ixgbe: code refactoring

   - ixgbe_rx_alloc_bufs():
      - Reset the rte_mbuf fields only when requested.
      - Take the RDT update out of the function.
      - Add the stub when RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC is not defined.
   - ixgbe_recv_scattered_pkts():
      - Take the code that updates the fields of the cluster's HEAD buffer into
        the inline function.

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
index 7173db8..c2bcecb 100644 (file)
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
@@ -1021,7 +1021,7 @@ ixgbe_rx_scan_hw_ring(struct ixgbe_rx_queue *rxq)
 }
 
 static inline int
-ixgbe_rx_alloc_bufs(struct ixgbe_rx_queue *rxq)
+ixgbe_rx_alloc_bufs(struct ixgbe_rx_queue *rxq, bool reset_mbuf)
 {
        volatile union ixgbe_adv_rx_desc *rxdp;
        struct ixgbe_rx_entry *rxep;
@@ -1042,11 +1042,14 @@ ixgbe_rx_alloc_bufs(struct ixgbe_rx_queue *rxq)
        for (i = 0; i < rxq->rx_free_thresh; ++i) {
                /* populate the static rte mbuf fields */
                mb = rxep[i].mbuf;
+               if (reset_mbuf) {
+                       mb->next = NULL;
+                       mb->nb_segs = 1;
+                       mb->port = rxq->port_id;
+               }
+
                rte_mbuf_refcnt_set(mb, 1);
-               mb->next = NULL;
                mb->data_off = RTE_PKTMBUF_HEADROOM;
-               mb->nb_segs = 1;
-               mb->port = rxq->port_id;
 
                /* populate the descriptors */
                dma_addr = rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(mb));
@@ -1054,10 +1057,6 @@ ixgbe_rx_alloc_bufs(struct ixgbe_rx_queue *rxq)
                rxdp[i].read.pkt_addr = dma_addr;
        }
 
-       /* update tail pointer */
-       rte_wmb();
-       IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr, rxq->rx_free_trigger);
-
        /* update state of internal queue structure */
        rxq->rx_free_trigger = rxq->rx_free_trigger + rxq->rx_free_thresh;
        if (rxq->rx_free_trigger >= rxq->nb_rx_desc)
@@ -1109,7 +1108,9 @@ rx_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 
        /* if required, allocate new buffers to replenish descriptors */
        if (rxq->rx_tail > rxq->rx_free_trigger) {
-               if (ixgbe_rx_alloc_bufs(rxq) != 0) {
+               uint16_t cur_free_trigger = rxq->rx_free_trigger;
+
+               if (ixgbe_rx_alloc_bufs(rxq, true) != 0) {
                        int i, j;
                        PMD_RX_LOG(DEBUG, "RX mbuf alloc failed port_id=%u "
                                   "queue_id=%u", (unsigned) rxq->port_id,
@@ -1129,6 +1130,10 @@ rx_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 
                        return 0;
                }
+
+               /* update tail pointer */
+               rte_wmb();
+               IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr, cur_free_trigger);
        }
 
        if (rxq->rx_tail >= rxq->nb_rx_desc)
@@ -1179,6 +1184,12 @@ ixgbe_recv_pkts_bulk_alloc(__rte_unused void *rx_queue,
        return 0;
 }
 
+static inline int
+ixgbe_rx_alloc_bufs(__rte_unused struct ixgbe_rx_queue *rxq,
+                   __rte_unused bool reset_mbuf)
+{
+       return -ENOMEM;
+}
 #endif /* RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC */
 
 uint16_t
@@ -1363,6 +1374,64 @@ ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
        return (nb_rx);
 }
 
