2 * Copyright (c) 2016-2019 Cisco and/or its affiliates.
3 * Copyright (c) 2019 Arm Limited
4 * Copyright (c) 2010-2017 Intel Corporation and/or its affiliates.
5 * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
6 * Inspired from DPDK rte_ring.h (SPSC only) (derived from freebsd bufring.h).
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at:
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
19 #ifndef __included_ssvm_fifo_h__
20 #define __included_ssvm_fifo_h__
22 #include <vppinfra/clib.h>
23 #include <vppinfra/vec.h>
24 #include <vppinfra/pool.h>
25 #include <vppinfra/format.h>
26 #include <svm/fifo_types.h>
28 #define OOO_SEGMENT_INVALID_INDEX ((u32)~0)
29 #define SVM_FIFO_INVALID_SESSION_INDEX ((u32)~0)
30 #define SVM_FIFO_INVALID_INDEX ((u32)~0)
32 typedef enum svm_fifo_deq_ntf_
34 SVM_FIFO_NO_DEQ_NOTIF = 0, /**< No notification requested */
35 SVM_FIFO_WANT_DEQ_NOTIF = 1, /**< Notify on dequeue */
36 SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL = 2, /**< Notify on transition from full */
37 SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY = 4, /**< Notify on transition to empty */
40 typedef enum svm_fifo_flag_
42 SVM_FIFO_F_LL_TRACKED = 1 << 0,
52 typedef struct svm_fifo_seg_
59 #define svm_fifo_trace_add(_f, _s, _l, _t) \
61 svm_fifo_trace_elem_t *trace_elt; \
62 vec_add2(_f->trace, trace_elt, 1); \
63 trace_elt->offset = _s; \
64 trace_elt->len = _l; \
65 trace_elt->action = _t; \
68 #define svm_fifo_trace_add(_f, _s, _l, _t)
71 u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
72 u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);
75 * Load head and tail optimized for consumer
80 f_load_head_tail_cons (svm_fifo_t * f, u32 * head, u32 * tail)
82 /* load-relaxed: consumer owned index */
84 /* load-acq: consumer foreign index (paired with store-rel in producer) */
85 *tail = clib_atomic_load_acq_n (&f->tail);
88 /** Load head and tail optimized for producer
93 f_load_head_tail_prod (svm_fifo_t * f, u32 * head, u32 * tail)
95 /* load relaxed: producer owned index */
97 /* load-acq: producer foreign index (paired with store-rel in consumer) */
98 *head = clib_atomic_load_acq_n (&f->head);
102 * Load head and tail independent of producer/consumer role
107 f_load_head_tail_all_acq (svm_fifo_t * f, u32 * head, u32 * tail)
109 /* load-acq : consumer foreign index (paired with store-rel) */
110 *tail = clib_atomic_load_acq_n (&f->tail);
111 /* load-acq : producer foriegn index (paired with store-rel) */
112 *head = clib_atomic_load_acq_n (&f->head);
116 * Fifo current size, i.e., number of bytes enqueued
121 f_cursize (svm_fifo_t * f, u32 head, u32 tail)
127 * Fifo free bytes, i.e., number of free bytes
132 f_free_count (svm_fifo_t * f, u32 head, u32 tail)
134 return (f->size - f_cursize (f, head, tail));
138 f_chunk_end (svm_fifo_chunk_t * c)
140 return c->start_byte + c->length;
144 f_pos_lt (u32 a, u32 b)
146 return ((i32) (a - b) < 0);
150 f_pos_leq (u32 a, u32 b)
152 return ((i32) (a - b) <= 0);
156 f_pos_gt (u32 a, u32 b)
158 return ((i32) (a - b) > 0);
162 f_pos_geq (u32 a, u32 b)
164 return ((i32) (a - b) >= 0);
168 f_chunk_includes_pos (svm_fifo_chunk_t * c, u32 pos)
170 return (f_pos_geq (pos, c->start_byte)
171 && f_pos_lt (pos, c->start_byte + c->length));
175 * Create fifo of requested size
177 * Allocates fifo on current heap.
179 * @param size data size in bytes for fifo to be allocated. Will be
180 * rounded to the next highest power-of-two value.
181 * @return pointer to new fifo
183 svm_fifo_t *svm_fifo_alloc (u32 size);
188 * @param size size for fifo
190 void svm_fifo_init (svm_fifo_t * f, u32 size);
192 * Allocate a fifo chunk on heap
194 * If the chunk is allocated on a fifo segment, this should be called
195 * with the segment's heap pushed.
