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  * this file is shared with liburing and that has to autodetect
15  * if linux/time_types.h is available or not, it can
16  * define UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
17  * if linux/time_types.h is not available
18  */
19 #ifndef UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
20 #include <linux/time_types.h>
21 #endif
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 /*
28  * IO submission data structure (Submission Queue Entry)
29  */
30 struct io_uring_sqe {
31 	__u8	opcode;		/* type of operation for this sqe */
32 	__u8	flags;		/* IOSQE_ flags */
33 	__u16	ioprio;		/* ioprio for the request */
34 	__s32	fd;		/* file descriptor to do IO on */
35 	union {
36 		__u64	off;	/* offset into file */
37 		__u64	addr2;
38 		struct {
39 			__u32	cmd_op;
40 			__u32	__pad1;
41 		};
42 	};
43 	union {
44 		__u64	addr;	/* pointer to buffer or iovecs */
45 		__u64	splice_off_in;
46 		struct {
47 			__u32	level;
48 			__u32	optname;
49 		};
50 	};
51 	__u32	len;		/* buffer size or number of iovecs */
52 	union {
53 		__kernel_rwf_t	rw_flags;
54 		__u32		fsync_flags;
55 		__u16		poll_events;	/* compatibility */
56 		__u32		poll32_events;	/* word-reversed for BE */
57 		__u32		sync_range_flags;
58 		__u32		msg_flags;
59 		__u32		timeout_flags;
60 		__u32		accept_flags;
61 		__u32		cancel_flags;
62 		__u32		open_flags;
63 		__u32		statx_flags;
64 		__u32		fadvise_advice;
65 		__u32		splice_flags;
66 		__u32		rename_flags;
67 		__u32		unlink_flags;
68 		__u32		hardlink_flags;
69 		__u32		xattr_flags;
70 		__u32		msg_ring_flags;
71 		__u32		uring_cmd_flags;
72 		__u32		waitid_flags;
73 		__u32		futex_flags;
74 		__u32		install_fd_flags;
75 	};
76 	__u64	user_data;	/* data to be passed back at completion time */
77 	/* pack this to avoid bogus arm OABI complaints */
78 	union {
79 		/* index into fixed buffers, if used */
80 		__u16	buf_index;
81 		/* for grouped buffer selection */
82 		__u16	buf_group;
83 	} __attribute__((packed));
84 	/* personality to use, if used */
85 	__u16	personality;
86 	union {
87 		__s32	splice_fd_in;
88 		__u32	file_index;
89 		__u32	optlen;
90 		struct {
91 			__u16	addr_len;
92 			__u16	__pad3[1];
93 		};
94 	};
95 	union {
96 		struct {
97 			__u64	addr3;
98 			__u64	__pad2[1];
99 		};
100 		__u64	optval;
101 		/*
102 		 * If the ring is initialized with IORING_SETUP_SQE128, then
103 		 * this field is used for 80 bytes of arbitrary command data
104 		 */
105 		__u8	cmd[0];
106 	};
107 };
108 
109 /*
110  * If sqe->file_index is set to this for opcodes that instantiate a new
111  * direct descriptor (like openat/openat2/accept), then io_uring will allocate
112  * an available direct descriptor instead of having the application pass one
113  * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE
114  * if the space is full.
