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;
54 format_ooo_segment (u8 * s, va_list * args)
56 ooo_segment_t *seg = va_arg (*args, ooo_segment_t *);
58 s = format (s, "pos %u, len %u, next %d, prev %d",
59 seg->start, seg->length, seg->next, seg->prev);
64 svm_fifo_dump_trace (u8 * s, svm_fifo_t * f)
67 svm_fifo_trace_elem_t *seg = 0;
72 vec_foreach (seg, f->trace)
74 s = format (s, "{%u, %u, %u}, ", seg->offset, seg->len, seg->action);
88 svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose)
92 svm_fifo_trace_elem_t *trace;
94 svm_fifo_t *dummy_fifo;
101 trace_len = vec_len (trace);
107 dummy_fifo = svm_fifo_create (f->nitems);
108 memset (f->data, 0xFF, f->nitems);
110 vec_validate (data, f->nitems);
111 for (i = 0; i < vec_len (data); i++)
114 for (i = 0; i < trace_len; i++)
116 offset = trace[i].offset;
117 if (trace[i].action == 1)
120 s = format (s, "adding [%u, %u]:", trace[i].offset,
122 trace[i].len) % dummy_fifo->nitems);
123 svm_fifo_enqueue_with_offset (dummy_fifo, trace[i].offset,
124 trace[i].len, &data[offset]);
126 else if (trace[i].action == 2)
129 s = format (s, "adding [%u, %u]:", 0, trace[i].len);
130 svm_fifo_enqueue_nowait (dummy_fifo, trace[i].len, &data[offset]);
135 s = format (s, "read: %u", trace[i].len);
136 svm_fifo_dequeue_drop (dummy_fifo, trace[i].len);
139 s = format (s, "%U", format_svm_fifo, dummy_fifo, 1);
142 s = format (s, "result: %U", format_svm_fifo, dummy_fifo, 1);
148 format_ooo_list (u8 * s, va_list * args)
150 svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
151 u32 ooo_segment_index = f->ooos_list_head;
154 while (ooo_segment_index != OOO_SEGMENT_INVALID_INDEX)
156 seg = pool_elt_at_index (f->ooo_segments, ooo_segment_index);
157 s = format (s, " %U\n", format_ooo_segment, seg);
158 ooo_segment_index = seg->next;
165 format_svm_fifo (u8 * s, va_list * args)
167 svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
168 int verbose = va_arg (*args, int);
170 s = format (s, "cursize %u nitems %u has_event %d\n",
171 f->cursize, f->nitems, f->has_event);
172 s = format (s, " head %d tail %d\n", f->head, f->tail);
176 (s, " server session %d thread %d client session %d thread %d\n",
177 f->master_session_index, f->master_thread_index,
178 f->client_session_index, f->client_thread_index);
182 s = format (s, " ooo pool %d active elts newest %u\n",
183 pool_elts (f->ooo_segments), f->ooos_newest);
184 if (svm_fifo_has_ooo_data (f))
185 s = format (s, " %U", format_ooo_list, f, verbose);
190 /** create an svm fifo, in the current heap. Fails vs blow up the process */
192 svm_fifo_create (u32 data_size_in_bytes)
196 f = clib_mem_alloc_aligned_or_null (sizeof (*f) + data_size_in_bytes,
197 CLIB_CACHE_LINE_BYTES);
201 memset (f, 0, sizeof (*f));
202 f->nitems = data_size_in_bytes;
203 f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX;
208 svm_fifo_free (svm_fifo_t * f)
210 pool_free (f->ooo_segments);
214 always_inline ooo_segment_t *
215 ooo_segment_new (svm_fifo_t * f, u32 start, u32 length)
219 pool_get (f->ooo_segments, s);
224 s->prev = s->next = OOO_SEGMENT_INVALID_INDEX;
230 ooo_segment_del (svm_fifo_t * f, u32 index)
232 ooo_segment_t *cur, *prev = 0, *next = 0;
233 cur = pool_elt_at_index (f->ooo_segments, index);
235 if (cur->next != OOO_SEGMENT_INVALID_INDEX)
237 next = pool_elt_at_index (f->ooo_segments, cur->next);
238 next->prev = cur->prev;
241 if (cur->prev != OOO_SEGMENT_INVALID_INDEX)
243 prev = pool_elt_at_index (f->ooo_segments, cur->prev);
244 prev->next = cur->next;
248 f->ooos_list_head = cur->next;
251 pool_put (f->ooo_segments, cur);
255 * Add segment to fifo's out-of-order segment list. Takes care of merging
256 * adjacent segments and removing overlapping ones.
