drm/i915: Tighten the exposure ARGB/ABGR 8888 formats

ARGB8888 is used for cursors on all platforms so we need to allow it
everywhere.

ABGR8888 is currently only honoured:
  - on VLV/CHV in sprite planes
  - on SKL+ for primary and sprite planes
so only allow it for those platforms.

Note that we only support ARGB8888/ABGR8888 on the primary plane for
SKL/BXT because we have in line of sight the pipe bottom color on those
platforms and because the primary plane programming on VLV/CHV doesn't
anything different for those formats today.

v2: Fix the logic to forbid the creation ABGR2101010 fbs (Ville)
v3: Still allow the creation of ARGB8888 fbs now that cursor planes use
    real fb objects (found by PRTS).

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -51,11 +51,19 @@ static const uint32_t i8xx_primary_formats[] = {
 	DRM_FORMAT_RGB565,
 	DRM_FORMAT_XRGB1555,
 	DRM_FORMAT_XRGB8888,
-	DRM_FORMAT_ARGB8888,
 };
 
 /* Primary plane formats for gen >= 4 */
 static const uint32_t i965_primary_formats[] = {
+	DRM_FORMAT_C8,
+	DRM_FORMAT_RGB565,
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_XBGR8888,
+	DRM_FORMAT_XRGB2101010,
+	DRM_FORMAT_XBGR2101010,
+};
+
+static const uint32_t skl_primary_formats[] = {
 	DRM_FORMAT_C8,
 	DRM_FORMAT_RGB565,
 	DRM_FORMAT_XRGB8888,
@@ -2704,11 +2712,9 @@ static void i9xx_update_primary_plane(struct drm_crtc *crtc,
 		dspcntr |= DISPPLANE_BGRX565;
 		break;
 	case DRM_FORMAT_XRGB8888:
-	case DRM_FORMAT_ARGB8888:
 		dspcntr |= DISPPLANE_BGRX888;
 		break;
 	case DRM_FORMAT_XBGR8888:
-	case DRM_FORMAT_ABGR8888:
 		dspcntr |= DISPPLANE_RGBX888;
 		break;
 	case DRM_FORMAT_XRGB2101010:
@@ -2810,11 +2816,9 @@ static void ironlake_update_primary_plane(struct drm_crtc *crtc,
 		dspcntr |= DISPPLANE_BGRX565;
 		break;
 	case DRM_FORMAT_XRGB8888:
-	case DRM_FORMAT_ARGB8888:
 		dspcntr |= DISPPLANE_BGRX888;
 		break;
 	case DRM_FORMAT_XBGR8888:
-	case DRM_FORMAT_ABGR8888:
 		dspcntr |= DISPPLANE_RGBX888;
 		break;
 	case DRM_FORMAT_XRGB2101010:
@@ -13293,12 +13297,15 @@ static struct drm_plane *intel_primary_plane_create(struct drm_device *dev,
 	if (HAS_FBC(dev) && INTEL_INFO(dev)->gen < 4)
 		primary->plane = !pipe;
 
-	if (INTEL_INFO(dev)->gen <= 3) {
-		intel_primary_formats = i8xx_primary_formats;
-		num_formats = ARRAY_SIZE(i8xx_primary_formats);
-	} else {
+	if (INTEL_INFO(dev)->gen >= 9) {
+		intel_primary_formats = skl_primary_formats;
+		num_formats = ARRAY_SIZE(skl_primary_formats);
+	} else if (INTEL_INFO(dev)->gen >= 4) {
 		intel_primary_formats = i965_primary_formats;
 		num_formats = ARRAY_SIZE(i965_primary_formats);
+	} else {
+		intel_primary_formats = i8xx_primary_formats;
+		num_formats = ARRAY_SIZE(i8xx_primary_formats);
 	}
 
 	drm_universal_plane_init(dev, &primary->base, 0,
@@ -13985,8 +13992,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
 			return -EINVAL;
 		}
 		break;
-	case DRM_FORMAT_XBGR8888:
 	case DRM_FORMAT_ABGR8888:
+		if (!IS_VALLEYVIEW(dev) && INTEL_INFO(dev)->gen < 9) {
+			DRM_DEBUG("unsupported pixel format: %s\n",
+				  drm_get_format_name(mode_cmd->pixel_format));
+			return -EINVAL;
+		}
+		break;
+	case DRM_FORMAT_XBGR8888:
 	case DRM_FORMAT_XRGB2101010:
 	case DRM_FORMAT_XBGR2101010:
 		if (INTEL_INFO(dev)->gen < 4) {