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>
15 * IO submission data structure (Submission Queue Entry)
18 __u8 opcode; /* type of operation for this sqe */
19 __u8 flags; /* as of now unused */
20 __u16 ioprio; /* ioprio for the request */
21 __s32 fd; /* file descriptor to do IO on */
22 __u64 off; /* offset into file */
24 void *addr; /* buffer or iovecs */
27 __u32 len; /* buffer size or number of iovecs */
29 __kernel_rwf_t rw_flags;
32 __u16 index; /* index into fixed buffers, if used */
34 __u64 data; /* data to be passed back at completion time */
38 * io_uring_setup() flags
40 #define IORING_SETUP_IOPOLL (1 << 0) /* io_context is polled */
41 #define IORING_SETUP_SQTHREAD (1 << 1) /* Use SQ thread */
42 #define IORING_SETUP_SQWQ (1 << 2) /* Use SQ workqueue */
43 #define IORING_SETUP_SQPOLL (1 << 3) /* SQ thread polls */
45 #define IORING_OP_READV 1
46 #define IORING_OP_WRITEV 2
47 #define IORING_OP_FSYNC 3
48 #define IORING_OP_FDSYNC 4
49 #define IORING_OP_READ_FIXED 5
50 #define IORING_OP_WRITE_FIXED 6
53 * IO completion data structure (Completion Queue Entry)
56 __u64 data; /* sqe->data submission passed back */
57 __s32 res; /* result code for this event */
62 * io_uring_event->flags
64 #define IOCQE_FLAG_CACHEHIT (1 << 0) /* IO did not hit media */
67 * Magic offsets for the application to mmap the data it needs
69 #define IORING_OFF_SQ_RING 0ULL
70 #define IORING_OFF_CQ_RING 0x8000000ULL
71 #define IORING_OFF_SQES 0x10000000ULL
74 * Filled with the offset for mmap(2)
76 struct io_sqring_offsets {
87 #define IORING_SQ_NEED_WAKEUP (1 << 0) /* needs io_uring_enter wakeup */
89 struct io_cqring_offsets {
100 * io_uring_enter(2) flags
102 #define IORING_ENTER_GETEVENTS (1 << 0)
105 * Passed in for io_uring_setup(2). Copied back with updated info on success
107 struct io_uring_params {
113 struct io_sqring_offsets sq_off;
114 struct io_cqring_offsets cq_off;