drm/vc4: update cursors asynchronously through atomic

Add support for async updates of cursors by using the new atomic
interface for that. Basically what this commit does is do what
vc4_update_plane() did but through atomic.

v7: Place the drm_atomic_set_fb_for_plane() call after the new
    FB has been applied to the HW to avoid possible use-after-free
    issues
v6: add missing drm_atomic_set_fb_for_plane() in
    vc4_plane_atomic_async_update() (Boris Brezillon)
v5: add missing call to vc4_plane_atomic_check() (Eric Anholt)
v4: add drm_atomic_helper_async() commit (Eric Anholt)
v3: move size checks back to drivers (Ville Syrjälä)
v2: move fb setting to core and use new state (Eric Anholt)

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180330085445.31726-1-boris.brezillon@bootlin.com

drivers/gpu/drm/vc4/vc4_kms.c

@@ -90,6 +90,26 @@ static int vc4_atomic_commit(struct drm_device *dev,
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	int ret;
 
+	if (state->async_update) {
+		ret = down_interruptible(&vc4->async_modeset);
+		if (ret)
+			return ret;
+
+		ret = drm_atomic_helper_prepare_planes(dev, state);
+		if (ret) {
+			up(&vc4->async_modeset);
+			return ret;
+		}
+
+		drm_atomic_helper_async_commit(dev, state);
+
+		drm_atomic_helper_cleanup_planes(dev, state);
+
+		up(&vc4->async_modeset);
+
+		return 0;
+	}
+
 	ret = drm_atomic_helper_setup_commit(state, nonblock);
 	if (ret)
 		return ret;

drivers/gpu/drm/vc4/vc4_plane.c

@@ -741,6 +741,57 @@ void vc4_plane_async_set_fb(struct drm_plane *plane, struct drm_framebuffer *fb)
 	vc4_state->dlist[vc4_state->ptr0_offset] = addr;
 }
 
+static void vc4_plane_atomic_async_update(struct drm_plane *plane,
+					  struct drm_plane_state *state)
+{
+	struct vc4_plane_state *vc4_state = to_vc4_plane_state(plane->state);
+
+	if (plane->state->fb != state->fb) {
+		vc4_plane_async_set_fb(plane, state->fb);
+		drm_atomic_set_fb_for_plane(plane->state, state->fb);
+	}
+
+	/* Set the cursor's position on the screen.  This is the
+	 * expected change from the drm_mode_cursor_universal()
+	 * helper.
+	 */
+	plane->state->crtc_x = state->crtc_x;
+	plane->state->crtc_y = state->crtc_y;
+
+	/* Allow changing the start position within the cursor BO, if
+	 * that matters.
+	 */
+	plane->state->src_x = state->src_x;
+	plane->state->src_y = state->src_y;
+
+	/* Update the display list based on the new crtc_x/y. */
+	vc4_plane_atomic_check(plane, plane->state);
+
+	/* Note that we can't just call vc4_plane_write_dlist()
+	 * because that would smash the context data that the HVS is
+	 * currently using.
+	 */
+	writel(vc4_state->dlist[vc4_state->pos0_offset],
+	       &vc4_state->hw_dlist[vc4_state->pos0_offset]);
+	writel(vc4_state->dlist[vc4_state->pos2_offset],
+	       &vc4_state->hw_dlist[vc4_state->pos2_offset]);
+	writel(vc4_state->dlist[vc4_state->ptr0_offset],
+	       &vc4_state->hw_dlist[vc4_state->ptr0_offset]);
+}
+
+static int vc4_plane_atomic_async_check(struct drm_plane *plane,
+					struct drm_plane_state *state)
+{
+	/* No configuring new scaling in the fast path. */
+	if (plane->state->crtc_w != state->crtc_w ||
+	    plane->state->crtc_h != state->crtc_h ||
+	    plane->state->src_w != state->src_w ||
+	    plane->state->src_h != state->src_h)
+		return -EINVAL;
+
+	return 0;
+}
+
 static int vc4_prepare_fb(struct drm_plane *plane,
 			  struct drm_plane_state *state)
 {
@@ -780,6 +831,8 @@ static const struct drm_plane_helper_funcs vc4_plane_helper_funcs = {
 	.atomic_update = vc4_plane_atomic_update,
 	.prepare_fb = vc4_prepare_fb,
 	.cleanup_fb = vc4_cleanup_fb,
+	.atomic_async_check = vc4_plane_atomic_async_check,
+	.atomic_async_update = vc4_plane_atomic_async_update,
 };
 
