xref: /openbmc/linux/include/uapi/linux/io_uring.h (revision c57f3dbc3bd9ae3c4cf72c9937de205458815c8d)
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 		__u32		hardlink_flags;
48 	};
49 	__u64	user_data;	/* data to be passed back at completion time */
50 	/* pack this to avoid bogus arm OABI complaints */
51 	union {
52 		/* index into fixed buffers, if used */
53 		__u16	buf_index;
54 		/* for grouped buffer selection */
55 		__u16	buf_group;
56 	} __attribute__((packed));
57 	/* personality to use, if used */
58 	__u16	personality;
59 	union {
60 		__s32	splice_fd_in;
61 		__u32	file_index;
62 	};
63 	__u64	__pad2[2];
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 	IOSQE_CQE_SKIP_SUCCESS_BIT,
74 };
75 
76 /*
77  * sqe->flags
78  */
79 /* use fixed fileset */
80 #define IOSQE_FIXED_FILE	(1U << IOSQE_FIXED_FILE_BIT)
81 /* issue after inflight IO */
82 #define IOSQE_IO_DRAIN		(1U << IOSQE_IO_DRAIN_BIT)
83 /* links next sqe */
84 #define IOSQE_IO_LINK		(1U << IOSQE_IO_LINK_BIT)
85 /* like LINK, but stronger */
86 #define IOSQE_IO_HARDLINK	(1U << IOSQE_IO_HARDLINK_BIT)
87 /* always go async */
88 #define IOSQE_ASYNC		(1U << IOSQE_ASYNC_BIT)
89 /* select buffer from sqe->buf_group */
90 #define IOSQE_BUFFER_SELECT	(1U << IOSQE_BUFFER_SELECT_BIT)
91 /* don't post CQE if request succeeded */
92 #define IOSQE_CQE_SKIP_SUCCESS	(1U << IOSQE_CQE_SKIP_SUCCESS_BIT)
93 
94 /*
95  * io_uring_setup() flags
96  */
97 #define IORING_SETUP_IOPOLL	(1U << 0)	/* io_context is polled */
98 #define IORING_SETUP_SQPOLL	(1U << 1)	/* SQ poll thread */
99 #define IORING_SETUP_SQ_AFF	(1U << 2)	/* sq_thread_cpu is valid */
100 #define IORING_SETUP_CQSIZE	(1U << 3)	/* app defines CQ size */
101 #define IORING_SETUP_CLAMP	(1U << 4)	/* clamp SQ/CQ ring sizes */
102 #define IORING_SETUP_ATTACH_WQ	(1U << 5)	/* attach to existing wq */
103 #define IORING_SETUP_R_DISABLED	(1U << 6)	/* start with ring disabled */
104 #define IORING_SETUP_SUBMIT_ALL	(1U << 7)	/* continue submit on error */
105 
106 enum {
107 	IORING_OP_NOP,
108 	IORING_OP_READV,
109 	IORING_OP_WRITEV,
110 	IORING_OP_FSYNC,
111 	IORING_OP_READ_FIXED,
112 	IORING_OP_WRITE_FIXED,
113 	IORING_OP_POLL_ADD,
114 	IORING_OP_POLL_REMOVE,
115 	IORING_OP_SYNC_FILE_RANGE,
116 	IORING_OP_SENDMSG,
117 	IORING_OP_RECVMSG,
118 	IORING_OP_TIMEOUT,
119 	IORING_OP_TIMEOUT_REMOVE,
120 	IORING_OP_ACCEPT,
121 	IORING_OP_ASYNC_CANCEL,
122 	IORING_OP_LINK_TIMEOUT,
123 	IORING_OP_CONNECT,
124 	IORING_OP_FALLOCATE,
125 	IORING_OP_OPENAT,
126 	IORING_OP_CLOSE,
127 	IORING_OP_FILES_UPDATE,
128 	IORING_OP_STATX,
129 	IORING_OP_READ,
130 	IORING_OP_WRITE,
131 	IORING_OP_FADVISE,
132 	IORING_OP_MADVISE,
133 	IORING_OP_SEND,
134 	IORING_OP_RECV,
135 	IORING_OP_OPENAT2,
136 	IORING_OP_EPOLL_CTL,
137 	IORING_OP_SPLICE,
138 	IORING_OP_PROVIDE_BUFFERS,
139 	IORING_OP_REMOVE_BUFFERS,
140 	IORING_OP_TEE,
141 	IORING_OP_SHUTDOWN,
142 	IORING_OP_RENAMEAT,
143 	IORING_OP_UNLINKAT,
144 	IORING_OP_MKDIRAT,
145 	IORING_OP_SYMLINKAT,
146 	IORING_OP_LINKAT,
147 	IORING_OP_MSG_RING,
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 #define IORING_TIMEOUT_BOOTTIME		(1U << 2)
164 #define IORING_TIMEOUT_REALTIME		(1U << 3)
165 #define IORING_LINK_TIMEOUT_UPDATE	(1U << 4)
166 #define IORING_TIMEOUT_ETIME_SUCCESS	(1U << 5)
167 #define IORING_TIMEOUT_CLOCK_MASK	(IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
168 #define IORING_TIMEOUT_UPDATE_MASK	(IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
169 /*
170  * sqe->splice_flags
171  * extends splice(2) flags
172  */
173 #define SPLICE_F_FD_IN_FIXED	(1U << 31) /* the last bit of __u32 */
174 
175 /*
176  * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
177  * command flags for POLL_ADD are stored in sqe->len.