115  */
116 #define IORING_FILE_INDEX_ALLOC		(~0U)
117 
118 enum {
119 	IOSQE_FIXED_FILE_BIT,
120 	IOSQE_IO_DRAIN_BIT,
121 	IOSQE_IO_LINK_BIT,
122 	IOSQE_IO_HARDLINK_BIT,
123 	IOSQE_ASYNC_BIT,
124 	IOSQE_BUFFER_SELECT_BIT,
125 	IOSQE_CQE_SKIP_SUCCESS_BIT,
126 };
127 
128 /*
129  * sqe->flags
130  */
131 /* use fixed fileset */
132 #define IOSQE_FIXED_FILE	(1U << IOSQE_FIXED_FILE_BIT)
133 /* issue after inflight IO */
134 #define IOSQE_IO_DRAIN		(1U << IOSQE_IO_DRAIN_BIT)
135 /* links next sqe */
136 #define IOSQE_IO_LINK		(1U << IOSQE_IO_LINK_BIT)
137 /* like LINK, but stronger */
138 #define IOSQE_IO_HARDLINK	(1U << IOSQE_IO_HARDLINK_BIT)
139 /* always go async */
140 #define IOSQE_ASYNC		(1U << IOSQE_ASYNC_BIT)
141 /* select buffer from sqe->buf_group */
142 #define IOSQE_BUFFER_SELECT	(1U << IOSQE_BUFFER_SELECT_BIT)
143 /* don't post CQE if request succeeded */
144 #define IOSQE_CQE_SKIP_SUCCESS	(1U << IOSQE_CQE_SKIP_SUCCESS_BIT)
145 
146 /*
147  * io_uring_setup() flags
148  */
149 #define IORING_SETUP_IOPOLL	(1U << 0)	/* io_context is polled */
150 #define IORING_SETUP_SQPOLL	(1U << 1)	/* SQ poll thread */
151 #define IORING_SETUP_SQ_AFF	(1U << 2)	/* sq_thread_cpu is valid */
152 #define IORING_SETUP_CQSIZE	(1U << 3)	/* app defines CQ size */
153 #define IORING_SETUP_CLAMP	(1U << 4)	/* clamp SQ/CQ ring sizes */
154 #define IORING_SETUP_ATTACH_WQ	(1U << 5)	/* attach to existing wq */
155 #define IORING_SETUP_R_DISABLED	(1U << 6)	/* start with ring disabled */
156 #define IORING_SETUP_SUBMIT_ALL	(1U << 7)	/* continue submit on error */
157 /*
158  * Cooperative task running. When requests complete, they often require
159  * forcing the submitter to transition to the kernel to complete. If this
160  * flag is set, work will be done when the task transitions anyway, rather
161  * than force an inter-processor interrupt reschedule. This avoids interrupting
162  * a task running in userspace, and saves an IPI.
163  */
164 #define IORING_SETUP_COOP_TASKRUN	(1U << 8)
165 /*
166  * If COOP_TASKRUN is set, get notified if task work is available for
167  * running and a kernel transition would be needed to run it. This sets
168  * IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN.
169  */
170 #define IORING_SETUP_TASKRUN_FLAG	(1U << 9)
171 #define IORING_SETUP_SQE128		(1U << 10) /* SQEs are 128 byte */
172 #define IORING_SETUP_CQE32		(1U << 11) /* CQEs are 32 byte */
173 /*
174  * Only one task is allowed to submit requests
175  */
176 #define IORING_SETUP_SINGLE_ISSUER	(1U << 12)
177 
178 /*
179  * Defer running task work to get events.
180  * Rather than running bits of task work whenever the task transitions
181  * try to do it just before it is needed.
182  */
183 #define IORING_SETUP_DEFER_TASKRUN	(1U << 13)
184 
185 /*
186  * Application provides the memory for the rings
187  */
188 #define IORING_SETUP_NO_MMAP		(1U << 14)
189 
190 /*
191  * Register the ring fd in itself for use with
192  * IORING_REGISTER_USE_REGISTERED_RING; return a registered fd index rather
193  * than an fd.
194  */
195 #define IORING_SETUP_REGISTERED_FD_ONLY	(1U << 15)
196 
197 /*
198  * Removes indirection through the SQ index array.
