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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 #ifdef __cplusplus
15 extern "C" {
16 #endif
17 
18 /*
19  * IO submission data structure (Submission Queue Entry)
20  */
21 struct io_uring_sqe {
22 	__u8	opcode;		/* type of operation for this sqe */
23 	__u8	flags;		/* IOSQE_ flags */
24 	__u16	ioprio;		/* ioprio for the request */
25 	__s32	fd;		/* file descriptor to do IO on */
26 	union {
27 		__u64	off;	/* offset into file */
28 		__u64	addr2;
29 	};
30 	union {
31 		__u64	addr;	/* pointer to buffer or iovecs */
32 		__u64	splice_off_in;
33 	};
34 	__u32	len;		/* buffer size or number of iovecs */
35 	union {
36 		__kernel_rwf_t	rw_flags;
37 		__u32		fsync_flags;
38 		__u16		poll_events;	/* compatibility */
39 		__u32		poll32_events;	/* word-reversed for BE */
40 		__u32		sync_range_flags;
41 		__u32		msg_flags;
42 		__u32		timeout_flags;
43 		__u32		accept_flags;
44 		__u32		cancel_flags;
45 		__u32		open_flags;
46 		__u32		statx_flags;
47 		__u32		fadvise_advice;
48 		__u32		splice_flags;
49 		__u32		rename_flags;
50 		__u32		unlink_flags;
51 		__u32		hardlink_flags;
52 	};
53 	__u64	user_data;	/* data to be passed back at completion time */
54 	union {
55 		struct {
56 			/* pack this to avoid bogus arm OABI complaints */
57 			union {
58 				/* index into fixed buffers, if used */
59 				__u16	buf_index;
60 				/* for grouped buffer selection */
61 				__u16	buf_group;
62 			} __attribute__((packed));
63 			/* personality to use, if used */
64 			__u16	personality;
65 			__s32	splice_fd_in;
66 		};
67 		__u64	__pad2[3];
68 	};
69 };
70 
71 enum {
72 	IOSQE_FIXED_FILE_BIT,
73 	IOSQE_IO_DRAIN_BIT,
74 	IOSQE_IO_LINK_BIT,
75 	IOSQE_IO_HARDLINK_BIT,
76 	IOSQE_ASYNC_BIT,
77 	IOSQE_BUFFER_SELECT_BIT,
78 };
79 
80 /*
81  * sqe->flags
82  */
83 /* use fixed fileset */
84 #define IOSQE_FIXED_FILE	(1U << IOSQE_FIXED_FILE_BIT)
85 /* issue after inflight IO */
86 #define IOSQE_IO_DRAIN		(1U << IOSQE_IO_DRAIN_BIT)
87 /* links next sqe */
88 #define IOSQE_IO_LINK		(1U << IOSQE_IO_LINK_BIT)
89 /* like LINK, but stronger */
90 #define IOSQE_IO_HARDLINK	(1U << IOSQE_IO_HARDLINK_BIT)
91 /* always go async */
92 #define IOSQE_ASYNC		(1U << IOSQE_ASYNC_BIT)
93 /* select buffer from sqe->buf_group */
94 #define IOSQE_BUFFER_SELECT	(1U << IOSQE_BUFFER_SELECT_BIT)
95 
96 /*
97  * io_uring_setup() flags
98  */
99 #define IORING_SETUP_IOPOLL	(1U << 0)	/* io_context is polled */
100 #define IORING_SETUP_SQPOLL	(1U << 1)	/* SQ poll thread */
101 #define IORING_SETUP_SQ_AFF	(1U << 2)	/* sq_thread_cpu is valid */
102 #define IORING_SETUP_CQSIZE	(1U << 3)	/* app defines CQ size */
103 #define IORING_SETUP_CLAMP	(1U << 4)	/* clamp SQ/CQ ring sizes */
104 #define IORING_SETUP_ATTACH_WQ	(1U << 5)	/* attach to existing wq */
105 #define IORING_SETUP_R_DISABLED	(1U << 6)	/* start with ring disabled */
106 
107 enum {
108 	IORING_OP_NOP,
109 	IORING_OP_READV,
110 	IORING_OP_WRITEV,
111 	IORING_OP_FSYNC,
112 	IORING_OP_READ_FIXED,
113 	IORING_OP_WRITE_FIXED,
114 	IORING_OP_POLL_ADD,
115 	IORING_OP_POLL_REMOVE,
116 	IORING_OP_SYNC_FILE_RANGE,
117 	IORING_OP_SENDMSG,
118 	IORING_OP_RECVMSG,
119 	IORING_OP_TIMEOUT,
120 	IORING_OP_TIMEOUT_REMOVE,
121 	IORING_OP_ACCEPT,
122 	IORING_OP_ASYNC_CANCEL,
123 	IORING_OP_LINK_TIMEOUT,
124 	IORING_OP_CONNECT,
125 	IORING_OP_FALLOCATE,
126 	IORING_OP_OPENAT,
127 	IORING_OP_CLOSE,
128 	IORING_OP_FILES_UPDATE,
129 	IORING_OP_STATX,
130 	IORING_OP_READ,
131 	IORING_OP_WRITE,
132 	IORING_OP_FADVISE,
133 	IORING_OP_MADVISE,
134 	IORING_OP_SEND,
135 	IORING_OP_RECV,
136 	IORING_OP_OPENAT2,
137 	IORING_OP_EPOLL_CTL,
138 	IORING_OP_SPLICE,
139 	IORING_OP_PROVIDE_BUFFERS,
140 	IORING_OP_REMOVE_BUFFERS,
141 	IORING_OP_TEE,
142 	IORING_OP_SHUTDOWN,
143 	IORING_OP_RENAMEAT,
144 	IORING_OP_UNLINKAT,
145 	IORING_OP_MKDIRAT,
146 	IORING_OP_SYMLINKAT,
147 	IORING_OP_LINKAT,
148 
149 	/* this goes last, obviously */
150 	IORING_OP_LAST,
151 };
152 
153 /*
154  * sqe->fsync_flags
155  */
156 #define IORING_FSYNC_DATASYNC	(1U << 0)
157 
158 /*
159  * sqe->timeout_flags
160  */
161 #define IORING_TIMEOUT_ABS	(1U << 0)
162 #define IORING_TIMEOUT_UPDATE	(1U << 1)
163 
164 /*
165  * sqe->splice_flags
166  * extends splice(2) flags
167  */
168 #define SPLICE_F_FD_IN_FIXED	(1U << 31) /* the last bit of __u32 */
169 
170 /*
171  * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
172  * command flags for POLL_ADD are stored in sqe->len.
