1 /*
2  *  linux/drivers/acorn/net/ether1.c
3  *
4  *  Copyright (C) 1996-2000 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  *  Acorn ether1 driver (82586 chip) for Acorn machines
11  *
12  * We basically keep two queues in the cards memory - one for transmit
13  * and one for receive.  Each has a head and a tail.  The head is where
14  * we/the chip adds packets to be transmitted/received, and the tail
15  * is where the transmitter has got to/where the receiver will stop.
16  * Both of these queues are circular, and since the chip is running
17  * all the time, we have to be careful when we modify the pointers etc
18  * so that the buffer memory contents is valid all the time.
19  *
20  * Change log:
21  * 1.00	RMK			Released
22  * 1.01	RMK	19/03/1996	Transfers the last odd byte onto/off of the card now.
23  * 1.02	RMK	25/05/1997	Added code to restart RU if it goes not ready
24  * 1.03	RMK	14/09/1997	Cleaned up the handling of a reset during the TX interrupt.
25  *				Should prevent lockup.
26  * 1.04 RMK	17/09/1997	Added more info when initialsation of chip goes wrong.
27  *				TDR now only reports failure when chip reports non-zero
28  *				TDR time-distance.
29  * 1.05	RMK	31/12/1997	Removed calls to dev_tint for 2.1
30  * 1.06	RMK	10/02/2000	Updated for 2.3.43
31  * 1.07	RMK	13/05/2000	Updated for 2.3.99-pre8
32  */
33 
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/types.h>
37 #include <linux/fcntl.h>
38 #include <linux/interrupt.h>
39 #include <linux/ioport.h>
40 #include <linux/in.h>
41 #include <linux/slab.h>
42 #include <linux/string.h>
43 #include <linux/errno.h>
44 #include <linux/device.h>
45 #include <linux/init.h>
46 #include <linux/netdevice.h>
47 #include <linux/etherdevice.h>
48 #include <linux/skbuff.h>
49 #include <linux/bitops.h>
50 
51 #include <asm/io.h>
52 #include <asm/dma.h>
53 #include <asm/ecard.h>
54 
55 #define __ETHER1_C
56 #include "ether1.h"
57 
58 static unsigned int net_debug = NET_DEBUG;
59 
60 #define BUFFER_SIZE	0x10000
61 #define TX_AREA_START	0x00100
62 #define TX_AREA_END	0x05000
63 #define RX_AREA_START	0x05000
64 #define RX_AREA_END	0x0fc00
65 
66 static int ether1_open(struct net_device *dev);
67 static int ether1_sendpacket(struct sk_buff *skb, struct net_device *dev);
68 static irqreturn_t ether1_interrupt(int irq, void *dev_id);
69 static int ether1_close(struct net_device *dev);
70 static void ether1_setmulticastlist(struct net_device *dev);
71 static void ether1_timeout(struct net_device *dev);
72 
73 /* ------------------------------------------------------------------------- */
74 
75 static char version[] = "ether1 ethernet driver (c) 2000 Russell King v1.07\n";
76 
77 #define BUS_16 16
78 #define BUS_8  8
79 
80 /* ------------------------------------------------------------------------- */
81 
82 #define DISABLEIRQS 1
83 #define NORMALIRQS  0
84 
85 #define ether1_readw(dev, addr, type, offset, svflgs) ether1_inw_p (dev, addr + (int)(&((type *)0)->offset), svflgs)
86 #define ether1_writew(dev, val, addr, type, offset, svflgs) ether1_outw_p (dev, val, addr + (int)(&((type *)0)->offset), svflgs)
87 
88 static inline unsigned short
89 ether1_inw_p (struct net_device *dev, int addr, int svflgs)
90 {
91 	unsigned long flags;
92 	unsigned short ret;
93 
94 	if (svflgs)
95 		local_irq_save (flags);
96 
97 	writeb(addr >> 12, REG_PAGE);
98 	ret = readw(ETHER1_RAM + ((addr & 4095) << 1));
99 	if (svflgs)
100 		local_irq_restore (flags);
101 	return ret;
102 }
103 
104 static inline void
105 ether1_outw_p (struct net_device *dev, unsigned short val, int addr, int svflgs)
106 {
107 	unsigned long flags;
108 
109 	if (svflgs)
110 		local_irq_save (flags);
111 
112 	writeb(addr >> 12, REG_PAGE);
113 	writew(val, ETHER1_RAM + ((addr & 4095) << 1));
114 	if (svflgs)
115 		local_irq_restore (flags);
116 }
117 
118 /*
119  * Some inline assembler to allow fast transfers on to/off of the card.