199  */
200 #define IORING_SETUP_NO_SQARRAY		(1U << 16)
201 
202 enum io_uring_op {
203 	IORING_OP_NOP,
204 	IORING_OP_READV,
205 	IORING_OP_WRITEV,
206 	IORING_OP_FSYNC,
207 	IORING_OP_READ_FIXED,
208 	IORING_OP_WRITE_FIXED,
209 	IORING_OP_POLL_ADD,
210 	IORING_OP_POLL_REMOVE,
211 	IORING_OP_SYNC_FILE_RANGE,
212 	IORING_OP_SENDMSG,
213 	IORING_OP_RECVMSG,
214 	IORING_OP_TIMEOUT,
215 	IORING_OP_TIMEOUT_REMOVE,
216 	IORING_OP_ACCEPT,
217 	IORING_OP_ASYNC_CANCEL,
218 	IORING_OP_LINK_TIMEOUT,
219 	IORING_OP_CONNECT,
220 	IORING_OP_FALLOCATE,
221 	IORING_OP_OPENAT,
222 	IORING_OP_CLOSE,
223 	IORING_OP_FILES_UPDATE,
224 	IORING_OP_STATX,
225 	IORING_OP_READ,
226 	IORING_OP_WRITE,
227 	IORING_OP_FADVISE,
228 	IORING_OP_MADVISE,
229 	IORING_OP_SEND,
230 	IORING_OP_RECV,
231 	IORING_OP_OPENAT2,
232 	IORING_OP_EPOLL_CTL,
233 	IORING_OP_SPLICE,
234 	IORING_OP_PROVIDE_BUFFERS,
235 	IORING_OP_REMOVE_BUFFERS,
236 	IORING_OP_TEE,
237 	IORING_OP_SHUTDOWN,
238 	IORING_OP_RENAMEAT,
239 	IORING_OP_UNLINKAT,
240 	IORING_OP_MKDIRAT,
241 	IORING_OP_SYMLINKAT,
242 	IORING_OP_LINKAT,
243 	IORING_OP_MSG_RING,
244 	IORING_OP_FSETXATTR,
245 	IORING_OP_SETXATTR,
246 	IORING_OP_FGETXATTR,
247 	IORING_OP_GETXATTR,
248 	IORING_OP_SOCKET,
249 	IORING_OP_URING_CMD,
250 	IORING_OP_SEND_ZC,
251 	IORING_OP_SENDMSG_ZC,
252 	IORING_OP_READ_MULTISHOT,
253 	IORING_OP_WAITID,
254 	IORING_OP_FUTEX_WAIT,
255 	IORING_OP_FUTEX_WAKE,
256 	IORING_OP_FUTEX_WAITV,
257 	IORING_OP_FIXED_FD_INSTALL,
258 
259 	/* this goes last, obviously */
260 	IORING_OP_LAST,
261 };
262 
263 /*
264  * sqe->uring_cmd_flags		top 8bits aren't available for userspace
265  * IORING_URING_CMD_FIXED	use registered buffer; pass this flag
266  *				along with setting sqe->buf_index.
267  */
268 #define IORING_URING_CMD_FIXED	(1U << 0)
269 #define IORING_URING_CMD_MASK	IORING_URING_CMD_FIXED
270 
271 
272 /*
273  * sqe->fsync_flags
274  */
275 #define IORING_FSYNC_DATASYNC	(1U << 0)
276 
277 /*
278  * sqe->timeout_flags
279  */
280 #define IORING_TIMEOUT_ABS		(1U << 0)
281 #define IORING_TIMEOUT_UPDATE		(1U << 1)
282 #define IORING_TIMEOUT_BOOTTIME		(1U << 2)
283 #define IORING_TIMEOUT_REALTIME		(1U << 3)
284 #define IORING_LINK_TIMEOUT_UPDATE	(1U << 4)
285 #define IORING_TIMEOUT_ETIME_SUCCESS	(1U << 5)
286 #define IORING_TIMEOUT_MULTISHOT	(1U << 6)
287 #define IORING_TIMEOUT_CLOCK_MASK	(IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
288 #define IORING_TIMEOUT_UPDATE_MASK	(IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
289 /*
290  * sqe->splice_flags
291  * extends splice(2) flags
292  */
293 #define SPLICE_F_FD_IN_FIXED	(1U << 31) /* the last bit of __u32 */
294 
295 /*
296  * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
297  * command flags for POLL_ADD are stored in sqe->len.
298  *
299  * IORING_POLL_ADD_MULTI	Multishot poll. Sets IORING_CQE_F_MORE if
300  *				the poll handler will continue to report
301  *				CQEs on behalf of the same SQE.
302  *
303  * IORING_POLL_UPDATE		Update existing poll request, matching
304  *				sqe->addr as the old user_data field.
305  *
306  * IORING_POLL_LEVEL		Level triggered poll.
307  */
308 #define IORING_POLL_ADD_MULTI	(1U << 0)
309 #define IORING_POLL_UPDATE_EVENTS	(1U << 1)
310 #define IORING_POLL_UPDATE_USER_DATA	(1U << 2)
311 #define IORING_POLL_ADD_LEVEL		(1U << 3)
312 
313 /*
314  * ASYNC_CANCEL flags.
