[PATCH net-next] ibmvnic: Fixup atomic API usage
From: Nathan Fontenot <hidden>
Date: 2017-04-14 13:00:01
Subsystem:
ibm power sriov virtual nic device driver, linux for powerpc (32-bit and 64-bit), networking drivers, the rest · Maintainers:
Haren Myneni, Rick Lindsley, Madhavan Srinivasan, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Brian King <redacted> 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 <redacted> Signed-off-by: Nathan Fontenot <redacted> --- drivers/net/ethernet/ibm/ibmvnic.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index c10bae7..b5871df 100644
--- 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 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter, } 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)) {