i40evf: properly handle ndo_set_mac_address calls

The driver was not correctly handling calls to its ndo_set_mac_address
method. It did not properly check to see if the override would be
allowed by the PF driver, and never removed the old address from its
filter list.

Add a new flag to the adapter struct which is set if the MAC address is
assigned by the PF. Check this flag and don't allow the MAC address to
be changed if it is set. Search for and properly remove the filter
for the old MAC address when the new one is set.

Change-ID: I817bf620c869c5a80e6a7eab65c9cbad1dc89799
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40evf/i40evf.h

@@ -220,6 +220,7 @@ struct i40evf_adapter {
 #define I40EVF_FLAG_RESET_NEEDED                 BIT(10)
 #define I40EVF_FLAG_WB_ON_ITR_CAPABLE		BIT(11)
 #define I40EVF_FLAG_OUTER_UDP_CSUM_CAPABLE	BIT(12)
+#define I40EVF_FLAG_ADDR_SET_BY_PF		BIT(13)
 /* duplicates for common code */
 #define I40E_FLAG_FDIR_ATR_ENABLED		 0
 #define I40E_FLAG_DCB_ENABLED			 0

drivers/net/ethernet/intel/i40evf/i40evf_main.c

@@ -841,6 +841,15 @@ static int i40evf_set_mac(struct net_device *netdev, void *p)
 	if (ether_addr_equal(netdev->dev_addr, addr->sa_data))
 		return 0;
 
+	if (adapter->flags & I40EVF_FLAG_ADDR_SET_BY_PF)
+		return -EPERM;
+
+	f = i40evf_find_filter(adapter, hw->mac.addr);
+	if (f) {
+		f->remove = true;
+		adapter->aq_required |= I40EVF_FLAG_AQ_DEL_MAC_FILTER;
+	}
+
 	f = i40evf_add_filter(adapter, addr->sa_data);
 	if (f) {
 		ether_addr_copy(hw->mac.addr, addr->sa_data);
@@ -2244,10 +2253,13 @@ static void i40evf_init_task(struct work_struct *work)
 	if (!is_valid_ether_addr(adapter->hw.mac.addr)) {
 		dev_info(&pdev->dev, "Invalid MAC address %pM, using random\n",
 			 adapter->hw.mac.addr);
-		random_ether_addr(adapter->hw.mac.addr);
-	}
+		eth_hw_addr_random(netdev);
+		ether_addr_copy(adapter->hw.mac.addr, netdev->dev_addr);
+	} else {
+		adapter->flags |= I40EVF_FLAG_ADDR_SET_BY_PF;
 		ether_addr_copy(netdev->dev_addr, adapter->hw.mac.addr);
 		ether_addr_copy(netdev->perm_addr, adapter->hw.mac.addr);
+	}
 
 	init_timer(&adapter->watchdog_timer);
 	adapter->watchdog_timer.function = &i40evf_watchdog_timer;