xref: /openbmc/linux/include/uapi/linux/io_uring.h (revision 496cc140279b4517a23f4534e468ec9c66283f4b)
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 
105 enum {
106 	IORING_OP_NOP,
107 	IORING_OP_READV,
108 	IORING_OP_WRITEV,
109 	IORING_OP_FSYNC,
110 	IORING_OP_READ_FIXED,
111 	IORING_OP_WRITE_FIXED,
112 	IORING_OP_POLL_ADD,
113 	IORING_OP_POLL_REMOVE,
114 	IORING_OP_SYNC_FILE_RANGE,
115 	IORING_OP_SENDMSG,
116 	IORING_OP_RECVMSG,
117 	IORING_OP_TIMEOUT,
118 	IORING_OP_TIMEOUT_REMOVE,
119 	IORING_OP_ACCEPT,
120 	IORING_OP_ASYNC_CANCEL,
121 	IORING_OP_LINK_TIMEOUT,
122 	IORING_OP_CONNECT,
123 	IORING_OP_FALLOCATE,
124 	IORING_OP_OPENAT,
125 	IORING_OP_CLOSE,
126 	IORING_OP_FILES_UPDATE,
127 	IORING_OP_STATX,
128 	IORING_OP_READ,
129 	IORING_OP_WRITE,
130 	IORING_OP_FADVISE,
131 	IORING_OP_MADVISE,
132 	IORING_OP_SEND,
133 	IORING_OP_RECV,
134 	IORING_OP_OPENAT2,
135 	IORING_OP_EPOLL_CTL,
136 	IORING_OP_SPLICE,
137 	IORING_OP_PROVIDE_BUFFERS,
138 	IORING_OP_REMOVE_BUFFERS,
139 	IORING_OP_TEE,
140 	IORING_OP_SHUTDOWN,
141 	IORING_OP_RENAMEAT,
142 	IORING_OP_UNLINKAT,
143 	IORING_OP_MKDIRAT,
144 	IORING_OP_SYMLINKAT,
145 	IORING_OP_LINKAT,
146 
147 	/* this goes last, obviously */
148 	IORING_OP_LAST,
149 };
150 
151 /*
152  * sqe->fsync_flags
153  */
154 #define IORING_FSYNC_DATASYNC	(1U << 0)
155 
156 /*
157  * sqe->timeout_flags
158  */
159 #define IORING_TIMEOUT_ABS		(1U << 0)
160 #define IORING_TIMEOUT_UPDATE		(1U << 1)
161 #define IORING_TIMEOUT_BOOTTIME		(1U << 2)
162 #define IORING_TIMEOUT_REALTIME		(1U << 3)
163 #define IORING_LINK_TIMEOUT_UPDATE	(1U << 4)
164 #define IORING_TIMEOUT_ETIME_SUCCESS	(1U << 5)
165 #define IORING_TIMEOUT_CLOCK_MASK	(IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
166 #define IORING_TIMEOUT_UPDATE_MASK	(IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
167 /*
168  * sqe->splice_flags
169  * extends splice(2) flags
170  */
171 #define SPLICE_F_FD_IN_FIXED	(1U << 31) /* the last bit of __u32 */
172 
173 /*
174  * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
175  * command flags for POLL_ADD are stored in sqe->len.
176  *
177  * IORING_POLL_ADD_MULTI	Multishot poll. Sets IORING_CQE_F_MORE if
178  *				the poll handler will continue to report
179  *				CQEs on behalf of the same SQE.
180  *
181  * IORING_POLL_UPDATE		Update existing poll request, matching
182  *				sqe->addr as the old user_data field.
