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 */
io_uring_cqe_seen(struct io_uring * ring,struct io_uring_cqe * cqe)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 */
io_uring_sqe_set_data(struct io_uring_sqe * sqe,void * data)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
io_uring_cqe_get_data(struct io_uring_cqe * cqe)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
io_uring_prep_rw(int op,struct io_uring_sqe * sqe,int fd,const void * addr,unsigned len,off_t offset)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
io_uring_prep_readv(struct io_uring_sqe * sqe,int fd,const struct iovec * iovecs,unsigned nr_vecs,off_t offset)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
io_uring_prep_read_fixed(struct io_uring_sqe * sqe,int fd,void * buf,unsigned nbytes,off_t offset)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
io_uring_prep_writev(struct io_uring_sqe * sqe,int fd,const struct iovec * iovecs,unsigned nr_vecs,off_t offset)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
io_uring_prep_write_fixed(struct io_uring_sqe * sqe,int fd,const void * buf,unsigned nbytes,off_t offset)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
io_uring_prep_poll_add(struct io_uring_sqe * sqe,int fd,unsigned poll_mask)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
io_uring_prep_poll_remove(struct io_uring_sqe * sqe,void * user_data)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
io_uring_prep_fsync(struct io_uring_sqe * sqe,int fd,unsigned fsync_flags)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
io_uring_prep_nop(struct io_uring_sqe * sqe)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
188