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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * Header file for the io_uring interface.
4 *
5 * Copyright (C) 2019 Jens Axboe
6 * Copyright (C) 2019 Christoph Hellwig
7 */
8#ifndef LINUX_IO_URING_H
9#define LINUX_IO_URING_H
10
11#include <linux/fs.h>
12#include <linux/types.h>
13
14/*
15 * IO submission data structure (Submission Queue Entry)
16 */
17struct io_uring_sqe {
18 __u8 opcode; /* type of operation for this sqe */
19 __u8 flags; /* IOSQE_ flags */
20 __u16 ioprio; /* ioprio for the request */
21 __s32 fd; /* file descriptor to do IO on */
22 __u64 off; /* offset into file */
23 __u64 addr; /* pointer to buffer or iovecs */
24 __u32 len; /* buffer size or number of iovecs */
25 union {
26 __kernel_rwf_t rw_flags;
27 __u32 fsync_flags;
28 __u16 poll_events;
29 };
30 __u64 user_data; /* data to be passed back at completion time */
31 union {
32 __u16 buf_index; /* index into fixed buffers, if used */
33 __u64 __pad2[3];
34 };
35};
36
37/*
38 * sqe->flags
39 */
40#define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */
41
42/*
43 * io_uring_setup() flags
44 */
45#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
46#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
47#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
48
49#define IORING_OP_NOP 0
50#define IORING_OP_READV 1
51#define IORING_OP_WRITEV 2
52#define IORING_OP_FSYNC 3
53#define IORING_OP_READ_FIXED 4
54#define IORING_OP_WRITE_FIXED 5
55#define IORING_OP_POLL_ADD 6
56#define IORING_OP_POLL_REMOVE 7
57
58/*
59 * sqe->fsync_flags
60 */
61#define IORING_FSYNC_DATASYNC (1U << 0)
62
63/*
64 * IO completion data structure (Completion Queue Entry)
65 */
66struct io_uring_cqe {
67 __u64 user_data; /* sqe->data submission passed back */
68 __s32 res; /* result code for this event */
69 __u32 flags;
70};
71
72/*
73 * Magic offsets for the application to mmap the data it needs
74 */
75#define IORING_OFF_SQ_RING 0ULL
76#define IORING_OFF_CQ_RING 0x8000000ULL
77#define IORING_OFF_SQES 0x10000000ULL
78
79/*
80 * Filled with the offset for mmap(2)
81 */
82struct io_sqring_offsets {
83 __u32 head;
84 __u32 tail;
85 __u32 ring_mask;
86 __u32 ring_entries;
87 __u32 flags;
88 __u32 dropped;
89 __u32 array;
90 __u32 resv1;
91 __u64 resv2;
92};
93
94/*
95 * sq_ring->flags
96 */
97#define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
98
99struct io_cqring_offsets {
100 __u32 head;
101 __u32 tail;
102 __u32 ring_mask;
103 __u32 ring_entries;
104 __u32 overflow;
105 __u32 cqes;
106 __u64 resv[2];
107};
108
109/*
110 * io_uring_enter(2) flags
111 */
112#define IORING_ENTER_GETEVENTS (1U << 0)
113#define IORING_ENTER_SQ_WAKEUP (1U << 1)
114
115/*
116 * Passed in for io_uring_setup(2). Copied back with updated info on success
117 */
118struct io_uring_params {
119 __u32 sq_entries;
120 __u32 cq_entries;
121 __u32 flags;
122 __u32 sq_thread_cpu;
123 __u32 sq_thread_idle;
124 __u32 resv[5];
125 struct io_sqring_offsets sq_off;
126 struct io_cqring_offsets cq_off;
127};
128
129/*
130 * io_uring_register(2) opcodes and arguments
131 */
132#define IORING_REGISTER_BUFFERS 0
133#define IORING_UNREGISTER_BUFFERS 1
134#define IORING_REGISTER_FILES 2
135#define IORING_UNREGISTER_FILES 3
136
137#endif