1 /*
2  *	Driver for the Macintosh 68K onboard MACE controller with PSC
3  *	driven DMA. The MACE driver code is derived from mace.c. The
4  *	Mac68k theory of operation is courtesy of the MacBSD wizards.
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  *
11  *	Copyright (C) 1996 Paul Mackerras.
12  *	Copyright (C) 1998 Alan Cox <alan@redhat.com>
13  *
14  *	Modified heavily by Joshua M. Thompson based on Dave Huang's NetBSD driver
15  */
16 
17 
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/delay.h>
23 #include <linux/string.h>
24 #include <linux/crc32.h>
25 #include <asm/io.h>
26 #include <asm/pgtable.h>
27 #include <asm/irq.h>
28 #include <asm/macintosh.h>
29 #include <asm/macints.h>
30 #include <asm/mac_psc.h>
31 #include <asm/page.h>
32 #include "mace.h"
33 
34 #define N_TX_RING	1
35 #define N_RX_RING	8
36 #define N_RX_PAGES	((N_RX_RING * 0x0800 + PAGE_SIZE - 1) / PAGE_SIZE)
37 #define TX_TIMEOUT	HZ
38 
39 /* Bits in transmit DMA status */
40 #define TX_DMA_ERR	0x80
41 
42 /* The MACE is simply wired down on a Mac68K box */
43 
44 #define MACE_BASE	(void *)(0x50F1C000)
45 #define MACE_PROM	(void *)(0x50F08001)
46 
47 struct mace_data {
48 	volatile struct mace *mace;
49 	volatile unsigned char *tx_ring;
50 	volatile unsigned char *tx_ring_phys;
51 	volatile unsigned char *rx_ring;
52 	volatile unsigned char *rx_ring_phys;
53 	int dma_intr;
54 	struct net_device_stats stats;
55 	int rx_slot, rx_tail;
56 	int tx_slot, tx_sloti, tx_count;
57 };
58 
59 struct mace_frame {
60 	u16	len;
61 	u16	status;
62 	u16	rntpc;
63 	u16	rcvcc;
64 	u32	pad1;
65 	u32	pad2;
66 	u8	data[1];
67 	/* And frame continues.. */
68 };
69 
70 #define PRIV_BYTES	sizeof(struct mace_data)
71 
72 extern void psc_debug_dump(void);
73 
74 static int mace_open(struct net_device *dev);
75 static int mace_close(struct net_device *dev);
76 static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev);
77 static struct net_device_stats *mace_stats(struct net_device *dev);
78 static void mace_set_multicast(struct net_device *dev);
79 static int mace_set_address(struct net_device *dev, void *addr);
80 static void mace_interrupt(int irq, void *dev_id, struct pt_regs *regs);
81 static void mace_dma_intr(int irq, void *dev_id, struct pt_regs *regs);
82 static void mace_tx_timeout(struct net_device *dev);
83 
84 /* Bit-reverse one byte of an ethernet hardware address. */
85 
bitrev(int b)86 static int bitrev(int b)
87 {
88 	int d = 0, i;
89 
90 	for (i = 0; i < 8; ++i, b >>= 1) {
91 		d = (d << 1) | (b & 1);
92 	}
93 
94 	return d;
95 }
96 
97 /*
98  * Load a receive DMA channel with a base address and ring length
99  */
100 
mace_load_rxdma_base(struct net_device * dev,int set)101 static void mace_load_rxdma_base(struct net_device *dev, int set)
102 {
103 	struct mace_data *mp = (struct mace_data *) dev->priv;
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 
mace_rxdma_reset(struct net_device * dev)116 static void mace_rxdma_reset(struct net_device *dev)
117 {
118 	struct mace_data *mp = (struct mace_data *) dev->priv;
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 
