ixgb: eliminate checkstack warnings

Really trivial fix, use kmalloc/kfree instead of stack space.
use static const instead of const to further reduce stack usage.

V2: reflect changes suggested by Joe Perches

before:
[jbrandeb@jbrandeb-mobl2 linux-2.6]$ make checkstack|grep '\[ixgb\]'
0x00000fc1 ixgb_set_multi [ixgb]:                       768
0x00001031 ixgb_set_multi [ixgb]:                       768
0x000010f2 ixgb_set_multi [ixgb]:                       768
0x061c ixgb_check_options [ixgb]:                       448
0x09c3 ixgb_check_options [ixgb]:                       448
0x0000649e ixgb_set_ringparam [ixgb]:                   192
0x0000130d ixgb_xmit_frame [ixgb]:                      184
0x000019e0 ixgb_xmit_frame [ixgb]:                      184
0x00002267 ixgb_clean [ixgb]:                           152
0x00002673 ixgb_clean [ixgb]:                           152

after:
0x000064ee ixgb_set_ringparam [ixgb]:                   192
0x0000135d ixgb_xmit_frame [ixgb]:                      184
0x00001a30 ixgb_xmit_frame [ixgb]:                      184
0x000022b7 ixgb_clean [ixgb]:                           152
0x000026c3 ixgb_clean [ixgb]:                           152

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 7 deletions

diff --git a/drivers/net/ethernet/intel/ixgb/ixgb_main.c b/drivers/net/ethernet/intel/ixgb/ixgb_main.c
index b8fb16304598..ca3ab4a29ac4 100644
--- a/drivers/net/ethernet/intel/ixgb/ixgb_main.c
+++ b/drivers/net/ethernet/intel/ixgb/ixgb_main.c
@@ -1093,7 +1093,6 @@ ixgb_set_multi(struct net_device *netdev)
         struct ixgb_hw *hw = &adapter->hw;
         struct netdev_hw_addr *ha;
         u32 rctl;
-        int i;
 
         /* Check for Promiscuous and All Multicast modes */
 
@@ -1120,19 +1119,27 @@ ixgb_set_multi(struct net_device *netdev)
                 rctl |= IXGB_RCTL_MPE;
                 IXGB_WRITE_REG(hw, RCTL, rctl);
         } else {
-                u8 mta[IXGB_MAX_NUM_MULTICAST_ADDRESSES *
-                            IXGB_ETH_LENGTH_OF_ADDRESS];
+                u8 *mta = kmalloc(IXGB_MAX_NUM_MULTICAST_ADDRESSES *
+                              ETH_ALEN, GFP_ATOMIC);
+                u8 *addr;
+                if (!mta) {
+                        pr_err("allocation of multicast memory failed\n");
+                        goto alloc_failed;
+                }
 
                 IXGB_WRITE_REG(hw, RCTL, rctl);
 
-                i = 0;
-                netdev_for_each_mc_addr(ha, netdev)
-                        memcpy(&mta[i++ * IXGB_ETH_LENGTH_OF_ADDRESS],
-                               ha->addr, IXGB_ETH_LENGTH_OF_ADDRESS);
+                addr = mta;
+                netdev_for_each_mc_addr(ha, netdev) {
+                        memcpy(addr, ha->addr, ETH_ALEN);
+                        addr += ETH_ALEN;
+                }
 
                 ixgb_mc_addr_list_update(hw, mta, netdev_mc_count(netdev), 0);
+                kfree(mta);
         }
 
+alloc_failed:
         if (netdev->features & NETIF_F_HW_VLAN_RX)
                 ixgb_vlan_strip_enable(adapter);
         else