enic: fix error packets handling

If the packet_error bit in the completion descriptor is set, the
remainder of the descriptor and data are invalid. PKT_RX_MAC_ERR
was set in the mbuf->ol_flags if packet_error was set and used
later to indicate an error packet. But since PKT_RX_MAC_ERR is
defined as 0, mbuf flags and packet types and length were being
misinterpreted.

Make the function enic_cq_rx_to_pkt_err_flags() return true for error
packets and use the return value instead of mbuf->ol_flags to indicate
error packets. Also remove warning for error packets and rely on
rx_error stats.

Fixes: 947d860c821f ("enic: improve Rx performance")

Signed-off-by: John Daley <johndale@cisco.com>

diff --git a/drivers/net/enic/enic_rx.c b/drivers/net/enic/enic_rx.c
index 59ebaa4..817a891 100644 (file)
--- a/drivers/net/enic/enic_rx.c
+++ b/drivers/net/enic/enic_rx.c
@@ -129,13 +129,6 @@ enic_cq_rx_desc_rss_hash(struct cq_enet_rq_desc *cqrd)
        return le32_to_cpu(cqrd->rss_hash);
 }
 
-static inline uint8_t
-enic_cq_rx_desc_fcs_ok(struct cq_enet_rq_desc *cqrd)
-{
-       return ((cqrd->flags & CQ_ENET_RQ_DESC_FLAGS_FCS_OK) ==
-               CQ_ENET_RQ_DESC_FLAGS_FCS_OK);
-}
-
 static inline uint16_t
 enic_cq_rx_desc_vlan(struct cq_enet_rq_desc *cqrd)
 {
@@ -150,25 +143,21 @@ enic_cq_rx_desc_n_bytes(struct cq_desc *cqd)
                CQ_ENET_RQ_DESC_BYTES_WRITTEN_MASK;
 }
 
-static inline uint64_t
-enic_cq_rx_to_pkt_err_flags(struct cq_desc *cqd)
+static inline uint8_t
+enic_cq_rx_to_pkt_err_flags(struct cq_desc *cqd, uint64_t *pkt_err_flags_out)
 {
        struct cq_enet_rq_desc *cqrd = (struct cq_enet_rq_desc *)cqd;
        uint16_t bwflags;
+       int ret = 0;
        uint64_t pkt_err_flags = 0;
 
        bwflags = enic_cq_rx_desc_bwflags(cqrd);
-
-       /* Check for packet error. Can't be more specific than MAC error */
-       if (enic_cq_rx_desc_packet_error(bwflags)) {
-               pkt_err_flags |= PKT_RX_MAC_ERR;
-       }
-
-       /* Check for bad FCS. MAC error isn't quite, but no other choice */
-       if (!enic_cq_rx_desc_fcs_ok(cqrd)) {
-               pkt_err_flags |= PKT_RX_MAC_ERR;
+       if (unlikely(enic_cq_rx_desc_packet_error(bwflags))) {
+               pkt_err_flags = PKT_RX_MAC_ERR;
+               ret = 1;
        }
-       return pkt_err_flags;
+       *pkt_err_flags_out = pkt_err_flags;
+       return ret;
 }
 
 /*
@@ -282,6 +271,7 @@ enic_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
                dma_addr_t dma_addr;
                struct cq_desc cqd;
                uint64_t ol_err_flags;
+               uint8_t packet_error;
 
                /* Check for pkts available */
                color = (cqd_ptr->type_color >> CQ_DESC_COLOR_SHIFT)
@@ -303,9 +293,9 @@ enic_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
                        break;
                }
 
-               /* Check for FCS or packet errors */
-               ol_err_flags = enic_cq_rx_to_pkt_err_flags(&cqd);
-               if (ol_err_flags == 0)
+               /* A packet error means descriptor and data are untrusted */
+               packet_error = enic_cq_rx_to_pkt_err_flags(&cqd, &ol_err_flags);
+               if (!packet_error)
                        rx_pkt_len = enic_cq_rx_desc_n_bytes(&cqd);
                else
                        rx_pkt_len = 0;
@@ -340,10 +330,13 @@ enic_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
                rxmb->pkt_len = rx_pkt_len;
                rxmb->data_len = rx_pkt_len;
                rxmb->port = enic->port_id;
-               rxmb->packet_type = enic_cq_rx_flags_to_pkt_type(&cqd);
-               rxmb->ol_flags = ol_err_flags;
-               if (!ol_err_flags)
+               if (!packet_error) {
+                       rxmb->packet_type = enic_cq_rx_flags_to_pkt_type(&cqd);
                        enic_cq_rx_to_pkt_flags(&cqd, rxmb);
+               } else {
+                       rxmb->packet_type = 0;
+                       rxmb->ol_flags = 0;
+               }
 
                /* prefetch mbuf data for caller */
                rte_packet_prefetch(RTE_PTR_ADD(rxmb->buf_addr,