173  *
174  * IORING_POLL_ADD_MULTI	Multishot poll. Sets IORING_CQE_F_MORE if
175  *				the poll handler will continue to report
176  *				CQEs on behalf of the same SQE.
177  *
178  * IORING_POLL_UPDATE		Update existing poll request, matching
179  *				sqe->addr as the old user_data field.
180  */
181 #define IORING_POLL_ADD_MULTI	(1U << 0)
182 #define IORING_POLL_UPDATE_EVENTS	(1U << 1)
183 #define IORING_POLL_UPDATE_USER_DATA	(1U << 2)
184 
185 /*
186  * IO completion data structure (Completion Queue Entry)
187  */
188 struct io_uring_cqe {
189 	__u64	user_data;	/* sqe->data submission passed back */
190 	__s32	res;		/* result code for this event */
191 	__u32	flags;
192 };
193 
194 /*
195  * cqe->flags
196  *
197  * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID
198  * IORING_CQE_F_MORE	If set, parent SQE will generate more CQE entries
199  */
200 #define IORING_CQE_F_BUFFER		(1U << 0)
201 #define IORING_CQE_F_MORE		(1U << 1)
202 
203 enum {
204 	IORING_CQE_BUFFER_SHIFT		= 16,
205 };
206 
207 /*
208  * Magic offsets for the application to mmap the data it needs
209  */
210 #define IORING_OFF_SQ_RING		0ULL
211 #define IORING_OFF_CQ_RING		0x8000000ULL
212 #define IORING_OFF_SQES			0x10000000ULL
213 
214 /*
215  * Filled with the offset for mmap(2)
216  */
217 struct io_sqring_offsets {
218 	__u32 head;
219 	__u32 tail;
220 	__u32 ring_mask;
221 	__u32 ring_entries;
222 	__u32 flags;
223 	__u32 dropped;
224 	__u32 array;
225 	__u32 resv1;
226 	__u64 resv2;
227 };
228 
229 /*
230  * sq_ring->flags
231  */
232 #define IORING_SQ_NEED_WAKEUP	(1U << 0) /* needs io_uring_enter wakeup */
233 #define IORING_SQ_CQ_OVERFLOW	(1U << 1) /* CQ ring is overflown */
234 
235 struct io_cqring_offsets {
236 	__u32 head;
237 	__u32 tail;
238 	__u32 ring_mask;
239 	__u32 ring_entries;
240 	__u32 overflow;
241 	__u32 cqes;
242 	__u32 flags;
243 	__u32 resv1;
244 	__u64 resv2;
245 };
246 
247 /*
248  * cq_ring->flags
249  */
250 
251 /* disable eventfd notifications */
252 #define IORING_CQ_EVENTFD_DISABLED	(1U << 0)
253 
254 /*
255  * io_uring_enter(2) flags
256  */
257 #define IORING_ENTER_GETEVENTS	(1U << 0)
258 #define IORING_ENTER_SQ_WAKEUP	(1U << 1)
259 #define IORING_ENTER_SQ_WAIT	(1U << 2)
260 #define IORING_ENTER_EXT_ARG	(1U << 3)
261 
262 /*
263  * Passed in for io_uring_setup(2). Copied back with updated info on success
264  */
265 struct io_uring_params {
266 	__u32 sq_entries;
267 	__u32 cq_entries;
268 	__u32 flags;
269 	__u32 sq_thread_cpu;
270 	__u32 sq_thread_idle;
271 	__u32 features;
272 	__u32 wq_fd;
273 	__u32 resv[3];
274 	struct io_sqring_offsets sq_off;
275 	struct io_cqring_offsets cq_off;
276 };
277 
278 /*
279  * io_uring_params->features flags
280  */
281 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
282 #define IORING_FEAT_NODROP		(1U << 1)
283 #define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
284 #define IORING_FEAT_RW_CUR_POS		(1U << 3)
285 #define IORING_FEAT_CUR_PERSONALITY	(1U << 4)
286 #define IORING_FEAT_FAST_POLL		(1U << 5)
287 #define IORING_FEAT_POLL_32BITS 	(1U << 6)
