2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <svm/svm_fifo.h>
17 #include <vppinfra/cpu.h>
20 position_lt (svm_fifo_t * f, u32 a, u32 b)
22 return (ooo_segment_distance_from_tail (f, a)
23 < ooo_segment_distance_from_tail (f, b));
27 position_leq (svm_fifo_t * f, u32 a, u32 b)
29 return (ooo_segment_distance_from_tail (f, a)
30 <= ooo_segment_distance_from_tail (f, b));
34 position_gt (svm_fifo_t * f, u32 a, u32 b)
36 return (ooo_segment_distance_from_tail (f, a)
37 > ooo_segment_distance_from_tail (f, b));
41 position_diff (svm_fifo_t * f, u32 posa, u32 posb)
43 return ooo_segment_distance_from_tail (f, posa)
44 - ooo_segment_distance_from_tail (f, posb);
48 ooo_segment_end_pos (svm_fifo_t * f, ooo_segment_t * s)
50 return (s->start + s->length) % f->nitems;
53 #ifndef CLIB_MARCH_VARIANT
56 format_ooo_segment (u8 * s, va_list * args)
58 svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
59 ooo_segment_t *seg = va_arg (*args, ooo_segment_t *);
60 u32 normalized_start = (seg->start + f->nitems - f->tail) % f->nitems;
61 s = format (s, "[%u, %u], len %u, next %d, prev %d", normalized_start,
62 (normalized_start + seg->length) % f->nitems, seg->length,
63 seg->next, seg->prev);
68 svm_fifo_dump_trace (u8 * s, svm_fifo_t * f)
71 svm_fifo_trace_elem_t *seg = 0;
76 vec_foreach (seg, f->trace)
78 s = format (s, "{%u, %u, %u}, ", seg->offset, seg->len, seg->action);
92 svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose)
96 svm_fifo_trace_elem_t *trace;
98 svm_fifo_t *dummy_fifo;
105 trace_len = vec_len (trace);
111 dummy_fifo = svm_fifo_create (f->nitems);
112 clib_memset (f->data, 0xFF, f->nitems);
114 vec_validate (data, f->nitems);
115 for (i = 0; i < vec_len (data); i++)
118 for (i = 0; i < trace_len; i++)
120 offset = trace[i].offset;
121 if (trace[i].action == 1)
124 s = format (s, "adding [%u, %u]:", trace[i].offset,
126 trace[i].len) % dummy_fifo->nitems);
127 svm_fifo_enqueue_with_offset (dummy_fifo, trace[i].offset,
128 trace[i].len, &data[offset]);
130 else if (trace[i].action == 2)
133 s = format (s, "adding [%u, %u]:", 0, trace[i].len);
134 svm_fifo_enqueue_nowait (dummy_fifo, trace[i].len, &data[offset]);
139 s = format (s, "read: %u", trace[i].len);
140 svm_fifo_dequeue_drop (dummy_fifo, trace[i].len);
143 s = format (s, "%U", format_svm_fifo, dummy_fifo, 1);
146 s = format (s, "result: %U", format_svm_fifo, dummy_fifo, 1);
152 format_ooo_list (u8 * s, va_list * args)
154 svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
155 u32 indent = va_arg (*args, u32);
156 u32 ooo_segment_index = f->ooos_list_head;
159 while (ooo_segment_index != OOO_SEGMENT_INVALID_INDEX)
161 seg = pool_elt_at_index (f->ooo_segments, ooo_segment_index);
162 s = format (s, "%U%U\n", format_white_space, indent, format_ooo_segment,
164 ooo_segment_index = seg->next;
171 format_svm_fifo (u8 * s, va_list * args)
173 svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
174 int verbose = va_arg (*args, int);
180 indent = format_get_indent (s);
181 s = format (s, "cursize %u nitems %u has_event %d\n",
182 f->cursize, f->nitems, f->has_event);
183 s = format (s, "%Uhead %d tail %d segment manager %u\n", format_white_space,
184 indent, f->head, f->tail, f->segment_manager);
187 s = format (s, "%Uvpp session %d thread %d app session %d thread %d\n",
188 format_white_space, indent, f->master_session_index,
189 f->master_thread_index, f->client_session_index,
190 f->client_thread_index);
194 s = format (s, "%Uooo pool %d active elts newest %u\n",
195 format_white_space, indent, pool_elts (f->ooo_segments),
197 if (svm_fifo_has_ooo_data (f))
198 s = format (s, " %U", format_ooo_list, f, indent, verbose);
203 /** create an svm fifo, in the current heap. Fails vs blow up the process */
205 svm_fifo_create (u32 data_size_in_bytes)
208 u32 rounded_data_size;
210 /* always round fifo data size to the next highest power-of-two */
