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