patch-2.3.42 linux/drivers/net/macmace.c

• Lines: 826
• Date: Mon Jan 31 10:34:12 2000
• Orig file: v2.3.41/linux/drivers/net/macmace.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.41/linux/drivers/net/macmace.c linux/drivers/net/macmace.c
@@ -0,0 +1,825 @@
+/*
+ *	Driver for the Macintosh 68K onboard MACE controller with PSC
+ *	driven DMA. The MACE driver code is derived from mace.c. The
+ *	Mac68k theory of operation is courtesy of the MacBSD wizards.
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	Copyright (C) 1996 Paul Mackerras.
+ *	Copyright (C) 1998 Alan Cox <alan@redhat.com>
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/irq.h>
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/mac_psc.h>
+#include "mace.h"
+
+#define N_RX_RING	8
+#define N_TX_RING	2
+#define MAX_TX_ACTIVE	1
+#define NCMDS_TX	1	/* dma commands per element in tx ring */
+#define RX_BUFLEN	(ETH_FRAME_LEN + 8)
+#define TX_TIMEOUT	HZ	/* 1 second */
+
+/* Bits in transmit DMA status */
+#define TX_DMA_ERR	0x80
+
+/* The MACE is simply wired down on a Mac68K box */
+
+#define MACE_BASE	(void *)(0x50F1C000)
+#define MACE_PROM	(void *)(0x50F08001)
+
+struct mace68k_data
+{
+	volatile struct mace *mace;
+	volatile unsigned char *tx_ring;
+	volatile unsigned char *rx_ring;
+	int dma_intr;
+	unsigned char maccc;
+	struct net_device_stats stats;
+	struct timer_list tx_timeout;
+	int timeout_active;
+	int rx_slot, rx_done;
+	int tx_slot, tx_count;
+};
+
+struct mace_frame
+{
+	u16	len;
+	u16	status;
+	u16	rntpc;
+	u16	rcvcc;
+	u32	pad1;
+	u32	pad2;
+	u8	data[1];	
+	/* And frame continues.. */
+};
+
+#define PRIV_BYTES	sizeof(struct mace68k_data)
+
+extern void psc_debug_dump(void);
+
+static int mace68k_open(struct net_device *dev);
+static int mace68k_close(struct net_device *dev);
+static int mace68k_xmit_start(struct sk_buff *skb, struct net_device *dev);
+static struct net_device_stats *mace68k_stats(struct net_device *dev);
+static void mace68k_set_multicast(struct net_device *dev);
+static void mace68k_reset(struct net_device *dev);
+static int mace68k_set_address(struct net_device *dev, void *addr);
+static void mace68k_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static void mace68k_dma_intr(int irq, void *dev_id, struct pt_regs *regs);
+static void mace68k_set_timeout(struct net_device *dev);
+static void mace68k_tx_timeout(unsigned long data);
+
+/*
+ *	PSC DMA engine control. As you'd expect on a macintosh its
+ *	more like a lawnmower engine supplied without instructions
+ *
+ *	The basic theory of operation appears to be as follows.
+ *
+ *	There are two sets of receive DMA registers and two sets
+ *	of transmit DMA registers. Instead of the more traditional
+ *	"ring buffer" approach the Mac68K DMA engine expects you
+ *	to be loading one chain while the other runs, and then
+ *	to flip register set. Each entry in the chain is a fixed 
+ *	length.
