drm/i915: Extract intel_cursor_check_surface()

Extract intel_cursor_check_surface() to better match the code layout
of the other plane types.

Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-14-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -9678,13 +9678,37 @@ static bool intel_cursor_size_ok(const struct intel_plane_state *plane_state)
 		height > 0 && height <= config->cursor_height;
 }
 
-static int intel_check_cursor(struct intel_crtc_state *crtc_state,
-			      struct intel_plane_state *plane_state)
+static int intel_cursor_check_surface(struct intel_plane_state *plane_state)
 {
 	const struct drm_framebuffer *fb = plane_state->base.fb;
 	unsigned int rotation = plane_state->base.rotation;
 	int src_x, src_y;
 	u32 offset;
+
+	intel_fill_fb_ggtt_view(&plane_state->view, fb, rotation);
+	plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0, rotation);
+
+	src_x = plane_state->base.src_x >> 16;
+	src_y = plane_state->base.src_y >> 16;
+
+	intel_add_fb_offsets(&src_x, &src_y, plane_state, 0);
+	offset = intel_plane_compute_aligned_offset(&src_x, &src_y,
+						    plane_state, 0);
+
+	if (src_x != 0 || src_y != 0) {
+		DRM_DEBUG_KMS("Arbitrary cursor panning not supported\n");
+		return -EINVAL;
+	}
+
+	plane_state->color_plane[0].offset = offset;
+
+	return 0;
+}
+
+static int intel_check_cursor(struct intel_crtc_state *crtc_state,
+			      struct intel_plane_state *plane_state)
+{
+	const struct drm_framebuffer *fb = plane_state->base.fb;
 	int ret;
 
 	if (fb && fb->modifier != DRM_FORMAT_MOD_LINEAR) {
@@ -9707,22 +9731,9 @@ static int intel_check_cursor(struct intel_crtc_state *crtc_state,
 	if (ret)
 		return ret;
 
-	intel_fill_fb_ggtt_view(&plane_state->view, fb, rotation);
-	plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0, rotation);
-
-	src_x = plane_state->base.src_x >> 16;
-	src_y = plane_state->base.src_y >> 16;
-
-	intel_add_fb_offsets(&src_x, &src_y, plane_state, 0);
-	offset = intel_plane_compute_aligned_offset(&src_x, &src_y,
-						    plane_state, 0);
-
-	if (src_x != 0 || src_y != 0) {
-		DRM_DEBUG_KMS("Arbitrary cursor panning not supported\n");
-		return -EINVAL;
-	}
-
-	plane_state->color_plane[0].offset = offset;
+	ret = intel_cursor_check_surface(plane_state);
+	if (ret)
+		return ret;
 
 	return 0;
 }