1 files changed, 45 insertions, 16 deletions

diff --git a/drivers/net/niu.c b/drivers/net/niu.c
index 2541321bad82..9fb59d3f9c92 100644
--- a/drivers/net/niu.c
+++ b/drivers/net/niu.c
@@ -4489,6 +4489,9 @@ static int niu_alloc_channels(struct niu *np)
 {
         struct niu_parent *parent = np->parent;
         int first_rx_channel, first_tx_channel;
+        int num_rx_rings, num_tx_rings;
+        struct rx_ring_info *rx_rings;
+        struct tx_ring_info *tx_rings;
         int i, port, err;
 
         port = np->port;
@@ -4498,18 +4501,21 @@ static int niu_alloc_channels(struct niu *np)
                 first_tx_channel += parent->txchan_per_port[i];
         }
 
-        np->num_rx_rings = parent->rxchan_per_port[port];
-        np->num_tx_rings = parent->txchan_per_port[port];
+        num_rx_rings = parent->rxchan_per_port[port];
+        num_tx_rings = parent->txchan_per_port[port];
 
-        netif_set_real_num_rx_queues(np->dev, np->num_rx_rings);
-        netif_set_real_num_tx_queues(np->dev, np->num_tx_rings);
-
-        np->rx_rings = kcalloc(np->num_rx_rings, sizeof(struct rx_ring_info),
-                               GFP_KERNEL);
+        rx_rings = kcalloc(num_rx_rings, sizeof(struct rx_ring_info),
+                           GFP_KERNEL);
         err = -ENOMEM;
-        if (!np->rx_rings)
+        if (!rx_rings)
                 goto out_err;
 
+        np->num_rx_rings = num_rx_rings;
+        smp_wmb();
+        np->rx_rings = rx_rings;
+
+        netif_set_real_num_rx_queues(np->dev, num_rx_rings);
+
         for (i = 0; i < np->num_rx_rings; i++) {
                 struct rx_ring_info *rp = &np->rx_rings[i];
 
@@ -4538,12 +4544,18 @@ static int niu_alloc_channels(struct niu *np)
                         return err;
         }
 
-        np->tx_rings = kcalloc(np->num_tx_rings, sizeof(struct tx_ring_info),
-                               GFP_KERNEL);
+        tx_rings = kcalloc(num_tx_rings, sizeof(struct tx_ring_info),
+                           GFP_KERNEL);
         err = -ENOMEM;
-        if (!np->tx_rings)
+        if (!tx_rings)
                 goto out_err;
 
+        np->num_tx_rings = num_tx_rings;
+        smp_wmb();
+        np->tx_rings = tx_rings;
+
+        netif_set_real_num_tx_queues(np->dev, num_tx_rings);
+
         for (i = 0; i < np->num_tx_rings; i++) {
                 struct tx_ring_info *rp = &np->tx_rings[i];
 
@@ -6246,11 +6258,17 @@ static void niu_sync_mac_stats(struct niu *np)
 static void niu_get_rx_stats(struct niu *np)
 {
         unsigned long pkts, dropped, errors, bytes;
+        struct rx_ring_info *rx_rings;
         int i;
 
         pkts = dropped = errors = bytes = 0;
+
+        rx_rings = ACCESS_ONCE(np->rx_rings);
+        if (!rx_rings)
+                goto no_rings;
+
         for (i = 0; i < np->num_rx_rings; i++) {
-                struct rx_ring_info *rp = &np->rx_rings[i];
+                struct rx_ring_info *rp = &rx_rings[i];
 
                 niu_sync_rx_discard_stats(np, rp, 0);
 
@@ -6259,6 +6277,8 @@ static void niu_get_rx_stats(struct niu *np)
                 dropped += rp->rx_dropped;
                 errors += rp->rx_errors;
         }
+
+no_rings:
         np->dev->stats.rx_packets = pkts;
         np->dev->stats.rx_bytes = bytes;
         np->dev->stats.rx_dropped = dropped;
@@ -6268,16 +6288,24 @@ static void niu_get_rx_stats(struct niu *np)
 static void niu_get_tx_stats(struct niu *np)
 {
         unsigned long pkts, errors, bytes;
+        struct tx_ring_info *tx_rings;
         int i;
 
         pkts = errors = bytes = 0;
+
+        tx_rings = ACCESS_ONCE(np->tx_rings);
+        if (!tx_rings)
+                goto no_rings;
+
         for (i = 0; i < np->num_tx_rings; i++) {
-                struct tx_ring_info *rp = &np->tx_rings[i];
+                struct tx_ring_info *rp = &tx_rings[i];
 
                 pkts += rp->tx_packets;
                 bytes += rp->tx_bytes;
                 errors += rp->tx_errors;
         }
+
+no_rings:
         np->dev->stats.tx_packets = pkts;
         np->dev->stats.tx_bytes = bytes;
         np->dev->stats.tx_errors = errors;
@@ -6287,9 +6315,10 @@ static struct net_device_stats *niu_get_stats(struct net_device *dev)
 {
         struct niu *np = netdev_priv(dev);
 
-        niu_get_rx_stats(np);
-        niu_get_tx_stats(np);
-
+        if (netif_running(dev)) {
+                niu_get_rx_stats(np);
+                niu_get_tx_stats(np);
+        }
         return &dev->stats;
 }