/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
/*
 * Header file for the io_uring interface.
 *
 * Copyright (C) 2019 Jens Axboe
 * Copyright (C) 2019 Christoph Hellwig
 */
#ifndef LINUX_IO_URING_H
#define LINUX_IO_URING_H

#include <linux/fs.h>
#include <linux/types.h>
/*
 * this file is shared with liburing and that has to autodetect
 * if linux/time_types.h is available or not, it can
 * define UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
 * if linux/time_types.h is not available
 */
#ifndef UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
#include <linux/time_types.h>
#endif

#ifdef __cplusplus
extern "C" {
#endif

/*
 * IO submission data structure (Submission Queue Entry)
 */
struct io_uring_sqe {
        __u8    opcode;         /* type of operation for this sqe */
        __u8    flags;          /* IOSQE_ flags */
        __u16   ioprio;         /* ioprio for the request */
        __s32   fd;             /* file descriptor to do IO on */
        union {
                __u64   off;    /* offset into file */
                __u64   addr2;
                struct {
                        __u32   cmd_op;
                        __u32   __pad1;
                };
        };
        union {
                __u64   addr;   /* pointer to buffer or iovecs */
                __u64   splice_off_in;
                struct {
                        __u32   level;
                        __u32   optname;
                };
        };
        __u32   len;            /* buffer size or number of iovecs */
        union {
                __kernel_rwf_t  rw_flags;
                __u32           fsync_flags;
                __u16           poll_events;    /* compatibility */
                __u32           poll32_events;  /* word-reversed for BE */
                __u32           sync_range_flags;
                __u32           msg_flags;
                __u32           timeout_flags;
                __u32           accept_flags;
                __u32           cancel_flags;
                __u32           open_flags;
                __u32           statx_flags;
                __u32           fadvise_advice;
                __u32           splice_flags;
                __u32           rename_flags;
                __u32           unlink_flags;
                __u32           hardlink_flags;
                __u32           xattr_flags;
                __u32           msg_ring_flags;
                __u32           uring_cmd_flags;
                __u32           waitid_flags;
                __u32           futex_flags;
        };
        __u64   user_data;      /* data to be passed back at completion time */
        /* pack this to avoid bogus arm OABI complaints */
        union {
                /* index into fixed buffers, if used */
                __u16   buf_index;
                /* for grouped buffer selection */
                __u16   buf_group;
        } __attribute__((packed));
        /* personality to use, if used */
        __u16   personality;
        union {
                __s32   splice_fd_in;
                __u32   file_index;
                __u32   optlen;
                struct {
                        __u16   addr_len;
                        __u16   __pad3[1];
                };
        };
        union {
                struct {
                        __u64   addr3;
                        __u64   __pad2[1];
                };
                __u64   optval;
                /*
                 * If the ring is initialized with IORING_SETUP_SQE128, then
                 * this field is used for 80 bytes of arbitrary command data
                 */
                __u8    cmd[0];
        };
};

/*
 * If sqe->file_index is set to this for opcodes that instantiate a new
 * direct descriptor (like openat/openat2/accept), then io_uring will allocate
 * an available direct descriptor instead of having the application pass one
 * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE
 * if the space is full.
 */
#define IORING_FILE_INDEX_ALLOC         (~0U)

enum {
        IOSQE_FIXED_FILE_BIT,
        IOSQE_IO_DRAIN_BIT,
        IOSQE_IO_LINK_BIT,
        IOSQE_IO_HARDLINK_BIT,
        IOSQE_ASYNC_BIT,
        IOSQE_BUFFER_SELECT_BIT,
        IOSQE_CQE_SKIP_SUCCESS_BIT,
};

