+static_always_inline uword
+memif_interface_tx_zc_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * frame, memif_if_t * mif,
+ memif_queue_t * mq,
+ memif_per_thread_data_t * ptd)
+{
+ memif_ring_t *ring = mq->ring;
+ u32 *buffers = vlib_frame_args (frame);
+ u32 n_left = frame->n_vectors;
+ u16 slot, free_slots, n_free;
+ u16 ring_size = 1 << mq->log2_ring_size;
+ u16 mask = ring_size - 1;
+ int n_retries = 5;
+ vlib_buffer_t *b0;
+
+retry:
+ n_free = ring->tail - mq->last_tail;
+ if (n_free >= 16)
+ {
+ vlib_buffer_free_from_ring_no_next (vm, mq->buffers,
+ mq->last_tail & mask,
+ ring_size, n_free);
+ mq->last_tail += n_free;
+ }
+
+ slot = ring->head;
+ free_slots = ring_size - ring->head + mq->last_tail;
+
+ while (n_left && free_slots)
+ {
+ u16 s0;
+ u16 slots_in_packet = 1;
+ memif_desc_t *d0;
+ u32 bi0;
+
+ CLIB_PREFETCH (&ring->desc[(slot + 8) & mask], CLIB_CACHE_LINE_BYTES,
+ STORE);
+
+ if (PREDICT_TRUE (n_left >= 4))
+ vlib_prefetch_buffer_header (vlib_get_buffer (vm, buffers[3]), LOAD);
+
+ bi0 = buffers[0];
+
+ next_in_chain:
+ s0 = slot & mask;
+ d0 = &ring->desc[s0];
+ mq->buffers[s0] = bi0;
+ b0 = vlib_get_buffer (vm, bi0);
+
+ d0->region = b0->buffer_pool_index + 1;
+ d0->offset = (void *) b0->data + b0->current_data -
+ mif->regions[d0->region].shm;
+ d0->length = b0->current_length;
+
+ free_slots--;
+ slot++;
+
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_NEXT_PRESENT))
+ {
+ if (PREDICT_FALSE (free_slots == 0))
+ {
+ /* revert to last fully processed packet */
+ free_slots += slots_in_packet;
+ slot -= slots_in_packet;
+ goto no_free_slots;
+ }
+
+ d0->flags = MEMIF_DESC_FLAG_NEXT;
+ bi0 = b0->next_buffer;
+
+ /* next */
+ slots_in_packet++;
+ goto next_in_chain;
+ }
+
+ d0->flags = 0;
+
+ /* next from */
+ buffers++;
+ n_left--;
+ }
+no_free_slots:
+
+ CLIB_MEMORY_STORE_BARRIER ();
+ ring->head = slot;
+
+ if (n_left && n_retries--)
+ goto retry;
+
+ clib_spinlock_unlock_if_init (&mif->lockp);
+
+ if (n_left)
+ {
+ vlib_error_count (vm, node->node_index, MEMIF_TX_ERROR_NO_FREE_SLOTS,
+ n_left);
+ vlib_buffer_free (vm, buffers, n_left);
+ }
+
+ if ((ring->flags & MEMIF_RING_FLAG_MASK_INT) == 0 && mq->int_fd > -1)
+ {
+ u64 b = 1;
+ CLIB_UNUSED (int r) = write (mq->int_fd, &b, sizeof (b));
+ mq->int_count++;
+ }
+
+ return frame->n_vectors;
+}
+