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 * Ensure the whole fifo size is writeable
205 * Allocates enough chunks to cover the whole fifo size.
209 int svm_fifo_fill_chunk_list (svm_fifo_t * f);
211 * Initialize rbtrees used for ooo lookups
214 * @param ooo_type type of ooo operation (0 enqueue, 1 dequeue)
216 void svm_fifo_init_ooo_lookup (svm_fifo_t * f, u8 ooo_type);
218 * Free fifo and associated state
222 void svm_fifo_free (svm_fifo_t * f);
224 * Cleanup fifo chunk lookup rb tree
226 * The rb tree is allocated in segment heap so this should be called
229 * @param f fifo to cleanup
231 void svm_fifo_free_chunk_lookup (svm_fifo_t * f);
233 * Cleanup fifo ooo data
235 * The ooo data is allocated in producer process memory. The fifo
236 * segment heap should not be pushed.
238 * @param f fifo to cleanup
240 void svm_fifo_free_ooo_data (svm_fifo_t * f);
242 * Init fifo head and tail
245 * @param head head value that will be matched to a chunk
246 * @param tail tail value that will be matched to a chunk
248 void svm_fifo_init_pointers (svm_fifo_t * f, u32 head, u32 tail);
252 * Clones single/default chunk fifo. It does not work for fifos with
255 void svm_fifo_clone (svm_fifo_t * df, svm_fifo_t * sf);
257 * Enqueue data to fifo
259 * Data is enqueued and tail pointer is updated atomically. If the new data
260 * enqueued partly overlaps or "touches" an out-of-order segment, said segment
261 * is "consumed" and the number of bytes returned is appropriately updated.
264 * @param len length of data to copy
265 * @param src buffer from where to copy the data
266 * @return number of contiguous bytes that can be consumed or error
268 int svm_fifo_enqueue (svm_fifo_t * f, u32 len, const u8 * src);
270 * Enqueue data to fifo with offset
272 * Data is enqueued without updating tail pointer. Instead, an out-of-order
273 * list of segments is generated and maintained. Fifo takes care of coalescing
274 * contiguous or overlapping segments.
277 * @param offset offset at which to copy the data
278 * @param len len of data to copy
279 * @param src buffer from where to copy the data
280 * @return 0 if enqueue was successful, error otherwise
282 int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 len,
286 * Advance tail pointer
288 * Useful for moving tail pointer after external enqueue.
291 * @param len number of bytes to add to tail
293 void svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 len);
295 * Overwrite fifo head with new data
297 * This should be typically used by dgram transport protocols that need
298 * to update the dgram header after dequeueing a chunk of data. It assumes
299 * that the dgram header is at most spread over two chunks.
302 * @param src src of new data
303 * @param len length of new data
305 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * src, u32 len);
307 * Dequeue data from fifo
309 * Data is dequeued to consumer provided buffer and head is atomically
313 * @param len length of data to dequeue
314 * @param dst buffer to where to dequeue the data
315 * @return number of bytes dequeued or error
317 int svm_fifo_dequeue (svm_fifo_t * f, u32 len, u8 * dst);
319 * Peek data from fifo
321 * Data is copied from requested offset into provided dst buffer. Head is
325 * @param offset offset from which to copy the data
326 * @param len length of data to copy
327 * @param dst buffer to where to dequeue the data
328 * @return number of bytes peeked
330 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 len, u8 * dst);
332 * Dequeue and drop bytes from fifo
334 * Advances fifo head by requested amount of bytes.
337 * @param len number of bytes to drop
338 * @return number of bytes dropped
340 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 len);
342 * Dequeue and drop all bytes from fifo
344 * Advances head to tail position.
348 void svm_fifo_dequeue_drop_all (svm_fifo_t * f);
349 int svm_fifo_segments (svm_fifo_t * f, svm_fifo_seg_t * fs);
350 void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_seg_t * fs);
352 * Add io events subscriber to list
355 * @param sub subscriber opaque index (typically app worker index)
357 void svm_fifo_add_subscriber (svm_fifo_t * f, u8 sub);
359 * Remove io events subscriber form list
362 * @param sub subscriber index to be removed
364 void svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber);
366 * Number of out-of-order segments for fifo
369 * @return number of out of order segments
371 u32 svm_fifo_n_ooo_segments (svm_fifo_t * f);
373 * First out-of-order segment for fifo
376 * @return first out-of-order segment for fifo
378 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
380 * Check if fifo is sane. Debug only.