/*
 * sqe->flags
 */
/* use fixed fileset */
#define IOSQE_FIXED_FILE        (1U << IOSQE_FIXED_FILE_BIT)
/* issue after inflight IO */
#define IOSQE_IO_DRAIN          (1U << IOSQE_IO_DRAIN_BIT)
/* links next sqe */
#define IOSQE_IO_LINK           (1U << IOSQE_IO_LINK_BIT)
/* like LINK, but stronger */
#define IOSQE_IO_HARDLINK       (1U << IOSQE_IO_HARDLINK_BIT)
/* always go async */
#define IOSQE_ASYNC             (1U << IOSQE_ASYNC_BIT)
/* select buffer from sqe->buf_group */
#define IOSQE_BUFFER_SELECT     (1U << IOSQE_BUFFER_SELECT_BIT)
/* don't post CQE if request succeeded */
#define IOSQE_CQE_SKIP_SUCCESS  (1U << IOSQE_CQE_SKIP_SUCCESS_BIT)

/*
 * io_uring_setup() flags
 */
#define IORING_SETUP_IOPOLL     (1U << 0)       /* io_context is polled */
#define IORING_SETUP_SQPOLL     (1U << 1)       /* SQ poll thread */
#define IORING_SETUP_SQ_AFF     (1U << 2)       /* sq_thread_cpu is valid */
#define IORING_SETUP_CQSIZE     (1U << 3)       /* app defines CQ size */
#define IORING_SETUP_CLAMP      (1U << 4)       /* clamp SQ/CQ ring sizes */
#define IORING_SETUP_ATTACH_WQ  (1U << 5)       /* attach to existing wq */
#define IORING_SETUP_R_DISABLED (1U << 6)       /* start with ring disabled */
#define IORING_SETUP_SUBMIT_ALL (1U << 7)       /* continue submit on error */
/*
 * Cooperative task running. When requests complete, they often require
 * forcing the submitter to transition to the kernel to complete. If this
 * flag is set, work will be done when the task transitions anyway, rather
 * than force an inter-processor interrupt reschedule. This avoids interrupting
 * a task running in userspace, and saves an IPI.
 */
#define IORING_SETUP_COOP_TASKRUN       (1U << 8)
/*
 * If COOP_TASKRUN is set, get notified if task work is available for
 * running and a kernel transition would be needed to run it. This sets
 * IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN.
 */
#define IORING_SETUP_TASKRUN_FLAG       (1U << 9)
#define IORING_SETUP_SQE128             (1U << 10) /* SQEs are 128 byte */
#define IORING_SETUP_CQE32              (1U << 11) /* CQEs are 32 byte */
/*
 * Only one task is allowed to submit requests
 */
#define IORING_SETUP_SINGLE_ISSUER      (1U << 12)

/*
 * Defer running task work to get events.
 * Rather than running bits of task work whenever the task transitions
 * try to do it just before it is needed.
 */
#define IORING_SETUP_DEFER_TASKRUN      (1U << 13)

/*
 * Application provides the memory for the rings
 */
#define IORING_SETUP_NO_MMAP            (1U << 14)

/*
 * Register the ring fd in itself for use with
 * IORING_REGISTER_USE_REGISTERED_RING; return a registered fd index rather
 * than an fd.
 */
#define IORING_SETUP_REGISTERED_FD_ONLY (1U << 15)

/*
 * Removes indirection through the SQ index array.
 */
#define IORING_SETUP_NO_SQARRAY         (1U << 16)

