LXR linux/tools/io_uring/liburing.h

   1#ifndef LIB_URING_H
   2#define LIB_URING_H
   3
   4#ifdef __cplusplus
   5extern "C" {
   6#endif
   7
   8#include <sys/uio.h>
   9#include <signal.h>
  10#include <string.h>
  11#include "../../include/uapi/linux/io_uring.h"
  12#include <inttypes.h>
  13#include <linux/swab.h>
  14#include "barrier.h"
  15
  16/*
  17 * Library interface to io_uring
  18 */
  19struct io_uring_sq {
  20        unsigned *khead;
  21        unsigned *ktail;
  22        unsigned *kring_mask;
  23        unsigned *kring_entries;
  24        unsigned *kflags;
  25        unsigned *kdropped;
  26        unsigned *array;
  27        struct io_uring_sqe *sqes;
  28
  29        unsigned sqe_head;
  30        unsigned sqe_tail;
  31
  32        size_t ring_sz;
  33};
  34
  35struct io_uring_cq {
  36        unsigned *khead;
  37        unsigned *ktail;
  38        unsigned *kring_mask;
  39        unsigned *kring_entries;
  40        unsigned *koverflow;
  41        struct io_uring_cqe *cqes;
  42
  43        size_t ring_sz;
  44};
  45
  46struct io_uring {
  47        struct io_uring_sq sq;
  48        struct io_uring_cq cq;
  49        int ring_fd;
  50};
  51
  52/*
  53 * System calls
  54 */
  55extern int io_uring_setup(unsigned entries, struct io_uring_params *p);
  56extern int io_uring_enter(int fd, unsigned to_submit,
  57        unsigned min_complete, unsigned flags, sigset_t *sig);
  58extern int io_uring_register(int fd, unsigned int opcode, void *arg,
  59        unsigned int nr_args);
  60
  61/*
  62 * Library interface
  63 */
  64extern int io_uring_queue_init(unsigned entries, struct io_uring *ring,
  65        unsigned flags);
  66extern int io_uring_queue_mmap(int fd, struct io_uring_params *p,
  67        struct io_uring *ring);
  68extern void io_uring_queue_exit(struct io_uring *ring);
  69extern int io_uring_peek_cqe(struct io_uring *ring,
  70        struct io_uring_cqe **cqe_ptr);
  71extern int io_uring_wait_cqe(struct io_uring *ring,
  72        struct io_uring_cqe **cqe_ptr);
  73extern int io_uring_submit(struct io_uring *ring);
  74extern struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring);
  75
  76/*
  77 * Must be called after io_uring_{peek,wait}_cqe() after the cqe has
  78 * been processed by the application.
  79 */
  80static inline void io_uring_cqe_seen(struct io_uring *ring,
  81                                     struct io_uring_cqe *cqe)
  82{
  83        if (cqe) {
  84                struct io_uring_cq *cq = &ring->cq;
  85
  86                (*cq->khead)++;
  87                /*
  88                 * Ensure that the kernel sees our new head, the kernel has
  89                 * the matching read barrier.
  90                 */
  91                write_barrier();
  92        }
  93}
  94
  95/*
  96 * Command prep helpers
  97 */
  98static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data)
  99{
 100        sqe->user_data = (unsigned long) data;
 101}
 102
 103static inline void *io_uring_cqe_get_data(struct io_uring_cqe *cqe)
 104{
 105        return (void *) (uintptr_t) cqe->user_data;
 106}
 107
 108static inline void io_uring_prep_rw(int op, struct io_uring_sqe *sqe, int fd,
 109                                    const void *addr, unsigned len,
 110                                    off_t offset)
 111{
 112        memset(sqe, 0, sizeof(*sqe));
 113        sqe->opcode = op;
 114        sqe->fd = fd;
 115        sqe->off = offset;
 116        sqe->addr = (unsigned long) addr;
 117        sqe->len = len;
 118}
 119
 120static inline void io_uring_prep_readv(struct io_uring_sqe *sqe, int fd,
 121                                       const struct iovec *iovecs,
 122                                       unsigned nr_vecs, off_t offset)
 123{
 124        io_uring_prep_rw(IORING_OP_READV, sqe, fd, iovecs, nr_vecs, offset);
 125}
 126
 127static inline void io_uring_prep_read_fixed(struct io_uring_sqe *sqe, int fd,
 128                                            void *buf, unsigned nbytes,
 129                                            off_t offset)
 130{
 131        io_uring_prep_rw(IORING_OP_READ_FIXED, sqe, fd, buf, nbytes, offset);
 132}
 133
 134static inline void io_uring_prep_writev(struct io_uring_sqe *sqe, int fd,
 135                                        const struct iovec *iovecs,
 136                                        unsigned nr_vecs, off_t offset)
 137{
 138        io_uring_prep_rw(IORING_OP_WRITEV, sqe, fd, iovecs, nr_vecs, offset);
 139}
 140
 141static inline void io_uring_prep_write_fixed(struct io_uring_sqe *sqe, int fd,
 142                                             const void *buf, unsigned nbytes,
 143                                             off_t offset)
 144{
 145        io_uring_prep_rw(IORING_OP_WRITE_FIXED, sqe, fd, buf, nbytes, offset);
 146}
 147
 148static inline void io_uring_prep_poll_add(struct io_uring_sqe *sqe, int fd,
 149                                          unsigned poll_mask)
 150{
 151        memset(sqe, 0, sizeof(*sqe));
 152        sqe->opcode = IORING_OP_POLL_ADD;
 153        sqe->fd = fd;
 154#if __BYTE_ORDER == __BIG_ENDIAN
 155        poll_mask = __swahw32(poll_mask);
 156#endif
 157        sqe->poll_events = poll_mask;
 158}
 159
 160static inline void io_uring_prep_poll_remove(struct io_uring_sqe *sqe,
 161                                             void *user_data)
 162{
 163        memset(sqe, 0, sizeof(*sqe));
 164        sqe->opcode = IORING_OP_POLL_REMOVE;
 165        sqe->addr = (unsigned long) user_data;
 166}
 167
 168static inline void io_uring_prep_fsync(struct io_uring_sqe *sqe, int fd,
 169                                       unsigned fsync_flags)
 170{
 171        memset(sqe, 0, sizeof(*sqe));
 172        sqe->opcode = IORING_OP_FSYNC;
 173        sqe->fd = fd;
 174        sqe->fsync_flags = fsync_flags;
 175}
 176
 177static inline void io_uring_prep_nop(struct io_uring_sqe *sqe)
 178{
 179        memset(sqe, 0, sizeof(*sqe));
 180        sqe->opcode = IORING_OP_NOP;
 181}
 182
 183#ifdef __cplusplus
 184}
 185#endif
 186
 187#endif
 188