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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 __u32 sync_range_flags;
30 __u32 msg_flags;
31 __u32 timeout_flags;
32 };
33 __u64 user_data; /* data to be passed back at completion time */
34 union {
35 __u16 buf_index; /* index into fixed buffers, if used */
36 __u64 __pad2[3];
37 };
38};
39
40/*
41 * sqe->flags
42 */
43#define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */
44#define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */
45#define IOSQE_IO_LINK (1U << 2) /* links next sqe */
46
47/*
48 * io_uring_setup() flags
49 */
50#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
51#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
52#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
53
54#define IORING_OP_NOP 0
55#define IORING_OP_READV 1
56#define IORING_OP_WRITEV 2
57#define IORING_OP_FSYNC 3
58#define IORING_OP_READ_FIXED 4
59#define IORING_OP_WRITE_FIXED 5
60#define IORING_OP_POLL_ADD 6
61#define IORING_OP_POLL_REMOVE 7
62#define IORING_OP_SYNC_FILE_RANGE 8
63#define IORING_OP_SENDMSG 9
64#define IORING_OP_RECVMSG 10
65#define IORING_OP_TIMEOUT 11
66
67/*
68 * sqe->fsync_flags
69 */
70#define IORING_FSYNC_DATASYNC (1U << 0)
71
72/*
73 * IO completion data structure (Completion Queue Entry)
74 */
75struct io_uring_cqe {
76 __u64 user_data; /* sqe->data submission passed back */
77 __s32 res; /* result code for this event */
78 __u32 flags;
79};
80
81/*
82 * Magic offsets for the application to mmap the data it needs
83 */
84#define IORING_OFF_SQ_RING 0ULL
85#define IORING_OFF_CQ_RING 0x8000000ULL
86#define IORING_OFF_SQES 0x10000000ULL
87
88/*
89 * Filled with the offset for mmap(2)
90 */
91struct io_sqring_offsets {
92 __u32 head;
93 __u32 tail;
94 __u32 ring_mask;
95 __u32 ring_entries;
96 __u32 flags;
97 __u32 dropped;
98 __u32 array;
99 __u32 resv1;
100 __u64 resv2;
101};
102
103/*
104 * sq_ring->flags
105 */
106#define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
107
108struct io_cqring_offsets {
109 __u32 head;
110 __u32 tail;
111 __u32 ring_mask;
112 __u32 ring_entries;
113 __u32 overflow;
114 __u32 cqes;
115 __u64 resv[2];
116};
117
118/*
119 * io_uring_enter(2) flags
120 */
121#define IORING_ENTER_GETEVENTS (1U << 0)
122#define IORING_ENTER_SQ_WAKEUP (1U << 1)
123
124/*
125 * Passed in for io_uring_setup(2). Copied back with updated info on success
126 */
127struct io_uring_params {
128 __u32 sq_entries;
129 __u32 cq_entries;
130 __u32 flags;
131 __u32 sq_thread_cpu;
132 __u32 sq_thread_idle;
133 __u32 features;
134 __u32 resv[4];
135 struct io_sqring_offsets sq_off;
136 struct io_cqring_offsets cq_off;
137};
138
139/*
140 * io_uring_params->features flags
141 */
142#define IORING_FEAT_SINGLE_MMAP (1U << 0)
143
144/*
145 * io_uring_register(2) opcodes and arguments
146 */
147#define IORING_REGISTER_BUFFERS 0
148#define IORING_UNREGISTER_BUFFERS 1
149#define IORING_REGISTER_FILES 2
150#define IORING_UNREGISTER_FILES 3
151#define IORING_REGISTER_EVENTFD 4
152#define IORING_UNREGISTER_EVENTFD 5
153
154#endif