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1 /* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
2 /*
3  * Header file for the io_uring interface.
4  *
5  * Copyright (C) 2019 Jens Axboe
6  * Copyright (C) 2019 Christoph Hellwig
7  */
8 #ifndef LINUX_IO_URING_H
9 #define LINUX_IO_URING_H
10 
11 #include <linux/fs.h>
12 #include <linux/types.h>
13 
14 /*
15  * IO submission data structure (Submission Queue Entry)
16  */
17 struct io_uring_sqe {
18 	__u8	opcode;		/* type of operation for this sqe */
19 	__u8	flags;		/* IOSQE_ flags */
20 	__u16	ioprio;		/* ioprio for the request */
21 	__s32	fd;		/* file descriptor to do IO on */
22 	union {
23 		__u64	off;	/* offset into file */
24 		__u64	addr2;
25 	};
26 	union {
27 		__u64	addr;	/* pointer to buffer or iovecs */
28 		__u64	splice_off_in;
29 	};
30 	__u32	len;		/* buffer size or number of iovecs */
31 	union {
32 		__kernel_rwf_t	rw_flags;
33 		__u32		fsync_flags;
34 		__u16		poll_events;	/* compatibility */
35 		__u32		poll32_events;	/* word-reversed for BE */
36 		__u32		sync_range_flags;
37 		__u32		msg_flags;
38 		__u32		timeout_flags;
39 		__u32		accept_flags;
40 		__u32		cancel_flags;
41 		__u32		open_flags;
42 		__u32		statx_flags;
43 		__u32		fadvise_advice;
44 		__u32		splice_flags;
45 		__u32		rename_flags;
46 		__u32		unlink_flags;
47 	};
48 	__u64	user_data;	/* data to be passed back at completion time */
49 	union {
50 		struct {
51 			/* pack this to avoid bogus arm OABI complaints */
52 			union {
53 				/* index into fixed buffers, if used */
54 				__u16	buf_index;
55 				/* for grouped buffer selection */
56 				__u16	buf_group;
57 			} __attribute__((packed));
58 			/* personality to use, if used */
59 			__u16	personality;
60 			__s32	splice_fd_in;
61 		};
62 		__u64	__pad2[3];
63 	};
64 };
65 
66 enum {
67 	IOSQE_FIXED_FILE_BIT,
68 	IOSQE_IO_DRAIN_BIT,
69 	IOSQE_IO_LINK_BIT,
70 	IOSQE_IO_HARDLINK_BIT,
71 	IOSQE_ASYNC_BIT,
72 	IOSQE_BUFFER_SELECT_BIT,
73 };
74 
75 /*
76  * sqe->flags
77  */
78 /* use fixed fileset */
79 #define IOSQE_FIXED_FILE	(1U << IOSQE_FIXED_FILE_BIT)
80 /* issue after inflight IO */
81 #define IOSQE_IO_DRAIN		(1U << IOSQE_IO_DRAIN_BIT)
82 /* links next sqe */
83 #define IOSQE_IO_LINK		(1U << IOSQE_IO_LINK_BIT)
84 /* like LINK, but stronger */
85 #define IOSQE_IO_HARDLINK	(1U << IOSQE_IO_HARDLINK_BIT)
86 /* always go async */
87 #define IOSQE_ASYNC		(1U << IOSQE_ASYNC_BIT)
88 /* select buffer from sqe->buf_group */
89 #define IOSQE_BUFFER_SELECT	(1U << IOSQE_BUFFER_SELECT_BIT)
90 
91 /*
92  * io_uring_setup() flags
93  */
94 #define IORING_SETUP_IOPOLL	(1U << 0)	/* io_context is polled */
95 #define IORING_SETUP_SQPOLL	(1U << 1)	/* SQ poll thread */
96 #define IORING_SETUP_SQ_AFF	(1U << 2)	/* sq_thread_cpu is valid */
97 #define IORING_SETUP_CQSIZE	(1U << 3)	/* app defines CQ size */
98 #define IORING_SETUP_CLAMP	(1U << 4)	/* clamp SQ/CQ ring sizes */
99 #define IORING_SETUP_ATTACH_WQ	(1U << 5)	/* attach to existing wq */
100 #define IORING_SETUP_R_DISABLED	(1U << 6)	/* start with ring disabled */
101 
102 enum {
103 	IORING_OP_NOP,
104 	IORING_OP_READV,
105 	IORING_OP_WRITEV,
