summaryrefslogtreecommitdiff
path: root/drivers/net/3c503.c
blob: 5b732988d49389c9811ae2d5c19c87ebdda92807 (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
/* 3c503.c: A shared-memory NS8390 ethernet driver 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 driver should work with the 3c503 and 3c503/16.  It should be used
    in shared memory mode for best performance, although it may also work
    in programmed-I/O mode.

    Sources:
    EtherLink II Technical Reference Manual,
    EtherLink II/16 Technical Reference Manual Supplement,
    3Com Corporation, 5400 Bayfront Plaza, Santa Clara CA 95052-8145

    The Crynwr 3c503 packet driver.

    Changelog:

    Paul Gortmaker	: add support for the 2nd 8kB of RAM on 16 bit cards.
    Paul Gortmaker	: multiple card support for module users.
    rjohnson@analogic.com : Fix up PIO interface for efficient operation.
    Jeff Garzik		: ethtool support

*/

#define DRV_NAME	"3c503"
#define DRV_VERSION	"1.10a"
#define DRV_RELDATE	"11/17/2001"


static const char version[] =
    DRV_NAME ".c:v" DRV_VERSION " " DRV_RELDATE "  Donald Becker (becker@scyld.com)\n";

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/init.h>
#include <linux/ethtool.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/byteorder.h>

#include "8390.h"
#include "3c503.h"
#define WRD_COUNT 4

static int el2_pio_probe(struct net_device *dev);
static int el2_probe1(struct net_device *dev, int ioaddr);

/* A zero-terminated list of I/O addresses to be probed in PIO mode. */
static unsigned int netcard_portlist[] __initdata =
	{ 0x300,0x310,0x330,0x350,0x250,0x280,0x2a0,0x2e0,0};

#define EL2_IO_EXTENT	16

static int el2_open(struct net_device *dev);
static int el2_close(struct net_device *dev);
static void el2_reset_8390(struct net_device *dev);
static void el2_init_card(struct net_device *dev);
static void el2_block_output(struct net_device *dev, int count,
			     const unsigned char *buf, int start_page);
static void el2_block_input(struct net_device *dev, int count, struct sk_buff *skb,
			   int ring_offset);
static void el2_get_8390_hdr(struct net_device *dev, struct e8390_pkt_hdr *hdr,
			 int ring_page);
static const struct ethtool_ops netdev_ethtool_ops;


/* This routine probes for a memory-mapped 3c503 board by looking for
   the "location register" at the end of the jumpered boot PROM space.
   This works even if a PROM isn't there.

   If the ethercard isn't found there is an optional probe for
   ethercard jumpered to programmed-I/O mode.
   */
static int __init do_el2_probe(struct net_device *dev)
{
    int *addr, addrs[] = { 0xddffe, 0xd9ffe, 0xcdffe, 0xc9ffe, 0};
    int base_addr = dev->base_addr;
    int irq = dev->irq;

    if (base_addr > 0x1ff)	/* Check a single specified location. */
	return el2_probe1(dev, base_addr);
    else if (base_addr != 0)		/* Don't probe at all. */
	return -ENXIO;

    for (addr = addrs; *addr; addr++) {
	void __iomem *p = ioremap(*addr, 1);
	unsigned base_bits;
	int i;

	if (!p)
		continue;
	base_bits = readb(p);
	iounmap(p);
	i = ffs(base_bits) - 1;
	if (i == -1 || base_bits != (1 << i))
	    continue;
	if (el2_probe1(dev, netcard_portlist[i]) == 0)
	    return 0;
	dev->irq = irq;
    }
#if ! defined(no_probe_nonshared_memory)
    return el2_pio_probe(dev);
#else
    return -ENODEV;
#endif
}