383 * @return 1 if sane, 0 otherwise
385 u8 svm_fifo_is_sane (svm_fifo_t * f);
387 * Number of chunks linked into the fifo
390 * @return number of chunks in fifo linked list
392 u32 svm_fifo_n_chunks (svm_fifo_t * f);
393 format_function_t format_svm_fifo;
396 * Fifo max bytes to dequeue optimized for consumer
399 * @return max number of bytes that can be dequeued
402 svm_fifo_max_dequeue_cons (svm_fifo_t * f)
405 f_load_head_tail_cons (f, &head, &tail);
406 return f_cursize (f, head, tail);
410 * Fifo max bytes to dequeue optimized for producer
413 * @return max number of bytes that can be dequeued
416 svm_fifo_max_dequeue_prod (svm_fifo_t * f)
419 f_load_head_tail_prod (f, &head, &tail);
420 return f_cursize (f, head, tail);
424 * Fifo max bytes to dequeue
426 * Note: use producer or consumer specific functions for performance:
427 * @ref svm_fifo_max_dequeue_cons (svm_fifo_t *f)
428 * @ref svm_fifo_max_dequeue_prod (svm_fifo_t *f)
431 svm_fifo_max_dequeue (svm_fifo_t * f)
434 f_load_head_tail_all_acq (f, &head, &tail);
435 return f_cursize (f, head, tail);
439 * Check if fifo is full optimized for producer
442 * @return 1 if fifo is full 0 otherwise
445 svm_fifo_is_full_prod (svm_fifo_t * f)
447 return (svm_fifo_max_dequeue_prod (f) == f->size);
450 /* Check if fifo is full.
452 * Note: use producer or consumer specific functions for performance.
453 * @ref svm_fifo_is_full_prod (svm_fifo_t * f)
454 * add cons version if needed
457 svm_fifo_is_full (svm_fifo_t * f)
459 return (svm_fifo_max_dequeue (f) == f->size);
463 * Check if fifo is empty optimized for consumer
466 * @return 1 if fifo is empty 0 otherwise
469 svm_fifo_is_empty_cons (svm_fifo_t * f)
471 return (svm_fifo_max_dequeue_cons (f) == 0);
475 * Check if fifo is empty optimized for producer
478 * @return 1 if fifo is empty 0 otherwise
481 svm_fifo_is_empty_prod (svm_fifo_t * f)
483 return (svm_fifo_max_dequeue_prod (f) == 0);
487 * Check if fifo is empty
489 * Note: use producer or consumer specific functions for perfomance.
490 * @ref svm_fifo_is_empty_cons (svm_fifo_t * f)
491 * @ref svm_fifo_is_empty_prod (svm_fifo_t * f)
494 svm_fifo_is_empty (svm_fifo_t * f)
496 return (svm_fifo_max_dequeue (f) == 0);
500 * Check if fifo is wrapped
503 * @return 1 if 'normalized' head is ahead of tail
506 svm_fifo_is_wrapped (svm_fifo_t * f)
509 f_load_head_tail_all_acq (f, &head, &tail);
514 * Maximum number of bytes that can be enqueued into fifo
516 * Optimized for producer
519 * @return max number of bytes that can be enqueued into fifo
522 svm_fifo_max_enqueue_prod (svm_fifo_t * f)
525 f_load_head_tail_prod (f, &head, &tail);
526 return f_free_count (f, head, tail);
529 /* Maximum number of bytes that can be enqueued into fifo
531 * Note: use producer or consumer specific functions for performance.
532 * @ref svm_fifo_max_enqueue_prod (svm_fifo_t *f)
533 * add consumer specific version if needed.
536 svm_fifo_max_enqueue (svm_fifo_t * f)
539 f_load_head_tail_all_acq (f, &head, &tail);
540 return f_free_count (f, head, tail);
544 * Max contiguous chunk of data that can be read.
546 * Should only be called by consumers.