178  *
179  * IORING_POLL_ADD_MULTI	Multishot poll. Sets IORING_CQE_F_MORE if
180  *				the poll handler will continue to report
181  *				CQEs on behalf of the same SQE.
182  *
183  * IORING_POLL_UPDATE		Update existing poll request, matching
184  *				sqe->addr as the old user_data field.
185  */
186 #define IORING_POLL_ADD_MULTI	(1U << 0)
187 #define IORING_POLL_UPDATE_EVENTS	(1U << 1)
188 #define IORING_POLL_UPDATE_USER_DATA	(1U << 2)
189 
190 /*
191  * IO completion data structure (Completion Queue Entry)
192  */
193 struct io_uring_cqe {
194 	__u64	user_data;	/* sqe->data submission passed back */
195 	__s32	res;		/* result code for this event */
196 	__u32	flags;
197 };
198 
199 /*
200  * cqe->flags
201  *
202  * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID
203  * IORING_CQE_F_MORE	If set, parent SQE will generate more CQE entries
204  */
205 #define IORING_CQE_F_BUFFER		(1U << 0)
206 #define IORING_CQE_F_MORE		(1U << 1)
207 
208 enum {
209 	IORING_CQE_BUFFER_SHIFT		= 16,
210 };
211 
212 /*
213  * Magic offsets for the application to mmap the data it needs
214  */
215 #define IORING_OFF_SQ_RING		0ULL
216 #define IORING_OFF_CQ_RING		0x8000000ULL
217 #define IORING_OFF_SQES			0x10000000ULL
218 
219 /*
220  * Filled with the offset for mmap(2)
221  */
222 struct io_sqring_offsets {
223 	__u32 head;
224 	__u32 tail;
225 	__u32 ring_mask;
226 	__u32 ring_entries;
227 	__u32 flags;
228 	__u32 dropped;
229 	__u32 array;
230 	__u32 resv1;
231 	__u64 resv2;
232 };
233 
234 /*
235  * sq_ring->flags
236  */
237 #define IORING_SQ_NEED_WAKEUP	(1U << 0) /* needs io_uring_enter wakeup */
238 #define IORING_SQ_CQ_OVERFLOW	(1U << 1) /* CQ ring is overflown */
239 
240 struct io_cqring_offsets {
241 	__u32 head;
242 	__u32 tail;
243 	__u32 ring_mask;
244 	__u32 ring_entries;
245 	__u32 overflow;
246 	__u32 cqes;
247 	__u32 flags;
248 	__u32 resv1;
249 	__u64 resv2;
250 };
251 
252 /*
253  * cq_ring->flags
254  */
255 
256 /* disable eventfd notifications */
257 #define IORING_CQ_EVENTFD_DISABLED	(1U << 0)
258 
259 /*
260  * io_uring_enter(2) flags
261  */
262 #define IORING_ENTER_GETEVENTS		(1U << 0)
263 #define IORING_ENTER_SQ_WAKEUP		(1U << 1)
264 #define IORING_ENTER_SQ_WAIT		(1U << 2)
265 #define IORING_ENTER_EXT_ARG		(1U << 3)
266 #define IORING_ENTER_REGISTERED_RING	(1U << 4)
267 
268 /*
269  * Passed in for io_uring_setup(2). Copied back with updated info on success
270  */
271 struct io_uring_params {
272 	__u32 sq_entries;
273 	__u32 cq_entries;
274 	__u32 flags;
275 	__u32 sq_thread_cpu;
276 	__u32 sq_thread_idle;
277 	__u32 features;
278 	__u32 wq_fd;
279 	__u32 resv[3];
280 	struct io_sqring_offsets sq_off;
281 	struct io_cqring_offsets cq_off;
282 };
283 
284 /*
285  * io_uring_params->features flags
286  */
287 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
288 #define IORING_FEAT_NODROP		(1U << 1)
289 #define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
290 #define IORING_FEAT_RW_CUR_POS		(1U << 3)
291 #define IORING_FEAT_CUR_PERSONALITY	(1U << 4)
292 #define IORING_FEAT_FAST_POLL		(1U << 5)
293 #define IORING_FEAT_POLL_32BITS 	(1U << 6)
294 #define IORING_FEAT_SQPOLL_NONFIXED	(1U << 7)
295 #define IORING_FEAT_EXT_ARG		(1U << 8)
296 #define IORING_FEAT_NATIVE_WORKERS	(1U << 9)
297 #define IORING_FEAT_RSRC_TAGS		(1U << 10)
298 #define IORING_FEAT_CQE_SKIP		(1U << 11)
