via-rhine: add consistent memory barrier in vlan receive code.

The NAPI receive path depends on desc->rx_status but it does not
enforce any explicit receive barrier.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/via/via-rhine.c b/drivers/net/ethernet/via/via-rhine.c
index fede9fc..8195fcd 100644 (file)
--- a/drivers/net/ethernet/via/via-rhine.c
+++ b/drivers/net/ethernet/via/via-rhine.c
@@ -1993,6 +1993,18 @@ static inline u16 rhine_get_vlan_tci(struct sk_buff *skb, int data_size)
        return be16_to_cpup((__be16 *)trailer);
 }
 
+static inline void rhine_rx_vlan_tag(struct sk_buff *skb, struct rx_desc *desc,
+                                    int data_size)
+{
+       dma_rmb();
+       if (unlikely(desc->desc_length & cpu_to_le32(DescTag))) {
+               u16 vlan_tci;
+
+               vlan_tci = rhine_get_vlan_tci(skb, data_size);
+               __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tci);
+       }
+}
+
 /* Process up to limit frames from receive ring */
 static int rhine_rx(struct net_device *dev, int limit)
 {
@@ -2008,7 +2020,6 @@ static int rhine_rx(struct net_device *dev, int limit)
        for (count = 0; count < limit; ++count) {
                struct rx_desc *desc = rp->rx_ring + entry;
                u32 desc_status = le32_to_cpu(desc->rx_status);
-               u32 desc_length = le32_to_cpu(desc->desc_length);
                int data_size = desc_status >> 16;
 
                if (desc_status & DescOwn)
@@ -2048,7 +2059,6 @@ static int rhine_rx(struct net_device *dev, int limit)
                        /* Length should omit the CRC */
                        int pkt_len = data_size - 4;
                        struct sk_buff *skb;
-                       u16 vlan_tci = 0;
 
                        /* Check if the packet is long enough to accept without
                           copying to a minimally-sized skbuff. */
@@ -2086,14 +2096,10 @@ static int rhine_rx(struct net_device *dev, int limit)
                        }
 
                        skb_put(skb, pkt_len);
-
-                       if (unlikely(desc_length & DescTag))
-                               vlan_tci = rhine_get_vlan_tci(skb, data_size);
-
                        skb->protocol = eth_type_trans(skb, dev);
 
-                       if (unlikely(desc_length & DescTag))
-                               __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tci);
+                       rhine_rx_vlan_tag(skb, desc, data_size);
+
                        netif_receive_skb(skb);
 
                        u64_stats_update_begin(&rp->rx_stats.syncp);