106 	IORING_OP_FSYNC,
107 	IORING_OP_READ_FIXED,
108 	IORING_OP_WRITE_FIXED,
109 	IORING_OP_POLL_ADD,
110 	IORING_OP_POLL_REMOVE,
111 	IORING_OP_SYNC_FILE_RANGE,
112 	IORING_OP_SENDMSG,
113 	IORING_OP_RECVMSG,
114 	IORING_OP_TIMEOUT,
115 	IORING_OP_TIMEOUT_REMOVE,
116 	IORING_OP_ACCEPT,
117 	IORING_OP_ASYNC_CANCEL,
118 	IORING_OP_LINK_TIMEOUT,
119 	IORING_OP_CONNECT,
120 	IORING_OP_FALLOCATE,
121 	IORING_OP_OPENAT,
122 	IORING_OP_CLOSE,
123 	IORING_OP_FILES_UPDATE,
124 	IORING_OP_STATX,
125 	IORING_OP_READ,
126 	IORING_OP_WRITE,
127 	IORING_OP_FADVISE,
128 	IORING_OP_MADVISE,
129 	IORING_OP_SEND,
130 	IORING_OP_RECV,
131 	IORING_OP_OPENAT2,
132 	IORING_OP_EPOLL_CTL,
133 	IORING_OP_SPLICE,
134 	IORING_OP_PROVIDE_BUFFERS,
135 	IORING_OP_REMOVE_BUFFERS,
136 	IORING_OP_TEE,
137 	IORING_OP_SHUTDOWN,
138 	IORING_OP_RENAMEAT,
139 	IORING_OP_UNLINKAT,
140 
141 	/* this goes last, obviously */
142 	IORING_OP_LAST,
143 };
144 
145 /*
146  * sqe->fsync_flags
147  */
148 #define IORING_FSYNC_DATASYNC	(1U << 0)
149 
150 /*
151  * sqe->timeout_flags
152  */
153 #define IORING_TIMEOUT_ABS	(1U << 0)
154 #define IORING_TIMEOUT_UPDATE	(1U << 1)
155 
156 /*
157  * sqe->splice_flags
158  * extends splice(2) flags
159  */
160 #define SPLICE_F_FD_IN_FIXED	(1U << 31) /* the last bit of __u32 */
161 
162 /*
163  * IO completion data structure (Completion Queue Entry)
164  */
165 struct io_uring_cqe {
166 	__u64	user_data;	/* sqe->data submission passed back */
167 	__s32	res;		/* result code for this event */
168 	__u32	flags;
169 };
170 
171 /*
172  * cqe->flags
173  *
174  * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID
175  */
176 #define IORING_CQE_F_BUFFER		(1U << 0)
177 
178 enum {
179 	IORING_CQE_BUFFER_SHIFT		= 16,
180 };
181 
182 /*
183  * Magic offsets for the application to mmap the data it needs
184  */
185 #define IORING_OFF_SQ_RING		0ULL
186 #define IORING_OFF_CQ_RING		0x8000000ULL
187 #define IORING_OFF_SQES			0x10000000ULL
188 
189 /*
190  * Filled with the offset for mmap(2)
191  */
192 struct io_sqring_offsets {
193 	__u32 head;
194 	__u32 tail;
195 	__u32 ring_mask;
196 	__u32 ring_entries;
197 	__u32 flags;
198 	__u32 dropped;
199 	__u32 array;
200 	__u32 resv1;
201 	__u64 resv2;
202 };
203 
204 /*
205  * sq_ring->flags
206  */
207 #define IORING_SQ_NEED_WAKEUP	(1U << 0) /* needs io_uring_enter wakeup */
208 #define IORING_SQ_CQ_OVERFLOW	(1U << 1) /* CQ ring is overflown */
209 
210 struct io_cqring_offsets {
211 	__u32 head;
212 	__u32 tail;
213 	__u32 ring_mask;
214 	__u32 ring_entries;
215 	__u32 overflow;
216 	__u32 cqes;
217 	__u32 flags;
218 	__u32 resv1;
219 	__u64 resv2;
220 };
221 
222 /*
223  * cq_ring->flags
224  */
225 
226 /* disable eventfd notifications */
227 #define IORING_CQ_EVENTFD_DISABLED	(1U << 0)
228 
229 /*
230  * io_uring_enter(2) flags
231  */
232 #define IORING_ENTER_GETEVENTS	(1U << 0)
233 #define IORING_ENTER_SQ_WAKEUP	(1U << 1)
234 #define IORING_ENTER_SQ_WAIT	(1U << 2)
235 #define IORING_ENTER_EXT_ARG	(1U << 3)
236 
237 /*
238  * Passed in for io_uring_setup(2). Copied back with updated info on success
239  */
240 struct io_uring_params {
241 	__u32 sq_entries;
