drm/i915: WARN if plane src coords are too big

Inform us if we're buggy and are about to exceed the size of the
bitfields in the plane TILEOFF/OFFSET registers.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111163711.12913-2-ville.syrjala@linux.intel.com
Reviewed-by: Karthik B S <karthik.b.s@intel.com>

drivers/gpu/drm/i915/display/i9xx_plane.c

@@ -276,6 +276,13 @@ int i9xx_check_plane_surface(struct intel_plane_state *plane_state)
 		}
 	}
 
+	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
+		drm_WARN_ON(&dev_priv->drm, src_x > 8191 || src_y > 4095);
+	} else if (INTEL_GEN(dev_priv) >= 4 &&
+		   fb->modifier == I915_FORMAT_MOD_X_TILED) {
+		drm_WARN_ON(&dev_priv->drm, src_x > 4095 || src_y > 4095);
+	}
+
 	plane_state->color_plane[0].offset = offset;
 	plane_state->color_plane[0].x = src_x;
 	plane_state->color_plane[0].y = src_y;

drivers/gpu/drm/i915/display/intel_display.c

@@ -3089,6 +3089,8 @@ static int skl_check_main_surface(struct intel_plane_state *plane_state)
 		}
 	}
 
+	drm_WARN_ON(&dev_priv->drm, x > 8191 || y > 8191);
+
 	plane_state->color_plane[0].offset = offset;
 	plane_state->color_plane[0].x = x;
 	plane_state->color_plane[0].y = y;
@@ -3161,6 +3163,8 @@ static int skl_check_nv12_aux_surface(struct intel_plane_state *plane_state)
 		}
 	}
 
+	drm_WARN_ON(&i915->drm, x > 8191 || y > 8191);
+
 	plane_state->color_plane[uv_plane].offset = offset;
 	plane_state->color_plane[uv_plane].x = x;
 	plane_state->color_plane[uv_plane].y = y;