linux/drivers/virtio/virtio_dma_buf.c
Greg Kroah-Hartman 16b0314aa7 dma-buf: move dma-buf symbols into the DMA_BUF module namespace
In order to better track where in the kernel the dma-buf code is used,
put the symbols in the namespace DMA_BUF and modify all users of the
symbols to properly import the namespace to not break the build at the
same time.

Now the output of modinfo shows the use of these symbols, making it
easier to watch for users over time:

$ modinfo drivers/misc/fastrpc.ko | grep import
import_ns:      DMA_BUF

Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20211010124628.17691-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-25 14:53:08 +02:00

90 lines
2.2 KiB
C

// 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_LICENSE("GPL");
MODULE_IMPORT_NS(DMA_BUF);