211 rounded_data_size = (1 << (max_log2 (data_size_in_bytes)));
212 f = clib_mem_alloc_aligned_or_null (sizeof (*f) + rounded_data_size,
213 CLIB_CACHE_LINE_BYTES);
217 clib_memset (f, 0, sizeof (*f));
218 f->nitems = data_size_in_bytes;
219 f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX;
220 f->ct_session_index = SVM_FIFO_INVALID_SESSION_INDEX;
226 svm_fifo_free (svm_fifo_t * f)
228 ASSERT (f->refcnt > 0);
230 if (--f->refcnt == 0)
232 pool_free (f->ooo_segments);
238 always_inline ooo_segment_t *
239 ooo_segment_new (svm_fifo_t * f, u32 start, u32 length)
243 pool_get (f->ooo_segments, s);
248 s->prev = s->next = OOO_SEGMENT_INVALID_INDEX;
254 ooo_segment_del (svm_fifo_t * f, u32 index)
256 ooo_segment_t *cur, *prev = 0, *next = 0;
257 cur = pool_elt_at_index (f->ooo_segments, index);
259 if (cur->next != OOO_SEGMENT_INVALID_INDEX)
261 next = pool_elt_at_index (f->ooo_segments, cur->next);
262 next->prev = cur->prev;
265 if (cur->prev != OOO_SEGMENT_INVALID_INDEX)
267 prev = pool_elt_at_index (f->ooo_segments, cur->prev);
268 prev->next = cur->next;
272 f->ooos_list_head = cur->next;
275 pool_put (f->ooo_segments, cur);
279 * Add segment to fifo's out-of-order segment list. Takes care of merging
280 * adjacent segments and removing overlapping ones.
283 ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
285 ooo_segment_t *s, *new_s, *prev, *next, *it;
286 u32 new_index, s_end_pos, s_index;
287 u32 normalized_position, normalized_end_position;
289 ASSERT (offset + length <= ooo_segment_distance_from_tail (f, f->head));
290 normalized_position = (f->tail + offset) % f->nitems;
291 normalized_end_position = (f->tail + offset + length) % f->nitems;
293 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
295 if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX)
297 s = ooo_segment_new (f, normalized_position, length);
298 f->ooos_list_head = s - f->ooo_segments;
299 f->ooos_newest = f->ooos_list_head;
303 /* Find first segment that starts after new segment */
304 s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
305 while (s->next != OOO_SEGMENT_INVALID_INDEX
306 && position_lt (f, s->start, normalized_position))
307 s = pool_elt_at_index (f->ooo_segments, s->next);
309 /* If we have a previous and we overlap it, use it as starting point */
310 prev = ooo_segment_get_prev (f, s);
312 && position_leq (f, normalized_position, ooo_segment_end_pos (f, prev)))
315 s_end_pos = ooo_segment_end_pos (f, s);
317 /* Since we have previous, normalized start position cannot be smaller
318 * than prev->start. Check tail */
319 ASSERT (position_lt (f, s->start, normalized_position));
323 s_index = s - f->ooo_segments;
324 s_end_pos = ooo_segment_end_pos (f, s);
326 /* No overlap, add before current segment */
327 if (position_lt (f, normalized_end_position, s->start))
329 new_s = ooo_segment_new (f, normalized_position, length);
330 new_index = new_s - f->ooo_segments;
332 /* Pool might've moved, get segment again */
333 s = pool_elt_at_index (f->ooo_segments, s_index);
334 if (s->prev != OOO_SEGMENT_INVALID_INDEX)
336 new_s->prev = s->prev;
337 prev = pool_elt_at_index (f->ooo_segments, new_s->prev);
338 prev->next = new_index;
343 f->ooos_list_head = new_index;
346 new_s->next = s_index;
348 f->ooos_newest = new_index;
351 /* No overlap, add after current segment */
352 else if (position_gt (f, normalized_position, s_end_pos))
354 new_s = ooo_segment_new (f, normalized_position, length);
355 new_index = new_s - f->ooo_segments;
357 /* Pool might've moved, get segment again */
358 s = pool_elt_at_index (f->ooo_segments, s_index);
360 /* Needs to be last */
361 ASSERT (s->next == OOO_SEGMENT_INVALID_INDEX);
363 new_s->prev = s_index;
365 f->ooos_newest = new_index;
375 if (position_lt (f, normalized_position, s->start))
377 s->start = normalized_position;
378 s->length = position_diff (f, s_end_pos, s->start);