242 	__u32 cq_entries;
243 	__u32 flags;
244 	__u32 sq_thread_cpu;
245 	__u32 sq_thread_idle;
246 	__u32 features;
247 	__u32 wq_fd;
248 	__u32 resv[3];
249 	struct io_sqring_offsets sq_off;
250 	struct io_cqring_offsets cq_off;
251 };
252 
253 /*
254  * io_uring_params->features flags
255  */
256 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
257 #define IORING_FEAT_NODROP		(1U << 1)
258 #define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
259 #define IORING_FEAT_RW_CUR_POS		(1U << 3)
260 #define IORING_FEAT_CUR_PERSONALITY	(1U << 4)
261 #define IORING_FEAT_FAST_POLL		(1U << 5)
262 #define IORING_FEAT_POLL_32BITS 	(1U << 6)
263 #define IORING_FEAT_SQPOLL_NONFIXED	(1U << 7)
264 #define IORING_FEAT_EXT_ARG		(1U << 8)
265 #define IORING_FEAT_NATIVE_WORKERS	(1U << 9)
266 
267 /*
268  * io_uring_register(2) opcodes and arguments
269  */
270 enum {
271 	IORING_REGISTER_BUFFERS			= 0,
272 	IORING_UNREGISTER_BUFFERS		= 1,
273 	IORING_REGISTER_FILES			= 2,
274 	IORING_UNREGISTER_FILES			= 3,
275 	IORING_REGISTER_EVENTFD			= 4,
276 	IORING_UNREGISTER_EVENTFD		= 5,
277 	IORING_REGISTER_FILES_UPDATE		= 6,
278 	IORING_REGISTER_EVENTFD_ASYNC		= 7,
279 	IORING_REGISTER_PROBE			= 8,
280 	IORING_REGISTER_PERSONALITY		= 9,
281 	IORING_UNREGISTER_PERSONALITY		= 10,
282 	IORING_REGISTER_RESTRICTIONS		= 11,
283 	IORING_REGISTER_ENABLE_RINGS		= 12,
284 
285 	/* this goes last */
286 	IORING_REGISTER_LAST
287 };
288 
289 /* deprecated, see struct io_uring_rsrc_update */
290 struct io_uring_files_update {
291 	__u32 offset;
292 	__u32 resv;
293 	__aligned_u64 /* __s32 * */ fds;
294 };
295 
296 struct io_uring_rsrc_update {
297 	__u32 offset;
298 	__u32 resv;
299 	__aligned_u64 data;
300 };
301 
302 /* Skip updating fd indexes set to this value in the fd table */
303 #define IORING_REGISTER_FILES_SKIP	(-2)
304 
305 #define IO_URING_OP_SUPPORTED	(1U << 0)
306 
307 struct io_uring_probe_op {
308 	__u8 op;
309 	__u8 resv;
310 	__u16 flags;	/* IO_URING_OP_* flags */
311 	__u32 resv2;
312 };
313 
314 struct io_uring_probe {
315 	__u8 last_op;	/* last opcode supported */
316 	__u8 ops_len;	/* length of ops[] array below */
317 	__u16 resv;
318 	__u32 resv2[3];
319 	struct io_uring_probe_op ops[0];
320 };
321 
322 struct io_uring_restriction {
323 	__u16 opcode;
324 	union {
325 		__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
326 		__u8 sqe_op;      /* IORING_RESTRICTION_SQE_OP */
327 		__u8 sqe_flags;   /* IORING_RESTRICTION_SQE_FLAGS_* */
328 	};
329 	__u8 resv;
330 	__u32 resv2[3];
331 };
332 
333 /*
334  * io_uring_restriction->opcode values
335  */
336 enum {
337 	/* Allow an io_uring_register(2) opcode */
338 	IORING_RESTRICTION_REGISTER_OP		= 0,
339 
340 	/* Allow an sqe opcode */
341 	IORING_RESTRICTION_SQE_OP		= 1,
342 
343 	/* Allow sqe flags */
344 	IORING_RESTRICTION_SQE_FLAGS_ALLOWED	= 2,
345 
346 	/* Require sqe flags (these flags must be set on each submission) */
347 	IORING_RESTRICTION_SQE_FLAGS_REQUIRED	= 3,
348 
349 	IORING_RESTRICTION_LAST
350 };
351 
352 struct io_uring_getevents_arg {
353 	__u64	sigmask;
354 	__u32	sigmask_sz;
355 	__u32	pad;
356 	__u64	ts;
357 };
358 
359 #endif
360