enum io_uring_op {
        IORING_OP_NOP,
        IORING_OP_READV,
        IORING_OP_WRITEV,
        IORING_OP_FSYNC,
        IORING_OP_READ_FIXED,
        IORING_OP_WRITE_FIXED,
        IORING_OP_POLL_ADD,
        IORING_OP_POLL_REMOVE,
        IORING_OP_SYNC_FILE_RANGE,
        IORING_OP_SENDMSG,
        IORING_OP_RECVMSG,
        IORING_OP_TIMEOUT,
        IORING_OP_TIMEOUT_REMOVE,
        IORING_OP_ACCEPT,
        IORING_OP_ASYNC_CANCEL,
        IORING_OP_LINK_TIMEOUT,
        IORING_OP_CONNECT,
        IORING_OP_FALLOCATE,
        IORING_OP_OPENAT,
        IORING_OP_CLOSE,
        IORING_OP_FILES_UPDATE,
        IORING_OP_STATX,
        IORING_OP_READ,
        IORING_OP_WRITE,
        IORING_OP_FADVISE,
        IORING_OP_MADVISE,
        IORING_OP_SEND,
        IORING_OP_RECV,
        IORING_OP_OPENAT2,
        IORING_OP_EPOLL_CTL,
        IORING_OP_SPLICE,
        IORING_OP_PROVIDE_BUFFERS,
        IORING_OP_REMOVE_BUFFERS,
        IORING_OP_TEE,
        IORING_OP_SHUTDOWN,
        IORING_OP_RENAMEAT,
        IORING_OP_UNLINKAT,
        IORING_OP_MKDIRAT,
        IORING_OP_SYMLINKAT,
        IORING_OP_LINKAT,
        IORING_OP_MSG_RING,
        IORING_OP_FSETXATTR,
        IORING_OP_SETXATTR,
        IORING_OP_FGETXATTR,
        IORING_OP_GETXATTR,
        IORING_OP_SOCKET,
        IORING_OP_URING_CMD,
        IORING_OP_SEND_ZC,
        IORING_OP_SENDMSG_ZC,
        IORING_OP_READ_MULTISHOT,
        IORING_OP_WAITID,
        IORING_OP_FUTEX_WAIT,
        IORING_OP_FUTEX_WAKE,
        IORING_OP_FUTEX_WAITV,

        /* this goes last, obviously */
        IORING_OP_LAST,
};

/*
 * sqe->uring_cmd_flags         top 8bits aren't available for userspace
 * IORING_URING_CMD_FIXED       use registered buffer; pass this flag
 *                              along with setting sqe->buf_index.
 */
#define IORING_URING_CMD_FIXED  (1U << 0)
#define IORING_URING_CMD_MASK   IORING_URING_CMD_FIXED


/*
 * sqe->fsync_flags
 */
#define IORING_FSYNC_DATASYNC   (1U << 0)

/*
 * sqe->timeout_flags
 */
#define IORING_TIMEOUT_ABS              (1U << 0)
#define IORING_TIMEOUT_UPDATE           (1U << 1)
#define IORING_TIMEOUT_BOOTTIME         (1U << 2)
#define IORING_TIMEOUT_REALTIME         (1U << 3)
#define IORING_LINK_TIMEOUT_UPDATE      (1U << 4)
#define IORING_TIMEOUT_ETIME_SUCCESS    (1U << 5)
#define IORING_TIMEOUT_MULTISHOT        (1U << 6)
#define IORING_TIMEOUT_CLOCK_MASK       (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
#define IORING_TIMEOUT_UPDATE_MASK      (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
/*
 * sqe->splice_flags
 * extends splice(2) flags
 */
#define SPLICE_F_FD_IN_FIXED    (1U << 31) /* the last bit of __u32 */

/*
 * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
 * command flags for POLL_ADD are stored in sqe->len.
 *
 * IORING_POLL_ADD_MULTI        Multishot poll. Sets IORING_CQE_F_MORE if
 *                              the poll handler will continue to report
 *                              CQEs on behalf of the same SQE.
 *
 * IORING_POLL_UPDATE           Update existing poll request, matching
 *                              sqe->addr as the old user_data field.
 *
 * IORING_POLL_LEVEL            Level triggered poll.
 */
#define IORING_POLL_ADD_MULTI   (1U << 0)
#define IORING_POLL_UPDATE_EVENTS       (1U << 1)
#define IORING_POLL_UPDATE_USER_DATA    (1U << 2)
#define IORING_POLL_ADD_LEVEL           (1U << 3)

