Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 770 insertions, 0 deletions

diff --git a/drivers/net/ethernet/apple/macmace.c b/drivers/net/ethernet/apple/macmace.c
new file mode 100644
index 0000000000..8775c3234e
--- /dev/null
+++ b/drivers/net/ethernet/apple/macmace.c
@@ -0,0 +1,770 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	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.
+ *
+ *	Copyright (C) 1996 Paul Mackerras.
+ *	Copyright (C) 1998 Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ *	Modified heavily by Joshua M. Thompson based on Dave Huang's NetBSD driver
+ *
+ *	Copyright (C) 2007 Finn Thain
+ *
+ *	Converted to DMA API, converted to unified driver model,
+ *	sync'd some routines with mace.c and fixed various bugs.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/crc32.h>
+#include <linux/bitrev.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/gfp.h>
+#include <linux/interrupt.h>
+#include <asm/io.h>
+#include <asm/macints.h>
+#include <asm/mac_psc.h>
+#include <asm/page.h>
+#include "mace.h"
+
+static char mac_mace_string[] = "macmace";
+
+#define N_TX_BUFF_ORDER	0
+#define N_TX_RING	(1 << N_TX_BUFF_ORDER)
+#define N_RX_BUFF_ORDER	3
+#define N_RX_RING	(1 << N_RX_BUFF_ORDER)
+
+#define TX_TIMEOUT	HZ
+
+#define MACE_BUFF_SIZE	0x800
+
+/* Chip rev needs workaround on HW & multicast addr change */
+#define BROKEN_ADDRCHG_REV	0x0941
+
+/* The MACE is simply wired down on a Mac68K box */
+
+#define MACE_BASE	(void *)(0x50F1C000)
+#define MACE_PROM	(void *)(0x50F08001)
+
+struct mace_data {
+	volatile struct mace *mace;
+	unsigned char *tx_ring;
+	dma_addr_t tx_ring_phys;
+	unsigned char *rx_ring;
+	dma_addr_t rx_ring_phys;
+	int dma_intr;
+	int rx_slot, rx_tail;
+	int tx_slot, tx_sloti, tx_count;
+	int chipid;
+	struct device *device;
+};
+
+struct mace_frame {
+	u8	rcvcnt;
+	u8	pad1;
+	u8	rcvsts;
+	u8	pad2;
+	u8	rntpc;
+	u8	pad3;
+	u8	rcvcc;
+	u8	pad4;
+	u32	pad5;
+	u32	pad6;
+	DECLARE_FLEX_ARRAY(u8, data);
+	/* And frame continues.. */
+};
+
+#define PRIV_BYTES	sizeof(struct mace_data)
+
+static int mace_open(struct net_device *dev);
+static int mace_close(struct net_device *dev);
+static netdev_tx_t mace_xmit_start(struct sk_buff *skb, struct net_device *dev);
+static void mace_set_multicast(struct net_device *dev);
+static int mace_set_address(struct net_device *dev, void *addr);
+static void mace_reset(struct net_device *dev);
+static irqreturn_t mace_interrupt(int irq, void *dev_id);
+static irqreturn_t mace_dma_intr(int irq, void *dev_id);
+static void mace_tx_timeout(struct net_device *dev, unsigned int txqueue);
+static void __mace_set_address(struct net_device *dev, const void *addr);
+
+/*
+ * Load a receive DMA channel with a base address and ring length
+ */
+
+static void mace_load_rxdma_base(struct net_device *dev, int set)
+{
+	struct mace_data *mp = netdev_priv(dev);
+
+	psc_write_word(PSC_ENETRD_CMD + set, 0x0100);
+	psc_write_long(PSC_ENETRD_ADDR + set, (u32) mp->rx_ring_phys);
+	psc_write_long(PSC_ENETRD_LEN + set, N_RX_RING);
+	psc_write_word(PSC_ENETRD_CMD + set, 0x9800);
+	mp->rx_tail = 0;
+}
+
+/*