548 u32 svm_fifo_max_read_chunk (svm_fifo_t * f);
551 * Max contiguous chunk of data that can be written
553 * Should only be called by producers
555 u32 svm_fifo_max_write_chunk (svm_fifo_t * f);
558 * Fifo head chunk getter
561 * @return head chunk pointer
563 static inline svm_fifo_chunk_t *
564 svm_fifo_head_chunk (svm_fifo_t * f)
566 return f->head_chunk;
570 * Fifo head pointer getter
573 * @return head pointer
576 svm_fifo_head (svm_fifo_t * f)
580 /* load-relaxed: consumer owned index */
581 return (f->head_chunk->data + (f->head - f->head_chunk->start_byte));
585 * Fifo tail chunk getter
588 * @return tail chunk pointer
590 static inline svm_fifo_chunk_t *
591 svm_fifo_tail_chunk (svm_fifo_t * f)
593 return f->tail_chunk;
597 * Fifo tail pointer getter
600 * @return tail pointer
603 svm_fifo_tail (svm_fifo_t * f)
605 /* load-relaxed: producer owned index */
606 return (f->tail_chunk->data + (f->tail - f->tail_chunk->start_byte));
610 * Fifo number of subscribers getter
613 * @return number of subscribers
616 svm_fifo_n_subscribers (svm_fifo_t * f)
618 return f->n_subscribers;
622 * Check if fifo has out-of-order data
625 * @return 1 if fifo has ooo data, 0 otherwise
628 svm_fifo_has_ooo_data (svm_fifo_t * f)
630 return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
633 static inline ooo_segment_t *
634 svm_fifo_newest_ooo_segment (svm_fifo_t * f)
636 if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
638 return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
642 svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f)
644 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
648 ooo_segment_offset_prod (svm_fifo_t * f, ooo_segment_t * s)
651 /* load-relaxed: producer owned index */
654 return (s->start - tail);
658 ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s)
664 svm_fifo_size (svm_fifo_t * f)
670 svm_fifo_set_size (svm_fifo_t * f, u32 size)
672 if (size > (1 << f->fs_hdr->max_log2_chunk_size))
674 fsh_virtual_mem_update (f->fs_hdr, f->slice_index, (int) f->size - size);
679 * Check if fifo has io event
682 * @return 1 if fifo has event, 0 otherwise
685 svm_fifo_has_event (svm_fifo_t * f)
691 * Set fifo event flag.
693 * Forces release semantics.
696 * @return 1 if flag was not set, 0 otherwise
699 svm_fifo_set_event (svm_fifo_t * f)
701 return !clib_atomic_swap_rel_n (&f->has_event, 1);
705 * Unset fifo event flag.
707 * Forces acquire semantics
712 svm_fifo_unset_event (svm_fifo_t * f)
714 clib_atomic_swap_acq_n (&f->has_event, 0);
718 * Set specific want notification flag
720 * For list of flags see @ref svm_fifo_deq_ntf_t
723 * @param ntf_type type of notification requested
726 svm_fifo_add_want_deq_ntf (svm_fifo_t * f, u8 ntf_type)
728 f->want_deq_ntf |= ntf_type;
732 * Clear specific want notification flag
734 * For list of flags see @ref svm_fifo_ntf_t
737 * @param ntf_type type of notification to be cleared
740 svm_fifo_del_want_deq_ntf (svm_fifo_t * f, u8 ntf_type)
742 f->want_deq_ntf &= ~ntf_type;
746 * Clear the want notification flag and set has notification
748 * Should be used after enqueuing an event. This clears the
749 * SVM_FIFO_WANT_NOTIF flag but it does not clear
750 * SVM_FIFO_WANT_NOTIF_IF_FULL. If the latter was set, has_ntf is
751 * set to avoid enqueueing events for for all dequeue operations until
752 * it is manually cleared.
757 svm_fifo_clear_deq_ntf (svm_fifo_t * f)
759 /* Set the flag if want_notif_if_full was the only ntf requested */
760 f->has_deq_ntf = f->want_deq_ntf == SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL;
761 svm_fifo_del_want_deq_ntf (f, SVM_FIFO_WANT_DEQ_NOTIF);
765 * Clear has notification flag
767 * The fifo generates only one event per SVM_FIFO_WANT_NOTIF_IF_FULL
768 * request and sets has_ntf. To received new events the flag must be
769 * cleared using this function.
774 svm_fifo_reset_has_deq_ntf (svm_fifo_t * f)
780 * Check if fifo needs dequeue notification
782 * Determines based on notification request flags and state of the fifo if
783 * an event should be generated.
786 * @param n_last_deq number of bytes last dequeued
787 * @return 1 if event should be generated, 0 otherwise
790 svm_fifo_needs_deq_ntf (svm_fifo_t * f, u32 n_last_deq)
792 u8 want_ntf = f->want_deq_ntf;
794 if (PREDICT_TRUE (want_ntf == SVM_FIFO_NO_DEQ_NOTIF))
796 else if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF)
798 if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL)
800 u32 max_deq = svm_fifo_max_dequeue_cons (f);
802 if (!f->has_deq_ntf && max_deq < size && max_deq + n_last_deq >= size)
805 if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY)
807 if (!f->has_deq_ntf && svm_fifo_is_empty (f))
813 #endif /* __included_ssvm_fifo_h__ */
816 * fd.io coding-style-patch-verification: ON
819 * eval: (c-set-style "gnu")