summaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/sun/sunqe.c
blob: b072f4dba033c1661bf4a341747b1d82d4874fc7 (plain)
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
/* sunqe.c: Sparc QuadEthernet 10baseT SBUS card driver.
 *          Once again I am out to prove that every ethernet
 *          controller out there can be most efficiently programmed
 *          if you make it look like a LANCE.
 *
 * Copyright (C) 1996, 1999, 2003, 2006, 2008 David S. Miller (davem@davemloft.net)
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/crc32.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <asm/io.h>
#include <asm/dma.h>
#include <asm/byteorder.h>
#include <asm/idprom.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/auxio.h>
#include <asm/pgtable.h>
#include <asm/irq.h>

#include "sunqe.h"

#define DRV_NAME	"sunqe"
#define DRV_VERSION	"4.1"
#define DRV_RELDATE	"August 27, 2008"
#define DRV_AUTHOR	"David S. Miller (davem@davemloft.net)"

static char version[] =
	DRV_NAME ".c:v" DRV_VERSION " " DRV_RELDATE " " DRV_AUTHOR "\n";

MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION("Sun QuadEthernet 10baseT SBUS card driver");
MODULE_LICENSE("GPL");

static struct sunqec *root_qec_dev;

static void qe_set_multicast(struct net_device *dev);

#define QEC_RESET_TRIES 200

static inline int qec_global_reset(void __iomem *gregs)
{
	int tries = QEC_RESET_TRIES;

	sbus_writel(GLOB_CTRL_RESET, gregs + GLOB_CTRL);
	while (--tries) {
		u32 tmp = sbus_readl(gregs + GLOB_CTRL);
		if (tmp & GLOB_CTRL_RESET) {
			udelay(20);
			continue;
		}
		break;
	}
	if (tries)
		return 0;
	printk(KERN_ERR "QuadEther: AIEEE cannot reset the QEC!\n");
	return -1;
}

#define MACE_RESET_RETRIES 200
#define QE_RESET_RETRIES   200

static inline int qe_stop(struct sunqe *qep)
{
	void __iomem *cregs = qep->qcregs;
	void __iomem *mregs = qep->mregs;
	int tries;

	/* Reset the MACE, then the QEC channel. */
	sbus_writeb(MREGS_BCONFIG_RESET, mregs + MREGS_BCONFIG);
	tries = MACE_RESET_RETRIES;
	while (--tries) {
		u8 tmp = sbus_readb(mregs + MREGS_BCONFIG);
		if (tmp & MREGS_BCONFIG_RESET) {
			udelay(20);
			continue;
		}
		break;
	}
	if (!tries) {
		printk(KERN_ERR "QuadEther: AIEEE cannot reset the MACE!\n");
		return -1;
	}

	sbus_writel(CREG_CTRL_RESET, cregs + CREG_CTRL);
	tries = QE_RESET_RETRIES;
	while (--tries) {
		u32 tmp = sbus_readl(cregs + CREG_CTRL);
		if (tmp & CREG_CTRL_RESET) {
			udelay(20);
			continue;
		}
		break;
	}
	if (!tries) {
		printk(KERN_ERR "QuadEther: Cannot reset QE channel!\n");
		return -1;
	}
	return 0;
}

static void qe_init_rings(struct sunqe *qep)
{
	struct qe_init_block *qb = qep->qe_block;
	struct sunqe_buffers *qbufs = qep->buffers;
	__u32 qbufs_dvma = qep->buffers_dvma;
	int i;

	qep->rx_new = qep->rx_old = qep->tx_new = qep->tx_old = 0;
	memset(qb, 0, sizeof(struct qe_init_block));
	memset(qbufs, 0, sizeof(struct sunqe_buffers));
	for (i = 0; i < RX_RING_SIZE; i++) {
		qb->qe_rxd[i].rx_addr = qbufs_dvma + qebuf_offset(rx_buf, i);
		qb->qe_rxd[i].rx_flags =
			(RXD_OWN | ((RXD_PKT_SZ) & RXD_LENGTH));
	}
}

static int qe_init(struct sunqe *qep, int from_irq)
{
	struct sunqec *qecp = qep->parent;
	void __iomem *cregs = qep->qcregs;
	void __iomem *mregs = qep->mregs;
	void __iomem *gregs = qecp->gregs;
	unsigned char *e = &qep->dev->dev_addr[0];
	u32 tmp;
	int i;