120  * Since this driver depends on some features presented by the ARM
121  * specific architecture, and that you can't configure this driver
122  * without specifiing ARM mode, this is not a problem.
123  *
124  * This routine is essentially an optimised memcpy from the card's
125  * onboard RAM to kernel memory.
126  */
127 static void
128 ether1_writebuffer (struct net_device *dev, void *data, unsigned int start, unsigned int length)
129 {
130 	unsigned int page, thislen, offset;
131 	void __iomem *addr;
132 
133 	offset = start & 4095;
134 	page = start >> 12;
135 	addr = ETHER1_RAM + (offset << 1);
136 
137 	if (offset + length > 4096)
138 		thislen = 4096 - offset;
139 	else
140 		thislen = length;
141 
142 	do {
143 		int used;
144 
145 		writeb(page, REG_PAGE);
146 		length -= thislen;
147 
148 		__asm__ __volatile__(
149 	"subs	%3, %3, #2\n\
150 	bmi	2f\n\
151 1:	ldr	%0, [%1], #2\n\
152 	mov	%0, %0, lsl #16\n\
153 	orr	%0, %0, %0, lsr #16\n\
154 	str	%0, [%2], #4\n\
155 	subs	%3, %3, #2\n\
156 	bmi	2f\n\
157 	ldr	%0, [%1], #2\n\
158 	mov	%0, %0, lsl #16\n\
159 	orr	%0, %0, %0, lsr #16\n\
160 	str	%0, [%2], #4\n\
161 	subs	%3, %3, #2\n\
162 	bmi	2f\n\
163 	ldr	%0, [%1], #2\n\
164 	mov	%0, %0, lsl #16\n\
165 	orr	%0, %0, %0, lsr #16\n\
166 	str	%0, [%2], #4\n\
167 	subs	%3, %3, #2\n\
168 	bmi	2f\n\
169 	ldr	%0, [%1], #2\n\
170 	mov	%0, %0, lsl #16\n\
171 	orr	%0, %0, %0, lsr #16\n\
172 	str	%0, [%2], #4\n\
173 	subs	%3, %3, #2\n\
174 	bpl	1b\n\
175 2:	adds	%3, %3, #1\n\
176 	ldreqb	%0, [%1]\n\
177 	streqb	%0, [%2]"
178 		: "=&r" (used), "=&r" (data)
179 		: "r"  (addr), "r" (thislen), "1" (data));
180 
181 		addr = ETHER1_RAM;
182 
183 		thislen = length;
184 		if (thislen > 4096)
185 			thislen = 4096;
186 		page++;
187 	} while (thislen);
188 }
189 
190 static void
191 ether1_readbuffer (struct net_device *dev, void *data, unsigned int start, unsigned int length)
192 {
193 	unsigned int page, thislen, offset;
194 	void __iomem *addr;
195 
196 	offset = start & 4095;
197 	page = start >> 12;
198 	addr = ETHER1_RAM + (offset << 1);
199 
200 	if (offset + length > 4096)
201 		thislen = 4096 - offset;
202 	else
203 		thislen = length;
204 
205 	do {
206 		int used;
207 
208 		writeb(page, REG_PAGE);
209 		length -= thislen;
210 
211 		__asm__ __volatile__(
212 	"subs	%3, %3, #2\n\
213 	bmi	2f\n\
214 1:	ldr	%0, [%2], #4\n\
215 	strb	%0, [%1], #1\n\
216 	mov	%0, %0, lsr #8\n\
217 	strb	%0, [%1], #1\n\
218 	subs	%3, %3, #2\n\
219 	bmi	2f\n\
220 	ldr	%0, [%2], #4\n\
221 	strb	%0, [%1], #1\n\
222 	mov	%0, %0, lsr #8\n\
223 	strb	%0, [%1], #1\n\
224 	subs	%3, %3, #2\n\
225 	bmi	2f\n\
226 	ldr	%0, [%2], #4\n\
227 	strb	%0, [%1], #1\n\
228 	mov	%0, %0, lsr #8\n\
229 	strb	%0, [%1], #1\n\
230 	subs	%3, %3, #2\n\