183  */
184 #define IORING_POLL_ADD_MULTI	(1U << 0)
185 #define IORING_POLL_UPDATE_EVENTS	(1U << 1)
186 #define IORING_POLL_UPDATE_USER_DATA	(1U << 2)
187 
188 /*
189  * IO completion data structure (Completion Queue Entry)
190  */
191 struct io_uring_cqe {
192 	__u64	user_data;	/* sqe->data submission passed back */
193 	__s32	res;		/* result code for this event */
194 	__u32	flags;
195 };
196 
197 /*
198  * cqe->flags
199  *
200  * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID
201  * IORING_CQE_F_MORE	If set, parent SQE will generate more CQE entries
202  */
203 #define IORING_CQE_F_BUFFER		(1U << 0)
204 #define IORING_CQE_F_MORE		(1U << 1)
205 
206 enum {
207 	IORING_CQE_BUFFER_SHIFT		= 16,
208 };
209 
210 /*
211  * Magic offsets for the application to mmap the data it needs
212  */
213 #define IORING_OFF_SQ_RING		0ULL
214 #define IORING_OFF_CQ_RING		0x8000000ULL
215 #define IORING_OFF_SQES			0x10000000ULL
216 
217 /*
218  * Filled with the offset for mmap(2)
219  */
220 struct io_sqring_offsets {
221 	__u32 head;
222 	__u32 tail;
223 	__u32 ring_mask;
224 	__u32 ring_entries;
225 	__u32 flags;
226 	__u32 dropped;
227 	__u32 array;
228 	__u32 resv1;
229 	__u64 resv2;
230 };
231 
232 /*
233  * sq_ring->flags
234  */
235 #define IORING_SQ_NEED_WAKEUP	(1U << 0) /* needs io_uring_enter wakeup */
236 #define IORING_SQ_CQ_OVERFLOW	(1U << 1) /* CQ ring is overflown */
237 
238 struct io_cqring_offsets {
239 	__u32 head;
240 	__u32 tail;
241 	__u32 ring_mask;
242 	__u32 ring_entries;
243 	__u32 overflow;
244 	__u32 cqes;
245 	__u32 flags;
246 	__u32 resv1;
247 	__u64 resv2;
248 };
249 
250 /*
251  * cq_ring->flags
252  */
253 
254 /* disable eventfd notifications */
255 #define IORING_CQ_EVENTFD_DISABLED	(1U << 0)
256 
257 /*
258  * io_uring_enter(2) flags
259  */
260 #define IORING_ENTER_GETEVENTS	(1U << 0)
261 #define IORING_ENTER_SQ_WAKEUP	(1U << 1)
262 #define IORING_ENTER_SQ_WAIT	(1U << 2)
263 #define IORING_ENTER_EXT_ARG	(1U << 3)
264 
265 /*
266  * Passed in for io_uring_setup(2). Copied back with updated info on success
267  */
268 struct io_uring_params {
269 	__u32 sq_entries;
270 	__u32 cq_entries;
271 	__u32 flags;
272 	__u32 sq_thread_cpu;
273 	__u32 sq_thread_idle;
274 	__u32 features;
275 	__u32 wq_fd;
276 	__u32 resv[3];
277 	struct io_sqring_offsets sq_off;
278 	struct io_cqring_offsets cq_off;
279 };
280 
281 /*
282  * io_uring_params->features flags
283  */
284 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
285 #define IORING_FEAT_NODROP		(1U << 1)
286 #define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
287 #define IORING_FEAT_RW_CUR_POS		(1U << 3)
288 #define IORING_FEAT_CUR_PERSONALITY	(1U << 4)
289 #define IORING_FEAT_FAST_POLL		(1U << 5)
290 #define IORING_FEAT_POLL_32BITS 	(1U << 6)
291 #define IORING_FEAT_SQPOLL_NONFIXED	(1U << 7)
292 #define IORING_FEAT_EXT_ARG		(1U << 8)
293 #define IORING_FEAT_NATIVE_WORKERS	(1U << 9)
294 #define IORING_FEAT_RSRC_TAGS		(1U << 10)
295 #define IORING_FEAT_CQE_SKIP		(1U << 11)
296 
297 /*
298  * io_uring_register(2) opcodes and arguments
299  */
300 enum {