mace_txdma_reset(struct net_device * dev)143 static void mace_txdma_reset(struct net_device *dev)
144 {
145 	struct mace_data *mp = (struct mace_data *) dev->priv;
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 
mace_dma_off(struct net_device * dev)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 /*
179  * Not really much of a probe. The hardware table tells us if this
180  * model of Macintrash has a MACE (AV macintoshes)
181  */
182 
mace_probe(struct net_device * unused)183 int mace_probe(struct net_device *unused)
184 {
185 	int j;
186 	struct mace_data *mp;
187 	unsigned char *addr;
188 	struct net_device *dev;
189 	unsigned char checksum = 0;
190 	static int found = 0;
191 
192 	if (found || macintosh_config->ether_type != MAC_ETHER_MACE) return -ENODEV;
193 
194 	found = 1;	/* prevent 'finding' one on every device probe */
195 
196 	dev = init_etherdev(0, PRIV_BYTES);
197 	if (!dev) return -ENOMEM;
198 
199 	mp = (struct mace_data *) dev->priv;
200 	dev->base_addr = (u32)MACE_BASE;
201 	mp->mace = (volatile struct mace *) MACE_BASE;
202 
203 	dev->irq = IRQ_MAC_MACE;
204 	mp->dma_intr = IRQ_MAC_MACE_DMA;
205 
206 	/*
207 	 * The PROM contains 8 bytes which total 0xFF when XOR'd
208 	 * together. Due to the usual peculiar apple brain damage
209 	 * the bytes are spaced out in a strange boundary and the
210 	 * bits are reversed.
211 	 */
212 
213 	addr = (void *)MACE_PROM;
214 
215 	for (j = 0; j < 6; ++j) {
216 		u8 v=bitrev(addr[j<<4]);
217 		checksum ^= v;
218 		dev->dev_addr[j] = v;
219 	}
220 	for (; j < 8; ++j) {
221 		checksum ^= bitrev(addr[j<<4]);
222 	}
223 
224 	if (checksum != 0xFF) return -ENODEV;
225 
226 	memset(&mp->stats, 0, sizeof(mp->stats));
227 
228 	dev->open		= mace_open;
229 	dev->stop		= mace_close;
230 	dev->hard_start_xmit	= mace_xmit_start;
231 	dev->tx_timeout		= mace_tx_timeout;
232 	dev->watchdog_timeo	= TX_TIMEOUT;
233 	dev->get_stats		= mace_stats;
234 	dev->set_multicast_list	= mace_set_multicast;
235 	dev->set_mac_address	= mace_set_address;
236 
237 	ether_setup(dev);
238 
239 	printk(KERN_INFO "%s: 68K MACE, hardware address %.2X", dev->name, dev->dev_addr[0]);
240 	for (j = 1 ; j < 6 ; j++) printk(":%.2X", dev->dev_addr[j]);
241 	printk("\n");
242 
243 	return 0;
244 }
245 
246 /*
247  * Load the address on a mace controller.
248  */
249 
mace_set_address(struct net_device * dev,void * addr)250 static int mace_set_address(struct net_device *dev, void *addr)
251 {
252 	unsigned char *p = addr;
253 	struct mace_data *mp = (struct mace_data *) dev->priv;
254 	volatile struct mace *mb = mp->mace;
255 	int i;
256 	unsigned long flags;
257 	u8 maccc;
258 
259 	save_flags(flags);
260 	cli();
261 
262 	maccc = mb->maccc;
263 
264 	/* load up the hardware address */
265 	mb->iac = ADDRCHG | PHYADDR;
266 	while ((mb->iac & ADDRCHG) != 0);
267 
268 	for (i = 0; i < 6; ++i) {
269 		mb->padr = dev->dev_addr[i] = p[i];
270 	}
271 
272 	mb->maccc = maccc;
273 	restore_flags(flags);
274 
275 	return 0;
276 }
277 
278 /*
279  * Open the Macintosh MACE. Most of this is playing with the DMA
280  * engine. The ethernet chip is quite friendly.