/*  Try all of the locations that aren't obviously empty.  This touches
    a lot of locations, and is much riskier than the code above. */
static int __init
el2_pio_probe(struct net_device *dev)
{
    int i;
    int base_addr = dev->base_addr;
    int irq = dev->irq;

    if (base_addr > 0x1ff)	/* Check a single specified location. */
	return el2_probe1(dev, base_addr);
    else if (base_addr != 0)	/* Don't probe at all. */
	return -ENXIO;

    for (i = 0; netcard_portlist[i]; i++) {
	if (el2_probe1(dev, netcard_portlist[i]) == 0)
	    return 0;
	dev->irq = irq;
    }

    return -ENODEV;
}

#ifndef MODULE
struct net_device * __init el2_probe(int unit)
{
	struct net_device *dev = alloc_eip_netdev();
	int err;

	if (!dev)
		return ERR_PTR(-ENOMEM);

	sprintf(dev->name, "eth%d", unit);
	netdev_boot_setup_check(dev);

	err = do_el2_probe(dev);
	if (err)
		goto out;
	return dev;
out:
	free_netdev(dev);
	return ERR_PTR(err);
}
#endif

static const struct net_device_ops el2_netdev_ops = {
	.ndo_open		= el2_open,
	.ndo_stop		= el2_close,

	.ndo_start_xmit		= eip_start_xmit,
	.ndo_tx_timeout		= eip_tx_timeout,
	.ndo_get_stats		= eip_get_stats,
	.ndo_set_multicast_list = eip_set_multicast_list,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_set_mac_address 	= eth_mac_addr,
	.ndo_change_mtu		= eth_change_mtu,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller 	= eip_poll,
#endif
};

/* Probe for the Etherlink II card at I/O port base IOADDR,
   returning non-zero on success.  If found, set the station
   address and memory parameters in DEVICE. */
static int __init
el2_probe1(struct net_device *dev, int ioaddr)
{
    int i, iobase_reg, membase_reg, saved_406, wordlength, retval;
    static unsigned version_printed;
    unsigned long vendor_id;

    if (!request_region(ioaddr, EL2_IO_EXTENT, DRV_NAME))
	return -EBUSY;

    if (!request_region(ioaddr + 0x400, 8, DRV_NAME)) {
	retval = -EBUSY;
	goto out;
    }

    /* Reset and/or avoid any lurking NE2000 */
    if (inb(ioaddr + 0x408) == 0xff) {
    	mdelay(1);
	retval = -ENODEV;
	goto out1;
    }

    /* We verify that it's a 3C503 board by checking the first three octets
       of its ethernet address. */
    iobase_reg = inb(ioaddr+0x403);
    membase_reg = inb(ioaddr+0x404);
    /* ASIC location registers should be 0 or have only a single bit set. */
    if ((iobase_reg  & (iobase_reg - 1)) ||
	(membase_reg & (membase_reg - 1))) {
	retval = -ENODEV;
	goto out1;
    }
    saved_406 = inb_p(ioaddr + 0x406);
    outb_p(ECNTRL_RESET|ECNTRL_THIN, ioaddr + 0x406); /* Reset it... */
    outb_p(ECNTRL_THIN, ioaddr + 0x406);
    /* Map the station addr PROM into the lower I/O ports. We now check
       for both the old and new 3Com prefix */
    outb(ECNTRL_SAPROM|ECNTRL_THIN, ioaddr + 0x406);
    vendor_id = inb(ioaddr)*0x10000 + inb(ioaddr + 1)*0x100 + inb(ioaddr + 2);
    if ((vendor_id != OLD_3COM_ID) && (vendor_id != NEW_3COM_ID)) {
	/* Restore the register we frobbed. */
	outb(saved_406, ioaddr + 0x406);
	retval = -ENODEV;
	goto out1;
    }

    if (ei_debug  &&  version_printed++ == 0)
	pr_debug("%s", version);

    dev->base_addr = ioaddr;

    pr_info("%s: 3c503 at i/o base %#3x, node ", dev->name, ioaddr);

    /* Retrieve and print the ethernet address. */
    for (i = 0; i < 6; i++)
	dev->dev_addr[i] = inb(ioaddr + i);
    pr_cont("%pM", dev->dev_addr);

    /* Map the 8390 back into the window. */
    outb(ECNTRL_THIN, ioaddr + 0x406);