315  *
316  * IORING_ASYNC_CANCEL_ALL	Cancel all requests that match the given key
317  * IORING_ASYNC_CANCEL_FD	Key off 'fd' for cancelation rather than the
318  *				request 'user_data'
319  * IORING_ASYNC_CANCEL_ANY	Match any request
320  * IORING_ASYNC_CANCEL_FD_FIXED	'fd' passed in is a fixed descriptor
321  * IORING_ASYNC_CANCEL_USERDATA	Match on user_data, default for no other key
322  * IORING_ASYNC_CANCEL_OP	Match request based on opcode
323  */
324 #define IORING_ASYNC_CANCEL_ALL	(1U << 0)
325 #define IORING_ASYNC_CANCEL_FD	(1U << 1)
326 #define IORING_ASYNC_CANCEL_ANY	(1U << 2)
327 #define IORING_ASYNC_CANCEL_FD_FIXED	(1U << 3)
328 #define IORING_ASYNC_CANCEL_USERDATA	(1U << 4)
329 #define IORING_ASYNC_CANCEL_OP	(1U << 5)
330 
331 /*
332  * send/sendmsg and recv/recvmsg flags (sqe->ioprio)
333  *
334  * IORING_RECVSEND_POLL_FIRST	If set, instead of first attempting to send
335  *				or receive and arm poll if that yields an
336  *				-EAGAIN result, arm poll upfront and skip
337  *				the initial transfer attempt.
338  *
339  * IORING_RECV_MULTISHOT	Multishot recv. Sets IORING_CQE_F_MORE if
340  *				the handler will continue to report
341  *				CQEs on behalf of the same SQE.
342  *
343  * IORING_RECVSEND_FIXED_BUF	Use registered buffers, the index is stored in
344  *				the buf_index field.
345  *
346  * IORING_SEND_ZC_REPORT_USAGE
347  *				If set, SEND[MSG]_ZC should report
348  *				the zerocopy usage in cqe.res
349  *				for the IORING_CQE_F_NOTIF cqe.
350  *				0 is reported if zerocopy was actually possible.
351  *				IORING_NOTIF_USAGE_ZC_COPIED if data was copied
352  *				(at least partially).
353  */
354 #define IORING_RECVSEND_POLL_FIRST	(1U << 0)
355 #define IORING_RECV_MULTISHOT		(1U << 1)
356 #define IORING_RECVSEND_FIXED_BUF	(1U << 2)
357 #define IORING_SEND_ZC_REPORT_USAGE	(1U << 3)
358 
359 /*
360  * cqe.res for IORING_CQE_F_NOTIF if
361  * IORING_SEND_ZC_REPORT_USAGE was requested
362  *
363  * It should be treated as a flag, all other
364  * bits of cqe.res should be treated as reserved!
365  */
366 #define IORING_NOTIF_USAGE_ZC_COPIED    (1U << 31)
367 
368 /*
369  * accept flags stored in sqe->ioprio
370  */
371 #define IORING_ACCEPT_MULTISHOT	(1U << 0)
372 
373 /*
374  * IORING_OP_MSG_RING command types, stored in sqe->addr
375  */
376 enum {
377 	IORING_MSG_DATA,	/* pass sqe->len as 'res' and off as user_data */
378 	IORING_MSG_SEND_FD,	/* send a registered fd to another ring */
379 };
380 
381 /*
382  * IORING_OP_MSG_RING flags (sqe->msg_ring_flags)
383  *
384  * IORING_MSG_RING_CQE_SKIP	Don't post a CQE to the target ring. Not
385  *				applicable for IORING_MSG_DATA, obviously.
386  */
387 #define IORING_MSG_RING_CQE_SKIP	(1U << 0)
388 /* Pass through the flags from sqe->file_index to cqe->flags */
389 #define IORING_MSG_RING_FLAGS_PASS	(1U << 1)
390 
391 /*
392  * IORING_OP_FIXED_FD_INSTALL flags (sqe->install_fd_flags)
393  *
394  * IORING_FIXED_FD_NO_CLOEXEC	Don't mark the fd as O_CLOEXEC
395  */
396 #define IORING_FIXED_FD_NO_CLOEXEC	(1U << 0)
397 
398 /*
399  * IO completion data structure (Completion Queue Entry)
400  */
401 struct io_uring_cqe {
402 	__u64	user_data;	/* sqe->data submission passed back */
403 	__s32	res;		/* result code for this event */
404 	__u32	flags;
405 
406 	/*
407 	 * If the ring is initialized with IORING_SETUP_CQE32, then this field
408 	 * contains 16-bytes of padding, doubling the size of the CQE.
409 	 */
410 	__u64 big_cqe[];
411 };
412 
413 /*
414  * cqe->flags
415  *
416  * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID
417  * IORING_CQE_F_MORE	If set, parent SQE will generate more CQE entries
418  * IORING_CQE_F_SOCK_NONEMPTY	If set, more data to read after socket recv
419  * IORING_CQE_F_NOTIF	Set for notification CQEs. Can be used to distinct
420  * 			them from sends.
