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
17 struct io_uring_iocb {
29 __kernel_rwf_t rw_flags;
35 * io_uring_setup() flags
37 #define IORING_SETUP_IOPOLL (1 << 0) /* io_context is polled */
38 #define IORING_SETUP_FIXEDBUFS (1 << 1) /* IO buffers are fixed */
39 #define IORING_SETUP_SQTHREAD (1 << 2) /* Use SQ thread */
40 #define IORING_SETUP_SQWQ (1 << 3) /* Use SQ workqueue */
41 #define IORING_SETUP_SQPOLL (1 << 4) /* SQ thread polls */
43 #define IORING_OP_READ 1
44 #define IORING_OP_WRITE 2
45 #define IORING_OP_FSYNC 3
46 #define IORING_OP_FDSYNC 4
47 #define IORING_OP_READ_FIXED 5
48 #define IORING_OP_WRITE_FIXED 6
51 * IO completion data structure
53 struct io_uring_event {
54 __u64 index; /* what iocb this event came from */
55 __s32 res; /* result code for this event */
60 * io_uring_event->flags
62 #define IOEV_FLAG_CACHEHIT (1 << 0) /* IO did not hit media */
65 * Magic offsets for the application to mmap the data it needs
67 #define IORING_OFF_SQ_RING 0ULL
68 #define IORING_OFF_CQ_RING 0x8000000ULL
69 #define IORING_OFF_IOCB 0x10000000ULL
72 * Filled with the offset for mmap(2)
74 struct io_sqring_offsets {
85 #define IORING_SQ_NEED_WAKEUP (1 << 0) /* needs io_uring_enter wakeup */
87 struct io_cqring_offsets {
98 * io_uring_enter(2) flags
100 #define IORING_ENTER_GETEVENTS (1 << 0)
103 * Passed in for io_uring_setup(2). Copied back with updated info on success
105 struct io_uring_params {
111 struct io_sqring_offsets sq_off;
112 struct io_cqring_offsets cq_off;