igc: Refactor igc_mac_entry_can_be_used()

The helper igc_mac_entry_can_be_used() implementation is a bit
convoluted since it does two different things: find a not-in-use slot
in mac_table or find an in-use slot where the address and address type
match. This patch does a code refactoring and break it up into two
helper functions.

With this patch we might traverse mac_table twice in some situations,
but this is not harmful performance-wise (mac_table has only 16 entries
and adding mac filters is not hot-path), and it improves igc_add_mac_
filter() readability considerably.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 3af6ce1712d5613cee0955e28759b65e1aace529..79a9875e07672ceabb780bcc4fae39e393990692 100644 (file)
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -2176,25 +2176,44 @@ static void igc_nfc_filter_restore(struct igc_adapter *adapter)
        spin_unlock(&adapter->nfc_lock);
 }
 
-/* If the filter to be added and an already existing filter express
- * the same address and address type, it should be possible to only
- * override the other configurations, for example the queue to steer
- * traffic.
- */
-static bool igc_mac_entry_can_be_used(const struct igc_mac_addr *entry,
-                                     const u8 *addr, const u8 flags)
+static int igc_find_mac_filter(struct igc_adapter *adapter, const u8 *addr,
+                              u8 flags)
 {
-       if (!(entry->state & IGC_MAC_STATE_IN_USE))
-               return true;
+       int max_entries = adapter->hw.mac.rar_entry_count;
+       struct igc_mac_addr *entry;
+       int i;
 
-       if ((entry->state & IGC_MAC_STATE_SRC_ADDR) !=
-           (flags & IGC_MAC_STATE_SRC_ADDR))
-               return false;
+       for (i = 0; i < max_entries; i++) {
+               entry = &adapter->mac_table[i];
 
-       if (!ether_addr_equal(addr, entry->addr))
-               return false;
+               if (!(entry->state & IGC_MAC_STATE_IN_USE))
+                       continue;
+               if (!ether_addr_equal(addr, entry->addr))
+                       continue;
+               if ((entry->state & IGC_MAC_STATE_SRC_ADDR) !=
+                   (flags & IGC_MAC_STATE_SRC_ADDR))
+                       continue;
 
-       return true;
+               return i;
+       }
+
+       return -1;
+}
+
+static int igc_get_avail_mac_filter_slot(struct igc_adapter *adapter)
+{
+       int max_entries = adapter->hw.mac.rar_entry_count;
+       struct igc_mac_addr *entry;
+       int i;
+
+       for (i = 0; i < max_entries; i++) {
+               entry = &adapter->mac_table[i];
+
+               if (!(entry->state & IGC_MAC_STATE_IN_USE))
+                       return i;
+       }
+
+       return -1;
 }
 
 /**
@@ -2212,33 +2231,28 @@ static bool igc_mac_entry_can_be_used(const struct igc_mac_addr *entry,
 int igc_add_mac_filter(struct igc_adapter *adapter, const u8 *addr,
                       const s8 queue, const u8 flags)
 {
-       struct igc_hw *hw = &adapter->hw;
-       int rar_entries = hw->mac.rar_entry_count;
-       int i;
+       int index;
 
        if (!is_valid_ether_addr(addr))
                return -EINVAL;
        if (flags & IGC_MAC_STATE_SRC_ADDR)
                return -ENOTSUPP;
 
-       /* Search for the first empty entry in the MAC table.
-        * Do not touch entries at the end of the table reserved for the VF MAC
-        * addresses.
-        */
-       for (i = 0; i < rar_entries; i++) {
-               if (!igc_mac_entry_can_be_used(&adapter->mac_table[i],
-                                              addr, flags))
-                       continue;
+       index = igc_find_mac_filter(adapter, addr, flags);
+       if (index >= 0)
+               goto update_queue_assignment;
 
-               ether_addr_copy(adapter->mac_table[i].addr, addr);
-               adapter->mac_table[i].queue = queue;
-               adapter->mac_table[i].state |= IGC_MAC_STATE_IN_USE | flags;
+       index = igc_get_avail_mac_filter_slot(adapter);
+       if (index < 0)
+               return -ENOSPC;
 
-               igc_set_mac_filter_hw(adapter, i, addr, queue);
-               return 0;
-       }
+       ether_addr_copy(adapter->mac_table[index].addr, addr);
+       adapter->mac_table[index].state |= IGC_MAC_STATE_IN_USE | flags;
+update_queue_assignment:
+       adapter->mac_table[index].queue = queue;
 
-       return -ENOSPC;
+       igc_set_mac_filter_hw(adapter, index, addr, queue);
+       return 0;
 }
 
 /**