/*
 * ASYNC_CANCEL flags.
 *
 * IORING_ASYNC_CANCEL_ALL      Cancel all requests that match the given key
 * IORING_ASYNC_CANCEL_FD       Key off 'fd' for cancelation rather than the
 *                              request 'user_data'
 * IORING_ASYNC_CANCEL_ANY      Match any request
 * IORING_ASYNC_CANCEL_FD_FIXED 'fd' passed in is a fixed descriptor
 * IORING_ASYNC_CANCEL_USERDATA Match on user_data, default for no other key
 * IORING_ASYNC_CANCEL_OP       Match request based on opcode
 */
#define IORING_ASYNC_CANCEL_ALL (1U << 0)
#define IORING_ASYNC_CANCEL_FD  (1U << 1)
#define IORING_ASYNC_CANCEL_ANY (1U << 2)
#define IORING_ASYNC_CANCEL_FD_FIXED    (1U << 3)
#define IORING_ASYNC_CANCEL_USERDATA    (1U << 4)
#define IORING_ASYNC_CANCEL_OP  (1U << 5)

/*
 * send/sendmsg and recv/recvmsg flags (sqe->ioprio)
 *
 * IORING_RECVSEND_POLL_FIRST   If set, instead of first attempting to send
 *                              or receive and arm poll if that yields an
 *                              -EAGAIN result, arm poll upfront and skip
 *                              the initial transfer attempt.
 *
 * IORING_RECV_MULTISHOT        Multishot recv. Sets IORING_CQE_F_MORE if
 *                              the handler will continue to report
 *                              CQEs on behalf of the same SQE.
 *
 * IORING_RECVSEND_FIXED_BUF    Use registered buffers, the index is stored in
 *                              the buf_index field.
 *
 * IORING_SEND_ZC_REPORT_USAGE
 *                              If set, SEND[MSG]_ZC should report
 *                              the zerocopy usage in cqe.res
 *                              for the IORING_CQE_F_NOTIF cqe.
 *                              0 is reported if zerocopy was actually possible.
 *                              IORING_NOTIF_USAGE_ZC_COPIED if data was copied
 *                              (at least partially).
 */
#define IORING_RECVSEND_POLL_FIRST      (1U << 0)
#define IORING_RECV_MULTISHOT           (1U << 1)
#define IORING_RECVSEND_FIXED_BUF       (1U << 2)
#define IORING_SEND_ZC_REPORT_USAGE     (1U << 3)

/*
 * cqe.res for IORING_CQE_F_NOTIF if
 * IORING_SEND_ZC_REPORT_USAGE was requested
 *
 * It should be treated as a flag, all other
 * bits of cqe.res should be treated as reserved!
 */
#define IORING_NOTIF_USAGE_ZC_COPIED    (1U << 31)

/*
 * accept flags stored in sqe->ioprio
 */
#define IORING_ACCEPT_MULTISHOT (1U << 0)

/*
 * IORING_OP_MSG_RING command types, stored in sqe->addr
 */
enum {
        IORING_MSG_DATA,        /* pass sqe->len as 'res' and off as user_data */
        IORING_MSG_SEND_FD,     /* send a registered fd to another ring */
};

/*
 * IORING_OP_MSG_RING flags (sqe->msg_ring_flags)
 *
 * IORING_MSG_RING_CQE_SKIP     Don't post a CQE to the target ring. Not
 *                              applicable for IORING_MSG_DATA, obviously.
 */
#define IORING_MSG_RING_CQE_SKIP        (1U << 0)
/* Pass through the flags from sqe->file_index to cqe->flags */
#define IORING_MSG_RING_FLAGS_PASS      (1U << 1)

/*
 * IO completion data structure (Completion Queue Entry)
 */
struct io_uring_cqe {
        __u64   user_data;      /* sqe->data submission passed back */
        __s32   res;            /* result code for this event */
        __u32   flags;