379 f->ooos_newest = s - f->ooo_segments;
384 /* Overlapping tail */
385 if (position_gt (f, normalized_end_position, s_end_pos))
387 s->length = position_diff (f, normalized_end_position, s->start);
389 /* Remove the completely overlapped segments in the tail */
390 it = ooo_segment_next (f, s);
391 while (it && position_leq (f, ooo_segment_end_pos (f, it),
392 normalized_end_position))
394 next = ooo_segment_next (f, it);
395 ooo_segment_del (f, it - f->ooo_segments);
399 /* If partial overlap with last, merge */
400 if (it && position_leq (f, it->start, normalized_end_position))
402 s->length = position_diff (f, ooo_segment_end_pos (f, it),
404 ooo_segment_del (f, it - f->ooo_segments);
406 f->ooos_newest = s - f->ooo_segments;
411 * Removes segments that can now be enqueued because the fifo's tail has
412 * advanced. Returns the number of bytes added to tail.
415 ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued)
418 u32 index, bytes = 0;
421 s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
422 diff = ooo_segment_distance_to_tail (f, s->start);
424 ASSERT (diff != n_bytes_enqueued);
426 if (diff > n_bytes_enqueued)
429 /* If last tail update overlaps one/multiple ooo segments, remove them */
430 while (0 <= diff && diff < n_bytes_enqueued)
432 index = s - f->ooo_segments;
434 /* Segment end is beyond the tail. Advance tail and remove segment */
435 if (s->length > diff)
437 bytes = s->length - diff;
439 f->tail %= f->nitems;
440 ooo_segment_del (f, index);
444 /* If we have next go on */
445 if (s->next != OOO_SEGMENT_INVALID_INDEX)
447 s = pool_elt_at_index (f->ooo_segments, s->next);
448 diff = ooo_segment_distance_to_tail (f, s->start);
449 ooo_segment_del (f, index);
454 ooo_segment_del (f, index);
459 ASSERT (bytes <= f->nitems);
463 CLIB_MARCH_FN (svm_fifo_enqueue_nowait, int, svm_fifo_t * f, u32 max_bytes,
464 const u8 * copy_from_here)
466 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
469 /* read cursize, which can only increase while we're working */
470 cursize = svm_fifo_max_dequeue (f);
471 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
473 if (PREDICT_FALSE (cursize == f->nitems))
474 return SVM_FIFO_FULL;
478 /* Number of bytes we're going to copy */
479 total_copy_bytes = (nitems - cursize) < max_bytes ?
480 (nitems - cursize) : max_bytes;
482 if (PREDICT_TRUE (copy_from_here != 0))
484 /* Number of bytes in first copy segment */
485 first_copy_bytes = ((nitems - f->tail) < total_copy_bytes)
486 ? (nitems - f->tail) : total_copy_bytes;
488 clib_memcpy_fast (&f->data[f->tail], copy_from_here, first_copy_bytes);
489 f->tail += first_copy_bytes;
490 f->tail = (f->tail == nitems) ? 0 : f->tail;
492 /* Number of bytes in second copy segment, if any */
493 second_copy_bytes = total_copy_bytes - first_copy_bytes;
494 if (second_copy_bytes)
496 clib_memcpy_fast (&f->data[f->tail],
497 copy_from_here + first_copy_bytes,
499 f->tail += second_copy_bytes;
500 f->tail = (f->tail == nitems) ? 0 : f->tail;
507 /* Account for a zero-copy enqueue done elsewhere */
508 ASSERT (max_bytes <= (nitems - cursize));
509 f->tail += max_bytes;
510 f->tail = f->tail % nitems;
511 total_copy_bytes = max_bytes;
514 svm_fifo_trace_add (f, f->head, total_copy_bytes, 2);
516 /* Any out-of-order segments to collect? */
517 if (PREDICT_FALSE (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX))
518 total_copy_bytes += ooo_segment_try_collect (f, total_copy_bytes);
520 /* Atomically increase the queue length */
521 ASSERT (cursize + total_copy_bytes <= nitems);
522 clib_atomic_fetch_add (&f->cursize, total_copy_bytes);
524 return (total_copy_bytes);
527 #ifndef CLIB_MARCH_VARIANT
529 svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
530 const u8 * copy_from_here)
532 return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_nowait) (f, max_bytes,
538 * Enqueue a future segment.