259 ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
261 ooo_segment_t *s, *new_s, *prev, *next, *it;
262 u32 new_index, s_end_pos, s_index;
263 u32 normalized_position, normalized_end_position;
265 ASSERT (offset + length <= ooo_segment_distance_from_tail (f, f->head));
266 normalized_position = (f->tail + offset) % f->nitems;
267 normalized_end_position = (f->tail + offset + length) % f->nitems;
269 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
271 if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX)
273 s = ooo_segment_new (f, normalized_position, length);
274 f->ooos_list_head = s - f->ooo_segments;
275 f->ooos_newest = f->ooos_list_head;
279 /* Find first segment that starts after new segment */
280 s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
281 while (s->next != OOO_SEGMENT_INVALID_INDEX
282 && position_lt (f, s->start, normalized_position))
283 s = pool_elt_at_index (f->ooo_segments, s->next);
285 /* If we have a previous and we overlap it, use it as starting point */
286 prev = ooo_segment_get_prev (f, s);
288 && position_leq (f, normalized_position, ooo_segment_end_pos (f, prev)))
291 s_end_pos = ooo_segment_end_pos (f, s);
293 /* Since we have previous, normalized start position cannot be smaller
294 * than prev->start. Check tail */
295 ASSERT (position_lt (f, s->start, normalized_position));
299 s_index = s - f->ooo_segments;
300 s_end_pos = ooo_segment_end_pos (f, s);
302 /* No overlap, add before current segment */
303 if (position_lt (f, normalized_end_position, s->start))
305 new_s = ooo_segment_new (f, normalized_position, length);
306 new_index = new_s - f->ooo_segments;
308 /* Pool might've moved, get segment again */
309 s = pool_elt_at_index (f->ooo_segments, s_index);
310 if (s->prev != OOO_SEGMENT_INVALID_INDEX)
312 new_s->prev = s->prev;
313 prev = pool_elt_at_index (f->ooo_segments, new_s->prev);
314 prev->next = new_index;
319 f->ooos_list_head = new_index;
322 new_s->next = s_index;
324 f->ooos_newest = new_index;
327 /* No overlap, add after current segment */
328 else if (position_gt (f, normalized_position, s_end_pos))
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);
336 /* Needs to be last */
337 ASSERT (s->next == OOO_SEGMENT_INVALID_INDEX);
339 new_s->prev = s_index;
341 f->ooos_newest = new_index;
351 if (position_lt (f, normalized_position, s->start))
353 s->start = normalized_position;
354 s->length = position_diff (f, s_end_pos, s->start);
355 f->ooos_newest = s - f->ooo_segments;
360 /* Overlapping tail */
361 if (position_gt (f, normalized_end_position, s_end_pos))
363 s->length = position_diff (f, normalized_end_position, s->start);
365 /* Remove the completely overlapped segments in the tail */
366 it = ooo_segment_next (f, s);
367 while (it && position_leq (f, ooo_segment_end_pos (f, it),
368 normalized_end_position))
370 next = ooo_segment_next (f, it);
371 ooo_segment_del (f, it - f->ooo_segments);
375 /* If partial overlap with last, merge */
376 if (it && position_leq (f, it->start, normalized_end_position))
378 s->length = position_diff (f, ooo_segment_end_pos (f, it),
380 ooo_segment_del (f, it - f->ooo_segments);
382 f->ooos_newest = s - f->ooo_segments;
387 * Removes segments that can now be enqueued because the fifo's tail has
388 * advanced. Returns the number of bytes added to tail.