+ * Reset the receive DMA subsystem
+ */
+
+static void mace_rxdma_reset(struct net_device *dev)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mace = mp->mace;
+	u8 maccc = mace->maccc;
+
+	mace->maccc = maccc & ~ENRCV;
+
+	psc_write_word(PSC_ENETRD_CTL, 0x8800);
+	mace_load_rxdma_base(dev, 0x00);
+	psc_write_word(PSC_ENETRD_CTL, 0x0400);
+
+	psc_write_word(PSC_ENETRD_CTL, 0x8800);
+	mace_load_rxdma_base(dev, 0x10);
+	psc_write_word(PSC_ENETRD_CTL, 0x0400);
+
+	mace->maccc = maccc;
+	mp->rx_slot = 0;
+
+	psc_write_word(PSC_ENETRD_CMD + PSC_SET0, 0x9800);
+	psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x9800);
+}
+
+/*
+ * Reset the transmit DMA subsystem
+ */
+
+static void mace_txdma_reset(struct net_device *dev)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mace = mp->mace;
+	u8 maccc;
+
+	psc_write_word(PSC_ENETWR_CTL, 0x8800);
+
+	maccc = mace->maccc;
+	mace->maccc = maccc & ~ENXMT;
+
+	mp->tx_slot = mp->tx_sloti = 0;
+	mp->tx_count = N_TX_RING;
+
+	psc_write_word(PSC_ENETWR_CTL, 0x0400);
+	mace->maccc = maccc;
+}
+
+/*
+ * Disable DMA
+ */
+
+static void mace_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 + PSC_SET0, 0x1100);
+	psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x1100);
+
+	psc_write_word(PSC_ENETWR_CTL, 0x8800);
+	psc_write_word(PSC_ENETWR_CTL, 0x1000);
+	psc_write_word(PSC_ENETWR_CMD + PSC_SET0, 0x1100);
+	psc_write_word(PSC_ENETWR_CMD + PSC_SET1, 0x1100);
+}
+
+static const struct net_device_ops mace_netdev_ops = {
+	.ndo_open		= mace_open,
+	.ndo_stop		= mace_close,
+	.ndo_start_xmit		= mace_xmit_start,
+	.ndo_tx_timeout		= mace_tx_timeout,
+	.ndo_set_rx_mode	= mace_set_multicast,
+	.ndo_set_mac_address	= mace_set_address,
+	.ndo_validate_addr	= eth_validate_addr,
+};
+
+/*
+ * Not really much of a probe. The hardware table tells us if this
+ * model of Macintrash has a MACE (AV macintoshes)
+ */
+
+static int mace_probe(struct platform_device *pdev)
+{
+	int j;
+	struct mace_data *mp;
+	unsigned char *addr;
+	struct net_device *dev;
+	unsigned char checksum = 0;
+	u8 macaddr[ETH_ALEN];
+	int err;
+
+	dev = alloc_etherdev(PRIV_BYTES);
+	if (!dev)
+		return -ENOMEM;
+
+	mp = netdev_priv(dev);
+
+	mp->device = &pdev->dev;
+	platform_set_drvdata(pdev, dev);
+	SET_NETDEV_DEV(dev, &pdev->dev);
+
+	dev->base_addr = (u32)MACE_BASE;
+	mp->mace = MACE_BASE;
+
+	dev->irq = IRQ_MAC_MACE;
+	mp->dma_intr = IRQ_MAC_MACE_DMA;
+
+	mp->chipid = mp->mace->chipid_hi << 8 | mp->mace->chipid_lo;
+
+	/*
+	 * 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 = MACE_PROM;
+
+	for (j = 0; j < 6; ++j) {
+		u8 v = bitrev8(addr[j<<4]);
+		checksum ^= v;
+		macaddr[j] = v;
+	}
+	eth_hw_addr_set(dev, macaddr);
+	for (; j < 8; ++j) {
+		checksum ^= bitrev8(addr[j<<4]);
+	}
+
+	if (checksum != 0xFF) {
+		free_netdev(dev);
+		return -ENODEV;
+	}
+
+	dev->netdev_ops		= &mace_netdev_ops;
+	dev->watchdog_timeo	= TX_TIMEOUT;
+
+	pr_info("Onboard MACE, hardware address %pM, chip revision 0x%04X\n",
+		dev->dev_addr, mp->chipid);
+
+	err = register_netdev(dev);
+	if (!err)
+		return 0;
+
+	free_netdev(dev);
+	return err;
+}
+
+/*
+ * Reset the chip.
