io_uring: ensure that the io_uring_register() structs are 32-bit safe
[fio.git] / os / linux / 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 __u64 user_data; /* data to be passed back at completion time */
33 union {
34 __u16 buf_index; /* index into fixed buffers, if used */
35 __u64 __pad2[3];
36 };
37};
38
39/*
40 * sqe->flags
41 */
42#define IOSQE_FIXED_FILE (1 << 0) /* use fixed fileset */
43
44/*
45 * io_uring_setup() flags
46 */
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 */
50
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
58/*
59 * sqe->fsync_flags
60 */
61#define IORING_FSYNC_DATASYNC (1 << 0)
62
63/*
64 * IO completion data structure (Completion Queue Entry)
65 */
66struct io_uring_cqe {
67 __u64 user_data; /* sqe->data submission passed back */
68 __s32 res; /* result code for this event */
69 __u32 flags;
70};
71
72/*
73 * io_uring_event->flags
74 */
75#define IOCQE_FLAG_CACHEHIT (1 << 0) /* IO did not hit media */
76
77/*
78 * Magic offsets for the application to mmap the data it needs
79 */
80#define IORING_OFF_SQ_RING 0ULL
81#define IORING_OFF_CQ_RING 0x8000000ULL
82#define IORING_OFF_SQES 0x10000000ULL
83
84/*
85 * Filled with the offset for mmap(2)
86 */
87struct io_sqring_offsets {
88 __u32 head;
89 __u32 tail;
90 __u32 ring_mask;
91 __u32 ring_entries;
92 __u32 flags;
93 __u32 dropped;
94 __u32 array;
95 __u32 resv[3];
96};
97
98/*
99 * sq_ring->flags
100 */
101#define IORING_SQ_NEED_WAKEUP (1 << 0) /* needs io_uring_enter wakeup */
102
103struct io_cqring_offsets {
104 __u32 head;
105 __u32 tail;
106 __u32 ring_mask;
107 __u32 ring_entries;
108 __u32 overflow;
109 __u32 cqes;
110 __u32 resv[4];
111};
112
113/*
114 * io_uring_enter(2) flags
115 */
116#define IORING_ENTER_GETEVENTS (1 << 0)
117
118/*
119 * Passed in for io_uring_setup(2). Copied back with updated info on success
120 */
121struct io_uring_params {
122 __u32 sq_entries;
123 __u32 cq_entries;
124 __u32 flags;
125 __u16 sq_thread_cpu;
126 __u16 resv[9];
127 struct io_sqring_offsets sq_off;
128 struct io_cqring_offsets cq_off;
129};
130
131/*
132 * io_uring_register(2) opcodes and arguments
133 */
134#define IORING_REGISTER_BUFFERS 0
135#define IORING_UNREGISTER_BUFFERS 1
136#define IORING_REGISTER_FILES 2
137#define IORING_UNREGISTER_FILES 3
138
139struct io_uring_register_buffers {
140 union {
141 struct iovec *iovecs;
142 __u64 pad;
143 };
144 __u32 nr_iovecs;
145};
146
147struct io_uring_register_files {
148 union {
149 __s32 *fds;
150 __u64 pad;
151 };
152 __u32 nr_fds;
153};
154
155#endif