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// 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");
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