+ */
+
+static void mace_reset(struct net_device *dev)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	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 "macmace: cannot reset chip!\n");
+		return;
+	}
+
+	mb->maccc = 0;	/* turn off tx, rx */
+	mb->imr = 0xFF;	/* disable all intrs for now */
+	i = mb->ir;
+
+	mb->biucc = XMTSP_64;
+	mb->utr = RTRD;
+	mb->fifocc = XMTFW_8 | RCVFW_64 | XMTFWU | RCVFWU;
+
+	mb->xmtfc = AUTO_PAD_XMIT; /* auto-pad short frames */
+	mb->rcvfc = 0;
+
+	/* load up the hardware address */
+	__mace_set_address(dev, dev->dev_addr);
+
+	/* clear the multicast filter */
+	if (mp->chipid == BROKEN_ADDRCHG_REV)
+		mb->iac = LOGADDR;
+	else {
+		mb->iac = ADDRCHG | LOGADDR;
+		while ((mb->iac & ADDRCHG) != 0)
+			;
+	}
+	for (i = 0; i < 8; ++i)
+		mb->ladrf = 0;
+
+	/* done changing address */
+	if (mp->chipid != BROKEN_ADDRCHG_REV)
+		mb->iac = 0;
+
+	mb->plscc = PORTSEL_AUI;
+}
+
+/*
+ * Load the address on a mace controller.
+ */
+
+static void __mace_set_address(struct net_device *dev, const void *addr)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+	const unsigned char *p = addr;
+	u8 macaddr[ETH_ALEN];
+	int i;
+
+	/* load up the hardware address */
+	if (mp->chipid == BROKEN_ADDRCHG_REV)
+		mb->iac = PHYADDR;
+	else {
+		mb->iac = ADDRCHG | PHYADDR;
+		while ((mb->iac & ADDRCHG) != 0)
+			;
+	}
+	for (i = 0; i < 6; ++i)
+		mb->padr = macaddr[i] = p[i];
+	eth_hw_addr_set(dev, macaddr);
+	if (mp->chipid != BROKEN_ADDRCHG_REV)
+		mb->iac = 0;
+}
+
+static int mace_set_address(struct net_device *dev, void *addr)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+	unsigned long flags;
+	u8 maccc;
+
+	local_irq_save(flags);
+
+	maccc = mb->maccc;
+
+	__mace_set_address(dev, addr);
+
+	mb->maccc = maccc;
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+/*
+ * Open the Macintosh MACE. Most of this is playing with the DMA
+ * engine. The ethernet chip is quite friendly.
