1 /* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
3 * Header file for the io_uring interface.
5 * Copyright (C) 2019 Jens Axboe
6 * Copyright (C) 2019 Christoph Hellwig
8 #ifndef LINUX_IO_URING_H
9 #define LINUX_IO_URING_H
12 #include <linux/types.h>
15 * IO submission data structure (Submission Queue Entry)
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 */
23 __u64 off; /* offset into file */
27 __u64 addr; /* pointer to buffer or iovecs */
30 __u32 len; /* buffer size or number of iovecs */
32 __kernel_rwf_t rw_flags;
34 __u16 poll_events; /* compatibility */
35 __u32 poll32_events; /* word-reversed for BE */
36 __u32 sync_range_flags;
49 __u64 user_data; /* data to be passed back at completion time */
50 /* pack this to avoid bogus arm OABI complaints */
52 /* index into fixed buffers, if used */
54 /* for grouped buffer selection */
56 } __attribute__((packed));
57 /* personality to use, if used */
70 IOSQE_IO_HARDLINK_BIT,
72 IOSQE_BUFFER_SELECT_BIT,
73 IOSQE_CQE_SKIP_SUCCESS_BIT,
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)
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)
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)
95 * io_uring_setup() flags
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 */
111 IORING_OP_READ_FIXED,
112 IORING_OP_WRITE_FIXED,
114 IORING_OP_POLL_REMOVE,
115 IORING_OP_SYNC_FILE_RANGE,
119 IORING_OP_TIMEOUT_REMOVE,
121 IORING_OP_ASYNC_CANCEL,
122 IORING_OP_LINK_TIMEOUT,
127 IORING_OP_FILES_UPDATE,
138 IORING_OP_PROVIDE_BUFFERS,
139 IORING_OP_REMOVE_BUFFERS,
149 /* this goes last, obviously */
156 #define IORING_FSYNC_DATASYNC (1U << 0)
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)
171 * extends splice(2) flags
173 #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
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.
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.
183 * IORING_POLL_UPDATE Update existing poll request, matching
184 * sqe->addr as the old user_data field.
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)
191 * IO completion data structure (Completion Queue Entry)
193 struct io_uring_cqe {
194 __u64 user_data; /* sqe->data submission passed back */
195 __s32 res; /* result code for this event */
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 * IORING_CQE_F_MSG If set, CQE was generated with IORING_OP_MSG_RING
206 #define IORING_CQE_F_BUFFER (1U << 0)
207 #define IORING_CQE_F_MORE (1U << 1)
208 #define IORING_CQE_F_MSG (1U << 2)
211 IORING_CQE_BUFFER_SHIFT = 16,
215 * Magic offsets for the application to mmap the data it needs
217 #define IORING_OFF_SQ_RING 0ULL
218 #define IORING_OFF_CQ_RING 0x8000000ULL
219 #define IORING_OFF_SQES 0x10000000ULL
222 * Filled with the offset for mmap(2)
224 struct io_sqring_offsets {
239 #define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
240 #define IORING_SQ_CQ_OVERFLOW (1U << 1) /* CQ ring is overflown */
242 struct io_cqring_offsets {
258 /* disable eventfd notifications */
259 #define IORING_CQ_EVENTFD_DISABLED (1U << 0)
262 * io_uring_enter(2) flags
264 #define IORING_ENTER_GETEVENTS (1U << 0)
265 #define IORING_ENTER_SQ_WAKEUP (1U << 1)
266 #define IORING_ENTER_SQ_WAIT (1U << 2)
