+ ASSERT (f->refcnt > 0);
+
+ if (--f->refcnt == 0)
+ {
+ /* ooo data is not allocated on segment heap */
+ svm_fifo_free_chunk_lookup (f);
+ clib_mem_free (f);
+ }
+}
+
+void
+svm_fifo_overwrite_head (svm_fifo_t * f, u8 * src, u32 len)
+{
+ u32 n_chunk;
+ u32 head, tail, head_idx;
+ svm_fifo_chunk_t *c;
+
+ ASSERT (len <= f->size);
+
+ f_load_head_tail_cons (f, &head, &tail);
+
+ if (!f->head_chunk)
+ f->head_chunk = svm_fifo_find_chunk (f, head);
+
+ c = f->head_chunk;
+ head_idx = head - c->start_byte;
+ n_chunk = c->length - head_idx;
+ if (len <= n_chunk)
+ clib_memcpy_fast (&c->data[head_idx], src, len);
+ else
+ {
+ ASSERT (len - n_chunk <= c->next->length);
+ clib_memcpy_fast (&c->data[head_idx], src, n_chunk);
+ clib_memcpy_fast (&c->next->data[0], src + n_chunk, len - n_chunk);
+ }
+}
+
+static int
+f_try_grow (svm_fifo_t * f, u32 head, u32 tail, u32 len)
+{
+ svm_fifo_chunk_t *c;
+ u32 alloc_size, free_alloced;
+
+ free_alloced = f_chunk_end (f->end_chunk) - tail;
+ ASSERT (free_alloced < len);
+
+ alloc_size = clib_min (f->min_alloc, f->size - (tail - head));
+ alloc_size = clib_max (alloc_size, len - free_alloced);
+
+ c = fsh_alloc_chunk (f->fs_hdr, f->slice_index, alloc_size);
+ if (PREDICT_FALSE (!c))
+ return -1;
+
+ svm_fifo_add_chunk (f, c);
+ return 0;
+}
+
+int
+svm_fifo_enqueue (svm_fifo_t * f, u32 len, const u8 * src)
+{
+ u32 tail, head, free_count;
+ svm_fifo_chunk_t *old_tail_c;
+
+ f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
+
+ f_load_head_tail_prod (f, &head, &tail);
+
+ /* free space in fifo can only increase during enqueue: SPSC */
+ free_count = f_free_count (f, head, tail);
+
+ if (PREDICT_FALSE (free_count == 0))
+ return SVM_FIFO_EFULL;
+
+ /* number of bytes we're going to copy */
+ len = clib_min (free_count, len);
+
+ if (f_pos_gt (tail + len, f_chunk_end (f->end_chunk)))
+ {
+ if (PREDICT_FALSE (f_try_grow (f, head, tail, len)))
+ {
+ len = f_chunk_end (f->end_chunk) - tail;
+ if (!len)
+ return SVM_FIFO_EGROW;
+ }
+ }
+
+ old_tail_c = f->tail_chunk;
+
+ svm_fifo_copy_to_chunk (f, f->tail_chunk, tail, src, len, &f->tail_chunk);
+ tail = tail + len;
+
+ svm_fifo_trace_add (f, head, len, 2);
+
+ /* collect out-of-order segments */
+ if (PREDICT_FALSE (f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX))
+ {
+ len += ooo_segment_try_collect (f, len, &tail);
+ /* Tail chunk might've changed even if nothing was collected */
+ f->tail_chunk = f_lookup_clear_enq_chunks (f, old_tail_c, tail);
+ f->ooo_enq = 0;
+ }
+
+ /* store-rel: producer owned index (paired with load-acq in consumer) */
+ clib_atomic_store_rel_n (&f->tail, tail);
+
+ return len;
+}
+
+/**
+ * Enqueue a future segment.
