aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/lib8390.c
blob: ed495275b57756bcc39f3c2b0b34a22d23d1c362 (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
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
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
/* 8390.c: A general NS8390 ethernet driver core for linux. */
/*
	Written 1992-94 by Donald Becker.

	Copyright 1993 United States Government as represented by the
	Director, National Security Agency.

	This software may be used and distributed according to the terms
	of the GNU General Public License, incorporated herein by reference.

	The author may be reached as becker@scyld.com, or C/O
	Scyld Computing Corporation
	410 Severn Ave., Suite 210
	Annapolis MD 21403


  This is the chip-specific code for many 8390-based ethernet adaptors.
  This is not a complete driver, it must be combined with board-specific
  code such as ne.c, wd.c, 3c503.c, etc.

  Seeing how at least eight drivers use this code, (not counting the
  PCMCIA ones either) it is easy to break some card by what seems like
  a simple innocent change. Please contact me or Donald if you think
  you have found something that needs changing. -- PG


  Changelog:

  Paul Gortmaker	: remove set_bit lock, other cleanups.
  Paul Gortmaker	: add ei_get_8390_hdr() so we can pass skb's to
			  ei_block_input() for eth_io_copy_and_sum().
  Paul Gortmaker	: exchange static int ei_pingpong for a #define,
			  also add better Tx error handling.
  Paul Gortmaker	: rewrite Rx overrun handling as per NS specs.
  Alexey Kuznetsov	: use the 8390's six bit hash multicast filter.
  Paul Gortmaker	: tweak ANK's above multicast changes a bit.
  Paul Gortmaker	: update packet statistics for v2.1.x
  Alan Cox		: support arbitary stupid port mappings on the
  			  68K Macintosh. Support >16bit I/O spaces
  Paul Gortmaker	: add kmod support for auto-loading of the 8390
			  module by all drivers that require it.
  Alan Cox		: Spinlocking work, added 'BUG_83C690'
  Paul Gortmaker	: Separate out Tx timeout code from Tx path.
  Paul Gortmaker	: Remove old unused single Tx buffer code.
  Hayato Fujiwara	: Add m32r support.
  Paul Gortmaker	: use skb_padto() instead of stack scratch area

  Sources:
  The National Semiconductor LAN Databook, and the 3Com 3c503 databook.

  */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/in.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/crc32.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>

#define NS8390_CORE
#include "8390.h"

#define BUG_83C690

/* These are the operational function interfaces to board-specific
   routines.
	void reset_8390(struct net_device *dev)
		Resets the board associated with DEV, including a hardware reset of
		the 8390.  This is only called when there is a transmit timeout, and
		it is always followed by 8390_init().
	void block_output(struct net_device *dev, int count, const unsigned char *buf,
					  int start_page)
		Write the COUNT bytes of BUF to the packet buffer at START_PAGE.  The
		"page" value uses the 8390's 256-byte pages.
	void get_8390_hdr(struct net_device *dev, struct e8390_hdr *hdr, int ring_page)
		Read the 4 byte, page aligned 8390 header. *If* there is a
		subsequent read, it will be of the rest of the packet.
	void block_input(struct net_device *dev, int count, struct sk_buff *skb, int ring_offset)
		Read COUNT bytes from the packet buffer into the skb data area. Start
		reading from RING_OFFSET, the address as the 8390 sees it.  This will always
		follow the read of the 8390 header.
*/
#define ei_reset_8390 (ei_local->reset_8390)
#define ei_block_output (ei_local->block_output)
#define ei_block_input (ei_local->block_input)
#define ei_get_8390_hdr (ei_local->get_8390_hdr)

/* use 0 for production, 1 for verification, >2 for debug */
#ifndef ei_debug
int ei_debug = 1;
#endif

/* Index to functions. */
static void ei_tx_intr(struct net_device *dev);
static void ei_tx_err(struct net_device *dev);
static void ei_tx_timeout(struct net_device *dev);
static void ei_receive(struct net_device *dev);
static void ei_rx_overrun(struct net_device *dev);

/* Routines generic to NS8390-based boards. */
static void NS8390_trigger_send(struct net_device *dev, unsigned int length,
								int start_page);
static void set_multicast_list(struct net_device *dev);
static void do_set_multicast_list(struct net_device *dev);
static void __NS8390_init(struct net_device *dev, int startp);