281  */
282 
mace_open(struct net_device * dev)283 static int mace_open(struct net_device *dev)
284 {
285 	struct mace_data *mp = (struct mace_data *) dev->priv;
286 	volatile struct mace *mb = mp->mace;
287 #if 0
288 	int i;
289 
290 	i = 200;
291 	while (--i) {
292 		mb->biucc = SWRST;
293 		if (mb->biucc & SWRST) {
294 			udelay(10);
295 			continue;
296 		}
297 		break;
298 	}
299 	if (!i) {
300 		printk(KERN_ERR "%s: software reset failed!!\n", dev->name);
301 		return -EAGAIN;
302 	}
303 #endif
304 
305 	mb->biucc = XMTSP_64;
306 	mb->fifocc = XMTFW_16 | RCVFW_64 | XMTFWU | RCVFWU | XMTBRST | RCVBRST;
307 	mb->xmtfc = AUTO_PAD_XMIT;
308 	mb->plscc = PORTSEL_AUI;
309 	/* mb->utr = RTRD; */
310 
311 	if (request_irq(dev->irq, mace_interrupt, 0, dev->name, dev)) {
312 		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, dev->irq);
313 		return -EAGAIN;
314 	}
315 	if (request_irq(mp->dma_intr, mace_dma_intr, 0, dev->name, dev)) {
316 		printk(KERN_ERR "%s: can't get irq %d\n", dev->name, mp->dma_intr);
317 		free_irq(dev->irq, dev);
318 		return -EAGAIN;
319 	}
320 
321 	/* Allocate the DMA ring buffers */
322 
323 	mp->rx_ring = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, N_RX_PAGES);
324 	mp->tx_ring = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, 0);
325 
326 	if (mp->tx_ring==NULL || mp->rx_ring==NULL) {
327 		if (mp->rx_ring) free_pages((u32) mp->rx_ring, N_RX_PAGES);
328 		if (mp->tx_ring) free_pages((u32) mp->tx_ring, 0);
329 		free_irq(dev->irq, dev);
330 		free_irq(mp->dma_intr, dev);
331 		printk(KERN_ERR "%s: unable to allocate DMA buffers\n", dev->name);
332 		return -ENOMEM;
333 	}
334 
335 	mp->rx_ring_phys = (unsigned char *) virt_to_bus((void *)mp->rx_ring);
336 	mp->tx_ring_phys = (unsigned char *) virt_to_bus((void *)mp->tx_ring);
337 
338 	/* We want the Rx buffer to be uncached and the Tx buffer to be writethrough */
339 
340 	kernel_set_cachemode((void *)mp->rx_ring, N_RX_PAGES * PAGE_SIZE, IOMAP_NOCACHE_NONSER);
341 	kernel_set_cachemode((void *)mp->tx_ring, PAGE_SIZE, IOMAP_WRITETHROUGH);
342 
343 	mace_dma_off(dev);
344 
345 	/* Not sure what these do */
346 
347 	psc_write_word(PSC_ENETWR_CTL, 0x9000);
348 	psc_write_word(PSC_ENETRD_CTL, 0x9000);
349 	psc_write_word(PSC_ENETWR_CTL, 0x0400);
350 	psc_write_word(PSC_ENETRD_CTL, 0x0400);
351 
352 #if 0
353 	/* load up the hardware address */
354 
355 	mb->iac = ADDRCHG | PHYADDR;
356 
357 	while ((mb->iac & ADDRCHG) != 0);
358 
359 	for (i = 0; i < 6; ++i)
360 		mb->padr = dev->dev_addr[i];
361 
362 	/* clear the multicast filter */
363 	mb->iac = ADDRCHG | LOGADDR;
364 
365 	while ((mb->iac & ADDRCHG) != 0);
366 
367 	for (i = 0; i < 8; ++i)
368 		mb->ladrf = 0;
369 
370 	mb->plscc = PORTSEL_GPSI + ENPLSIO;
371 
372 	mb->maccc = ENXMT | ENRCV;
373 	mb->imr = RCVINT;
374 #endif
375 
376 	mace_rxdma_reset(dev);
377 	mace_txdma_reset(dev);
378 
379 	return 0;