+ */
+
+static int mace_open(struct net_device *dev)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+
+	/* reset the chip */
+	mace_reset(dev);
+
+	if (request_irq(dev->irq, mace_interrupt, 0, dev->name, dev)) {
+		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, dev->irq);
+		return -EAGAIN;
+	}
+	if (request_irq(mp->dma_intr, mace_dma_intr, 0, dev->name, dev)) {
+		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, mp->dma_intr);
+		free_irq(dev->irq, dev);
+		return -EAGAIN;
+	}
+
+	/* Allocate the DMA ring buffers */
+
+	mp->tx_ring = dma_alloc_coherent(mp->device,
+					 N_TX_RING * MACE_BUFF_SIZE,
+					 &mp->tx_ring_phys, GFP_KERNEL);
+	if (mp->tx_ring == NULL)
+		goto out1;
+
+	mp->rx_ring = dma_alloc_coherent(mp->device,
+					 N_RX_RING * MACE_BUFF_SIZE,
+					 &mp->rx_ring_phys, GFP_KERNEL);
+	if (mp->rx_ring == NULL)
+		goto out2;
+
+	mace_dma_off(dev);
+
+	/* Not sure what these do */
+
+	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);
+
+	mace_rxdma_reset(dev);
+	mace_txdma_reset(dev);
+
+	/* turn it on! */
+	mb->maccc = ENXMT | ENRCV;
+	/* enable all interrupts except receive interrupts */
+	mb->imr = RCVINT;
+	return 0;
+
+out2:
+	dma_free_coherent(mp->device, N_TX_RING * MACE_BUFF_SIZE,
+	                  mp->tx_ring, mp->tx_ring_phys);
+out1:
+	free_irq(dev->irq, dev);
+	free_irq(mp->dma_intr, dev);
+	return -ENOMEM;
+}
+
+/*
+ * Shut down the mace and its interrupt channel
+ */
+
+static int mace_close(struct net_device *dev)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+
+	mb->maccc = 0;		/* disable rx and tx	 */
+	mb->imr = 0xFF;		/* disable all irqs	 */
+	mace_dma_off(dev);	/* disable rx and tx dma */
+
+	return 0;
+}
+
+/*
+ * Transmit a frame
+ */
+
+static netdev_tx_t mace_xmit_start(struct sk_buff *skb, struct net_device *dev)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	unsigned long flags;
+
+	/* Stop the queue since there's only the one buffer */
+
+	local_irq_save(flags);
+	netif_stop_queue(dev);
+	if (!mp->tx_count) {
+		printk(KERN_ERR "macmace: tx queue running but no free buffers.\n");
+		local_irq_restore(flags);
+		return NETDEV_TX_BUSY;
+	}
+	mp->tx_count--;
+	local_irq_restore(flags);
+
+	dev->stats.tx_packets++;
+	dev->stats.tx_bytes += skb->len;
+
+	/* We need to copy into our xmit buffer to take care of alignment and caching issues */
+	skb_copy_from_linear_data(skb, mp->tx_ring, skb->len);
+
+	/* load the Tx DMA and fire it off */
+
+	psc_write_long(PSC_ENETWR_ADDR + mp->tx_slot, (u32)  mp->tx_ring_phys);
+	psc_write_long(PSC_ENETWR_LEN + mp->tx_slot, skb->len);
+	psc_write_word(PSC_ENETWR_CMD + mp->tx_slot, 0x9800);
+
+	mp->tx_slot ^= 0x10;
+
+	dev_kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
+static void mace_set_multicast(struct net_device *dev)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+	int i;
+	u32 crc;
+	u8 maccc;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	maccc = mb->maccc;
+	mb->maccc &= ~PROM;
+
+	if (dev->flags & IFF_PROMISC) {
+		mb->maccc |= PROM;
+	} else {
+		unsigned char multicast_filter[8];
+		struct netdev_hw_addr *ha;
+
+		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;
+			netdev_for_each_mc_addr(ha, dev) {
+				crc = ether_crc_le(6, ha->addr);
+				/* bit number in multicast_filter */
+				i = crc >> 26;
+				multicast_filter[i >> 3] |= 1 << (i & 7);
+			}
+		}
+
+		if (mp->chipid == BROKEN_ADDRCHG_REV)
+			mb->iac = LOGADDR;
+		else {
+			mb->iac = ADDRCHG | LOGADDR;
+			while ((mb->iac & ADDRCHG) != 0)
+				;
+		}
+		for (i = 0; i < 8; ++i)
+			mb->ladrf = multicast_filter[i];
+		if (mp->chipid != BROKEN_ADDRCHG_REV)
+			mb->iac = 0;
+	}
+