267 #define IORING_ENTER_EXT_ARG (1U << 3)
268 #define IORING_ENTER_REGISTERED_RING (1U << 4)
271 * Passed in for io_uring_setup(2). Copied back with updated info on success
273 struct io_uring_params {
278 __u32 sq_thread_idle;
282 struct io_sqring_offsets sq_off;
283 struct io_cqring_offsets cq_off;
287 * io_uring_params->features flags
289 #define IORING_FEAT_SINGLE_MMAP (1U << 0)
290 #define IORING_FEAT_NODROP (1U << 1)
291 #define IORING_FEAT_SUBMIT_STABLE (1U << 2)
292 #define IORING_FEAT_RW_CUR_POS (1U << 3)
293 #define IORING_FEAT_CUR_PERSONALITY (1U << 4)
294 #define IORING_FEAT_FAST_POLL (1U << 5)
295 #define IORING_FEAT_POLL_32BITS (1U << 6)
296 #define IORING_FEAT_SQPOLL_NONFIXED (1U << 7)
297 #define IORING_FEAT_EXT_ARG (1U << 8)
298 #define IORING_FEAT_NATIVE_WORKERS (1U << 9)
299 #define IORING_FEAT_RSRC_TAGS (1U << 10)
300 #define IORING_FEAT_CQE_SKIP (1U << 11)
303 * io_uring_register(2) opcodes and arguments
306 IORING_REGISTER_BUFFERS = 0,
307 IORING_UNREGISTER_BUFFERS = 1,
308 IORING_REGISTER_FILES = 2,
309 IORING_UNREGISTER_FILES = 3,
310 IORING_REGISTER_EVENTFD = 4,
311 IORING_UNREGISTER_EVENTFD = 5,
312 IORING_REGISTER_FILES_UPDATE = 6,
313 IORING_REGISTER_EVENTFD_ASYNC = 7,
314 IORING_REGISTER_PROBE = 8,
315 IORING_REGISTER_PERSONALITY = 9,
316 IORING_UNREGISTER_PERSONALITY = 10,
317 IORING_REGISTER_RESTRICTIONS = 11,
318 IORING_REGISTER_ENABLE_RINGS = 12,
320 /* extended with tagging */
321 IORING_REGISTER_FILES2 = 13,
322 IORING_REGISTER_FILES_UPDATE2 = 14,
323 IORING_REGISTER_BUFFERS2 = 15,
324 IORING_REGISTER_BUFFERS_UPDATE = 16,
326 /* set/clear io-wq thread affinities */
327 IORING_REGISTER_IOWQ_AFF = 17,
328 IORING_UNREGISTER_IOWQ_AFF = 18,
330 /* set/get max number of io-wq workers */
331 IORING_REGISTER_IOWQ_MAX_WORKERS = 19,
333 /* register/unregister io_uring fd with the ring */
334 IORING_REGISTER_RING_FDS = 20,
335 IORING_UNREGISTER_RING_FDS = 21,
341 /* io-wq worker categories */
347 /* deprecated, see struct io_uring_rsrc_update */
348 struct io_uring_files_update {
351 __aligned_u64 /* __s32 * */ fds;
354 struct io_uring_rsrc_register {
362 struct io_uring_rsrc_update {
368 struct io_uring_rsrc_update2 {
377 /* Skip updating fd indexes set to this value in the fd table */
378 #define IORING_REGISTER_FILES_SKIP (-2)
380 #define IO_URING_OP_SUPPORTED (1U << 0)
382 struct io_uring_probe_op {
385 __u16 flags; /* IO_URING_OP_* flags */
389 struct io_uring_probe {
390 __u8 last_op; /* last opcode supported */
391 __u8 ops_len; /* length of ops[] array below */
394 struct io_uring_probe_op ops[0];
397 struct io_uring_restriction {
400 __u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
401 __u8 sqe_op; /* IORING_RESTRICTION_SQE_OP */
402 __u8 sqe_flags; /* IORING_RESTRICTION_SQE_FLAGS_* */
409 * io_uring_restriction->opcode values
412 /* Allow an io_uring_register(2) opcode */
413 IORING_RESTRICTION_REGISTER_OP = 0,
415 /* Allow an sqe opcode */
416 IORING_RESTRICTION_SQE_OP = 1,
418 /* Allow sqe flags */
419 IORING_RESTRICTION_SQE_FLAGS_ALLOWED = 2,
421 /* Require sqe flags (these flags must be set on each submission) */
422 IORING_RESTRICTION_SQE_FLAGS_REQUIRED = 3,
424 IORING_RESTRICTION_LAST
427 struct io_uring_getevents_arg {