sky2: Refactor sky2_get_regs into two functions

Separate code deciding which registers can be accessed out of
sky2_get_regs in preparation for adding more conditions into it.
Signed-off-by: Mike McCormack <mikem@ring3k.org>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/sky2.c

@@ -3837,33 +3837,14 @@ static int sky2_get_regs_len(struct net_device *dev)
 	return 0x4000;
 }
 
-/*
- * Returns copy of control register region
- * Note: ethtool_get_regs always provides full size (16k) buffer
- */
-static void sky2_get_regs(struct net_device *dev, struct ethtool_regs *regs,
-			  void *p)
+static int sky2_reg_access_ok(struct sky2_hw *hw, unsigned int b)
 {
-	const struct sky2_port *sky2 = netdev_priv(dev);
-	const void __iomem *io = sky2->hw->regs;
-	unsigned int b;
-
-	regs->version = 1;
-
-	for (b = 0; b < 128; b++) {
 	/* This complicated switch statement is to make sure and
 	 * only access regions that are unreserved.
 	 * Some blocks are only valid on dual port cards.
-		 * and block 3 has some special diagnostic registers that
-		 * are poison.
 	 */
 	switch (b) {
-		case 3:
-			/* skip diagnostic ram region */
-			memcpy_fromio(p + 0x10, io + 0x10, 128 - 0x10);
-			break;
-
-		/* dual port cards only */
+	/* second port */
 	case 5:		/* Tx Arbiter 2 */
 	case 9:		/* RX2 */
 	case 14 ... 15:	/* TX2 */
@@ -3875,9 +3856,8 @@ static void sky2_get_regs(struct net_device *dev, struct ethtool_regs *regs,
 	case 40 ... 47: /* Pattern Ram 2 */
 	case 52: case 54: /* TCP Segmentation 2 */
 	case 112 ... 116: /* GMAC 2 */
-			if (sky2->hw->ports == 1)
-				goto reserved;
-			/* fall through */
+		return hw->ports > 1;
+
 	case 0:		/* Control */
 	case 2:		/* Mac address */
 	case 4:		/* Tx Arbiter 1 */
@@ -3894,12 +3874,34 @@ static void sky2_get_regs(struct net_device *dev, struct ethtool_regs *regs,
 	case 48: case 50: /* TCP Segmentation 1 */
 	case 56 ... 60:	/* PCI space */
 	case 80 ... 84:	/* GMAC 1 */
-			memcpy_fromio(p, io, 128);
-			break;
+		return 1;
+
 	default:
-reserved:
-			memset(p, 0, 128);
+		return 0;
 	}
+}
+
+/*
+ * Returns copy of control register region
+ * Note: ethtool_get_regs always provides full size (16k) buffer
+ */
+static void sky2_get_regs(struct net_device *dev, struct ethtool_regs *regs,
+			  void *p)
+{
+	const struct sky2_port *sky2 = netdev_priv(dev);
+	const void __iomem *io = sky2->hw->regs;
+	unsigned int b;
+
+	regs->version = 1;
+
+	for (b = 0; b < 128; b++) {
+		/* skip poisonous diagnostic ram region in block 3 */
+		if (b == 3)
+			memcpy_fromio(p + 0x10, io + 0x10, 128 - 0x10);
+		else if (sky2_reg_access_ok(sky2->hw, b))
+			memcpy_fromio(p, io, 128);
+		else
+			memset(p, 0, 128);
 
 		p += 128;
 		io += 128;