421  */
422 #define IORING_CQE_F_BUFFER		(1U << 0)
423 #define IORING_CQE_F_MORE		(1U << 1)
424 #define IORING_CQE_F_SOCK_NONEMPTY	(1U << 2)
425 #define IORING_CQE_F_NOTIF		(1U << 3)
426 
427 enum {
428 	IORING_CQE_BUFFER_SHIFT		= 16,
429 };
430 
431 /*
432  * Magic offsets for the application to mmap the data it needs
433  */
434 #define IORING_OFF_SQ_RING		0ULL
435 #define IORING_OFF_CQ_RING		0x8000000ULL
436 #define IORING_OFF_SQES			0x10000000ULL
437 #define IORING_OFF_PBUF_RING		0x80000000ULL
438 #define IORING_OFF_PBUF_SHIFT		16
439 #define IORING_OFF_MMAP_MASK		0xf8000000ULL
440 
441 /*
442  * Filled with the offset for mmap(2)
443  */
444 struct io_sqring_offsets {
445 	__u32 head;
446 	__u32 tail;
447 	__u32 ring_mask;
448 	__u32 ring_entries;
449 	__u32 flags;
450 	__u32 dropped;
451 	__u32 array;
452 	__u32 resv1;
453 	__u64 user_addr;
454 };
455 
456 /*
457  * sq_ring->flags
458  */
459 #define IORING_SQ_NEED_WAKEUP	(1U << 0) /* needs io_uring_enter wakeup */
460 #define IORING_SQ_CQ_OVERFLOW	(1U << 1) /* CQ ring is overflown */
461 #define IORING_SQ_TASKRUN	(1U << 2) /* task should enter the kernel */
462 
463 struct io_cqring_offsets {
464 	__u32 head;
465 	__u32 tail;
466 	__u32 ring_mask;
467 	__u32 ring_entries;
468 	__u32 overflow;
469 	__u32 cqes;
470 	__u32 flags;
471 	__u32 resv1;
472 	__u64 user_addr;
473 };
474 
475 /*
476  * cq_ring->flags
477  */
478 
479 /* disable eventfd notifications */
480 #define IORING_CQ_EVENTFD_DISABLED	(1U << 0)
481 
482 /*
483  * io_uring_enter(2) flags
484  */
485 #define IORING_ENTER_GETEVENTS		(1U << 0)
486 #define IORING_ENTER_SQ_WAKEUP		(1U << 1)
487 #define IORING_ENTER_SQ_WAIT		(1U << 2)
488 #define IORING_ENTER_EXT_ARG		(1U << 3)
489 #define IORING_ENTER_REGISTERED_RING	(1U << 4)
490 
491 /*
492  * Passed in for io_uring_setup(2). Copied back with updated info on success
493  */
494 struct io_uring_params {
495 	__u32 sq_entries;
496 	__u32 cq_entries;
497 	__u32 flags;
498 	__u32 sq_thread_cpu;
499 	__u32 sq_thread_idle;
500 	__u32 features;
501 	__u32 wq_fd;
502 	__u32 resv[3];
503 	struct io_sqring_offsets sq_off;
504 	struct io_cqring_offsets cq_off;
505 };
506 
507 /*
508  * io_uring_params->features flags
509  */
510 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
511 #define IORING_FEAT_NODROP		(1U << 1)
512 #define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
513 #define IORING_FEAT_RW_CUR_POS		(1U << 3)
514 #define IORING_FEAT_CUR_PERSONALITY	(1U << 4)
515 #define IORING_FEAT_FAST_POLL		(1U << 5)
516 #define IORING_FEAT_POLL_32BITS 	(1U << 6)
517 #define IORING_FEAT_SQPOLL_NONFIXED	(1U << 7)
518 #define IORING_FEAT_EXT_ARG		(1U << 8)
519 #define IORING_FEAT_NATIVE_WORKERS	(1U << 9)
520 #define IORING_FEAT_RSRC_TAGS		(1U << 10)
521 #define IORING_FEAT_CQE_SKIP		(1U << 11)
522 #define IORING_FEAT_LINKED_FILE		(1U << 12)
523 #define IORING_FEAT_REG_REG_RING	(1U << 13)
524 
525 /*
526  * io_uring_register(2) opcodes and arguments
527  */
528 enum {
529 	IORING_REGISTER_BUFFERS			= 0,
530 	IORING_UNREGISTER_BUFFERS		= 1,
531 	IORING_REGISTER_FILES			= 2,
532 	IORING_UNREGISTER_FILES			= 3,
533 	IORING_REGISTER_EVENTFD			= 4,
534 	IORING_UNREGISTER_EVENTFD		= 5,
535 	IORING_REGISTER_FILES_UPDATE		= 6,
536 	IORING_REGISTER_EVENTFD_ASYNC		= 7,
537 	IORING_REGISTER_PROBE			= 8,
