net: Refactor full duplex flow control resolution

These 4 drivers have identical full duplex flow control resolution
functions.  This patch changes them all to use one common function.

The function in question decides whether a device should enable TX and
RX flow control in a standard way (IEEE 802.3-2005 table 28B-3), so this
should also be useful for other drivers.
Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/smsc911x.c

@@ -642,28 +642,6 @@ static int smsc911x_phy_loopbacktest(struct net_device *dev)
 }
 #endif				/* USE_PHY_WORK_AROUND */
 
-static u8 smsc95xx_resolve_flowctrl_fulldplx(u16 lcladv, u16 rmtadv)
-{
-	u8 cap = 0;
-
-	if (lcladv & ADVERTISE_PAUSE_CAP) {
-		if (lcladv & ADVERTISE_PAUSE_ASYM) {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
-			else if (rmtadv & LPA_PAUSE_ASYM)
-				cap = FLOW_CTRL_RX;
-		} else {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
-		}
-	} else if (lcladv & ADVERTISE_PAUSE_ASYM) {
-		if ((rmtadv & LPA_PAUSE_CAP) && (rmtadv & LPA_PAUSE_ASYM))
-			cap = FLOW_CTRL_TX;
-	}
-
-	return cap;
-}
-
 static void smsc911x_phy_update_flowcontrol(struct smsc911x_data *pdata)
 {
 	struct phy_device *phy_dev = pdata->phy_dev;
@@ -674,7 +652,7 @@ static void smsc911x_phy_update_flowcontrol(struct smsc911x_data *pdata)
 	if (phy_dev->duplex == DUPLEX_FULL) {
 		u16 lcladv = phy_read(phy_dev, MII_ADVERTISE);
 		u16 rmtadv = phy_read(phy_dev, MII_LPA);
-		u8 cap = smsc95xx_resolve_flowctrl_fulldplx(lcladv, rmtadv);
+		u8 cap = mii_resolve_flowctrl_fdx(lcladv, rmtadv);
 
 		if (cap & FLOW_CTRL_RX)
 			flow = 0xFFFF0002;

drivers/net/smsc9420.c

@@ -1080,28 +1080,6 @@ static void smsc9420_set_multicast_list(struct net_device *dev)
 	smsc9420_pci_flush_write(pd);
 }
 
-static u8 smsc9420_resolve_flowctrl_fulldplx(u16 lcladv, u16 rmtadv)
-{
-	u8 cap = 0;
-
-	if (lcladv & ADVERTISE_PAUSE_CAP) {
-		if (lcladv & ADVERTISE_PAUSE_ASYM) {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
-			else if (rmtadv & LPA_PAUSE_ASYM)
-				cap = FLOW_CTRL_RX;
-		} else {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
-		}
-	} else if (lcladv & ADVERTISE_PAUSE_ASYM) {
-		if ((rmtadv & LPA_PAUSE_CAP) && (rmtadv & LPA_PAUSE_ASYM))
-			cap = FLOW_CTRL_TX;
-	}
-
-	return cap;
-}
-
 static void smsc9420_phy_update_flowcontrol(struct smsc9420_pdata *pd)
 {
 	struct phy_device *phy_dev = pd->phy_dev;
@@ -1110,7 +1088,7 @@ static void smsc9420_phy_update_flowcontrol(struct smsc9420_pdata *pd)
 	if (phy_dev->duplex == DUPLEX_FULL) {
 		u16 lcladv = phy_read(phy_dev, MII_ADVERTISE);
 		u16 rmtadv = phy_read(phy_dev, MII_LPA);
-		u8 cap = smsc9420_resolve_flowctrl_fulldplx(lcladv, rmtadv);
+		u8 cap = mii_resolve_flowctrl_fdx(lcladv, rmtadv);
 
 		if (cap & FLOW_CTRL_RX)
 			flow = 0xFFFF0002;

drivers/net/tg3.c

@@ -1227,28 +1227,6 @@ static u16 tg3_advert_flowctrl_1000X(u8 flow_ctrl)
 	return miireg;
 }
 