+	mb->maccc = maccc;
+	local_irq_restore(flags);
+}
+
+static void mace_handle_misc_intrs(struct net_device *dev, int intr)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+	static int mace_babbles, mace_jabbers;
+
+	if (intr & MPCO)
+		dev->stats.rx_missed_errors += 256;
+	dev->stats.rx_missed_errors += mb->mpc;   /* reading clears it */
+	if (intr & RNTPCO)
+		dev->stats.rx_length_errors += 256;
+	dev->stats.rx_length_errors += mb->rntpc; /* reading clears it */
+	if (intr & CERR)
+		++dev->stats.tx_heartbeat_errors;
+	if (intr & BABBLE)
+		if (mace_babbles++ < 4)
+			printk(KERN_DEBUG "macmace: babbling transmitter\n");
+	if (intr & JABBER)
+		if (mace_jabbers++ < 4)
+			printk(KERN_DEBUG "macmace: jabbering transceiver\n");
+}
+
+static irqreturn_t mace_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = (struct net_device *) dev_id;
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+	int intr, fs;
+	unsigned long flags;
+
+	/* don't want the dma interrupt handler to fire */
+	local_irq_save(flags);
+
+	intr = mb->ir; /* read interrupt register */
+	mace_handle_misc_intrs(dev, intr);
+
+	if (intr & XMTINT) {
+		fs = mb->xmtfs;
+		if ((fs & XMTSV) == 0) {
+			printk(KERN_ERR "macmace: xmtfs not valid! (fs=%x)\n", fs);
+			mace_reset(dev);
+			/*
+			 * XXX mace likes to hang the machine after a xmtfs error.
+			 * This is hard to reproduce, resetting *may* help
+			 */
+		}
+		/* dma should have finished */
+		if (!mp->tx_count) {
+			printk(KERN_DEBUG "macmace: tx ring ran out? (fs=%x)\n", fs);
+		}
+		/* Update stats */
+		if (fs & (UFLO|LCOL|LCAR|RTRY)) {
+			++dev->stats.tx_errors;
+			if (fs & LCAR)
+				++dev->stats.tx_carrier_errors;
+			else if (fs & (UFLO|LCOL|RTRY)) {
+				++dev->stats.tx_aborted_errors;
+				if (mb->xmtfs & UFLO) {
+					dev->stats.tx_fifo_errors++;
+					mace_txdma_reset(dev);
+				}
+			}
+		}
+	}
+
+	if (mp->tx_count)
+		netif_wake_queue(dev);
+
+	local_irq_restore(flags);
+
+	return IRQ_HANDLED;
+}
+
+static void mace_tx_timeout(struct net_device *dev, unsigned int txqueue)
+{
+	struct mace_data *mp = netdev_priv(dev);
+	volatile struct mace *mb = mp->mace;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	/* turn off both tx and rx and reset the chip */
+	mb->maccc = 0;
+	printk(KERN_ERR "macmace: transmit timeout - resetting\n");
+	mace_txdma_reset(dev);
+	mace_reset(dev);
+
+	/* restart rx dma */
+	mace_rxdma_reset(dev);
+
+	mp->tx_count = N_TX_RING;
+	netif_wake_queue(dev);
+
+	/* turn it on! */
+	mb->maccc = ENXMT | ENRCV;
+	/* enable all interrupts except receive interrupts */
+	mb->imr = RCVINT;
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Handle a newly arrived frame
+ */
+
+static void mace_dma_rx_frame(struct net_device *dev, struct mace_frame *mf)
+{
+	struct sk_buff *skb;
+	unsigned int frame_status = mf->rcvsts;
+
+	if (frame_status & (RS_OFLO | RS_CLSN | RS_FRAMERR | RS_FCSERR)) {
+		dev->stats.rx_errors++;
+		if (frame_status & RS_OFLO)
+			dev->stats.rx_fifo_errors++;
+		if (frame_status & RS_CLSN)
+			dev->stats.collisions++;
+		if (frame_status & RS_FRAMERR)
+			dev->stats.rx_frame_errors++;
+		if (frame_status & RS_FCSERR)
+			dev->stats.rx_crc_errors++;
+	} else {
+		unsigned int frame_length = mf->rcvcnt + ((frame_status & 0x0F) << 8 );
+
+		skb = netdev_alloc_skb(dev, frame_length + 2);
+		if (!skb) {
+			dev->stats.rx_dropped++;
+			return;
+		}
+		skb_reserve(skb, 2);
+		skb_put_data(skb, mf->data, frame_length);
+
+		skb->protocol = eth_type_trans(skb, dev);
+		netif_rx(skb);
+		dev->stats.rx_packets++;
+		dev->stats.rx_bytes += frame_length;
+	}
+}
+
+/*
+ * The PSC has passed us a DMA interrupt event.