	/* Shut it up. */
	if (qe_stop(qep))
		return -EAGAIN;

	/* Setup initial rx/tx init block pointers. */
	sbus_writel(qep->qblock_dvma + qib_offset(qe_rxd, 0), cregs + CREG_RXDS);
	sbus_writel(qep->qblock_dvma + qib_offset(qe_txd, 0), cregs + CREG_TXDS);

	/* Enable/mask the various irq's. */
	sbus_writel(0, cregs + CREG_RIMASK);
	sbus_writel(1, cregs + CREG_TIMASK);

	sbus_writel(0, cregs + CREG_QMASK);
	sbus_writel(CREG_MMASK_RXCOLL, cregs + CREG_MMASK);

	/* Setup the FIFO pointers into QEC local memory. */
	tmp = qep->channel * sbus_readl(gregs + GLOB_MSIZE);
	sbus_writel(tmp, cregs + CREG_RXRBUFPTR);
	sbus_writel(tmp, cregs + CREG_RXWBUFPTR);

	tmp = sbus_readl(cregs + CREG_RXRBUFPTR) +
		sbus_readl(gregs + GLOB_RSIZE);
	sbus_writel(tmp, cregs + CREG_TXRBUFPTR);
	sbus_writel(tmp, cregs + CREG_TXWBUFPTR);

	/* Clear the channel collision counter. */
	sbus_writel(0, cregs + CREG_CCNT);

	/* For 10baseT, inter frame space nor throttle seems to be necessary. */
	sbus_writel(0, cregs + CREG_PIPG);

	/* Now dork with the AMD MACE. */
	sbus_writeb(MREGS_PHYCONFIG_AUTO, mregs + MREGS_PHYCONFIG);
	sbus_writeb(MREGS_TXFCNTL_AUTOPAD, mregs + MREGS_TXFCNTL);
	sbus_writeb(0, mregs + MREGS_RXFCNTL);

	/* The QEC dma's the rx'd packets from local memory out to main memory,
	 * and therefore it interrupts when the packet reception is "complete".
	 * So don't listen for the MACE talking about it.
	 */
	sbus_writeb(MREGS_IMASK_COLL | MREGS_IMASK_RXIRQ, mregs + MREGS_IMASK);
	sbus_writeb(MREGS_BCONFIG_BSWAP | MREGS_BCONFIG_64TS, mregs + MREGS_BCONFIG);
	sbus_writeb((MREGS_FCONFIG_TXF16 | MREGS_FCONFIG_RXF32 |
		     MREGS_FCONFIG_RFWU | MREGS_FCONFIG_TFWU),
		    mregs + MREGS_FCONFIG);

	/* Only usable interface on QuadEther is twisted pair. */
	sbus_writeb(MREGS_PLSCONFIG_TP, mregs + MREGS_PLSCONFIG);

	/* Tell MACE we are changing the ether address. */
	sbus_writeb(MREGS_IACONFIG_ACHNGE | MREGS_IACONFIG_PARESET,
		    mregs + MREGS_IACONFIG);
	while ((sbus_readb(mregs + MREGS_IACONFIG) & MREGS_IACONFIG_ACHNGE) != 0)
		barrier();
	sbus_writeb(e[0], mregs + MREGS_ETHADDR);
	sbus_writeb(e[1], mregs + MREGS_ETHADDR);
	sbus_writeb(e[2], mregs + MREGS_ETHADDR);
	sbus_writeb(e[3], mregs + MREGS_ETHADDR);
	sbus_writeb(e[4], mregs + MREGS_ETHADDR);
	sbus_writeb(e[5], mregs + MREGS_ETHADDR);

	/* Clear out the address filter. */
	sbus_writeb(MREGS_IACONFIG_ACHNGE | MREGS_IACONFIG_LARESET,
		    mregs + MREGS_IACONFIG);
	while ((sbus_readb(mregs + MREGS_IACONFIG) & MREGS_IACONFIG_ACHNGE) != 0)
		barrier();
	for (i = 0; i < 8; i++)
		sbus_writeb(0, mregs + MREGS_FILTER);

	/* Address changes are now complete. */
	sbus_writeb(0, mregs + MREGS_IACONFIG);

	qe_init_rings(qep);