197 * @param size chunk size in bytes. Will be rounded to the next highest
199 * @return new chunk or 0 if alloc failed
201 svm_fifo_chunk_t *svm_fifo_chunk_alloc (u32 size);
203 * Grow fifo size by adding chunk to chunk list
205 * If fifos are allocated on a segment, this should be called with
206 * the segment's heap pushed.
208 * @param f fifo to be extended
209 * @param c chunk or linked list of chunks to be added
211 void svm_fifo_add_chunk (svm_fifo_t * f, svm_fifo_chunk_t * c);
212 int svm_fifo_fill_chunk_list (svm_fifo_t * f);
213 void svm_fifo_init_ooo_lookup (svm_fifo_t * f, u8 ooo_type);
215 * Free fifo and associated state
219 void svm_fifo_free (svm_fifo_t * f);
221 * Cleanup fifo chunk lookup rb tree
223 * The rb tree is allocated in segment heap so this should be called
226 * @param f fifo to cleanup
228 void svm_fifo_free_chunk_lookup (svm_fifo_t * f);
230 * Cleanup fifo ooo data
232 * The ooo data is allocated in producer process memory. The fifo
233 * segment heap should not be pushed.
235 * @param f fifo to cleanup
237 void svm_fifo_free_ooo_data (svm_fifo_t * f);
239 * Init fifo head and tail
242 * @param head head value that will be matched to a chunk
243 * @param tail tail value that will be matched to a chunk
245 void svm_fifo_init_pointers (svm_fifo_t * f, u32 head, u32 tail);
249 * Clones single/default chunk fifo. It does not work for fifos with
252 void svm_fifo_clone (svm_fifo_t * df, svm_fifo_t * sf);
254 * Enqueue data to fifo
256 * Data is enqueued and tail pointer is updated atomically. If the new data
257 * enqueued partly overlaps or "touches" an out-of-order segment, said segment
258 * is "consumed" and the number of bytes returned is appropriately updated.
261 * @param len length of data to copy
262 * @param src buffer from where to copy the data
263 * @return number of contiguous bytes that can be consumed or error
265 int svm_fifo_enqueue (svm_fifo_t * f, u32 len, const u8 * src);
267 * Enqueue data to fifo with offset
269 * Data is enqueued without updating tail pointer. Instead, an out-of-order
270 * list of segments is generated and maintained. Fifo takes care of coalescing
271 * contiguous or overlapping segments.
274 * @param offset offset at which to copy the data
275 * @param len len of data to copy
276 * @param src buffer from where to copy the data
277 * @return 0 if enqueue was successful, error otherwise
279 int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 len,
283 * Advance tail pointer
285 * Useful for moving tail pointer after external enqueue.
288 * @param len number of bytes to add to tail
290 void svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 len);
292 * Overwrite fifo head with new data
294 * This should be typically used by dgram transport protocols that need
295 * to update the dgram header after dequeueing a chunk of data. It assumes
296 * that the dgram header is at most spread over two chunks.
299 * @param src src of new data
300 * @param len length of new data
302 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * src, u32 len);
304 * Dequeue data from fifo
306 * Data is dequeued to consumer provided buffer and head is atomically
310 * @param len length of data to dequeue
311 * @param dst buffer to where to dequeue the data
312 * @return number of bytes dequeued or error
314 int svm_fifo_dequeue (svm_fifo_t * f, u32 len, u8 * dst);
316 * Peek data from fifo
318 * Data is copied from requested offset into provided dst buffer. Head is
322 * @param offset offset from which to copy the data
323 * @param len length of data to copy
324 * @param dst buffer to where to dequeue the data
325 * @return number of bytes peeked
327 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 len, u8 * dst);
329 * Dequeue and drop bytes from fifo
331 * Advances fifo head by requested amount of bytes.
334 * @param len number of bytes to drop
335 * @return number of bytes dropped
337 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 len);
339 * Dequeue and drop all bytes from fifo
341 * Advances head to tail position.
345 void svm_fifo_dequeue_drop_all (svm_fifo_t * f);
346 int svm_fifo_segments (svm_fifo_t * f, svm_fifo_seg_t * fs);
347 void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_seg_t * fs);
349 * Add io events subscriber to list
352 * @param sub subscriber opaque index (typically app worker index)
354 void svm_fifo_add_subscriber (svm_fifo_t * f, u8 sub);
356 * Remove io events subscriber form list
359 * @param sub subscriber index to be removed
361 void svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber);
363 * Number of out-of-order segments for fifo
366 * @return number of out of order segments
368 u32 svm_fifo_n_ooo_segments (svm_fifo_t * f);
370 * First out-of-order segment for fifo
373 * @return first out-of-order segment for fifo
375 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
377 * Check if fifo is sane. Debug only.
