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 <linux/swab.h>
  14 #include "barrier.h"
  15
  16 /*
  17  * Library interface to io_uring
  18  */
  19 struct 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
  35 struct 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
  46 struct 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  */
  55 extern int io_uring_setup(unsigned entries, struct io_uring_params *p);
  56 extern int io_uring_enter(int fd, unsigned to_submit,
  57         unsigned min_complete, unsigned flags, sigset_t *sig);
  58 extern int io_uring_register(int fd, unsigned int opcode, void *arg,
  59         unsigned int nr_args);
  60
  61 /*
  62  * Library interface
  63  */
  64 extern int io_uring_queue_init(unsigned entries, struct io_uring *ring,
  65         unsigned flags);
  66 extern int io_uring_queue_mmap(int fd, struct io_uring_params *p,
  67         struct io_uring *ring);
  68 extern void io_uring_queue_exit(struct io_uring *ring);
  69 extern int io_uring_peek_cqe(struct io_uring *ring,
  70         struct io_uring_cqe **cqe_ptr);
  71 extern int io_uring_wait_cqe(struct io_uring *ring,
  72         struct io_uring_cqe **cqe_ptr);
  73 extern int io_uring_submit(struct io_uring *ring);
  74 extern 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  */
  80 static 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  */
  98 static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data)
  99 {
 100         sqe->user_data = (unsigned long) data;
 101 }
 102
 103 static inline void *io_uring_cqe_get_data(struct io_uring_cqe *cqe)
 104 {
 105         return (void *) (uintptr_t) cqe->user_data;
 106 }
 107
 108 static 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
 120 static 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
 127 static 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
 134 static 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
 141 static 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
 148 static 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
 160 static 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
 168 static 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
 177 static 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