aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/ibmlana.c
blob: 6969bf17588f47895e5b3fb84f276a14fa589d29 (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
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
/*
net-3-driver for the IBM LAN Adapter/A

This is an extension to the Linux operating system, and is covered by the
same GNU General Public License that covers that work.

Copyright 1999 by Alfred Arnold (alfred@ccac.rwth-aachen.de,
                                 alfred.arnold@lancom.de)

This driver is based both on the SK_MCA driver, which is itself based on the
SK_G16 and 3C523 driver.

paper sources:
  'PC Hardware: Aufbau, Funktionsweise, Programmierung' by
  Hans-Peter Messmer for the basic Microchannel stuff

  'Linux Geraetetreiber' by Allesandro Rubini, Kalle Dalheimer
  for help on Ethernet driver programming

  'DP83934CVUL-20/25 MHz SONIC-T Ethernet Controller Datasheet' by National
  Semiconductor for info on the MAC chip

  'LAN Technical Reference Ethernet Adapter Interface Version 1 Release 1.0
   Document Number SC30-3661-00' by IBM for info on the adapter itself

  Also see http://www.natsemi.com/

special acknowledgements to:
  - Bob Eager for helping me out with documentation from IBM
  - Jim Shorney for his endless patience with me while I was using
    him as a beta tester to trace down the address filter bug ;-)

  Missing things:

  -> set debug level via ioctl instead of compile-time switches
  -> I didn't follow the development of the 2.1.x kernels, so my
     assumptions about which things changed with which kernel version
     are probably nonsense

History:
  Nov 6th, 1999
  	startup from SK_MCA driver
  Dec 6th, 1999
	finally got docs about the card.  A big thank you to Bob Eager!
  Dec 12th, 1999
	first packet received
  Dec 13th, 1999
	recv queue done, tcpdump works
  Dec 15th, 1999
	transmission part works
  Dec 28th, 1999
	added usage of the isa_functions for Linux 2.3 .  Things should
	still work with 2.0.x....
  Jan 28th, 2000
	in Linux 2.2.13, the version.h file mysteriously didn't get
	included.  Added a workaround for this.  Futhermore, it now
	not only compiles as a modules ;-)
  Jan 30th, 2000
	newer kernels automatically probe more than one board, so the
	'startslot' as a variable is also needed here
  Apr 12th, 2000
	the interrupt mask register is not set 'hard' instead of individually
	setting registers, since this seems to set bits that shouldn't be
	set
  May 21st, 2000
	reset interrupt status immediately after CAM load
	add a recovery delay after releasing the chip's reset line
  May 24th, 2000
	finally found the bug in the address filter setup - damned signed
        chars!
  June 1st, 2000
	corrected version codes, added support for the latest 2.3 changes
  Oct 28th, 2002
  	cleaned up for the 2.5 tree <alan@redhat.com>

 *************************************************************************/

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/time.h>
#include <linux/mca-legacy.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/bitops.h>

#include <asm/processor.h>
#include <asm/io.h>

#define _IBM_LANA_DRIVER_
#include "ibmlana.h"

#undef DEBUG

#define DRV_NAME "ibmlana"

/* ------------------------------------------------------------------------
 * global static data - not more since we can handle multiple boards and
 * have to pack all state info into the device struct!
 * ------------------------------------------------------------------------ */

static char *MediaNames[Media_Count] = {
	"10BaseT", "10Base5", "Unknown", "10Base2"
};

/* ------------------------------------------------------------------------
 * private subfunctions
 * ------------------------------------------------------------------------ */

#ifdef DEBUG
  /* dump all registers */

static void dumpregs(struct net_device *dev)
{
	int z;

	for (z = 0; z < 160; z += 2) {
		if (!(z & 15))
			printk("REGS: %04x:", z);
		printk(" %04x", inw(dev->base_addr + z));
		if ((z & 15) == 14)
			printk("\n");
	}
}

/* dump parts of shared memory - only needed during debugging */

static void dumpmem(struct net_device *dev, u32 start, u32 len)
{
	ibmlana_priv *priv = netdev_priv(dev);
	int z;

	printk("Address %04x:\n", start);
	for (z = 0; z < len; z++) {
		if ((z & 15) == 0)
			printk("%04x:", z);
		printk(" %02x", readb(priv->base + start + z));
		if ((z & 15) == 15)
			printk("\n");
	}
	if ((z & 15) != 0)
		printk("\n");
}

