be2net: Handle out of buffer completions for lancer

If Lancer chip does not have posted RX buffers, it posts an RX completion entry
with the same frag_index as the last valid completion. The Error bit is also
set. In BE, a flush completion is indicated with a zero value for num_rcvd in
the completion.
Such completions don't carry any data and are not processed.
This patch refactors code to handle both cases with the same code.

Signed-off-by: Padmanabh Ratnakar <padmanabh.ratnakar@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 38 insertions, 21 deletions

diff --git a/drivers/net/benet/be.h b/drivers/net/benet/be.h
index b61a1dfebcaf..9cab32328bba 100644
--- a/drivers/net/benet/be.h
+++ b/drivers/net/benet/be.h
@@ -220,7 +220,9 @@ struct be_rx_obj {
         struct be_rx_stats stats;
         u8 rss_id;
         bool rx_post_starved;   /* Zero rx frags have been posted to BE */
-        u32 cache_line_barrier[16];
+        u16 last_frag_index;
+        u16 rsvd;
+        u32 cache_line_barrier[15];
 };
 
 struct be_vf_cfg {
diff --git a/drivers/net/benet/be_main.c b/drivers/net/benet/be_main.c
index ea8cf690a072..0b35e4a8bf19 100644
--- a/drivers/net/benet/be_main.c
+++ b/drivers/net/benet/be_main.c
@@ -911,11 +911,17 @@ static void be_rx_compl_discard(struct be_adapter *adapter,
         rxq_idx = AMAP_GET_BITS(struct amap_eth_rx_compl, fragndx, rxcp);
         num_rcvd = AMAP_GET_BITS(struct amap_eth_rx_compl, numfrags, rxcp);
 
-        for (i = 0; i < num_rcvd; i++) {
-                page_info = get_rx_page_info(adapter, rxo, rxq_idx);
-                put_page(page_info->page);
-                memset(page_info, 0, sizeof(*page_info));
-                index_inc(&rxq_idx, rxq->len);
+         /* Skip out-of-buffer compl(lancer) or flush compl(BE) */
+        if (likely(rxq_idx != rxo->last_frag_index && num_rcvd != 0)) {
+
+                rxo->last_frag_index = rxq_idx;
+
+                for (i = 0; i < num_rcvd; i++) {
+                        page_info = get_rx_page_info(adapter, rxo, rxq_idx);
+                        put_page(page_info->page);
+                        memset(page_info, 0, sizeof(*page_info));
+                        index_inc(&rxq_idx, rxq->len);
+                }
         }
 }
 
@@ -1016,9 +1022,6 @@ static void be_rx_compl_process(struct be_adapter *adapter,
         u8 vtm;
 
         num_rcvd = AMAP_GET_BITS(struct amap_eth_rx_compl, numfrags, rxcp);
-        /* Is it a flush compl that has no data */
-        if (unlikely(num_rcvd == 0))
-                return;
 
         skb = netdev_alloc_skb_ip_align(adapter->netdev, BE_HDR_LEN);
         if (unlikely(!skb)) {
@@ -1075,10 +1078,6 @@ static void be_rx_compl_process_gro(struct be_adapter *adapter,
         u8 pkt_type;
 
         num_rcvd = AMAP_GET_BITS(struct amap_eth_rx_compl, numfrags, rxcp);
-        /* Is it a flush compl that has no data */
-        if (unlikely(num_rcvd == 0))
-                return;
-
         pkt_size = AMAP_GET_BITS(struct amap_eth_rx_compl, pktsize, rxcp);
         vlanf = AMAP_GET_BITS(struct amap_eth_rx_compl, vtp, rxcp);
         rxq_idx = AMAP_GET_BITS(struct amap_eth_rx_compl, fragndx, rxcp);
@@ -1349,7 +1348,7 @@ static void be_rx_q_clean(struct be_adapter *adapter, struct be_rx_obj *rxo)
         while ((rxcp = be_rx_compl_get(rxo)) != NULL) {
                 be_rx_compl_discard(adapter, rxo, rxcp);
                 be_rx_compl_reset(rxcp);
-                be_cq_notify(adapter, rx_cq->id, true, 1);
+                be_cq_notify(adapter, rx_cq->id, false, 1);
         }
 
         /* Then free posted rx buffer that were not used */
@@ -1576,6 +1575,9 @@ static int be_rx_queues_create(struct be_adapter *adapter)
         adapter->big_page_size = (1 << get_order(rx_frag_size)) * PAGE_SIZE;
         for_all_rx_queues(adapter, rxo, i) {
                 rxo->adapter = adapter;
+                /* Init last_frag_index so that the frag index in the first
+                 * completion will never match */
+                rxo->last_frag_index = 0xffff;
                 rxo->rx_eq.max_eqd = BE_MAX_EQD;
                 rxo->rx_eq.enable_aic = true;
 
@@ -1697,10 +1699,9 @@ static irqreturn_t be_msix_tx_mcc(int irq, void *dev)
         return IRQ_HANDLED;
 }
 
-static inline bool do_gro(struct be_adapter *adapter, struct be_rx_obj *rxo,
-                        struct be_eth_rx_compl *rxcp)
+static inline bool do_gro(struct be_rx_obj *rxo,
+                        struct be_eth_rx_compl *rxcp, u8 err)
 {
-        int err = AMAP_GET_BITS(struct amap_eth_rx_compl, err, rxcp);
         int tcp_frame = AMAP_GET_BITS(struct amap_eth_rx_compl, tcpf, rxcp);
 
         if (err)
@@ -1717,6 +1718,8 @@ static int be_poll_rx(struct napi_struct *napi, int budget)
         struct be_queue_info *rx_cq = &rxo->cq;
         struct be_eth_rx_compl *rxcp;
         u32 work_done;
+        u16 frag_index, num_rcvd;
+        u8 err;
 
         rxo->stats.rx_polls++;
         for (work_done = 0; work_done < budget; work_done++) {
@@ -1724,10 +1727,22 @@ static int be_poll_rx(struct napi_struct *napi, int budget)
                 if (!rxcp)
                         break;
 
-                if (do_gro(adapter, rxo, rxcp))
-                        be_rx_compl_process_gro(adapter, rxo, rxcp);
-                else
-                        be_rx_compl_process(adapter, rxo, rxcp);
+                err = AMAP_GET_BITS(struct amap_eth_rx_compl, err, rxcp);
+                frag_index = AMAP_GET_BITS(struct amap_eth_rx_compl, fragndx,
+                                                                rxcp);
+                num_rcvd = AMAP_GET_BITS(struct amap_eth_rx_compl, numfrags,
+                                                                rxcp);
+
+                /* Skip out-of-buffer compl(lancer) or flush compl(BE) */
+                if (likely(frag_index != rxo->last_frag_index &&
+                                num_rcvd != 0)) {
+                        rxo->last_frag_index = frag_index;
+
+                        if (do_gro(rxo, rxcp, err))
+                                be_rx_compl_process_gro(adapter, rxo, rxcp);
+                        else
+                                be_rx_compl_process(adapter, rxo, rxcp);
+                }
 
                 be_rx_compl_reset(rxcp);
         }