53 lines
1.6 KiB
C
53 lines
1.6 KiB
C
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/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* WrapFD kernel API
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*
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* Copyright (C) 2025 Google, Inc.
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*/
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#ifndef _LINUX_WRAPFD_H
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#define _LINUX_WRAPFD_H
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union wrapfd_mappable {
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struct dma_buf *dmabuf;
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};
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/*
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* Get mappable object. Caller also gets buffer ownership.
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* Function does not take file references, therefore the caller should
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* ensure the file is stable until wrapfd_put() is called.
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*
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* file: wrap file to get the folios from.
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* dev: device requesting the object and the ownership.
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*
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* On success returns mappable object. On error returns:
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* -EBADF: file is invalid.
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* -ENODEV: device is invalid.
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* -EINVAL: buffer is mapped.
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* -EBUSY: buffer is owned by another device.
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* -ENOENT: wrap is empty (buffer got freed or moved)
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*/
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int wrapfd_get(struct file *file, struct device *dev,
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union wrapfd_mappable *mappable);
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/*
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* Release mappable object and buffer ownership. Caller should own the buffer.
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* Note that the caller might still keep the buffer mapped. If the buffer
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* is reused or freed then the next wrapfd_get() call will fail with -ENOENT
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* and the mapping should be invalidated. If wrapfd_get() succeeds then
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* previous mappings are still valid and can be reused.
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*
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* file: wrap file to release ownership for.
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* dev: device requesting the operation.
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* mappable: mappable object returned by wrapfd_get().
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*
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* On success returns 0. On error returns:
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* -EBADF: file is invalid.
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* -ENODEV: device is invalid.
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* -EBUSY: buffer is not owned by the caller.
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*/
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int wrapfd_put(struct file *file, struct device *dev,
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union wrapfd_mappable *mappable);
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#endif /* _LINUX_WRAPFD_H */
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