+/**
+ * Detect an RSC descriptor.
+ */
+static inline uint32_t
+ixgbe_rsc_count(union ixgbe_adv_rx_desc *rx)
+{
+       return (rte_le_to_cpu_32(rx->wb.lower.lo_dword.data) &
+               IXGBE_RXDADV_RSCCNT_MASK) >> IXGBE_RXDADV_RSCCNT_SHIFT;
+}
+
+/**
+ * ixgbe_fill_cluster_head_buf - fill the first mbuf of the returned packet
+ *
+ * Fill the following info in the HEAD buffer of the Rx cluster:
+ *    - RX port identifier
+ *    - hardware offload data, if any:
+ *      - RSS flag & hash
+ *      - IP checksum flag
+ *      - VLAN TCI, if any
+ *      - error flags
+ * @head HEAD of the packet cluster
+ * @desc HW descriptor to get data from
+ * @port_id Port ID of the Rx queue
+ */
+static inline void
+ixgbe_fill_cluster_head_buf(
+       struct rte_mbuf *head,
+       union ixgbe_adv_rx_desc *desc,
+       uint8_t port_id,
+       uint32_t staterr)
+{
+       uint32_t hlen_type_rss;
+       uint64_t pkt_flags;
+
+       head->port = port_id;
+
+       /*
+        * The vlan_tci field is only valid when PKT_RX_VLAN_PKT is
+        * set in the pkt_flags field.
+        */
+       head->vlan_tci = rte_le_to_cpu_16(desc->wb.upper.vlan);
+       hlen_type_rss = rte_le_to_cpu_32(desc->wb.lower.lo_dword.data);
+       pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(hlen_type_rss);
+       pkt_flags |= rx_desc_status_to_pkt_flags(staterr);
+       pkt_flags |= rx_desc_error_to_pkt_flags(staterr);
+       head->ol_flags = pkt_flags;
+
+       if (likely(pkt_flags & PKT_RX_RSS_HASH))
+               head->hash.rss = rte_le_to_cpu_32(desc->wb.lower.hi_dword.rss);
+       else if (pkt_flags & PKT_RX_FDIR) {
+               head->hash.fdir.hash =
+                       rte_le_to_cpu_16(desc->wb.lower.hi_dword.csum_ip.csum)
+                                                         & IXGBE_ATR_HASH_MASK;
+               head->hash.fdir.id =
+                       rte_le_to_cpu_16(desc->wb.lower.hi_dword.csum_ip.ip_id);
+       }
+}
+
 uint16_t
 ixgbe_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
                          uint16_t nb_pkts)
@@ -1379,12 +1448,10 @@ ixgbe_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
        union ixgbe_adv_rx_desc rxd;
        uint64_t dma; /* Physical address of mbuf data buffer */
        uint32_t staterr;
-       uint32_t hlen_type_rss;
        uint16_t rx_id;
        uint16_t nb_rx;
        uint16_t nb_hold;
        uint16_t data_len;
-       uint64_t pkt_flags;
 
        nb_rx = 0;
        nb_hold = 0;
@@ -1542,40 +1609,9 @@ ixgbe_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
                                        (uint16_t) (data_len - ETHER_CRC_LEN);
                }
 
-               /*
-                * Initialize the first mbuf of the returned packet:
-                *    - RX port identifier,
-                *    - hardware offload data, if any:
-                *      - RSS flag & hash,
-                *      - IP checksum flag,
-                *      - VLAN TCI, if any,
-                *      - error flags.
-                */
-               first_seg->port = rxq->port_id;
-
-               /*
-                * The vlan_tci field is only valid when PKT_RX_VLAN_PKT is
-                * set in the pkt_flags field.
-                */
-               first_seg->vlan_tci = rte_le_to_cpu_16(rxd.wb.upper.vlan);
-               hlen_type_rss = rte_le_to_cpu_32(rxd.wb.lower.lo_dword.data);
-               pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(hlen_type_rss);
-               pkt_flags = (pkt_flags |
-                               rx_desc_status_to_pkt_flags(staterr));
-               pkt_flags = (pkt_flags |
-                               rx_desc_error_to_pkt_flags(staterr));
-               first_seg->ol_flags = pkt_flags;
-
-               if (likely(pkt_flags & PKT_RX_RSS_HASH))
-                       first_seg->hash.rss =
-                                   rte_le_to_cpu_32(rxd.wb.lower.hi_dword.rss);
-               else if (pkt_flags & PKT_RX_FDIR) {
-                       first_seg->hash.fdir.hash =
-                           rte_le_to_cpu_16(rxd.wb.lower.hi_dword.csum_ip.csum)
-                                          & IXGBE_ATR_HASH_MASK;
-                       first_seg->hash.fdir.id =
-                         rte_le_to_cpu_16(rxd.wb.lower.hi_dword.csum_ip.ip_id);
-               }
+               /* Initialize the first mbuf of the returned packet */
+               ixgbe_fill_cluster_head_buf(first_seg, &rxd, rxq->port_id,
+                                           staterr);
 
                /* Prefetch data of first segment, if configured to do so. */
                rte_packet_prefetch((char *)first_seg->buf_addr +