391 ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued)
394 u32 index, bytes = 0;
397 s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
398 diff = ooo_segment_distance_to_tail (f, s->start);
400 ASSERT (diff != n_bytes_enqueued);
402 if (diff > n_bytes_enqueued)
405 /* If last tail update overlaps one/multiple ooo segments, remove them */
406 while (0 <= diff && diff < n_bytes_enqueued)
408 index = s - f->ooo_segments;
410 /* Segment end is beyond the tail. Advance tail and remove segment */
411 if (s->length > diff)
413 bytes = s->length - diff;
415 f->tail %= f->nitems;
416 ooo_segment_del (f, index);
420 /* If we have next go on */
421 if (s->next != OOO_SEGMENT_INVALID_INDEX)
423 s = pool_elt_at_index (f->ooo_segments, s->next);
424 diff = ooo_segment_distance_to_tail (f, s->start);
425 ooo_segment_del (f, index);
430 ooo_segment_del (f, index);
435 ASSERT (bytes >= 0 && bytes <= f->nitems);
440 svm_fifo_enqueue_internal (svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here)
442 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
445 /* read cursize, which can only increase while we're working */
446 cursize = svm_fifo_max_dequeue (f);
447 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
449 if (PREDICT_FALSE (cursize == f->nitems))
450 return -2; /* fifo stuffed */
454 /* Number of bytes we're going to copy */
455 total_copy_bytes = (nitems - cursize) < max_bytes ?
456 (nitems - cursize) : max_bytes;
458 if (PREDICT_TRUE (copy_from_here != 0))
460 /* Number of bytes in first copy segment */
461 first_copy_bytes = ((nitems - f->tail) < total_copy_bytes)
462 ? (nitems - f->tail) : total_copy_bytes;
464 clib_memcpy (&f->data[f->tail], copy_from_here, first_copy_bytes);
465 f->tail += first_copy_bytes;
466 f->tail = (f->tail == nitems) ? 0 : f->tail;
468 /* Number of bytes in second copy segment, if any */
469 second_copy_bytes = total_copy_bytes - first_copy_bytes;
470 if (second_copy_bytes)
472 clib_memcpy (&f->data[f->tail], copy_from_here + first_copy_bytes,
474 f->tail += second_copy_bytes;
475 f->tail = (f->tail == nitems) ? 0 : f->tail;
482 /* Account for a zero-copy enqueue done elsewhere */
483 ASSERT (max_bytes <= (nitems - cursize));
484 f->tail += max_bytes;
485 f->tail = f->tail % nitems;
486 total_copy_bytes = max_bytes;
489 svm_fifo_trace_add (f, f->head, total_copy_bytes, 2);
491 /* Any out-of-order segments to collect? */
492 if (PREDICT_FALSE (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX))
493 total_copy_bytes += ooo_segment_try_collect (f, total_copy_bytes);
495 /* Atomically increase the queue length */
496 ASSERT (cursize + total_copy_bytes <= nitems);
497 __sync_fetch_and_add (&f->cursize, total_copy_bytes);
499 return (total_copy_bytes);
502 #define SVM_ENQUEUE_CLONE_TEMPLATE(arch, fn, tgt) \
504 __attribute__ ((flatten)) \
505 __attribute__ ((target (tgt))) \
507 fn ## _ ## arch ( svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here) \
508 { return fn (f, max_bytes, copy_from_here);}
511 svm_fifo_enqueue_nowait_ma (svm_fifo_t * f, u32 max_bytes,
514 return svm_fifo_enqueue_internal (f, max_bytes, copy_from_here);
517 foreach_march_variant (SVM_ENQUEUE_CLONE_TEMPLATE,
518 svm_fifo_enqueue_nowait_ma);
519 CLIB_MULTIARCH_SELECT_FN (svm_fifo_enqueue_nowait_ma);
522 svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here)
525 return svm_fifo_enqueue_nowait_ma (f, max_bytes, copy_from_here);
527 static int (*fp) (svm_fifo_t *, u32, u8 *);
529 if (PREDICT_FALSE (fp == 0))
530 fp = (void *) svm_fifo_enqueue_nowait_ma_multiarch_select ();
532 return (*fp) (f, max_bytes, copy_from_here);
537 * Enqueue a future segment.