538 	IORING_REGISTER_PERSONALITY		= 9,
539 	IORING_UNREGISTER_PERSONALITY		= 10,
540 	IORING_REGISTER_RESTRICTIONS		= 11,
541 	IORING_REGISTER_ENABLE_RINGS		= 12,
542 
543 	/* extended with tagging */
544 	IORING_REGISTER_FILES2			= 13,
545 	IORING_REGISTER_FILES_UPDATE2		= 14,
546 	IORING_REGISTER_BUFFERS2		= 15,
547 	IORING_REGISTER_BUFFERS_UPDATE		= 16,
548 
549 	/* set/clear io-wq thread affinities */
550 	IORING_REGISTER_IOWQ_AFF		= 17,
551 	IORING_UNREGISTER_IOWQ_AFF		= 18,
552 
553 	/* set/get max number of io-wq workers */
554 	IORING_REGISTER_IOWQ_MAX_WORKERS	= 19,
555 
556 	/* register/unregister io_uring fd with the ring */
557 	IORING_REGISTER_RING_FDS		= 20,
558 	IORING_UNREGISTER_RING_FDS		= 21,
559 
560 	/* register ring based provide buffer group */
561 	IORING_REGISTER_PBUF_RING		= 22,
562 	IORING_UNREGISTER_PBUF_RING		= 23,
563 
564 	/* sync cancelation API */
565 	IORING_REGISTER_SYNC_CANCEL		= 24,
566 
567 	/* register a range of fixed file slots for automatic slot allocation */
568 	IORING_REGISTER_FILE_ALLOC_RANGE	= 25,
569 
570 	/* return status information for a buffer group */
571 	IORING_REGISTER_PBUF_STATUS		= 26,
572 
573 	/* this goes last */
574 	IORING_REGISTER_LAST,
575 
576 	/* flag added to the opcode to use a registered ring fd */
577 	IORING_REGISTER_USE_REGISTERED_RING	= 1U << 31
578 };
579 
580 /* io-wq worker categories */
581 enum {
582 	IO_WQ_BOUND,
583 	IO_WQ_UNBOUND,
584 };
585 
586 /* deprecated, see struct io_uring_rsrc_update */
587 struct io_uring_files_update {
588 	__u32 offset;
589 	__u32 resv;
590 	__aligned_u64 /* __s32 * */ fds;
591 };
592 
593 /*
594  * Register a fully sparse file space, rather than pass in an array of all
595  * -1 file descriptors.
596  */
597 #define IORING_RSRC_REGISTER_SPARSE	(1U << 0)
598 
599 struct io_uring_rsrc_register {
600 	__u32 nr;
601 	__u32 flags;
602 	__u64 resv2;
603 	__aligned_u64 data;
604 	__aligned_u64 tags;
605 };
606 
607 struct io_uring_rsrc_update {
608 	__u32 offset;
609 	__u32 resv;
610 	__aligned_u64 data;
611 };
612 
613 struct io_uring_rsrc_update2 {
614 	__u32 offset;
615 	__u32 resv;
616 	__aligned_u64 data;
617 	__aligned_u64 tags;
618 	__u32 nr;
619 	__u32 resv2;
620 };
621 
622 /* Skip updating fd indexes set to this value in the fd table */
623 #define IORING_REGISTER_FILES_SKIP	(-2)
624 
625 #define IO_URING_OP_SUPPORTED	(1U << 0)
626 
627 struct io_uring_probe_op {
628 	__u8 op;
629 	__u8 resv;
630 	__u16 flags;	/* IO_URING_OP_* flags */
631 	__u32 resv2;
632 };
633 
634 struct io_uring_probe {
635 	__u8 last_op;	/* last opcode supported */
636 	__u8 ops_len;	/* length of ops[] array below */
637 	__u16 resv;
638 	__u32 resv2[3];
639 	struct io_uring_probe_op ops[];
640 };
641 
642 struct io_uring_restriction {
643 	__u16 opcode;
644 	union {
645 		__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
646 		__u8 sqe_op;      /* IORING_RESTRICTION_SQE_OP */
647 		__u8 sqe_flags;   /* IORING_RESTRICTION_SQE_FLAGS_* */
648 	};
649 	__u8 resv;
650 	__u32 resv2[3];
651 };
652 
653 struct io_uring_buf {
654 	__u64	addr;
655 	__u32	len;
656 	__u16	bid;
657 	__u16	resv;
658 };
659 
660 struct io_uring_buf_ring {
661 	union {
662 		/*
663 		 * To avoid spilling into more pages than we need to, the
664 		 * ring tail is overlaid with the io_uring_buf->resv field.