    /* Check for EL2/16 as described in tech. man. */
    outb_p(E8390_PAGE0, ioaddr + E8390_CMD);
    outb_p(0, ioaddr + EN0_DCFG);
    outb_p(E8390_PAGE2, ioaddr + E8390_CMD);
    wordlength = inb_p(ioaddr + EN0_DCFG) & ENDCFG_WTS;
    outb_p(E8390_PAGE0, ioaddr + E8390_CMD);

    /* Probe for, turn on and clear the board's shared memory. */
    if (ei_debug > 2)
	pr_cont(" memory jumpers %2.2x ", membase_reg);
    outb(EGACFR_NORM, ioaddr + 0x405);	/* Enable RAM */

    /* This should be probed for (or set via an ioctl()) at run-time.
       Right now we use a sleazy hack to pass in the interface number
       at boot-time via the low bits of the mem_end field.  That value is
       unused, and the low bits would be discarded even if it was used. */
#if defined(EI8390_THICK) || defined(EL2_AUI)
    ei_status.interface_num = 1;
#else
    ei_status.interface_num = dev->mem_end & 0xf;
#endif
    pr_cont(", using %sternal xcvr.\n", ei_status.interface_num == 0 ? "in" : "ex");

    if ((membase_reg & 0xf0) == 0) {
	dev->mem_start = 0;
	ei_status.name = "3c503-PIO";
	ei_status.mem = NULL;
    } else {
	dev->mem_start = ((membase_reg & 0xc0) ? 0xD8000 : 0xC8000) +
	    ((membase_reg & 0xA0) ? 0x4000 : 0);
#define EL2_MEMSIZE (EL2_MB1_STOP_PG - EL2_MB1_START_PG)*256
	ei_status.mem = ioremap(dev->mem_start, EL2_MEMSIZE);

#ifdef EL2MEMTEST
	/* This has never found an error, but someone might care.
	   Note that it only tests the 2nd 8kB on 16kB 3c503/16
	   cards between card addr. 0x2000 and 0x3fff. */
	{			/* Check the card's memory. */
	    void __iomem *mem_base = ei_status.mem;
	    unsigned int test_val = 0xbbadf00d;
	    writel(0xba5eba5e, mem_base);
	    for (i = sizeof(test_val); i < EL2_MEMSIZE; i+=sizeof(test_val)) {
		writel(test_val, mem_base + i);
		if (readl(mem_base) != 0xba5eba5e ||
		    readl(mem_base + i) != test_val) {
		    pr_warning("3c503: memory failure or memory address conflict.\n");
		    dev->mem_start = 0;
		    ei_status.name = "3c503-PIO";
		    iounmap(mem_base);
		    ei_status.mem = NULL;
		    break;
		}
		test_val += 0x55555555;
		writel(0, mem_base + i);
	    }
	}
#endif  /* EL2MEMTEST */

	if (dev->mem_start)
		dev->mem_end = dev->mem_start + EL2_MEMSIZE;

	if (wordlength) {	/* No Tx pages to skip over to get to Rx */
		ei_status.priv = 0;
		ei_status.name = "3c503/16";
	} else {
		ei_status.priv = TX_PAGES * 256;
		ei_status.name = "3c503";
	}
    }

    /*
	Divide up the memory on the card. This is the same regardless of
	whether shared-mem or PIO is used. For 16 bit cards (16kB RAM),
	we use the entire 8k of bank1 for an Rx ring. We only use 3k
	of the bank0 for 2 full size Tx packet slots. For 8 bit cards,
	(8kB RAM) we use 3kB of bank1 for two Tx slots, and the remaining
	5kB for an Rx ring.  */

    if (wordlength) {
	ei_status.tx_start_page = EL2_MB0_START_PG;
	ei_status.rx_start_page = EL2_MB1_START_PG;
    } else {
	ei_status.tx_start_page = EL2_MB1_START_PG;
	ei_status.rx_start_page = EL2_MB1_START_PG + TX_PAGES;
    }