301 	IORING_REGISTER_BUFFERS			= 0,
302 	IORING_UNREGISTER_BUFFERS		= 1,
303 	IORING_REGISTER_FILES			= 2,
304 	IORING_UNREGISTER_FILES			= 3,
305 	IORING_REGISTER_EVENTFD			= 4,
306 	IORING_UNREGISTER_EVENTFD		= 5,
307 	IORING_REGISTER_FILES_UPDATE		= 6,
308 	IORING_REGISTER_EVENTFD_ASYNC		= 7,
309 	IORING_REGISTER_PROBE			= 8,
310 	IORING_REGISTER_PERSONALITY		= 9,
311 	IORING_UNREGISTER_PERSONALITY		= 10,
312 	IORING_REGISTER_RESTRICTIONS		= 11,
313 	IORING_REGISTER_ENABLE_RINGS		= 12,
314 
315 	/* extended with tagging */
316 	IORING_REGISTER_FILES2			= 13,
317 	IORING_REGISTER_FILES_UPDATE2		= 14,
318 	IORING_REGISTER_BUFFERS2		= 15,
319 	IORING_REGISTER_BUFFERS_UPDATE		= 16,
320 
321 	/* set/clear io-wq thread affinities */
322 	IORING_REGISTER_IOWQ_AFF		= 17,
323 	IORING_UNREGISTER_IOWQ_AFF		= 18,
324 
325 	/* set/get max number of io-wq workers */
326 	IORING_REGISTER_IOWQ_MAX_WORKERS	= 19,
327 
328 	/* this goes last */
329 	IORING_REGISTER_LAST
330 };
331 
332 /* io-wq worker categories */
333 enum {
334 	IO_WQ_BOUND,
335 	IO_WQ_UNBOUND,
336 };
337 
338 /* deprecated, see struct io_uring_rsrc_update */
339 struct io_uring_files_update {
340 	__u32 offset;
341 	__u32 resv;
342 	__aligned_u64 /* __s32 * */ fds;
343 };
344 
345 struct io_uring_rsrc_register {
346 	__u32 nr;
347 	__u32 resv;
348 	__u64 resv2;
349 	__aligned_u64 data;
350 	__aligned_u64 tags;
351 };
352 
353 struct io_uring_rsrc_update {
354 	__u32 offset;
355 	__u32 resv;
356 	__aligned_u64 data;
357 };
358 
359 struct io_uring_rsrc_update2 {
360 	__u32 offset;
361 	__u32 resv;
362 	__aligned_u64 data;
363 	__aligned_u64 tags;
364 	__u32 nr;
365 	__u32 resv2;
366 };
367 
368 /* Skip updating fd indexes set to this value in the fd table */
369 #define IORING_REGISTER_FILES_SKIP	(-2)
370 
371 #define IO_URING_OP_SUPPORTED	(1U << 0)
372 
373 struct io_uring_probe_op {
374 	__u8 op;
375 	__u8 resv;
376 	__u16 flags;	/* IO_URING_OP_* flags */
377 	__u32 resv2;
378 };
379 
380 struct io_uring_probe {
381 	__u8 last_op;	/* last opcode supported */
382 	__u8 ops_len;	/* length of ops[] array below */
383 	__u16 resv;
384 	__u32 resv2[3];
385 	struct io_uring_probe_op ops[0];
386 };
387 
388 struct io_uring_restriction {
389 	__u16 opcode;
390 	union {
391 		__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
392 		__u8 sqe_op;      /* IORING_RESTRICTION_SQE_OP */
393 		__u8 sqe_flags;   /* IORING_RESTRICTION_SQE_FLAGS_* */
394 	};
395 	__u8 resv;
396 	__u32 resv2[3];
397 };
398 
399 /*
400  * io_uring_restriction->opcode values
401  */
402 enum {
403 	/* Allow an io_uring_register(2) opcode */
404 	IORING_RESTRICTION_REGISTER_OP		= 0,
405 
406 	/* Allow an sqe opcode */
407 	IORING_RESTRICTION_SQE_OP		= 1,
408 
409 	/* Allow sqe flags */
410 	IORING_RESTRICTION_SQE_FLAGS_ALLOWED	= 2,
411 
412 	/* Require sqe flags (these flags must be set on each submission) */
413 	IORING_RESTRICTION_SQE_FLAGS_REQUIRED	= 3,
414 
415 	IORING_RESTRICTION_LAST
416 };
417 
418 struct io_uring_getevents_arg {
419 	__u64	sigmask;
420 	__u32	sigmask_sz;
421 	__u32	pad;
422 	__u64	ts;
423 };
424 
425 #endif
426