ww_mutex_lock
ww_mutex_lock(&resv->lock, NULL);
ret = ww_mutex_lock(&lock->mutex, &ctx->ww_ctx);
ww_mutex_lock(&lock->mutex, NULL);
ret = ww_mutex_lock(&bo->resv->lock, ticket);
return ww_mutex_lock(&obj->lock, ctx);
extern int ww_mutex_lock(struct ww_mutex *ww, struct ww_acquire_ctx *ctx);
ww_mutex_lock(&resv->lock, NULL);