/*
 *	SMP and the 8390 setup.
 *
 *	The 8390 isnt exactly designed to be multithreaded on RX/TX. There is
 *	a page register that controls bank and packet buffer access. We guard
 *	this with ei_local->page_lock. Nobody should assume or set the page other
 *	than zero when the lock is not held. Lock holders must restore page 0
 *	before unlocking. Even pure readers must take the lock to protect in
 *	page 0.
 *
 *	To make life difficult the chip can also be very slow. We therefore can't
 *	just use spinlocks. For the longer lockups we disable the irq the device
 *	sits on and hold the lock. We must hold the lock because there is a dual
 *	processor case other than interrupts (get stats/set multicast list in
 *	parallel with each other and transmit).
 *
 *	Note: in theory we can just disable the irq on the card _but_ there is
 *	a latency on SMP irq delivery. So we can easily go "disable irq" "sync irqs"
 *	enter lock, take the queued irq. So we waddle instead of flying.
 *
 *	Finally by special arrangement for the purpose of being generally
 *	annoying the transmit function is called bh atomic. That places
 *	restrictions on the user context callers as disable_irq won't save
 *	them.
 *
 *	Additional explanation of problems with locking by Alan Cox:
 *
 *	"The author (me) didn't use spin_lock_irqsave because the slowness of the
 *	card means that approach caused horrible problems like losing serial data
 *	at 38400 baud on some chips. Remember many 8390 nics on PCI were ISA
 *	chips with FPGA front ends.
 *
 *	Ok the logic behind the 8390 is very simple:
 *
 *	Things to know
 *		- IRQ delivery is asynchronous to the PCI bus
 *		- Blocking the local CPU IRQ via spin locks was too slow
 *		- The chip has register windows needing locking work
 *
 *	So the path was once (I say once as people appear to have changed it
 *	in the mean time and it now looks rather bogus if the changes to use
 *	disable_irq_nosync_irqsave are disabling the local IRQ)
 *
 *
 *		Take the page lock
 *		Mask the IRQ on chip
 *		Disable the IRQ (but not mask locally- someone seems to have
 *			broken this with the lock validator stuff)
 *			[This must be _nosync as the page lock may otherwise
 *				deadlock us]
 *		Drop the page lock and turn IRQs back on
 *
 *		At this point an existing IRQ may still be running but we can't
 *		get a new one
 *
 *		Take the lock (so we know the IRQ has terminated) but don't mask
 *	the IRQs on the processor
 *		Set irqlock [for debug]
 *
 *		Transmit (slow as ****)
 *
 *		re-enable the IRQ
 *
 *
 *	We have to use disable_irq because otherwise you will get delayed
 *	interrupts on the APIC bus deadlocking the transmit path.
 *
 *	Quite hairy but the chip simply wasn't designed for SMP and you can't
 *	even ACK an interrupt without risking corrupting other parallel
 *	activities on the chip." [lkml, 25 Jul 2007]
 */



/**
 * ei_open - Open/initialize the board.
 * @dev: network device to initialize
 *
 * This routine goes all-out, setting everything
 * up anew at each open, even though many of these registers should only
 * need to be set once at boot.
 */
static int __ei_open(struct net_device *dev)
{
	unsigned long flags;
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);

	/* The card I/O part of the driver (e.g. 3c503) can hook a Tx timeout
	    wrapper that does e.g. media check & then calls ei_tx_timeout. */
	if (dev->tx_timeout == NULL)
		 dev->tx_timeout = ei_tx_timeout;
	if (dev->watchdog_timeo <= 0)
		 dev->watchdog_timeo = TX_TIMEOUT;

	/*
	 *	Grab the page lock so we own the register set, then call
	 *	the init function.
	 */

      	spin_lock_irqsave(&ei_local->page_lock, flags);
	__NS8390_init(dev, 1);
	/* Set the flag before we drop the lock, That way the IRQ arrives
	   after its set and we get no silly warnings */
	netif_start_queue(dev);
      	spin_unlock_irqrestore(&ei_local->page_lock, flags);
	ei_local->irqlock = 0;
	return 0;
}

/**
 * ei_close - shut down network device
 * @dev: network device to close
 *
 * Opposite of ei_open(). Only used when "ifconfig <devname> down" is done.
 */
static int __ei_close(struct net_device *dev)
{
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	unsigned long flags;

	/*
	 *	Hold the page lock during close
	 */

      	spin_lock_irqsave(&ei_local->page_lock, flags);
	__NS8390_init(dev, 0);
      	spin_unlock_irqrestore(&ei_local->page_lock, flags);
	netif_stop_queue(dev);
	return 0;
}

/**
 * ei_tx_timeout - handle transmit time out condition
 * @dev: network device which has apparently fallen asleep
 *
 * Called by kernel when device never acknowledges a transmit has
 * completed (or failed) - i.e. never posted a Tx related interrupt.
 */

static void ei_tx_timeout(struct net_device *dev)
{
	unsigned long e8390_base = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	int txsr, isr, tickssofar = jiffies - dev->trans_start;
	unsigned long flags;

	dev->stats.tx_errors++;

	spin_lock_irqsave(&ei_local->page_lock, flags);
	txsr = ei_inb(e8390_base+EN0_TSR);
	isr = ei_inb(e8390_base+EN0_ISR);
	spin_unlock_irqrestore(&ei_local->page_lock, flags);

	printk(KERN_DEBUG "%s: Tx timed out, %s TSR=%#2x, ISR=%#2x, t=%d.\n",
		dev->name, (txsr & ENTSR_ABT) ? "excess collisions." :
		(isr) ? "lost interrupt?" : "cable problem?", txsr, isr, tickssofar);

	if (!isr && !dev->stats.tx_packets)
	{
		/* The 8390 probably hasn't gotten on the cable yet. */
		ei_local->interface_num ^= 1;   /* Try a different xcvr.  */
	}

	/* Ugly but a reset can be slow, yet must be protected */

	disable_irq_nosync_lockdep(dev->irq);
	spin_lock(&ei_local->page_lock);

	/* Try to restart the card.  Perhaps the user has fixed something. */
	ei_reset_8390(dev);
	__NS8390_init(dev, 1);

	spin_unlock(&ei_local->page_lock);
	enable_irq_lockdep(dev->irq);
	netif_wake_queue(dev);
}