        /*
         * If the ring is initialized with IORING_SETUP_CQE32, then this field
         * contains 16-bytes of padding, doubling the size of the CQE.
         */
        __u64 big_cqe[];
};

/*
 * cqe->flags
 *
 * IORING_CQE_F_BUFFER  If set, the upper 16 bits are the buffer ID
 * IORING_CQE_F_MORE    If set, parent SQE will generate more CQE entries
 * IORING_CQE_F_SOCK_NONEMPTY   If set, more data to read after socket recv
 * IORING_CQE_F_NOTIF   Set for notification CQEs. Can be used to distinct
 *                      them from sends.
 */
#define IORING_CQE_F_BUFFER             (1U << 0)
#define IORING_CQE_F_MORE               (1U << 1)
#define IORING_CQE_F_SOCK_NONEMPTY      (1U << 2)
#define IORING_CQE_F_NOTIF              (1U << 3)

enum {
        IORING_CQE_BUFFER_SHIFT         = 16,
};

/*
 * Magic offsets for the application to mmap the data it needs
 */
#define IORING_OFF_SQ_RING              0ULL
#define IORING_OFF_CQ_RING              0x8000000ULL
#define IORING_OFF_SQES                 0x10000000ULL
#define IORING_OFF_PBUF_RING            0x80000000ULL
#define IORING_OFF_PBUF_SHIFT           16
#define IORING_OFF_MMAP_MASK            0xf8000000ULL

/*
 * Filled with the offset for mmap(2)
 */
struct io_sqring_offsets {
        __u32 head;
        __u32 tail;
        __u32 ring_mask;
        __u32 ring_entries;
        __u32 flags;
        __u32 dropped;
        __u32 array;
        __u32 resv1;
        __u64 user_addr;
};

/*
 * sq_ring->flags
 */
#define IORING_SQ_NEED_WAKEUP   (1U << 0) /* needs io_uring_enter wakeup */
#define IORING_SQ_CQ_OVERFLOW   (1U << 1) /* CQ ring is overflown */
#define IORING_SQ_TASKRUN       (1U << 2) /* task should enter the kernel */

struct io_cqring_offsets {
        __u32 head;
        __u32 tail;
        __u32 ring_mask;
        __u32 ring_entries;
        __u32 overflow;
        __u32 cqes;
        __u32 flags;
        __u32 resv1;
        __u64 user_addr;
};

/*
 * cq_ring->flags
 */

/* disable eventfd notifications */
#define IORING_CQ_EVENTFD_DISABLED      (1U << 0)

/*
 * io_uring_enter(2) flags
 */
#define IORING_ENTER_GETEVENTS          (1U << 0)
#define IORING_ENTER_SQ_WAKEUP          (1U << 1)
#define IORING_ENTER_SQ_WAIT            (1U << 2)
#define IORING_ENTER_EXT_ARG            (1U << 3)
#define IORING_ENTER_REGISTERED_RING    (1U << 4)

/*
 * Passed in for io_uring_setup(2). Copied back with updated info on success
 */
struct io_uring_params {
        __u32 sq_entries;
        __u32 cq_entries;
        __u32 flags;
        __u32 sq_thread_cpu;
        __u32 sq_thread_idle;
        __u32 features;
        __u32 wq_fd;
        __u32 resv[3];
        struct io_sqring_offsets sq_off;
        struct io_cqring_offsets cq_off;
};

/*
 * io_uring_params->features flags
 */
#define IORING_FEAT_SINGLE_MMAP         (1U << 0)
#define IORING_FEAT_NODROP              (1U << 1)
#define IORING_FEAT_SUBMIT_STABLE       (1U << 2)
#define IORING_FEAT_RW_CUR_POS          (1U << 3)
#define IORING_FEAT_CUR_PERSONALITY     (1U << 4)
#define IORING_FEAT_FAST_POLL           (1U << 5)
#define IORING_FEAT_POLL_32BITS         (1U << 6)
#define IORING_FEAT_SQPOLL_NONFIXED     (1U << 7)
#define IORING_FEAT_EXT_ARG             (1U << 8)
#define IORING_FEAT_NATIVE_WORKERS      (1U << 9)
#define IORING_FEAT_RSRC_TAGS           (1U << 10)
#define IORING_FEAT_CQE_SKIP            (1U << 11)
#define IORING_FEAT_LINKED_FILE         (1U << 12)
#define IORING_FEAT_REG_REG_RING        (1U << 13)

