aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/mace.c
blob: 7d7577b598ea294074f65ae0104050fe09a2199c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
/*
 * Network device driver for the MACE ethernet controller on
 * Apple Powermacs.  Assumes it's under a DBDMA controller.
 *
 * Copyright (C) 1996 Paul Mackerras.
 */

#include <linux/module.h>
#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 <linux/init.h>
#include <linux/crc32.h>
#include <linux/spinlock.h>
#include <linux/bitrev.h>
#include <asm/prom.h>
#include <asm/dbdma.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/macio.h>

#include "mace.h"

static int port_aaui = -1;

#define N_RX_RING	8
#define N_TX_RING	6
#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 */

/* Chip rev needs workaround on HW & multicast addr change */
#define BROKEN_ADDRCHG_REV	0x0941

/* Bits in transmit DMA status */
#define TX_DMA_ERR	0x80

struct mace_data {
    volatile struct mace __iomem *mace;
    volatile struct dbdma_regs __iomem *tx_dma;
    int tx_dma_intr;
    volatile struct dbdma_regs __iomem *rx_dma;
    int rx_dma_intr;
    volatile struct dbdma_cmd *tx_cmds;	/* xmit dma command list */
    volatile struct dbdma_cmd *rx_cmds;	/* recv dma command list */
    struct sk_buff *rx_bufs[N_RX_RING];
    int rx_fill;
    int rx_empty;
    struct sk_buff *tx_bufs[N_TX_RING];
    int tx_fill;
    int tx_empty;
    unsigned char maccc;
    unsigned char tx_fullup;
    unsigned char tx_active;
    unsigned char tx_bad_runt;
    struct timer_list tx_timeout;
    int timeout_active;
    int port_aaui;
    int chipid;
    struct macio_dev *mdev;
    spinlock_t lock;
};

/*
 * Number of bytes of private data per MACE: allow enough for
 * the rx and tx dma commands plus a branch dma command each,
 * and another 16 bytes to allow us to align the dma command
 * buffers on a 16 byte boundary.
 */
#define PRIV_BYTES	(sizeof(struct mace_data) \
	+ (N_RX_RING + NCMDS_TX * N_TX_RING + 3) * sizeof(struct dbdma_cmd))

static int mace_open(struct net_device *dev);
static int mace_close(struct net_device *dev);
static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev);
static void mace_set_multicast(struct net_device *dev);
static void mace_reset(struct net_device *dev);
static int mace_set_address(struct net_device *dev, void *addr);
static irqreturn_t mace_interrupt(int irq, void *dev_id);
static irqreturn_t mace_txdma_intr(int irq, void *dev_id);
static irqreturn_t mace_rxdma_intr(int irq, void *dev_id);
static void mace_set_timeout(struct net_device *dev);
static void mace_tx_timeout(unsigned long data);
static inline void dbdma_reset(volatile struct dbdma_regs __iomem *dma);
static inline void mace_clean_rings(struct mace_data *mp);
static void __mace_set_address(struct net_device *dev, void *addr);

/*
 * If we can't get a skbuff when we need it, we use this area for DMA.
 */
static unsigned char *dummy_buf;

static const struct net_device_ops mace_netdev_ops = {
	.ndo_open		= mace_open,
	.ndo_stop		= mace_close,
	.ndo_start_xmit		= mace_xmit_start,
	.ndo_set_multicast_list	= mace_set_multicast,
	.ndo_set_mac_address	= mace_set_address,
	.ndo_change_mtu		= eth_change_mtu,
	.ndo_validate_addr	= eth_validate_addr,
};

static int __devinit mace_probe(struct macio_dev *mdev, const struct of_device_id *match)
{
	struct device_node *mace = macio_get_of_node(mdev);
	struct net_device *dev;
	struct mace_data *mp;
	const unsigned char *addr;
	int j, rev, rc = -EBUSY;

	if (macio_resource_count(mdev) != 3 || macio_irq_count(mdev) != 3) {
		printk(KERN_ERR "can't use MACE %s: need 3 addrs and 3 irqs\n",
		       mace->full_name);
		return -ENODEV;
	}

	addr = of_get_property(mace, "mac-address", NULL);
	if (addr == NULL) {
		addr = of_get_property(mace, "local-mac-address", NULL);
		if (addr == NULL) {
			printk(KERN_ERR "Can't get mac-address for MACE %s\n",
			       mace->full_name);
			return -ENODEV;
		}
	}

