drm/i915: Add a cursor hack to allow converting legacy page flip to atomic, v3.

Do something similar to vc4, only allow updating the cursor state
in-place through a fastpath when the watermarks are unaffected. This
will allow cursor movement to be smooth, but changing cursor size or
showing/hiding cursor will still fall back so watermarks can be updated.

Only moving and changing fb is allowed.

Changes since v1:
- Set page flip to always_unused for trybot.
- Copy fence correctly, ignore plane_state->state, should be NULL.
- Check crtc_state for !active and modeset, go to slowpath if the case.
Changes since v2:
- Make error handling work correctly. (Matthew Auld)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/a8e4cb00-5171-14e5-bbe3-dadb654ff296@linux.intel.com

drivers/gpu/drm/i915/intel_atomic_plane.c

@@ -103,36 +103,24 @@ intel_plane_destroy_state(struct drm_plane *plane,
 	drm_atomic_helper_plane_destroy_state(plane, state);
 }
 
-static int intel_plane_atomic_check(struct drm_plane *plane,
-				    struct drm_plane_state *state)
+int intel_plane_atomic_check_with_state(struct intel_crtc_state *crtc_state,
+					struct intel_plane_state *intel_state)
 {
+	struct drm_plane *plane = intel_state->base.plane;
 	struct drm_i915_private *dev_priv = to_i915(plane->dev);
-	struct drm_crtc *crtc = state->crtc;
-	struct intel_crtc *intel_crtc;
-	struct intel_crtc_state *crtc_state;
+	struct drm_plane_state *state = &intel_state->base;
 	struct intel_plane *intel_plane = to_intel_plane(plane);
-	struct intel_plane_state *intel_state = to_intel_plane_state(state);
-	struct drm_crtc_state *drm_crtc_state;
 	int ret;
 
-	crtc = crtc ? crtc : plane->state->crtc;
-	intel_crtc = to_intel_crtc(crtc);
-
 	/*
 	 * Both crtc and plane->crtc could be NULL if we're updating a
 	 * property while the plane is disabled.  We don't actually have
 	 * anything driver-specific we need to test in that case, so
 	 * just return success.
 	 */
-	if (!crtc)
+	if (!intel_state->base.crtc && !plane->state->crtc)
 		return 0;
 
-	drm_crtc_state = drm_atomic_get_existing_crtc_state(state->state, crtc);
-	if (WARN_ON(!drm_crtc_state))
-		return -EINVAL;
-
-	crtc_state = to_intel_crtc_state(drm_crtc_state);
-
 	/* Clip all planes to CRTC size, or 0x0 if CRTC is disabled */
 	intel_state->clip.x1 = 0;
 	intel_state->clip.y1 = 0;
@@ -184,6 +172,31 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
 	return intel_plane_atomic_calc_changes(&crtc_state->base, state);
 }
 
+static int intel_plane_atomic_check(struct drm_plane *plane,
+				    struct drm_plane_state *state)
+{
+	struct drm_crtc *crtc = state->crtc;
+	struct drm_crtc_state *drm_crtc_state;
+
+	crtc = crtc ? crtc : plane->state->crtc;
+
+	/*
+	 * Both crtc and plane->crtc could be NULL if we're updating a
+	 * property while the plane is disabled.  We don't actually have
+	 * anything driver-specific we need to test in that case, so
+	 * just return success.
+	 */
+	if (!crtc)
+		return 0;
+
+	drm_crtc_state = drm_atomic_get_existing_crtc_state(state->state, crtc);
+	if (WARN_ON(!drm_crtc_state))
+		return -EINVAL;
+
+	return intel_plane_atomic_check_with_state(to_intel_crtc_state(drm_crtc_state),
+						   to_intel_plane_state(state));
+}
+
 static void intel_plane_atomic_update(struct drm_plane *plane,
 				      struct drm_plane_state *old_state)
 {

drivers/gpu/drm/i915/intel_display.c

@@ -14954,6 +14954,136 @@ const struct drm_plane_funcs intel_plane_funcs = {
 	.atomic_destroy_state = intel_plane_destroy_state,
 };
 