+ */
+
+/*
+ *	Load a receive DMA channel with a base address and ring length
+ */
+  
+static void psc_load_rxdma_base(int set, void *base)
+{
+	psc_write_word(PSC_ENETRD_CMD + set, 0x0100);
+	psc_write_long(PSC_ENETRD_ADDR + set, (u32)base);
+	psc_write_long(PSC_ENETRD_LEN + set, N_RX_RING);
+	psc_write_word(PSC_ENETRD_CMD + set, 0x9800);
+}
+
+/*
+ *	Reset the receive DMA subsystem
+ */
+  
+static void mace68k_rxdma_reset(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mace = mp->mace;
+	u8 mcc = mace->maccc;
+	
+	/*
+	 *	Turn off receive
+	 */
+	 
+	mcc&=~ENRCV;
+	mace->maccc=mcc;
+	
+	/*
+	 *	Program the DMA
+	 */
+	
+	psc_write_word(PSC_ENETRD_CTL, 0x8800);
+	psc_load_rxdma_base(0x0, (void *)virt_to_bus(mp->rx_ring));
+	psc_write_word(PSC_ENETRD_CTL, 0x0400);
+	
+	psc_write_word(PSC_ENETRD_CTL, 0x8800);
+	psc_load_rxdma_base(0x10, (void *)virt_to_bus(mp->rx_ring));
+	psc_write_word(PSC_ENETRD_CTL, 0x0400);
+	
+	mace->maccc=mcc|ENRCV;
+	
+#if 0
+	psc_write_word(PSC_ENETRD_CTL, 0x9800);
+	psc_write_word(PSC_ENETRD_CTL+0x10, 0x9800);
+#endif
+}
+
+/*
+ *	Reset the transmit DMA subsystem
+ */
+ 
+static void mace68k_txdma_reset(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mace = mp->mace;
+	u8 mcc = mace->maccc;
+
+	psc_write_word(PSC_ENETWR_CTL,0x8800);
+	
+	mace->maccc = mcc&~ENXMT;
+	psc_write_word(PSC_ENETWR_CTL,0x0400);
+	mace->maccc = mcc;
+}
+
+/*
+ *	Disable DMA
+ */
+ 
+static void mace68k_dma_off(struct net_device *dev)
+{
+	psc_write_word(PSC_ENETRD_CTL, 0x8800);
+	psc_write_word(PSC_ENETRD_CTL, 0x1000);
+	psc_write_word(PSC_ENETRD_CMD, 0x1100);
+	psc_write_word(PSC_ENETRD_CMD+0x10, 0x1100);
+                                        
+	psc_write_word(PSC_ENETWR_CTL, 0x8800);
+	psc_write_word(PSC_ENETWR_CTL, 0x1000);
+	psc_write_word(PSC_ENETWR_CMD, 0x1100);
+	psc_write_word(PSC_ENETWR_CMD+0x10, 0x1100);
+}
+
+/* Bit-reverse one byte of an ethernet hardware address. */
+
+static int bitrev(int b)
+{
+    int d = 0, i;
+
+    for (i = 0; i < 8; ++i, b >>= 1)
+	d = (d << 1) | (b & 1);
+    return d;
+}
+
+/*
+ * 	Not really much of a probe. The hardware table tells us if this
+ *	model of Macintrash has a MACE (AV macintoshes)
+ */
+ 
+int mace68k_probe(struct net_device *unused)
+{
+	int j;
+	static int once=0;
+	struct mace68k_data *mp;
+	unsigned char *addr;
+	struct net_device *dev;
+	unsigned char checksum = 0;
+	
+	/*
+	 *	There can be only one...
+	 */
+	 
+	if (once) return -ENODEV;
+	
+	once = 1;
+
+	if (macintosh_config->ether_type != MAC_ETHER_MACE) return -ENODEV;
+
+	printk("MACE ethernet should be present ");
+	
+	dev = init_etherdev(0, PRIV_BYTES);
+	if(dev==NULL)
+	{
+		printk("no free memory.\n");
+		return -ENOMEM;
+	}		
+	mp = (struct mace68k_data *) dev->priv;
+	dev->base_addr = (u32)MACE_BASE;
+	mp->mace = (volatile struct mace *) MACE_BASE;
+	
+	printk("at 0x%p", mp->mace);
+	
+	/*
+	 *	16K RX ring and 4K TX ring should do nicely
+	 */
+
+	mp->rx_ring=(void *)__get_free_pages(GFP_KERNEL, 2);
+	mp->tx_ring=(void *)__get_free_page(GFP_KERNEL);
+	
+	printk(".");
+	
+	if(mp->tx_ring==NULL || mp->rx_ring==NULL)
+	{
+		if(mp->tx_ring)
+			free_page((u32)mp->tx_ring);
+//		if(mp->rx_ring)
+//			__free_pages(mp->rx_ring,2);
+		printk("\nNo memory for ring buffers.\n");
+		return -ENOMEM;
+	}
+
+	/* We want the receive data to be uncached. We dont care about the
+	   byte reading order */
+
+	printk(".");	
+	kernel_set_cachemode((void *)mp->rx_ring, 16384, IOMAP_NOCACHE_NONSER);	
+	
+	printk(".");	
+	/* The transmit buffer needs to be write through */
+	kernel_set_cachemode((void *)mp->tx_ring, 4096, IOMAP_WRITETHROUGH);
+
+	printk(" Ok\n");	
+	dev->irq = IRQ_MAC_MACE;
+	printk(KERN_INFO "%s: MACE at", dev->name);
+
+	/*
+	 *	The PROM contains 8 bytes which total 0xFF when XOR'd
+	 *	together. Due to the usual peculiar apple brain damage
+	 *	the bytes are spaced out in a strange boundary and the
+	 * 	bits are reversed.