	/*
	 * lazy allocate the driver-wide dummy buffer. (Note that we
	 * never have more than one MACE in the system anyway)
	 */
	if (dummy_buf == NULL) {
		dummy_buf = kmalloc(RX_BUFLEN+2, GFP_KERNEL);
		if (dummy_buf == NULL) {
			printk(KERN_ERR "MACE: couldn't allocate dummy buffer\n");
			return -ENOMEM;
		}
	}

	if (macio_request_resources(mdev, "mace")) {
		printk(KERN_ERR "MACE: can't request IO resources !\n");
		return -EBUSY;
	}

	dev = alloc_etherdev(PRIV_BYTES);
	if (!dev) {
		printk(KERN_ERR "MACE: can't allocate ethernet device !\n");
		rc = -ENOMEM;
		goto err_release;
	}
	SET_NETDEV_DEV(dev, &mdev->ofdev.dev);

	mp = netdev_priv(dev);
	mp->mdev = mdev;
	macio_set_drvdata(mdev, dev);

	dev->base_addr = macio_resource_start(mdev, 0);
	mp->mace = ioremap(dev->base_addr, 0x1000);
	if (mp->mace == NULL) {
		printk(KERN_ERR "MACE: can't map IO resources !\n");
		rc = -ENOMEM;
		goto err_free;
	}
	dev->irq = macio_irq(mdev, 0);

	rev = addr[0] == 0 && addr[1] == 0xA0;
	for (j = 0; j < 6; ++j) {
		dev->dev_addr[j] = rev ? bitrev8(addr[j]): addr[j];
	}
	mp->chipid = (in_8(&mp->mace->chipid_hi) << 8) |
			in_8(&mp->mace->chipid_lo);


	mp = netdev_priv(dev);
	mp->maccc = ENXMT | ENRCV;

	mp->tx_dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
	if (mp->tx_dma == NULL) {
		printk(KERN_ERR "MACE: can't map TX DMA resources !\n");
		rc = -ENOMEM;
		goto err_unmap_io;
	}
	mp->tx_dma_intr = macio_irq(mdev, 1);

	mp->rx_dma = ioremap(macio_resource_start(mdev, 2), 0x1000);
	if (mp->rx_dma == NULL) {
		printk(KERN_ERR "MACE: can't map RX DMA resources !\n");
		rc = -ENOMEM;
		goto err_unmap_tx_dma;
	}
	mp->rx_dma_intr = macio_irq(mdev, 2);

	mp->tx_cmds = (volatile struct dbdma_cmd *) DBDMA_ALIGN(mp + 1);
	mp->rx_cmds = mp->tx_cmds + NCMDS_TX * N_TX_RING + 1;

	memset((char *) mp->tx_cmds, 0,
	       (NCMDS_TX*N_TX_RING + N_RX_RING + 2) * sizeof(struct dbdma_cmd));
	init_timer(&mp->tx_timeout);
	spin_lock_init(&mp->lock);
	mp->timeout_active = 0;

	if (port_aaui >= 0)
		mp->port_aaui = port_aaui;
	else {
		/* Apple Network Server uses the AAUI port */
		if (machine_is_compatible("AAPL,ShinerESB"))
			mp->port_aaui = 1;
		else {
#ifdef CONFIG_MACE_AAUI_PORT
			mp->port_aaui = 1;
#else
			mp->port_aaui = 0;
#endif
		}
	}

	dev->netdev_ops = &mace_netdev_ops;

	/*
	 * Most of what is below could be moved to mace_open()
	 */
	mace_reset(dev);

	rc = request_irq(dev->irq, mace_interrupt, 0, "MACE", dev);
	if (rc) {
		printk(KERN_ERR "MACE: can't get irq %d\n", dev->irq);
		goto err_unmap_rx_dma;
	}
	rc = request_irq(mp->tx_dma_intr, mace_txdma_intr, 0, "MACE-txdma", dev);
	if (rc) {
		printk(KERN_ERR "MACE: can't get irq %d\n", mp->tx_dma_intr);
		goto err_free_irq;
	}
	rc = request_irq(mp->rx_dma_intr, mace_rxdma_intr, 0, "MACE-rxdma", dev);
	if (rc) {
		printk(KERN_ERR "MACE: can't get irq %d\n", mp->rx_dma_intr);
		goto err_free_tx_irq;
	}

	rc = register_netdev(dev);
	if (rc) {
		printk(KERN_ERR "MACE: Cannot register net device, aborting.\n");
		goto err_free_rx_irq;
	}

	printk(KERN_INFO "%s: MACE at %pM, chip revision %d.%d\n",
	       dev->name, dev->dev_addr,
	       mp->chipid >> 8, mp->chipid & 0xff);

