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;
221 f->segment_index = SVM_FIFO_INVALID_INDEX;
227 svm_fifo_free (svm_fifo_t * f)
229 ASSERT (f->refcnt > 0);
231 if (--f->refcnt == 0)
233 pool_free (f->ooo_segments);
239 always_inline ooo_segment_t *
240 ooo_segment_new (svm_fifo_t * f, u32 start, u32 length)
244 pool_get (f->ooo_segments, s);
249 s->prev = s->next = OOO_SEGMENT_INVALID_INDEX;
255 ooo_segment_del (svm_fifo_t * f, u32 index)
257 ooo_segment_t *cur, *prev = 0, *next = 0;
258 cur = pool_elt_at_index (f->ooo_segments, index);
260 if (cur->next != OOO_SEGMENT_INVALID_INDEX)
262 next = pool_elt_at_index (f->ooo_segments, cur->next);
263 next->prev = cur->prev;
266 if (cur->prev != OOO_SEGMENT_INVALID_INDEX)
268 prev = pool_elt_at_index (f->ooo_segments, cur->prev);
269 prev->next = cur->next;
273 f->ooos_list_head = cur->next;
276 pool_put (f->ooo_segments, cur);
280 * Add segment to fifo's out-of-order segment list. Takes care of merging
281 * adjacent segments and removing overlapping ones.
284 ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
286 ooo_segment_t *s, *new_s, *prev, *next, *it;
287 u32 new_index, s_end_pos, s_index;
288 u32 normalized_position, normalized_end_position;
290 ASSERT (offset + length <= ooo_segment_distance_from_tail (f, f->head));
291 normalized_position = (f->tail + offset) % f->nitems;
292 normalized_end_position = (f->tail + offset + length) % f->nitems;
294 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
296 if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX)
298 s = ooo_segment_new (f, normalized_position, length);
299 f->ooos_list_head = s - f->ooo_segments;
300 f->ooos_newest = f->ooos_list_head;
304 /* Find first segment that starts after new segment */
305 s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
306 while (s->next != OOO_SEGMENT_INVALID_INDEX
307 && position_lt (f, s->start, normalized_position))
308 s = pool_elt_at_index (f->ooo_segments, s->next);
310 /* If we have a previous and we overlap it, use it as starting point */
311 prev = ooo_segment_get_prev (f, s);
313 && position_leq (f, normalized_position, ooo_segment_end_pos (f, prev)))
316 s_end_pos = ooo_segment_end_pos (f, s);
318 /* Since we have previous, normalized start position cannot be smaller
319 * than prev->start. Check tail */
320 ASSERT (position_lt (f, s->start, normalized_position));
324 s_index = s - f->ooo_segments;
325 s_end_pos = ooo_segment_end_pos (f, s);
327 /* No overlap, add before current segment */
328 if (position_lt (f, normalized_end_position, s->start))
330 new_s = ooo_segment_new (f, normalized_position, length);
331 new_index = new_s - f->ooo_segments;
333 /* Pool might've moved, get segment again */
334 s = pool_elt_at_index (f->ooo_segments, s_index);
335 if (s->prev != OOO_SEGMENT_INVALID_INDEX)
337 new_s->prev = s->prev;
338 prev = pool_elt_at_index (f->ooo_segments, new_s->prev);
339 prev->next = new_index;
344 f->ooos_list_head = new_index;
347 new_s->next = s_index;
349 f->ooos_newest = new_index;
352 /* No overlap, add after current segment */
353 else if (position_gt (f, normalized_position, s_end_pos))
355 new_s = ooo_segment_new (f, normalized_position, length);
356 new_index = new_s - f->ooo_segments;
358 /* Pool might've moved, get segment again */
359 s = pool_elt_at_index (f->ooo_segments, s_index);
361 /* Needs to be last */
362 ASSERT (s->next == OOO_SEGMENT_INVALID_INDEX);
364 new_s->prev = s_index;
366 f->ooos_newest = new_index;
376 if (position_lt (f, normalized_position, s->start))
378 s->start = normalized_position;
379 s->length = position_diff (f, s_end_pos, s->start);
380 f->ooos_newest = s - f->ooo_segments;
385 /* Overlapping tail */
386 if (position_gt (f, normalized_end_position, s_end_pos))
388 s->length = position_diff (f, normalized_end_position, s->start);
390 /* Remove the completely overlapped segments in the tail */
391 it = ooo_segment_next (f, s);
392 while (it && position_leq (f, ooo_segment_end_pos (f, it),
393 normalized_end_position))
395 next = ooo_segment_next (f, it);
396 ooo_segment_del (f, it - f->ooo_segments);
400 /* If partial overlap with last, merge */
401 if (it && position_leq (f, it->start, normalized_end_position))
403 s->length = position_diff (f, ooo_segment_end_pos (f, it),
405 ooo_segment_del (f, it - f->ooo_segments);
407 f->ooos_newest = s - f->ooo_segments;
412 * Removes segments that can now be enqueued because the fifo's tail has
413 * advanced. Returns the number of bytes added to tail.
