1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Driver for the Macintosh 68K onboard MACE controller with PSC
4  *	driven DMA. The MACE driver code is derived from mace.c. The
5  *	Mac68k theory of operation is courtesy of the MacBSD wizards.
6  *
7  *	Copyright (C) 1996 Paul Mackerras.
8  *	Copyright (C) 1998 Alan Cox <alan@lxorguk.ukuu.org.uk>
9  *
10  *	Modified heavily by Joshua M. Thompson based on Dave Huang's NetBSD driver
11  *
12  *	Copyright (C) 2007 Finn Thain
13  *
14  *	Converted to DMA API, converted to unified driver model,
15  *	sync'd some routines with mace.c and fixed various bugs.
16  */
17 
18 
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23 #include <linux/delay.h>
24 #include <linux/string.h>
25 #include <linux/crc32.h>
26 #include <linux/bitrev.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/platform_device.h>
29 #include <linux/gfp.h>
30 #include <linux/interrupt.h>
31 #include <asm/io.h>
32 #include <asm/macints.h>
33 #include <asm/mac_psc.h>
34 #include <asm/page.h>
35 #include "mace.h"
36 
37 static char mac_mace_string[] = "macmace";
38 
39 #define N_TX_BUFF_ORDER	0
40 #define N_TX_RING	(1 << N_TX_BUFF_ORDER)
41 #define N_RX_BUFF_ORDER	3
42 #define N_RX_RING	(1 << N_RX_BUFF_ORDER)
43 
44 #define TX_TIMEOUT	HZ
45 
46 #define MACE_BUFF_SIZE	0x800
47 
48 /* Chip rev needs workaround on HW & multicast addr change */
49 #define BROKEN_ADDRCHG_REV	0x0941
50 
51 /* The MACE is simply wired down on a Mac68K box */
52 
53 #define MACE_BASE	(void *)(0x50F1C000)
54 #define MACE_PROM	(void *)(0x50F08001)
55 
56 struct mace_data {
57 	volatile struct mace *mace;
58 	unsigned char *tx_ring;
59 	dma_addr_t tx_ring_phys;
60 	unsigned char *rx_ring;
61 	dma_addr_t rx_ring_phys;
62 	int dma_intr;
63 	int rx_slot, rx_tail;
64 	int tx_slot, tx_sloti, tx_count;
65 	int chipid;
66 	struct device *device;
67 };
68 
69 struct mace_frame {
70 	u8	rcvcnt;
71 	u8	pad1;
72 	u8	rcvsts;
73 	u8	pad2;
74 	u8	rntpc;
75 	u8	pad3;
76 	u8	rcvcc;
77 	u8	pad4;
78 	u32	pad5;
79 	u32	pad6;
80 	u8	data[1];
81 	/* And frame continues.. */
82 };
83 
84 #define PRIV_BYTES	sizeof(struct mace_data)
85 
86 static int mace_open(struct net_device *dev);
87 static int mace_close(struct net_device *dev);
88 static netdev_tx_t mace_xmit_start(struct sk_buff *skb, struct net_device *dev);
89 static void mace_set_multicast(struct net_device *dev);
90 static int mace_set_address(struct net_device *dev, void *addr);
91 static void mace_reset(struct net_device *dev);
92 static irqreturn_t mace_interrupt(int irq, void *dev_id);
93 static irqreturn_t mace_dma_intr(int irq, void *dev_id);
94 static void mace_tx_timeout(struct net_device *dev);
95 static void __mace_set_address(struct net_device *dev, void *addr);
96 
97 /*
98  * Load a receive DMA channel with a base address and ring length
99  */
100 
101 static void mace_load_rxdma_base(struct net_device *dev, int set)
102 {
103 	struct mace_data *mp = netdev_priv(dev);
104 
105 	psc_write_word(PSC_ENETRD_CMD + set, 0x0100);
106 	psc_write_long(PSC_ENETRD_ADDR + set, (u32) mp->rx_ring_phys);
107 	psc_write_long(PSC_ENETRD_LEN + set, N_RX_RING);
108 	psc_write_word(PSC_ENETRD_CMD + set, 0x9800);
