drm/i915: Switch to unified plane cursor handling (v4)

The DRM core will translate calls to legacy cursor ioctls into universal
cursor calls automatically, so there's no need to maintain the legacy
cursor support.  This greatly simplifies the transition since we don't
have to handle reference counting differently depending on which cursor
interface was called.

The aim here is to transition to the universal plane interface with
minimal code change.  There's a lot of cleanup that can be done (e.g.,
using state stored in crtc->cursor->fb rather than intel_crtc) that is
left to future patches.

v4:
 - Drop drm_gem_object_unreference() that is no longer needed now that
   we receive the GEM obj directly rather than looking up the ID.
v3:
 - Pass cursor obj to intel_crtc_cursor_set_obj() if cursor fb changes,
   even if 'visible' is false.  intel_crtc_cursor_set_obj() will notice
   that the cursor isn't visible and disable it properly, but we still
   need to get intel_crtc->cursor_addr set properly so that we behave
   properly if the cursor becomes visible again in the future without
   changing the cursor buffer (noted by Chris Wilson and verified
   via i-g-t kms_cursor_crc).
 - s/drm_plane_init/drm_universal_plane_init/.  Due to type
   compatibility between enum and bool, everything actually works
   correctly with the wrong init call, except for the type of plane that
   gets exposed to userspace (it shows up as type 'primary' rather than
   type 'cursor').
v2:
 - Remove duplicate dimension checks on cursor
 - Drop explicit cursor disable from crtc destroy (fb & plane
   destruction will take care of that now)
 - Use DRM plane helper to check update parameters

Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Pallavi G<pallavi.g@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -68,6 +68,11 @@ static const uint32_t intel_primary_formats_gen4[] = {
 	DRM_FORMAT_ABGR2101010,
 };
 
+/* Cursor formats */
+static const uint32_t intel_cursor_formats[] = {
+	DRM_FORMAT_ARGB8888,
+};
+
 #define DIV_ROUND_CLOSEST_ULL(ll, d)	\
 ({ unsigned long long _tmp = (ll)+(d)/2; do_div(_tmp, d); _tmp; })
 
@@ -8044,8 +8049,8 @@ static void intel_crtc_update_cursor(struct drm_crtc *crtc,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe;
-	int x = intel_crtc->cursor_x;
-	int y = intel_crtc->cursor_y;
+	int x = crtc->cursor_x;
+	int y = crtc->cursor_y;
 	u32 base = 0, pos = 0;
 
 	if (on)
@@ -8180,7 +8185,6 @@ static int intel_crtc_cursor_set_obj(struct drm_crtc *crtc,
 	if (intel_crtc->cursor_bo) {
 		if (!INTEL_INFO(dev)->cursor_needs_physical)
 			i915_gem_object_unpin_from_display_plane(intel_crtc->cursor_bo);
-		drm_gem_object_unreference(&intel_crtc->cursor_bo->base);
 	}
 
 	mutex_unlock(&dev->struct_mutex);
@@ -8208,38 +8212,6 @@ fail:
 	return ret;
 }
 
-static int intel_crtc_cursor_set(struct drm_crtc *crtc,
-				 struct drm_file *file,
-				 uint32_t handle,
-				 uint32_t width, uint32_t height)
-{
-	struct drm_device *dev = crtc->dev;
-	struct drm_i915_gem_object *obj;
-
-	if (handle) {
-		obj = to_intel_bo(drm_gem_object_lookup(dev, file, handle));
-		if (&obj->base == NULL)
-			return -ENOENT;
-	} else {
-		obj = NULL;
-	}
-
-	return intel_crtc_cursor_set_obj(crtc, obj, width, height);
-}
-
-static int intel_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
-{
-	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
-
-	intel_crtc->cursor_x = clamp_t(int, x, SHRT_MIN, SHRT_MAX);
-	intel_crtc->cursor_y = clamp_t(int, y, SHRT_MIN, SHRT_MAX);
-
-	if (intel_crtc->active)
-		intel_crtc_update_cursor(crtc, intel_crtc->cursor_bo != NULL);
-
-	return 0;
-}
-
 static void intel_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
 				 u16 *blue, uint32_t start, uint32_t size)
 {
@@ -8885,8 +8857,6 @@ static void intel_crtc_destroy(struct drm_crtc *crtc)
 		kfree(work);
 	}
 
-	intel_crtc_cursor_set(crtc, NULL, 0, 0, 0);
-
 	drm_crtc_cleanup(crtc);
 
 	kfree(intel_crtc);
@@ -10942,8 +10912,6 @@ out_config:
 }
 
 static const struct drm_crtc_funcs intel_crtc_funcs = {
-	.cursor_set = intel_crtc_cursor_set,
-	.cursor_move = intel_crtc_cursor_move,
 	.gamma_set = intel_crtc_gamma_set,
 	.set_config = intel_crtc_set_config,
 	.destroy = intel_crtc_destroy,
@@ -11196,7 +11164,8 @@ intel_primary_plane_setplane(struct drm_plane *plane, struct drm_crtc *crtc,
 	return 0;
 }
 