/* print exact time - ditto */

static void PrTime(void)
{
	struct timeval tv;

	do_gettimeofday(&tv);
	printk("%9d:%06d: ", (int) tv.tv_sec, (int) tv.tv_usec);
}
#endif				/* DEBUG */

/* deduce resources out of POS registers */

static void getaddrs(int slot, int *base, int *memlen, int *iobase,
		     int *irq, ibmlana_medium * medium)
{
	u_char pos0, pos1;

	pos0 = mca_read_stored_pos(slot, 2);
	pos1 = mca_read_stored_pos(slot, 3);

	*base = 0xc0000 + ((pos1 & 0xf0) << 9);
	*memlen = (pos1 & 0x01) ? 0x8000 : 0x4000;
	*iobase = (pos0 & 0xe0) << 7;
	switch (pos0 & 0x06) {
	case 0:
		*irq = 5;
		break;
	case 2:
		*irq = 15;
		break;
	case 4:
		*irq = 10;
		break;
	case 6:
		*irq = 11;
		break;
	}
	*medium = (pos0 & 0x18) >> 3;
}

/* wait on register value with mask and timeout */

static int wait_timeout(struct net_device *dev, int regoffs, u16 mask,
			u16 value, int timeout)
{
	unsigned long fin = jiffies + timeout;

	while (time_before(jiffies,fin))
		if ((inw(dev->base_addr + regoffs) & mask) == value)
			return 1;

	return 0;
}


/* reset the whole board */

static void ResetBoard(struct net_device *dev)
{
	unsigned char bcmval;

	/* read original board control value */

	bcmval = inb(dev->base_addr + BCMREG);

	/* set reset bit for a while */

	bcmval |= BCMREG_RESET;
	outb(bcmval, dev->base_addr + BCMREG);
	udelay(10);
	bcmval &= ~BCMREG_RESET;
	outb(bcmval, dev->base_addr + BCMREG);

	/* switch over to RAM again */

	bcmval |= BCMREG_RAMEN | BCMREG_RAMWIN;
	outb(bcmval, dev->base_addr + BCMREG);
}

/* calculate RAM layout & set up descriptors in RAM */

static void InitDscrs(struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);
	u32 addr, baddr, raddr;
	int z;
	tda_t tda;
	rda_t rda;
	rra_t rra;

	/* initialize RAM */

	memset_io(priv->base, 0xaa,
		      dev->mem_start - dev->mem_start);	/* XXX: typo? */

	/* setup n TX descriptors - independent of RAM size */

	priv->tdastart = addr = 0;
	priv->txbufstart = baddr = sizeof(tda_t) * TXBUFCNT;
	for (z = 0; z < TXBUFCNT; z++) {
		tda.status = 0;
		tda.config = 0;
		tda.length = 0;
		tda.fragcount = 1;
		tda.startlo = baddr;
		tda.starthi = 0;
		tda.fraglength = 0;
		if (z == TXBUFCNT - 1)
			tda.link = priv->tdastart;
		else
			tda.link = addr + sizeof(tda_t);
		tda.link |= 1;
		memcpy_toio(priv->base + addr, &tda, sizeof(tda_t));
		addr += sizeof(tda_t);
		baddr += PKTSIZE;
	}

	/* calculate how many receive buffers fit into remaining memory */

	priv->rxbufcnt = (dev->mem_end - dev->mem_start - baddr) / (sizeof(rra_t) + sizeof(rda_t) + PKTSIZE);

