liburing/src/liburing.h

#ifndef LIB_URING_H
#define LIB_URING_H

#include <sys/uio.h>
#include "compat.h"
#include "io_uring.h"

/*
 * Library interface to io_uring
 */
struct io_uring_sq {
	unsigned *khead;
	unsigned *ktail;
	unsigned *kring_mask;
	unsigned *kring_entries;
	unsigned *kflags;
	unsigned *kdropped;
	unsigned *array;
	struct io_uring_sqe *sqes;

	unsigned sqe_head;
	unsigned sqe_tail;

	size_t ring_sz;
};

struct io_uring_cq {
	unsigned *khead;
	unsigned *ktail;
	unsigned *kring_mask;
	unsigned *kring_entries;
	unsigned *koverflow;
	struct io_uring_cqe *cqes;

	size_t ring_sz;
};

struct io_uring {
	struct io_uring_sq sq;
	struct io_uring_cq cq;
	int ring_fd;
};

/*
 * System calls
 */
extern int io_uring_setup(unsigned entries, struct io_uring_params *p);
extern int io_uring_enter(unsigned fd, unsigned to_submit,
	unsigned min_complete, unsigned flags);
extern int io_uring_register(int fd, unsigned int opcode, void *arg);

/*
 * Library interface
 */
extern int io_uring_queue_init(unsigned entries, struct io_uring *ring,
	unsigned flags);
extern void io_uring_queue_exit(struct io_uring *ring);
extern int io_uring_get_completion(struct io_uring *ring,
	struct io_uring_cqe **cqe_ptr);
extern int io_uring_wait_completion(struct io_uring *ring,
	struct io_uring_cqe **cqe_ptr);
extern int io_uring_submit(struct io_uring *ring);
extern struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring);

/*
 * Command prep helpers
 */
static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data)
{
	sqe->user_data = (unsigned long) data;
}

static inline void io_uring_prep_readv(struct io_uring_sqe *sqe, int fd,
				       struct iovec *iovecs, unsigned nr_vecs,
				       off_t offset)
{
	memset(sqe, 0, sizeof(*sqe));
	sqe->opcode = IORING_OP_READV;
	sqe->fd = fd;
	sqe->off = offset;
	sqe->addr = (unsigned long) iovecs;
	sqe->len = nr_vecs;
}

static inline void io_uring_prep_writev(struct io_uring_sqe *sqe, int fd,
				        struct iovec *iovecs, unsigned nr_vecs,
					off_t offset)
{
	memset(sqe, 0, sizeof(*sqe));
	sqe->opcode = IORING_OP_WRITEV;
	sqe->fd = fd;
	sqe->off = offset;
	sqe->addr = (unsigned long) iovecs;
	sqe->len = nr_vecs;
}

static inline void io_uring_prep_poll(struct io_uring_sqe *sqe, int fd,
				      short poll_mask)
{
	memset(sqe, 0, sizeof(*sqe));
	sqe->opcode = IORING_OP_POLL;
	sqe->fd = fd;
	sqe->poll_events = poll_mask;
}

static inline void io_uring_prep_poll_cancel(struct io_uring_sqe *sqe,
					     void *user_data)
{
	memset(sqe, 0, sizeof(*sqe));
	sqe->opcode = IORING_OP_POLL_CANCEL;
	sqe->addr = (unsigned long) user_data;
}

#endif