	/* Wait a little bit for the link to come up... */
	mdelay(5);
	if (!(sbus_readb(mregs + MREGS_PHYCONFIG) & MREGS_PHYCONFIG_LTESTDIS)) {
		int tries = 50;

		while (--tries) {
			u8 tmp;

			mdelay(5);
			barrier();
			tmp = sbus_readb(mregs + MREGS_PHYCONFIG);
			if ((tmp & MREGS_PHYCONFIG_LSTAT) != 0)
				break;
		}
		if (tries == 0)
			printk(KERN_NOTICE "%s: Warning, link state is down.\n", qep->dev->name);
	}

	/* Missed packet counter is cleared on a read. */
	sbus_readb(mregs + MREGS_MPCNT);

	/* Reload multicast information, this will enable the receiver
	 * and transmitter.
	 */
	qe_set_multicast(qep->dev);

	/* QEC should now start to show interrupts. */
	return 0;
}

/* Grrr, certain error conditions completely lock up the AMD MACE,
 * so when we get these we _must_ reset the chip.
 */
static int qe_is_bolixed(struct sunqe *qep, u32 qe_status)
{
	struct net_device *dev = qep->dev;
	int mace_hwbug_workaround = 0;

	if (qe_status & CREG_STAT_EDEFER) {
		printk(KERN_ERR "%s: Excessive transmit defers.\n", dev->name);
		dev->stats.tx_errors++;
	}

	if (qe_status & CREG_STAT_CLOSS) {
		printk(KERN_ERR "%s: Carrier lost, link down?\n", dev->name);
		dev->stats.tx_errors++;
		dev->stats.tx_carrier_errors++;
	}

	if (qe_status & CREG_STAT_ERETRIES) {
		printk(KERN_ERR "%s: Excessive transmit retries (more than 16).\n", dev->name);
		dev->stats.tx_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_LCOLL) {
		printk(KERN_ERR "%s: Late transmit collision.\n", dev->name);
		dev->stats.tx_errors++;
		dev->stats.collisions++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_FUFLOW) {
		printk(KERN_ERR "%s: Transmit fifo underflow, driver bug.\n", dev->name);
		dev->stats.tx_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_JERROR) {
		printk(KERN_ERR "%s: Jabber error.\n", dev->name);
	}

	if (qe_status & CREG_STAT_BERROR) {
		printk(KERN_ERR "%s: Babble error.\n", dev->name);
	}

	if (qe_status & CREG_STAT_CCOFLOW) {
		dev->stats.tx_errors += 256;
		dev->stats.collisions += 256;
	}

	if (qe_status & CREG_STAT_TXDERROR) {
		printk(KERN_ERR "%s: Transmit descriptor is bogus, driver bug.\n", dev->name);
		dev->stats.tx_errors++;
		dev->stats.tx_aborted_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_TXLERR) {
		printk(KERN_ERR "%s: Transmit late error.\n", dev->name);
		dev->stats.tx_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_TXPERR) {
		printk(KERN_ERR "%s: Transmit DMA parity error.\n", dev->name);
		dev->stats.tx_errors++;
		dev->stats.tx_aborted_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_TXSERR) {
		printk(KERN_ERR "%s: Transmit DMA sbus error ack.\n", dev->name);
		dev->stats.tx_errors++;
		dev->stats.tx_aborted_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_RCCOFLOW) {
		dev->stats.rx_errors += 256;
		dev->stats.collisions += 256;
	}

	if (qe_status & CREG_STAT_RUOFLOW) {
		dev->stats.rx_errors += 256;
		dev->stats.rx_over_errors += 256;
	}

	if (qe_status & CREG_STAT_MCOFLOW) {
		dev->stats.rx_errors += 256;
		dev->stats.rx_missed_errors += 256;
	}

	if (qe_status & CREG_STAT_RXFOFLOW) {
		printk(KERN_ERR "%s: Receive fifo overflow.\n", dev->name);
		dev->stats.rx_errors++;
		dev->stats.rx_over_errors++;
	}

	if (qe_status & CREG_STAT_RLCOLL) {
		printk(KERN_ERR "%s: Late receive collision.\n", dev->name);
		dev->stats.rx_errors++;
		dev->stats.collisions++;
	}

	if (qe_status & CREG_STAT_FCOFLOW) {
		dev->stats.rx_errors += 256;
		dev->stats.rx_frame_errors += 256;
	}

	if (qe_status & CREG_STAT_CECOFLOW) {
		dev->stats.rx_errors += 256;
		dev->stats.rx_crc_errors += 256;
	}