416 ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued)
419 u32 index, bytes = 0;
422 s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
423 diff = ooo_segment_distance_to_tail (f, s->start);
425 ASSERT (diff != n_bytes_enqueued);
427 if (diff > n_bytes_enqueued)
430 /* If last tail update overlaps one/multiple ooo segments, remove them */
431 while (0 <= diff && diff < n_bytes_enqueued)
433 index = s - f->ooo_segments;
435 /* Segment end is beyond the tail. Advance tail and remove segment */
436 if (s->length > diff)
438 bytes = s->length - diff;
440 f->tail %= f->nitems;
441 ooo_segment_del (f, index);
445 /* If we have next go on */
446 if (s->next != OOO_SEGMENT_INVALID_INDEX)
448 s = pool_elt_at_index (f->ooo_segments, s->next);
449 diff = ooo_segment_distance_to_tail (f, s->start);
450 ooo_segment_del (f, index);
455 ooo_segment_del (f, index);
460 ASSERT (bytes <= f->nitems);
464 CLIB_MARCH_FN (svm_fifo_enqueue_nowait, int, svm_fifo_t * f, u32 max_bytes,
465 const u8 * copy_from_here)
467 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
470 /* read cursize, which can only increase while we're working */
471 cursize = svm_fifo_max_dequeue (f);
472 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
474 if (PREDICT_FALSE (cursize == f->nitems))
475 return SVM_FIFO_FULL;
479 /* Number of bytes we're going to copy */
480 total_copy_bytes = (nitems - cursize) < max_bytes ?
481 (nitems - cursize) : max_bytes;
483 if (PREDICT_TRUE (copy_from_here != 0))
485 /* Number of bytes in first copy segment */
486 first_copy_bytes = ((nitems - f->tail) < total_copy_bytes)
487 ? (nitems - f->tail) : total_copy_bytes;
489 clib_memcpy_fast (&f->data[f->tail], copy_from_here, first_copy_bytes);
490 f->tail += first_copy_bytes;
491 f->tail = (f->tail == nitems) ? 0 : f->tail;
493 /* Number of bytes in second copy segment, if any */
494 second_copy_bytes = total_copy_bytes - first_copy_bytes;
495 if (second_copy_bytes)
497 clib_memcpy_fast (&f->data[f->tail],
498 copy_from_here + first_copy_bytes,
500 f->tail += second_copy_bytes;
501 f->tail = (f->tail == nitems) ? 0 : f->tail;
508 /* Account for a zero-copy enqueue done elsewhere */
509 ASSERT (max_bytes <= (nitems - cursize));
510 f->tail += max_bytes;
511 f->tail = f->tail % nitems;
512 total_copy_bytes = max_bytes;
515 svm_fifo_trace_add (f, f->head, total_copy_bytes, 2);
517 /* Any out-of-order segments to collect? */
518 if (PREDICT_FALSE (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX))
519 total_copy_bytes += ooo_segment_try_collect (f, total_copy_bytes);
521 /* Atomically increase the queue length */
522 ASSERT (cursize + total_copy_bytes <= nitems);
523 clib_atomic_fetch_add_rel (&f->cursize, total_copy_bytes);
525 return (total_copy_bytes);
528 #ifndef CLIB_MARCH_VARIANT
530 svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
531 const u8 * copy_from_here)
533 return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_nowait) (f, max_bytes,
539 * Enqueue a future segment.