    /* Finish setting the board's parameters. */
    ei_status.stop_page = EL2_MB1_STOP_PG;
    ei_status.word16 = wordlength;
    ei_status.reset_8390 = el2_reset_8390;
    ei_status.get_8390_hdr = el2_get_8390_hdr;
    ei_status.block_input = el2_block_input;
    ei_status.block_output = el2_block_output;

    if (dev->irq == 2)
	dev->irq = 9;
    else if (dev->irq > 5 && dev->irq != 9) {
	pr_warning("3c503: configured interrupt %d invalid, will use autoIRQ.\n",
	       dev->irq);
	dev->irq = 0;
    }

    ei_status.saved_irq = dev->irq;

    dev->netdev_ops = &el2_netdev_ops;
    dev->ethtool_ops = &netdev_ethtool_ops;

    retval = register_netdev(dev);
    if (retval)
	goto out1;

    if (dev->mem_start)
	pr_info("%s: %s - %dkB RAM, 8kB shared mem window at %#6lx-%#6lx.\n",
		dev->name, ei_status.name, (wordlength+1)<<3,
		dev->mem_start, dev->mem_end-1);

    else
    {
	ei_status.tx_start_page = EL2_MB1_START_PG;
	ei_status.rx_start_page = EL2_MB1_START_PG + TX_PAGES;
	pr_info("%s: %s, %dkB RAM, using programmed I/O (REJUMPER for SHARED MEMORY).\n",
	       dev->name, ei_status.name, (wordlength+1)<<3);
    }
    release_region(ioaddr + 0x400, 8);
    return 0;
out1:
    release_region(ioaddr + 0x400, 8);
out:
    release_region(ioaddr, EL2_IO_EXTENT);
    return retval;
}

static irqreturn_t el2_probe_interrupt(int irq, void *seen)
{
	*(bool *)seen = true;
	return IRQ_HANDLED;
}

static int
el2_open(struct net_device *dev)
{
    int retval;

    if (dev->irq < 2) {
	static const int irqlist[] = {5, 9, 3, 4, 0};
	const int *irqp = irqlist;

	outb(EGACFR_NORM, E33G_GACFR);	/* Enable RAM and interrupts. */
	do {
		bool seen;

		retval = request_irq(*irqp, el2_probe_interrupt, 0,
				     dev->name, &seen);
		if (retval == -EBUSY)
			continue;
		if (retval < 0)
			goto err_disable;

		/* Twinkle the interrupt, and check if it's seen. */
		seen = false;
		smp_wmb();
		outb_p(0x04 << ((*irqp == 9) ? 2 : *irqp), E33G_IDCFR);
		outb_p(0x00, E33G_IDCFR);
		msleep(1);
		free_irq(*irqp, &seen);
		if (!seen)
			continue;

		retval = request_irq(dev->irq = *irqp, eip_interrupt, 0,
				     dev->name, dev);
		if (retval == -EBUSY)
			continue;
		if (retval < 0)
			goto err_disable;
		break;
	} while (*++irqp);

	if (*irqp == 0) {
	err_disable:
	    outb(EGACFR_IRQOFF, E33G_GACFR);	/* disable interrupts. */
	    return -EAGAIN;
	}
    } else {
	if ((retval = request_irq(dev->irq, eip_interrupt, 0, dev->name, dev))) {
	    return retval;
	}
    }

    el2_init_card(dev);
    eip_open(dev);
    return 0;
}

static int
el2_close(struct net_device *dev)
{
    free_irq(dev->irq, dev);
    dev->irq = ei_status.saved_irq;
    outb(EGACFR_IRQOFF, E33G_GACFR);	/* disable interrupts. */

