sh_eth: use DMA barriers

Commit  7d7355f58ba4 ("sh_eth: Ensure proper ordering of descriptor active
bit write/read") did the right thing  but used too "heavy" barriers while
there were already "lighter" DMA barriers exactly  for this case...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index dc5d34e1d01e3754a44bb58a8ff8819d3f79d4e0..6150a235b72ccaf8bf58dd862362b02fe7f0cfae 100644 (file)
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1416,7 +1416,7 @@ static int sh_eth_txfree(struct net_device *ndev)
                if (txdesc->status & cpu_to_edmac(mdp, TD_TACT))
                        break;
                /* TACT bit must be checked before all the following reads */
                if (txdesc->status & cpu_to_edmac(mdp, TD_TACT))
                        break;
                /* TACT bit must be checked before all the following reads */

-               rmb();
+               dma_rmb();

                netif_info(mdp, tx_done, ndev,
                           "tx entry %d status 0x%08x\n",
                           entry, edmac_to_cpu(mdp, txdesc->status));
                netif_info(mdp, tx_done, ndev,
                           "tx entry %d status 0x%08x\n",
                           entry, edmac_to_cpu(mdp, txdesc->status));


@@ -1458,7 +1458,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
        rxdesc = &mdp->rx_ring[entry];
        while (!(rxdesc->status & cpu_to_edmac(mdp, RD_RACT))) {
                /* RACT bit must be checked before all the following reads */
        rxdesc = &mdp->rx_ring[entry];
        while (!(rxdesc->status & cpu_to_edmac(mdp, RD_RACT))) {
                /* RACT bit must be checked before all the following reads */

-               rmb();
+               dma_rmb();

                desc_status = edmac_to_cpu(mdp, rxdesc->status);
                pkt_len = rxdesc->frame_length;
 
                desc_status = edmac_to_cpu(mdp, rxdesc->status);
                pkt_len = rxdesc->frame_length;
 


@@ -1544,7 +1544,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
                        skb_checksum_none_assert(skb);
                        rxdesc->addr = dma_addr;
                }
                        skb_checksum_none_assert(skb);
                        rxdesc->addr = dma_addr;
                }

-               wmb(); /* RACT bit must be set after all the above writes */
+               dma_wmb(); /* RACT bit must be set after all the above writes */

                if (entry >= mdp->num_rx_ring - 1)
                        rxdesc->status |=
                                cpu_to_edmac(mdp, RD_RACT | RD_RFP | RD_RDLE);
                if (entry >= mdp->num_rx_ring - 1)
                        rxdesc->status |=
                                cpu_to_edmac(mdp, RD_RACT | RD_RFP | RD_RDLE);


@@ -2403,7 +2403,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
        }
        txdesc->buffer_length = skb->len;
 
        }
        txdesc->buffer_length = skb->len;
 

-       wmb(); /* TACT bit must be set after all the above writes */
+       dma_wmb(); /* TACT bit must be set after all the above writes */

        if (entry >= mdp->num_tx_ring - 1)
                txdesc->status |= cpu_to_edmac(mdp, TD_TACT | TD_TDLE);
        else
        if (entry >= mdp->num_tx_ring - 1)
                txdesc->status |= cpu_to_edmac(mdp, TD_TACT | TD_TDLE);
        else