299 
300 /*
301  * io_uring_register(2) opcodes and arguments
302  */
303 enum {
304 	IORING_REGISTER_BUFFERS			= 0,
305 	IORING_UNREGISTER_BUFFERS		= 1,
306 	IORING_REGISTER_FILES			= 2,
307 	IORING_UNREGISTER_FILES			= 3,
308 	IORING_REGISTER_EVENTFD			= 4,
309 	IORING_UNREGISTER_EVENTFD		= 5,
310 	IORING_REGISTER_FILES_UPDATE		= 6,
311 	IORING_REGISTER_EVENTFD_ASYNC		= 7,
312 	IORING_REGISTER_PROBE			= 8,
313 	IORING_REGISTER_PERSONALITY		= 9,
314 	IORING_UNREGISTER_PERSONALITY		= 10,
315 	IORING_REGISTER_RESTRICTIONS		= 11,
316 	IORING_REGISTER_ENABLE_RINGS		= 12,
317 
318 	/* extended with tagging */
319 	IORING_REGISTER_FILES2			= 13,
320 	IORING_REGISTER_FILES_UPDATE2		= 14,
321 	IORING_REGISTER_BUFFERS2		= 15,
322 	IORING_REGISTER_BUFFERS_UPDATE		= 16,
323 
324 	/* set/clear io-wq thread affinities */
325 	IORING_REGISTER_IOWQ_AFF		= 17,
326 	IORING_UNREGISTER_IOWQ_AFF		= 18,
327 
328 	/* set/get max number of io-wq workers */
329 	IORING_REGISTER_IOWQ_MAX_WORKERS	= 19,
330 
331 	/* register/unregister io_uring fd with the ring */
332 	IORING_REGISTER_RING_FDS		= 20,
333 	IORING_UNREGISTER_RING_FDS		= 21,
334 
335 	/* this goes last */
336 	IORING_REGISTER_LAST
337 };
338 
339 /* io-wq worker categories */
340 enum {
341 	IO_WQ_BOUND,
342 	IO_WQ_UNBOUND,
343 };
344 
345 /* deprecated, see struct io_uring_rsrc_update */
346 struct io_uring_files_update {
347 	__u32 offset;
348 	__u32 resv;
349 	__aligned_u64 /* __s32 * */ fds;
350 };
351 
352 struct io_uring_rsrc_register {
353 	__u32 nr;
354 	__u32 resv;
355 	__u64 resv2;
356 	__aligned_u64 data;
357 	__aligned_u64 tags;
358 };
359 
360 struct io_uring_rsrc_update {
361 	__u32 offset;
362 	__u32 resv;
363 	__aligned_u64 data;
364 };
365 
366 struct io_uring_rsrc_update2 {
367 	__u32 offset;
368 	__u32 resv;
369 	__aligned_u64 data;
370 	__aligned_u64 tags;
371 	__u32 nr;
372 	__u32 resv2;
373 };
374 
375 /* Skip updating fd indexes set to this value in the fd table */
376 #define IORING_REGISTER_FILES_SKIP	(-2)
377 
378 #define IO_URING_OP_SUPPORTED	(1U << 0)
379 
380 struct io_uring_probe_op {
381 	__u8 op;
382 	__u8 resv;
383 	__u16 flags;	/* IO_URING_OP_* flags */
384 	__u32 resv2;
385 };
386 
387 struct io_uring_probe {
388 	__u8 last_op;	/* last opcode supported */
389 	__u8 ops_len;	/* length of ops[] array below */
390 	__u16 resv;
391 	__u32 resv2[3];
392 	struct io_uring_probe_op ops[0];
393 };
394 
395 struct io_uring_restriction {
396 	__u16 opcode;
397 	union {
398 		__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
399 		__u8 sqe_op;      /* IORING_RESTRICTION_SQE_OP */
400 		__u8 sqe_flags;   /* IORING_RESTRICTION_SQE_FLAGS_* */
401 	};
402 	__u8 resv;
403 	__u32 resv2[3];
404 };
405 
406 /*
407  * io_uring_restriction->opcode values
408  */
409 enum {
410 	/* Allow an io_uring_register(2) opcode */
411 	IORING_RESTRICTION_REGISTER_OP		= 0,
412 
413 	/* Allow an sqe opcode */
414 	IORING_RESTRICTION_SQE_OP		= 1,
415 
416 	/* Allow sqe flags */
417 	IORING_RESTRICTION_SQE_FLAGS_ALLOWED	= 2,
418 
419 	/* Require sqe flags (these flags must be set on each submission) */
420 	IORING_RESTRICTION_SQE_FLAGS_REQUIRED	= 3,
421 
422 	IORING_RESTRICTION_LAST
423 };
424 
425 struct io_uring_getevents_arg {
426 	__u64	sigmask;
427 	__u32	sigmask_sz;
428 	__u32	pad;
429 	__u64	ts;
430 };
431 
432 #endif
433