net: xilinx_emacps: Apply the spinlock to the required critical section

Applied the spinlock to the required critical sections in xemacps_tx_poll
and xemacps_start_xmit function. Removed the barrier instructions that exist
just before the spinlock calls and the places where the usage of barrier
instrcution is not relevant.

Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/net/ethernet/xilinx/xilinx_emacps.c b/drivers/net/ethernet/xilinx/xilinx_emacps.c
index 9e69322761f465beb54992cd46e2b2ead47dfd40..3f526599a5372943eb680632dc46151e5253e646 100644 (file)
--- a/drivers/net/ethernet/xilinx/xilinx_emacps.c
+++ b/drivers/net/ethernet/xilinx/xilinx_emacps.c
@@ -1235,8 +1235,8 @@ static void xemacps_tx_poll(unsigned long data)
        struct ring_info *rp;
        struct sk_buff *skb;
        unsigned long flags;
+       unsigned int txbdcount;
 
-       spin_lock(&lp->tx_lock);
        regval = xemacps_read(lp->baseaddr, XEMACPS_TXSR_OFFSET);
        xemacps_write(lp->baseaddr, XEMACPS_TXSR_OFFSET, regval);
        dev_dbg(&lp->pdev->dev, "TX status 0x%x\n", regval);
@@ -1271,10 +1271,10 @@ static void xemacps_tx_poll(unsigned long data)
                cur_p = &lp->tx_bd[cur_i];
        }
        numbdstofree = bdcount - bdpartialcount;
-       lp->tx_bd_freecnt += numbdstofree;
+       txbdcount = numbdstofree;
        numbdsinhw -= numbdstofree;
        if (!numbdstofree)
-               goto tx_poll_out;
+               return;
 
        cur_p = &lp->tx_bd[lp->tx_bd_ci];
        while (numbdstofree) {
@@ -1325,7 +1325,10 @@ static void xemacps_tx_poll(unsigned long data)
                cur_p = &lp->tx_bd[lp->tx_bd_ci];
                numbdstofree--;
        }
-       wmb();
+
+       spin_lock(&lp->tx_lock);
+       lp->tx_bd_freecnt += txbdcount;
+       spin_unlock(&lp->tx_lock);
 
        if (numbdsinhw) {
                spin_lock_irqsave(&lp->nwctrlreg_lock, flags);
@@ -1336,9 +1339,6 @@ static void xemacps_tx_poll(unsigned long data)
        }
 
        netif_wake_queue(ndev);
-
-tx_poll_out:
-       spin_unlock(&lp->tx_lock);
 }
 
 /**
@@ -2019,23 +2019,18 @@ static int xemacps_start_xmit(struct sk_buff *skb, struct net_device *ndev)
        u32 bd_tail;
 
        nr_frags = skb_shinfo(skb)->nr_frags + 1;
-       spin_lock_bh(&lp->tx_lock);
-
        if (nr_frags > lp->tx_bd_freecnt) {
                netif_stop_queue(ndev); /* stop send queue */
-               spin_unlock_bh(&lp->tx_lock);
                return NETDEV_TX_BUSY;
        }
 
        if (xemacps_clear_csum(skb, ndev)) {
-               spin_unlock_bh(&lp->tx_lock);
                kfree(skb);
                return NETDEV_TX_OK;
        }
 
        bd_tail = lp->tx_bd_tail;
        cur_p = &lp->tx_bd[bd_tail];
-       lp->tx_bd_freecnt -= nr_frags;
        frag = &skb_shinfo(skb)->frags[0];
 
        for (i = 0; i < nr_frags; i++) {
@@ -2074,7 +2069,6 @@ static int xemacps_start_xmit(struct sk_buff *skb, struct net_device *ndev)
                lp->tx_bd_tail = lp->tx_bd_tail % XEMACPS_SEND_BD_CNT;
                cur_p = &(lp->tx_bd[lp->tx_bd_tail]);
        }
-       wmb();
 
        /* commit first buffer to hardware -- do this after
         * committing the other buffers to avoid an underrun */
@@ -2082,7 +2076,10 @@ static int xemacps_start_xmit(struct sk_buff *skb, struct net_device *ndev)
        regval = cur_p->ctrl;
        regval &= ~XEMACPS_TXBUF_USED_MASK;
        cur_p->ctrl = regval;
-       wmb();
+
+       spin_lock_bh(&lp->tx_lock);
+       lp->tx_bd_freecnt -= nr_frags;
+       spin_unlock_bh(&lp->tx_lock);
 
        spin_lock_irqsave(&lp->nwctrlreg_lock, flags);
        regval = xemacps_read(lp->baseaddr, XEMACPS_NWCTRL_OFFSET);
@@ -2090,7 +2087,6 @@ static int xemacps_start_xmit(struct sk_buff *skb, struct net_device *ndev)
                        (regval | XEMACPS_NWCTRL_STARTTX_MASK));
        spin_unlock_irqrestore(&lp->nwctrlreg_lock, flags);
 
-       spin_unlock_bh(&lp->tx_lock);
        ndev->trans_start = jiffies;
        return 0;
 }