drivers/gpu/drm/drm_atomic.c

@@ -487,14 +487,13 @@ drm_atomic_get_plane_state(struct drm_atomic_state *state,
 EXPORT_SYMBOL(drm_atomic_get_plane_state);
 
 static bool
-plane_switching_crtc(struct drm_atomic_state *state,
-		     struct drm_plane *plane,
-		     struct drm_plane_state *plane_state)
+plane_switching_crtc(const struct drm_plane_state *old_plane_state,
+		     const struct drm_plane_state *new_plane_state)
 {
-	if (!plane->state->crtc || !plane_state->crtc)
+	if (!old_plane_state->crtc || !new_plane_state->crtc)
 		return false;
 
-	if (plane->state->crtc == plane_state->crtc)
+	if (old_plane_state->crtc == new_plane_state->crtc)
 		return false;
 
 	/* This could be refined, but currently there's no helper or driver code
@@ -507,88 +506,95 @@ plane_switching_crtc(struct drm_atomic_state *state,
 
 /**
  * drm_atomic_plane_check - check plane state
- * @plane: plane to check
- * @state: plane state to check
+ * @old_plane_state: old plane state to check
+ * @new_plane_state: new plane state to check
  *
  * Provides core sanity checks for plane state.
  *
  * RETURNS:
  * Zero on success, error code on failure
  */
-static int drm_atomic_plane_check(struct drm_plane *plane,
-		struct drm_plane_state *state)
+static int drm_atomic_plane_check(const struct drm_plane_state *old_plane_state,
+				  const struct drm_plane_state *new_plane_state)
 {
+	struct drm_plane *plane = new_plane_state->plane;
+	struct drm_crtc *crtc = new_plane_state->crtc;
+	const struct drm_framebuffer *fb = new_plane_state->fb;
 	unsigned int fb_width, fb_height;
 	int ret;
 
 	/* either *both* CRTC and FB must be set, or neither */
-	if (state->crtc && !state->fb) {
+	if (crtc && !fb) {
 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] CRTC set but no FB\n",
 				 plane->base.id, plane->name);
 		return -EINVAL;
-	} else if (state->fb && !state->crtc) {
+	} else if (fb && !crtc) {
 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] FB set but no CRTC\n",
 				 plane->base.id, plane->name);
 		return -EINVAL;
 	}
 
 	/* if disabled, we don't care about the rest of the state: */
-	if (!state->crtc)
+	if (!crtc)
 		return 0;
 
 	/* Check whether this plane is usable on this CRTC */
-	if (!(plane->possible_crtcs & drm_crtc_mask(state->crtc))) {
+	if (!(plane->possible_crtcs & drm_crtc_mask(crtc))) {
 		DRM_DEBUG_ATOMIC("Invalid [CRTC:%d:%s] for [PLANE:%d:%s]\n",
-				 state->crtc->base.id, state->crtc->name,
+				 crtc->base.id, crtc->name,
 				 plane->base.id, plane->name);
 		return -EINVAL;
 	}
 
 	/* Check whether this plane supports the fb pixel format. */
-	ret = drm_plane_check_pixel_format(plane, state->fb->format->format,
-					   state->fb->modifier);
+	ret = drm_plane_check_pixel_format(plane, fb->format->format,
+					   fb->modifier);
 	if (ret) {
 		struct drm_format_name_buf format_name;
 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] invalid pixel format %s, modifier 0x%llx\n",
 				 plane->base.id, plane->name,
-				 drm_get_format_name(state->fb->format->format,
+				 drm_get_format_name(fb->format->format,
 						     &format_name),
-				 state->fb->modifier);
+				 fb->modifier);
 		return ret;
 	}
 
