On Wed, Feb 11, 2015 at 09:31:35AM +0800, Chen Jing D(Mark) wrote:
>
> +uint16_t
> +fm10k_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
> + uint16_t nb_pkts)
> +{
> + struct rte_mbuf *mbuf;
> + union fm10k_rx_desc desc;
> + struct fm10k_rx_queue *q = rx_queue;
> + uint16_t count = 0;
> + uint16_t nb_rcv, nb_seg;
> + int alloc = 0;
> + uint16_t next_dd;
> + struct rte_mbuf *first_seg = q->pkt_first_seg;
> + struct rte_mbuf *last_seg = q->pkt_last_seg;
> +
> + next_dd = q->next_dd;
> + nb_rcv = 0;
> +
> + nb_seg = RTE_MIN(nb_pkts, q->alloc_thresh);
> + for (count = 0; count < nb_seg; count++) {
> + mbuf = q->sw_ring[next_dd];
> + desc = q->hw_ring[next_dd];
> + if (!(desc.d.staterr & FM10K_RXD_STATUS_DD))
> + break;
> +#ifdef RTE_LIBRTE_FM10K_DEBUG_RX
> + dump_rxd(&desc);
> +#endif
> +
> + if (++next_dd == q->nb_desc) {
> + next_dd = 0;
> + alloc = 1;
> + }
> +
> + /* Prefetch next mbuf while processing current one. */
> + rte_prefetch0(q->sw_ring[next_dd]);
> +
> + /*
> + * When next RX descriptor is on a cache-line boundary,
> + * prefetch the next 4 RX descriptors and the next 8 pointers
> + * to mbufs.
> + */
> + if ((next_dd & 0x3) == 0) {
> + rte_prefetch0(&q->hw_ring[next_dd]);
> + rte_prefetch0(&q->sw_ring[next_dd]);
> + }
> +
> + /* Fill data length */
> + rte_pktmbuf_data_len(mbuf) = desc.w.length;
> +
> + /*
> + * If this is the first buffer of the received packet,
> + * set the pointer to the first mbuf of the packet and
> + * initialize its context.
> + * Otherwise, update the total length and the number of segments
> + * of the current scattered packet, and update the pointer to
> + * the last mbuf of the current packet.
> + */
> + if (!first_seg) {
> + first_seg = mbuf;
> + first_seg->pkt_len = desc.w.length;
> + } else {
> + first_seg->pkt_len =
> + (uint16_t)(first_seg->pkt_len +
> + rte_pktmbuf_data_len(mbuf));
> + first_seg->nb_segs++;
> + last_seg->next = mbuf;
> + }
> +
> + /*
> + * If this is not the last buffer of the received packet,
> + * update the pointer to the last mbuf of the current scattered
> + * packet and continue to parse the RX ring.
> + */
> + if (!(desc.d.staterr & FM10K_RXD_STATUS_EOP)) {
> + last_seg = mbuf;
> + continue;
> + }
> +
> + first_seg->ol_flags = 0;
> +#ifdef RTE_LIBRTE_FM10K_RX_OLFLAGS_ENABLE
> + rx_desc_to_ol_flags(first_seg, &desc);
> +#endif
> + first_seg->hash.rss = desc.d.rss;
> +
> + /* Prefetch data of first segment, if configured to do so. */
> + rte_packet_prefetch((char *)first_seg->buf_addr +
> + first_seg->data_off);
> +
> + /*
> + * Store the mbuf address into the next entry of the array
> + * of returned packets.
> + */
> + rx_pkts[nb_rcv++] = first_seg;
> +
> + /*
> + * Setup receipt context for a new packet.
> + */
> + first_seg = NULL;
> + }
> +
> + q->next_dd = next_dd;
> + q->pkt_first_seg = first_seg;
> + q->pkt_last_seg = last_seg;
> +
> + if ((q->next_dd > q->next_trigger) || (alloc == 1)) {
> + rte_mempool_get_bulk(q->mp, (void **)&q->sw_ring[q->next_alloc],
> + q->alloc_thresh);
Same thing here. The return value should be checked in case the
mempool runs out of buffers.
> + for (; q->next_alloc <= q->next_trigger; ++q->next_alloc) {
> + mbuf = q->sw_ring[q->next_alloc];
> +
> + /* setup static mbuf fields */
> + fm10k_pktmbuf_reset(mbuf, q->port_id);
> +
> + /* write descriptor */
> + desc.q.pkt_addr = MBUF_DMA_ADDR_DEFAULT(mbuf);
> + desc.q.hdr_addr = MBUF_DMA_ADDR_DEFAULT(mbuf);
> + q->hw_ring[q->next_alloc] = desc;
> + }
> + FM10K_PCI_REG_WRITE(q->tail_ptr, q->next_trigger);
> + q->next_trigger += q->alloc_thresh;
> + if (q->next_trigger >= q->nb_desc) {
> + q->next_trigger = q->alloc_thresh - 1;
> + q->next_alloc = 0;
> + }
> + }
> +
> + return nb_rcv;
> +}
> +