288 #define IORING_FEAT_SQPOLL_NONFIXED	(1U << 7)
289 #define IORING_FEAT_EXT_ARG		(1U << 8)
290 #define IORING_FEAT_NATIVE_WORKERS	(1U << 9)
291 #define IORING_FEAT_RSRC_TAGS		(1U << 10)
292 
293 /*
294  * io_uring_register(2) opcodes and arguments
295  */
296 enum {
297 	IORING_REGISTER_BUFFERS			= 0,
298 	IORING_UNREGISTER_BUFFERS		= 1,
299 	IORING_REGISTER_FILES			= 2,
300 	IORING_UNREGISTER_FILES			= 3,
301 	IORING_REGISTER_EVENTFD			= 4,
302 	IORING_UNREGISTER_EVENTFD		= 5,
303 	IORING_REGISTER_FILES_UPDATE		= 6,
304 	IORING_REGISTER_EVENTFD_ASYNC		= 7,
305 	IORING_REGISTER_PROBE			= 8,
306 	IORING_REGISTER_PERSONALITY		= 9,
307 	IORING_UNREGISTER_PERSONALITY		= 10,
308 	IORING_REGISTER_RESTRICTIONS		= 11,
309 	IORING_REGISTER_ENABLE_RINGS		= 12,
310 
311 	/* extended with tagging */
312 	IORING_REGISTER_FILES2			= 13,
313 	IORING_REGISTER_FILES_UPDATE2		= 14,
314 	IORING_REGISTER_BUFFERS2		= 15,
315 	IORING_REGISTER_BUFFERS_UPDATE		= 16,
316 
317 	/* this goes last */
318 	IORING_REGISTER_LAST
319 };
320 
321 /* deprecated, see struct io_uring_rsrc_update */
322 struct io_uring_files_update {
323 	__u32 offset;
324 	__u32 resv;
325 	__aligned_u64 /* __s32 * */ fds;
326 };
327 
328 struct io_uring_rsrc_register {
329 	__u32 nr;
330 	__u32 resv;
331 	__u64 resv2;
332 	__aligned_u64 data;
333 	__aligned_u64 tags;
334 };
335 
336 struct io_uring_rsrc_update {
337 	__u32 offset;
338 	__u32 resv;
339 	__aligned_u64 data;
340 };
341 
342 struct io_uring_rsrc_update2 {
343 	__u32 offset;
344 	__u32 resv;
345 	__aligned_u64 data;
346 	__aligned_u64 tags;
347 	__u32 nr;
348 	__u32 resv2;
349 };
350 
351 /* Skip updating fd indexes set to this value in the fd table */
352 #define IORING_REGISTER_FILES_SKIP	(-2)
353 
354 #define IO_URING_OP_SUPPORTED	(1U << 0)
355 
356 struct io_uring_probe_op {
357 	__u8 op;
358 	__u8 resv;
359 	__u16 flags;	/* IO_URING_OP_* flags */
360 	__u32 resv2;
361 };
362 
363 struct io_uring_probe {
364 	__u8 last_op;	/* last opcode supported */
365 	__u8 ops_len;	/* length of ops[] array below */
366 	__u16 resv;
367 	__u32 resv2[3];
368 	struct io_uring_probe_op ops[];
369 };
370 
371 struct io_uring_restriction {
372 	__u16 opcode;
373 	union {
374 		__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
375 		__u8 sqe_op;      /* IORING_RESTRICTION_SQE_OP */
376 		__u8 sqe_flags;   /* IORING_RESTRICTION_SQE_FLAGS_* */
377 	};
378 	__u8 resv;
379 	__u32 resv2[3];
380 };
381 
382 /*
383  * io_uring_restriction->opcode values
384  */
385 enum {
386 	/* Allow an io_uring_register(2) opcode */
387 	IORING_RESTRICTION_REGISTER_OP		= 0,
388 
389 	/* Allow an sqe opcode */
390 	IORING_RESTRICTION_SQE_OP		= 1,
391 
392 	/* Allow sqe flags */
393 	IORING_RESTRICTION_SQE_FLAGS_ALLOWED	= 2,
394 
395 	/* Require sqe flags (these flags must be set on each submission) */
396 	IORING_RESTRICTION_SQE_FLAGS_REQUIRED	= 3,
397 
398 	IORING_RESTRICTION_LAST
399 };
400 
401 struct io_uring_getevents_arg {
402 	__u64	sigmask;
403 	__u32	sigmask_sz;
404 	__u32	pad;
405 	__u64	ts;
406 };
407 
408 #ifdef __cplusplus
409 }
410 #endif
411 
412 #endif
413