109 	mp->rx_tail = 0;
110 }
111 
112 /*
113  * Reset the receive DMA subsystem
114  */
115 
116 static void mace_rxdma_reset(struct net_device *dev)
117 {
118 	struct mace_data *mp = netdev_priv(dev);
119 	volatile struct mace *mace = mp->mace;
120 	u8 maccc = mace->maccc;
121 
122 	mace->maccc = maccc & ~ENRCV;
123 
124 	psc_write_word(PSC_ENETRD_CTL, 0x8800);
125 	mace_load_rxdma_base(dev, 0x00);
126 	psc_write_word(PSC_ENETRD_CTL, 0x0400);
127 
128 	psc_write_word(PSC_ENETRD_CTL, 0x8800);
129 	mace_load_rxdma_base(dev, 0x10);
130 	psc_write_word(PSC_ENETRD_CTL, 0x0400);
131 
132 	mace->maccc = maccc;
133 	mp->rx_slot = 0;
134 
135 	psc_write_word(PSC_ENETRD_CMD + PSC_SET0, 0x9800);
136 	psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x9800);
137 }
138 
139 /*
140  * Reset the transmit DMA subsystem
141  */
142 
143 static void mace_txdma_reset(struct net_device *dev)
144 {
145 	struct mace_data *mp = netdev_priv(dev);
146 	volatile struct mace *mace = mp->mace;
147 	u8 maccc;
148 
149 	psc_write_word(PSC_ENETWR_CTL, 0x8800);
150 
151 	maccc = mace->maccc;
152 	mace->maccc = maccc & ~ENXMT;
153 
154 	mp->tx_slot = mp->tx_sloti = 0;
155 	mp->tx_count = N_TX_RING;
156 
157 	psc_write_word(PSC_ENETWR_CTL, 0x0400);
158 	mace->maccc = maccc;
159 }
160 
161 /*
162  * Disable DMA
163  */
164 
165 static void mace_dma_off(struct net_device *dev)
166 {
167 	psc_write_word(PSC_ENETRD_CTL, 0x8800);
168 	psc_write_word(PSC_ENETRD_CTL, 0x1000);
169 	psc_write_word(PSC_ENETRD_CMD + PSC_SET0, 0x1100);
170 	psc_write_word(PSC_ENETRD_CMD + PSC_SET1, 0x1100);
171 
172 	psc_write_word(PSC_ENETWR_CTL, 0x8800);
173 	psc_write_word(PSC_ENETWR_CTL, 0x1000);
174 	psc_write_word(PSC_ENETWR_CMD + PSC_SET0, 0x1100);
175 	psc_write_word(PSC_ENETWR_CMD + PSC_SET1, 0x1100);
176 }
177 
178 static const struct net_device_ops mace_netdev_ops = {
179 	.ndo_open		= mace_open,
180 	.ndo_stop		= mace_close,
181 	.ndo_start_xmit		= mace_xmit_start,
182 	.ndo_tx_timeout		= mace_tx_timeout,
183 	.ndo_set_rx_mode	= mace_set_multicast,
184 	.ndo_set_mac_address	= mace_set_address,
185 	.ndo_validate_addr	= eth_validate_addr,
186 };
187 
188 /*
189  * Not really much of a probe. The hardware table tells us if this
190  * model of Macintrash has a MACE (AV macintoshes)
191  */
192 
193 static int mace_probe(struct platform_device *pdev)
194 {
195 	int j;
196 	struct mace_data *mp;
197 	unsigned char *addr;
198 	struct net_device *dev;
199 	unsigned char checksum = 0;
200 	int err;
201 
202 	dev = alloc_etherdev(PRIV_BYTES);
203 	if (!dev)
204 		return -ENOMEM;
205 
206 	mp = netdev_priv(dev);
207 
208 	mp->device = &pdev->dev;
209 	platform_set_drvdata(pdev, dev);
210 	SET_NETDEV_DEV(dev, &pdev->dev);
211 
212 	dev->base_addr = (u32)MACE_BASE;
213 	mp->mace = MACE_BASE;
214 
215 	dev->irq = IRQ_MAC_MACE;
216 	mp->dma_intr = IRQ_MAC_MACE_DMA;
217 
218 	mp->chipid = mp->mace->chipid_hi << 8 | mp->mace->chipid_lo;
219 
220 	/*
221 	 * The PROM contains 8 bytes which total 0xFF when XOR'd
222 	 * together. Due to the usual peculiar apple brain damage
223 	 * the bytes are spaced out in a strange boundary and the
224 	 * bits are reversed.