540 * Two choices: either copies the entire segment, or copies nothing
541 * Returns 0 of the entire segment was copied
542 * Returns -1 if none of the segment was copied due to lack of space
544 CLIB_MARCH_FN (svm_fifo_enqueue_with_offset, int, svm_fifo_t * f,
545 u32 offset, u32 required_bytes, u8 * copy_from_here)
547 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
548 u32 cursize, nitems, normalized_offset;
550 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
552 /* read cursize, which can only increase while we're working */
553 cursize = svm_fifo_max_dequeue (f);
556 ASSERT (required_bytes < nitems);
558 normalized_offset = (f->tail + offset) % nitems;
560 /* Will this request fit? */
561 if ((required_bytes + offset) > (nitems - cursize))
564 svm_fifo_trace_add (f, offset, required_bytes, 1);
566 ooo_segment_add (f, offset, required_bytes);
568 /* Number of bytes we're going to copy */
569 total_copy_bytes = required_bytes;
571 /* Number of bytes in first copy segment */
572 first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes)
573 ? (nitems - normalized_offset) : total_copy_bytes;
575 clib_memcpy_fast (&f->data[normalized_offset], copy_from_here,
578 /* Number of bytes in second copy segment, if any */
579 second_copy_bytes = total_copy_bytes - first_copy_bytes;
580 if (second_copy_bytes)
582 normalized_offset += first_copy_bytes;
583 normalized_offset %= nitems;
585 ASSERT (normalized_offset == 0);
587 clib_memcpy_fast (&f->data[normalized_offset],
588 copy_from_here + first_copy_bytes, second_copy_bytes);
594 #ifndef CLIB_MARCH_VARIANT
597 svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 required_bytes,
600 return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_with_offset) (f, offset,
606 svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len)
609 first_chunk = f->nitems - f->head;
610 ASSERT (len <= f->nitems);
611 if (len <= first_chunk)
612 clib_memcpy_fast (&f->data[f->head], data, len);
615 clib_memcpy_fast (&f->data[f->head], data, first_chunk);
616 clib_memcpy_fast (&f->data[0], data + first_chunk, len - first_chunk);
621 CLIB_MARCH_FN (svm_fifo_dequeue_nowait, int, svm_fifo_t * f, u32 max_bytes,
624 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
627 /* read cursize, which can only increase while we're working */
628 cursize = svm_fifo_max_dequeue (f);
629 if (PREDICT_FALSE (cursize == 0))
630 return -2; /* nothing in the fifo */
634 /* Number of bytes we're going to copy */
635 total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes;
637 if (PREDICT_TRUE (copy_here != 0))
639 /* Number of bytes in first copy segment */
640 first_copy_bytes = ((nitems - f->head) < total_copy_bytes)
641 ? (nitems - f->head) : total_copy_bytes;
642 clib_memcpy_fast (copy_here, &f->data[f->head], first_copy_bytes);
643 f->head += first_copy_bytes;
644 f->head = (f->head == nitems) ? 0 : f->head;
646 /* Number of bytes in second copy segment, if any */
647 second_copy_bytes = total_copy_bytes - first_copy_bytes;
648 if (second_copy_bytes)
650 clib_memcpy_fast (copy_here + first_copy_bytes,
651 &f->data[f->head], second_copy_bytes);
652 f->head += second_copy_bytes;
653 f->head = (f->head == nitems) ? 0 : f->head;
659 /* Account for a zero-copy dequeue done elsewhere */
660 ASSERT (max_bytes <= cursize);
661 f->head += max_bytes;
662 f->head = f->head % nitems;
663 cursize -= max_bytes;
664 total_copy_bytes = max_bytes;
667 ASSERT (f->head <= nitems);
668 ASSERT (cursize >= total_copy_bytes);
669 clib_atomic_fetch_sub (&f->cursize, total_copy_bytes);
671 return (total_copy_bytes);
674 #ifndef CLIB_MARCH_VARIANT
677 svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
679 return CLIB_MARCH_FN_SELECT (svm_fifo_dequeue_nowait) (f, max_bytes,
684 CLIB_MARCH_FN (svm_fifo_peek, int, svm_fifo_t * f, u32 relative_offset,
685 u32 max_bytes, u8 * copy_here)
687 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
688 u32 cursize, nitems, real_head;
690 /* read cursize, which can only increase while we're working */
691 cursize = svm_fifo_max_dequeue (f);
692 if (PREDICT_FALSE (cursize < relative_offset))
693 return -2; /* nothing in the fifo */
696 real_head = f->head + relative_offset;
697 real_head = real_head >= nitems ? real_head - nitems : real_head;
699 /* Number of bytes we're going to copy */
700 total_copy_bytes = (cursize - relative_offset < max_bytes) ?