/*
 * io_uring_register(2) opcodes and arguments
 */
enum {
        IORING_REGISTER_BUFFERS                 = 0,
        IORING_UNREGISTER_BUFFERS               = 1,
        IORING_REGISTER_FILES                   = 2,
        IORING_UNREGISTER_FILES                 = 3,
        IORING_REGISTER_EVENTFD                 = 4,
        IORING_UNREGISTER_EVENTFD               = 5,
        IORING_REGISTER_FILES_UPDATE            = 6,
        IORING_REGISTER_EVENTFD_ASYNC           = 7,
        IORING_REGISTER_PROBE                   = 8,
        IORING_REGISTER_PERSONALITY             = 9,
        IORING_UNREGISTER_PERSONALITY           = 10,
        IORING_REGISTER_RESTRICTIONS            = 11,
        IORING_REGISTER_ENABLE_RINGS            = 12,

        /* extended with tagging */
        IORING_REGISTER_FILES2                  = 13,
        IORING_REGISTER_FILES_UPDATE2           = 14,
        IORING_REGISTER_BUFFERS2                = 15,
        IORING_REGISTER_BUFFERS_UPDATE          = 16,

        /* set/clear io-wq thread affinities */
        IORING_REGISTER_IOWQ_AFF                = 17,
        IORING_UNREGISTER_IOWQ_AFF              = 18,

        /* set/get max number of io-wq workers */
        IORING_REGISTER_IOWQ_MAX_WORKERS        = 19,

        /* register/unregister io_uring fd with the ring */
        IORING_REGISTER_RING_FDS                = 20,
        IORING_UNREGISTER_RING_FDS              = 21,

        /* register ring based provide buffer group */
        IORING_REGISTER_PBUF_RING               = 22,
        IORING_UNREGISTER_PBUF_RING             = 23,

        /* sync cancelation API */
        IORING_REGISTER_SYNC_CANCEL             = 24,

        /* register a range of fixed file slots for automatic slot allocation */
        IORING_REGISTER_FILE_ALLOC_RANGE        = 25,

        /* this goes last */
        IORING_REGISTER_LAST,

        /* flag added to the opcode to use a registered ring fd */
        IORING_REGISTER_USE_REGISTERED_RING     = 1U << 31
};

/* io-wq worker categories */
enum {
        IO_WQ_BOUND,
        IO_WQ_UNBOUND,
};

/* deprecated, see struct io_uring_rsrc_update */
struct io_uring_files_update {
        __u32 offset;
        __u32 resv;
        __aligned_u64 /* __s32 * */ fds;
};

/*
 * Register a fully sparse file space, rather than pass in an array of all
 * -1 file descriptors.
 */
#define IORING_RSRC_REGISTER_SPARSE     (1U << 0)

struct io_uring_rsrc_register {
        __u32 nr;
        __u32 flags;
        __u64 resv2;
        __aligned_u64 data;
        __aligned_u64 tags;
};

struct io_uring_rsrc_update {
        __u32 offset;
        __u32 resv;
        __aligned_u64 data;
};

struct io_uring_rsrc_update2 {
        __u32 offset;
        __u32 resv;
        __aligned_u64 data;
        __aligned_u64 tags;
        __u32 nr;
        __u32 resv2;
};

/* Skip updating fd indexes set to this value in the fd table */
#define IORING_REGISTER_FILES_SKIP      (-2)