	/* calculate receive addresses */

	priv->rrastart = raddr = priv->txbufstart + (TXBUFCNT * PKTSIZE);
	priv->rdastart = addr = priv->rrastart + (priv->rxbufcnt * sizeof(rra_t));
	priv->rxbufstart = baddr = priv->rdastart + (priv->rxbufcnt * sizeof(rda_t));

	for (z = 0; z < priv->rxbufcnt; z++) {
		rra.startlo = baddr;
		rra.starthi = 0;
		rra.cntlo = PKTSIZE >> 1;
		rra.cnthi = 0;
		memcpy_toio(priv->base + raddr, &rra, sizeof(rra_t));

		rda.status = 0;
		rda.length = 0;
		rda.startlo = 0;
		rda.starthi = 0;
		rda.seqno = 0;
		if (z < priv->rxbufcnt - 1)
			rda.link = addr + sizeof(rda_t);
		else
			rda.link = 1;
		rda.inuse = 1;
		memcpy_toio(priv->base + addr, &rda, sizeof(rda_t));

		baddr += PKTSIZE;
		raddr += sizeof(rra_t);
		addr += sizeof(rda_t);
	}

	/* initialize current pointers */

	priv->nextrxdescr = 0;
	priv->lastrxdescr = priv->rxbufcnt - 1;
	priv->nexttxdescr = 0;
	priv->currtxdescr = 0;
	priv->txusedcnt = 0;
	memset(priv->txused, 0, sizeof(priv->txused));
}

/* set up Rx + Tx descriptors in SONIC */

static int InitSONIC(struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);

	/* set up start & end of resource area */

	outw(0, SONIC_URRA);
	outw(priv->rrastart, dev->base_addr + SONIC_RSA);
	outw(priv->rrastart + (priv->rxbufcnt * sizeof(rra_t)), dev->base_addr + SONIC_REA);
	outw(priv->rrastart, dev->base_addr + SONIC_RRP);
	outw(priv->rrastart, dev->base_addr + SONIC_RWP);

	/* set EOBC so that only one packet goes into one buffer */

	outw((PKTSIZE - 4) >> 1, dev->base_addr + SONIC_EOBC);

	/* let SONIC read the first RRA descriptor */

	outw(CMDREG_RRRA, dev->base_addr + SONIC_CMDREG);
	if (!wait_timeout(dev, SONIC_CMDREG, CMDREG_RRRA, 0, 2)) {
		printk(KERN_ERR "%s: SONIC did not respond on RRRA command - giving up.", dev->name);
		return 0;
	}

	/* point SONIC to the first RDA */

	outw(0, dev->base_addr + SONIC_URDA);
	outw(priv->rdastart, dev->base_addr + SONIC_CRDA);

	/* set upper half of TDA address */

	outw(0, dev->base_addr + SONIC_UTDA);

	return 1;
}

/* stop SONIC so we can reinitialize it */

static void StopSONIC(struct net_device *dev)
{
	/* disable interrupts */

	outb(inb(dev->base_addr + BCMREG) & (~BCMREG_IEN), dev->base_addr + BCMREG);
	outb(0, dev->base_addr + SONIC_IMREG);

	/* reset the SONIC */

	outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
	udelay(10);
	outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
}

/* initialize card and SONIC for proper operation */

static void putcam(camentry_t * cams, int *camcnt, char *addr)
{
	camentry_t *pcam = cams + (*camcnt);
	u8 *uaddr = (u8 *) addr;

	pcam->index = *camcnt;
	pcam->addr0 = (((u16) uaddr[1]) << 8) | uaddr[0];
	pcam->addr1 = (((u16) uaddr[3]) << 8) | uaddr[2];
	pcam->addr2 = (((u16) uaddr[5]) << 8) | uaddr[4];
	(*camcnt)++;
}

static void InitBoard(struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);
	int camcnt;
	camentry_t cams[16];
	u32 cammask;
	struct dev_mc_list *mcptr;
	u16 rcrval;

	/* reset the SONIC */

	outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
	udelay(10);

	/* clear all spurious interrupts */

	outw(inw(dev->base_addr + SONIC_ISREG), dev->base_addr + SONIC_ISREG);

	/* set up the SONIC's bus interface - constant for this adapter -
	   must be done while the SONIC is in reset */

	outw(DCREG_USR1 | DCREG_USR0 | DCREG_WC1 | DCREG_DW32, dev->base_addr + SONIC_DCREG);
	outw(0, dev->base_addr + SONIC_DCREG2);

	/* remove reset form the SONIC */

	outw(0, dev->base_addr + SONIC_CMDREG);
	udelay(10);

	/* data sheet requires URRA to be programmed before setting up the CAM contents */

	outw(0, dev->base_addr + SONIC_URRA);

