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