ipg: run-time configurable jumbo frame support

Make jumbo frame support configurable via ifconfig mtu option as suggested by
Stephen Hemminger.

Cc: Stephen Hemminger <stephen.hemminger@vyatta.com>
Tested-by: Andrew Savchenko <Bircoph@list.ru>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/ipg.c

@@ -42,7 +42,6 @@
 #define ipg_r16(reg)		ioread16(ioaddr + (reg))
 #define ipg_r8(reg)		ioread8(ioaddr + (reg))
 
-#define JUMBO_FRAME_4k_ONLY
 enum {
 	netdev_io_size = 128
 };
@@ -54,6 +53,14 @@ MODULE_AUTHOR("IC Plus Corp. 2003");
 MODULE_DESCRIPTION("IC Plus IP1000 Gigabit Ethernet Adapter Linux Driver");
 MODULE_LICENSE("GPL");
 
+/*
+ * Defaults
+ */
+#define IPG_MAX_RXFRAME_SIZE	0x0600
+#define IPG_RXFRAG_SIZE		0x0600
+#define IPG_RXSUPPORT_SIZE	0x0600
+#define IPG_IS_JUMBO		false
+
 /*
  * Variable record -- index by leading revision/length
  * Revision/Length(=N*4), Address1, Data1, Address2, Data2,...,AddressN,DataN
@@ -1805,9 +1812,6 @@ static int ipg_nic_open(struct net_device *dev)
 	sp->jumbo.current_size = 0;
 	sp->jumbo.skb = NULL;
 
-	if (IPG_TXFRAG_SIZE)
-		dev->mtu = IPG_TXFRAG_SIZE;
-
 	/* Enable transmit and receive operation of the IPG. */
 	ipg_w32((ipg_r32(MAC_CTRL) | IPG_MC_RX_ENABLE | IPG_MC_TX_ENABLE) &
 		 IPG_MC_RSVD_MASK, MAC_CTRL);
@@ -2116,6 +2120,7 @@ static int ipg_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 static int ipg_nic_change_mtu(struct net_device *dev, int new_mtu)
 {
 	struct ipg_nic_private *sp = netdev_priv(dev);
+	int err;
 
 	/* Function to accomodate changes to Maximum Transfer Unit
 	 * (or MTU) of IPG NIC. Cannot use default function since
@@ -2124,16 +2129,33 @@ static int ipg_nic_change_mtu(struct net_device *dev, int new_mtu)
 
 	IPG_DEBUG_MSG("_nic_change_mtu\n");
 
-	/* Check that the new MTU value is between 68 (14 byte header, 46
-	 * byte payload, 4 byte FCS) and IPG_MAX_RXFRAME_SIZE, which
-	 * corresponds to the MAXFRAMESIZE register in the IPG.
+	/*
+	 * Check that the new MTU value is between 68 (14 byte header, 46 byte
+	 * payload, 4 byte FCS) and 10 KB, which is the largest supported MTU.
 	 */
-	if ((new_mtu < 68) || (new_mtu > sp->max_rxframe_size))
+	if (new_mtu < 68 || new_mtu > 10240)
 		return -EINVAL;
 
+	err = ipg_nic_stop(dev);
+	if (err)
+		return err;
+
 	dev->mtu = new_mtu;
 
-	return 0;
+	sp->max_rxframe_size = new_mtu;
+
+	sp->rxfrag_size = new_mtu;
+	if (sp->rxfrag_size > 4088)
+		sp->rxfrag_size = 4088;
+
+	sp->rxsupport_size = sp->max_rxframe_size;
+
+	if (new_mtu > 0x0600)
+		sp->is_jumbo = true;
+	else
+		sp->is_jumbo = false;
+
+	return ipg_nic_open(dev);
 }
 
 static int ipg_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
@@ -2238,7 +2260,7 @@ static int __devinit ipg_probe(struct pci_dev *pdev,
 	spin_lock_init(&sp->lock);
 	mutex_init(&sp->mii_mutex);
 