	/* program the CAM entry 0 to the device address */

	camcnt = 0;
	putcam(cams, &camcnt, dev->dev_addr);

	/* start putting the multicast addresses into the CAM list.  Stop if
	   it is full. */

	for (mcptr = dev->mc_list; mcptr != NULL; mcptr = mcptr->next) {
		putcam(cams, &camcnt, mcptr->dmi_addr);
		if (camcnt == 16)
			break;
	}

	/* calculate CAM mask */

	cammask = (1 << camcnt) - 1;

	/* feed CDA into SONIC, initialize RCR value (always get broadcasts) */

	memcpy_toio(priv->base, cams, sizeof(camentry_t) * camcnt);
	memcpy_toio(priv->base + (sizeof(camentry_t) * camcnt), &cammask, sizeof(cammask));

#ifdef DEBUG
	printk("CAM setup:\n");
	dumpmem(dev, 0, sizeof(camentry_t) * camcnt + sizeof(cammask));
#endif

	outw(0, dev->base_addr + SONIC_CAMPTR);
	outw(camcnt, dev->base_addr + SONIC_CAMCNT);
	outw(CMDREG_LCAM, dev->base_addr + SONIC_CMDREG);
	if (!wait_timeout(dev, SONIC_CMDREG, CMDREG_LCAM, 0, 2)) {
		printk(KERN_ERR "%s:SONIC did not respond on LCAM command - giving up.", dev->name);
		return;
	} else {
		/* clear interrupt condition */

		outw(ISREG_LCD, dev->base_addr + SONIC_ISREG);

#ifdef DEBUG
		printk("Loading CAM done, address pointers %04x:%04x\n",
		       inw(dev->base_addr + SONIC_URRA),
		       inw(dev->base_addr + SONIC_CAMPTR));
		{
			int z;

			printk("\n-->CAM: PTR %04x CNT %04x\n",
			       inw(dev->base_addr + SONIC_CAMPTR),
			       inw(dev->base_addr + SONIC_CAMCNT));
			outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
			for (z = 0; z < camcnt; z++) {
				outw(z, dev->base_addr + SONIC_CAMEPTR);
				printk("Entry %d: %04x %04x %04x\n", z,
				       inw(dev->base_addr + SONIC_CAMADDR0),
				       inw(dev->base_addr + SONIC_CAMADDR1),
				       inw(dev->base_addr + SONIC_CAMADDR2));
			}
			outw(0, dev->base_addr + SONIC_CMDREG);
		}
#endif
	}

	rcrval = RCREG_BRD | RCREG_LB_NONE;

	/* if still multicast addresses left or ALLMULTI is set, set the multicast
	   enable bit */

	if ((dev->flags & IFF_ALLMULTI) || (mcptr != NULL))
		rcrval |= RCREG_AMC;

	/* promiscous mode ? */

	if (dev->flags & IFF_PROMISC)
		rcrval |= RCREG_PRO;

	/* program receive mode */

	outw(rcrval, dev->base_addr + SONIC_RCREG);
#ifdef DEBUG
	printk("\nRCRVAL: %04x\n", rcrval);
#endif

	/* set up descriptors in shared memory + feed them into SONIC registers */

	InitDscrs(dev);
	if (!InitSONIC(dev))
		return;

	/* reset all pending interrupts */

	outw(0xffff, dev->base_addr + SONIC_ISREG);

	/* enable transmitter + receiver interrupts */

	outw(CMDREG_RXEN, dev->base_addr + SONIC_CMDREG);
	outw(IMREG_PRXEN | IMREG_RBEEN | IMREG_PTXEN | IMREG_TXEREN, dev->base_addr + SONIC_IMREG);

	/* turn on card interrupts */

	outb(inb(dev->base_addr + BCMREG) | BCMREG_IEN, dev->base_addr + BCMREG);

#ifdef DEBUG
	printk("Register dump after initialization:\n");
	dumpregs(dev);
#endif
}

/* start transmission of a descriptor */

static void StartTx(struct net_device *dev, int descr)
{
	ibmlana_priv *priv = netdev_priv(dev);
	int addr;

	addr = priv->tdastart + (descr * sizeof(tda_t));

	/* put descriptor address into SONIC */

	outw(addr, dev->base_addr + SONIC_CTDA);