+ *
+ * Two choices: either copies the entire segment, or copies nothing
+ * Returns 0 of the entire segment was copied
+ * Returns -1 if none of the segment was copied due to lack of space
+ */
+int
+svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 len, u8 * src)
+{
+ u32 tail, head, free_count, enq_pos;
+
+ f_load_head_tail_prod (f, &head, &tail);
+
+ /* free space in fifo can only increase during enqueue: SPSC */
+ free_count = f_free_count (f, head, tail);
+ f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
+
+ /* will this request fit? */
+ if ((len + offset) > free_count)
+ return SVM_FIFO_EFULL;
+
+ enq_pos = tail + offset;
+
+ if (f_pos_gt (enq_pos + len, f_chunk_end (f->end_chunk)))
+ {
+ if (PREDICT_FALSE (f_try_grow (f, head, tail, offset + len)))
+ return SVM_FIFO_EGROW;
+ }
+
+ svm_fifo_trace_add (f, offset, len, 1);
+ ooo_segment_add (f, offset, head, tail, len);
+
+ if (!f->ooo_enq || !f_chunk_includes_pos (f->ooo_enq, enq_pos))
+ f_update_ooo_enq (f, enq_pos, enq_pos + len);
+
+ svm_fifo_copy_to_chunk (f, f->ooo_enq, enq_pos, src, len, &f->ooo_enq);
+
+ return 0;
+}
+
+/**
+ * Advance tail
+ */
+void
+svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 len)
+{
+ u32 tail;
+
+ ASSERT (len <= svm_fifo_max_enqueue_prod (f));
+ /* load-relaxed: producer owned index */
+ tail = f->tail;
+ tail = tail + len;
+
+ if (rb_tree_is_init (&f->ooo_enq_lookup))
+ {
+ f->tail_chunk = f_lookup_clear_enq_chunks (f, f->tail_chunk, tail);
+ f->ooo_enq = 0;
+ }
+ else
+ {
+ f->tail_chunk = svm_fifo_find_next_chunk (f, f->tail_chunk, tail);
+ }
+
+ /* store-rel: producer owned index (paired with load-acq in consumer) */
+ clib_atomic_store_rel_n (&f->tail, tail);
+}
+
+always_inline svm_fifo_chunk_t *
+f_unlink_chunks (svm_fifo_t * f, u32 end_pos, u8 maybe_ooo)
+{
+ svm_fifo_chunk_t *start, *prev = 0, *c;
+ rb_tree_t *rt;
+ rb_node_t *n;
+
+ ASSERT (!f_chunk_includes_pos (f->start_chunk, end_pos));
+
+ if (maybe_ooo)
+ rt = &f->ooo_deq_lookup;
+
+ c = f->start_chunk;
+
+ do
+ {
+ if (maybe_ooo && c->deq_rb_index != RBTREE_TNIL_INDEX)
+ {
+ n = rb_node (rt, c->deq_rb_index);
+ ASSERT (n == f_find_node_rbtree (rt, c->start_byte));
+ rb_tree_del_node (rt, n);
+ c->deq_rb_index = RBTREE_TNIL_INDEX;
+ }
+ if (!c->next)
+ break;
+ prev = c;
+ c = c->next;
+ }
+ while (!f_chunk_includes_pos (c, end_pos));
+
+ if (maybe_ooo)
+ {
+ if (f->ooo_deq && f_pos_lt (f->ooo_deq->start_byte, f_chunk_end (c)))
+ f->ooo_deq = 0;
+ }
+ else
+ {
+ if (PREDICT_FALSE (f->ooo_deq != 0))
+ f->ooo_deq = 0;
+ }
+
+ /* Avoid unlinking the last chunk */
+ if (!prev)
+ return 0;
+
+ prev->next = 0;
+ start = f->start_chunk;
+ f->start_chunk = c;
+
+ return start;
+}
+
+int
+svm_fifo_dequeue (svm_fifo_t * f, u32 len, u8 * dst)
+{
+ u32 tail, head, cursize;
+
+ f_load_head_tail_cons (f, &head, &tail);