/**
 * ei_start_xmit - begin packet transmission
 * @skb: packet to be sent
 * @dev: network device to which packet is sent
 *
 * Sends a packet to an 8390 network device.
 */

static int ei_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	unsigned long e8390_base = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	int send_length = skb->len, output_page;
	unsigned long flags;
	char buf[ETH_ZLEN];
	char *data = skb->data;

	if (skb->len < ETH_ZLEN) {
		memset(buf, 0, ETH_ZLEN);	/* more efficient than doing just the needed bits */
		memcpy(buf, data, skb->len);
		send_length = ETH_ZLEN;
		data = buf;
	}

	/* Mask interrupts from the ethercard.
	   SMP: We have to grab the lock here otherwise the IRQ handler
	   on another CPU can flip window and race the IRQ mask set. We end
	   up trashing the mcast filter not disabling irqs if we don't lock */

	spin_lock_irqsave(&ei_local->page_lock, flags);
	ei_outb_p(0x00, e8390_base + EN0_IMR);
	spin_unlock_irqrestore(&ei_local->page_lock, flags);


	/*
	 *	Slow phase with lock held.
	 */

	disable_irq_nosync_lockdep_irqsave(dev->irq, &flags);

	spin_lock(&ei_local->page_lock);

	ei_local->irqlock = 1;

	/*
	 * We have two Tx slots available for use. Find the first free
	 * slot, and then perform some sanity checks. With two Tx bufs,
	 * you get very close to transmitting back-to-back packets. With
	 * only one Tx buf, the transmitter sits idle while you reload the
	 * card, leaving a substantial gap between each transmitted packet.
	 */

	if (ei_local->tx1 == 0)
	{
		output_page = ei_local->tx_start_page;
		ei_local->tx1 = send_length;
		if (ei_debug  &&  ei_local->tx2 > 0)
			printk(KERN_DEBUG "%s: idle transmitter tx2=%d, lasttx=%d, txing=%d.\n",
				dev->name, ei_local->tx2, ei_local->lasttx, ei_local->txing);
	}
	else if (ei_local->tx2 == 0)
	{
		output_page = ei_local->tx_start_page + TX_PAGES/2;
		ei_local->tx2 = send_length;
		if (ei_debug  &&  ei_local->tx1 > 0)
			printk(KERN_DEBUG "%s: idle transmitter, tx1=%d, lasttx=%d, txing=%d.\n",
				dev->name, ei_local->tx1, ei_local->lasttx, ei_local->txing);
	}
	else
	{	/* We should never get here. */
		if (ei_debug)
			printk(KERN_DEBUG "%s: No Tx buffers free! tx1=%d tx2=%d last=%d\n",
				dev->name, ei_local->tx1, ei_local->tx2, ei_local->lasttx);
		ei_local->irqlock = 0;
		netif_stop_queue(dev);
		ei_outb_p(ENISR_ALL, e8390_base + EN0_IMR);
		spin_unlock(&ei_local->page_lock);
		enable_irq_lockdep_irqrestore(dev->irq, &flags);
		dev->stats.tx_errors++;
		return 1;
	}

	/*
	 * Okay, now upload the packet and trigger a send if the transmitter
	 * isn't already sending. If it is busy, the interrupt handler will
	 * trigger the send later, upon receiving a Tx done interrupt.
	 */

	ei_block_output(dev, send_length, data, output_page);

	if (! ei_local->txing)
	{
		ei_local->txing = 1;
		NS8390_trigger_send(dev, send_length, output_page);
		dev->trans_start = jiffies;
		if (output_page == ei_local->tx_start_page)
		{
			ei_local->tx1 = -1;
			ei_local->lasttx = -1;
		}
		else
		{
			ei_local->tx2 = -1;
			ei_local->lasttx = -2;
		}
	}
	else ei_local->txqueue++;

	if (ei_local->tx1  &&  ei_local->tx2)
		netif_stop_queue(dev);
	else
		netif_start_queue(dev);

	/* Turn 8390 interrupts back on. */
	ei_local->irqlock = 0;
	ei_outb_p(ENISR_ALL, e8390_base + EN0_IMR);

	spin_unlock(&ei_local->page_lock);
	enable_irq_lockdep_irqrestore(dev->irq, &flags);

	dev_kfree_skb (skb);
	dev->stats.tx_bytes += send_length;

	return 0;
}

/**
 * ei_interrupt - handle the interrupts from an 8390
 * @irq: interrupt number
 * @dev_id: a pointer to the net_device
 *
 * Handle the ether interface interrupts. We pull packets from
 * the 8390 via the card specific functions and fire them at the networking
 * stack. We also handle transmit completions and wake the transmit path if
 * necessary. We also update the counters and do other housekeeping as
 * needed.
 */

static irqreturn_t __ei_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	unsigned long e8390_base = dev->base_addr;
	int interrupts, nr_serviced = 0;
	struct ei_device *ei_local = netdev_priv(dev);