	/* trigger transmitter */

	priv->currtxdescr = descr;
	outw(CMDREG_TXP, dev->base_addr + SONIC_CMDREG);
}

/* ------------------------------------------------------------------------
 * interrupt handler(s)
 * ------------------------------------------------------------------------ */

/* receive buffer area exhausted */

static void irqrbe_handler(struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);

	/* point the SONIC back to the RRA start */

	outw(priv->rrastart, dev->base_addr + SONIC_RRP);
	outw(priv->rrastart, dev->base_addr + SONIC_RWP);
}

/* receive interrupt */

static void irqrx_handler(struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);
	rda_t rda;
	u32 rdaaddr, lrdaaddr;

	/* loop until ... */

	while (1) {
		/* read descriptor that was next to be filled by SONIC */

		rdaaddr = priv->rdastart + (priv->nextrxdescr * sizeof(rda_t));
		lrdaaddr = priv->rdastart + (priv->lastrxdescr * sizeof(rda_t));
		memcpy_fromio(&rda, priv->base + rdaaddr, sizeof(rda_t));

		/* iron out upper word halves of fields we use - SONIC will duplicate
		   bits 0..15 to 16..31 */

		rda.status &= 0xffff;
		rda.length &= 0xffff;
		rda.startlo &= 0xffff;

		/* stop if the SONIC still owns it, i.e. there is no data for us */

		if (rda.inuse)
			break;

		/* good packet? */

		else if (rda.status & RCREG_PRX) {
			struct sk_buff *skb;

			/* fetch buffer */

			skb = dev_alloc_skb(rda.length + 2);
			if (skb == NULL)
				dev->stats.rx_dropped++;
			else {
				/* copy out data */

				memcpy_fromio(skb_put(skb, rda.length),
					       priv->base +
					       rda.startlo, rda.length);

				/* set up skb fields */

				skb->protocol = eth_type_trans(skb, dev);
				skb->ip_summed = CHECKSUM_NONE;

				/* bookkeeping */
				dev->last_rx = jiffies;
				dev->stats.rx_packets++;
				dev->stats.rx_bytes += rda.length;

				/* pass to the upper layers */
				netif_rx(skb);
			}
		}

		/* otherwise check error status bits and increase statistics */

		else {
			dev->stats.rx_errors++;
			if (rda.status & RCREG_FAER)
				dev->stats.rx_frame_errors++;
			if (rda.status & RCREG_CRCR)
				dev->stats.rx_crc_errors++;
		}

		/* descriptor processed, will become new last descriptor in queue */

		rda.link = 1;
		rda.inuse = 1;
		memcpy_toio(priv->base + rdaaddr, &rda,
			     sizeof(rda_t));

		/* set up link and EOL = 0 in currently last descriptor. Only write
		   the link field since the SONIC may currently already access the
		   other fields. */

		memcpy_toio(priv->base + lrdaaddr + 20, &rdaaddr, 4);

		/* advance indices */

		priv->lastrxdescr = priv->nextrxdescr;
		if ((++priv->nextrxdescr) >= priv->rxbufcnt)
			priv->nextrxdescr = 0;
	}
}

/* transmit interrupt */

static void irqtx_handler(struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);
	tda_t tda;

	/* fetch descriptor (we forgot the size ;-) */
	memcpy_fromio(&tda, priv->base + priv->tdastart + (priv->currtxdescr * sizeof(tda_t)), sizeof(tda_t));

	/* update statistics */
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += tda.length;

	/* update our pointers */
	priv->txused[priv->currtxdescr] = 0;
	priv->txusedcnt--;

	/* if there are more descriptors present in RAM, start them */
	if (priv->txusedcnt > 0)
		StartTx(dev, (priv->currtxdescr + 1) % TXBUFCNT);

	/* tell the upper layer we can go on transmitting */
	netif_wake_queue(dev);
}

static void irqtxerr_handler(struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);
	tda_t tda;

	/* fetch descriptor to check status */
	memcpy_fromio(&tda, priv->base + priv->tdastart + (priv->currtxdescr * sizeof(tda_t)), sizeof(tda_t));

