struct dma_buf_map ptr; int ret = 0; dma_buf_map_clear(map); if (WARN_ON(!dmabuf)) return NULL; return -EINVAL; if (!dmabuf->ops->vmap) return NULL; return -EINVAL; mutex_lock(&dmabuf->lock); if (dmabuf->vmapping_counter) { dmabuf->vmapping_counter++; BUG_ON(dma_bu...