	/*
	 *	Protect the irq test too.
	 */

	spin_lock(&ei_local->page_lock);

	if (ei_local->irqlock)
	{
#if 1 /* This might just be an interrupt for a PCI device sharing this line */
		/* The "irqlock" check is only for testing. */
		printk(ei_local->irqlock
			   ? "%s: Interrupted while interrupts are masked! isr=%#2x imr=%#2x.\n"
			   : "%s: Reentering the interrupt handler! isr=%#2x imr=%#2x.\n",
			   dev->name, ei_inb_p(e8390_base + EN0_ISR),
			   ei_inb_p(e8390_base + EN0_IMR));
#endif
		spin_unlock(&ei_local->page_lock);
		return IRQ_NONE;
	}

	/* Change to page 0 and read the intr status reg. */
	ei_outb_p(E8390_NODMA+E8390_PAGE0, e8390_base + E8390_CMD);
	if (ei_debug > 3)
		printk(KERN_DEBUG "%s: interrupt(isr=%#2.2x).\n", dev->name,
			   ei_inb_p(e8390_base + EN0_ISR));

	/* !!Assumption!! -- we stay in page 0.	 Don't break this. */
	while ((interrupts = ei_inb_p(e8390_base + EN0_ISR)) != 0
		   && ++nr_serviced < MAX_SERVICE)
	{
		if (!netif_running(dev)) {
			printk(KERN_WARNING "%s: interrupt from stopped card\n", dev->name);
			/* rmk - acknowledge the interrupts */
			ei_outb_p(interrupts, e8390_base + EN0_ISR);
			interrupts = 0;
			break;
		}
		if (interrupts & ENISR_OVER)
			ei_rx_overrun(dev);
		else if (interrupts & (ENISR_RX+ENISR_RX_ERR))
		{
			/* Got a good (?) packet. */
			ei_receive(dev);
		}
		/* Push the next to-transmit packet through. */
		if (interrupts & ENISR_TX)
			ei_tx_intr(dev);
		else if (interrupts & ENISR_TX_ERR)
			ei_tx_err(dev);

		if (interrupts & ENISR_COUNTERS)
		{
			dev->stats.rx_frame_errors += ei_inb_p(e8390_base + EN0_COUNTER0);
			dev->stats.rx_crc_errors   += ei_inb_p(e8390_base + EN0_COUNTER1);
			dev->stats.rx_missed_errors+= ei_inb_p(e8390_base + EN0_COUNTER2);
			ei_outb_p(ENISR_COUNTERS, e8390_base + EN0_ISR); /* Ack intr. */
		}

		/* Ignore any RDC interrupts that make it back to here. */
		if (interrupts & ENISR_RDC)
		{
			ei_outb_p(ENISR_RDC, e8390_base + EN0_ISR);
		}

		ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base + E8390_CMD);
	}

	if (interrupts && ei_debug)
	{
		ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base + E8390_CMD);
		if (nr_serviced >= MAX_SERVICE)
		{
			/* 0xFF is valid for a card removal */
			if(interrupts!=0xFF)
				printk(KERN_WARNING "%s: Too much work at interrupt, status %#2.2x\n",
				   dev->name, interrupts);
			ei_outb_p(ENISR_ALL, e8390_base + EN0_ISR); /* Ack. most intrs. */
		} else {
			printk(KERN_WARNING "%s: unknown interrupt %#2x\n", dev->name, interrupts);
			ei_outb_p(0xff, e8390_base + EN0_ISR); /* Ack. all intrs. */
		}
	}
	spin_unlock(&ei_local->page_lock);
	return IRQ_RETVAL(nr_serviced > 0);
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void __ei_poll(struct net_device *dev)
{
	disable_irq_lockdep(dev->irq);
	__ei_interrupt(dev->irq, dev);
	enable_irq_lockdep(dev->irq);
}
#endif

/**
 * ei_tx_err - handle transmitter error
 * @dev: network device which threw the exception
 *
 * A transmitter error has happened. Most likely excess collisions (which
 * is a fairly normal condition). If the error is one where the Tx will
 * have been aborted, we try and send another one right away, instead of
 * letting the failed packet sit and collect dust in the Tx buffer. This
 * is a much better solution as it avoids kernel based Tx timeouts, and
 * an unnecessary card reset.
 *
 * Called with lock held.
 */

static void ei_tx_err(struct net_device *dev)
{
	unsigned long e8390_base = dev->base_addr;
	unsigned char txsr = ei_inb_p(e8390_base+EN0_TSR);
	unsigned char tx_was_aborted = txsr & (ENTSR_ABT+ENTSR_FU);

#ifdef VERBOSE_ERROR_DUMP
	printk(KERN_DEBUG "%s: transmitter error (%#2x): ", dev->name, txsr);
	if (txsr & ENTSR_ABT)
		printk("excess-collisions ");
	if (txsr & ENTSR_ND)
		printk("non-deferral ");
	if (txsr & ENTSR_CRS)
		printk("lost-carrier ");
	if (txsr & ENTSR_FU)
		printk("FIFO-underrun ");
	if (txsr & ENTSR_CDH)
		printk("lost-heartbeat ");
	printk("\n");
#endif

	ei_outb_p(ENISR_TX_ERR, e8390_base + EN0_ISR); /* Ack intr. */

	if (tx_was_aborted)
		ei_tx_intr(dev);
	else
	{
		dev->stats.tx_errors++;
		if (txsr & ENTSR_CRS) dev->stats.tx_carrier_errors++;
		if (txsr & ENTSR_CDH) dev->stats.tx_heartbeat_errors++;
		if (txsr & ENTSR_OWC) dev->stats.tx_window_errors++;
	}
}