+static int
+intel_legacy_cursor_update(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_i915_private *dev_priv = to_i915(crtc->dev);
+	int ret;
+	struct drm_plane_state *old_plane_state, *new_plane_state;
+	struct intel_plane *intel_plane = to_intel_plane(plane);
+	struct drm_framebuffer *old_fb;
+	struct drm_crtc_state *crtc_state = crtc->state;
+
+	/*
+	 * When crtc is inactive or there is a modeset pending,
+	 * wait for it to complete in the slowpath
+	 */
+	if (!crtc_state->active || needs_modeset(crtc_state) ||
+	    to_intel_crtc_state(crtc_state)->update_pipe)
+		goto slow;
+
+	old_plane_state = plane->state;
+
+	/*
+	 * If any parameters change that may affect watermarks,
+	 * take the slowpath. Only changing fb or position should be
+	 * in the fastpath.
+	 */
+	if (old_plane_state->crtc != crtc ||
+	    old_plane_state->src_w != src_w ||
+	    old_plane_state->src_h != src_h ||
+	    old_plane_state->crtc_w != crtc_w ||
+	    old_plane_state->crtc_h != crtc_h ||
+	    !old_plane_state->visible ||
+	    old_plane_state->fb->modifier != fb->modifier)
+		goto slow;
+
+	new_plane_state = intel_plane_duplicate_state(plane);
+	if (!new_plane_state)
+		return -ENOMEM;
+
+	drm_atomic_set_fb_for_plane(new_plane_state, fb);
+
+	new_plane_state->src_x = src_x;
+	new_plane_state->src_y = src_y;
+	new_plane_state->src_w = src_w;
+	new_plane_state->src_h = src_h;
+	new_plane_state->crtc_x = crtc_x;
+	new_plane_state->crtc_y = crtc_y;
+	new_plane_state->crtc_w = crtc_w;
+	new_plane_state->crtc_h = crtc_h;
+
+	ret = intel_plane_atomic_check_with_state(to_intel_crtc_state(crtc->state),
+						  to_intel_plane_state(new_plane_state));
+	if (ret)
+		goto out_free;
+
+	/* Visibility changed, must take slowpath. */
+	if (!new_plane_state->visible)
+		goto slow_free;
+
+	ret = mutex_lock_interruptible(&dev_priv->drm.struct_mutex);
+	if (ret)
+		goto out_free;
+
+	if (INTEL_INFO(dev_priv)->cursor_needs_physical) {
+		int align = IS_I830(dev_priv) ? 16 * 1024 : 256;
+
+		ret = i915_gem_object_attach_phys(intel_fb_obj(fb), align);
+		if (ret) {
+			DRM_DEBUG_KMS("failed to attach phys object\n");
+			goto out_unlock;
+		}
+	} else {
+		struct i915_vma *vma;
+
+		vma = intel_pin_and_fence_fb_obj(fb, new_plane_state->rotation);
+		if (IS_ERR(vma)) {
+			DRM_DEBUG_KMS("failed to pin object\n");
+
+			ret = PTR_ERR(vma);
+			goto out_unlock;
+		}
+	}
+
+	old_fb = old_plane_state->fb;
+
+	i915_gem_track_fb(intel_fb_obj(old_fb), intel_fb_obj(fb),
+			  intel_plane->frontbuffer_bit);
+
+	/* Swap plane state */
+	new_plane_state->fence = old_plane_state->fence;
+	*to_intel_plane_state(old_plane_state) = *to_intel_plane_state(new_plane_state);
+	new_plane_state->fence = NULL;
+	new_plane_state->fb = old_fb;
+
+	intel_plane->update_plane(plane,
+				  to_intel_crtc_state(crtc->state),
+				  to_intel_plane_state(plane->state));
+
+	intel_cleanup_plane_fb(plane, new_plane_state);
+
+out_unlock:
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+out_free:
+	intel_plane_destroy_state(plane, new_plane_state);
+	return ret;
+
+slow_free:
+	intel_plane_destroy_state(plane, new_plane_state);
+slow:
+	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);
+}
+
+static const struct drm_plane_funcs intel_cursor_plane_funcs = {
+	.update_plane = intel_legacy_cursor_update,
+	.disable_plane = drm_atomic_helper_disable_plane,
+	.destroy = intel_plane_destroy,
+	.set_property = drm_atomic_helper_plane_set_property,
+	.atomic_get_property = intel_plane_atomic_get_property,
+	.atomic_set_property = intel_plane_atomic_set_property,
+	.atomic_duplicate_state = intel_plane_duplicate_state,
+	.atomic_destroy_state = intel_plane_destroy_state,
+};
+
 static struct intel_plane *
 intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
 {
@@ -15198,7 +15328,7 @@ intel_cursor_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
 	cursor->disable_plane = intel_disable_cursor_plane;
 
 	ret = drm_universal_plane_init(&dev_priv->drm, &cursor->base,
-				       0, &intel_plane_funcs,
+				       0, &intel_cursor_plane_funcs,
 				       intel_cursor_formats,
 				       ARRAY_SIZE(intel_cursor_formats),
 				       DRM_PLANE_TYPE_CURSOR,

drivers/gpu/drm/i915/intel_drv.h

@@ -1815,6 +1815,8 @@ struct drm_plane_state *intel_plane_duplicate_state(struct drm_plane *plane);
 void intel_plane_destroy_state(struct drm_plane *plane,
 			       struct drm_plane_state *state);
 extern const struct drm_plane_helper_funcs intel_plane_helper_funcs;
+int intel_plane_atomic_check_with_state(struct intel_crtc_state *crtc_state,
+					struct intel_plane_state *intel_state);
 
 /* intel_color.c */
 void intel_color_init(struct drm_crtc *crtc);