+
+ /* current size of fifo can only increase during dequeue: SPSC */
+ cursize = f_cursize (f, head, tail);
+
+ if (PREDICT_FALSE (cursize == 0))
+ return SVM_FIFO_EEMPTY;
+
+ len = clib_min (cursize, len);
+
+ if (!f->head_chunk)
+ f->head_chunk = svm_fifo_find_chunk (f, head);
+
+ svm_fifo_copy_from_chunk (f, f->head_chunk, head, dst, len, &f->head_chunk);
+ head = head + len;
+
+ if (f_pos_geq (head, f_chunk_end (f->start_chunk)))
+ fsh_collect_chunks (f->fs_hdr, f->slice_index,
+ f_unlink_chunks (f, head, 0));
+
+ /* store-rel: consumer owned index (paired with load-acq in producer) */
+ clib_atomic_store_rel_n (&f->head, head);
+
+ return len;
+}
+
+int
+svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 len, u8 * dst)
+{
+ u32 tail, head, cursize, head_idx;
+
+ f_load_head_tail_cons (f, &head, &tail);
+
+ /* current size of fifo can only increase during peek: SPSC */
+ cursize = f_cursize (f, head, tail);
+
+ if (PREDICT_FALSE (cursize < offset))
+ return SVM_FIFO_EEMPTY;
+
+ len = clib_min (cursize - offset, len);
+ head_idx = head + offset;
+
+ if (!f->ooo_deq || !f_chunk_includes_pos (f->ooo_deq, head_idx))
+ f_update_ooo_deq (f, head_idx, head_idx + len);
+
+ svm_fifo_copy_from_chunk (f, f->ooo_deq, head_idx, dst, len, &f->ooo_deq);
+ return len;
+}
+
+int
+svm_fifo_dequeue_drop (svm_fifo_t * f, u32 len)
+{
+ u32 total_drop_bytes, tail, head, cursize;
+
+ f_load_head_tail_cons (f, &head, &tail);
+
+ /* number of bytes available */
+ cursize = f_cursize (f, head, tail);
+ if (PREDICT_FALSE (cursize == 0))
+ return SVM_FIFO_EEMPTY;
+
+ /* number of bytes we're going to drop */
+ total_drop_bytes = clib_min (cursize, len);
+
+ svm_fifo_trace_add (f, tail, total_drop_bytes, 3);
+
+ /* move head */
+ head = head + total_drop_bytes;
+
+ if (f_pos_geq (head, f_chunk_end (f->start_chunk)))
+ {
+ fsh_collect_chunks (f->fs_hdr, f->slice_index,
+ f_unlink_chunks (f, head, 1));
+ f->head_chunk =
+ f_chunk_includes_pos (f->start_chunk, head) ? f->start_chunk : 0;
+ }
+
+ /* store-rel: consumer owned index (paired with load-acq in producer) */
+ clib_atomic_store_rel_n (&f->head, head);
+
+ return total_drop_bytes;
+}
+
+/**
+ * Drop all data from fifo
+ *
+ * Should be called only from vpp side because of lookup cleanup
+ */
+void
+svm_fifo_dequeue_drop_all (svm_fifo_t * f)
+{
+ u32 head, tail;
+
+ f_load_head_tail_all_acq (f, &head, &tail);
+
+ if (!f->head_chunk || !f_chunk_includes_pos (f->head_chunk, head))
+ f->head_chunk = svm_fifo_find_chunk (f, head);
+
+ f->head_chunk = f_lookup_clear_deq_chunks (f, f->head_chunk, tail);
+
+ if (f_pos_geq (tail, f_chunk_end (f->start_chunk)))
+ fsh_collect_chunks (f->fs_hdr, f->slice_index,
+ f_unlink_chunks (f, tail, 0));
+
+ /* store-rel: consumer owned index (paired with load-acq in producer) */
+ clib_atomic_store_rel_n (&f->head, tail);
