drm/i915: check gem bo size when creating framebuffers

It's better to catch such fallout early, and this way we can rely on
the checking done by the drm core on fb->heigh/width at modeset time.

If we ever support planar formats on intel we might want to look into
a common helper to do all this, but for now this is good enough.

v2: Take tiling into account, requested by Ville.

v3: Fix tile height on gen2, spotted by Ville.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Requested-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -9991,6 +9991,7 @@ int intel_framebuffer_init(struct drm_device *dev,
 			   struct drm_mode_fb_cmd2 *mode_cmd,
 			   struct drm_i915_gem_object *obj)
 {
+	int aligned_height, tile_height;
 	int pitch_limit;
 	int ret;
 
@@ -10084,6 +10085,13 @@ int intel_framebuffer_init(struct drm_device *dev,
 	if (mode_cmd->offsets[0] != 0)
 		return -EINVAL;
 
+	tile_height = IS_GEN2(dev) ? 16 : 8;
+	aligned_height = ALIGN(mode_cmd->height,
+			       obj->tiling_mode ? tile_height : 1);
+	/* FIXME drm helper for size checks (especially planar formats)? */
+	if (obj->base.size < aligned_height * mode_cmd->pitches[0])
+		return -EINVAL;
+
 	drm_helper_mode_fill_fb_struct(&intel_fb->base, mode_cmd);
 	intel_fb->obj = obj;
 	intel_fb->obj->framebuffer_references++;