1 /* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
3 * Header file for the io_uring interface.
5 * Copyright (C) 2019 Jens Axboe
6 * Copyright (C) 2019 Christoph Hellwig
8 #ifndef LINUX_IO_URING_H
9 #define LINUX_IO_URING_H
12 #include <linux/types.h>
15 * IO submission data structure (Submission Queue Entry)
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 */
23 __u64 off; /* offset into file */
27 __u64 addr; /* pointer to buffer or iovecs */
30 __u32 len; /* buffer size or number of iovecs */
32 __kernel_rwf_t rw_flags;
34 __u16 poll_events; /* compatibility */
35 __u32 poll32_events; /* word-reversed for BE */
36 __u32 sync_range_flags;
46 __u64 user_data; /* data to be passed back at completion time */
49 /* pack this to avoid bogus arm OABI complaints */
51 /* index into fixed buffers, if used */
53 /* for grouped buffer selection */
55 } __attribute__((packed));
56 /* personality to use, if used */
68 IOSQE_IO_HARDLINK_BIT,
70 IOSQE_BUFFER_SELECT_BIT,
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)
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)
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)
90 * io_uring_setup() flags
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 */
104 IORING_OP_READ_FIXED,
105 IORING_OP_WRITE_FIXED,
107 IORING_OP_POLL_REMOVE,
108 IORING_OP_SYNC_FILE_RANGE,
112 IORING_OP_TIMEOUT_REMOVE,
114 IORING_OP_ASYNC_CANCEL,
115 IORING_OP_LINK_TIMEOUT,
120 IORING_OP_FILES_UPDATE,
131 IORING_OP_PROVIDE_BUFFERS,
132 IORING_OP_REMOVE_BUFFERS,
135 /* this goes last, obviously */
142 #define IORING_FSYNC_DATASYNC (1U << 0)
147 #define IORING_TIMEOUT_ABS (1U << 0)
151 * extends splice(2) flags
153 #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
156 * IO completion data structure (Completion Queue Entry)
158 struct io_uring_cqe {
159 __u64 user_data; /* sqe->data submission passed back */
160 __s32 res; /* result code for this event */
167 * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
169 #define IORING_CQE_F_BUFFER (1U << 0)
172 IORING_CQE_BUFFER_SHIFT = 16,
176 * Magic offsets for the application to mmap the data it needs
178 #define IORING_OFF_SQ_RING 0ULL
179 #define IORING_OFF_CQ_RING 0x8000000ULL
180 #define IORING_OFF_SQES 0x10000000ULL
183 * Filled with the offset for mmap(2)
185 struct io_sqring_offsets {
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 */
203 struct io_cqring_offsets {
219 /* disable eventfd notifications */
220 #define IORING_CQ_EVENTFD_DISABLED (1U << 0)
223 * io_uring_enter(2) flags
225 #define IORING_ENTER_GETEVENTS (1U << 0)
226 #define IORING_ENTER_SQ_WAKEUP (1U << 1)
229 * Passed in for io_uring_setup(2). Copied back with updated info on success
231 struct io_uring_params {
236 __u32 sq_thread_idle;
240 struct io_sqring_offsets sq_off;
241 struct io_cqring_offsets cq_off;
245 * io_uring_params->features flags
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)
256 * io_uring_register(2) opcodes and arguments
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
270 struct io_uring_files_update {
273 __aligned_u64 /* __s32 * */ fds;
276 #define IO_URING_OP_SUPPORTED (1U << 0)
278 struct io_uring_probe_op {
281 __u16 flags; /* IO_URING_OP_* flags */
285 struct io_uring_probe {
286 __u8 last_op; /* last opcode supported */
287 __u8 ops_len; /* length of ops[] array below */
290 struct io_uring_probe_op ops[0];