tools/io_uring/liburing.h

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