/**
 * ei_tx_intr - transmit interrupt handler
 * @dev: network device for which tx intr is handled
 *
 * We have finished a transmit: check for errors and then trigger the next
 * packet to be sent. Called with lock held.
 */

static void ei_tx_intr(struct net_device *dev)
{
	unsigned long e8390_base = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	int status = ei_inb(e8390_base + EN0_TSR);

	ei_outb_p(ENISR_TX, e8390_base + EN0_ISR); /* Ack intr. */

	/*
	 * There are two Tx buffers, see which one finished, and trigger
	 * the send of another one if it exists.
	 */
	ei_local->txqueue--;

	if (ei_local->tx1 < 0)
	{
		if (ei_local->lasttx != 1 && ei_local->lasttx != -1)
			printk(KERN_ERR "%s: bogus last_tx_buffer %d, tx1=%d.\n",
				ei_local->name, ei_local->lasttx, ei_local->tx1);
		ei_local->tx1 = 0;
		if (ei_local->tx2 > 0)
		{
			ei_local->txing = 1;
			NS8390_trigger_send(dev, ei_local->tx2, ei_local->tx_start_page + 6);
			dev->trans_start = jiffies;
			ei_local->tx2 = -1,
			ei_local->lasttx = 2;
		}
		else ei_local->lasttx = 20, ei_local->txing = 0;
	}
	else if (ei_local->tx2 < 0)
	{
		if (ei_local->lasttx != 2  &&  ei_local->lasttx != -2)
			printk("%s: bogus last_tx_buffer %d, tx2=%d.\n",
				ei_local->name, ei_local->lasttx, ei_local->tx2);
		ei_local->tx2 = 0;
		if (ei_local->tx1 > 0)
		{
			ei_local->txing = 1;
			NS8390_trigger_send(dev, ei_local->tx1, ei_local->tx_start_page);
			dev->trans_start = jiffies;
			ei_local->tx1 = -1;
			ei_local->lasttx = 1;
		}
		else
			ei_local->lasttx = 10, ei_local->txing = 0;
	}
//	else printk(KERN_WARNING "%s: unexpected TX-done interrupt, lasttx=%d.\n",
//			dev->name, ei_local->lasttx);

	/* Minimize Tx latency: update the statistics after we restart TXing. */
	if (status & ENTSR_COL)
		dev->stats.collisions++;
	if (status & ENTSR_PTX)
		dev->stats.tx_packets++;
	else
	{
		dev->stats.tx_errors++;
		if (status & ENTSR_ABT)
		{
			dev->stats.tx_aborted_errors++;
			dev->stats.collisions += 16;
		}
		if (status & ENTSR_CRS)
			dev->stats.tx_carrier_errors++;
		if (status & ENTSR_FU)
			dev->stats.tx_fifo_errors++;
		if (status & ENTSR_CDH)
			dev->stats.tx_heartbeat_errors++;
		if (status & ENTSR_OWC)
			dev->stats.tx_window_errors++;
	}
	netif_wake_queue(dev);
}

/**
 * ei_receive - receive some packets
 * @dev: network device with which receive will be run
 *
 * We have a good packet(s), get it/them out of the buffers.
 * Called with lock held.
 */

static void ei_receive(struct net_device *dev)
{
	unsigned long e8390_base = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	unsigned char rxing_page, this_frame, next_frame;
	unsigned short current_offset;
	int rx_pkt_count = 0;
	struct e8390_pkt_hdr rx_frame;
	int num_rx_pages = ei_local->stop_page-ei_local->rx_start_page;

	while (++rx_pkt_count < 10)
	{
		int pkt_len, pkt_stat;

		/* Get the rx page (incoming packet pointer). */
		ei_outb_p(E8390_NODMA+E8390_PAGE1, e8390_base + E8390_CMD);
		rxing_page = ei_inb_p(e8390_base + EN1_CURPAG);
		ei_outb_p(E8390_NODMA+E8390_PAGE0, e8390_base + E8390_CMD);

		/* Remove one frame from the ring.  Boundary is always a page behind. */
		this_frame = ei_inb_p(e8390_base + EN0_BOUNDARY) + 1;
		if (this_frame >= ei_local->stop_page)
			this_frame = ei_local->rx_start_page;

		/* Someday we'll omit the previous, iff we never get this message.
		   (There is at least one clone claimed to have a problem.)

		   Keep quiet if it looks like a card removal. One problem here
		   is that some clones crash in roughly the same way.
		 */
		if (ei_debug > 0  &&  this_frame != ei_local->current_page && (this_frame!=0x0 || rxing_page!=0xFF))
			printk(KERN_ERR "%s: mismatched read page pointers %2x vs %2x.\n",
				   dev->name, this_frame, ei_local->current_page);

		if (this_frame == rxing_page)	/* Read all the frames? */
			break;				/* Done for now */

		current_offset = this_frame << 8;
		ei_get_8390_hdr(dev, &rx_frame, this_frame);

		pkt_len = rx_frame.count - sizeof(struct e8390_pkt_hdr);
		pkt_stat = rx_frame.status;

		next_frame = this_frame + 1 + ((pkt_len+4)>>8);

