net: Refactor full duplex flow control resolution

[karo-tx-linux.git] / include / linux / mii.h

diff --git a/include/linux/mii.h b/include/linux/mii.h
index 4a376e0816fde575774e66f5ffe7ce9a16bc045f..ad748588faf1a2c0e6af662dfd1e790ecc766aa9 100644 (file)
--- a/include/linux/mii.h
+++ b/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__ */