231 	bmi	2f\n\
232 	ldr	%0, [%2], #4\n\
233 	strb	%0, [%1], #1\n\
234 	mov	%0, %0, lsr #8\n\
235 	strb	%0, [%1], #1\n\
236 	subs	%3, %3, #2\n\
237 	bpl	1b\n\
238 2:	adds	%3, %3, #1\n\
239 	ldreqb	%0, [%2]\n\
240 	streqb	%0, [%1]"
241 		: "=&r" (used), "=&r" (data)
242 		: "r"  (addr), "r" (thislen), "1" (data));
243 
244 		addr = ETHER1_RAM;
245 
246 		thislen = length;
247 		if (thislen > 4096)
248 			thislen = 4096;
249 		page++;
250 	} while (thislen);
251 }
252 
253 static int
254 ether1_ramtest(struct net_device *dev, unsigned char byte)
255 {
256 	unsigned char *buffer = kmalloc (BUFFER_SIZE, GFP_KERNEL);
257 	int i, ret = BUFFER_SIZE;
258 	int max_errors = 15;
259 	int bad = -1;
260 	int bad_start = 0;
261 
262 	if (!buffer)
263 		return 1;
264 
265 	memset (buffer, byte, BUFFER_SIZE);
266 	ether1_writebuffer (dev, buffer, 0, BUFFER_SIZE);
267 	memset (buffer, byte ^ 0xff, BUFFER_SIZE);
268 	ether1_readbuffer (dev, buffer, 0, BUFFER_SIZE);
269 
270 	for (i = 0; i < BUFFER_SIZE; i++) {
271 		if (buffer[i] != byte) {
272 			if (max_errors >= 0 && bad != buffer[i]) {
273 				if (bad != -1)
274 					printk ("\n");
275 				printk (KERN_CRIT "%s: RAM failed with (%02X instead of %02X) at 0x%04X",
276 					dev->name, buffer[i], byte, i);
277 				ret = -ENODEV;
278 				max_errors --;
279 				bad = buffer[i];
280 				bad_start = i;
281 			}
282 		} else {
283 			if (bad != -1) {
284 			    	if (bad_start == i - 1)
285 					printk ("\n");
286 				else
287 					printk (" - 0x%04X\n", i - 1);
288 				bad = -1;
289 			}
290 		}
291 	}
292 
293 	if (bad != -1)
294 		printk (" - 0x%04X\n", BUFFER_SIZE);
295 	kfree (buffer);
296 
297 	return ret;
298 }
299 
300 static int
301 ether1_reset (struct net_device *dev)
302 {
303 	writeb(CTRL_RST|CTRL_ACK, REG_CONTROL);
304 	return BUS_16;
305 }
306 
307 static int
308 ether1_init_2(struct net_device *dev)
309 {
310 	int i;
311 	dev->mem_start = 0;
312 
313 	i = ether1_ramtest (dev, 0x5a);
314 
315 	if (i > 0)
316 		i = ether1_ramtest (dev, 0x1e);
317 
318 	if (i <= 0)
319 	    	return -ENODEV;
320 
321 	dev->mem_end = i;
322 	return 0;
323 }
324 
325 /*
326  * These are the structures that are loaded into the ether RAM card to
327  * initialise the 82586
328  */
329 
330 /* at 0x0100 */
331 #define NOP_ADDR	(TX_AREA_START)
332 #define NOP_SIZE	(0x06)
333 static nop_t  init_nop  = {
334 	0,
335 	CMD_NOP,
336 	NOP_ADDR
337 };
338 
339 /* at 0x003a */
340 #define TDR_ADDR	(0x003a)
341 #define TDR_SIZE	(0x08)
342 static tdr_t  init_tdr	= {
343 	0,
344 	CMD_TDR | CMD_INTR,
345 	NOP_ADDR,
346 	0
347 };
348 
349 /* at 0x002e */
350 #define MC_ADDR		(0x002e)
351 #define MC_SIZE		(0x0c)
352 static mc_t   init_mc   = {
353 	0,
354 	CMD_SETMULTICAST,
355 	TDR_ADDR,
356 	0,
357 	{ { 0, } }