		/* Check for bogosity warned by 3c503 book: the status byte is never
		   written.  This happened a lot during testing! This code should be
		   cleaned up someday. */
		if (rx_frame.next != next_frame
			&& rx_frame.next != next_frame + 1
			&& rx_frame.next != next_frame - num_rx_pages
			&& rx_frame.next != next_frame + 1 - num_rx_pages) {
			ei_local->current_page = rxing_page;
			ei_outb(ei_local->current_page-1, e8390_base+EN0_BOUNDARY);
			dev->stats.rx_errors++;
			continue;
		}

		if (pkt_len < 60  ||  pkt_len > 1518)
		{
			if (ei_debug)
				printk(KERN_DEBUG "%s: bogus packet size: %d, status=%#2x nxpg=%#2x.\n",
					   dev->name, rx_frame.count, rx_frame.status,
					   rx_frame.next);
			dev->stats.rx_errors++;
			dev->stats.rx_length_errors++;
		}
		 else if ((pkt_stat & 0x0F) == ENRSR_RXOK)
		{
			struct sk_buff *skb;

			skb = dev_alloc_skb(pkt_len+2);
			if (skb == NULL)
			{
				if (ei_debug > 1)
					printk(KERN_DEBUG "%s: Couldn't allocate a sk_buff of size %d.\n",
						   dev->name, pkt_len);
				dev->stats.rx_dropped++;
				break;
			}
			else
			{
				skb_reserve(skb,2);	/* IP headers on 16 byte boundaries */
				skb_put(skb, pkt_len);	/* Make room */
				ei_block_input(dev, pkt_len, skb, current_offset + sizeof(rx_frame));
				skb->protocol=eth_type_trans(skb,dev);
				netif_rx(skb);
				dev->last_rx = jiffies;
				dev->stats.rx_packets++;
				dev->stats.rx_bytes += pkt_len;
				if (pkt_stat & ENRSR_PHY)
					dev->stats.multicast++;
			}
		}
		else
		{
			if (ei_debug)
				printk(KERN_DEBUG "%s: bogus packet: status=%#2x nxpg=%#2x size=%d\n",
					   dev->name, rx_frame.status, rx_frame.next,
					   rx_frame.count);
			dev->stats.rx_errors++;
			/* NB: The NIC counts CRC, frame and missed errors. */
			if (pkt_stat & ENRSR_FO)
				dev->stats.rx_fifo_errors++;
		}
		next_frame = rx_frame.next;

		/* This _should_ never happen: it's here for avoiding bad clones. */
		if (next_frame >= ei_local->stop_page) {
			printk("%s: next frame inconsistency, %#2x\n", dev->name,
				   next_frame);
			next_frame = ei_local->rx_start_page;
		}
		ei_local->current_page = next_frame;
		ei_outb_p(next_frame-1, e8390_base+EN0_BOUNDARY);
	}

	/* We used to also ack ENISR_OVER here, but that would sometimes mask
	   a real overrun, leaving the 8390 in a stopped state with rec'vr off. */
	ei_outb_p(ENISR_RX+ENISR_RX_ERR, e8390_base+EN0_ISR);
	return;
}

/**
 * ei_rx_overrun - handle receiver overrun
 * @dev: network device which threw exception
 *
 * We have a receiver overrun: we have to kick the 8390 to get it started
 * again. Problem is that you have to kick it exactly as NS prescribes in
 * the updated datasheets, or "the NIC may act in an unpredictable manner."
 * This includes causing "the NIC to defer indefinitely when it is stopped
 * on a busy network."  Ugh.
 * Called with lock held. Don't call this with the interrupts off or your
 * computer will hate you - it takes 10ms or so.
 */

static void ei_rx_overrun(struct net_device *dev)
{
	unsigned long e8390_base = dev->base_addr;
	unsigned char was_txing, must_resend = 0;

	/*
	 * Record whether a Tx was in progress and then issue the
	 * stop command.
	 */
	was_txing = ei_inb_p(e8390_base+E8390_CMD) & E8390_TRANS;
	ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD);

	if (ei_debug > 1)
		printk(KERN_DEBUG "%s: Receiver overrun.\n", dev->name);
	dev->stats.rx_over_errors++;

	/*
	 * Wait a full Tx time (1.2ms) + some guard time, NS says 1.6ms total.
	 * Early datasheets said to poll the reset bit, but now they say that
	 * it "is not a reliable indicator and subsequently should be ignored."
	 * We wait at least 10ms.
	 */

	mdelay(10);

	/*
	 * Reset RBCR[01] back to zero as per magic incantation.
	 */
	ei_outb_p(0x00, e8390_base+EN0_RCNTLO);
	ei_outb_p(0x00, e8390_base+EN0_RCNTHI);

	/*
	 * See if any Tx was interrupted or not. According to NS, this
	 * step is vital, and skipping it will cause no end of havoc.
	 */

	if (was_txing)
	{
		unsigned char tx_completed = ei_inb_p(e8390_base+EN0_ISR) & (ENISR_TX+ENISR_TX_ERR);
		if (!tx_completed)
			must_resend = 1;
	}

	/*
	 * Have to enter loopback mode and then restart the NIC before
	 * you are allowed to slurp packets up off the ring.
	 */
	ei_outb_p(E8390_TXOFF, e8390_base + EN0_TXCR);
	ei_outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START, e8390_base + E8390_CMD);

