xref: /openbmc/linux/include/uapi/linux/io_uring.h (revision 29e1c1ad3ff7f345d80c7b81b08175f5a8c84122)
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  * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
164  * command flags for POLL_ADD are stored in sqe->len.
165  *
166  * IORING_POLL_ADD_MULTI	Multishot poll. Sets IORING_CQE_F_MORE if
167  *				the poll handler will continue to report
168  *				CQEs on behalf of the same SQE.
169  *
170  * IORING_POLL_UPDATE		Update existing poll request, matching
171  *				sqe->addr as the old user_data field.
172  */
173 #define IORING_POLL_ADD_MULTI	(1U << 0)
174 #define IORING_POLL_UPDATE_EVENTS	(1U << 1)
175 #define IORING_POLL_UPDATE_USER_DATA	(1U << 2)
176 
177 /*
178  * IO completion data structure (Completion Queue Entry)
179  */
180 struct io_uring_cqe {
181 	__u64	user_data;	/* sqe->data submission passed back */
182 	__s32	res;		/* result code for this event */
183 	__u32	flags;
184 };
185 
186 /*
187  * cqe->flags
188  *
189  * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID
190  * IORING_CQE_F_MORE	If set, parent SQE will generate more CQE entries
191  */
192 #define IORING_CQE_F_BUFFER		(1U << 0)
193 #define IORING_CQE_F_MORE		(1U << 1)
194 
195 enum {
196 	IORING_CQE_BUFFER_SHIFT		= 16,
197 };
198 
199 /*
200  * Magic offsets for the application to mmap the data it needs
201  */
202 #define IORING_OFF_SQ_RING		0ULL
203 #define IORING_OFF_CQ_RING		0x8000000ULL
204 #define IORING_OFF_SQES			0x10000000ULL
205 
206 /*
207  * Filled with the offset for mmap(2)
208  */
209 struct io_sqring_offsets {
210 	__u32 head;
211 	__u32 tail;
212 	__u32 ring_mask;
213 	__u32 ring_entries;
214 	__u32 flags;
215 	__u32 dropped;
216 	__u32 array;
217 	__u32 resv1;
218 	__u64 resv2;
219 };
220 
221 /*
222  * sq_ring->flags
223  */
224 #define IORING_SQ_NEED_WAKEUP	(1U << 0) /* needs io_uring_enter wakeup */
225 #define IORING_SQ_CQ_OVERFLOW	(1U << 1) /* CQ ring is overflown */
226 
227 struct io_cqring_offsets {
228 	__u32 head;
229 	__u32 tail;
230 	__u32 ring_mask;
231 	__u32 ring_entries;
232 	__u32 overflow;
233 	__u32 cqes;
234 	__u32 flags;
235 	__u32 resv1;
236 	__u64 resv2;
237 };
238 
239 /*
240  * cq_ring->flags
241  */
242 
243 /* disable eventfd notifications */
244 #define IORING_CQ_EVENTFD_DISABLED	(1U << 0)
245 
246 /*
247  * io_uring_enter(2) flags
248  */
249 #define IORING_ENTER_GETEVENTS	(1U << 0)
250 #define IORING_ENTER_SQ_WAKEUP	(1U << 1)
251 #define IORING_ENTER_SQ_WAIT	(1U << 2)
252 #define IORING_ENTER_EXT_ARG	(1U << 3)
253 
254 /*
255  * Passed in for io_uring_setup(2). Copied back with updated info on success
256  */
257 struct io_uring_params {
258 	__u32 sq_entries;
259 	__u32 cq_entries;
260 	__u32 flags;
261 	__u32 sq_thread_cpu;
262 	__u32 sq_thread_idle;
263 	__u32 features;
264 	__u32 wq_fd;
265 	__u32 resv[3];
266 	struct io_sqring_offsets sq_off;
267 	struct io_cqring_offsets cq_off;
268 };
269 
270 /*
271  * io_uring_params->features flags
272  */
273 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
274 #define IORING_FEAT_NODROP		(1U << 1)
275 #define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