-static u8 tg3_resolve_flowctrl_1000T(u16 lcladv, u16 rmtadv)
-{
-	u8 cap = 0;
-
-	if (lcladv & ADVERTISE_PAUSE_CAP) {
-		if (lcladv & ADVERTISE_PAUSE_ASYM) {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = TG3_FLOW_CTRL_TX | TG3_FLOW_CTRL_RX;
-			else if (rmtadv & LPA_PAUSE_ASYM)
-				cap = TG3_FLOW_CTRL_RX;
-		} else {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = TG3_FLOW_CTRL_TX | TG3_FLOW_CTRL_RX;
-		}
-	} else if (lcladv & ADVERTISE_PAUSE_ASYM) {
-		if ((rmtadv & LPA_PAUSE_CAP) && (rmtadv & LPA_PAUSE_ASYM))
-			cap = TG3_FLOW_CTRL_TX;
-	}
-
-	return cap;
-}
-
 static u8 tg3_resolve_flowctrl_1000X(u16 lcladv, u16 rmtadv)
 {
 	u8 cap = 0;
@@ -1288,7 +1266,7 @@ static void tg3_setup_flow_control(struct tg3 *tp, u32 lcladv, u32 rmtadv)
 		if (tp->tg3_flags2 & TG3_FLG2_ANY_SERDES)
 			flowctrl = tg3_resolve_flowctrl_1000X(lcladv, rmtadv);
 		else
-			flowctrl = tg3_resolve_flowctrl_1000T(lcladv, rmtadv);
+			flowctrl = mii_resolve_flowctrl_fdx(lcladv, rmtadv);
 	} else
 		flowctrl = tp->link_config.flowctrl;
 

drivers/net/usb/smsc95xx.c

@@ -435,28 +435,6 @@ static void smsc95xx_set_multicast(struct net_device *netdev)
 	smsc95xx_write_reg_async(dev, MAC_CR, &pdata->mac_cr);
 }
 
-static u8 smsc95xx_resolve_flowctrl_fulldplx(u16 lcladv, u16 rmtadv)
-{
-	u8 cap = 0;
-
-	if (lcladv & ADVERTISE_PAUSE_CAP) {
-		if (lcladv & ADVERTISE_PAUSE_ASYM) {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
-			else if (rmtadv & LPA_PAUSE_ASYM)
-				cap = FLOW_CTRL_RX;
-		} else {
-			if (rmtadv & LPA_PAUSE_CAP)
-				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
-		}
-	} else if (lcladv & ADVERTISE_PAUSE_ASYM) {
-		if ((rmtadv & LPA_PAUSE_CAP) && (rmtadv & LPA_PAUSE_ASYM))
-			cap = FLOW_CTRL_TX;
-	}
-
-	return cap;
-}
-
 static void smsc95xx_phy_update_flowcontrol(struct usbnet *dev, u8 duplex,
 					    u16 lcladv, u16 rmtadv)
 {
@@ -469,7 +447,7 @@ static void smsc95xx_phy_update_flowcontrol(struct usbnet *dev, u8 duplex,
 	}
 
 	if (duplex == DUPLEX_FULL) {
-		u8 cap = smsc95xx_resolve_flowctrl_fulldplx(lcladv, rmtadv);
+		u8 cap = mii_resolve_flowctrl_fdx(lcladv, rmtadv);
 
 		if (cap & FLOW_CTRL_RX)
 			flow = 0xFFFF0002;

include/linux/mii.h

@@ -239,5 +239,34 @@ static inline unsigned int mii_duplex (unsigned int duplex_lock,
 	return 0;
 }
 
+/**
+ * mii_resolve_flowctrl_fdx
+ * @lcladv: value of MII ADVERTISE register
+ * @rmtadv: value of MII LPA register
+ *
+ * Resolve full duplex flow control as per IEEE 802.3-2005 table 28B-3
+ */
+static inline u8 mii_resolve_flowctrl_fdx(u16 lcladv, u16 rmtadv)
+{
+	u8 cap = 0;
+
+	if (lcladv & ADVERTISE_PAUSE_CAP) {
+		if (lcladv & ADVERTISE_PAUSE_ASYM) {
+			if (rmtadv & LPA_PAUSE_CAP)
+				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
+			else if (rmtadv & LPA_PAUSE_ASYM)
+				cap = FLOW_CTRL_RX;
+		} else {
+			if (rmtadv & LPA_PAUSE_CAP)
+				cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
+		}
+	} else if (lcladv & ADVERTISE_PAUSE_ASYM) {
+		if ((rmtadv & LPA_PAUSE_CAP) && (rmtadv & LPA_PAUSE_ASYM))
+			cap = FLOW_CTRL_TX;
+	}
+
+	return cap;
+}
+
 #endif /* __KERNEL__ */
 #endif /* __LINUX_MII_H__ */