svm: support for multi-segment enqueues
Type: feature
Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I06c7022a6afbb146b23cbd3a430497ec9e8be73d
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index d357eb6..f1ac8d4 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -955,6 +955,87 @@
clib_atomic_store_rel_n (&f->tail, tail);
}
+int
+svm_fifo_enqueue_segments (svm_fifo_t * f, const svm_fifo_seg_t segs[],
+ u32 n_segs, u8 allow_partial)
+{
+ u32 tail, head, free_count, len = 0, i;
+ 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;
+
+ for (i = 0; i < n_segs; i++)
+ len += segs[i].len;
+
+ old_tail_c = f->tail_chunk;
+
+ if (!allow_partial)
+ {
+ if (PREDICT_FALSE (free_count < len))
+ return SVM_FIFO_EFULL;
+
+ if (f_pos_gt (tail + len, f_chunk_end (f->end_chunk)))
+ {
+ if (PREDICT_FALSE (f_try_chunk_alloc (f, head, tail, len)))
+ return SVM_FIFO_EGROW;
+ }
+
+ for (i = 0; i < n_segs; i++)
+ {
+ svm_fifo_copy_to_chunk (f, f->tail_chunk, tail, segs[i].data,
+ segs[i].len, &f->tail_chunk);
+ tail += segs[i].len;
+ }
+ }
+ else
+ {
+ len = clib_min (free_count, len);
+
+ if (f_pos_gt (tail + len, f_chunk_end (f->end_chunk)))
+ {
+ if (PREDICT_FALSE (f_try_chunk_alloc (f, head, tail, len)))
+ {
+ len = f_chunk_end (f->end_chunk) - tail;
+ if (!len)
+ return SVM_FIFO_EGROW;
+ }
+ }
+
+ i = 0;
+ while (len)
+ {
+ u32 to_copy = clib_min (segs[i].len, len);
+ svm_fifo_copy_to_chunk (f, f->tail_chunk, tail, segs[i].data,
+ to_copy, &f->tail_chunk);
+ len -= to_copy;
+ tail += to_copy;
+ i++;
+ }
+ }
+
+ /* 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;
+}
+
always_inline svm_fifo_chunk_t *
f_unlink_chunks (svm_fifo_t * f, u32 end_pos, u8 maybe_ooo)
{