igb: avoid unnecessary conversions from u16 to int

There are a number of places where we have values that are stored as u16
but are being converted to int unnecessarily.  In order to avoid that we
should convert all variables that deal with the next_to_clean, next_to_use,
and count to u16 values.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by:  Aaron Brown  <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igb/igb_ethtool.c

@@ -1581,8 +1581,8 @@ static int igb_clean_test_rings(struct igb_ring *rx_ring,
 	union e1000_adv_rx_desc *rx_desc;
 	struct igb_rx_buffer *rx_buffer_info;
 	struct igb_tx_buffer *tx_buffer_info;
-	int rx_ntc, tx_ntc, count = 0;
 	u32 staterr;
+	u16 rx_ntc, tx_ntc, count = 0;
 
 	/* initialize next to clean and descriptor values */
 	rx_ntc = rx_ring->next_to_clean;
@@ -1634,7 +1634,8 @@ static int igb_run_loopback_test(struct igb_adapter *adapter)
 {
 	struct igb_ring *tx_ring = &adapter->test_tx_ring;
 	struct igb_ring *rx_ring = &adapter->test_rx_ring;
-	int i, j, lc, good_cnt, ret_val = 0;
+	u16 i, j, lc, good_cnt;
+	int ret_val = 0;
 	unsigned int size = IGB_RX_HDR_LEN;
 	netdev_tx_t tx_ret_val;
 	struct sk_buff *skb;

drivers/net/ethernet/intel/igb/igb_main.c

@@ -338,14 +338,13 @@ static void igb_dump(struct igb_adapter *adapter)
 	struct net_device *netdev = adapter->netdev;
 	struct e1000_hw *hw = &adapter->hw;
 	struct igb_reg_info *reginfo;
-	int n = 0;
 	struct igb_ring *tx_ring;
 	union e1000_adv_tx_desc *tx_desc;
 	struct my_u0 { u64 a; u64 b; } *u0;
 	struct igb_ring *rx_ring;
 	union e1000_adv_rx_desc *rx_desc;
 	u32 staterr;
-	int i = 0;
+	u16 i, n;
 
 	if (!netif_msg_hw(adapter))
 		return;
@@ -3239,7 +3238,7 @@ static void igb_clean_tx_ring(struct igb_ring *tx_ring)
 {
 	struct igb_tx_buffer *buffer_info;
 	unsigned long size;
-	unsigned int i;
+	u16 i;
 
 	if (!tx_ring->tx_buffer_info)
 		return;
@@ -4355,7 +4354,7 @@ static void igb_tx_map(struct igb_ring *tx_ring,
 	tx_ring->next_to_use = i;
 }
 
-static int __igb_maybe_stop_tx(struct igb_ring *tx_ring, int size)
+static int __igb_maybe_stop_tx(struct igb_ring *tx_ring, const u16 size)
 {
 	struct net_device *netdev = tx_ring->netdev;
 
@@ -4381,7 +4380,7 @@ static int __igb_maybe_stop_tx(struct igb_ring *tx_ring, int size)
 	return 0;
 }
 
-static inline int igb_maybe_stop_tx(struct igb_ring *tx_ring, int size)
+static inline int igb_maybe_stop_tx(struct igb_ring *tx_ring, const u16 size)
 {
 	if (igb_desc_unused(tx_ring) >= size)
 		return 0;