bnx2: Set rx buffer water marks based on MTU.

The default rx buffer water marks for XOFF/XON are for 1500 MTU.  At
larger MTUs, these water marks need to be adjusted for effective
flow control.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index 617d953..2b9649ae 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -4199,7 +4199,14 @@
 
 #define BNX2_RBUF_CONFIG				0x0020000c
 #define BNX2_RBUF_CONFIG_XOFF_TRIP			 (0x3ffL<<0)
+#define BNX2_RBUF_CONFIG_XOFF_TRIP_VAL(mtu)		 \
+	((((mtu) - 1500) * 31 / 1000) + 54)
 #define BNX2_RBUF_CONFIG_XON_TRIP			 (0x3ffL<<16)
+#define BNX2_RBUF_CONFIG_XON_TRIP_VAL(mtu)		 \
+	((((mtu) - 1500) * 39 / 1000) + 66)
+#define BNX2_RBUF_CONFIG_VAL(mtu)			 \
+	(BNX2_RBUF_CONFIG_XOFF_TRIP_VAL(mtu) |		 \
+	(BNX2_RBUF_CONFIG_XON_TRIP_VAL(mtu) << 16))
 
 #define BNX2_RBUF_FW_BUF_ALLOC				0x00200010
 #define BNX2_RBUF_FW_BUF_ALLOC_VALUE			 (0x1ffL<<7)
@@ -4221,11 +4228,25 @@
 
 #define BNX2_RBUF_CONFIG2				0x0020001c
 #define BNX2_RBUF_CONFIG2_MAC_DROP_TRIP			 (0x3ffL<<0)
+#define BNX2_RBUF_CONFIG2_MAC_DROP_TRIP_VAL(mtu)	 \
+	((((mtu) - 1500) * 4 / 1000) + 5)
 #define BNX2_RBUF_CONFIG2_MAC_KEEP_TRIP			 (0x3ffL<<16)
+#define BNX2_RBUF_CONFIG2_MAC_KEEP_TRIP_VAL(mtu)	 \
+	((((mtu) - 1500) * 2 / 100) + 30)
+#define BNX2_RBUF_CONFIG2_VAL(mtu)			 \
+	(BNX2_RBUF_CONFIG2_MAC_DROP_TRIP_VAL(mtu) |	 \
+	(BNX2_RBUF_CONFIG2_MAC_KEEP_TRIP_VAL(mtu) << 16))
 
 #define BNX2_RBUF_CONFIG3				0x00200020
 #define BNX2_RBUF_CONFIG3_CU_DROP_TRIP			 (0x3ffL<<0)
+#define BNX2_RBUF_CONFIG3_CU_DROP_TRIP_VAL(mtu)		 \
+	((((mtu) - 1500) * 12 / 1000) + 18)
 #define BNX2_RBUF_CONFIG3_CU_KEEP_TRIP			 (0x3ffL<<16)
+#define BNX2_RBUF_CONFIG3_CU_KEEP_TRIP_VAL(mtu)		 \
+	((((mtu) - 1500) * 2 / 100) + 30)
+#define BNX2_RBUF_CONFIG3_VAL(mtu)			 \
+	(BNX2_RBUF_CONFIG3_CU_DROP_TRIP_VAL(mtu) |	 \
+	(BNX2_RBUF_CONFIG3_CU_KEEP_TRIP_VAL(mtu) << 16))
 
 #define BNX2_RBUF_PKT_DATA				0x00208000
 #define BNX2_RBUF_CLIST_DATA				0x00210000