	if (qe_status & CREG_STAT_RXDROP) {
		printk(KERN_ERR "%s: Receive packet dropped.\n", dev->name);
		dev->stats.rx_errors++;
		dev->stats.rx_dropped++;
		dev->stats.rx_missed_errors++;
	}

	if (qe_status & CREG_STAT_RXSMALL) {
		printk(KERN_ERR "%s: Receive buffer too small, driver bug.\n", dev->name);
		dev->stats.rx_errors++;
		dev->stats.rx_length_errors++;
	}

	if (qe_status & CREG_STAT_RXLERR) {
		printk(KERN_ERR "%s: Receive late error.\n", dev->name);
		dev->stats.rx_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_RXPERR) {
		printk(KERN_ERR "%s: Receive DMA parity error.\n", dev->name);
		dev->stats.rx_errors++;
		dev->stats.rx_missed_errors++;
		mace_hwbug_workaround = 1;
	}

	if (qe_status & CREG_STAT_RXSERR) {
		printk(KERN_ERR "%s: Receive DMA sbus error ack.\n", dev->name);
		dev->stats.rx_errors++;
		dev->stats.rx_missed_errors++;
		mace_hwbug_workaround = 1;
	}

	if (mace_hwbug_workaround)
		qe_init(qep, 1);
	return mace_hwbug_workaround;
}

/* Per-QE receive interrupt service routine.  Just like on the happy meal
 * we receive directly into skb's with a small packet copy water mark.
 */
static void qe_rx(struct sunqe *qep)
{
	struct qe_rxd *rxbase = &qep->qe_block->qe_rxd[0];
	struct net_device *dev = qep->dev;
	struct qe_rxd *this;
	struct sunqe_buffers *qbufs = qep->buffers;
	__u32 qbufs_dvma = qep->buffers_dvma;
	int elem = qep->rx_new;
	u32 flags;

	this = &rxbase[elem];
	while (!((flags = this->rx_flags) & RXD_OWN)) {
		struct sk_buff *skb;
		unsigned char *this_qbuf =
			&qbufs->rx_buf[elem & (RX_RING_SIZE - 1)][0];
		__u32 this_qbuf_dvma = qbufs_dvma +
			qebuf_offset(rx_buf, (elem & (RX_RING_SIZE - 1)));
		struct qe_rxd *end_rxd =
			&rxbase[(elem+RX_RING_SIZE)&(RX_RING_MAXSIZE-1)];
		int len = (flags & RXD_LENGTH) - 4;  /* QE adds ether FCS size to len */

		/* Check for errors. */
		if (len < ETH_ZLEN) {
			dev->stats.rx_errors++;
			dev->stats.rx_length_errors++;
			dev->stats.rx_dropped++;
		} else {
			skb = netdev_alloc_skb(dev, len + 2);
			if (skb == NULL) {
				dev->stats.rx_dropped++;
			} else {
				skb_reserve(skb, 2);
				skb_put(skb, len);
				skb_copy_to_linear_data(skb, this_qbuf,
						 len);
				skb->protocol = eth_type_trans(skb, qep->dev);
				netif_rx(skb);
				dev->stats.rx_packets++;
				dev->stats.rx_bytes += len;
			}
		}
		end_rxd->rx_addr = this_qbuf_dvma;
		end_rxd->rx_flags = (RXD_OWN | ((RXD_PKT_SZ) & RXD_LENGTH));

		elem = NEXT_RX(elem);
		this = &rxbase[elem];
	}
	qep->rx_new = elem;
}

static void qe_tx_reclaim(struct sunqe *qep);

/* Interrupts for all QE's get filtered out via the QEC master controller,
 * so we just run through each qe and check to see who is signaling
 * and thus needs to be serviced.
 */
static irqreturn_t qec_interrupt(int irq, void *dev_id)
{
	struct sunqec *qecp = dev_id;
	u32 qec_status;
	int channel = 0;

