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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 union {
23 __u64 off; /* offset into file */
24 __u64 addr2;
25 };
26 __u64 addr; /* pointer to buffer or iovecs */
27 __u32 len; /* buffer size or number of iovecs */
28 union {
29 __kernel_rwf_t rw_flags;
30 __u32 fsync_flags;
31 __u16 poll_events;
32 __u32 sync_range_flags;
33 __u32 msg_flags;
34 __u32 timeout_flags;
35 __u32 accept_flags;
36 __u32 cancel_flags;
37 };
38 __u64 user_data; /* data to be passed back at completion time */
39 union {
40 __u16 buf_index; /* index into fixed buffers, if used */
41 __u64 __pad2[3];
42 };
43};
44
45/*
46 * sqe->flags
47 */
48#define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */
49#define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */
50#define IOSQE_IO_LINK (1U << 2) /* links next sqe */
51#define IOSQE_IO_HARDLINK (1U << 3) /* like LINK, but stronger */
52
53/*
54 * io_uring_setup() flags
55 */
56#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
57#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
58#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
59#define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
60
61enum {
62 IORING_OP_NOP,
63 IORING_OP_READV,
64 IORING_OP_WRITEV,
65 IORING_OP_FSYNC,
66 IORING_OP_READ_FIXED,
67 IORING_OP_WRITE_FIXED,
68 IORING_OP_POLL_ADD,
69 IORING_OP_POLL_REMOVE,
70 IORING_OP_SYNC_FILE_RANGE,
71 IORING_OP_SENDMSG,
72 IORING_OP_RECVMSG,
73 IORING_OP_TIMEOUT,
74 IORING_OP_TIMEOUT_REMOVE,
75 IORING_OP_ACCEPT,
76 IORING_OP_ASYNC_CANCEL,
77 IORING_OP_LINK_TIMEOUT,
78 IORING_OP_CONNECT,
79
80 /* this goes last, obviously */
81 IORING_OP_LAST,
82};
83
84/*
85 * sqe->fsync_flags
86 */
87#define IORING_FSYNC_DATASYNC (1U << 0)
88
89/*
90 * sqe->timeout_flags
91 */
92#define IORING_TIMEOUT_ABS (1U << 0)
93
94/*
95 * IO completion data structure (Completion Queue Entry)
96 */
97struct io_uring_cqe {
98 __u64 user_data; /* sqe->data submission passed back */
99 __s32 res; /* result code for this event */
100 __u32 flags;
101};
102
103/*
104 * Magic offsets for the application to mmap the data it needs
105 */
106#define IORING_OFF_SQ_RING 0ULL
107#define IORING_OFF_CQ_RING 0x8000000ULL
108#define IORING_OFF_SQES 0x10000000ULL
109
110/*
111 * Filled with the offset for mmap(2)
112 */
113struct io_sqring_offsets {
114 __u32 head;
115 __u32 tail;
116 __u32 ring_mask;
117 __u32 ring_entries;
118 __u32 flags;
119 __u32 dropped;
120 __u32 array;
121 __u32 resv1;
122 __u64 resv2;
123};
124
125/*
126 * sq_ring->flags
127 */
128#define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
129
130struct io_cqring_offsets {
131 __u32 head;
132 __u32 tail;
133 __u32 ring_mask;
134 __u32 ring_entries;
135 __u32 overflow;
136 __u32 cqes;
137 __u64 resv[2];
138};
139
140/*
141 * io_uring_enter(2) flags
142 */
143#define IORING_ENTER_GETEVENTS (1U << 0)
144#define IORING_ENTER_SQ_WAKEUP (1U << 1)
145
146/*
147 * Passed in for io_uring_setup(2). Copied back with updated info on success
148 */
149struct io_uring_params {
150 __u32 sq_entries;
151 __u32 cq_entries;
152 __u32 flags;
153 __u32 sq_thread_cpu;
154 __u32 sq_thread_idle;
155 __u32 features;
156 __u32 resv[4];
157 struct io_sqring_offsets sq_off;
158 struct io_cqring_offsets cq_off;
159};
160
161/*
162 * io_uring_params->features flags
163 */
164#define IORING_FEAT_SINGLE_MMAP (1U << 0)
165#define IORING_FEAT_NODROP (1U << 1)
166#define IORING_FEAT_SUBMIT_STABLE (1U << 2)
167
168/*
169 * io_uring_register(2) opcodes and arguments
170 */
171#define IORING_REGISTER_BUFFERS 0
172#define IORING_UNREGISTER_BUFFERS 1
173#define IORING_REGISTER_FILES 2
174#define IORING_UNREGISTER_FILES 3
175#define IORING_REGISTER_EVENTFD 4
176#define IORING_UNREGISTER_EVENTFD 5
177#define IORING_REGISTER_FILES_UPDATE 6
178
179struct io_uring_files_update {
180 __u32 offset;
181 __u32 resv;
182 __aligned_u64 /* __s32 * */ fds;
183};
184
185#endif