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 */ 17 struct 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 union { 23 __u64 off; /* offset into file */ 24 __u64 addr2; 25 }; 26 __u64 addr; /* pointer to buffer or iovecs */ 27 __u32 len; /* buffer size or number of iovecs */ 28 union { 29 __kernel_rwf_t rw_flags; 30 __u32 fsync_flags; 31 __u16 poll_events; 32 __u32 sync_range_flags; 33 __u32 msg_flags; 34 __u32 timeout_flags; 35 __u32 accept_flags; 36 __u32 cancel_flags; 37 }; 38 __u64 user_data; /* data to be passed back at completion time */ 39 union { 40 __u16 buf_index; /* index into fixed buffers, if used */ 41 __u64 __pad2[3]; 42 }; 43 }; 44 45 /* 46 * sqe->flags 47 */ 48 #define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */ 49 #define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */ 50 #define IOSQE_IO_LINK (1U << 2) /* links next sqe */ 51 #define IOSQE_IO_HARDLINK (1U << 3) /* like LINK, but stronger */ 52 53 /* 54 * io_uring_setup() flags 55 */ 56 #define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */ 57 #define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */ 58 #define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */ 59 #define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */ 60 61 enum { 62 IORING_OP_NOP, 63 IORING_OP_READV, 64 IORING_OP_WRITEV, 65 IORING_OP_FSYNC, 66 IORING_OP_READ_FIXED, 67 IORING_OP_WRITE_FIXED, 68 IORING_OP_POLL_ADD, 69 IORING_OP_POLL_REMOVE, 70 IORING_OP_SYNC_FILE_RANGE, 71 IORING_OP_SENDMSG, 72 IORING_OP_RECVMSG, 73 IORING_OP_TIMEOUT, 74 IORING_OP_TIMEOUT_REMOVE, 75 IORING_OP_ACCEPT, 76 IORING_OP_ASYNC_CANCEL, 77 IORING_OP_LINK_TIMEOUT, 78 IORING_OP_CONNECT, 79 80 /* this goes last, obviously */ 81 IORING_OP_LAST, 82 }; 83 84 /* 85 * sqe->fsync_flags 86 */ 87 #define IORING_FSYNC_DATASYNC (1U << 0) 88 89 /* 90 * sqe->timeout_flags 91 */ 92 #define IORING_TIMEOUT_ABS (1U << 0) 93 94 /* 95 * IO completion data structure (Completion Queue Entry) 96 */ 97 struct io_uring_cqe { 98 __u64 user_data; /* sqe->data submission passed back */ 99 __s32 res; /* result code for this event */ 100 __u32 flags; 101 }; 102 103 /* 104 * Magic offsets for the application to mmap the data it needs 105 */ 106 #define IORING_OFF_SQ_RING 0ULL 107 #define IORING_OFF_CQ_RING 0x8000000ULL 108 #define IORING_OFF_SQES 0x10000000ULL 109 110 /* 111 * Filled with the offset for mmap(2) 112 */ 113 struct io_sqring_offsets { 114 __u32 head; 115 __u32 tail; 116 __u32 ring_mask; 117 __u32 ring_entries; 118 __u32 flags; 119 __u32 dropped; 120 __u32 array; 121 __u32 resv1; 122 __u64 resv2; 123 }; 124 125 /* 126 * sq_ring->flags 127 */ 128 #define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */ 129 130 struct io_cqring_offsets { 131 __u32 head; 132 __u32 tail; 133 __u32 ring_mask; 134 __u32 ring_entries; 135 __u32 overflow; 136 __u32 cqes; 137 __u64 resv[2]; 138 }; 139 140 /* 141 * io_uring_enter(2) flags 142 */ 143 #define IORING_ENTER_GETEVENTS (1U << 0) 144 #define IORING_ENTER_SQ_WAKEUP (1U << 1) 145 146 /* 147 * Passed in for io_uring_setup(2). Copied back with updated info on success 148 */ 149 struct io_uring_params { 150 __u32 sq_entries; 151 __u32 cq_entries; 152 __u32 flags; 153 __u32 sq_thread_cpu; 154 __u32 sq_thread_idle; 155 __u32 features; 156 __u32 resv[4]; 157 struct io_sqring_offsets sq_off; 158 struct io_cqring_offsets cq_off; 159 }; 160 161 /* 162 * io_uring_params->features flags 163 */ 164 #define IORING_FEAT_SINGLE_MMAP (1U << 0) 165 #define IORING_FEAT_NODROP (1U << 1) 166 #define IORING_FEAT_SUBMIT_STABLE (1U << 2) 167 168 /* 169 * io_uring_register(2) opcodes and arguments 170 */ 171 #define IORING_REGISTER_BUFFERS 0 172 #define IORING_UNREGISTER_BUFFERS 1 173 #define IORING_REGISTER_FILES 2 174 #define IORING_UNREGISTER_FILES 3 175 #define IORING_REGISTER_EVENTFD 4 176 #define IORING_UNREGISTER_EVENTFD 5 177 #define IORING_REGISTER_FILES_UPDATE 6 178 179 struct io_uring_files_update { 180 __u32 offset; 181 __s32 *fds; 182 }; 183 184 #endif 185