drm/msm/mdp5: Assign a 'right hwpipe' to plane state

If the drm_plane has a source width that's greater than the max width
supported by a SSPP (2560 pixels on 8x96), then we assign a 'r_hwpipe'
to it in mdp5_plane_atomic_check().

TODO: There are a few scenarios where the hwpipe assignments aren't
recommended by HW. For example, an assignment which results in a
drm_plane to of two different types of hwpipes (say RGB0 on left
and DMA1 on right) is not recommended.
Also, hwpipes have a priority mapping, where the higher priority pipe
needs to be staged on left LM, and the lower priority needs to be
staged on the right LM. For example, the priority order for VIG pipes
in decreasing order of priority is VIG0, VIG1, VIG2, and VIG3. So, VIG0
on left and VIG1 on right is a correct configuration, but VIG1 on left
and VIG0 on right isn't. These scenarios are ignored for now for the
sake of simplicity.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h

@@ -104,6 +104,7 @@ struct mdp5_plane_state {
 	struct drm_plane_state base;
 
 	struct mdp5_hw_pipe *hwpipe;
+	struct mdp5_hw_pipe *r_hwpipe;	/* right hwpipe */
 
 	/* aligned with property */
 	uint8_t premultiplied;

drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c

@@ -177,9 +177,14 @@ mdp5_plane_atomic_print_state(struct drm_printer *p,
 		const struct drm_plane_state *state)
 {
 	struct mdp5_plane_state *pstate = to_mdp5_plane_state(state);
+	struct mdp5_kms *mdp5_kms = get_kms(state->plane);
 
 	drm_printf(p, "\thwpipe=%s\n", pstate->hwpipe ?
 			pstate->hwpipe->name : "(null)");
+	if (mdp5_kms->caps & MDP_CAP_SRC_SPLIT)
+		drm_printf(p, "\tright-hwpipe=%s\n",
+			   pstate->r_hwpipe ? pstate->r_hwpipe->name :
+					      "(null)");
 	drm_printf(p, "\tpremultiplied=%u\n", pstate->premultiplied);
 	drm_printf(p, "\tzpos=%u\n", pstate->zpos);
 	drm_printf(p, "\talpha=%u\n", pstate->alpha);
@@ -299,7 +304,9 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state,
 	struct drm_plane_state *old_state = plane->state;
 	struct mdp5_cfg *config = mdp5_cfg_get_config(get_kms(plane)->cfg);
 	bool new_hwpipe = false;
+	bool need_right_hwpipe = false;
 	uint32_t max_width, max_height;
+	bool out_of_bounds = false;
 	uint32_t caps = 0;
 	struct drm_rect clip;
 	int min_scale, max_scale;
@@ -312,7 +319,23 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state,
 	max_height = config->hw->lm.max_height << 16;
 
 	/* Make sure source dimensions are within bounds. */
-	if ((state->src_w > max_width) || (state->src_h > max_height)) {
+	if (state->src_h > max_height)
+		out_of_bounds = true;
+
+	if (state->src_w > max_width) {
+		/* If source split is supported, we can go up to 2x
+		 * the max LM width, but we'd need to stage another
+		 * hwpipe to the right LM. So, the drm_plane would
+		 * consist of 2 hwpipes.
+		 */
+		if (config->hw->mdp.caps & MDP_CAP_SRC_SPLIT &&
+		    (state->src_w <= 2 * max_width))
+			need_right_hwpipe = true;
+		else
+			out_of_bounds = true;
+	}
+
+	if (out_of_bounds) {
 		struct drm_rect src = drm_plane_state_src(state);
 		DBG("Invalid source size "DRM_RECT_FP_FMT,
 				DRM_RECT_FP_ARG(&src));
@@ -363,6 +386,15 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state,
 		if (!mdp5_state->hwpipe || (caps & ~mdp5_state->hwpipe->caps))
 			new_hwpipe = true;
 
+		/*
+		 * (re)allocte hw pipe if we're either requesting for 2 hw pipes
+		 * or we're switching from 2 hw pipes to 1 hw pipe because the
+		 * new src_w can be supported by 1 hw pipe itself.
+		 */
+		if ((need_right_hwpipe && !mdp5_state->r_hwpipe) ||
+		    (!need_right_hwpipe && mdp5_state->r_hwpipe))
+			new_hwpipe = true;
+
 		if (mdp5_kms->smp) {
 			const struct mdp_format *format =
 				to_mdp_format(msm_framebuffer_format(state->fb));
@@ -381,13 +413,36 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state,
 			 * it available for other planes?
 			 */
 			struct mdp5_hw_pipe *old_hwpipe = mdp5_state->hwpipe;
+			struct mdp5_hw_pipe *old_right_hwpipe =
+							  mdp5_state->r_hwpipe;
+
 			mdp5_state->hwpipe = mdp5_pipe_assign(state->state,
 					plane, caps, blkcfg);
 			if (IS_ERR(mdp5_state->hwpipe)) {
 				DBG("%s: failed to assign hwpipe!", plane->name);
 				return PTR_ERR(mdp5_state->hwpipe);
 			}
+
+			if (need_right_hwpipe) {
+				mdp5_state->r_hwpipe =
+					mdp5_pipe_assign(state->state, plane,
+							 caps, blkcfg);
+				if (IS_ERR(mdp5_state->r_hwpipe)) {
+					DBG("%s: failed to assign right hwpipe",
+					    plane->name);
+					return PTR_ERR(mdp5_state->r_hwpipe);
+				}
+			} else {
+				/*
+				 * set it to NULL so that the driver knows we
+				 * don't have a right hwpipe when committing a
+				 * new state
+				 */
+				mdp5_state->r_hwpipe = NULL;
+			}
+
 			mdp5_pipe_release(state->state, old_hwpipe);
+			mdp5_pipe_release(state->state, old_right_hwpipe);
 		}
 	}