t/io_uring: add IORING_OP_NOP support
[fio.git] / os / io_uring.h
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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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 __u64 off; /* offset into file */
23 union {
24 void *addr; /* buffer or iovecs */
25 __u64 __pad;
26 };
27 __u32 len; /* buffer size or number of iovecs */
28 union {
29 __kernel_rwf_t rw_flags;
30 __u32 fsync_flags;
31 };
32 __u16 buf_index; /* index into fixed buffers, if used */
33 __u16 __pad2;
34 __u32 __pad3;
35 __u64 user_data; /* data to be passed back at completion time */
36};
37
38/*
39 * sqe->flags
40 */
41#define IOSQE_FIXED_FILE (1 << 0) /* use fixed fileset */
42
43/*
44 * io_uring_setup() flags
45 */
46#define IORING_SETUP_IOPOLL (1 << 0) /* io_context is polled */
47#define IORING_SETUP_SQPOLL (1 << 1) /* SQ poll thread */
48#define IORING_SETUP_SQ_AFF (1 << 2) /* sq_thread_cpu is valid */
49
50#define IORING_OP_NOP 0
51#define IORING_OP_READV 1
52#define IORING_OP_WRITEV 2
53#define IORING_OP_FSYNC 3
54#define IORING_OP_READ_FIXED 4
55#define IORING_OP_WRITE_FIXED 5
56
57/*
58 * sqe->fsync_flags
59 */
60#define IORING_FSYNC_DATASYNC (1 << 0)
61
62/*
63 * IO completion data structure (Completion Queue Entry)
64 */
65struct io_uring_cqe {
66 __u64 user_data; /* sqe->data submission passed back */
67 __s32 res; /* result code for this event */
68 __u32 flags;
69};
70
71/*
72 * io_uring_event->flags
73 */
74#define IOCQE_FLAG_CACHEHIT (1 << 0) /* IO did not hit media */
75
76/*
77 * Magic offsets for the application to mmap the data it needs
78 */
79#define IORING_OFF_SQ_RING 0ULL
80#define IORING_OFF_CQ_RING 0x8000000ULL
81#define IORING_OFF_SQES 0x10000000ULL
82
83/*
84 * Filled with the offset for mmap(2)
85 */
86struct io_sqring_offsets {
87 __u32 head;
88 __u32 tail;
89 __u32 ring_mask;
90 __u32 ring_entries;
91 __u32 flags;
92 __u32 dropped;
93 __u32 array;
94 __u32 resv[3];
95};
96
97/*
98 * sq_ring->flags
99 */
100#define IORING_SQ_NEED_WAKEUP (1 << 0) /* needs io_uring_enter wakeup */
101
102struct io_cqring_offsets {
103 __u32 head;
104 __u32 tail;
105 __u32 ring_mask;
106 __u32 ring_entries;
107 __u32 overflow;
108 __u32 cqes;
109 __u32 resv[4];
110};
111
112/*
113 * io_uring_enter(2) flags
114 */
115#define IORING_ENTER_GETEVENTS (1 << 0)
116
117/*
118 * Passed in for io_uring_setup(2). Copied back with updated info on success
119 */
120struct io_uring_params {
121 __u32 sq_entries;
122 __u32 cq_entries;
123 __u32 flags;
124 __u16 sq_thread_cpu;
125 __u16 resv[9];
126 struct io_sqring_offsets sq_off;
127 struct io_cqring_offsets cq_off;
128};
129
130/*
131 * io_uring_register(2) opcodes and arguments
132 */
133#define IORING_REGISTER_BUFFERS 0
134#define IORING_UNREGISTER_BUFFERS 1
135#define IORING_REGISTER_FILES 2
136#define IORING_UNREGISTER_FILES 3
137
138struct io_uring_register_buffers {
139 struct iovec *iovecs;
140 __u32 nr_iovecs;
141};
142
143struct io_uring_register_files {
144 __s32 *fds;
145 __u32 nr_fds;
146};
147
148#endif