	return 0;

 err_free_rx_irq:
	free_irq(macio_irq(mdev, 2), dev);
 err_free_tx_irq:
	free_irq(macio_irq(mdev, 1), dev);
 err_free_irq:
	free_irq(macio_irq(mdev, 0), dev);
 err_unmap_rx_dma:
	iounmap(mp->rx_dma);
 err_unmap_tx_dma:
	iounmap(mp->tx_dma);
 err_unmap_io:
	iounmap(mp->mace);
 err_free:
	free_netdev(dev);
 err_release:
	macio_release_resources(mdev);

	return rc;
}

static int __devexit mace_remove(struct macio_dev *mdev)
{
	struct net_device *dev = macio_get_drvdata(mdev);
	struct mace_data *mp;

	BUG_ON(dev == NULL);

	macio_set_drvdata(mdev, NULL);

	mp = netdev_priv(dev);

	unregister_netdev(dev);

	free_irq(dev->irq, dev);
	free_irq(mp->tx_dma_intr, dev);
	free_irq(mp->rx_dma_intr, dev);

	iounmap(mp->rx_dma);
	iounmap(mp->tx_dma);
	iounmap(mp->mace);

	free_netdev(dev);

	macio_release_resources(mdev);

	return 0;
}

static void dbdma_reset(volatile struct dbdma_regs __iomem *dma)
{
    int i;

    out_le32(&dma->control, (WAKE|FLUSH|PAUSE|RUN) << 16);

    /*
     * Yes this looks peculiar, but apparently it needs to be this
     * way on some machines.
     */
    for (i = 200; i > 0; --i)
	if (ld_le32(&dma->control) & RUN)
	    udelay(1);
}

static void mace_reset(struct net_device *dev)
{
    struct mace_data *mp = netdev_priv(dev);
    volatile struct mace __iomem *mb = mp->mace;
    int i;

    /* soft-reset the chip */
    i = 200;
    while (--i) {
	out_8(&mb->biucc, SWRST);
	if (in_8(&mb->biucc) & SWRST) {
	    udelay(10);
	    continue;
	}
	break;
    }
    if (!i) {
	printk(KERN_ERR "mace: cannot reset chip!\n");
	return;
    }

    out_8(&mb->imr, 0xff);	/* disable all intrs for now */
    i = in_8(&mb->ir);
    out_8(&mb->maccc, 0);	/* turn off tx, rx */

    out_8(&mb->biucc, XMTSP_64);
    out_8(&mb->utr, RTRD);
    out_8(&mb->fifocc, RCVFW_32 | XMTFW_16 | XMTFWU | RCVFWU | XMTBRST);
    out_8(&mb->xmtfc, AUTO_PAD_XMIT); /* auto-pad short frames */
    out_8(&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)
	out_8(&mb->iac, LOGADDR);
    else {
	out_8(&mb->iac, ADDRCHG | LOGADDR);
	while ((in_8(&mb->iac) & ADDRCHG) != 0)
		;
    }
    for (i = 0; i < 8; ++i)
	out_8(&mb->ladrf, 0);

    /* done changing address */
    if (mp->chipid != BROKEN_ADDRCHG_REV)
	out_8(&mb->iac, 0);

    if (mp->port_aaui)
    	out_8(&mb->plscc, PORTSEL_AUI + ENPLSIO);
    else
    	out_8(&mb->plscc, PORTSEL_GPSI + ENPLSIO);
}

static void __mace_set_address(struct net_device *dev, void *addr)
{
    struct mace_data *mp = netdev_priv(dev);
    volatile struct mace __iomem *mb = mp->mace;
    unsigned char *p = addr;
    int i;

    /* load up the hardware address */
    if (mp->chipid == BROKEN_ADDRCHG_REV)
    	out_8(&mb->iac, PHYADDR);
    else {
    	out_8(&mb->iac, ADDRCHG | PHYADDR);
	while ((in_8(&mb->iac) & ADDRCHG) != 0)
	    ;
    }
    for (i = 0; i < 6; ++i)
	out_8(&mb->padr, dev->dev_addr[i] = p[i]);
    if (mp->chipid != BROKEN_ADDRCHG_REV)
        out_8(&mb->iac, 0);
}

static int mace_set_address(struct net_device *dev, void *addr)
{
    struct mace_data *mp = netdev_priv(dev);
    volatile struct mace __iomem *mb = mp->mace;
    unsigned long flags;

    spin_lock_irqsave(&mp->lock, flags);

