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