	/* Latch the status now. */
	qec_status = sbus_readl(qecp->gregs + GLOB_STAT);
	while (channel < 4) {
		if (qec_status & 0xf) {
			struct sunqe *qep = qecp->qes[channel];
			u32 qe_status;

			qe_status = sbus_readl(qep->qcregs + CREG_STAT);
			if (qe_status & CREG_STAT_ERRORS) {
				if (qe_is_bolixed(qep, qe_status))
					goto next;
			}
			if (qe_status & CREG_STAT_RXIRQ)
				qe_rx(qep);
			if (netif_queue_stopped(qep->dev) &&
			    (qe_status & CREG_STAT_TXIRQ)) {
				spin_lock(&qep->lock);
				qe_tx_reclaim(qep);
				if (TX_BUFFS_AVAIL(qep) > 0) {
					/* Wake net queue and return to
					 * lazy tx reclaim.
					 */
					netif_wake_queue(qep->dev);
					sbus_writel(1, qep->qcregs + CREG_TIMASK);
				}
				spin_unlock(&qep->lock);
			}
	next:
			;
		}
		qec_status >>= 4;
		channel++;
	}

	return IRQ_HANDLED;
}

static int qe_open(struct net_device *dev)
{
	struct sunqe *qep = netdev_priv(dev);

	qep->mconfig = (MREGS_MCONFIG_TXENAB |
			MREGS_MCONFIG_RXENAB |
			MREGS_MCONFIG_MBAENAB);
	return qe_init(qep, 0);
}

static int qe_close(struct net_device *dev)
{
	struct sunqe *qep = netdev_priv(dev);

	qe_stop(qep);
	return 0;
}

/* Reclaim TX'd frames from the ring.  This must always run under
 * the IRQ protected qep->lock.
 */
static void qe_tx_reclaim(struct sunqe *qep)
{
	struct qe_txd *txbase = &qep->qe_block->qe_txd[0];
	int elem = qep->tx_old;

	while (elem != qep->tx_new) {
		u32 flags = txbase[elem].tx_flags;

		if (flags & TXD_OWN)
			break;
		elem = NEXT_TX(elem);
	}
	qep->tx_old = elem;
}

static void qe_tx_timeout(struct net_device *dev)
{
	struct sunqe *qep = netdev_priv(dev);
	int tx_full;

	spin_lock_irq(&qep->lock);

	/* Try to reclaim, if that frees up some tx
	 * entries, we're fine.
	 */
	qe_tx_reclaim(qep);
	tx_full = TX_BUFFS_AVAIL(qep) <= 0;

	spin_unlock_irq(&qep->lock);

	if (! tx_full)
		goto out;

	printk(KERN_ERR "%s: transmit timed out, resetting\n", dev->name);
	qe_init(qep, 1);

out:
	netif_wake_queue(dev);
}

/* Get a packet queued to go onto the wire. */
static int qe_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct sunqe *qep = netdev_priv(dev);
	struct sunqe_buffers *qbufs = qep->buffers;
	__u32 txbuf_dvma, qbufs_dvma = qep->buffers_dvma;
	unsigned char *txbuf;
	int len, entry;

	spin_lock_irq(&qep->lock);

	qe_tx_reclaim(qep);

	len = skb->len;
	entry = qep->tx_new;

	txbuf = &qbufs->tx_buf[entry & (TX_RING_SIZE - 1)][0];
	txbuf_dvma = qbufs_dvma +
		qebuf_offset(tx_buf, (entry & (TX_RING_SIZE - 1)));

	/* Avoid a race... */
	qep->qe_block->qe_txd[entry].tx_flags = TXD_UPDATE;

	skb_copy_from_linear_data(skb, txbuf, len);

	qep->qe_block->qe_txd[entry].tx_addr = txbuf_dvma;
	qep->qe_block->qe_txd[entry].tx_flags =
		(TXD_OWN | TXD_SOP | TXD_EOP | (len & TXD_LENGTH));
	qep->tx_new = NEXT_TX(entry);

	/* Get it going. */
	sbus_writel(CREG_CTRL_TWAKEUP, qep->qcregs + CREG_CTRL);

	dev->stats.tx_packets++;
	dev->stats.tx_bytes += len;

	if (TX_BUFFS_AVAIL(qep) <= 0) {
		/* Halt the net queue and enable tx interrupts.
		 * When the tx queue empties the tx irq handler
		 * will wake up the queue and return us back to
		 * the lazy tx reclaim scheme.
		 */
		netif_stop_queue(dev);
		sbus_writel(0, qep->qcregs + CREG_TIMASK);
	}
	spin_unlock_irq(&qep->lock);

	dev_kfree_skb(skb);

	return NETDEV_TX_OK;
}

static void qe_set_multicast(struct net_device *dev)
{
	struct sunqe *qep = netdev_priv(dev);
	struct netdev_hw_addr *ha;
	u8 new_mconfig = qep->mconfig;
	int i;
	u32 crc;