+ */
+
+static irqreturn_t mace_dma_intr(int irq, void *dev_id)
+{
+	struct net_device *dev = (struct net_device *) dev_id;
+	struct mace_data *mp = netdev_priv(dev);
+	int left, head;
+	u16 status;
+	u32 baka;
+
+	/* Not sure what this does */
+
+	while ((baka = psc_read_long(PSC_MYSTERY)) != psc_read_long(PSC_MYSTERY));
+	if (!(baka & 0x60000000)) return IRQ_NONE;
+
+	/*
+	 * Process the read queue
+	 */
+
+	status = psc_read_word(PSC_ENETRD_CTL);
+
+	if (status & 0x2000) {
+		mace_rxdma_reset(dev);
+	} else if (status & 0x0100) {
+		psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x1100);
+
+		left = psc_read_long(PSC_ENETRD_LEN + mp->rx_slot);
+		head = N_RX_RING - left;
+
+		/* Loop through the ring buffer and process new packages */
+
+		while (mp->rx_tail < head) {
+			mace_dma_rx_frame(dev, (struct mace_frame*) (mp->rx_ring
+				+ (mp->rx_tail * MACE_BUFF_SIZE)));
+			mp->rx_tail++;
+		}
+
+		/* If we're out of buffers in this ring then switch to */
+		/* the other set, otherwise just reactivate this one.  */
+
+		if (!left) {
+			mace_load_rxdma_base(dev, mp->rx_slot);
+			mp->rx_slot ^= 0x10;
+		} else {
+			psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x9800);
+		}
+	}
+
+	/*
+	 * Process the write queue
+	 */
+
+	status = psc_read_word(PSC_ENETWR_CTL);
+
+	if (status & 0x2000) {
+		mace_txdma_reset(dev);
+	} else if (status & 0x0100) {
+		psc_write_word(PSC_ENETWR_CMD + mp->tx_sloti, 0x0100);
+		mp->tx_sloti ^= 0x10;
+		mp->tx_count++;
+	}
+	return IRQ_HANDLED;
+}
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Macintosh MACE ethernet driver");
+MODULE_ALIAS("platform:macmace");
+
+static int mac_mace_device_remove(struct platform_device *pdev)
+{
+	struct net_device *dev = platform_get_drvdata(pdev);
+	struct mace_data *mp = netdev_priv(dev);
+
+	unregister_netdev(dev);
+
+	free_irq(dev->irq, dev);
+	free_irq(IRQ_MAC_MACE_DMA, dev);
+
+	dma_free_coherent(mp->device, N_RX_RING * MACE_BUFF_SIZE,
+	                  mp->rx_ring, mp->rx_ring_phys);
+	dma_free_coherent(mp->device, N_TX_RING * MACE_BUFF_SIZE,
+	                  mp->tx_ring, mp->tx_ring_phys);
+
+	free_netdev(dev);
+
+	return 0;
+}
+
+static struct platform_driver mac_mace_driver = {
+	.probe  = mace_probe,
+	.remove = mac_mace_device_remove,
+	.driver	= {
+		.name	= mac_mace_string,
+	},
+};
+
+module_platform_driver(mac_mace_driver);