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 __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 }; 30 __u64 user_data; /* data to be passed back at completion time */ 31 union { 32 __u16 buf_index; /* index into fixed buffers, if used */ 33 __u64 __pad2[3]; 34 }; 35 }; 36 37 /* 38 * sqe->flags 39 */ 40 #define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */ 41 42 /* 43 * io_uring_setup() flags 44 */ 45 #define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */ 46 #define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */ 47 #define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */ 48 49 #define IORING_OP_NOP 0 50 #define IORING_OP_READV 1 51 #define IORING_OP_WRITEV 2 52 #define IORING_OP_FSYNC 3 53 #define IORING_OP_READ_FIXED 4 54 #define IORING_OP_WRITE_FIXED 5 55 #define IORING_OP_POLL_ADD 6 56 #define IORING_OP_POLL_REMOVE 7 57 58 /* 59 * sqe->fsync_flags 60 */ 61 #define IORING_FSYNC_DATASYNC (1U << 0) 62 63 /* 64 * IO completion data structure (Completion Queue Entry) 65 */ 66 struct 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 * Magic offsets for the application to mmap the data it needs 74 */ 75 #define IORING_OFF_SQ_RING 0ULL 76 #define IORING_OFF_CQ_RING 0x8000000ULL 77 #define IORING_OFF_SQES 0x10000000ULL 78 79 /* 80 * Filled with the offset for mmap(2) 81 */ 82 struct io_sqring_offsets { 83 __u32 head; 84 __u32 tail; 85 __u32 ring_mask; 86 __u32 ring_entries; 87 __u32 flags; 88 __u32 dropped; 89 __u32 array; 90 __u32 resv1; 91 __u64 resv2; 92 }; 93 94 /* 95 * sq_ring->flags 96 */ 97 #define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */ 98 99 struct io_cqring_offsets { 100 __u32 head; 101 __u32 tail; 102 __u32 ring_mask; 103 __u32 ring_entries; 104 __u32 overflow; 105 __u32 cqes; 106 __u64 resv[2]; 107 }; 108 109 /* 110 * io_uring_enter(2) flags 111 */ 112 #define IORING_ENTER_GETEVENTS (1U << 0) 113 #define IORING_ENTER_SQ_WAKEUP (1U << 1) 114 115 /* 116 * Passed in for io_uring_setup(2). Copied back with updated info on success 117 */ 118 struct io_uring_params { 119 __u32 sq_entries; 120 __u32 cq_entries; 121 __u32 flags; 122 __u32 sq_thread_cpu; 123 __u32 sq_thread_idle; 124 __u32 resv[5]; 125 struct io_sqring_offsets sq_off; 126 struct io_cqring_offsets cq_off; 127 }; 128 129 /* 130 * io_uring_register(2) opcodes and arguments 131 */ 132 #define IORING_REGISTER_BUFFERS 0 133 #define IORING_UNREGISTER_BUFFERS 1 134 #define IORING_REGISTER_FILES 2 135 #define IORING_UNREGISTER_FILES 3 136 137 #endif 138