drm/vc4: Add more display planes to each CRTC.

Previously we only did the primary and cursor plane, but overlay
planes are useful and just require this setup to add, since all planes
go into the HVS display list in the same way.
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/vc4/vc4_crtc.c

@@ -657,9 +657,9 @@ static int vc4_crtc_bind(struct device *dev, struct device *master, void *data)
 	struct vc4_dev *vc4 = to_vc4_dev(drm);
 	struct vc4_crtc *vc4_crtc;
 	struct drm_crtc *crtc;
-	struct drm_plane *primary_plane, *cursor_plane;
+	struct drm_plane *primary_plane, *cursor_plane, *destroy_plane, *temp;
 	const struct of_device_id *match;
-	int ret;
+	int ret, i;
 
 	vc4_crtc = devm_kzalloc(dev, sizeof(*vc4_crtc), GFP_KERNEL);
 	if (!vc4_crtc)
@@ -688,27 +688,49 @@ static int vc4_crtc_bind(struct device *dev, struct device *master, void *data)
 		goto err;
 	}
 
-	cursor_plane = vc4_plane_init(drm, DRM_PLANE_TYPE_CURSOR);
-	if (IS_ERR(cursor_plane)) {
-		dev_err(dev, "failed to construct cursor plane\n");
-		ret = PTR_ERR(cursor_plane);
-		goto err_primary;
-	}
-
-	drm_crtc_init_with_planes(drm, crtc, primary_plane, cursor_plane,
+	drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
 				  &vc4_crtc_funcs, NULL);
 	drm_crtc_helper_add(crtc, &vc4_crtc_helper_funcs);
 	primary_plane->crtc = crtc;
-	cursor_plane->crtc = crtc;
 	vc4->crtc[drm_crtc_index(crtc)] = vc4_crtc;
 	vc4_crtc->channel = vc4_crtc->data->hvs_channel;
 
+	/* Set up some arbitrary number of planes.  We're not limited
+	 * by a set number of physical registers, just the space in
+	 * the HVS (16k) and how small an plane can be (28 bytes).
+	 * However, each plane we set up takes up some memory, and
+	 * increases the cost of looping over planes, which atomic
+	 * modesetting does quite a bit.  As a result, we pick a
+	 * modest number of planes to expose, that should hopefully
+	 * still cover any sane usecase.
+	 */
+	for (i = 0; i < 8; i++) {
+		struct drm_plane *plane =
+			vc4_plane_init(drm, DRM_PLANE_TYPE_OVERLAY);
+
+		if (IS_ERR(plane))
+			continue;
+
+		plane->possible_crtcs = 1 << drm_crtc_index(crtc);
+	}
+
+	/* Set up the legacy cursor after overlay initialization,
+	 * since we overlay planes on the CRTC in the order they were
+	 * initialized.
+	 */
+	cursor_plane = vc4_plane_init(drm, DRM_PLANE_TYPE_CURSOR);
+	if (!IS_ERR(cursor_plane)) {
+		cursor_plane->possible_crtcs = 1 << drm_crtc_index(crtc);
+		cursor_plane->crtc = crtc;
+		crtc->cursor = cursor_plane;
+	}
+
 	CRTC_WRITE(PV_INTEN, 0);
 	CRTC_WRITE(PV_INTSTAT, PV_INT_VFP_START);
 	ret = devm_request_irq(dev, platform_get_irq(pdev, 0),
 			       vc4_crtc_irq_handler, 0, "vc4 crtc", vc4_crtc);
 	if (ret)
-		goto err_cursor;
+		goto err_destroy_planes;
 
 	vc4_set_crtc_possible_masks(drm, crtc);
 
@@ -716,10 +738,12 @@ static int vc4_crtc_bind(struct device *dev, struct device *master, void *data)
 
 	return 0;
 
-err_cursor:
-	cursor_plane->funcs->destroy(cursor_plane);
-err_primary:
-	primary_plane->funcs->destroy(primary_plane);
+err_destroy_planes:
+	list_for_each_entry_safe(destroy_plane, temp,
+				 &drm->mode_config.plane_list, head) {
+		if (destroy_plane->possible_crtcs == 1 << drm_crtc_index(crtc))
+		    destroy_plane->funcs->destroy(destroy_plane);
+	}
 err:
 	return ret;
 }