358 };
359 
360 /* at 0x0022 */
361 #define SA_ADDR		(0x0022)
362 #define SA_SIZE		(0x0c)
363 static sa_t   init_sa   = {
364 	0,
365 	CMD_SETADDRESS,
366 	MC_ADDR,
367 	{ 0, }
368 };
369 
370 /* at 0x0010 */
371 #define CFG_ADDR	(0x0010)
372 #define CFG_SIZE	(0x12)
373 static cfg_t  init_cfg  = {
374 	0,
375 	CMD_CONFIG,
376 	SA_ADDR,
377 	8,
378 	8,
379 	CFG8_SRDY,
380 	CFG9_PREAMB8 | CFG9_ADDRLENBUF | CFG9_ADDRLEN(6),
381 	0,
382 	0x60,
383 	0,
384 	CFG13_RETRY(15) | CFG13_SLOTH(2),
385 	0,
386 };
387 
388 /* at 0x0000 */
389 #define SCB_ADDR	(0x0000)
390 #define SCB_SIZE	(0x10)
391 static scb_t  init_scb  = {
392 	0,
393 	SCB_CMDACKRNR | SCB_CMDACKCNA | SCB_CMDACKFR | SCB_CMDACKCX,
394 	CFG_ADDR,
395 	RX_AREA_START,
396 	0,
397 	0,
398 	0,
399 	0
400 };
401 
402 /* at 0xffee */
403 #define ISCP_ADDR	(0xffee)
404 #define ISCP_SIZE	(0x08)
405 static iscp_t init_iscp = {
406 	1,
407 	SCB_ADDR,
408 	0x0000,
409 	0x0000
410 };
411 
412 /* at 0xfff6 */
413 #define SCP_ADDR	(0xfff6)
414 #define SCP_SIZE	(0x0a)
415 static scp_t  init_scp  = {
416 	SCP_SY_16BBUS,
417 	{ 0, 0 },
418 	ISCP_ADDR,
419 	0
420 };
421 
422 #define RFD_SIZE	(0x16)
423 static rfd_t  init_rfd	= {
424 	0,
425 	0,
426 	0,
427 	0,
428 	{ 0, },
429 	{ 0, },
430 	0
431 };
432 
433 #define RBD_SIZE	(0x0a)
434 static rbd_t  init_rbd	= {
435 	0,
436 	0,
437 	0,
438 	0,
439 	ETH_FRAME_LEN + 8
440 };
441 
442 #define TX_SIZE		(0x08)
443 #define TBD_SIZE	(0x08)
444 
445 static int
446 ether1_init_for_open (struct net_device *dev)
447 {
448 	int i, status, addr, next, next2;
449 	int failures = 0;
450 	unsigned long timeout;
451 
452 	writeb(CTRL_RST|CTRL_ACK, REG_CONTROL);
453 
454 	for (i = 0; i < 6; i++)
455 		init_sa.sa_addr[i] = dev->dev_addr[i];
456 
457 	/* load data structures into ether1 RAM */
458 	ether1_writebuffer (dev, &init_scp,  SCP_ADDR,  SCP_SIZE);
459 	ether1_writebuffer (dev, &init_iscp, ISCP_ADDR, ISCP_SIZE);
460 	ether1_writebuffer (dev, &init_scb,  SCB_ADDR,  SCB_SIZE);
461 	ether1_writebuffer (dev, &init_cfg,  CFG_ADDR,  CFG_SIZE);
462 	ether1_writebuffer (dev, &init_sa,   SA_ADDR,   SA_SIZE);
463 	ether1_writebuffer (dev, &init_mc,   MC_ADDR,   MC_SIZE);
464 	ether1_writebuffer (dev, &init_tdr,  TDR_ADDR,  TDR_SIZE);
465 	ether1_writebuffer (dev, &init_nop,  NOP_ADDR,  NOP_SIZE);
466 
467 	if (ether1_readw(dev, CFG_ADDR, cfg_t, cfg_command, NORMALIRQS) != CMD_CONFIG) {
468 		printk (KERN_ERR "%s: detected either RAM fault or compiler bug\n",
469 			dev->name);
470 		return 1;
471 	}
472 
473 	/*
474 	 * setup circularly linked list of { rfd, rbd, buffer }, with
475 	 * all rfds circularly linked, rbds circularly linked.
476 	 * First rfd is linked to scp, first rbd is linked to first
477 	 * rfd.  Last rbd has a suspend command.