-static void intel_primary_plane_destroy(struct drm_plane *plane)
+/* Common destruction function for both primary and cursor planes */
+static void intel_plane_destroy(struct drm_plane *plane)
 {
 	struct intel_plane *intel_plane = to_intel_plane(plane);
 	drm_plane_cleanup(plane);
@@ -11206,7 +11175,7 @@ static void intel_primary_plane_destroy(struct drm_plane *plane)
 static const struct drm_plane_funcs intel_primary_plane_funcs = {
 	.update_plane = intel_primary_plane_setplane,
 	.disable_plane = intel_primary_plane_disable,
-	.destroy = intel_primary_plane_destroy,
+	.destroy = intel_plane_destroy,
 };
 
 static struct drm_plane *intel_primary_plane_create(struct drm_device *dev,
@@ -11242,11 +11211,100 @@ static struct drm_plane *intel_primary_plane_create(struct drm_device *dev,
 	return &primary->base;
 }
 
+static int
+intel_cursor_plane_disable(struct drm_plane *plane)
+{
+	if (!plane->fb)
+		return 0;
+
+	BUG_ON(!plane->crtc);
+
+	return intel_crtc_cursor_set_obj(plane->crtc, NULL, 0, 0);
+}
+
+static int
+intel_cursor_plane_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 intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
+	struct drm_i915_gem_object *obj = intel_fb->obj;
+	struct drm_rect dest = {
+		/* integer pixels */
+		.x1 = crtc_x,
+		.y1 = crtc_y,
+		.x2 = crtc_x + crtc_w,
+		.y2 = crtc_y + crtc_h,
+	};
+	struct drm_rect src = {
+		/* 16.16 fixed point */
+		.x1 = src_x,
+		.y1 = src_y,
+		.x2 = src_x + src_w,
+		.y2 = src_y + src_h,
+	};
+	const struct drm_rect clip = {
+		/* integer pixels */
+		.x2 = intel_crtc->config.pipe_src_w,
+		.y2 = intel_crtc->config.pipe_src_h,
+	};
+	bool visible;
+	int ret;
+
+	ret = drm_plane_helper_check_update(plane, crtc, fb,
+					    &src, &dest, &clip,
+					    DRM_PLANE_HELPER_NO_SCALING,
+					    DRM_PLANE_HELPER_NO_SCALING,
+					    true, true, &visible);
+	if (ret)
+		return ret;
+
+	crtc->cursor_x = crtc_x;
+	crtc->cursor_y = crtc_y;
+	if (fb != crtc->cursor->fb) {
+		return intel_crtc_cursor_set_obj(crtc, obj, crtc_w, crtc_h);
+	} else {
+		intel_crtc_update_cursor(crtc, visible);
+		return 0;
+	}
+}
+static const struct drm_plane_funcs intel_cursor_plane_funcs = {
+	.update_plane = intel_cursor_plane_update,
+	.disable_plane = intel_cursor_plane_disable,
+	.destroy = intel_plane_destroy,
+};
+
+static struct drm_plane *intel_cursor_plane_create(struct drm_device *dev,
+						   int pipe)
+{
+	struct intel_plane *cursor;
+
+	cursor = kzalloc(sizeof(*cursor), GFP_KERNEL);
+	if (cursor == NULL)
+		return NULL;
+
+	cursor->can_scale = false;
+	cursor->max_downscale = 1;
+	cursor->pipe = pipe;
+	cursor->plane = pipe;
+
+	drm_universal_plane_init(dev, &cursor->base, 0,
+				 &intel_cursor_plane_funcs,
+				 intel_cursor_formats,
+				 ARRAY_SIZE(intel_cursor_formats),
+				 DRM_PLANE_TYPE_CURSOR);
+	return &cursor->base;
+}
+
 static void intel_crtc_init(struct drm_device *dev, int pipe)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc;
-	struct drm_plane *primary;
+	struct drm_plane *primary = NULL;
+	struct drm_plane *cursor = NULL;
 	int i, ret;
 
 	intel_crtc = kzalloc(sizeof(*intel_crtc), GFP_KERNEL);
@@ -11254,13 +11312,17 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
 		return;
 
 	primary = intel_primary_plane_create(dev, pipe);
+	if (!primary)
+		goto fail;
+
+	cursor = intel_cursor_plane_create(dev, pipe);
+	if (!cursor)
+		goto fail;
+
 	ret = drm_crtc_init_with_planes(dev, &intel_crtc->base, primary,
-					NULL, &intel_crtc_funcs);
-	if (ret) {
-		drm_plane_cleanup(primary);
-		kfree(intel_crtc);
-		return;
-	}
+					cursor, &intel_crtc_funcs);
+	if (ret)
+		goto fail;
 
 	drm_mode_crtc_set_gamma_size(&intel_crtc->base, 256);
 	for (i = 0; i < 256; i++) {
@@ -11293,6 +11355,14 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
 	drm_crtc_helper_add(&intel_crtc->base, &intel_helper_funcs);
 
 	WARN_ON(drm_crtc_index(&intel_crtc->base) != intel_crtc->pipe);
+	return;
+
+fail:
+	if (primary)
+		drm_plane_cleanup(primary);
+	if (cursor)
+		drm_plane_cleanup(cursor);
+	kfree(intel_crtc);
 }
 
 enum pipe intel_get_pipe_from_connector(struct intel_connector *connector)

drivers/gpu/drm/i915/intel_drv.h

@@ -384,7 +384,6 @@ struct intel_crtc {
 
 	struct drm_i915_gem_object *cursor_bo;
 	uint32_t cursor_addr;
-	int16_t cursor_x, cursor_y;
 	int16_t cursor_width, cursor_height;
 	uint32_t cursor_cntl;
 	uint32_t cursor_base;