225 	 */
226 
227 	addr = MACE_PROM;
228 
229 	for (j = 0; j < 6; ++j) {
230 		u8 v = bitrev8(addr[j<<4]);
231 		checksum ^= v;
232 		dev->dev_addr[j] = v;
233 	}
234 	for (; j < 8; ++j) {
235 		checksum ^= bitrev8(addr[j<<4]);
236 	}
237 
238 	if (checksum != 0xFF) {
239 		free_netdev(dev);
240 		return -ENODEV;
241 	}
242 
243 	dev->netdev_ops		= &mace_netdev_ops;
244 	dev->watchdog_timeo	= TX_TIMEOUT;
245 
246 	pr_info("Onboard MACE, hardware address %pM, chip revision 0x%04X\n",
247 		dev->dev_addr, mp->chipid);
248 
249 	err = register_netdev(dev);
250 	if (!err)
251 		return 0;
252 
253 	free_netdev(dev);
254 	return err;
255 }
256 
257 /*
258  * Reset the chip.
259  */
260 
261 static void mace_reset(struct net_device *dev)
262 {
263 	struct mace_data *mp = netdev_priv(dev);
264 	volatile struct mace *mb = mp->mace;
265 	int i;
266 
267 	/* soft-reset the chip */
268 	i = 200;
269 	while (--i) {
270 		mb->biucc = SWRST;
271 		if (mb->biucc & SWRST) {
272 			udelay(10);
273 			continue;
274 		}
275 		break;
276 	}
277 	if (!i) {
278 		printk(KERN_ERR "macmace: cannot reset chip!\n");
279 		return;
280 	}
281 
282 	mb->maccc = 0;	/* turn off tx, rx */
283 	mb->imr = 0xFF;	/* disable all intrs for now */
284 	i = mb->ir;
285 
286 	mb->biucc = XMTSP_64;
287 	mb->utr = RTRD;
288 	mb->fifocc = XMTFW_8 | RCVFW_64 | XMTFWU | RCVFWU;
289 
290 	mb->xmtfc = AUTO_PAD_XMIT; /* auto-pad short frames */
291 	mb->rcvfc = 0;
292 
293 	/* load up the hardware address */
294 	__mace_set_address(dev, dev->dev_addr);
295 
296 	/* clear the multicast filter */
297 	if (mp->chipid == BROKEN_ADDRCHG_REV)
298 		mb->iac = LOGADDR;
299 	else {
300 		mb->iac = ADDRCHG | LOGADDR;
301 		while ((mb->iac & ADDRCHG) != 0)
302 			;
303 	}
304 	for (i = 0; i < 8; ++i)
305 		mb->ladrf = 0;
306 
307 	/* done changing address */
308 	if (mp->chipid != BROKEN_ADDRCHG_REV)
309 		mb->iac = 0;
310 
311 	mb->plscc = PORTSEL_AUI;
312 }
313 
314 /*
315  * Load the address on a mace controller.