    eip_close(dev);
    return 0;
}

/* This is called whenever we have a unrecoverable failure:
       transmit timeout
       Bad ring buffer packet header
 */
static void
el2_reset_8390(struct net_device *dev)
{
    if (ei_debug > 1) {
	pr_debug("%s: Resetting the 3c503 board...", dev->name);
	pr_cont(" %#lx=%#02x %#lx=%#02x %#lx=%#02x...", E33G_IDCFR, inb(E33G_IDCFR),
	       E33G_CNTRL, inb(E33G_CNTRL), E33G_GACFR, inb(E33G_GACFR));
    }
    outb_p(ECNTRL_RESET|ECNTRL_THIN, E33G_CNTRL);
    ei_status.txing = 0;
    outb_p(ei_status.interface_num==0 ? ECNTRL_THIN : ECNTRL_AUI, E33G_CNTRL);
    el2_init_card(dev);
    if (ei_debug > 1)
	pr_cont("done\n");
}

/* Initialize the 3c503 GA registers after a reset. */
static void
el2_init_card(struct net_device *dev)
{
    /* Unmap the station PROM and select the DIX or BNC connector. */
    outb_p(ei_status.interface_num==0 ? ECNTRL_THIN : ECNTRL_AUI, E33G_CNTRL);

    /* Set ASIC copy of rx's first and last+1 buffer pages */
    /* These must be the same as in the 8390. */
    outb(ei_status.rx_start_page, E33G_STARTPG);
    outb(ei_status.stop_page,  E33G_STOPPG);

    /* Point the vector pointer registers somewhere ?harmless?. */
    outb(0xff, E33G_VP2);	/* Point at the ROM restart location 0xffff0 */
    outb(0xff, E33G_VP1);
    outb(0x00, E33G_VP0);
    /* Turn off all interrupts until we're opened. */
    outb_p(0x00,  dev->base_addr + EN0_IMR);
    /* Enable IRQs iff started. */
    outb(EGACFR_NORM, E33G_GACFR);

    /* Set the interrupt line. */
    outb_p((0x04 << (dev->irq == 9 ? 2 : dev->irq)), E33G_IDCFR);
    outb_p((WRD_COUNT << 1), E33G_DRQCNT);	/* Set burst size to 8 */
    outb_p(0x20, E33G_DMAAH);	/* Put a valid addr in the GA DMA */
    outb_p(0x00, E33G_DMAAL);
    return;			/* We always succeed */
}

/*
 * Either use the shared memory (if enabled on the board) or put the packet
 * out through the ASIC FIFO.
 */
static void
el2_block_output(struct net_device *dev, int count,
		 const unsigned char *buf, int start_page)
{
    unsigned short int *wrd;
    int boguscount;		/* timeout counter */
    unsigned short word;	/* temporary for better machine code */
    void __iomem *base = ei_status.mem;

    if (ei_status.word16)      /* Tx packets go into bank 0 on EL2/16 card */
	outb(EGACFR_RSEL|EGACFR_TCM, E33G_GACFR);
    else
	outb(EGACFR_NORM, E33G_GACFR);

    if (base) {	/* Shared memory transfer */
	memcpy_toio(base + ((start_page - ei_status.tx_start_page) << 8),
			buf, count);
	outb(EGACFR_NORM, E33G_GACFR);	/* Back to bank1 in case on bank0 */
	return;
    }

/*
 *  No shared memory, put the packet out the other way.
 *  Set up then start the internal memory transfer to Tx Start Page
 */

    word = (unsigned short)start_page;
    outb(word&0xFF, E33G_DMAAH);
    outb(word>>8, E33G_DMAAL);

    outb_p((ei_status.interface_num ? ECNTRL_AUI : ECNTRL_THIN ) | ECNTRL_OUTPUT
	   | ECNTRL_START, E33G_CNTRL);