    __mace_set_address(dev, addr);

    /* note: setting ADDRCHG clears ENRCV */
    out_8(&mb->maccc, mp->maccc);

    spin_unlock_irqrestore(&mp->lock, flags);
    return 0;
}

static inline void mace_clean_rings(struct mace_data *mp)
{
    int i;

    /* free some skb's */
    for (i = 0; i < N_RX_RING; ++i) {
	if (mp->rx_bufs[i] != NULL) {
	    dev_kfree_skb(mp->rx_bufs[i]);
	    mp->rx_bufs[i] = NULL;
	}
    }
    for (i = mp->tx_empty; i != mp->tx_fill; ) {
	dev_kfree_skb(mp->tx_bufs[i]);
	if (++i >= N_TX_RING)
	    i = 0;
    }
}

static int mace_open(struct net_device *dev)
{
    struct mace_data *mp = netdev_priv(dev);
    volatile struct mace __iomem *mb = mp->mace;
    volatile struct dbdma_regs __iomem *rd = mp->rx_dma;
    volatile struct dbdma_regs __iomem *td = mp->tx_dma;
    volatile struct dbdma_cmd *cp;
    int i;
    struct sk_buff *skb;
    unsigned char *data;

    /* reset the chip */
    mace_reset(dev);

    /* initialize list of sk_buffs for receiving and set up recv dma */
    mace_clean_rings(mp);
    memset((char *)mp->rx_cmds, 0, N_RX_RING * sizeof(struct dbdma_cmd));
    cp = mp->rx_cmds;
    for (i = 0; i < N_RX_RING - 1; ++i) {
	skb = dev_alloc_skb(RX_BUFLEN + 2);
	if (!skb) {
	    data = dummy_buf;
	} else {
	    skb_reserve(skb, 2);	/* so IP header lands on 4-byte bdry */
	    data = skb->data;
	}
	mp->rx_bufs[i] = skb;
	st_le16(&cp->req_count, RX_BUFLEN);
	st_le16(&cp->command, INPUT_LAST + INTR_ALWAYS);
	st_le32(&cp->phy_addr, virt_to_bus(data));
	cp->xfer_status = 0;
	++cp;
    }
    mp->rx_bufs[i] = NULL;
    st_le16(&cp->command, DBDMA_STOP);
    mp->rx_fill = i;
    mp->rx_empty = 0;

    /* Put a branch back to the beginning of the receive command list */
    ++cp;
    st_le16(&cp->command, DBDMA_NOP + BR_ALWAYS);
    st_le32(&cp->cmd_dep, virt_to_bus(mp->rx_cmds));

    /* start rx dma */
    out_le32(&rd->control, (RUN|PAUSE|FLUSH|WAKE) << 16); /* clear run bit */
    out_le32(&rd->cmdptr, virt_to_bus(mp->rx_cmds));
    out_le32(&rd->control, (RUN << 16) | RUN);

    /* put a branch at the end of the tx command list */
    cp = mp->tx_cmds + NCMDS_TX * N_TX_RING;
    st_le16(&cp->command, DBDMA_NOP + BR_ALWAYS);
    st_le32(&cp->cmd_dep, virt_to_bus(mp->tx_cmds));

    /* reset tx dma */
    out_le32(&td->control, (RUN|PAUSE|FLUSH|WAKE) << 16);
    out_le32(&td->cmdptr, virt_to_bus(mp->tx_cmds));
    mp->tx_fill = 0;
    mp->tx_empty = 0;
    mp->tx_fullup = 0;
    mp->tx_active = 0;
    mp->tx_bad_runt = 0;

    /* turn it on! */
    out_8(&mb->maccc, mp->maccc);
    /* enable all interrupts except receive interrupts */
    out_8(&mb->imr, RCVINT);

    return 0;
}

static int mace_close(struct net_device *dev)
{
    struct mace_data *mp = netdev_priv(dev);
    volatile struct mace __iomem *mb = mp->mace;
    volatile struct dbdma_regs __iomem *rd = mp->rx_dma;
    volatile struct dbdma_regs __iomem *td = mp->tx_dma;

    /* disable rx and tx */
    out_8(&mb->maccc, 0);
    out_8(&mb->imr, 0xff);		/* disable all intrs */