	/* Lock out others. */
	netif_stop_queue(dev);

	if ((dev->flags & IFF_ALLMULTI) || (netdev_mc_count(dev) > 64)) {
		sbus_writeb(MREGS_IACONFIG_ACHNGE | MREGS_IACONFIG_LARESET,
			    qep->mregs + MREGS_IACONFIG);
		while ((sbus_readb(qep->mregs + MREGS_IACONFIG) & MREGS_IACONFIG_ACHNGE) != 0)
			barrier();
		for (i = 0; i < 8; i++)
			sbus_writeb(0xff, qep->mregs + MREGS_FILTER);
		sbus_writeb(0, qep->mregs + MREGS_IACONFIG);
	} else if (dev->flags & IFF_PROMISC) {
		new_mconfig |= MREGS_MCONFIG_PROMISC;
	} else {
		u16 hash_table[4];
		u8 *hbytes = (unsigned char *) &hash_table[0];

		memset(hash_table, 0, sizeof(hash_table));
		netdev_for_each_mc_addr(ha, dev) {
			crc = ether_crc_le(6, ha->addr);
			crc >>= 26;
			hash_table[crc >> 4] |= 1 << (crc & 0xf);
		}
		/* Program the qe with the new filter value. */
		sbus_writeb(MREGS_IACONFIG_ACHNGE | MREGS_IACONFIG_LARESET,
			    qep->mregs + MREGS_IACONFIG);
		while ((sbus_readb(qep->mregs + MREGS_IACONFIG) & MREGS_IACONFIG_ACHNGE) != 0)
			barrier();
		for (i = 0; i < 8; i++) {
			u8 tmp = *hbytes++;
			sbus_writeb(tmp, qep->mregs + MREGS_FILTER);
		}
		sbus_writeb(0, qep->mregs + MREGS_IACONFIG);
	}

	/* Any change of the logical address filter, the physical address,
	 * or enabling/disabling promiscuous mode causes the MACE to disable
	 * the receiver.  So we must re-enable them here or else the MACE
	 * refuses to listen to anything on the network.  Sheesh, took
	 * me a day or two to find this bug.
	 */
	qep->mconfig = new_mconfig;
	sbus_writeb(qep->mconfig, qep->mregs + MREGS_MCONFIG);

	/* Let us get going again. */
	netif_wake_queue(dev);
}

/* Ethtool support... */
static void qe_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
	const struct linux_prom_registers *regs;
	struct sunqe *qep = netdev_priv(dev);
	struct platform_device *op;

	strlcpy(info->driver, "sunqe", sizeof(info->driver));
	strlcpy(info->version, "3.0", sizeof(info->version));

	op = qep->op;
	regs = of_get_property(op->dev.of_node, "reg", NULL);
	if (regs)
		snprintf(info->bus_info, sizeof(info->bus_info), "SBUS:%d",
			 regs->which_io);

}

static u32 qe_get_link(struct net_device *dev)
{
	struct sunqe *qep = netdev_priv(dev);
	void __iomem *mregs = qep->mregs;
	u8 phyconfig;

	spin_lock_irq(&qep->lock);
	phyconfig = sbus_readb(mregs + MREGS_PHYCONFIG);
	spin_unlock_irq(&qep->lock);

	return phyconfig & MREGS_PHYCONFIG_LSTAT;
}

static const struct ethtool_ops qe_ethtool_ops = {
	.get_drvinfo		= qe_get_drvinfo,
	.get_link		= qe_get_link,
};

/* This is only called once at boot time for each card probed. */
static void qec_init_once(struct sunqec *qecp, struct platform_device *op)
{
	u8 bsizes = qecp->qec_bursts;

	if (sbus_can_burst64() && (bsizes & DMA_BURST64)) {
		sbus_writel(GLOB_CTRL_B64, qecp->gregs + GLOB_CTRL);
	} else if (bsizes & DMA_BURST32) {
		sbus_writel(GLOB_CTRL_B32, qecp->gregs + GLOB_CTRL);
	} else {
		sbus_writel(GLOB_CTRL_B16, qecp->gregs + GLOB_CTRL);
	}