-	sp->is_jumbo = IPG_JUMBO;
+	sp->is_jumbo = IPG_IS_JUMBO;
 	sp->rxfrag_size = IPG_RXFRAG_SIZE;
 	sp->rxsupport_size = IPG_RXSUPPORT_SIZE;
 	sp->max_rxframe_size = IPG_MAX_RXFRAME_SIZE;

drivers/net/ipg.h

@@ -536,91 +536,6 @@ enum ipg_regs {
  */
 #define		IPG_FRAMESBETWEENTXDMACOMPLETES 0x1
 
-#ifdef JUMBO_FRAME
-# define IPG_JUMBO true
-#else
-# define IPG_JUMBO false
-#endif
-
-#ifdef JUMBO_FRAME
-
-# ifdef JUMBO_FRAME_SIZE_2K
-# define JUMBO_FRAME_SIZE 2048
-# define __IPG_RXFRAG_SIZE 2048
-# else
-#  ifdef JUMBO_FRAME_SIZE_3K
-#  define JUMBO_FRAME_SIZE 3072
-#  define __IPG_RXFRAG_SIZE 3072
-#  else
-#   ifdef JUMBO_FRAME_SIZE_4K
-#   define JUMBO_FRAME_SIZE 4096
-#   define __IPG_RXFRAG_SIZE 4088
-#   else
-#    ifdef JUMBO_FRAME_SIZE_5K
-#    define JUMBO_FRAME_SIZE 5120
-#    define __IPG_RXFRAG_SIZE 4088
-#    else
-#     ifdef JUMBO_FRAME_SIZE_6K
-#     define JUMBO_FRAME_SIZE 6144
-#     define __IPG_RXFRAG_SIZE 4088
-#     else
-#      ifdef JUMBO_FRAME_SIZE_7K
-#      define JUMBO_FRAME_SIZE 7168
-#      define __IPG_RXFRAG_SIZE 4088
-#      else
-#       ifdef JUMBO_FRAME_SIZE_8K
-#       define JUMBO_FRAME_SIZE 8192
-#       define __IPG_RXFRAG_SIZE 4088
-#       else
-#        ifdef JUMBO_FRAME_SIZE_9K
-#        define JUMBO_FRAME_SIZE 9216
-#        define __IPG_RXFRAG_SIZE 4088
-#        else
-#         ifdef JUMBO_FRAME_SIZE_10K
-#         define JUMBO_FRAME_SIZE 10240
-#         define __IPG_RXFRAG_SIZE 4088
-#         else
-#         define JUMBO_FRAME_SIZE 4096
-#         endif
-#        endif
-#       endif
-#      endif
-#     endif
-#    endif
-#   endif
-#  endif
-# endif
-#endif
-
-/* Size of allocated received buffers. Nominally 0x0600.
- * Define larger if expecting jumbo frames.
- */
-#ifdef JUMBO_FRAME
-/* IPG_TXFRAG_SIZE must <= 0x2b00, or TX will crash */
-#define		IPG_TXFRAG_SIZE		JUMBO_FRAME_SIZE
-#else
-#define		IPG_TXFRAG_SIZE		0 /* use default MTU */
-#endif
-
-/* Size of allocated received buffers. Nominally 0x0600.
- * Define larger if expecting jumbo frames.
- */
-#ifdef JUMBO_FRAME
-/* 4088 = 4096 - 8 */
-#define		IPG_RXFRAG_SIZE		__IPG_RXFRAG_SIZE
-#define     IPG_RXSUPPORT_SIZE   IPG_MAX_RXFRAME_SIZE
-#else
-#define		IPG_RXFRAG_SIZE		0x0600
-#define     IPG_RXSUPPORT_SIZE   IPG_RXFRAG_SIZE
-#endif
-
-/* IPG_MAX_RXFRAME_SIZE <= IPG_RXFRAG_SIZE */
-#ifdef JUMBO_FRAME
-#define		IPG_MAX_RXFRAME_SIZE		JUMBO_FRAME_SIZE
-#else
-#define		IPG_MAX_RXFRAME_SIZE		0x0600
-#endif
-
 #define		IPG_RFDLIST_LENGTH		0x100
 
 /* Maximum number of RFDs to process per interrupt.