    /* disable rx and tx dma */
    st_le32(&rd->control, (RUN|PAUSE|FLUSH|WAKE) << 16); /* clear run bit */
    st_le32(&td->control, (RUN|PAUSE|FLUSH|WAKE) << 16); /* clear run bit */

    mace_clean_rings(mp);

    return 0;
}

static inline void mace_set_timeout(struct net_device *dev)
{
    struct mace_data *mp = netdev_priv(dev);

    if (mp->timeout_active)
	del_timer(&mp->tx_timeout);
    mp->tx_timeout.expires = jiffies + TX_TIMEOUT;
    mp->tx_timeout.function = mace_tx_timeout;
    mp->tx_timeout.data = (unsigned long) dev;
    add_timer(&mp->tx_timeout);
    mp->timeout_active = 1;
}

static int mace_xmit_start(struct sk_buff *skb, struct net_device *dev)
{
    struct mace_data *mp = netdev_priv(dev);
    volatile struct dbdma_regs __iomem *td = mp->tx_dma;
    volatile struct dbdma_cmd *cp, *np;
    unsigned long flags;
    int fill, next, len;

    /* see if there's a free slot in the tx ring */
    spin_lock_irqsave(&mp->lock, flags);
    fill = mp->tx_fill;
    next = fill + 1;
    if (next >= N_TX_RING)
	next = 0;
    if (next == mp->tx_empty) {
	netif_stop_queue(dev);
	mp->tx_fullup = 1;
	spin_unlock_irqrestore(&mp->lock, flags);
	return NETDEV_TX_BUSY;		/* can't take it at the moment */
    }
    spin_unlock_irqrestore(&mp->lock, flags);

    /* partially fill in the dma command block */
    len = skb->len;
    if (len > ETH_FRAME_LEN) {
	printk(KERN_DEBUG "mace: xmit frame too long (%d)\n", len);
	len = ETH_FRAME_LEN;
    }
    mp->tx_bufs[fill] = skb;
    cp = mp->tx_cmds + NCMDS_TX * fill;
    st_le16(&cp->req_count, len);
    st_le32(&cp->phy_addr, virt_to_bus(skb->data));

    np = mp->tx_cmds + NCMDS_TX * next;
    out_le16(&np->command, DBDMA_STOP);

    /* poke the tx dma channel */
    spin_lock_irqsave(&mp->lock, flags);
    mp->tx_fill = next;
    if (!mp->tx_bad_runt && mp->tx_active < MAX_TX_ACTIVE) {
	out_le16(&cp->xfer_status, 0);
	out_le16(&cp->command, OUTPUT_LAST);
	out_le32(&td->control, ((RUN|WAKE) << 16) + (RUN|WAKE));
	++mp->tx_active;
	mace_set_timeout(dev);
    }
    if (++next >= N_TX_RING)
	next = 0;
    if (next == mp->tx_empty)
	netif_stop_queue(dev);
    spin_unlock_irqrestore(&mp->lock, flags);

    return NETDEV_TX_OK;
}

static void mace_set_multicast(struct net_device *dev)
{
    struct mace_data *mp = netdev_priv(dev);
    volatile struct mace __iomem *mb = mp->mace;
    int i, j;
    u32 crc;
    unsigned long flags;

    spin_lock_irqsave(&mp->lock, flags);
    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 = ether_crc_le(6, dmi->dmi_addr);
		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

	if (mp->chipid == BROKEN_ADDRCHG_REV)
	    out_8(&mb->iac, LOGADDR);
	else {
	    out_8(&mb->iac, ADDRCHG | LOGADDR);
	    while ((in_8(&mb->iac) & ADDRCHG) != 0)
		;
	}
	for (i = 0; i < 8; ++i)
	    out_8(&mb->ladrf, multicast_filter[i]);
	if (mp->chipid != BROKEN_ADDRCHG_REV)
	    out_8(&mb->iac, 0);
    }
    /* reset maccc */
    out_8(&mb->maccc, mp->maccc);
    spin_unlock_irqrestore(&mp->lock, flags);
}

static void mace_handle_misc_intrs(struct mace_data *mp, int intr, struct net_device *dev)
{
    volatile struct mace __iomem *mb = mp->mace;
    static int mace_babbles, mace_jabbers;

    if (intr & MPCO)
	dev->stats.rx_missed_errors += 256;
    dev->stats.rx_missed_errors += in_8(&mb->mpc);   /* reading clears it */
    if (intr & RNTPCO)
	dev->stats.rx_length_errors += 256;
    dev->stats.rx_length_errors += in_8(&mb->rntpc); /* reading clears it */
    if (intr & CERR)
	++dev->stats.tx_heartbeat_errors;
    if (intr & BABBLE)
	if (mace_babbles++ < 4)
	    printk(KERN_DEBUG "mace: babbling transmitter\n");
    if (intr & JABBER)
	if (mace_jabbers++ < 4)
	    printk(KERN_DEBUG "mace: 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 __iomem *mb = mp->mace;
    volatile struct dbdma_regs __iomem *td = mp->tx_dma;
    volatile struct dbdma_cmd *cp;
    int intr, fs, i, stat, x;
    int xcount, dstat;
    unsigned long flags;
    /* static int mace_last_fs, mace_last_xcount; */