276 #define IORING_FEAT_RW_CUR_POS		(1U << 3)
277 #define IORING_FEAT_CUR_PERSONALITY	(1U << 4)
278 #define IORING_FEAT_FAST_POLL		(1U << 5)
279 #define IORING_FEAT_POLL_32BITS 	(1U << 6)
280 #define IORING_FEAT_SQPOLL_NONFIXED	(1U << 7)
281 #define IORING_FEAT_EXT_ARG		(1U << 8)
282 #define IORING_FEAT_NATIVE_WORKERS	(1U << 9)
283 
284 /*
285  * io_uring_register(2) opcodes and arguments
286  */
287 enum {
288 	IORING_REGISTER_BUFFERS			= 0,
289 	IORING_UNREGISTER_BUFFERS		= 1,
290 	IORING_REGISTER_FILES			= 2,
291 	IORING_UNREGISTER_FILES			= 3,
292 	IORING_REGISTER_EVENTFD			= 4,
293 	IORING_UNREGISTER_EVENTFD		= 5,
294 	IORING_REGISTER_FILES_UPDATE		= 6,
295 	IORING_REGISTER_EVENTFD_ASYNC		= 7,
296 	IORING_REGISTER_PROBE			= 8,
297 	IORING_REGISTER_PERSONALITY		= 9,
298 	IORING_UNREGISTER_PERSONALITY		= 10,
299 	IORING_REGISTER_RESTRICTIONS		= 11,
300 	IORING_REGISTER_ENABLE_RINGS		= 12,
301 	IORING_REGISTER_RSRC			= 13,
302 	IORING_REGISTER_RSRC_UPDATE		= 14,
303 
304 	/* this goes last */
305 	IORING_REGISTER_LAST
306 };
307 
308 /* deprecated, see struct io_uring_rsrc_update */
309 struct io_uring_files_update {
310 	__u32 offset;
311 	__u32 resv;
312 	__aligned_u64 /* __s32 * */ fds;
313 };
314 
315 enum {
316 	IORING_RSRC_FILE		= 0,
317 	IORING_RSRC_BUFFER		= 1,
318 };
319 
320 struct io_uring_rsrc_register {
321 	__u32 type;
322 	__u32 nr;
323 	__aligned_u64 data;
324 	__aligned_u64 tags;
325 };
326 
327 struct io_uring_rsrc_update {
328 	__u32 offset;
329 	__u32 resv;
330 	__aligned_u64 data;
331 };
332 
333 struct io_uring_rsrc_update2 {
334 	__u32 offset;
335 	__u32 resv;
336 	__aligned_u64 data;
337 	__aligned_u64 tags;
338 	__u32 type;
339 	__u32 nr;
340 };
341 
342 /* Skip updating fd indexes set to this value in the fd table */
343 #define IORING_REGISTER_FILES_SKIP	(-2)
344 
345 #define IO_URING_OP_SUPPORTED	(1U << 0)
346 
347 struct io_uring_probe_op {
348 	__u8 op;
349 	__u8 resv;
350 	__u16 flags;	/* IO_URING_OP_* flags */
351 	__u32 resv2;
352 };
353 
354 struct io_uring_probe {
355 	__u8 last_op;	/* last opcode supported */
356 	__u8 ops_len;	/* length of ops[] array below */
357 	__u16 resv;
358 	__u32 resv2[3];
359 	struct io_uring_probe_op ops[0];
360 };
361 
362 struct io_uring_restriction {
363 	__u16 opcode;
364 	union {
365 		__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
366 		__u8 sqe_op;      /* IORING_RESTRICTION_SQE_OP */
367 		__u8 sqe_flags;   /* IORING_RESTRICTION_SQE_FLAGS_* */
368 	};
369 	__u8 resv;
370 	__u32 resv2[3];
371 };
372 
373 /*
374  * io_uring_restriction->opcode values
375  */
376 enum {
377 	/* Allow an io_uring_register(2) opcode */
378 	IORING_RESTRICTION_REGISTER_OP		= 0,
379 
380 	/* Allow an sqe opcode */
381 	IORING_RESTRICTION_SQE_OP		= 1,
382 
383 	/* Allow sqe flags */
384 	IORING_RESTRICTION_SQE_FLAGS_ALLOWED	= 2,
385 
386 	/* Require sqe flags (these flags must be set on each submission) */
387 	IORING_RESTRICTION_SQE_FLAGS_REQUIRED	= 3,
388 
389 	IORING_RESTRICTION_LAST
390 };
391 
392 struct io_uring_getevents_arg {
393 	__u64	sigmask;
394 	__u32	sigmask_sz;
395 	__u32	pad;
396 	__u64	ts;
397 };
398 
399 #endif
400