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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - drivers/virtio/virtio_dma_buf.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * dma-bufs for virtio exported objects
5 * Copyright (C) 2020 Google, Inc.
8 #include <linux/module.h>
9 #include <linux/virtio_dma_buf.h>
12 * virtio_dma_buf_export - Creates a new dma-buf for a virtio exported object
13 * @exp_info: [in] see dma_buf_export(). ops MUST refer to a dma_buf_ops
14 * struct embedded in a virtio_dma_buf_ops.
16 * This wraps dma_buf_export() to allow virtio drivers to create a dma-buf
17 * for an virtio exported object that can be queried by other virtio drivers
18 * for the object's UUID.
20 struct dma_buf
*virtio_dma_buf_export
21 (const struct dma_buf_export_info
*exp_info
)
23 const struct virtio_dma_buf_ops
*virtio_ops
=
24 container_of(exp_info
->ops
,
25 const struct virtio_dma_buf_ops
, ops
);
28 exp_info
->ops
->attach
!= &virtio_dma_buf_attach
||
29 !virtio_ops
->get_uuid
) {
30 return ERR_PTR(-EINVAL
);
33 return dma_buf_export(exp_info
);
35 EXPORT_SYMBOL(virtio_dma_buf_export
);
38 * virtio_dma_buf_attach - mandatory attach callback for virtio dma-bufs
40 int virtio_dma_buf_attach(struct dma_buf
*dma_buf
,
41 struct dma_buf_attachment
*attach
)
44 const struct virtio_dma_buf_ops
*ops
=
45 container_of(dma_buf
->ops
,
46 const struct virtio_dma_buf_ops
, ops
);
48 if (ops
->device_attach
) {
49 ret
= ops
->device_attach(dma_buf
, attach
);
55 EXPORT_SYMBOL(virtio_dma_buf_attach
);
58 * is_virtio_dma_buf - returns true if the given dma-buf is a virtio dma-buf
59 * @dma_buf: buffer to query
61 bool is_virtio_dma_buf(struct dma_buf
*dma_buf
)
63 return dma_buf
->ops
->attach
== &virtio_dma_buf_attach
;
65 EXPORT_SYMBOL(is_virtio_dma_buf
);
68 * virtio_dma_buf_get_uuid - gets a virtio dma-buf's exported object's uuid
69 * @dma_buf: [in] buffer to query
70 * @uuid: [out] the uuid
72 * Returns: 0 on success, negative on failure.
74 int virtio_dma_buf_get_uuid(struct dma_buf
*dma_buf
,
77 const struct virtio_dma_buf_ops
*ops
=
78 container_of(dma_buf
->ops
,
79 const struct virtio_dma_buf_ops
, ops
);
81 if (!is_virtio_dma_buf(dma_buf
))
84 return ops
->get_uuid(dma_buf
, uuid
);
86 EXPORT_SYMBOL(virtio_dma_buf_get_uuid
);
88 MODULE_LICENSE("GPL");