	/*
	 * Clear the Rx ring of all the debris, and ack the interrupt.
	 */
	ei_receive(dev);
	ei_outb_p(ENISR_OVER, e8390_base+EN0_ISR);

	/*
	 * Leave loopback mode, and resend any packet that got stopped.
	 */
	ei_outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR);
	if (must_resend)
    		ei_outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START + E8390_TRANS, e8390_base + E8390_CMD);
}

/*
 *	Collect the stats. This is called unlocked and from several contexts.
 */

static struct net_device_stats *get_stats(struct net_device *dev)
{
	unsigned long ioaddr = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	unsigned long flags;

	/* If the card is stopped, just return the present stats. */
	if (!netif_running(dev))
		return &dev->stats;

	spin_lock_irqsave(&ei_local->page_lock,flags);
	/* Read the counter registers, assuming we are in page 0. */
	dev->stats.rx_frame_errors += ei_inb_p(ioaddr + EN0_COUNTER0);
	dev->stats.rx_crc_errors   += ei_inb_p(ioaddr + EN0_COUNTER1);
	dev->stats.rx_missed_errors+= ei_inb_p(ioaddr + EN0_COUNTER2);
	spin_unlock_irqrestore(&ei_local->page_lock, flags);

	return &dev->stats;
}

/*
 * Form the 64 bit 8390 multicast table from the linked list of addresses
 * associated with this dev structure.
 */

static inline void make_mc_bits(u8 *bits, struct net_device *dev)
{
	struct dev_mc_list *dmi;

	for (dmi=dev->mc_list; dmi; dmi=dmi->next)
	{
		u32 crc;
		if (dmi->dmi_addrlen != ETH_ALEN)
		{
			printk(KERN_INFO "%s: invalid multicast address length given.\n", dev->name);
			continue;
		}
		crc = ether_crc(ETH_ALEN, dmi->dmi_addr);
		/*
		 * The 8390 uses the 6 most significant bits of the
		 * CRC to index the multicast table.
		 */
		bits[crc>>29] |= (1<<((crc>>26)&7));
	}
}

/**
 * do_set_multicast_list - set/clear multicast filter
 * @dev: net device for which multicast filter is adjusted
 *
 *	Set or clear the multicast filter for this adaptor. May be called
 *	from a BH in 2.1.x. Must be called with lock held.
 */

static void do_set_multicast_list(struct net_device *dev)
{
	unsigned long e8390_base = dev->base_addr;
	int i;
	struct ei_device *ei_local = (struct ei_device*)netdev_priv(dev);

	if (!(dev->flags&(IFF_PROMISC|IFF_ALLMULTI)))
	{
		memset(ei_local->mcfilter, 0, 8);
		if (dev->mc_list)
			make_mc_bits(ei_local->mcfilter, dev);
	}
	else
		memset(ei_local->mcfilter, 0xFF, 8);	/* mcast set to accept-all */

	/*
	 * DP8390 manuals don't specify any magic sequence for altering
	 * the multicast regs on an already running card. To be safe, we
	 * ensure multicast mode is off prior to loading up the new hash
	 * table. If this proves to be not enough, we can always resort
	 * to stopping the NIC, loading the table and then restarting.
	 *
	 * Bug Alert!  The MC regs on the SMC 83C690 (SMC Elite and SMC
	 * Elite16) appear to be write-only. The NS 8390 data sheet lists
	 * them as r/w so this is a bug.  The SMC 83C790 (SMC Ultra and
	 * Ultra32 EISA) appears to have this bug fixed.
	 */

	if (netif_running(dev))
		ei_outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR);
	ei_outb_p(E8390_NODMA + E8390_PAGE1, e8390_base + E8390_CMD);
	for(i = 0; i < 8; i++)
	{
		ei_outb_p(ei_local->mcfilter[i], e8390_base + EN1_MULT_SHIFT(i));
#ifndef BUG_83C690
		if(ei_inb_p(e8390_base + EN1_MULT_SHIFT(i))!=ei_local->mcfilter[i])
			printk(KERN_ERR "Multicast filter read/write mismap %d\n",i);
#endif
	}
	ei_outb_p(E8390_NODMA + E8390_PAGE0, e8390_base + E8390_CMD);

  	if(dev->flags&IFF_PROMISC)
  		ei_outb_p(E8390_RXCONFIG | 0x18, e8390_base + EN0_RXCR);
	else if(dev->flags&IFF_ALLMULTI || dev->mc_list)
  		ei_outb_p(E8390_RXCONFIG | 0x08, e8390_base + EN0_RXCR);
  	else
  		ei_outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR);
 }

/*
 *	Called without lock held. This is invoked from user context and may
 *	be parallel to just about everything else. Its also fairly quick and
 *	not called too often. Must protect against both bh and irq users
 */

static void set_multicast_list(struct net_device *dev)
{
	unsigned long flags;
	struct ei_device *ei_local = (struct ei_device*)netdev_priv(dev);

	spin_lock_irqsave(&ei_local->page_lock, flags);
	do_set_multicast_list(dev);
	spin_unlock_irqrestore(&ei_local->page_lock, flags);
}