380 }
381 
382 /*
383  * Shut down the mace and its interrupt channel
384  */
385 
mace_close(struct net_device * dev)386 static int mace_close(struct net_device *dev)
387 {
388 	struct mace_data *mp = (struct mace_data *) dev->priv;
389 	volatile struct mace *mb = mp->mace;
390 
391 	mb->maccc = 0;		/* disable rx and tx	 */
392 	mb->imr = 0xFF;		/* disable all irqs	 */
393 	mace_dma_off(dev);	/* disable rx and tx dma */
394 
395 	free_irq(dev->irq, dev);
396 	free_irq(IRQ_MAC_MACE_DMA, dev);
397 
398 	free_pages((u32) mp->rx_ring, N_RX_PAGES);
399 	free_pages((u32) mp->tx_ring, 0);
400 
401 	return 0;
402 }
403 
404 /*
405  * Transmit a frame
406  */
407 
mace_xmit_start(struct sk_buff * skb,struct net_device * dev)408 static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev)
409 {
410 	struct mace_data *mp = (struct mace_data *) dev->priv;
411 
412 	/* Stop the queue if the buffer is full */
413 
414 	if (!mp->tx_count) {
415 		netif_stop_queue(dev);
416 		return 1;
417 	}
418 	mp->tx_count--;
419 
420 	mp->stats.tx_packets++;
421 	mp->stats.tx_bytes += skb->len;
422 
423 	/* We need to copy into our xmit buffer to take care of alignment and caching issues */
424 
425 	memcpy((void *) mp->tx_ring, skb->data, skb->len);
426 
427 	/* load the Tx DMA and fire it off */
428 
429 	psc_write_long(PSC_ENETWR_ADDR + mp->tx_slot, (u32)  mp->tx_ring_phys);
430 	psc_write_long(PSC_ENETWR_LEN + mp->tx_slot, skb->len);
431 	psc_write_word(PSC_ENETWR_CMD + mp->tx_slot, 0x9800);
432 
433 	mp->tx_slot ^= 0x10;
434 
435 	dev_kfree_skb(skb);
436 
437 	return 0;
438 }
439 
mace_stats(struct net_device * dev)440 static struct net_device_stats *mace_stats(struct net_device *dev)
441 {
442 	struct mace_data *p = (struct mace_data *) dev->priv;
443 	return &p->stats;
444 }
445 
mace_set_multicast(struct net_device * dev)446 static void mace_set_multicast(struct net_device *dev)
447 {
448 	struct mace_data *mp = (struct mace_data *) dev->priv;
449 	volatile struct mace *mb = mp->mace;
450 	int i, j;
451 	u32 crc;
452 	u8 maccc;
453 
454 	maccc = mb->maccc;
455 	mb->maccc &= ~PROM;
456 
457 	if (dev->flags & IFF_PROMISC) {
458 		mb->maccc |= PROM;
459 	} else {
460 		unsigned char multicast_filter[8];
461 		struct dev_mc_list *dmi = dev->mc_list;
462 
463 		if (dev->flags & IFF_ALLMULTI) {
464 			for (i = 0; i < 8; i++) {
465 				multicast_filter[i] = 0xFF;
466 			}
467 		} else {
468 			for (i = 0; i < 8; i++) {
469 				multicast_filter[i] = 0;
470 			}
471 			for (i = 0; i < dev->mc_count; i++) {
472 				crc = ether_crc_le(6, dmi->dmi_addr);
473 				j = crc >> 26;	/* bit number in multicast_filter */
474 				multicast_filter[j >> 3] |= 1 << (j & 7);
475 				dmi = dmi->next;
476 			}
477 		}
478 
479 		mb->iac = ADDRCHG | LOGADDR;
480 		while (mb->iac & ADDRCHG);
481 
482 		for (i = 0; i < 8; ++i) {
483 			mb->ladrf = multicast_filter[i];
484 		}
485 	}
486 