	/* update statistics */
	dev->stats.tx_errors++;
	if (tda.status & (TCREG_NCRS | TCREG_CRSL))
		dev->stats.tx_carrier_errors++;
	if (tda.status & TCREG_EXC)
		dev->stats.tx_aborted_errors++;
	if (tda.status & TCREG_OWC)
		dev->stats.tx_window_errors++;
	if (tda.status & TCREG_FU)
		dev->stats.tx_fifo_errors++;

	/* update our pointers */
	priv->txused[priv->currtxdescr] = 0;
	priv->txusedcnt--;

	/* if there are more descriptors present in RAM, start them */
	if (priv->txusedcnt > 0)
		StartTx(dev, (priv->currtxdescr + 1) % TXBUFCNT);

	/* tell the upper layer we can go on transmitting */
	netif_wake_queue(dev);
}

/* general interrupt entry */

static irqreturn_t irq_handler(int dummy, void *device)
{
	struct net_device *dev = device;
	u16 ival;

	/* in case we're not meant... */
	if (!(inb(dev->base_addr + BCMREG) & BCMREG_IPEND))
		return IRQ_NONE;

	/* loop through the interrupt bits until everything is clear */
	while (1) {
		ival = inw(dev->base_addr + SONIC_ISREG);

		if (ival & ISREG_RBE) {
			irqrbe_handler(dev);
			outw(ISREG_RBE, dev->base_addr + SONIC_ISREG);
		}
		if (ival & ISREG_PKTRX) {
			irqrx_handler(dev);
			outw(ISREG_PKTRX, dev->base_addr + SONIC_ISREG);
		}
		if (ival & ISREG_TXDN) {
			irqtx_handler(dev);
			outw(ISREG_TXDN, dev->base_addr + SONIC_ISREG);
		}
		if (ival & ISREG_TXER) {
			irqtxerr_handler(dev);
			outw(ISREG_TXER, dev->base_addr + SONIC_ISREG);
		}
		break;
	}
	return IRQ_HANDLED;
}

/* ------------------------------------------------------------------------
 * driver methods
 * ------------------------------------------------------------------------ */

/* MCA info */

static int ibmlana_getinfo(char *buf, int slot, void *d)
{
	int len = 0, i;
	struct net_device *dev = (struct net_device *) d;
	ibmlana_priv *priv;

	/* can't say anything about an uninitialized device... */

	if (dev == NULL)
		return len;
	priv = netdev_priv(dev);

	/* print info */

	len += sprintf(buf + len, "IRQ: %d\n", priv->realirq);
	len += sprintf(buf + len, "I/O: %#lx\n", dev->base_addr);
	len += sprintf(buf + len, "Memory: %#lx-%#lx\n", dev->mem_start, dev->mem_end - 1);
	len += sprintf(buf + len, "Transceiver: %s\n", MediaNames[priv->medium]);
	len += sprintf(buf + len, "Device: %s\n", dev->name);
	len += sprintf(buf + len, "MAC address:");
	for (i = 0; i < 6; i++)
		len += sprintf(buf + len, " %02x", dev->dev_addr[i]);
	buf[len++] = '\n';
	buf[len] = 0;

	return len;
}

/* open driver.  Means also initialization and start of LANCE */

static int ibmlana_open(struct net_device *dev)
{
	int result;
	ibmlana_priv *priv = netdev_priv(dev);

	/* register resources - only necessary for IRQ */

	result = request_irq(priv->realirq, irq_handler, IRQF_SHARED | IRQF_SAMPLE_RANDOM, dev->name, dev);
	if (result != 0) {
		printk(KERN_ERR "%s: failed to register irq %d\n", dev->name, dev->irq);
		return result;
	}
	dev->irq = priv->realirq;

	/* set up the card and SONIC */
	InitBoard(dev);

	/* initialize operational flags */
	netif_start_queue(dev);
	return 0;
}

/* close driver.  Shut down board and free allocated resources */

static int ibmlana_close(struct net_device *dev)
{
	/* turn off board */

	/* release resources */
	if (dev->irq != 0)
		free_irq(dev->irq, dev);
	dev->irq = 0;
	return 0;
}

/* transmit a block. */

static int ibmlana_tx(struct sk_buff *skb, struct net_device *dev)
{
	ibmlana_priv *priv = netdev_priv(dev);
	int retval = 0, tmplen, addr;
	unsigned long flags;
	tda_t tda;
	int baddr;