/**
 * ethdev_setup - init rest of 8390 device struct
 * @dev: network device structure to init
 *
 * Initialize the rest of the 8390 device structure.  Do NOT __init
 * this, as it is used by 8390 based modular drivers too.
 */

static void ethdev_setup(struct net_device *dev)
{
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	if (ei_debug > 1)
		printk(version);

	dev->hard_start_xmit = &ei_start_xmit;
	dev->get_stats	= get_stats;
	dev->set_multicast_list = &set_multicast_list;

	ether_setup(dev);

	spin_lock_init(&ei_local->page_lock);
}

/**
 * alloc_ei_netdev - alloc_etherdev counterpart for 8390
 * @size: extra bytes to allocate
 *
 * Allocate 8390-specific net_device.
 */
static struct net_device *____alloc_ei_netdev(int size)
{
	return alloc_netdev(sizeof(struct ei_device) + size, "eth%d",
				ethdev_setup);
}




/* This page of functions should be 8390 generic */
/* Follow National Semi's recommendations for initializing the "NIC". */

/**
 * NS8390_init - initialize 8390 hardware
 * @dev: network device to initialize
 * @startp: boolean.  non-zero value to initiate chip processing
 *
 *	Must be called with lock held.
 */

static void __NS8390_init(struct net_device *dev, int startp)
{
	unsigned long e8390_base = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) netdev_priv(dev);
	int i;
	int endcfg = ei_local->word16
	    ? (0x48 | ENDCFG_WTS | (ei_local->bigendian ? ENDCFG_BOS : 0))
	    : 0x48;

	if(sizeof(struct e8390_pkt_hdr)!=4)
    		panic("8390.c: header struct mispacked\n");
	/* Follow National Semi's recommendations for initing the DP83902. */
	ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD); /* 0x21 */
	ei_outb_p(endcfg, e8390_base + EN0_DCFG);	/* 0x48 or 0x49 */
	/* Clear the remote byte count registers. */
	ei_outb_p(0x00,  e8390_base + EN0_RCNTLO);
	ei_outb_p(0x00,  e8390_base + EN0_RCNTHI);
	/* Set to monitor and loopback mode -- this is vital!. */
	ei_outb_p(E8390_RXOFF, e8390_base + EN0_RXCR); /* 0x20 */
	ei_outb_p(E8390_TXOFF, e8390_base + EN0_TXCR); /* 0x02 */
	/* Set the transmit page and receive ring. */
	ei_outb_p(ei_local->tx_start_page, e8390_base + EN0_TPSR);
	ei_local->tx1 = ei_local->tx2 = 0;
	ei_outb_p(ei_local->rx_start_page, e8390_base + EN0_STARTPG);
	ei_outb_p(ei_local->stop_page-1, e8390_base + EN0_BOUNDARY);	/* 3c503 says 0x3f,NS0x26*/
	ei_local->current_page = ei_local->rx_start_page;		/* assert boundary+1 */
	ei_outb_p(ei_local->stop_page, e8390_base + EN0_STOPPG);
	/* Clear the pending interrupts and mask. */
	ei_outb_p(0xFF, e8390_base + EN0_ISR);
	ei_outb_p(0x00,  e8390_base + EN0_IMR);

	/* Copy the station address into the DS8390 registers. */

	ei_outb_p(E8390_NODMA + E8390_PAGE1 + E8390_STOP, e8390_base+E8390_CMD); /* 0x61 */
	for(i = 0; i < 6; i++)
	{
		ei_outb_p(dev->dev_addr[i], e8390_base + EN1_PHYS_SHIFT(i));
		if (ei_debug > 1 && ei_inb_p(e8390_base + EN1_PHYS_SHIFT(i))!=dev->dev_addr[i])
			printk(KERN_ERR "Hw. address read/write mismap %d\n",i);
	}

	ei_outb_p(ei_local->rx_start_page, e8390_base + EN1_CURPAG);
	ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD);

	netif_start_queue(dev);
	ei_local->tx1 = ei_local->tx2 = 0;
	ei_local->txing = 0;

	if (startp)
	{
		ei_outb_p(0xff,  e8390_base + EN0_ISR);
		ei_outb_p(ENISR_ALL,  e8390_base + EN0_IMR);
		ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base+E8390_CMD);
		ei_outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR); /* xmit on. */
		/* 3c503 TechMan says rxconfig only after the NIC is started. */
		ei_outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR); /* rx on,  */
		do_set_multicast_list(dev);	/* (re)load the mcast table */
	}
}

/* Trigger a transmit start, assuming the length is valid.
   Always called with the page lock held */

static void NS8390_trigger_send(struct net_device *dev, unsigned int length,
								int start_page)
{
	unsigned long e8390_base = dev->base_addr;
 	struct ei_device *ei_local __attribute((unused)) = (struct ei_device *) netdev_priv(dev);

	ei_outb_p(E8390_NODMA+E8390_PAGE0, e8390_base+E8390_CMD);

	if (ei_inb_p(e8390_base + E8390_CMD) & E8390_TRANS)
	{
		printk(KERN_WARNING "%s: trigger_send() called with the transmitter busy.\n",
			dev->name);
		return;
	}
	ei_outb_p(length & 0xff, e8390_base + EN0_TCNTLO);
	ei_outb_p(length >> 8, e8390_base + EN0_TCNTHI);
	ei_outb_p(start_page, e8390_base + EN0_TPSR);
	ei_outb_p(E8390_NODMA+E8390_TRANS+E8390_START, e8390_base+E8390_CMD);
}