    spin_lock_irqsave(&mp->lock, flags);
    intr = in_8(&mb->ir);		/* read interrupt register */
    in_8(&mb->xmtrc);			/* get retries */
    mace_handle_misc_intrs(mp, intr, dev);

    i = mp->tx_empty;
    while (in_8(&mb->pr) & XMTSV) {
	del_timer(&mp->tx_timeout);
	mp->timeout_active = 0;
	/*
	 * Clear any interrupt indication associated with this status
	 * word.  This appears to unlatch any error indication from
	 * the DMA controller.
	 */
	intr = in_8(&mb->ir);
	if (intr != 0)
	    mace_handle_misc_intrs(mp, intr, dev);
	if (mp->tx_bad_runt) {
	    fs = in_8(&mb->xmtfs);
	    mp->tx_bad_runt = 0;
	    out_8(&mb->xmtfc, AUTO_PAD_XMIT);
	    continue;
	}
	dstat = ld_le32(&td->status);
	/* stop DMA controller */
	out_le32(&td->control, RUN << 16);
	/*
	 * xcount is the number of complete frames which have been
	 * written to the fifo but for which status has not been read.
	 */
	xcount = (in_8(&mb->fifofc) >> XMTFC_SH) & XMTFC_MASK;
	if (xcount == 0 || (dstat & DEAD)) {
	    /*
	     * If a packet was aborted before the DMA controller has
	     * finished transferring it, it seems that there are 2 bytes
	     * which are stuck in some buffer somewhere.  These will get
	     * transmitted as soon as we read the frame status (which
	     * reenables the transmit data transfer request).  Turning
	     * off the DMA controller and/or resetting the MACE doesn't
	     * help.  So we disable auto-padding and FCS transmission
	     * so the two bytes will only be a runt packet which should
	     * be ignored by other stations.
	     */
	    out_8(&mb->xmtfc, DXMTFCS);
	}
	fs = in_8(&mb->xmtfs);
	if ((fs & XMTSV) == 0) {
	    printk(KERN_ERR "mace: xmtfs not valid! (fs=%x xc=%d ds=%x)\n",
		   fs, xcount, dstat);
	    mace_reset(dev);
		/*
		 * XXX mace likes to hang the machine after a xmtfs error.
		 * This is hard to reproduce, reseting *may* help
		 */
	}
	cp = mp->tx_cmds + NCMDS_TX * i;
	stat = ld_le16(&cp->xfer_status);
	if ((fs & (UFLO|LCOL|LCAR|RTRY)) || (dstat & DEAD) || xcount == 0) {
	    /*
	     * Check whether there were in fact 2 bytes written to
	     * the transmit FIFO.
	     */
	    udelay(1);
	    x = (in_8(&mb->fifofc) >> XMTFC_SH) & XMTFC_MASK;
	    if (x != 0) {
		/* there were two bytes with an end-of-packet indication */
		mp->tx_bad_runt = 1;
		mace_set_timeout(dev);
	    } else {
		/*
		 * Either there weren't the two bytes buffered up, or they
		 * didn't have an end-of-packet indication.
		 * We flush the transmit FIFO just in case (by setting the
		 * XMTFWU bit with the transmitter disabled).
		 */
		out_8(&mb->maccc, in_8(&mb->maccc) & ~ENXMT);
		out_8(&mb->fifocc, in_8(&mb->fifocc) | XMTFWU);
		udelay(1);
		out_8(&mb->maccc, in_8(&mb->maccc) | ENXMT);
		out_8(&mb->xmtfc, AUTO_PAD_XMIT);
	    }
	}
	/* dma should have finished */
	if (i == mp->tx_fill) {
	    printk(KERN_DEBUG "mace: tx ring ran out? (fs=%x xc=%d ds=%x)\n",
		   fs, xcount, dstat);
	    continue;
	}
	/* Update stats */
	if (fs & (UFLO|LCOL|LCAR|RTRY)) {
	    ++dev->stats.tx_errors;
	    if (fs & LCAR)
		++dev->stats.tx_carrier_errors;
	    if (fs & (UFLO|LCOL|RTRY))
		++dev->stats.tx_aborted_errors;
	} else {
	    dev->stats.tx_bytes += mp->tx_bufs[i]->len;
	    ++dev->stats.tx_packets;
	}
	dev_kfree_skb_irq(mp->tx_bufs[i]);
	--mp->tx_active;
	if (++i >= N_TX_RING)
	    i = 0;
#if 0
	mace_last_fs = fs;
	mace_last_xcount = xcount;
#endif
    }