	/* find out if there are free slots for a frame to transmit. If not,
	   the upper layer is in deep desperation and we simply ignore the frame. */

	if (priv->txusedcnt >= TXBUFCNT) {
		retval = -EIO;
		dev->stats.tx_dropped++;
		goto tx_done;
	}

	/* copy the frame data into the next free transmit buffer - fillup missing */
	tmplen = skb->len;
	if (tmplen < 60)
		tmplen = 60;
	baddr = priv->txbufstart + (priv->nexttxdescr * PKTSIZE);
	memcpy_toio(priv->base + baddr, skb->data, skb->len);

	/* copy filler into RAM - in case we're filling up...
	   we're filling a bit more than necessary, but that doesn't harm
	   since the buffer is far larger...
	   Sorry Linus for the filler string but I couldn't resist ;-) */

	if (tmplen > skb->len) {
		char *fill = "NetBSD is a nice OS too! ";
		unsigned int destoffs = skb->len, l = strlen(fill);

		while (destoffs < tmplen) {
			memcpy_toio(priv->base + baddr + destoffs, fill, l);
			destoffs += l;
		}
	}

	/* set up the new frame descriptor */
	addr = priv->tdastart + (priv->nexttxdescr * sizeof(tda_t));
	memcpy_fromio(&tda, priv->base + addr, sizeof(tda_t));
	tda.length = tda.fraglength = tmplen;
	memcpy_toio(priv->base + addr, &tda, sizeof(tda_t));

	/* if there were no active descriptors, trigger the SONIC */
	spin_lock_irqsave(&priv->lock, flags);

	priv->txusedcnt++;
	priv->txused[priv->nexttxdescr] = 1;

	/* are all transmission slots used up ? */
	if (priv->txusedcnt >= TXBUFCNT)
		netif_stop_queue(dev);

	if (priv->txusedcnt == 1)
		StartTx(dev, priv->nexttxdescr);
	priv->nexttxdescr = (priv->nexttxdescr + 1) % TXBUFCNT;

	spin_unlock_irqrestore(&priv->lock, flags);
tx_done:
	dev_kfree_skb(skb);
	return retval;
}

/* switch receiver mode. */

static void ibmlana_set_multicast_list(struct net_device *dev)
{
	/* first stop the SONIC... */
	StopSONIC(dev);
	/* ...then reinit it with the new flags */
	InitBoard(dev);
}

/* ------------------------------------------------------------------------
 * hardware check
 * ------------------------------------------------------------------------ */

static int ibmlana_irq;
static int ibmlana_io;
static int startslot;		/* counts through slots when probing multiple devices */

static int ibmlana_probe(struct net_device **dev_out)
{
	struct net_device *dev;
	int slot, z, rc;
	int base = 0, irq = 0, iobase = 0, memlen = 0;
	ibmlana_priv *priv;
	ibmlana_medium medium;
	DECLARE_MAC_BUF(mac);

	/* can't work without an MCA bus ;-) */
	if (MCA_bus == 0)
		return -ENODEV;

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

	dev->irq = ibmlana_irq;
	dev->base_addr = ibmlana_io;

	base = dev->mem_start;
	irq = dev->irq;

	for (slot = startslot; (slot = mca_find_adapter(IBM_LANA_ID, slot)) != -1; slot++) {
		/* deduce card addresses */
		getaddrs(slot, &base, &memlen, &iobase, &irq, &medium);

		/* slot already in use ? */
		if (mca_is_adapter_used(slot))
			continue;
		/* were we looking for something different ? */
		if (dev->irq && dev->irq != irq)
			continue;
		if (dev->mem_start && dev->mem_start != base)
			continue;
		/* found something that matches */
		break;
	}

	/* nothing found ? */
	if (slot == -1) {
		rc = (base != 0 || irq != 0) ? -ENXIO : -ENODEV;
		goto err_out;
	}

	/* announce success */
	printk(KERN_INFO "%s: IBM LAN Adapter/A found in slot %d\n", dev->name, slot + 1);