+}
+
+int
+svm_fifo_fill_chunk_list (svm_fifo_t * f)
+{
+ u32 head, tail;
+
+ f_load_head_tail_prod (f, &head, &tail);
+
+ if (f_chunk_end (f->end_chunk) - head >= f->size)
+ return 0;
+
+ if (f_try_grow (f, head, tail, f->size - (tail - head)))
+ return SVM_FIFO_EGROW;
+
+ return 0;
+}
+
+int
+svm_fifo_segments (svm_fifo_t * f, svm_fifo_seg_t * fs)
+{
+ u32 cursize, head, tail, head_idx;
+
+ f_load_head_tail_cons (f, &head, &tail);
+
+ /* consumer function, cursize can only increase while we're working */
+ cursize = f_cursize (f, head, tail);
+
+ if (PREDICT_FALSE (cursize == 0))
+ return SVM_FIFO_EEMPTY;
+
+ head_idx = head;
+
+ if (tail < head)
+ {
+ fs[0].len = f->size - head_idx;
+ fs[0].data = f->head_chunk->data + head_idx;
+ fs[1].len = cursize - fs[0].len;
+ fs[1].data = f->head_chunk->data;
+ }
+ else
+ {
+ fs[0].len = cursize;
+ fs[0].data = f->head_chunk->data + head_idx;
+ fs[1].len = 0;
+ fs[1].data = 0;
+ }
+ return cursize;
+}
+
+void
+svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_seg_t * fs)
+{
+ u32 head;
+
+ /* consumer owned index */
+ head = f->head;
+
+ ASSERT (fs[0].data == f->head_chunk->data + head);
+ head = (head + fs[0].len + fs[1].len);
+ /* store-rel: consumer owned index (paired with load-acq in producer) */
+ clib_atomic_store_rel_n (&f->head, head);
+}
+
+/**
+ * Clones fifo
+ *
+ * Assumptions:
+ * - no prod and cons are accessing either dest or src fifo
+ * - fifo is not multi chunk
+ */
+void
+svm_fifo_clone (svm_fifo_t * df, svm_fifo_t * sf)
+{
+ u32 head, tail;
+
+ /* Support only single chunk clones for now */
+ ASSERT (svm_fifo_n_chunks (sf) == 1);
+
+ clib_memcpy_fast (df->head_chunk->data, sf->head_chunk->data, sf->size);
+
+ f_load_head_tail_all_acq (sf, &head, &tail);
+ clib_atomic_store_rel_n (&df->head, head);
+ clib_atomic_store_rel_n (&df->tail, tail);
+}
+
+u32
+svm_fifo_n_ooo_segments (svm_fifo_t * f)
+{
+ return pool_elts (f->ooo_segments);
+}
+
+ooo_segment_t *
+svm_fifo_first_ooo_segment (svm_fifo_t * f)
+{
+ return pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
+}
+
+/**
+ * Set fifo pointers to requested offset
+ */
+void
+svm_fifo_init_pointers (svm_fifo_t * f, u32 head, u32 tail)
+{
+ svm_fifo_chunk_t *c;
+
+ clib_atomic_store_rel_n (&f->head, head);
+ clib_atomic_store_rel_n (&f->tail, tail);
+
+ c = svm_fifo_find_chunk (f, head);
+ ASSERT (c != 0);
+ f->head_chunk = f->ooo_deq = c;
+ c = svm_fifo_find_chunk (f, tail);
+ ASSERT (c != 0);
+ f->tail_chunk = f->ooo_enq = c;
+}
+
+void
+svm_fifo_add_subscriber (svm_fifo_t * f, u8 subscriber)
+{
+ if (f->n_subscribers >= SVM_FIFO_MAX_EVT_SUBSCRIBERS)
+ return;
+ f->subscribers[f->n_subscribers++] = subscriber;
+}
+
+void
+svm_fifo_del_subscriber (svm_fifo_t * f, u8 subscriber)
+{
+ int i;
+
+ for (i = 0; i < f->n_subscribers; i++)