316  */
317 
318 static void __mace_set_address(struct net_device *dev, void *addr)
319 {
320 	struct mace_data *mp = netdev_priv(dev);
321 	volatile struct mace *mb = mp->mace;
322 	unsigned char *p = addr;
323 	int i;
324 
325 	/* load up the hardware address */
326 	if (mp->chipid == BROKEN_ADDRCHG_REV)
327 		mb->iac = PHYADDR;
328 	else {
329 		mb->iac = ADDRCHG | PHYADDR;
330 		while ((mb->iac & ADDRCHG) != 0)
331 			;
332 	}
333 	for (i = 0; i < 6; ++i)
334 		mb->padr = dev->dev_addr[i] = p[i];
335 	if (mp->chipid != BROKEN_ADDRCHG_REV)
336 		mb->iac = 0;
337 }
338 
339 static int mace_set_address(struct net_device *dev, void *addr)
340 {
341 	struct mace_data *mp = netdev_priv(dev);
342 	volatile struct mace *mb = mp->mace;
343 	unsigned long flags;
344 	u8 maccc;
345 
346 	local_irq_save(flags);
347 
348 	maccc = mb->maccc;
349 
350 	__mace_set_address(dev, addr);
351 
352 	mb->maccc = maccc;
353 
354 	local_irq_restore(flags);
355 
356 	return 0;
357 }
358 
359 /*
360  * Open the Macintosh MACE. Most of this is playing with the DMA
361  * engine. The ethernet chip is quite friendly.
362  */
363 
364 static int mace_open(struct net_device *dev)
365 {
366 	struct mace_data *mp = netdev_priv(dev);
367 	volatile struct mace *mb = mp->mace;
368 
369 	/* reset the chip */
370 	mace_reset(dev);
371 
372 	if (request_irq(dev->irq, mace_interrupt, 0, dev->name, dev)) {
373 		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, dev->irq);
374 		return -EAGAIN;
375 	}
376 	if (request_irq(mp->dma_intr, mace_dma_intr, 0, dev->name, dev)) {
377 		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, mp->dma_intr);
378 		free_irq(dev->irq, dev);
379 		return -EAGAIN;
380 	}
381 
382 	/* Allocate the DMA ring buffers */
383 
384 	mp->tx_ring = dma_alloc_coherent(mp->device,
385 					 N_TX_RING * MACE_BUFF_SIZE,
386 					 &mp->tx_ring_phys, GFP_KERNEL);
387 	if (mp->tx_ring == NULL)
388 		goto out1;
389 
390 	mp->rx_ring = dma_alloc_coherent(mp->device,
391 					 N_RX_RING * MACE_BUFF_SIZE,
392 					 &mp->rx_ring_phys, GFP_KERNEL);
393 	if (mp->rx_ring == NULL)
394 		goto out2;
395 
396 	mace_dma_off(dev);
397 
398 	/* Not sure what these do */
399 
400 	psc_write_word(PSC_ENETWR_CTL, 0x9000);
401 	psc_write_word(PSC_ENETRD_CTL, 0x9000);
402 	psc_write_word(PSC_ENETWR_CTL, 0x0400);
403 	psc_write_word(PSC_ENETRD_CTL, 0x0400);
404 
405 	mace_rxdma_reset(dev);
406 	mace_txdma_reset(dev);
407 
408 	/* turn it on! */
409 	mb->maccc = ENXMT | ENRCV;
410 	/* enable all interrupts except receive interrupts */
411 	mb->imr = RCVINT;
412 	return 0;
413 
414 out2:
415 	dma_free_coherent(mp->device, N_TX_RING * MACE_BUFF_SIZE,
416 	                  mp->tx_ring, mp->tx_ring_phys);
417 out1:
418 	free_irq(dev->irq, dev);
419 	free_irq(mp->dma_intr, dev);
420 	return -ENOMEM;
421 }
422 
423 /*
424  * Shut down the mace and its interrupt channel
425  */
426 
427 static int mace_close(struct net_device *dev)
428 {
429 	struct mace_data *mp = netdev_priv(dev);
430 	volatile struct mace *mb = mp->mace;
431 
432 	mb->maccc = 0;		/* disable rx and tx	 */
433 	mb->imr = 0xFF;		/* disable all irqs	 */
434 	mace_dma_off(dev);	/* disable rx and tx dma */
435 
436 	return 0;
437 }
438 
439 /*
440  * Transmit a frame
441  */
442 
443 static netdev_tx_t mace_xmit_start(struct sk_buff *skb, struct net_device *dev)
444 {
445 	struct mace_data *mp = netdev_priv(dev);
446 	unsigned long flags;
447 
448 	/* Stop the queue since there's only the one buffer */
449 
450 	local_irq_save(flags);
451 	netif_stop_queue(dev);