487 	mb->maccc = maccc;
488 }
489 
490 /*
491  * Miscellaneous interrupts are handled here. We may end up
492  * having to bash the chip on the head for bad errors
493  */
494 
mace_handle_misc_intrs(struct mace_data * mp,int intr)495 static void mace_handle_misc_intrs(struct mace_data *mp, int intr)
496 {
497 	volatile struct mace *mb = mp->mace;
498 	static int mace_babbles, mace_jabbers;
499 
500 	if (intr & MPCO) {
501 		mp->stats.rx_missed_errors += 256;
502 	}
503 	mp->stats.rx_missed_errors += mb->mpc;	/* reading clears it */
504 
505 	if (intr & RNTPCO) {
506 		mp->stats.rx_length_errors += 256;
507 	}
508 	mp->stats.rx_length_errors += mb->rntpc;	/* reading clears it */
509 
510 	if (intr & CERR) {
511 		++mp->stats.tx_heartbeat_errors;
512 	}
513 	if (intr & BABBLE) {
514 		if (mace_babbles++ < 4) {
515 			printk(KERN_DEBUG "mace: babbling transmitter\n");
516 		}
517 	}
518 	if (intr & JABBER) {
519 		if (mace_jabbers++ < 4) {
520 			printk(KERN_DEBUG "mace: jabbering transceiver\n");
521 		}
522 	}
523 }
524 
525 /*
526  *	A transmit error has occurred. (We kick the transmit side from
527  *	the DMA completion)
528  */
529 
mace_xmit_error(struct net_device * dev)530 static void mace_xmit_error(struct net_device *dev)
531 {
532 	struct mace_data *mp = (struct mace_data *) dev->priv;
533 	volatile struct mace *mb = mp->mace;
534 	u8 xmtfs, xmtrc;
535 
536 	xmtfs = mb->xmtfs;
537 	xmtrc = mb->xmtrc;
538 
539 	if (xmtfs & XMTSV) {
540 		if (xmtfs & UFLO) {
541 			printk("%s: DMA underrun.\n", dev->name);
542 			mp->stats.tx_errors++;
543 			mp->stats.tx_fifo_errors++;
544 			mace_txdma_reset(dev);
545 		}
546 		if (xmtfs & RTRY) {
547 			mp->stats.collisions++;
548 		}
549 	}
550 }
551 
552 /*
553  *	A receive interrupt occurred.
554  */
555 
mace_recv_interrupt(struct net_device * dev)556 static void mace_recv_interrupt(struct net_device *dev)
557 {
558 /*	struct mace_data *mp = (struct mace_data *) dev->priv; */
559 //	volatile struct mace *mb = mp->mace;
560 }
561 
562 /*
563  * Process the chip interrupt
564  */
565 
mace_interrupt(int irq,void * dev_id,struct pt_regs * regs)566 static void mace_interrupt(int irq, void *dev_id, struct pt_regs *regs)
567 {
568 	struct net_device *dev = (struct net_device *) dev_id;
569 	struct mace_data *mp = (struct mace_data *) dev->priv;
570 	volatile struct mace *mb = mp->mace;
571 	u8 ir;
572 
573 	ir = mb->ir;
574 	mace_handle_misc_intrs(mp, ir);
575 
576 	if (ir & XMTINT) {
577 		mace_xmit_error(dev);
578 	}
579 	if (ir & RCVINT) {
580 		mace_recv_interrupt(dev);
581 	}
582 }
583 
mace_tx_timeout(struct net_device * dev)584 static void mace_tx_timeout(struct net_device *dev)
585 {
586 /*	struct mace_data *mp = (struct mace_data *) dev->priv; */
587 //	volatile struct mace *mb = mp->mace;
588 }
589 
590 /*
591  * Handle a newly arrived frame
592  */
593 