 static void vc4_plane_destroy(struct drm_plane *plane)
@@ -788,82 +841,6 @@ static void vc4_plane_destroy(struct drm_plane *plane)
 	drm_plane_cleanup(plane);
 }
 
-/* Implements immediate (non-vblank-synced) updates of the cursor
- * position, or falls back to the atomic helper otherwise.
- */
-static int
-vc4_update_plane(struct drm_plane *plane,
-		 struct drm_crtc *crtc,
-		 struct drm_framebuffer *fb,
-		 int crtc_x, int crtc_y,
-		 unsigned int crtc_w, unsigned int crtc_h,
-		 uint32_t src_x, uint32_t src_y,
-		 uint32_t src_w, uint32_t src_h,
-		 struct drm_modeset_acquire_ctx *ctx)
-{
-	struct drm_plane_state *plane_state;
-	struct vc4_plane_state *vc4_state;
-
-	if (plane != crtc->cursor)
-		goto out;
-
-	plane_state = plane->state;
-	vc4_state = to_vc4_plane_state(plane_state);
-
-	if (!plane_state)
-		goto out;
-
-	/* No configuring new scaling in the fast path. */
-	if (crtc_w != plane_state->crtc_w ||
-	    crtc_h != plane_state->crtc_h ||
-	    src_w != plane_state->src_w ||
-	    src_h != plane_state->src_h) {
-		goto out;
-	}
-
-	if (fb != plane_state->fb) {
-		drm_atomic_set_fb_for_plane(plane->state, fb);
-		vc4_plane_async_set_fb(plane, fb);
-	}
-
-	/* Set the cursor's position on the screen.  This is the
-	 * expected change from the drm_mode_cursor_universal()
-	 * helper.
-	 */
-	plane_state->crtc_x = crtc_x;
-	plane_state->crtc_y = crtc_y;
-
-	/* Allow changing the start position within the cursor BO, if
-	 * that matters.
-	 */
-	plane_state->src_x = src_x;
-	plane_state->src_y = src_y;
-
-	/* Update the display list based on the new crtc_x/y. */
-	vc4_plane_atomic_check(plane, plane_state);
-
-	/* Note that we can't just call vc4_plane_write_dlist()
-	 * because that would smash the context data that the HVS is
-	 * currently using.
-	 */
-	writel(vc4_state->dlist[vc4_state->pos0_offset],
-	       &vc4_state->hw_dlist[vc4_state->pos0_offset]);
-	writel(vc4_state->dlist[vc4_state->pos2_offset],
-	       &vc4_state->hw_dlist[vc4_state->pos2_offset]);
-	writel(vc4_state->dlist[vc4_state->ptr0_offset],
-	       &vc4_state->hw_dlist[vc4_state->ptr0_offset]);
-
-	return 0;
-
-out:
-	return drm_atomic_helper_update_plane(plane, crtc, fb,
-					      crtc_x, crtc_y,
-					      crtc_w, crtc_h,
-					      src_x, src_y,
-					      src_w, src_h,
-					      ctx);
-}
-
 static bool vc4_format_mod_supported(struct drm_plane *plane,
 				     uint32_t format,
 				     uint64_t modifier)
@@ -891,7 +868,7 @@ static bool vc4_format_mod_supported(struct drm_plane *plane,
 }
 
 static const struct drm_plane_funcs vc4_plane_funcs = {
-	.update_plane = vc4_update_plane,
+	.update_plane = drm_atomic_helper_update_plane,
 	.disable_plane = drm_atomic_helper_disable_plane,
 	.destroy = vc4_plane_destroy,
 	.set_property = NULL,