452 	if (!mp->tx_count) {
453 		printk(KERN_ERR "macmace: tx queue running but no free buffers.\n");
454 		local_irq_restore(flags);
455 		return NETDEV_TX_BUSY;
456 	}
457 	mp->tx_count--;
458 	local_irq_restore(flags);
459 
460 	dev->stats.tx_packets++;
461 	dev->stats.tx_bytes += skb->len;
462 
463 	/* We need to copy into our xmit buffer to take care of alignment and caching issues */
464 	skb_copy_from_linear_data(skb, mp->tx_ring, skb->len);
465 
466 	/* load the Tx DMA and fire it off */
467 
468 	psc_write_long(PSC_ENETWR_ADDR + mp->tx_slot, (u32)  mp->tx_ring_phys);
469 	psc_write_long(PSC_ENETWR_LEN + mp->tx_slot, skb->len);
470 	psc_write_word(PSC_ENETWR_CMD + mp->tx_slot, 0x9800);
471 
472 	mp->tx_slot ^= 0x10;
473 
474 	dev_kfree_skb(skb);
475 
476 	return NETDEV_TX_OK;
477 }
478 
479 static void mace_set_multicast(struct net_device *dev)
480 {
481 	struct mace_data *mp = netdev_priv(dev);
482 	volatile struct mace *mb = mp->mace;
483 	int i;
484 	u32 crc;
485 	u8 maccc;
486 	unsigned long flags;
487 
488 	local_irq_save(flags);
489 	maccc = mb->maccc;
490 	mb->maccc &= ~PROM;
491 
492 	if (dev->flags & IFF_PROMISC) {
493 		mb->maccc |= PROM;
494 	} else {
495 		unsigned char multicast_filter[8];
496 		struct netdev_hw_addr *ha;
497 
498 		if (dev->flags & IFF_ALLMULTI) {
499 			for (i = 0; i < 8; i++) {
500 				multicast_filter[i] = 0xFF;
501 			}
502 		} else {
503 			for (i = 0; i < 8; i++)
504 				multicast_filter[i] = 0;
505 			netdev_for_each_mc_addr(ha, dev) {
506 				crc = ether_crc_le(6, ha->addr);
507 				/* bit number in multicast_filter */
508 				i = crc >> 26;
509 				multicast_filter[i >> 3] |= 1 << (i & 7);
510 			}
511 		}
512 
513 		if (mp->chipid == BROKEN_ADDRCHG_REV)
514 			mb->iac = LOGADDR;
515 		else {
516 			mb->iac = ADDRCHG | LOGADDR;
517 			while ((mb->iac & ADDRCHG) != 0)
518 				;
519 		}
520 		for (i = 0; i < 8; ++i)
521 			mb->ladrf = multicast_filter[i];
522 		if (mp->chipid != BROKEN_ADDRCHG_REV)
523 			mb->iac = 0;
524 	}
525 
526 	mb->maccc = maccc;
527 	local_irq_restore(flags);
528 }
529 
530 static void mace_handle_misc_intrs(struct net_device *dev, int intr)
531 {
532 	struct mace_data *mp = netdev_priv(dev);
533 	volatile struct mace *mb = mp->mace;
534 	static int mace_babbles, mace_jabbers;
535 
536 	if (intr & MPCO)
537 		dev->stats.rx_missed_errors += 256;
538 	dev->stats.rx_missed_errors += mb->mpc;   /* reading clears it */
539 	if (intr & RNTPCO)
540 		dev->stats.rx_length_errors += 256;
541 	dev->stats.rx_length_errors += mb->rntpc; /* reading clears it */
542 	if (intr & CERR)
543 		++dev->stats.tx_heartbeat_errors;
544 	if (intr & BABBLE)
545 		if (mace_babbles++ < 4)
546 			printk(KERN_DEBUG "macmace: babbling transmitter\n");
547 	if (intr & JABBER)
548 		if (mace_jabbers++ < 4)
549 			printk(KERN_DEBUG "macmace: jabbering transceiver\n");
550 }
551 
552 static irqreturn_t mace_interrupt(int irq, void *dev_id)
553 {
554 	struct net_device *dev = (struct net_device *) dev_id;
555 	struct mace_data *mp = netdev_priv(dev);
556 	volatile struct mace *mb = mp->mace;
557 	int intr, fs;
558 	unsigned long flags;
559 
560 	/* don't want the dma interrupt handler to fire */
561 	local_irq_save(flags);
562 
563 	intr = mb->ir; /* read interrupt register */
564 	mace_handle_misc_intrs(dev, intr);
565 
566 	if (intr & XMTINT) {
567 		fs = mb->xmtfs;
568 		if ((fs & XMTSV) == 0) {
569 			printk(KERN_ERR "macmace: xmtfs not valid! (fs=%x)\n", fs);
570 			mace_reset(dev);
571 			/*
572 			 * XXX mace likes to hang the machine after a xmtfs error.