539 * Two choices: either copies the entire segment, or copies nothing
540 * Returns 0 of the entire segment was copied
541 * Returns -1 if none of the segment was copied due to lack of space
544 svm_fifo_enqueue_with_offset_internal (svm_fifo_t * f,
549 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
550 u32 cursize, nitems, normalized_offset;
551 u32 offset_from_tail;
553 f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
555 /* read cursize, which can only increase while we're working */
556 cursize = svm_fifo_max_dequeue (f);
559 ASSERT (required_bytes < nitems);
561 normalized_offset = (f->tail + offset) % nitems;
563 /* Will this request fit? */
564 offset_from_tail = (nitems + normalized_offset - f->tail) % nitems;
565 if ((required_bytes + offset_from_tail) > (nitems - cursize))
568 svm_fifo_trace_add (f, offset, required_bytes, 1);
570 ooo_segment_add (f, offset, required_bytes);
572 /* Number of bytes we're going to copy */
573 total_copy_bytes = required_bytes;
575 /* Number of bytes in first copy segment */
576 first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes)
577 ? (nitems - normalized_offset) : total_copy_bytes;
579 clib_memcpy (&f->data[normalized_offset], copy_from_here, first_copy_bytes);
581 /* Number of bytes in second copy segment, if any */
582 second_copy_bytes = total_copy_bytes - first_copy_bytes;
583 if (second_copy_bytes)
585 normalized_offset += first_copy_bytes;
586 normalized_offset %= nitems;
588 ASSERT (normalized_offset == 0);
590 clib_memcpy (&f->data[normalized_offset],
591 copy_from_here + first_copy_bytes, second_copy_bytes);
599 svm_fifo_enqueue_with_offset (svm_fifo_t * f,
601 u32 required_bytes, u8 * copy_from_here)
603 return svm_fifo_enqueue_with_offset_internal (f, offset, required_bytes,
609 svm_fifo_dequeue_internal (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
611 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
614 /* read cursize, which can only increase while we're working */
615 cursize = svm_fifo_max_dequeue (f);
616 if (PREDICT_FALSE (cursize == 0))
617 return -2; /* nothing in the fifo */
621 /* Number of bytes we're going to copy */
622 total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes;
624 if (PREDICT_TRUE (copy_here != 0))
626 /* Number of bytes in first copy segment */
627 first_copy_bytes = ((nitems - f->head) < total_copy_bytes)
628 ? (nitems - f->head) : total_copy_bytes;
629 clib_memcpy (copy_here, &f->data[f->head], first_copy_bytes);
630 f->head += first_copy_bytes;
631 f->head = (f->head == nitems) ? 0 : f->head;
633 /* Number of bytes in second copy segment, if any */
634 second_copy_bytes = total_copy_bytes - first_copy_bytes;
635 if (second_copy_bytes)
637 clib_memcpy (copy_here + first_copy_bytes,
638 &f->data[f->head], second_copy_bytes);
639 f->head += second_copy_bytes;
640 f->head = (f->head == nitems) ? 0 : f->head;
646 /* Account for a zero-copy dequeue done elsewhere */
647 ASSERT (max_bytes <= cursize);
648 f->head += max_bytes;
649 f->head = f->head % nitems;
650 cursize -= max_bytes;
651 total_copy_bytes = max_bytes;
654 ASSERT (f->head <= nitems);
655 ASSERT (cursize >= total_copy_bytes);
656 __sync_fetch_and_sub (&f->cursize, total_copy_bytes);
658 return (total_copy_bytes);
662 svm_fifo_dequeue_nowait_ma (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
664 return svm_fifo_dequeue_internal (f, max_bytes, copy_here);
667 #define SVM_FIFO_DEQUEUE_CLONE_TEMPLATE(arch, fn, tgt) \
669 __attribute__ ((flatten)) \
670 __attribute__ ((target (tgt))) \
672 fn ## _ ## arch ( svm_fifo_t * f, u32 max_bytes, \
674 { return fn (f, max_bytes, copy_here);}
676 foreach_march_variant (SVM_FIFO_DEQUEUE_CLONE_TEMPLATE,
677 svm_fifo_dequeue_nowait_ma);
678 CLIB_MULTIARCH_SELECT_FN (svm_fifo_dequeue_nowait_ma);
681 svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
684 return svm_fifo_dequeue_nowait_ma (f, max_bytes, copy_here);
686 static int (*fp) (svm_fifo_t *, u32, u8 *);
688 if (PREDICT_FALSE (fp == 0))
689 fp = (void *) svm_fifo_dequeue_nowait_ma_multiarch_select ();
691 return (*fp) (f, max_bytes, copy_here);
696 svm_fifo_peek_ma (svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
699 u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
700 u32 cursize, nitems, real_head;
702 /* read cursize, which can only increase while we're working */
703 cursize = svm_fifo_max_dequeue (f);
704 if (PREDICT_FALSE (cursize < relative_offset))
705 return -2; /* nothing in the fifo */
708 real_head = f->head + relative_offset;
709 real_head = real_head >= nitems ? real_head - nitems : real_head;
711 /* Number of bytes we're going to copy */
712 total_copy_bytes = (cursize - relative_offset < max_bytes) ?