+	 */
+
+	addr = (void *)MACE_PROM;
+		 
+	for (j = 0; j < 6; ++j)
+	{
+		u8 v=bitrev(addr[j<<4]);
+		checksum^=v;
+		dev->dev_addr[j] = v;
+		printk("%c%.2x", (j ? ':' : ' '), dev->dev_addr[j]);
+	}
+	for (; j < 8; ++j)
+	{
+		checksum^=bitrev(addr[j<<4]);
+	}
+	
+	if(checksum!=0xFF)
+	{
+		printk(" (invalid checksum)\n");
+		return -ENODEV;
+	}		
+	printk("\n");
+
+	memset(&mp->stats, 0, sizeof(mp->stats));
+	init_timer(&mp->tx_timeout);
+	mp->timeout_active = 0;
+
+	dev->open = mace68k_open;
+	dev->stop = mace68k_close;
+	dev->hard_start_xmit = mace68k_xmit_start;
+	dev->get_stats = mace68k_stats;
+	dev->set_multicast_list = mace68k_set_multicast;
+	dev->set_mac_address = mace68k_set_address;
+
+	ether_setup(dev);
+
+	mp = (struct mace68k_data *) dev->priv;
+	mp->maccc = ENXMT | ENRCV;
+	mp->dma_intr = IRQ_MAC_MACE_DMA;
+
+	psc_write_word(PSC_ENETWR_CTL, 0x9000);
+	psc_write_word(PSC_ENETRD_CTL, 0x9000);
+	psc_write_word(PSC_ENETWR_CTL, 0x0400);
+	psc_write_word(PSC_ENETRD_CTL, 0x0400);
+                                        	
+	/* apple's driver doesn't seem to do this */
+	/* except at driver shutdown time...      */
+#if 0
+	mace68k_dma_off(dev);
+#endif
+
+	return 0;
+}
+
+/*
+ *	Reset a MACE controller
+ */
+ 
+static void mace68k_reset(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mb = mp->mace;
+	int i;
+
+	/* soft-reset the chip */
+	i = 200;
+	while (--i) {
+		mb->biucc = SWRST;
+		if (mb->biucc & SWRST) {
+			udelay(10);
+			continue;
+		}
+		break;
+	}
+	if (!i) {
+		printk(KERN_ERR "mace: cannot reset chip!\n");
+		return;
+	}
+
+	mb->biucc = XMTSP_64;
+	mb->imr = 0xff;		/* disable all intrs for now */
+	i = mb->ir;
+	mb->maccc = 0;		/* turn off tx, rx */
+	mb->utr = RTRD;
+	mb->fifocc = RCVFW_64;
+	mb->xmtfc = AUTO_PAD_XMIT;	/* auto-pad short frames */
+
+	/* load up the hardware address */
+	
+	mb->iac = ADDRCHG | PHYADDR;
+	
+	while ((mb->iac & ADDRCHG) != 0);
+	
+	for (i = 0; i < 6; ++i)
+		mb->padr = dev->dev_addr[i];
+
+	/* clear the multicast filter */
+	mb->iac = ADDRCHG | LOGADDR;
+
+	while ((mb->iac & ADDRCHG) != 0);
+	
+	for (i = 0; i < 8; ++i)
+		mb->ladrf = 0;
+
+	mb->plscc = PORTSEL_GPSI + ENPLSIO;
+}
+
+/*
+ *	Load the address on a mace controller.
+ */
+ 
+static int mace68k_set_address(struct net_device *dev, void *addr)
+{
+	unsigned char *p = addr;
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mb = mp->mace;
+	int i;
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+
+	/* load up the hardware address */
+	mb->iac = ADDRCHG | PHYADDR;
+	while ((mb->iac & ADDRCHG) != 0);
+	
+	for (i = 0; i < 6; ++i)
+		mb->padr = dev->dev_addr[i] = p[i];
+	/* note: setting ADDRCHG clears ENRCV */
+	mb->maccc = mp->maccc;
+	restore_flags(flags);
+	return 0;
+}
+
+/*
+ *	Open the Macintosh MACE. Most of this is playing with the DMA
+ *	engine. The ethernet chip is quite friendly.