541 * Two choices: either copies the entire segment, or copies nothing
542 * Returns 0 of the entire segment was copied
543 * Returns -1 if none of the segment was copied due to lack of space
545 CLIB_MARCH_FN (svm_fifo_enqueue_with_offset, int, svm_fifo_t * f,
546 u32 offset, u32 required_bytes, u8 * copy_from_here)
548 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
549 u32 cursize, nitems, normalized_offset;
551 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
553 /* read cursize, which can only increase while we're working */
554 cursize = svm_fifo_max_dequeue (f);
557 ASSERT (required_bytes < nitems);
559 normalized_offset = (f->tail + offset) % nitems;
561 /* Will this request fit? */
562 if ((required_bytes + offset) > (nitems - cursize))
565 svm_fifo_trace_add (f, offset, required_bytes, 1);
567 ooo_segment_add (f, offset, required_bytes);
569 /* Number of bytes we're going to copy */
570 total_copy_bytes = required_bytes;
572 /* Number of bytes in first copy segment */
573 first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes)
574 ? (nitems - normalized_offset) : total_copy_bytes;
576 clib_memcpy_fast (&f->data[normalized_offset], copy_from_here,
579 /* Number of bytes in second copy segment, if any */
580 second_copy_bytes = total_copy_bytes - first_copy_bytes;
581 if (second_copy_bytes)
583 normalized_offset += first_copy_bytes;
584 normalized_offset %= nitems;
586 ASSERT (normalized_offset == 0);
588 clib_memcpy_fast (&f->data[normalized_offset],
589 copy_from_here + first_copy_bytes, second_copy_bytes);
595 #ifndef CLIB_MARCH_VARIANT
598 svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 required_bytes,
601 return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_with_offset) (f, offset,
607 svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len)
610 first_chunk = f->nitems - f->head;
611 ASSERT (len <= f->nitems);
612 if (len <= first_chunk)
613 clib_memcpy_fast (&f->data[f->head], data, len);
616 clib_memcpy_fast (&f->data[f->head], data, first_chunk);
617 clib_memcpy_fast (&f->data[0], data + first_chunk, len - first_chunk);
622 CLIB_MARCH_FN (svm_fifo_dequeue_nowait, int, svm_fifo_t * f, u32 max_bytes,
625 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
628 /* read cursize, which can only increase while we're working */
629 cursize = svm_fifo_max_dequeue (f);
630 if (PREDICT_FALSE (cursize == 0))
631 return -2; /* nothing in the fifo */
635 /* Number of bytes we're going to copy */
636 total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes;
638 if (PREDICT_TRUE (copy_here != 0))
640 /* Number of bytes in first copy segment */
641 first_copy_bytes = ((nitems - f->head) < total_copy_bytes)
642 ? (nitems - f->head) : total_copy_bytes;
643 clib_memcpy_fast (copy_here, &f->data[f->head], first_copy_bytes);
644 f->head += first_copy_bytes;
645 f->head = (f->head == nitems) ? 0 : f->head;
647 /* Number of bytes in second copy segment, if any */
648 second_copy_bytes = total_copy_bytes - first_copy_bytes;
649 if (second_copy_bytes)
651 clib_memcpy_fast (copy_here + first_copy_bytes,
652 &f->data[f->head], second_copy_bytes);
653 f->head += second_copy_bytes;
654 f->head = (f->head == nitems) ? 0 : f->head;
660 /* Account for a zero-copy dequeue done elsewhere */
661 ASSERT (max_bytes <= cursize);
662 f->head += max_bytes;
663 f->head = f->head % nitems;
664 cursize -= max_bytes;
665 total_copy_bytes = max_bytes;
668 ASSERT (f->head <= nitems);
669 ASSERT (cursize >= total_copy_bytes);
670 clib_atomic_fetch_sub_rel (&f->cursize, total_copy_bytes);
672 return (total_copy_bytes);
675 #ifndef CLIB_MARCH_VARIANT
678 svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
680 return CLIB_MARCH_FN_SELECT (svm_fifo_dequeue_nowait) (f, max_bytes,
685 CLIB_MARCH_FN (svm_fifo_peek, int, svm_fifo_t * f, u32 relative_offset,
686 u32 max_bytes, u8 * copy_here)
688 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
689 u32 cursize, nitems, real_head;
691 /* read cursize, which can only increase while we're working */
692 cursize = svm_fifo_max_dequeue (f);
693 if (PREDICT_FALSE (cursize < relative_offset))
694 return -2; /* nothing in the fifo */
697 real_head = f->head + relative_offset;
698 real_head = real_head >= nitems ? real_head - nitems : real_head;
700 /* Number of bytes we're going to copy */
701 total_copy_bytes = (cursize - relative_offset < max_bytes) ?
