include/uapi/linux/io_uring.h

   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