380 * @return 1 if sane, 0 otherwise
382 u8 svm_fifo_is_sane (svm_fifo_t * f);
383 u32 svm_fifo_n_chunks (svm_fifo_t * f);
384 format_function_t format_svm_fifo;
387 * Fifo max bytes to dequeue optimized for consumer
390 * @return max number of bytes that can be dequeued
393 svm_fifo_max_dequeue_cons (svm_fifo_t * f)
396 f_load_head_tail_cons (f, &head, &tail);
397 return f_cursize (f, head, tail);
401 * Fifo max bytes to dequeue optimized for producer
404 * @return max number of bytes that can be dequeued
407 svm_fifo_max_dequeue_prod (svm_fifo_t * f)
410 f_load_head_tail_prod (f, &head, &tail);
411 return f_cursize (f, head, tail);
415 * Fifo max bytes to dequeue
417 * Note: use producer or consumer specific functions for performance:
418 * @ref svm_fifo_max_dequeue_cons (svm_fifo_t *f)
419 * @ref svm_fifo_max_dequeue_prod (svm_fifo_t *f)
422 svm_fifo_max_dequeue (svm_fifo_t * f)
425 f_load_head_tail_all_acq (f, &head, &tail);
426 return f_cursize (f, head, tail);
430 * Check if fifo is full optimized for producer
433 * @return 1 if fifo is full 0 otherwise
436 svm_fifo_is_full_prod (svm_fifo_t * f)
438 return (svm_fifo_max_dequeue_prod (f) == f->size);
441 /* Check if fifo is full.
443 * Note: use producer or consumer specific functions for performance.
444 * @ref svm_fifo_is_full_prod (svm_fifo_t * f)
445 * add cons version if needed
448 svm_fifo_is_full (svm_fifo_t * f)
450 return (svm_fifo_max_dequeue (f) == f->size);
454 * Check if fifo is empty optimized for consumer
457 * @return 1 if fifo is empty 0 otherwise
460 svm_fifo_is_empty_cons (svm_fifo_t * f)
462 return (svm_fifo_max_dequeue_cons (f) == 0);
466 * Check if fifo is empty optimized for producer
469 * @return 1 if fifo is empty 0 otherwise
472 svm_fifo_is_empty_prod (svm_fifo_t * f)
474 return (svm_fifo_max_dequeue_prod (f) == 0);
478 * Check if fifo is empty
480 * Note: use producer or consumer specific functions for perfomance.
481 * @ref svm_fifo_is_empty_cons (svm_fifo_t * f)
482 * @ref svm_fifo_is_empty_prod (svm_fifo_t * f)
485 svm_fifo_is_empty (svm_fifo_t * f)
487 return (svm_fifo_max_dequeue (f) == 0);
491 * Check if fifo is wrapped
494 * @return 1 if 'normalized' head is ahead of tail
497 svm_fifo_is_wrapped (svm_fifo_t * f)
500 f_load_head_tail_all_acq (f, &head, &tail);
505 * Maximum number of bytes that can be enqueued into fifo
507 * Optimized for producer
510 * @return max number of bytes that can be enqueued into fifo
513 svm_fifo_max_enqueue_prod (svm_fifo_t * f)
516 f_load_head_tail_prod (f, &head, &tail);
517 return f_free_count (f, head, tail);
520 /* Maximum number of bytes that can be enqueued into fifo
522 * Note: use producer or consumer specific functions for performance.
523 * @ref svm_fifo_max_enqueue_prod (svm_fifo_t *f)
524 * add consumer specific version if needed.
527 svm_fifo_max_enqueue (svm_fifo_t * f)
530 f_load_head_tail_all_acq (f, &head, &tail);
531 return f_free_count (f, head, tail);
535 * Max contiguous chunk of data that can be read.
537 * Should only be called by consumers.
