// SPDX-License-Identifier: GPL-2.0-or-later /* * dma-bufs for virtio exported objects * * Copyright (C) 2020 Google, Inc. */ #include <linux/module.h> #include <linux/virtio_dma_buf.h> /** * virtio_dma_buf_export - Creates a new dma-buf for a virtio exported object * @exp_info: [in] see dma_buf_export(). ops MUST refer to a dma_buf_ops * struct embedded in a virtio_dma_buf_ops. * * This wraps dma_buf_export() to allow virtio drivers to create a dma-buf * for an virtio exported object that can be queried by other virtio drivers * for the object's UUID. */ struct dma_buf *virtio_dma_buf_export (const struct dma_buf_export_info *exp_info) { const struct virtio_dma_buf_ops *virtio_ops = container_of(exp_info->ops, const struct virtio_dma_buf_ops, ops); if (!exp_info->ops || exp_info->ops->attach != &virtio_dma_buf_attach || !virtio_ops->get_uuid) { return ERR_PTR(-EINVAL); } return dma_buf_export(exp_info); } EXPORT_SYMBOL(virtio_dma_buf_export); /** * virtio_dma_buf_attach - mandatory attach callback for virtio dma-bufs */ int virtio_dma_buf_attach(struct dma_buf *dma_buf, struct dma_buf_attachment *attach) { int ret; const struct virtio_dma_buf_ops *ops = container_of(dma_buf->ops, const struct virtio_dma_buf_ops, ops); if (ops->device_attach) { ret = ops->device_attach(dma_buf, attach); if (ret) return ret; } return 0; } EXPORT_SYMBOL(virtio_dma_buf_attach); /** * is_virtio_dma_buf - returns true if the given dma-buf is a virtio dma-buf * @dma_buf: buffer to query */ bool is_virtio_dma_buf(struct dma_buf *dma_buf) { return dma_buf->ops->attach == &virtio_dma_buf_attach; } EXPORT_SYMBOL(is_virtio_dma_buf); /** * virtio_dma_buf_get_uuid - gets a virtio dma-buf's exported object's uuid * @dma_buf: [in] buffer to query * @uuid: [out] the uuid * * Returns: 0 on success, negative on failure. */ int virtio_dma_buf_get_uuid(struct dma_buf *dma_buf, uuid_t *uuid) { const struct virtio_dma_buf_ops *ops = container_of(dma_buf->ops, const struct virtio_dma_buf_ops, ops); if (!is_virtio_dma_buf(dma_buf)) return -EINVAL; return ops->get_uuid(dma_buf, uuid); } EXPORT_SYMBOL(virtio_dma_buf_get_uuid); MODULE_DESCRIPTION("dma-bufs for virtio exported objects"); MODULE_LICENSE("GPL"); MODULE_IMPORT_NS(DMA_BUF);