	/* Packetsize only used in 100baseT BigMAC configurations,
	 * set it to zero just to be on the safe side.
	 */
	sbus_writel(GLOB_PSIZE_2048, qecp->gregs + GLOB_PSIZE);

	/* Set the local memsize register, divided up to one piece per QE channel. */
	sbus_writel((resource_size(&op->resource[1]) >> 2),
		    qecp->gregs + GLOB_MSIZE);

	/* Divide up the local QEC memory amongst the 4 QE receiver and
	 * transmitter FIFOs.  Basically it is (total / 2 / num_channels).
	 */
	sbus_writel((resource_size(&op->resource[1]) >> 2) >> 1,
		    qecp->gregs + GLOB_TSIZE);
	sbus_writel((resource_size(&op->resource[1]) >> 2) >> 1,
		    qecp->gregs + GLOB_RSIZE);
}

static u8 qec_get_burst(struct device_node *dp)
{
	u8 bsizes, bsizes_more;

	/* Find and set the burst sizes for the QEC, since it
	 * does the actual dma for all 4 channels.
	 */
	bsizes = of_getintprop_default(dp, "burst-sizes", 0xff);
	bsizes &= 0xff;
	bsizes_more = of_getintprop_default(dp->parent, "burst-sizes", 0xff);

	if (bsizes_more != 0xff)
		bsizes &= bsizes_more;
	if (bsizes == 0xff || (bsizes & DMA_BURST16) == 0 ||
	    (bsizes & DMA_BURST32)==0)
		bsizes = (DMA_BURST32 - 1);

	return bsizes;
}

static struct sunqec *get_qec(struct platform_device *child)
{
	struct platform_device *op = to_platform_device(child->dev.parent);
	struct sunqec *qecp;

	qecp = platform_get_drvdata(op);
	if (!qecp) {
		qecp = kzalloc(sizeof(struct sunqec), GFP_KERNEL);
		if (qecp) {
			u32 ctrl;

			qecp->op = op;
			qecp->gregs = of_ioremap(&op->resource[0], 0,
						 GLOB_REG_SIZE,
						 "QEC Global Registers");
			if (!qecp->gregs)
				goto fail;

			/* Make sure the QEC is in MACE mode. */
			ctrl = sbus_readl(qecp->gregs + GLOB_CTRL);
			ctrl &= 0xf0000000;
			if (ctrl != GLOB_CTRL_MMODE) {
				printk(KERN_ERR "qec: Not in MACE mode!\n");
				goto fail;
			}

			if (qec_global_reset(qecp->gregs))
				goto fail;

			qecp->qec_bursts = qec_get_burst(op->dev.of_node);

			qec_init_once(qecp, op);

			if (request_irq(op->archdata.irqs[0], qec_interrupt,
					IRQF_SHARED, "qec", (void *) qecp)) {
				printk(KERN_ERR "qec: Can't register irq.\n");
				goto fail;
			}

			platform_set_drvdata(op, qecp);

			qecp->next_module = root_qec_dev;
			root_qec_dev = qecp;
		}
	}

	return qecp;

fail:
	if (qecp->gregs)
		of_iounmap(&op->resource[0], qecp->gregs, GLOB_REG_SIZE);
	kfree(qecp);
	return NULL;
}

static const struct net_device_ops qec_ops = {
	.ndo_open		= qe_open,
	.ndo_stop		= qe_close,
	.ndo_start_xmit		= qe_start_xmit,
	.ndo_set_rx_mode	= qe_set_multicast,
	.ndo_tx_timeout		= qe_tx_timeout,
	.ndo_change_mtu		= eth_change_mtu,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
};

static int qec_ether_init(struct platform_device *op)
{
	static unsigned version_printed;
	struct net_device *dev;
	struct sunqec *qecp;
	struct sunqe *qe;
	int i, res;

	if (version_printed++ == 0)
		printk(KERN_INFO "%s", version);

	dev = alloc_etherdev(sizeof(struct sunqe));
	if (!dev)
		return -ENOMEM;

	memcpy(dev->dev_addr, idprom->id_ethaddr, 6);

	qe = netdev_priv(dev);

	res = -ENODEV;

	i = of_getintprop_default(op->dev.of_node, "channel#", -1);
	if (i == -1)
		goto fail;
	qe->channel = i;
	spin_lock_init(&qe->lock);

	qecp = get_qec(op);
	if (!qecp)
		goto fail;