/*
 *  Here I am going to write data to the FIFO as quickly as possible.
 *  Note that E33G_FIFOH is defined incorrectly. It is really
 *  E33G_FIFOL, the lowest port address for both the byte and
 *  word write. Variable 'count' is NOT checked. Caller must supply a
 *  valid count. Note that I may write a harmless extra byte to the
 *  8390 if the byte-count was not even.
 */
    wrd = (unsigned short int *) buf;
    count  = (count + 1) >> 1;
    for(;;)
    {
        boguscount = 0x1000;
        while ((inb(E33G_STATUS) & ESTAT_DPRDY) == 0)
        {
            if(!boguscount--)
            {
                pr_notice("%s: FIFO blocked in el2_block_output.\n", dev->name);
                el2_reset_8390(dev);
                goto blocked;
            }
        }
        if(count > WRD_COUNT)
        {
            outsw(E33G_FIFOH, wrd, WRD_COUNT);
            wrd   += WRD_COUNT;
            count -= WRD_COUNT;
        }
        else
        {
            outsw(E33G_FIFOH, wrd, count);
            break;
        }
    }
    blocked:;
    outb_p(ei_status.interface_num==0 ? ECNTRL_THIN : ECNTRL_AUI, E33G_CNTRL);
}

/* Read the 4 byte, page aligned 8390 specific header. */
static void
el2_get_8390_hdr(struct net_device *dev, struct e8390_pkt_hdr *hdr, int ring_page)
{
    int boguscount;
    void __iomem *base = ei_status.mem;
    unsigned short word;

    if (base) {       /* Use the shared memory. */
	void __iomem *hdr_start = base + ((ring_page - EL2_MB1_START_PG)<<8);
	memcpy_fromio(hdr, hdr_start, sizeof(struct e8390_pkt_hdr));
	hdr->count = le16_to_cpu(hdr->count);
	return;
    }

/*
 *  No shared memory, use programmed I/O.
 */

    word = (unsigned short)ring_page;
    outb(word&0xFF, E33G_DMAAH);
    outb(word>>8, E33G_DMAAL);

    outb_p((ei_status.interface_num == 0 ? ECNTRL_THIN : ECNTRL_AUI) | ECNTRL_INPUT
	   | ECNTRL_START, E33G_CNTRL);
    boguscount = 0x1000;
    while ((inb(E33G_STATUS) & ESTAT_DPRDY) == 0)
    {
        if(!boguscount--)
        {
            pr_notice("%s: FIFO blocked in el2_get_8390_hdr.\n", dev->name);
            memset(hdr, 0x00, sizeof(struct e8390_pkt_hdr));
            el2_reset_8390(dev);
            goto blocked;
        }
    }
    insw(E33G_FIFOH, hdr, (sizeof(struct e8390_pkt_hdr))>> 1);
    blocked:;
    outb_p(ei_status.interface_num == 0 ? ECNTRL_THIN : ECNTRL_AUI, E33G_CNTRL);
}


static void
el2_block_input(struct net_device *dev, int count, struct sk_buff *skb, int ring_offset)
{
    int boguscount = 0;
    void __iomem *base = ei_status.mem;
    unsigned short int *buf;
    unsigned short word;

    /* Maybe enable shared memory just be to be safe... nahh.*/
    if (base) {	/* Use the shared memory. */
	ring_offset -= (EL2_MB1_START_PG<<8);
	if (ring_offset + count > EL2_MEMSIZE) {
	    /* We must wrap the input move. */
	    int semi_count = EL2_MEMSIZE - ring_offset;
	    memcpy_fromio(skb->data, base + ring_offset, semi_count);
	    count -= semi_count;
	    memcpy_fromio(skb->data + semi_count, base + ei_status.priv, count);
	} else {
		memcpy_fromio(skb->data, base + ring_offset, count);
	}
	return;
    }

/*
 *  No shared memory, use programmed I/O.
 */
    word = (unsigned short) ring_offset;
    outb(word>>8, E33G_DMAAH);
    outb(word&0xFF, E33G_DMAAL);

    outb_p((ei_status.interface_num == 0 ? ECNTRL_THIN : ECNTRL_AUI) | ECNTRL_INPUT
	   | ECNTRL_START, E33G_CNTRL);