478 	 */
479 	addr = RX_AREA_START;
480 	do {
481 		next = addr + RFD_SIZE + RBD_SIZE + ETH_FRAME_LEN + 10;
482 		next2 = next + RFD_SIZE + RBD_SIZE + ETH_FRAME_LEN + 10;
483 
484 		if (next2 >= RX_AREA_END) {
485 			next = RX_AREA_START;
486 			init_rfd.rfd_command = RFD_CMDEL | RFD_CMDSUSPEND;
487 			priv(dev)->rx_tail = addr;
488 		} else
489 			init_rfd.rfd_command = 0;
490 		if (addr == RX_AREA_START)
491 			init_rfd.rfd_rbdoffset = addr + RFD_SIZE;
492 		else
493 			init_rfd.rfd_rbdoffset = 0;
494 		init_rfd.rfd_link = next;
495 		init_rbd.rbd_link = next + RFD_SIZE;
496 		init_rbd.rbd_bufl = addr + RFD_SIZE + RBD_SIZE;
497 
498 		ether1_writebuffer (dev, &init_rfd, addr, RFD_SIZE);
499 		ether1_writebuffer (dev, &init_rbd, addr + RFD_SIZE, RBD_SIZE);
500 		addr = next;
501 	} while (next2 < RX_AREA_END);
502 
503 	priv(dev)->tx_link = NOP_ADDR;
504 	priv(dev)->tx_head = NOP_ADDR + NOP_SIZE;
505 	priv(dev)->tx_tail = TDR_ADDR;
506 	priv(dev)->rx_head = RX_AREA_START;
507 
508 	/* release reset & give 586 a prod */
509 	priv(dev)->resetting = 1;
510 	priv(dev)->initialising = 1;
511 	writeb(CTRL_RST, REG_CONTROL);
512 	writeb(0, REG_CONTROL);
513 	writeb(CTRL_CA, REG_CONTROL);
514 
515 	/* 586 should now unset iscp.busy */
516 	timeout = jiffies + HZ/2;
517 	while (ether1_readw(dev, ISCP_ADDR, iscp_t, iscp_busy, DISABLEIRQS) == 1) {
518 		if (time_after(jiffies, timeout)) {
519 			printk (KERN_WARNING "%s: can't initialise 82586: iscp is busy\n", dev->name);
520 			return 1;
521 		}
522 	}
523 
524 	/* check status of commands that we issued */
525 	timeout += HZ/10;
526 	while (((status = ether1_readw(dev, CFG_ADDR, cfg_t, cfg_status, DISABLEIRQS))
527 			& STAT_COMPLETE) == 0) {
528 		if (time_after(jiffies, timeout))
529 			break;
530 	}
531 
532 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
533 		printk (KERN_WARNING "%s: can't initialise 82586: config status %04X\n", dev->name, status);
534 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
535 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
536 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
537 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
538 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
539 		failures += 1;
540 	}
541 
542 	timeout += HZ/10;
543 	while (((status = ether1_readw(dev, SA_ADDR, sa_t, sa_status, DISABLEIRQS))
544 			& STAT_COMPLETE) == 0) {
545 		if (time_after(jiffies, timeout))
546 			break;
547 	}
548 
549 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
550 		printk (KERN_WARNING "%s: can't initialise 82586: set address status %04X\n", dev->name, status);
551 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
552 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
553 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
554 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
555 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
556 		failures += 1;
557 	}
558 
559 	timeout += HZ/10;
560 	while (((status = ether1_readw(dev, MC_ADDR, mc_t, mc_status, DISABLEIRQS))
561 			& STAT_COMPLETE) == 0) {
562 		if (time_after(jiffies, timeout))
563 			break;
564 	}
565 
566 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
567 		printk (KERN_WARNING "%s: can't initialise 82586: set multicast status %04X\n", dev->name, status);
568 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
569 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
570 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
571 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
572 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
573 		failures += 1;
574 	}
575 
576 	timeout += HZ;
577 	while (((status = ether1_readw(dev, TDR_ADDR, tdr_t, tdr_status, DISABLEIRQS))
578 			& STAT_COMPLETE) == 0) {
579 		if (time_after(jiffies, timeout))
580 			break;
581 	}
582 