    if (i != mp->tx_empty) {
	mp->tx_fullup = 0;
	netif_wake_queue(dev);
    }
    mp->tx_empty = i;
    i += mp->tx_active;
    if (i >= N_TX_RING)
	i -= N_TX_RING;
    if (!mp->tx_bad_runt && i != mp->tx_fill && mp->tx_active < MAX_TX_ACTIVE) {
	do {
	    /* set up the next one */
	    cp = mp->tx_cmds + NCMDS_TX * i;
	    out_le16(&cp->xfer_status, 0);
	    out_le16(&cp->command, OUTPUT_LAST);
	    ++mp->tx_active;
	    if (++i >= N_TX_RING)
		i = 0;
	} while (i != mp->tx_fill && mp->tx_active < MAX_TX_ACTIVE);
	out_le32(&td->control, ((RUN|WAKE) << 16) + (RUN|WAKE));
	mace_set_timeout(dev);
    }
    spin_unlock_irqrestore(&mp->lock, flags);
    return IRQ_HANDLED;
}

static void mace_tx_timeout(unsigned long data)
{
    struct net_device *dev = (struct net_device *) data;
    struct mace_data *mp = netdev_priv(dev);
    volatile struct mace __iomem *mb = mp->mace;
    volatile struct dbdma_regs __iomem *td = mp->tx_dma;
    volatile struct dbdma_regs __iomem *rd = mp->rx_dma;
    volatile struct dbdma_cmd *cp;
    unsigned long flags;
    int i;

    spin_lock_irqsave(&mp->lock, flags);
    mp->timeout_active = 0;
    if (mp->tx_active == 0 && !mp->tx_bad_runt)
	goto out;

    /* update various counters */
    mace_handle_misc_intrs(mp, in_8(&mb->ir), dev);

    cp = mp->tx_cmds + NCMDS_TX * mp->tx_empty;

    /* turn off both tx and rx and reset the chip */
    out_8(&mb->maccc, 0);
    printk(KERN_ERR "mace: transmit timeout - resetting\n");
    dbdma_reset(td);
    mace_reset(dev);

    /* restart rx dma */
    cp = bus_to_virt(ld_le32(&rd->cmdptr));
    dbdma_reset(rd);
    out_le16(&cp->xfer_status, 0);
    out_le32(&rd->cmdptr, virt_to_bus(cp));
    out_le32(&rd->control, (RUN << 16) | RUN);

    /* fix up the transmit side */
    i = mp->tx_empty;
    mp->tx_active = 0;
    ++dev->stats.tx_errors;
    if (mp->tx_bad_runt) {
	mp->tx_bad_runt = 0;
    } else if (i != mp->tx_fill) {
	dev_kfree_skb(mp->tx_bufs[i]);
	if (++i >= N_TX_RING)
	    i = 0;
	mp->tx_empty = i;
    }
    mp->tx_fullup = 0;
    netif_wake_queue(dev);
    if (i != mp->tx_fill) {
	cp = mp->tx_cmds + NCMDS_TX * i;
	out_le16(&cp->xfer_status, 0);
	out_le16(&cp->command, OUTPUT_LAST);
	out_le32(&td->cmdptr, virt_to_bus(cp));
	out_le32(&td->control, (RUN << 16) | RUN);
	++mp->tx_active;
	mace_set_timeout(dev);
    }

    /* turn it back on */
    out_8(&mb->imr, RCVINT);
    out_8(&mb->maccc, mp->maccc);

out:
    spin_unlock_irqrestore(&mp->lock, flags);
}

static irqreturn_t mace_txdma_intr(int irq, void *dev_id)
{
	return IRQ_HANDLED;
}

static irqreturn_t mace_rxdma_intr(int irq, void *dev_id)
{
    struct net_device *dev = (struct net_device *) dev_id;
    struct mace_data *mp = netdev_priv(dev);
    volatile struct dbdma_regs __iomem *rd = mp->rx_dma;
    volatile struct dbdma_cmd *cp, *np;
    int i, nb, stat, next;
    struct sk_buff *skb;
    unsigned frame_status;
    static int mace_lost_status;
    unsigned char *data;
    unsigned long flags;

