drm: Use a normal idr allocation for the obj->name

Unlike the handle, the name table uses a sleeping mutex rather than a
spinlock. The allocation is in a normal context, and we can use the
simpler sleeping gfp_t, rather than have to take from the atomic
reserves.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451902261-25380-3-git-send-email-chris@chris-wilson.co.ukSigned-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_gem.c

@@ -642,7 +642,6 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 		return -ENOENT;
 
 	mutex_lock(&dev->object_name_lock);
-	idr_preload(GFP_KERNEL);
 	/* prevent races with concurrent gem_close. */
 	if (obj->handle_count == 0) {
 		ret = -ENOENT;
@@ -650,7 +649,7 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 	}
 
 	if (!obj->name) {
-		ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT);
+		ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL);
 		if (ret < 0)
 			goto err;
 
@@ -661,7 +660,6 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 	ret = 0;
 
 err:
-	idr_preload_end();
 	mutex_unlock(&dev->object_name_lock);
 	drm_gem_object_unreference_unlocked(obj);
 	return ret;