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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 __u64 addr; /* pointer to buffer or iovecs */
24 __u32 len; /* buffer size or number of iovecs */
25 union {
26 __kernel_rwf_t rw_flags;
27 __u32 fsync_flags;
28 __u16 poll_events;
29 __u32 sync_range_flags;
30 };
31 __u64 user_data; /* data to be passed back at completion time */
32 union {
33 __u16 buf_index; /* index into fixed buffers, if used */
34 __u64 __pad2[3];
35 };
36};
37
38/*
39 * sqe->flags
40 */
41#define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */
42#define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */
43
44/*
45 * io_uring_setup() flags
46 */
47#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
48#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
49#define IORING_SETUP_SQ_AFF (1U << 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#define IORING_OP_POLL_ADD 6
58#define IORING_OP_POLL_REMOVE 7
59#define IORING_OP_SYNC_FILE_RANGE 8
60
61/*
62 * sqe->fsync_flags
63 */
64#define IORING_FSYNC_DATASYNC (1U << 0)
65
66/*
67 * IO completion data structure (Completion Queue Entry)
68 */
69struct io_uring_cqe {
70 __u64 user_data; /* sqe->data submission passed back */
71 __s32 res; /* result code for this event */
72 __u32 flags;
73};
74
75/*
76 * Magic offsets for the application to mmap the data it needs
77 */
78#define IORING_OFF_SQ_RING 0ULL
79#define IORING_OFF_CQ_RING 0x8000000ULL
80#define IORING_OFF_SQES 0x10000000ULL
81
82/*
83 * Filled with the offset for mmap(2)
84 */
85struct io_sqring_offsets {
86 __u32 head;
87 __u32 tail;
88 __u32 ring_mask;
89 __u32 ring_entries;
90 __u32 flags;
91 __u32 dropped;
92 __u32 array;
93 __u32 resv1;
94 __u64 resv2;
95};
96
97/*
98 * sq_ring->flags
99 */
100#define IORING_SQ_NEED_WAKEUP (1U << 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 __u64 resv[2];
110};
111
112/*
113 * io_uring_enter(2) flags
114 */
115#define IORING_ENTER_GETEVENTS (1U << 0)
116#define IORING_ENTER_SQ_WAKEUP (1U << 1)
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 __u32 sq_thread_cpu;
126 __u32 sq_thread_idle;
127 __u32 resv[5];
128 struct io_sqring_offsets sq_off;
129 struct io_cqring_offsets cq_off;
130};
131
132/*
133 * io_uring_register(2) opcodes and arguments
134 */
135#define IORING_REGISTER_BUFFERS 0
136#define IORING_UNREGISTER_BUFFERS 1
137#define IORING_REGISTER_FILES 2
138#define IORING_UNREGISTER_FILES 3
139#define IORING_REGISTER_EVENTFD 4
140#define IORING_UNREGISTER_EVENTFD 5
141
142#endif