#define IO_URING_OP_SUPPORTED   (1U << 0)

struct io_uring_probe_op {
        __u8 op;
        __u8 resv;
        __u16 flags;    /* IO_URING_OP_* flags */
        __u32 resv2;
};

struct io_uring_probe {
        __u8 last_op;   /* last opcode supported */
        __u8 ops_len;   /* length of ops[] array below */
        __u16 resv;
        __u32 resv2[3];
        struct io_uring_probe_op ops[];
};

struct io_uring_restriction {
        __u16 opcode;
        union {
                __u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
                __u8 sqe_op;      /* IORING_RESTRICTION_SQE_OP */
                __u8 sqe_flags;   /* IORING_RESTRICTION_SQE_FLAGS_* */
        };
        __u8 resv;
        __u32 resv2[3];
};

struct io_uring_buf {
        __u64   addr;
        __u32   len;
        __u16   bid;
        __u16   resv;
};

struct io_uring_buf_ring {
        union {
                /*
                 * To avoid spilling into more pages than we need to, the
                 * ring tail is overlaid with the io_uring_buf->resv field.
                 */
                struct {
                        __u64   resv1;
                        __u32   resv2;
                        __u16   resv3;
                        __u16   tail;
                };
                __DECLARE_FLEX_ARRAY(struct io_uring_buf, bufs);
        };
};

/*
 * Flags for IORING_REGISTER_PBUF_RING.
 *
 * IOU_PBUF_RING_MMAP:  If set, kernel will allocate the memory for the ring.
 *                      The application must not set a ring_addr in struct
 *                      io_uring_buf_reg, instead it must subsequently call
 *                      mmap(2) with the offset set as:
 *                      IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)
 *                      to get a virtual mapping for the ring.
 */
enum {
        IOU_PBUF_RING_MMAP      = 1,
};

/* argument for IORING_(UN)REGISTER_PBUF_RING */
struct io_uring_buf_reg {
        __u64   ring_addr;
        __u32   ring_entries;
        __u16   bgid;
        __u16   flags;
        __u64   resv[3];
};

/*
 * io_uring_restriction->opcode values
 */
enum {
        /* Allow an io_uring_register(2) opcode */
        IORING_RESTRICTION_REGISTER_OP          = 0,

        /* Allow an sqe opcode */
        IORING_RESTRICTION_SQE_OP               = 1,

        /* Allow sqe flags */
        IORING_RESTRICTION_SQE_FLAGS_ALLOWED    = 2,

        /* Require sqe flags (these flags must be set on each submission) */
        IORING_RESTRICTION_SQE_FLAGS_REQUIRED   = 3,

        IORING_RESTRICTION_LAST
};

struct io_uring_getevents_arg {
        __u64   sigmask;
        __u32   sigmask_sz;
        __u32   pad;
        __u64   ts;
};

/*
 * Argument for IORING_REGISTER_SYNC_CANCEL
 */
struct io_uring_sync_cancel_reg {
        __u64                           addr;
        __s32                           fd;
        __u32                           flags;
        struct __kernel_timespec        timeout;
        __u8                            opcode;
        __u8                            pad[7];
        __u64                           pad2[3];
};

/*
 * Argument for IORING_REGISTER_FILE_ALLOC_RANGE
 * The range is specified as [off, off + len)
 */
struct io_uring_file_index_range {
        __u32   off;
        __u32   len;
        __u64   resv;
};

struct io_uring_recvmsg_out {
        __u32 namelen;
        __u32 controllen;
        __u32 payloadlen;
        __u32 flags;
};

/*
 * Argument for IORING_OP_URING_CMD when file is a socket
 */
enum {
        SOCKET_URING_OP_SIOCINQ         = 0,
        SOCKET_URING_OP_SIOCOUTQ,
        SOCKET_URING_OP_GETSOCKOPT,
        SOCKET_URING_OP_SETSOCKOPT,
};

#ifdef __cplusplus
}
#endif

#endif