mace_dma_rx_frame(struct net_device * dev,struct mace_frame * mf)594 static void mace_dma_rx_frame(struct net_device *dev, struct mace_frame *mf)
595 {
596 	struct mace_data *mp = (struct mace_data *) dev->priv;
597 	struct sk_buff *skb;
598 
599 	if (mf->status & RS_OFLO) {
600 		printk("%s: fifo overflow.\n", dev->name);
601 		mp->stats.rx_errors++;
602 		mp->stats.rx_fifo_errors++;
603 	}
604 	if (mf->status&(RS_CLSN|RS_FRAMERR|RS_FCSERR))
605 		mp->stats.rx_errors++;
606 
607 	if (mf->status&RS_CLSN) {
608 		mp->stats.collisions++;
609 	}
610 	if (mf->status&RS_FRAMERR) {
611 		mp->stats.rx_frame_errors++;
612 	}
613 	if (mf->status&RS_FCSERR) {
614 		mp->stats.rx_crc_errors++;
615 	}
616 
617 	skb = dev_alloc_skb(mf->len+2);
618 	if (!skb) {
619 		mp->stats.rx_dropped++;
620 		return;
621 	}
622 	skb_reserve(skb,2);
623 	memcpy(skb_put(skb, mf->len), mf->data, mf->len);
624 
625 	skb->dev = dev;
626 	skb->protocol = eth_type_trans(skb, dev);
627 	netif_rx(skb);
628 	dev->last_rx = jiffies;
629 	mp->stats.rx_packets++;
630 	mp->stats.rx_bytes += mf->len;
631 }
632 
633 /*
634  * The PSC has passed us a DMA interrupt event.
635  */
636 
mace_dma_intr(int irq,void * dev_id,struct pt_regs * regs)637 static void mace_dma_intr(int irq, void *dev_id, struct pt_regs *regs)
638 {
639 	struct net_device *dev = (struct net_device *) dev_id;
640 	struct mace_data *mp = (struct mace_data *) dev->priv;
641 	int left, head;
642 	u16 status;
643 	u32 baka;
644 
645 	/* Not sure what this does */
646 
647 	while ((baka = psc_read_long(PSC_MYSTERY)) != psc_read_long(PSC_MYSTERY));
648 	if (!(baka & 0x60000000)) return;
649 
650 	/*
651 	 * Process the read queue
652 	 */
653 
654 	status = psc_read_word(PSC_ENETRD_CTL);
655 
656 	if (status & 0x2000) {
657 		mace_rxdma_reset(dev);
658 	} else if (status & 0x0100) {
659 		psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x1100);
660 
661 		left = psc_read_long(PSC_ENETRD_LEN + mp->rx_slot);
662 		head = N_RX_RING - left;
663 
664 		/* Loop through the ring buffer and process new packages */
665 
666 		while (mp->rx_tail < head) {
667 			mace_dma_rx_frame(dev, (struct mace_frame *) (mp->rx_ring + (mp->rx_tail * 0x0800)));
668 			mp->rx_tail++;
669 		}
670 
671 		/* If we're out of buffers in this ring then switch to */
672 		/* the other set, otherwise just reactivate this one.  */
673 
674 		if (!left) {
675 			mace_load_rxdma_base(dev, mp->rx_slot);
676 			mp->rx_slot ^= 0x10;
677 		} else {
678 			psc_write_word(PSC_ENETRD_CMD + mp->rx_slot, 0x9800);
679 		}
680 	}
681 
682 	/*
683 	 * Process the write queue
684 	 */
685 
686 	status = psc_read_word(PSC_ENETWR_CTL);
687 
688 	if (status & 0x2000) {
689 		mace_txdma_reset(dev);
690 	} else if (status & 0x0100) {
691 		psc_write_word(PSC_ENETWR_CMD + mp->tx_sloti, 0x0100);
692 		mp->tx_sloti ^= 0x10;
693 		mp->tx_count++;
694 		netif_wake_queue(dev);
695 	}
696 }
697 
698 MODULE_LICENSE("GPL");
699