702 cursize - relative_offset : max_bytes;
704 if (PREDICT_TRUE (copy_here != 0))
706 /* Number of bytes in first copy segment */
708 ((nitems - real_head) < total_copy_bytes) ?
709 (nitems - real_head) : total_copy_bytes;
710 clib_memcpy_fast (copy_here, &f->data[real_head], first_copy_bytes);
712 /* Number of bytes in second copy segment, if any */
713 second_copy_bytes = total_copy_bytes - first_copy_bytes;
714 if (second_copy_bytes)
716 clib_memcpy_fast (copy_here + first_copy_bytes, &f->data[0],
720 return total_copy_bytes;
723 #ifndef CLIB_MARCH_VARIANT
726 svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
729 return CLIB_MARCH_FN_SELECT (svm_fifo_peek) (f, relative_offset, max_bytes,
734 svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes)
736 u32 total_drop_bytes, first_drop_bytes, second_drop_bytes;
739 /* read cursize, which can only increase while we're working */
740 cursize = svm_fifo_max_dequeue (f);
741 if (PREDICT_FALSE (cursize == 0))
742 return -2; /* nothing in the fifo */
746 /* Number of bytes we're going to drop */
747 total_drop_bytes = (cursize < max_bytes) ? cursize : max_bytes;
749 svm_fifo_trace_add (f, f->tail, total_drop_bytes, 3);
751 /* Number of bytes in first copy segment */
753 ((nitems - f->head) < total_drop_bytes) ?
754 (nitems - f->head) : total_drop_bytes;
755 f->head += first_drop_bytes;
756 f->head = (f->head == nitems) ? 0 : f->head;
758 /* Number of bytes in second drop segment, if any */
759 second_drop_bytes = total_drop_bytes - first_drop_bytes;
760 if (second_drop_bytes)
762 f->head += second_drop_bytes;
763 f->head = (f->head == nitems) ? 0 : f->head;
766 ASSERT (f->head <= nitems);
767 ASSERT (cursize >= total_drop_bytes);
768 clib_atomic_fetch_sub_rel (&f->cursize, total_drop_bytes);
770 return total_drop_bytes;
774 svm_fifo_dequeue_drop_all (svm_fifo_t * f)
777 clib_atomic_fetch_sub_rel (&f->cursize, f->cursize);
781 svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs)
785 /* read cursize, which can only increase while we're working */
786 cursize = svm_fifo_max_dequeue (f);
787 if (PREDICT_FALSE (cursize == 0))
792 fs[0].len = ((nitems - f->head) < cursize) ? (nitems - f->head) : cursize;
793 fs[0].data = f->data + f->head;
795 if (fs[0].len < cursize)
797 fs[1].len = cursize - fs[0].len;
798 fs[1].data = f->data;
809 svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs)
811 u32 total_drop_bytes;
813 ASSERT (fs[0].data == f->data + f->head);
817 total_drop_bytes = fs[0].len + fs[1].len;
821 f->head = (f->head + fs[0].len) % f->nitems;
822 total_drop_bytes = fs[0].len;
824 clib_atomic_fetch_sub_rel (&f->cursize, total_drop_bytes);
828 svm_fifo_number_ooo_segments (svm_fifo_t * f)
830 return pool_elts (f->ooo_segments);
834 svm_fifo_first_ooo_segment (svm_fifo_t * f)
836 return pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
840 * Set fifo pointers to requested offset
843 svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
845 f->head = f->tail = pointer % f->nitems;
850 * fd.io coding-style-patch-verification: ON
853 * eval: (c-set-style "gnu")