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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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678f6e28b5
Add an interface for the user to notify the kernel that it is done reading the devmem dmabuf frags returned as cmsg. The kernel will drop the reference on the frags to make them available for reuse. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240910171458.219195-11-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
50 lines
1.2 KiB
C
50 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
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/*
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* Berkeley style UIO structures - Alan Cox 1994.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _UAPI__LINUX_UIO_H
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#define _UAPI__LINUX_UIO_H
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#include <linux/compiler.h>
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#include <linux/types.h>
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struct iovec
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{
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void __user *iov_base; /* BSD uses caddr_t (1003.1g requires void *) */
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__kernel_size_t iov_len; /* Must be size_t (1003.1g) */
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};
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struct dmabuf_cmsg {
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__u64 frag_offset; /* offset into the dmabuf where the frag starts.
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*/
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__u32 frag_size; /* size of the frag. */
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__u32 frag_token; /* token representing this frag for
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* DEVMEM_DONTNEED.
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*/
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__u32 dmabuf_id; /* dmabuf id this frag belongs to. */
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__u32 flags; /* Currently unused. Reserved for future
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* uses.
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*/
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};
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struct dmabuf_token {
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__u32 token_start;
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__u32 token_count;
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};
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/*
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* UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
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*/
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#define UIO_FASTIOV 8
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#define UIO_MAXIOV 1024
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#endif /* _UAPI__LINUX_UIO_H */
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