    spin_lock_irqsave(&mp->lock, flags);
    for (i = mp->rx_empty; i != mp->rx_fill; ) {
	cp = mp->rx_cmds + i;
	stat = ld_le16(&cp->xfer_status);
	if ((stat & ACTIVE) == 0) {
	    next = i + 1;
	    if (next >= N_RX_RING)
		next = 0;
	    np = mp->rx_cmds + next;
	    if (next != mp->rx_fill
		&& (ld_le16(&np->xfer_status) & ACTIVE) != 0) {
		printk(KERN_DEBUG "mace: lost a status word\n");
		++mace_lost_status;
	    } else
		break;
	}
	nb = ld_le16(&cp->req_count) - ld_le16(&cp->res_count);
	out_le16(&cp->command, DBDMA_STOP);
	/* got a packet, have a look at it */
	skb = mp->rx_bufs[i];
	if (!skb) {
	    ++dev->stats.rx_dropped;
	} else if (nb > 8) {
	    data = skb->data;
	    frame_status = (data[nb-3] << 8) + data[nb-4];
	    if (frame_status & (RS_OFLO|RS_CLSN|RS_FRAMERR|RS_FCSERR)) {
		++dev->stats.rx_errors;
		if (frame_status & RS_OFLO)
		    ++dev->stats.rx_over_errors;
		if (frame_status & RS_FRAMERR)
		    ++dev->stats.rx_frame_errors;
		if (frame_status & RS_FCSERR)
		    ++dev->stats.rx_crc_errors;
	    } else {
		/* Mace feature AUTO_STRIP_RCV is on by default, dropping the
		 * FCS on frames with 802.3 headers. This means that Ethernet
		 * frames have 8 extra octets at the end, while 802.3 frames
		 * have only 4. We need to correctly account for this. */
		if (*(unsigned short *)(data+12) < 1536) /* 802.3 header */
		    nb -= 4;
		else	/* Ethernet header; mace includes FCS */
		    nb -= 8;
		skb_put(skb, nb);
		skb->protocol = eth_type_trans(skb, dev);
		dev->stats.rx_bytes += skb->len;
		netif_rx(skb);
		mp->rx_bufs[i] = NULL;
		++dev->stats.rx_packets;
	    }
	} else {
	    ++dev->stats.rx_errors;
	    ++dev->stats.rx_length_errors;
	}

	/* advance to next */
	if (++i >= N_RX_RING)
	    i = 0;
    }
    mp->rx_empty = i;

    i = mp->rx_fill;
    for (;;) {
	next = i + 1;
	if (next >= N_RX_RING)
	    next = 0;
	if (next == mp->rx_empty)
	    break;
	cp = mp->rx_cmds + i;
	skb = mp->rx_bufs[i];
	if (!skb) {
	    skb = dev_alloc_skb(RX_BUFLEN + 2);
	    if (skb) {
		skb_reserve(skb, 2);
		mp->rx_bufs[i] = skb;
	    }
	}
	st_le16(&cp->req_count, RX_BUFLEN);
	data = skb? skb->data: dummy_buf;
	st_le32(&cp->phy_addr, virt_to_bus(data));
	out_le16(&cp->xfer_status, 0);
	out_le16(&cp->command, INPUT_LAST + INTR_ALWAYS);
#if 0
	if ((ld_le32(&rd->status) & ACTIVE) != 0) {
	    out_le32(&rd->control, (PAUSE << 16) | PAUSE);
	    while ((in_le32(&rd->status) & ACTIVE) != 0)
		;
	}
#endif
	i = next;
    }
    if (i != mp->rx_fill) {
	out_le32(&rd->control, ((RUN|WAKE) << 16) | (RUN|WAKE));
	mp->rx_fill = i;
    }
    spin_unlock_irqrestore(&mp->lock, flags);
    return IRQ_HANDLED;
}

static struct of_device_id mace_match[] =
{
	{
	.name 		= "mace",
	},
	{},
};
MODULE_DEVICE_TABLE (of, mace_match);

static struct macio_driver mace_driver =
{
	.name 		= "mace",
	.match_table	= mace_match,
	.probe		= mace_probe,
	.remove		= mace_remove,
};


static int __init mace_init(void)
{
	return macio_register_driver(&mace_driver);
}

static void __exit mace_cleanup(void)
{
	macio_unregister_driver(&mace_driver);

	kfree(dummy_buf);
	dummy_buf = NULL;
}

MODULE_AUTHOR("Paul Mackerras");
MODULE_DESCRIPTION("PowerMac MACE driver.");
module_param(port_aaui, int, 0);
MODULE_PARM_DESC(port_aaui, "MACE uses AAUI port (0-1)");
MODULE_LICENSE("GPL");

module_init(mace_init);
module_exit(mace_cleanup);