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1/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
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 union {
27 __u64 addr; /* pointer to buffer or iovecs */
28 __u64 splice_off_in;
29 };
30 __u32 len; /* buffer size or number of iovecs */
31 union {
32 __kernel_rwf_t rw_flags;
33 __u32 fsync_flags;
34 __u16 poll_events; /* compatibility */
35 __u32 poll32_events; /* word-reversed for BE */
36 __u32 sync_range_flags;
37 __u32 msg_flags;
38 __u32 timeout_flags;
39 __u32 accept_flags;
40 __u32 cancel_flags;
41 __u32 open_flags;
42 __u32 statx_flags;
43 __u32 fadvise_advice;
44 __u32 splice_flags;
45 };
46 __u64 user_data; /* data to be passed back at completion time */
47 union {
48 struct {
49 /* pack this to avoid bogus arm OABI complaints */
50 union {
51 /* index into fixed buffers, if used */
52 __u16 buf_index;
53 /* for grouped buffer selection */
54 __u16 buf_group;
55 } __attribute__((packed));
56 /* personality to use, if used */
57 __u16 personality;
58 __s32 splice_fd_in;
59 };
60 __u64 __pad2[3];
61 };
62};
63
64enum {
65 IOSQE_FIXED_FILE_BIT,
66 IOSQE_IO_DRAIN_BIT,
67 IOSQE_IO_LINK_BIT,
68 IOSQE_IO_HARDLINK_BIT,
69 IOSQE_ASYNC_BIT,
70 IOSQE_BUFFER_SELECT_BIT,
71};
72
73/*
74 * sqe->flags
75 */
76/* use fixed fileset */
77#define IOSQE_FIXED_FILE (1U << IOSQE_FIXED_FILE_BIT)
78/* issue after inflight IO */
79#define IOSQE_IO_DRAIN (1U << IOSQE_IO_DRAIN_BIT)
80/* links next sqe */
81#define IOSQE_IO_LINK (1U << IOSQE_IO_LINK_BIT)
82/* like LINK, but stronger */
83#define IOSQE_IO_HARDLINK (1U << IOSQE_IO_HARDLINK_BIT)
84/* always go async */
85#define IOSQE_ASYNC (1U << IOSQE_ASYNC_BIT)
86/* select buffer from sqe->buf_group */
87#define IOSQE_BUFFER_SELECT (1U << IOSQE_BUFFER_SELECT_BIT)
88
89/*
90 * io_uring_setup() flags
91 */
92#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
93#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
94#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
95#define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
96#define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */
97#define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
98
99enum {
100 IORING_OP_NOP,
101 IORING_OP_READV,
102 IORING_OP_WRITEV,
103 IORING_OP_FSYNC,
104 IORING_OP_READ_FIXED,
105 IORING_OP_WRITE_FIXED,
106 IORING_OP_POLL_ADD,
107 IORING_OP_POLL_REMOVE,
108 IORING_OP_SYNC_FILE_RANGE,
109 IORING_OP_SENDMSG,
110 IORING_OP_RECVMSG,
111 IORING_OP_TIMEOUT,
112 IORING_OP_TIMEOUT_REMOVE,
113 IORING_OP_ACCEPT,
114 IORING_OP_ASYNC_CANCEL,
115 IORING_OP_LINK_TIMEOUT,
116 IORING_OP_CONNECT,
117 IORING_OP_FALLOCATE,
118 IORING_OP_OPENAT,
119 IORING_OP_CLOSE,
120 IORING_OP_FILES_UPDATE,
121 IORING_OP_STATX,
122 IORING_OP_READ,
123 IORING_OP_WRITE,
124 IORING_OP_FADVISE,
125 IORING_OP_MADVISE,
126 IORING_OP_SEND,
127 IORING_OP_RECV,
128 IORING_OP_OPENAT2,
129 IORING_OP_EPOLL_CTL,
130 IORING_OP_SPLICE,
131 IORING_OP_PROVIDE_BUFFERS,
132 IORING_OP_REMOVE_BUFFERS,
133 IORING_OP_TEE,
134
135 /* this goes last, obviously */
136 IORING_OP_LAST,
137};
138
139/*
140 * sqe->fsync_flags
141 */
142#define IORING_FSYNC_DATASYNC (1U << 0)
143
144/*
145 * sqe->timeout_flags
146 */
147#define IORING_TIMEOUT_ABS (1U << 0)
148
149/*
150 * sqe->splice_flags
151 * extends splice(2) flags
152 */
