1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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>
14 #define IORING_MAX_ENTRIES 4096
17 * IO submission data structure (Submission Queue Entry)
20 __u8 opcode; /* type of operation for this sqe */
21 __u8 flags; /* IOSQE_ flags */
22 __u16 ioprio; /* ioprio for the request */
23 __s32 fd; /* file descriptor to do IO on */
24 __u64 off; /* offset into file */
25 __u64 addr; /* pointer to buffer or iovecs */
26 __u32 len; /* buffer size or number of iovecs */
28 __kernel_rwf_t rw_flags;
32 __u64 user_data; /* data to be passed back at completion time */
34 __u16 buf_index; /* index into fixed buffers, if used */
42 #define IOSQE_FIXED_FILE (1 << 0) /* use fixed fileset */
45 * io_uring_setup() flags
47 #define IORING_SETUP_IOPOLL (1 << 0) /* io_context is polled */
48 #define IORING_SETUP_SQPOLL (1 << 1) /* SQ poll thread */
49 #define IORING_SETUP_SQ_AFF (1 << 2) /* sq_thread_cpu is valid */
51 #define IORING_OP_NOP 0
52 #define IORING_OP_READV 1
53 #define IORING_OP_WRITEV 2
54 #define IORING_OP_FSYNC 3
55 #define IORING_OP_READ_FIXED 4
56 #define IORING_OP_WRITE_FIXED 5
57 #define IORING_OP_POLL_ADD 6
58 #define IORING_OP_POLL_REMOVE 7
63 #define IORING_FSYNC_DATASYNC (1 << 0)
66 * IO completion data structure (Completion Queue Entry)
69 __u64 user_data; /* sqe->data submission passed back */
70 __s32 res; /* result code for this event */
75 * io_uring_event->flags
77 #define IOCQE_FLAG_CACHEHIT (1 << 0) /* IO did not hit media */
80 * Magic offsets for the application to mmap the data it needs
82 #define IORING_OFF_SQ_RING 0ULL
83 #define IORING_OFF_CQ_RING 0x8000000ULL
84 #define IORING_OFF_SQES 0x10000000ULL
87 * Filled with the offset for mmap(2)
89 struct io_sqring_offsets {
103 #define IORING_SQ_NEED_WAKEUP (1 << 0) /* needs io_uring_enter wakeup */
105 struct io_cqring_offsets {
116 * io_uring_enter(2) flags
118 #define IORING_ENTER_GETEVENTS (1 << 0)
119 #define IORING_ENTER_SQ_WAKEUP (1 << 1)
122 * Passed in for io_uring_setup(2). Copied back with updated info on success
124 struct io_uring_params {
129 __u16 sq_thread_idle;
131 struct io_sqring_offsets sq_off;
132 struct io_cqring_offsets cq_off;
136 * io_uring_register(2) opcodes and arguments
138 #define IORING_REGISTER_BUFFERS 0
139 #define IORING_UNREGISTER_BUFFERS 1
140 #define IORING_REGISTER_FILES 2
141 #define IORING_UNREGISTER_FILES 3