573 			 * This is hard to reproduce, resetting *may* help
574 			 */
575 		}
576 		/* dma should have finished */
577 		if (!mp->tx_count) {
578 			printk(KERN_DEBUG "macmace: tx ring ran out? (fs=%x)\n", fs);
579 		}
580 		/* Update stats */
581 		if (fs & (UFLO|LCOL|LCAR|RTRY)) {
582 			++dev->stats.tx_errors;
583 			if (fs & LCAR)
584 				++dev->stats.tx_carrier_errors;
585 			else if (fs & (UFLO|LCOL|RTRY)) {
586 				++dev->stats.tx_aborted_errors;
587 				if (mb->xmtfs & UFLO) {
588 					dev->stats.tx_fifo_errors++;
589 					mace_txdma_reset(dev);
590 				}
591 			}
592 		}
593 	}
594 
595 	if (mp->tx_count)
596 		netif_wake_queue(dev);
597 
598 	local_irq_restore(flags);
599 
600 	return IRQ_HANDLED;
601 }
602 
603 static void mace_tx_timeout(struct net_device *dev)
604 {
605 	struct mace_data *mp = netdev_priv(dev);
606 	volatile struct mace *mb = mp->mace;
607 	unsigned long flags;
608 
609 	local_irq_save(flags);
610 
611 	/* turn off both tx and rx and reset the chip */
612 	mb->maccc = 0;
613 	printk(KERN_ERR "macmace: transmit timeout - resetting\n");
614 	mace_txdma_reset(dev);
615 	mace_reset(dev);
616 
617 	/* restart rx dma */
618 	mace_rxdma_reset(dev);
619 
620 	mp->tx_count = N_TX_RING;
621 	netif_wake_queue(dev);
622 
623 	/* turn it on! */
624 	mb->maccc = ENXMT | ENRCV;
625 	/* enable all interrupts except receive interrupts */
626 	mb->imr = RCVINT;
627 
628 	local_irq_restore(flags);
629 }
630 
631 /*
632  * Handle a newly arrived frame
633  */
634 
635 static void mace_dma_rx_frame(struct net_device *dev, struct mace_frame *mf)
636 {
637 	struct sk_buff *skb;
638 	unsigned int frame_status = mf->rcvsts;
639 
640 	if (frame_status & (RS_OFLO | RS_CLSN | RS_FRAMERR | RS_FCSERR)) {
641 		dev->stats.rx_errors++;
642 		if (frame_status & RS_OFLO)
643 			dev->stats.rx_fifo_errors++;
644 		if (frame_status & RS_CLSN)
645 			dev->stats.collisions++;
646 		if (frame_status & RS_FRAMERR)
647 			dev->stats.rx_frame_errors++;
648 		if (frame_status & RS_FCSERR)
649 			dev->stats.rx_crc_errors++;
650 	} else {
651 		unsigned int frame_length = mf->rcvcnt + ((frame_status & 0x0F) << 8 );
652 
653 		skb = netdev_alloc_skb(dev, frame_length + 2);
654 		if (!skb) {
655 			dev->stats.rx_dropped++;
656 			return;
657 		}
658 		skb_reserve(skb, 2);
659 		skb_put_data(skb, mf->data, frame_length);
660 
661 		skb->protocol = eth_type_trans(skb, dev);
662 		netif_rx(skb);
663 		dev->stats.rx_packets++;
664 		dev->stats.rx_bytes += frame_length;
665 	}
666 }
667 
668 /*
669  * The PSC has passed us a DMA interrupt event.