153#define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
154
155/*
156 * IO completion data structure (Completion Queue Entry)
157 */
158struct io_uring_cqe {
159 __u64 user_data; /* sqe->data submission passed back */
160 __s32 res; /* result code for this event */
161 __u32 flags;
162};
163
164/*
165 * cqe->flags
166 *
167 * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
168 */
169#define IORING_CQE_F_BUFFER (1U << 0)
170
171enum {
172 IORING_CQE_BUFFER_SHIFT = 16,
173};
174
175/*
176 * Magic offsets for the application to mmap the data it needs
177 */
178#define IORING_OFF_SQ_RING 0ULL
179#define IORING_OFF_CQ_RING 0x8000000ULL
180#define IORING_OFF_SQES 0x10000000ULL
181
182/*
183 * Filled with the offset for mmap(2)
184 */
185struct io_sqring_offsets {
186 __u32 head;
187 __u32 tail;
188 __u32 ring_mask;
189 __u32 ring_entries;
190 __u32 flags;
191 __u32 dropped;
192 __u32 array;
193 __u32 resv1;
194 __u64 resv2;
195};
196
197/*
198 * sq_ring->flags
199 */
200#define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
201#define IORING_SQ_CQ_OVERFLOW (1U << 1) /* CQ ring is overflown */
202
203struct io_cqring_offsets {
204 __u32 head;
205 __u32 tail;
206 __u32 ring_mask;
207 __u32 ring_entries;
208 __u32 overflow;
209 __u32 cqes;
210 __u32 flags;
211 __u32 resv1;
212 __u64 resv2;
213};
214
215/*
216 * cq_ring->flags
217 */
218
219/* disable eventfd notifications */
220#define IORING_CQ_EVENTFD_DISABLED (1U << 0)
221
222/*
223 * io_uring_enter(2) flags
224 */
225#define IORING_ENTER_GETEVENTS (1U << 0)
226#define IORING_ENTER_SQ_WAKEUP (1U << 1)
227
228/*
229 * Passed in for io_uring_setup(2). Copied back with updated info on success
230 */
231struct io_uring_params {
232 __u32 sq_entries;
233 __u32 cq_entries;
234 __u32 flags;
235 __u32 sq_thread_cpu;
236 __u32 sq_thread_idle;
237 __u32 features;
238 __u32 wq_fd;
239 __u32 resv[3];
240 struct io_sqring_offsets sq_off;
241 struct io_cqring_offsets cq_off;
242};
243
244/*
245 * io_uring_params->features flags
246 */
247#define IORING_FEAT_SINGLE_MMAP (1U << 0)
248#define IORING_FEAT_NODROP (1U << 1)
249#define IORING_FEAT_SUBMIT_STABLE (1U << 2)
250#define IORING_FEAT_RW_CUR_POS (1U << 3)
251#define IORING_FEAT_CUR_PERSONALITY (1U << 4)
252#define IORING_FEAT_FAST_POLL (1U << 5)
253#define IORING_FEAT_POLL_32BITS (1U << 6)
254
255/*
256 * io_uring_register(2) opcodes and arguments
257 */
258#define IORING_REGISTER_BUFFERS 0
259#define IORING_UNREGISTER_BUFFERS 1
260#define IORING_REGISTER_FILES 2
261#define IORING_UNREGISTER_FILES 3
262#define IORING_REGISTER_EVENTFD 4
263#define IORING_UNREGISTER_EVENTFD 5
264#define IORING_REGISTER_FILES_UPDATE 6
265#define IORING_REGISTER_EVENTFD_ASYNC 7
266#define IORING_REGISTER_PROBE 8
267#define IORING_REGISTER_PERSONALITY 9
268#define IORING_UNREGISTER_PERSONALITY 10
269
270struct io_uring_files_update {
271 __u32 offset;
272 __u32 resv;
273 __aligned_u64 /* __s32 * */ fds;
274};
275
276#define IO_URING_OP_SUPPORTED (1U << 0)
277
278struct io_uring_probe_op {
279 __u8 op;
280 __u8 resv;
281 __u16 flags; /* IO_URING_OP_* flags */
282 __u32 resv2;
283};
284
285struct io_uring_probe {
286 __u8 last_op; /* last opcode supported */
287 __u8 ops_len; /* length of ops[] array below */
288 __u16 resv;
289 __u32 resv2[3];
290 struct io_uring_probe_op ops[0];
291};
292
293#endif