+ */
+ 
+static int mace68k_open(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mb = mp->mace;
+
+	/* reset the chip */
+	mace68k_reset(dev);
+
+	mp->rx_done = 0;
+	mace68k_rxdma_reset(dev);
+
+	/*
+	 *	The interrupt is fixed and comes off the PSC.
+	 */
+	 
+	if (request_irq(dev->irq, mace68k_interrupt, 0, "68K MACE", dev))
+	{
+		printk(KERN_ERR "MACE: can't get irq %d\n", dev->irq);
+		return -EAGAIN;
+	}
+
+	/*
+	 *	Ditto the DMA interrupt.
+	 */
+	 
+	if (request_irq(IRQ_MAC_MACE_DMA, mace68k_dma_intr, 0, "68K MACE DMA",
+			dev))
+	{
+		printk(KERN_ERR "MACE: can't get irq %d\n", IRQ_MAC_MACE_DMA);
+		return -EAGAIN;
+	}
+
+	/* Activate the Mac DMA engine */
+
+	mp->tx_slot = 0;		/* Using register set 0 */
+	mp->tx_count = 1;		/* 1 Buffer ready for use */
+	mace68k_txdma_reset(dev);
+	
+	/* turn it on! */
+	mb->maccc = mp->maccc;
+	/* enable all interrupts except receive interrupts */
+	mb->imr = RCVINT;
+	return 0;
+}
+
+/*
+ *	Shut down the mace and its interrupt channel
+ */
+ 
+static int mace68k_close(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mb = mp->mace;
+
+	/* disable rx and tx */
+	mb->maccc = 0;
+	mb->imr = 0xff;		/* disable all intrs */
+
+	/* disable rx and tx dma */
+
+	mace68k_dma_off(dev);
+
+	free_irq(dev->irq, dev);
+	free_irq(IRQ_MAC_MACE_DMA, dev);
+	return 0;
+}
+
+static inline void mace68k_set_timeout(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+	if (mp->timeout_active)
+		del_timer(&mp->tx_timeout);
+	mp->tx_timeout.expires = jiffies + TX_TIMEOUT;
+	mp->tx_timeout.function = mace68k_tx_timeout;
+	mp->tx_timeout.data = (unsigned long) dev;
+	add_timer(&mp->tx_timeout);
+	mp->timeout_active = 1;
+	restore_flags(flags);
+}
+
+/*
+ *	Transmit a frame
+ */
+ 
+static int mace68k_xmit_start(struct sk_buff *skb, struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	/*
+	 *	This may need atomic types ???
+	 */
+
+	printk("mace68k_xmit_start: mp->tx_count = %d, dev->tbusy = %d, mp->tx_ring = %p (%p)\n",
+		mp->tx_count, dev->tbusy,
+		mp->tx_ring, virt_to_bus(mp->tx_ring));
+	psc_debug_dump();
+
+	if(mp->tx_count == 0)
+	{
+		dev->tbusy=1;
+		mace68k_dma_intr(IRQ_MAC_MACE_DMA, dev, NULL);
+		return 1;
+	}
+	mp->tx_count--;
+	
+	/*
+	 *	FIXME:
+	 *	This is hackish. The memcpy probably isnt needed but
+	 *	the rules for alignment are not known. Ideally we'd like
+	 *	to just blast the skb directly to ethernet. We also don't
+	 *	use the ring properly - just a one frame buffer. That
+	 *	also requires cache pushes ;).
+	 */
+	memcpy((void *)mp->tx_ring, skb, skb->len);
+	psc_write_long(PSC_ENETWR_ADDR + mp->tx_slot, virt_to_bus(mp->tx_ring));
+        psc_write_long(PSC_ENETWR_LEN + mp->tx_slot, skb->len);
+        psc_write_word(PSC_ENETWR_CMD + mp->tx_slot, 0x9800);                       
+	mp->stats.tx_packets++;
+	mp->stats.tx_bytes+=skb->len;
+        dev_kfree_skb(skb);
+	return 0;
+}
+
+static struct net_device_stats *mace68k_stats(struct net_device *dev)
+{
+	struct mace68k_data *p = (struct mace68k_data *) dev->priv;
+	return &p->stats;
+}
+
+/*
+ * CRC polynomial - used in working out multicast filter bits.