/*
 *  Here I also try to get data as fast as possible. I am betting that I
 *  can read one extra byte without clobbering anything in the kernel because
 *  this would only occur on an odd byte-count and allocation of skb->data
 *  is word-aligned. Variable 'count' is NOT checked. Caller must check
 *  for a valid count.
 *  [This is currently quite safe.... but if one day the 3c503 explodes
 *   you know where to come looking ;)]
 */

    buf =  (unsigned short int *) skb->data;
    count =  (count + 1) >> 1;
    for(;;)
    {
        boguscount = 0x1000;
        while ((inb(E33G_STATUS) & ESTAT_DPRDY) == 0)
        {
            if(!boguscount--)
            {
                pr_notice("%s: FIFO blocked in el2_block_input.\n", dev->name);
                el2_reset_8390(dev);
                goto blocked;
            }
        }
        if(count > WRD_COUNT)
        {
            insw(E33G_FIFOH, buf, WRD_COUNT);
            buf   += WRD_COUNT;
            count -= WRD_COUNT;
        }
        else
        {
            insw(E33G_FIFOH, buf, count);
            break;
        }
    }
    blocked:;
    outb_p(ei_status.interface_num == 0 ? ECNTRL_THIN : ECNTRL_AUI, E33G_CNTRL);
}


static void netdev_get_drvinfo(struct net_device *dev,
			       struct ethtool_drvinfo *info)
{
	strcpy(info->driver, DRV_NAME);
	strcpy(info->version, DRV_VERSION);
	sprintf(info->bus_info, "ISA 0x%lx", dev->base_addr);
}

static const struct ethtool_ops netdev_ethtool_ops = {
	.get_drvinfo		= netdev_get_drvinfo,
};

#ifdef MODULE
#define MAX_EL2_CARDS	4	/* Max number of EL2 cards per module */

static struct net_device *dev_el2[MAX_EL2_CARDS];
static int io[MAX_EL2_CARDS];
static int irq[MAX_EL2_CARDS];
static int xcvr[MAX_EL2_CARDS];	/* choose int. or ext. xcvr */
module_param_array(io, int, NULL, 0);
module_param_array(irq, int, NULL, 0);
module_param_array(xcvr, int, NULL, 0);
MODULE_PARM_DESC(io, "I/O base address(es)");
MODULE_PARM_DESC(irq, "IRQ number(s) (assigned)");
MODULE_PARM_DESC(xcvr, "transceiver(s) (0=internal, 1=external)");
MODULE_DESCRIPTION("3Com ISA EtherLink II, II/16 (3c503, 3c503/16) driver");
MODULE_LICENSE("GPL");

/* This is set up so that only a single autoprobe takes place per call.
ISA device autoprobes on a running machine are not recommended. */
int __init
init_module(void)
{
	struct net_device *dev;
	int this_dev, found = 0;

	for (this_dev = 0; this_dev < MAX_EL2_CARDS; this_dev++) {
		if (io[this_dev] == 0)  {
			if (this_dev != 0) break; /* only autoprobe 1st one */
			pr_notice("3c503.c: Presently autoprobing (not recommended) for a single card.\n");
		}
		dev = alloc_eip_netdev();
		if (!dev)
			break;
		dev->irq = irq[this_dev];
		dev->base_addr = io[this_dev];
		dev->mem_end = xcvr[this_dev];	/* low 4bits = xcvr sel. */
		if (do_el2_probe(dev) == 0) {
			dev_el2[found++] = dev;
			continue;
		}
		free_netdev(dev);
		pr_warning("3c503.c: No 3c503 card found (i/o = 0x%x).\n", io[this_dev]);
		break;
	}
	if (found)
		return 0;
	return -ENXIO;
}

static void cleanup_card(struct net_device *dev)
{
	/* NB: el2_close() handles free_irq */
	release_region(dev->base_addr, EL2_IO_EXTENT);
	if (ei_status.mem)
		iounmap(ei_status.mem);
}

void __exit
cleanup_module(void)
{
	int this_dev;

	for (this_dev = 0; this_dev < MAX_EL2_CARDS; this_dev++) {
		struct net_device *dev = dev_el2[this_dev];
		if (dev) {
			unregister_netdev(dev);
			cleanup_card(dev);
			free_netdev(dev);
		}
	}
}
#endif /* MODULE */