665 		 */
666 		struct {
667 			__u64	resv1;
668 			__u32	resv2;
669 			__u16	resv3;
670 			__u16	tail;
671 		};
672 		__DECLARE_FLEX_ARRAY(struct io_uring_buf, bufs);
673 	};
674 };
675 
676 /*
677  * Flags for IORING_REGISTER_PBUF_RING.
678  *
679  * IOU_PBUF_RING_MMAP:	If set, kernel will allocate the memory for the ring.
680  *			The application must not set a ring_addr in struct
681  *			io_uring_buf_reg, instead it must subsequently call
682  *			mmap(2) with the offset set as:
683  *			IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)
684  *			to get a virtual mapping for the ring.
685  */
686 enum {
687 	IOU_PBUF_RING_MMAP	= 1,
688 };
689 
690 /* argument for IORING_(UN)REGISTER_PBUF_RING */
691 struct io_uring_buf_reg {
692 	__u64	ring_addr;
693 	__u32	ring_entries;
694 	__u16	bgid;
695 	__u16	flags;
696 	__u64	resv[3];
697 };
698 
699 /* argument for IORING_REGISTER_PBUF_STATUS */
700 struct io_uring_buf_status {
701 	__u32	buf_group;	/* input */
702 	__u32	head;		/* output */
703 	__u32	resv[8];
704 };
705 
706 /*
707  * io_uring_restriction->opcode values
708  */
709 enum {
710 	/* Allow an io_uring_register(2) opcode */
711 	IORING_RESTRICTION_REGISTER_OP		= 0,
712 
713 	/* Allow an sqe opcode */
714 	IORING_RESTRICTION_SQE_OP		= 1,
715 
716 	/* Allow sqe flags */
717 	IORING_RESTRICTION_SQE_FLAGS_ALLOWED	= 2,
718 
719 	/* Require sqe flags (these flags must be set on each submission) */
720 	IORING_RESTRICTION_SQE_FLAGS_REQUIRED	= 3,
721 
722 	IORING_RESTRICTION_LAST
723 };
724 
725 struct io_uring_getevents_arg {
726 	__u64	sigmask;
727 	__u32	sigmask_sz;
728 	__u32	pad;
729 	__u64	ts;
730 };
731 
732 /*
733  * Argument for IORING_REGISTER_SYNC_CANCEL
734  */
735 struct io_uring_sync_cancel_reg {
736 	__u64				addr;
737 	__s32				fd;
738 	__u32				flags;
739 	struct __kernel_timespec	timeout;
740 	__u8				opcode;
741 	__u8				pad[7];
742 	__u64				pad2[3];
743 };
744 
745 /*
746  * Argument for IORING_REGISTER_FILE_ALLOC_RANGE
747  * The range is specified as [off, off + len)
748  */
749 struct io_uring_file_index_range {
750 	__u32	off;
751 	__u32	len;
752 	__u64	resv;
753 };
754 
755 struct io_uring_recvmsg_out {
756 	__u32 namelen;
757 	__u32 controllen;
758 	__u32 payloadlen;
759 	__u32 flags;
760 };
761 
762 /*
763  * Argument for IORING_OP_URING_CMD when file is a socket
764  */
765 enum {
766 	SOCKET_URING_OP_SIOCINQ		= 0,
767 	SOCKET_URING_OP_SIOCOUTQ,
768 	SOCKET_URING_OP_GETSOCKOPT,
769 	SOCKET_URING_OP_SETSOCKOPT,
770 };
771 
772 #ifdef __cplusplus
773 }
774 #endif
775 
776 #endif
777