	/* try to obtain I/O range */
	if (!request_region(iobase, IBM_LANA_IORANGE, DRV_NAME)) {
		printk(KERN_ERR "%s: cannot allocate I/O range at %#x!\n", DRV_NAME, iobase);
		startslot = slot + 1;
		rc = -EBUSY;
		goto err_out;
	}

	priv = netdev_priv(dev);
	priv->slot = slot;
	priv->realirq = irq;
	priv->medium = medium;
	spin_lock_init(&priv->lock);


	/* set base + irq for this device (irq not allocated so far) */

	dev->irq = 0;
	dev->mem_start = base;
	dev->mem_end = base + memlen;
	dev->base_addr = iobase;

	priv->base = ioremap(base, memlen);
	if (!priv->base) {
		printk(KERN_ERR "%s: cannot remap memory!\n", DRV_NAME);
		startslot = slot + 1;
		rc = -EBUSY;
		goto err_out_reg;
	}

	/* make procfs entries */
	mca_set_adapter_name(slot, "IBM LAN Adapter/A");
	mca_set_adapter_procfn(slot, (MCA_ProcFn) ibmlana_getinfo, dev);

	mca_mark_as_used(slot);

	/* set methods */

	dev->open = ibmlana_open;
	dev->stop = ibmlana_close;
	dev->hard_start_xmit = ibmlana_tx;
	dev->do_ioctl = NULL;
	dev->set_multicast_list = ibmlana_set_multicast_list;
	dev->flags |= IFF_MULTICAST;

	/* copy out MAC address */

	for (z = 0; z < sizeof(dev->dev_addr); z++)
		dev->dev_addr[z] = inb(dev->base_addr + MACADDRPROM + z);

	/* print config */

	printk(KERN_INFO "%s: IRQ %d, I/O %#lx, memory %#lx-%#lx, "
	       "MAC address %s.\n",
	       dev->name, priv->realirq, dev->base_addr,
	       dev->mem_start, dev->mem_end - 1,
	       print_mac(mac, dev->dev_addr));
	printk(KERN_INFO "%s: %s medium\n", dev->name, MediaNames[priv->medium]);

	/* reset board */

	ResetBoard(dev);

	/* next probe will start at next slot */

	startslot = slot + 1;

	rc = register_netdev(dev);
	if (rc)
		goto err_out_claimed;

	*dev_out = dev;
	return 0;

err_out_claimed:
	mca_mark_as_unused(priv->slot);
	mca_set_adapter_name(priv->slot, "");
	mca_set_adapter_procfn(priv->slot, NULL, NULL);
	iounmap(priv->base);
err_out_reg:
	release_region(iobase, IBM_LANA_IORANGE);
err_out:
	free_netdev(dev);
	return rc;
}

static void ibmlana_remove_one(struct net_device *_dev)
{
	struct net_device *dev = _dev;
	ibmlana_priv *priv = netdev_priv(dev);

	unregister_netdev(dev);
	/*DeinitBoard(dev); */
	release_region(dev->base_addr, IBM_LANA_IORANGE);
	mca_mark_as_unused(priv->slot);
	mca_set_adapter_name(priv->slot, "");
	mca_set_adapter_procfn(priv->slot, NULL, NULL);
	iounmap(priv->base);
	free_netdev(dev);
}

/* ------------------------------------------------------------------------
 * modularization support
 * ------------------------------------------------------------------------ */

#define DEVMAX 5

static struct net_device *moddevs[DEVMAX];

module_param_named(irq, ibmlana_irq, int, 0);
module_param_named(io, ibmlana_io, int, 0);
MODULE_PARM_DESC(irq, "IBM LAN/A IRQ number");
MODULE_PARM_DESC(io, "IBM LAN/A I/O base address");
MODULE_LICENSE("GPL");

static int __init ibmlana_init_module(void)
{
	int z;

	startslot = 0;
	for (z = 0; z < DEVMAX; z++) {
		struct net_device *dev = NULL;

		if (ibmlana_probe(&dev))
			break;

		moddevs[z] = dev;
	}
	return (z > 0) ? 0 : -EIO;
}

static void __exit ibmlana_cleanup_module(void)
{
	int z;
	for (z = 0; z < DEVMAX; z++) {
		struct net_device *dev = moddevs[z];
		if (dev)
			ibmlana_remove_one(dev);
	}
}

module_init(ibmlana_init_module);
module_exit(ibmlana_cleanup_module);