+ */
+#define CRC_POLY	0xedb88320
+
+static void mace68k_set_multicast(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mb = mp->mace;
+	int i, j, k, b;
+	unsigned long crc;
+
+	mp->maccc &= ~PROM;
+	if (dev->flags & IFF_PROMISC)
+	{
+		mp->maccc |= PROM;
+	} else
+	{
+		unsigned char multicast_filter[8];
+		struct dev_mc_list *dmi = dev->mc_list;
+
+		if (dev->flags & IFF_ALLMULTI)
+		{
+			for (i = 0; i < 8; i++)
+				multicast_filter[i] = 0xff;
+		} else
+		{
+			for (i = 0; i < 8; i++)
+				multicast_filter[i] = 0;
+			for (i = 0; i < dev->mc_count; i++)
+			{
+				crc = ~0;
+				for (j = 0; j < 6; ++j)
+				{
+					b = dmi->dmi_addr[j];
+					for (k = 0; k < 8; ++k)
+					{
+						if ((crc ^ b) & 1)
+							crc = (crc >> 1) ^ CRC_POLY;
+						else
+							crc >>= 1;
+						b >>= 1;
+					}
+				}
+				j = crc >> 26;	/* bit number in multicast_filter */
+				multicast_filter[j >> 3] |= 1 << (j & 7);
+				dmi = dmi->next;
+			}
+		}
+#if 0
+		printk("Multicast filter :");
+		for (i = 0; i < 8; i++)
+			printk("%02x ", multicast_filter[i]);
+		printk("\n");
+#endif
+
+		mb->iac = ADDRCHG | LOGADDR;
+		while ((mb->iac & ADDRCHG) != 0);
+		
+		for (i = 0; i < 8; ++i)
+			mb->ladrf = multicast_filter[i];
+	}
+	/* reset maccc */
+	mb->maccc = mp->maccc;
+}
+
+/*
+ *	Miscellaneous interrupts are handled here. We may end up 
+ *	having to bash the chip on the head for bad errors
+ */
+ 
+static void mace68k_handle_misc_intrs(struct mace68k_data *mp, int intr)
+{
+	volatile struct mace *mb = mp->mace;
+	static int mace68k_babbles, mace68k_jabbers;
+
+	if (intr & MPCO)
+		mp->stats.rx_missed_errors += 256;
+	mp->stats.rx_missed_errors += mb->mpc;	/* reading clears it */
+	if (intr & RNTPCO)
+		mp->stats.rx_length_errors += 256;
+	mp->stats.rx_length_errors += mb->rntpc;	/* reading clears it */
+	if (intr & CERR)
+		++mp->stats.tx_heartbeat_errors;
+	if (intr & BABBLE)
+		if (mace68k_babbles++ < 4)
+			printk(KERN_DEBUG "mace: babbling transmitter\n");
+	if (intr & JABBER)
+		if (mace68k_jabbers++ < 4)
+			printk(KERN_DEBUG "mace: jabbering transceiver\n");
+}
+
+/*
+ *	A transmit error has occured. (We kick the transmit side from
+ *	the DMA completion)
+ */
+ 
+static void mace68k_xmit_error(struct net_device *dev)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mb = mp->mace;
+	u8 xmtfs, xmtrc;
+	
+	xmtfs = mb->xmtfs;
+	xmtrc = mb->xmtrc;
+	
+	if(xmtfs & XMTSV)
+	{
+		if(xmtfs & UFLO)
+		{
+			printk("%s: DMA underrun.\n", dev->name);
+			mp->stats.tx_errors++;
+			mp->stats.tx_fifo_errors++;
+			mace68k_reset(dev);
+		}
+		if(xmtfs & RTRY)
+			mp->stats.collisions++;
+	}			
+	mark_bh(NET_BH);
+}
+
+/*
+ *	A receive interrupt occured.
