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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * dma-bufs for virtio exported objects4 *5 * Copyright (C) 2020 Google, Inc.6 */7 8#include <linux/module.h>9#include <linux/virtio_dma_buf.h>10 11/**12 * virtio_dma_buf_export - Creates a new dma-buf for a virtio exported object13 * @exp_info: [in] see dma_buf_export(). ops MUST refer to a dma_buf_ops14 * struct embedded in a virtio_dma_buf_ops.15 *16 * This wraps dma_buf_export() to allow virtio drivers to create a dma-buf17 * for an virtio exported object that can be queried by other virtio drivers18 * for the object's UUID.19 */20struct dma_buf *virtio_dma_buf_export21 (const struct dma_buf_export_info *exp_info)22{23 const struct virtio_dma_buf_ops *virtio_ops =24 container_of(exp_info->ops,25 const struct virtio_dma_buf_ops, ops);26 27 if (!exp_info->ops ||28 exp_info->ops->attach != &virtio_dma_buf_attach ||29 !virtio_ops->get_uuid) {30 return ERR_PTR(-EINVAL);31 }32 33 return dma_buf_export(exp_info);34}35EXPORT_SYMBOL(virtio_dma_buf_export);36 37/**38 * virtio_dma_buf_attach - mandatory attach callback for virtio dma-bufs39 */40int virtio_dma_buf_attach(struct dma_buf *dma_buf,41 struct dma_buf_attachment *attach)42{43 int ret;44 const struct virtio_dma_buf_ops *ops =45 container_of(dma_buf->ops,46 const struct virtio_dma_buf_ops, ops);47 48 if (ops->device_attach) {49 ret = ops->device_attach(dma_buf, attach);50 if (ret)51 return ret;52 }53 return 0;54}55EXPORT_SYMBOL(virtio_dma_buf_attach);56 57/**58 * is_virtio_dma_buf - returns true if the given dma-buf is a virtio dma-buf59 * @dma_buf: buffer to query60 */61bool is_virtio_dma_buf(struct dma_buf *dma_buf)62{63 return dma_buf->ops->attach == &virtio_dma_buf_attach;64}65EXPORT_SYMBOL(is_virtio_dma_buf);66 67/**68 * virtio_dma_buf_get_uuid - gets a virtio dma-buf's exported object's uuid69 * @dma_buf: [in] buffer to query70 * @uuid: [out] the uuid71 *72 * Returns: 0 on success, negative on failure.73 */74int virtio_dma_buf_get_uuid(struct dma_buf *dma_buf,75 uuid_t *uuid)76{77 const struct virtio_dma_buf_ops *ops =78 container_of(dma_buf->ops,79 const struct virtio_dma_buf_ops, ops);80 81 if (!is_virtio_dma_buf(dma_buf))82 return -EINVAL;83 84 return ops->get_uuid(dma_buf, uuid);85}86EXPORT_SYMBOL(virtio_dma_buf_get_uuid);87 88MODULE_DESCRIPTION("dma-bufs for virtio exported objects");89MODULE_LICENSE("GPL");90MODULE_IMPORT_NS(DMA_BUF);91