+ memif_desc_t *d0;
+ void *mb0;
+ i32 src_off;
+ u32 bi0, dst_off, src_left, dst_left, bytes_to_copy;
+ u32 saved_ptd_copy_ops_len = _vec_len (ptd->copy_ops);
+ u32 saved_ptd_buffers_len = _vec_len (ptd->buffers);
+ u16 saved_slot = slot;
+
+ CLIB_PREFETCH (&ring->desc[(slot + 8) & mask], CLIB_CACHE_LINE_BYTES,
+ LOAD);
+
+ d0 = &ring->desc[slot & mask];
+ if (PREDICT_FALSE (last_region != d0->region))
+ {
+ last_region_shm = mif->regions[d0->region].shm;
+ last_region = d0->region;
+ }
+ mb0 = last_region_shm + d0->offset;
+
+ dst_off = 0;
+
+ /* slave is the producer, so it should be able to reset buffer length */
+ dst_left = (type == MEMIF_RING_S2M) ? mif->run.buffer_size : d0->length;
+
+ if (PREDICT_TRUE (n_left >= 4))
+ vlib_prefetch_buffer_header (vlib_get_buffer (vm, buffers[3]), LOAD);
+ bi0 = buffers[0];
+
+ next_in_chain:
+
+ b0 = vlib_get_buffer (vm, bi0);
+ src_off = b0->current_data;
+ src_left = b0->current_length;
+
+ while (src_left)
+ {
+ if (PREDICT_FALSE (dst_left == 0))
+ {
+ if (free_slots)
+ {
+ slot++;
+ free_slots--;
+ d0->flags = MEMIF_DESC_FLAG_NEXT;
+ d0 = &ring->desc[slot & mask];
+ dst_off = 0;
+ dst_left =
+ (type ==
+ MEMIF_RING_S2M) ? mif->run.buffer_size : d0->length;
+
+ if (PREDICT_FALSE (last_region != d0->region))
+ {
+ last_region_shm = mif->regions[d0->region].shm;
+ last_region = d0->region;
+ }
+ mb0 = last_region_shm + d0->offset;
+ }
+ else
+ {
+ /* we need to rollback vectors before bailing out */
+ _vec_len (ptd->buffers) = saved_ptd_buffers_len;
+ _vec_len (ptd->copy_ops) = saved_ptd_copy_ops_len;
+ vlib_error_count (vm, node->node_index,
+ MEMIF_TX_ERROR_ROLLBACK, 1);
+ slot = saved_slot;
+ goto no_free_slots;
+ }
+ }
+ bytes_to_copy = clib_min (src_left, dst_left);
+ memif_add_copy_op (ptd, mb0 + dst_off, bytes_to_copy, src_off,
+ vec_len (ptd->buffers));
+ vec_add1_aligned (ptd->buffers, bi0, CLIB_CACHE_LINE_BYTES);
+ src_off += bytes_to_copy;
+ dst_off += bytes_to_copy;
+ src_left -= bytes_to_copy;
+ dst_left -= bytes_to_copy;
+ }
+
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_NEXT_PRESENT))
+ {
+ bi0 = b0->next_buffer;
+ goto next_in_chain;
+ }
+
+ d0->length = dst_off;
+ d0->flags = 0;
+
+ free_slots -= 1;
+ slot += 1;
+