drm/mode: Add user blob-creation ioctl

Add an ioctl which allows users to create blob properties from supplied
data. Currently this only supports modes, creating a drm_display_mode from
the userspace drm_mode_modeinfo.

v2: Removed size/type checks.
    Rebased on new patches to allow error propagation from create_blob,
    as well as avoiding double-allocation.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@intel.com>
Tested-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index ff6ef62..3801584 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -786,6 +786,8 @@
 #define DRM_IOCTL_MODE_OBJ_SETPROPERTY	DRM_IOWR(0xBA, struct drm_mode_obj_set_property)
 #define DRM_IOCTL_MODE_CURSOR2		DRM_IOWR(0xBB, struct drm_mode_cursor2)
 #define DRM_IOCTL_MODE_ATOMIC		DRM_IOWR(0xBC, struct drm_mode_atomic)
+#define DRM_IOCTL_MODE_CREATEPROPBLOB	DRM_IOWR(0xBD, struct drm_mode_create_blob)
+#define DRM_IOCTL_MODE_DESTROYPROPBLOB	DRM_IOWR(0xBE, struct drm_mode_destroy_blob)
 
 /**
  * Device specific ioctls should only be in their respective headers