713 cursize - relative_offset : max_bytes;
715 if (PREDICT_TRUE (copy_here != 0))
717 /* Number of bytes in first copy segment */
719 ((nitems - real_head) < total_copy_bytes) ?
720 (nitems - real_head) : total_copy_bytes;
721 clib_memcpy (copy_here, &f->data[real_head], first_copy_bytes);
723 /* Number of bytes in second copy segment, if any */
724 second_copy_bytes = total_copy_bytes - first_copy_bytes;
725 if (second_copy_bytes)
727 clib_memcpy (copy_here + first_copy_bytes, &f->data[0],
731 return total_copy_bytes;
734 #define SVM_FIFO_PEEK_CLONE_TEMPLATE(arch, fn, tgt) \
736 __attribute__ ((flatten)) \
737 __attribute__ ((target (tgt))) \
739 fn ## _ ## arch ( svm_fifo_t * f, u32 relative_offset, u32 max_bytes, \
741 { return fn (f, relative_offset, max_bytes, copy_here);}
743 foreach_march_variant (SVM_FIFO_PEEK_CLONE_TEMPLATE, svm_fifo_peek_ma);
744 CLIB_MULTIARCH_SELECT_FN (svm_fifo_peek_ma);
747 svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
751 return svm_fifo_peek_ma (f, relative_offset, max_bytes, copy_here);
753 static int (*fp) (svm_fifo_t *, u32, u32, u8 *);
755 if (PREDICT_FALSE (fp == 0))
756 fp = (void *) svm_fifo_peek_ma_multiarch_select ();
758 return (*fp) (f, relative_offset, max_bytes, copy_here);
763 svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes)
765 u32 total_drop_bytes, first_drop_bytes, second_drop_bytes;
768 /* read cursize, which can only increase while we're working */
769 cursize = svm_fifo_max_dequeue (f);
770 if (PREDICT_FALSE (cursize == 0))
771 return -2; /* nothing in the fifo */
775 /* Number of bytes we're going to drop */
776 total_drop_bytes = (cursize < max_bytes) ? cursize : max_bytes;
778 svm_fifo_trace_add (f, f->tail, total_drop_bytes, 3);
780 /* Number of bytes in first copy segment */
782 ((nitems - f->head) < total_drop_bytes) ?
783 (nitems - f->head) : total_drop_bytes;
784 f->head += first_drop_bytes;
785 f->head = (f->head == nitems) ? 0 : f->head;
787 /* Number of bytes in second drop segment, if any */
788 second_drop_bytes = total_drop_bytes - first_drop_bytes;
789 if (second_drop_bytes)
791 f->head += second_drop_bytes;
792 f->head = (f->head == nitems) ? 0 : f->head;
795 ASSERT (f->head <= nitems);
796 ASSERT (cursize >= total_drop_bytes);
797 __sync_fetch_and_sub (&f->cursize, total_drop_bytes);
799 return total_drop_bytes;
803 svm_fifo_number_ooo_segments (svm_fifo_t * f)
805 return pool_elts (f->ooo_segments);
809 svm_fifo_first_ooo_segment (svm_fifo_t * f)
811 return pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
815 * Set fifo pointers to requested offset
818 svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
820 f->head = f->tail = pointer % f->nitems;
824 * fd.io coding-style-patch-verification: ON
827 * eval: (c-set-style "gnu")