539 u32 svm_fifo_max_read_chunk (svm_fifo_t * f);
542 * Max contiguous chunk of data that can be written
544 * Should only be called by producers
546 u32 svm_fifo_max_write_chunk (svm_fifo_t * f);
548 static inline svm_fifo_chunk_t *
549 svm_fifo_head_chunk (svm_fifo_t * f)
551 return f->head_chunk;
555 svm_fifo_head (svm_fifo_t * f)
559 /* load-relaxed: consumer owned index */
560 return (f->head_chunk->data + (f->head - f->head_chunk->start_byte));
563 static inline svm_fifo_chunk_t *
564 svm_fifo_tail_chunk (svm_fifo_t * f)
566 return f->tail_chunk;
570 svm_fifo_tail (svm_fifo_t * f)
572 /* load-relaxed: producer owned index */
573 return (f->tail_chunk->data + (f->tail - f->tail_chunk->start_byte));
577 svm_fifo_n_subscribers (svm_fifo_t * f)
579 return f->n_subscribers;
583 * Check if fifo has out-of-order data
586 * @return 1 if fifo has ooo data, 0 otherwise
589 svm_fifo_has_ooo_data (svm_fifo_t * f)
591 return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
594 static inline ooo_segment_t *
595 svm_fifo_newest_ooo_segment (svm_fifo_t * f)
597 if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
599 return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
603 svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f)
605 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
609 ooo_segment_offset_prod (svm_fifo_t * f, ooo_segment_t * s)
612 /* load-relaxed: producer owned index */
615 return (s->start - tail);
619 ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s)
625 svm_fifo_size (svm_fifo_t * f)
631 svm_fifo_set_size (svm_fifo_t * f, u32 size)
637 * Check if fifo has io event
640 * @return 1 if fifo has event, 0 otherwise
643 svm_fifo_has_event (svm_fifo_t * f)
649 * Set fifo event flag.
651 * Forces release semantics.
654 * @return 1 if flag was not set, 0 otherwise
657 svm_fifo_set_event (svm_fifo_t * f)
659 return !clib_atomic_swap_rel_n (&f->has_event, 1);
663 * Unset fifo event flag.
665 * Forces acquire semantics
670 svm_fifo_unset_event (svm_fifo_t * f)
672 clib_atomic_swap_acq_n (&f->has_event, 0);
676 * Set specific want notification flag
678 * For list of flags see @ref svm_fifo_deq_ntf_t
681 * @param ntf_type type of notification requested
684 svm_fifo_add_want_deq_ntf (svm_fifo_t * f, u8 ntf_type)
686 f->want_deq_ntf |= ntf_type;
690 * Clear specific want notification flag
692 * For list of flags see @ref svm_fifo_ntf_t
695 * @param ntf_type type of notification to be cleared
698 svm_fifo_del_want_deq_ntf (svm_fifo_t * f, u8 ntf_type)
700 f->want_deq_ntf &= ~ntf_type;
704 * Clear the want notification flag and set has notification
706 * Should be used after enqueuing an event. This clears the
707 * SVM_FIFO_WANT_NOTIF flag but it does not clear
708 * SVM_FIFO_WANT_NOTIF_IF_FULL. If the latter was set, has_ntf is
709 * set to avoid enqueueing events for for all dequeue operations until
710 * it is manually cleared.
715 svm_fifo_clear_deq_ntf (svm_fifo_t * f)
717 /* Set the flag if want_notif_if_full was the only ntf requested */
718 f->has_deq_ntf = f->want_deq_ntf == SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL;
719 svm_fifo_del_want_deq_ntf (f, SVM_FIFO_WANT_DEQ_NOTIF);
723 * Clear has notification flag
725 * The fifo generates only one event per SVM_FIFO_WANT_NOTIF_IF_FULL
726 * request and sets has_ntf. To received new events the flag must be
727 * cleared using this function.
732 svm_fifo_reset_has_deq_ntf (svm_fifo_t * f)
738 * Check if fifo needs dequeue notification
740 * Determines based on notification request flags and state of the fifo if
741 * an event should be generated.
744 * @param n_last_deq number of bytes last dequeued
745 * @return 1 if event should be generated, 0 otherwise
748 svm_fifo_needs_deq_ntf (svm_fifo_t * f, u32 n_last_deq)
750 u8 want_ntf = f->want_deq_ntf;
752 if (PREDICT_TRUE (want_ntf == SVM_FIFO_NO_DEQ_NOTIF))
754 else if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF)
756 if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL)
758 u32 max_deq = svm_fifo_max_dequeue_cons (f);
760 if (!f->has_deq_ntf && max_deq < size && max_deq + n_last_deq >= size)
763 if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY)
765 if (!f->has_deq_ntf && svm_fifo_is_empty (f))
771 #endif /* __included_ssvm_fifo_h__ */
774 * fd.io coding-style-patch-verification: ON
777 * eval: (c-set-style "gnu")