701 cursize - relative_offset : max_bytes;
703 if (PREDICT_TRUE (copy_here != 0))
705 /* Number of bytes in first copy segment */
707 ((nitems - real_head) < total_copy_bytes) ?
708 (nitems - real_head) : total_copy_bytes;
709 clib_memcpy_fast (copy_here, &f->data[real_head], first_copy_bytes);
711 /* Number of bytes in second copy segment, if any */
712 second_copy_bytes = total_copy_bytes - first_copy_bytes;
713 if (second_copy_bytes)
715 clib_memcpy_fast (copy_here + first_copy_bytes, &f->data[0],
719 return total_copy_bytes;
722 #ifndef CLIB_MARCH_VARIANT
725 svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
728 return CLIB_MARCH_FN_SELECT (svm_fifo_peek) (f, relative_offset, max_bytes,
733 svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes)
735 u32 total_drop_bytes, first_drop_bytes, second_drop_bytes;
738 /* read cursize, which can only increase while we're working */
739 cursize = svm_fifo_max_dequeue (f);
740 if (PREDICT_FALSE (cursize == 0))
741 return -2; /* nothing in the fifo */
745 /* Number of bytes we're going to drop */
746 total_drop_bytes = (cursize < max_bytes) ? cursize : max_bytes;
748 svm_fifo_trace_add (f, f->tail, total_drop_bytes, 3);
750 /* Number of bytes in first copy segment */
752 ((nitems - f->head) < total_drop_bytes) ?
753 (nitems - f->head) : total_drop_bytes;
754 f->head += first_drop_bytes;
755 f->head = (f->head == nitems) ? 0 : f->head;
757 /* Number of bytes in second drop segment, if any */
758 second_drop_bytes = total_drop_bytes - first_drop_bytes;
759 if (second_drop_bytes)
761 f->head += second_drop_bytes;
762 f->head = (f->head == nitems) ? 0 : f->head;
765 ASSERT (f->head <= nitems);
766 ASSERT (cursize >= total_drop_bytes);
767 clib_atomic_fetch_sub (&f->cursize, total_drop_bytes);
769 return total_drop_bytes;
773 svm_fifo_dequeue_drop_all (svm_fifo_t * f)
776 clib_atomic_fetch_sub (&f->cursize, f->cursize);
780 svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs)
784 /* read cursize, which can only increase while we're working */
785 cursize = svm_fifo_max_dequeue (f);
786 if (PREDICT_FALSE (cursize == 0))
791 fs[0].len = ((nitems - f->head) < cursize) ? (nitems - f->head) : cursize;
792 fs[0].data = f->data + f->head;
794 if (fs[0].len < cursize)
796 fs[1].len = cursize - fs[0].len;
797 fs[1].data = f->data;
808 svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs)
810 u32 total_drop_bytes;
812 ASSERT (fs[0].data == f->data + f->head);
816 total_drop_bytes = fs[0].len + fs[1].len;
820 f->head = (f->head + fs[0].len) % f->nitems;
821 total_drop_bytes = fs[0].len;
823 clib_atomic_fetch_sub (&f->cursize, total_drop_bytes);
827 svm_fifo_number_ooo_segments (svm_fifo_t * f)
829 return pool_elts (f->ooo_segments);
833 svm_fifo_first_ooo_segment (svm_fifo_t * f)
835 return pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
839 * Set fifo pointers to requested offset
842 svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
844 f->head = f->tail = pointer % f->nitems;
849 * fd.io coding-style-patch-verification: ON
852 * eval: (c-set-style "gnu")