+ {
+ if (f->subscribers[i] != subscriber)
+ continue;
+ f->subscribers[i] = f->subscribers[f->n_subscribers - 1];
+ f->n_subscribers--;
+ break;
+ }
+}
+
+u8
+svm_fifo_is_sane (svm_fifo_t * f)
+{
+ svm_fifo_chunk_t *tmp;
+
+ if (f->head_chunk && !f_chunk_includes_pos (f->head_chunk, f->head))
+ return 0;
+ if (f->tail_chunk && !f_chunk_includes_pos (f->tail_chunk, f->tail))
+ return 0;
+ if (f->ooo_deq)
+ {
+ if (rb_tree_is_init (&f->ooo_deq_lookup))
+ {
+ if (f_pos_lt (f->ooo_deq->start_byte, f->start_chunk->start_byte)
+ || f_pos_gt (f->ooo_deq->start_byte,
+ f_chunk_end (f->end_chunk)))
+ return 0;
+
+ tmp = f_find_chunk_rbtree (&f->ooo_deq_lookup,
+ f->ooo_deq->start_byte);
+ }
+ else
+ tmp = svm_fifo_find_chunk (f, f->ooo_deq->start_byte);
+ if (tmp != f->ooo_deq)
+ return 0;
+ }
+ if (f->ooo_enq)
+ {
+ if (rb_tree_is_init (&f->ooo_enq_lookup))
+ {
+ if (f_pos_lt (f->ooo_enq->start_byte, f->start_chunk->start_byte)
+ || f_pos_gt (f->ooo_enq->start_byte,
+ f_chunk_end (f->end_chunk)))
+ return 0;
+
+ tmp = f_find_chunk_rbtree (&f->ooo_enq_lookup,
+ f->ooo_enq->start_byte);
+ }
+ else
+ {
+ tmp = svm_fifo_find_next_chunk (f, f->tail_chunk,
+ f->ooo_enq->start_byte);
+ }
+ if (tmp != f->ooo_enq)
+ return 0;
+ }
+
+ if (f->start_chunk->next)
+ {
+ svm_fifo_chunk_t *c, *prev = 0, *tmp;
+ u32 chunks_bytes = 0;
+
+ c = f->start_chunk;
+ do
+ {
+ tmp = svm_fifo_find_chunk (f, c->start_byte);
+ if (tmp != c)
+ return 0;
+ if (prev && (prev->start_byte + prev->length != c->start_byte))
+ return 0;
+
+ if (c->enq_rb_index != RBTREE_TNIL_INDEX)
+ {
+ tmp = f_find_chunk_rbtree (&f->ooo_enq_lookup, c->start_byte);
+ if (tmp)
+ {
+ if (tmp != c)
+ return 0;
+ }
+ }
+ if (c->deq_rb_index != RBTREE_TNIL_INDEX)
+ {
+ tmp = f_find_chunk_rbtree (&f->ooo_deq_lookup, c->start_byte);
+ if (tmp)
+ {
+ if (tmp != c)
+ return 0;
+ }
+ }
+
+ chunks_bytes += c->length;
+ prev = c;
+ c = c->next;
+ }
+ while (c);
+
+ if (chunks_bytes < f->tail - f->head)
+ return 0;
+ }
+
+ return 1;
+}
+
+u32
+svm_fifo_n_chunks (svm_fifo_t * f)
+{
+ svm_fifo_chunk_t *c;
+ int n_chunks = 0;
+
+ c = f->start_chunk;
+ while (c)
+ {
+ n_chunks++;
+ c = c->next;
+ }
+
+ return n_chunks;
+}
+
+u8 *
+format_ooo_segment (u8 * s, va_list * args)
+{
+ svm_fifo_t __clib_unused *f = va_arg (*args, svm_fifo_t *);
+ ooo_segment_t *seg = va_arg (*args, ooo_segment_t *);
+ s = format (s, "[%u, %u], len %u, next %d, prev %d", seg->start,
+ seg->start + seg->length, seg->length, seg->next, seg->prev);
+ return s;
+}
+
+u8 *
+svm_fifo_dump_trace (u8 * s, svm_fifo_t * f)
+{
+#if SVM_FIFO_TRACE
+ svm_fifo_trace_elem_t *seg = 0;
+ int i = 0;
+
+ if (f->trace)
+ {
+ vec_foreach (seg, f->trace)
+ {
+ s = format (s, "{%u, %u, %u}, ", seg->offset, seg->len, seg->action);
+ i++;
+ if (i % 5 == 0)
+ s = format (s, "\n");
+ }
+ s = format (s, "\n");