 	/* Give drivers some help against integer overflows */
-	if (state->crtc_w > INT_MAX ||
-	    state->crtc_x > INT_MAX - (int32_t) state->crtc_w ||
-	    state->crtc_h > INT_MAX ||
-	    state->crtc_y > INT_MAX - (int32_t) state->crtc_h) {
+	if (new_plane_state->crtc_w > INT_MAX ||
+	    new_plane_state->crtc_x > INT_MAX - (int32_t) new_plane_state->crtc_w ||
+	    new_plane_state->crtc_h > INT_MAX ||
+	    new_plane_state->crtc_y > INT_MAX - (int32_t) new_plane_state->crtc_h) {
 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] invalid CRTC coordinates %ux%u+%d+%d\n",
 				 plane->base.id, plane->name,
-				 state->crtc_w, state->crtc_h,
-				 state->crtc_x, state->crtc_y);
+				 new_plane_state->crtc_w, new_plane_state->crtc_h,
+				 new_plane_state->crtc_x, new_plane_state->crtc_y);
 		return -ERANGE;
 	}
 
-	fb_width = state->fb->width << 16;
-	fb_height = state->fb->height << 16;
+	fb_width = fb->width << 16;
+	fb_height = fb->height << 16;
 
 	/* Make sure source coordinates are inside the fb. */
-	if (state->src_w > fb_width ||
-	    state->src_x > fb_width - state->src_w ||
-	    state->src_h > fb_height ||
-	    state->src_y > fb_height - state->src_h) {
+	if (new_plane_state->src_w > fb_width ||
+	    new_plane_state->src_x > fb_width - new_plane_state->src_w ||
+	    new_plane_state->src_h > fb_height ||
+	    new_plane_state->src_y > fb_height - new_plane_state->src_h) {
 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] invalid source coordinates "
 				 "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
 				 plane->base.id, plane->name,
-				 state->src_w >> 16, ((state->src_w & 0xffff) * 15625) >> 10,
-				 state->src_h >> 16, ((state->src_h & 0xffff) * 15625) >> 10,
-				 state->src_x >> 16, ((state->src_x & 0xffff) * 15625) >> 10,
-				 state->src_y >> 16, ((state->src_y & 0xffff) * 15625) >> 10,
-				 state->fb->width, state->fb->height);
+				 new_plane_state->src_w >> 16,
+				 ((new_plane_state->src_w & 0xffff) * 15625) >> 10,
+				 new_plane_state->src_h >> 16,
+				 ((new_plane_state->src_h & 0xffff) * 15625) >> 10,
+				 new_plane_state->src_x >> 16,
+				 ((new_plane_state->src_x & 0xffff) * 15625) >> 10,
+				 new_plane_state->src_y >> 16,
+				 ((new_plane_state->src_y & 0xffff) * 15625) >> 10,
+				 fb->width, fb->height);
 		return -ENOSPC;
 	}
 
-	if (plane_switching_crtc(state->state, plane, state)) {
+	if (plane_switching_crtc(old_plane_state, new_plane_state)) {
 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] switching CRTC directly\n",
 				 plane->base.id, plane->name);
 		return -EINVAL;
@@ -961,7 +967,8 @@ int drm_atomic_check_only(struct drm_atomic_state *state)
 	struct drm_device *dev = state->dev;
 	struct drm_mode_config *config = &dev->mode_config;
 	struct drm_plane *plane;
-	struct drm_plane_state *plane_state;
+	struct drm_plane_state *old_plane_state;
+	struct drm_plane_state *new_plane_state;
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *old_crtc_state;
 	struct drm_crtc_state *new_crtc_state;
@@ -971,8 +978,8 @@ int drm_atomic_check_only(struct drm_atomic_state *state)
 
 	DRM_DEBUG_ATOMIC("checking %p\n", state);
 
-	for_each_new_plane_in_state(state, plane, plane_state, i) {
-		ret = drm_atomic_plane_check(plane, plane_state);
+	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
+		ret = drm_atomic_plane_check(old_plane_state, new_plane_state);
 		if (ret) {
 			DRM_DEBUG_ATOMIC("[PLANE:%d:%s] atomic core check failed\n",
 					 plane->base.id, plane->name);