670  */
671 
672 static irqreturn_t mace_dma_intr(int irq, void *dev_id)
673 {
674 	struct net_device *dev = (struct net_device *) dev_id;
675 	struct mace_data *mp = netdev_priv(dev);
676 	int left, head;
677 	u16 status;
678 	u32 baka;
679 
680 	/* Not sure what this does */
681 
682 	while ((baka = psc_read_long(PSC_MYSTERY)) != psc_read_long(PSC_MYSTERY));
683 	if (!(baka & 0x60000000)) return IRQ_NONE;
684 
685 	/*
686 	 * Process the read queue
687 	 */
688 
689 	status = psc_read_word(PSC_ENETRD_CTL);
690 
691 	if (status & 0x2000) {
692 		mace_rxdma_reset(dev);
693 	} else if (status & 0x0100) {
694 		psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x1100);
695 
696 		left = psc_read_long(PSC_ENETRD_LEN + mp->rx_slot);
697 		head = N_RX_RING - left;
698 
699 		/* Loop through the ring buffer and process new packages */
700 
701 		while (mp->rx_tail < head) {
702 			mace_dma_rx_frame(dev, (struct mace_frame*) (mp->rx_ring
703 				+ (mp->rx_tail * MACE_BUFF_SIZE)));
704 			mp->rx_tail++;
705 		}
706 
707 		/* If we're out of buffers in this ring then switch to */
708 		/* the other set, otherwise just reactivate this one.  */
709 
710 		if (!left) {
711 			mace_load_rxdma_base(dev, mp->rx_slot);
712 			mp->rx_slot ^= 0x10;
713 		} else {
714 			psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x9800);
715 		}
716 	}
717 
718 	/*
719 	 * Process the write queue
720 	 */
721 
722 	status = psc_read_word(PSC_ENETWR_CTL);
723 
724 	if (status & 0x2000) {
725 		mace_txdma_reset(dev);
726 	} else if (status & 0x0100) {
727 		psc_write_word(PSC_ENETWR_CMD + mp->tx_sloti, 0x0100);
728 		mp->tx_sloti ^= 0x10;
729 		mp->tx_count++;
730 	}
731 	return IRQ_HANDLED;
732 }
733 
734 MODULE_LICENSE("GPL");
735 MODULE_DESCRIPTION("Macintosh MACE ethernet driver");
736 MODULE_ALIAS("platform:macmace");
737 
738 static int mac_mace_device_remove(struct platform_device *pdev)
739 {
740 	struct net_device *dev = platform_get_drvdata(pdev);
741 	struct mace_data *mp = netdev_priv(dev);
742 
743 	unregister_netdev(dev);
744 
745 	free_irq(dev->irq, dev);
746 	free_irq(IRQ_MAC_MACE_DMA, dev);
747 
748 	dma_free_coherent(mp->device, N_RX_RING * MACE_BUFF_SIZE,
749 	                  mp->rx_ring, mp->rx_ring_phys);
750 	dma_free_coherent(mp->device, N_TX_RING * MACE_BUFF_SIZE,
751 	                  mp->tx_ring, mp->tx_ring_phys);
752 
753 	free_netdev(dev);
754 
755 	return 0;
756 }
757 
758 static struct platform_driver mac_mace_driver = {
759 	.probe  = mace_probe,
760 	.remove = mac_mace_device_remove,
761 	.driver	= {
762 		.name	= mac_mace_string,
763 	},
764 };
765 
766 module_platform_driver(mac_mace_driver);
767