ibmvnic: Fixup atomic API usage

Replace a couple of modifications of an atomic followed
by a read of the atomic, which is no longer atomic, to
use atomic_XX_return variants to avoid race conditions.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index c10bae7823e05498d913bd473eea93537253f6f6..b5871dfff1b7f85300e8a0cbcd56ffcc9153fbfd 100644 (file)
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -962,9 +962,8 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
                goto out;
        }
 
-       atomic_inc(&tx_scrq->used);
-
-       if (atomic_read(&tx_scrq->used) >= adapter->req_tx_entries_per_subcrq) {
+       if (atomic_inc_return(&tx_scrq->used)
+                                       >= adapter->req_tx_entries_per_subcrq) {
                netdev_info(netdev, "Stopping queue %d\n", queue_num);
                netif_stop_subqueue(netdev, queue_num);
        }
@@ -1499,9 +1498,8 @@ restart_loop:
                        }
 
                        if (txbuff->last_frag) {
-                               atomic_dec(&scrq->used);
-
-                               if (atomic_read(&scrq->used) <=
+                               if (atomic_sub_return(next->tx_comp.num_comps,
+                                                     &scrq->used) <=
                                    (adapter->req_tx_entries_per_subcrq / 2) &&
                                    netif_subqueue_stopped(adapter->netdev,
                                                           txbuff->skb)) {