+ */
+ 
+static void mace68k_recv_interrupt(struct net_device *dev)
+{
+//	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+//	volatile struct mace *mb = mp->mace;
+}
+
+/*
+ *	Process the chip interrupt
+ */
+ 
+static void mace68k_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct net_device *dev = (struct net_device *) dev_id;
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	volatile struct mace *mb = mp->mace;
+	u8 ir;
+	
+	ir = mb->ir;
+	mace68k_handle_misc_intrs(mp, ir);
+	
+	if(ir&XMTINT)
+		mace68k_xmit_error(dev);
+	if(ir&RCVINT)
+		mace68k_recv_interrupt(dev);
+}
+
+static void mace68k_tx_timeout(unsigned long data)
+{
+//	struct net_device *dev = (struct net_device *) data;
+//	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+//	volatile struct mace *mb = mp->mace;
+}
+
+/*
+ *	Handle a newly arrived frame
+ */
+ 
+static void mace_dma_rx_frame(struct net_device *dev, struct mace_frame *mf)
+{
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+	struct sk_buff *skb;
+
+	if(mf->status&RS_OFLO)
+	{
+		printk("%s: fifo overflow.\n", dev->name);
+		mp->stats.rx_errors++;
+		mp->stats.rx_fifo_errors++;
+	}
+	if(mf->status&(RS_CLSN|RS_FRAMERR|RS_FCSERR))
+		mp->stats.rx_errors++;
+		
+	if(mf->status&RS_CLSN)
+		mp->stats.collisions++;
+	if(mf->status&RS_FRAMERR)
+		mp->stats.rx_frame_errors++;
+	if(mf->status&RS_FCSERR)
+		mp->stats.rx_crc_errors++;
+		
+	skb = dev_alloc_skb(mf->len+2);
+	if(skb==NULL)
+	{
+		mp->stats.rx_dropped++;
+		return;
+	}
+	skb_reserve(skb,2);
+	memcpy(skb_put(skb, mf->len), mf->data, mf->len);
+	
+	skb->protocol = eth_type_trans(skb, dev);
+	netif_rx(skb);
+	mp->stats.rx_packets++;
+	mp->stats.rx_bytes+=mf->len;
+}
+
+/*
+ *	The PSC has passed us a DMA interrupt event.
+ */
+ 
+static void mace68k_dma_intr(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct net_device *dev = (struct net_device *) dev_id;
+	struct mace68k_data *mp = (struct mace68k_data *) dev->priv;
+
+#if 0
+	u32 psc_status;
+	
+	/* It seems this must be allowed to stabilise ?? */
+	
+	while((psc_status=psc_read_long(0x0804))!=psc_read_long(0x0804));
+
+	/*
+	 *	Was this an ethernet event ?
+	 */
+	 	
+	if(psc_status&0x60000000)
+	{
+#endif
+		/*
+		 *	Process the read queue
+		 */
+		 
+		u16 psc_status = psc_read_word(PSC_ENETRD_CTL);
+		
+		printk("mace68k_dma_intr: PSC_ENETRD_CTL = %04X\n", (uint) psc_status);
+
+		if (psc_status & 0x2000) {
+			mace68k_rxdma_reset(dev);
+			mp->rx_done = 0;
+		} else if (psc_status & 0x100) {
+			int left;
+			
+			psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x1100);
+			left=psc_read_long(PSC_ENETRD_LEN + mp->rx_slot);
+			/* read packets */	
+			
+			while(mp->rx_done < left)
+			{
+				struct mace_frame *mf=((struct mace_frame *)
+					mp->rx_ring)+mp->rx_done++;
+				mace_dma_rx_frame(dev, mf);
+			}
+			
+			if(left == 0)	/* Out of DMA room */
+			{
+				psc_load_rxdma_base(mp->rx_slot, 
+					(void *)virt_to_phys(mp->rx_ring));
+				mp->rx_slot^=16;
+				mp->rx_done = 0;
+			}
+			else
+			{
+				psc_write_word(PSC_ENETRD_CMD+mp->rx_slot,
+					0x9800);
+			}
+					
+		}
+		
+		/*
+		 *	Process the write queue
+		 */
+		 
+		psc_status = psc_read_word(PSC_ENETWR_CTL);
+		printk("mace68k_dma_intr: PSC_ENETWR_CTL = %04X\n", (uint) psc_status);
+
+		/* apple's driver seems to loop over this until neither */
+		/* condition is true.    - jmt                          */
+
+		if (psc_status & 0x2000) {
+			mace68k_txdma_reset(dev);
+		} else if (psc_status & 0x0100) {
+			psc_write_word(PSC_ENETWR_CMD + mp->tx_slot, 0x0100);
+			mp->tx_slot ^=16;
+			mp->tx_count++;
+			dev->tbusy = 0;
+			mark_bh(NET_BH);
+		}
+#if 0
+	}
+#endif
+}