	qecp->qes[qe->channel] = qe;
	qe->dev = dev;
	qe->parent = qecp;
	qe->op = op;

	res = -ENOMEM;
	qe->qcregs = of_ioremap(&op->resource[0], 0,
				CREG_REG_SIZE, "QEC Channel Registers");
	if (!qe->qcregs) {
		printk(KERN_ERR "qe: Cannot map channel registers.\n");
		goto fail;
	}

	qe->mregs = of_ioremap(&op->resource[1], 0,
			       MREGS_REG_SIZE, "QE MACE Registers");
	if (!qe->mregs) {
		printk(KERN_ERR "qe: Cannot map MACE registers.\n");
		goto fail;
	}

	qe->qe_block = dma_alloc_coherent(&op->dev, PAGE_SIZE,
					  &qe->qblock_dvma, GFP_ATOMIC);
	qe->buffers = dma_alloc_coherent(&op->dev, sizeof(struct sunqe_buffers),
					 &qe->buffers_dvma, GFP_ATOMIC);
	if (qe->qe_block == NULL || qe->qblock_dvma == 0 ||
	    qe->buffers == NULL || qe->buffers_dvma == 0)
		goto fail;

	/* Stop this QE. */
	qe_stop(qe);

	SET_NETDEV_DEV(dev, &op->dev);

	dev->watchdog_timeo = 5*HZ;
	dev->irq = op->archdata.irqs[0];
	dev->dma = 0;
	dev->ethtool_ops = &qe_ethtool_ops;
	dev->netdev_ops = &qec_ops;

	res = register_netdev(dev);
	if (res)
		goto fail;

	platform_set_drvdata(op, qe);

	printk(KERN_INFO "%s: qe channel[%d] %pM\n", dev->name, qe->channel,
	       dev->dev_addr);
	return 0;

fail:
	if (qe->qcregs)
		of_iounmap(&op->resource[0], qe->qcregs, CREG_REG_SIZE);
	if (qe->mregs)
		of_iounmap(&op->resource[1], qe->mregs, MREGS_REG_SIZE);
	if (qe->qe_block)
		dma_free_coherent(&op->dev, PAGE_SIZE,
				  qe->qe_block, qe->qblock_dvma);
	if (qe->buffers)
		dma_free_coherent(&op->dev,
				  sizeof(struct sunqe_buffers),
				  qe->buffers,
				  qe->buffers_dvma);

	free_netdev(dev);

	return res;
}

static int qec_sbus_probe(struct platform_device *op)
{
	return qec_ether_init(op);
}

static int qec_sbus_remove(struct platform_device *op)
{
	struct sunqe *qp = platform_get_drvdata(op);
	struct net_device *net_dev = qp->dev;

	unregister_netdev(net_dev);

	of_iounmap(&op->resource[0], qp->qcregs, CREG_REG_SIZE);
	of_iounmap(&op->resource[1], qp->mregs, MREGS_REG_SIZE);
	dma_free_coherent(&op->dev, PAGE_SIZE,
			  qp->qe_block, qp->qblock_dvma);
	dma_free_coherent(&op->dev, sizeof(struct sunqe_buffers),
			  qp->buffers, qp->buffers_dvma);

	free_netdev(net_dev);

	return 0;
}

static const struct of_device_id qec_sbus_match[] = {
	{
		.name = "qe",
	},
	{},
};

MODULE_DEVICE_TABLE(of, qec_sbus_match);

static struct platform_driver qec_sbus_driver = {
	.driver = {
		.name = "qec",
		.owner = THIS_MODULE,
		.of_match_table = qec_sbus_match,
	},
	.probe		= qec_sbus_probe,
	.remove		= qec_sbus_remove,
};

static int __init qec_init(void)
{
	return platform_driver_register(&qec_sbus_driver);
}

static void __exit qec_exit(void)
{
	platform_driver_unregister(&qec_sbus_driver);

	while (root_qec_dev) {
		struct sunqec *next = root_qec_dev->next_module;
		struct platform_device *op = root_qec_dev->op;

		free_irq(op->archdata.irqs[0], (void *) root_qec_dev);
		of_iounmap(&op->resource[0], root_qec_dev->gregs,
			   GLOB_REG_SIZE);
		kfree(root_qec_dev);

		root_qec_dev = next;
	}
}

module_init(qec_init);
module_exit(qec_exit);