+ }
+ return s;
+#else
+ return 0;
+#endif
+}
+
+u8 *
+svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose)
+{
+ int i, trace_len;
+ u8 *data = 0;
+ svm_fifo_trace_elem_t *trace;
+ u32 offset;
+ svm_fifo_t *dummy_fifo;
+
+ if (!f)
+ return s;
+
+#if SVM_FIFO_TRACE
+ trace = f->trace;
+ trace_len = vec_len (trace);
+#else
+ trace = 0;
+ trace_len = 0;
+#endif
+
+ dummy_fifo = svm_fifo_alloc (f->size);
+ svm_fifo_init (f, f->size);
+ clib_memset (f->head_chunk->data, 0xFF, f->size);
+ vec_validate (data, f->size);
+ for (i = 0; i < vec_len (data); i++)
+ data[i] = i;
+
+ for (i = 0; i < trace_len; i++)
+ {
+ offset = trace[i].offset;
+ if (trace[i].action == 1)
+ {
+ if (verbose)
+ s = format (s, "adding [%u, %u]:", trace[i].offset,
+ (trace[i].offset + trace[i].len));
+ svm_fifo_enqueue_with_offset (dummy_fifo, trace[i].offset,
+ trace[i].len, &data[offset]);
+ }
+ else if (trace[i].action == 2)
+ {
+ if (verbose)
+ s = format (s, "adding [%u, %u]:", 0, trace[i].len);
+ svm_fifo_enqueue (dummy_fifo, trace[i].len, &data[offset]);
+ }
+ else if (!no_read)
+ {
+ if (verbose)
+ s = format (s, "read: %u", trace[i].len);
+ svm_fifo_dequeue_drop (dummy_fifo, trace[i].len);
+ }
+ if (verbose)
+ s = format (s, "%U", format_svm_fifo, dummy_fifo, 1);
+ }
+
+ s = format (s, "result: %U", format_svm_fifo, dummy_fifo, 1);
+
+ return s;
+}
+
+u8 *
+format_ooo_list (u8 * s, va_list * args)
+{
+ svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
+ u32 indent = va_arg (*args, u32);
+ u32 ooo_segment_index = f->ooos_list_head;
+ ooo_segment_t *seg;
+
+ while (ooo_segment_index != OOO_SEGMENT_INVALID_INDEX)
+ {
+ seg = pool_elt_at_index (f->ooo_segments, ooo_segment_index);
+ s = format (s, "%U%U\n", format_white_space, indent, format_ooo_segment,
+ f, seg);
+ ooo_segment_index = seg->next;
+ }
+
+ return s;
+}
+
+u8 *
+format_svm_fifo (u8 * s, va_list * args)
+{
+ svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
+ int verbose = va_arg (*args, int);
+ u32 indent;
+
+ if (!s)
+ return s;
+
+ indent = format_get_indent (s);
+ s = format (s, "cursize %u nitems %u has_event %d min_alloc %u\n",
+ svm_fifo_max_dequeue (f), f->size, f->has_event, f->min_alloc);
+ s = format (s, "%Uhead %u tail %u segment manager %u\n", format_white_space,
+ indent, f->head, f->tail, f->segment_manager);
+
+ if (verbose > 1)
+ s = format (s, "%Uvpp session %d thread %d app session %d thread %d\n",
+ format_white_space, indent, f->master_session_index,
+ f->master_thread_index, f->client_session_index,
+ f->client_thread_index);
+
+ if (verbose)
+ {
+ s = format (s, "%Uooo pool %d active elts newest %u\n",
+ format_white_space, indent, pool_elts (f->ooo_segments),
+ f->ooos_newest);
+ if (svm_fifo_has_ooo_data (f))
+ s = format (s, " %U", format_ooo_list, f, indent, verbose);
+ }
+ return s;