583 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
584 		printk (KERN_WARNING "%s: can't tdr (ignored)\n", dev->name);
585 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
586 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
587 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
588 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
589 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
590 	} else {
591 		status = ether1_readw(dev, TDR_ADDR, tdr_t, tdr_result, DISABLEIRQS);
592 		if (status & TDR_XCVRPROB)
593 			printk (KERN_WARNING "%s: i/f failed tdr: transceiver problem\n", dev->name);
594 		else if ((status & (TDR_SHORT|TDR_OPEN)) && (status & TDR_TIME)) {
595 #ifdef FANCY
596 			printk (KERN_WARNING "%s: i/f failed tdr: cable %s %d.%d us away\n", dev->name,
597 				status & TDR_SHORT ? "short" : "open", (status & TDR_TIME) / 10,
598 				(status & TDR_TIME) % 10);
599 #else
600 			printk (KERN_WARNING "%s: i/f failed tdr: cable %s %d clks away\n", dev->name,
601 				status & TDR_SHORT ? "short" : "open", (status & TDR_TIME));
602 #endif
603 		}
604 	}
605 
606 	if (failures)
607 		ether1_reset (dev);
608 	return failures ? 1 : 0;
609 }
610 
611 /* ------------------------------------------------------------------------- */
612 
613 static int
614 ether1_txalloc (struct net_device *dev, int size)
615 {
616 	int start, tail;
617 
618 	size = (size + 1) & ~1;
619 	tail = priv(dev)->tx_tail;
620 
621 	if (priv(dev)->tx_head + size > TX_AREA_END) {
622 		if (tail > priv(dev)->tx_head)
623 			return -1;
624 		start = TX_AREA_START;
625 		if (start + size > tail)
626 			return -1;
627 		priv(dev)->tx_head = start + size;
628 	} else {
629 		if (priv(dev)->tx_head < tail && (priv(dev)->tx_head + size) > tail)
630 			return -1;
631 		start = priv(dev)->tx_head;
632 		priv(dev)->tx_head += size;
633 	}
634 
635 	return start;
636 }
637 
638 static int
639 ether1_open (struct net_device *dev)
640 {
641 	if (request_irq(dev->irq, ether1_interrupt, 0, "ether1", dev))
642 		return -EAGAIN;
643 
644 	if (ether1_init_for_open (dev)) {
645 		free_irq (dev->irq, dev);
646 		return -EAGAIN;
647 	}
648 
649 	netif_start_queue(dev);
650 
651 	return 0;
652 }
653 
654 static void
655 ether1_timeout(struct net_device *dev)
656 {
657 	printk(KERN_WARNING "%s: transmit timeout, network cable problem?\n",
658 		dev->name);
659 	printk(KERN_WARNING "%s: resetting device\n", dev->name);
660 
661 	ether1_reset (dev);
662 
663 	if (ether1_init_for_open (dev))
664 		printk (KERN_ERR "%s: unable to restart interface\n", dev->name);
665 
666 	dev->stats.tx_errors++;
667 	netif_wake_queue(dev);
668 }
669 
670 static int
671 ether1_sendpacket (struct sk_buff *skb, struct net_device *dev)
672 {
673 	int tmp, tst, nopaddr, txaddr, tbdaddr, dataddr;
674 	unsigned long flags;
675 	tx_t tx;
676 	tbd_t tbd;
677 	nop_t nop;
678 
679 	if (priv(dev)->restart) {
680 		printk(KERN_WARNING "%s: resetting device\n", dev->name);
681 
682 		ether1_reset(dev);
683 
684 		if (ether1_init_for_open(dev))
685 			printk(KERN_ERR "%s: unable to restart interface\n", dev->name);
686 		else
687 			priv(dev)->restart = 0;
688 	}
689 
690 	if (skb->len < ETH_ZLEN) {
691 		if (skb_padto(skb, ETH_ZLEN))
692 			goto out;
693 	}
694 
695 	/*
696 	 * insert packet followed by a nop
697 	 */
698 	txaddr = ether1_txalloc (dev, TX_SIZE);
699 	tbdaddr = ether1_txalloc (dev, TBD_SIZE);
700 	dataddr = ether1_txalloc (dev, skb->len);
701 	nopaddr = ether1_txalloc (dev, NOP_SIZE);
702 
703 	tx.tx_status = 0;
704 	tx.tx_command = CMD_TX | CMD_INTR;
705 	tx.tx_link = nopaddr;
706 	tx.tx_tbdoffset = tbdaddr;
707 	tbd.tbd_opts = TBD_EOL | skb->len;
708 	tbd.tbd_link = I82586_NULL;
709 	tbd.tbd_bufl = dataddr;
710 	tbd.tbd_bufh = 0;
711 	nop.nop_status = 0;
712 	nop.nop_command = CMD_NOP;
713 	nop.nop_link = nopaddr;
714 
715 	local_irq_save(flags);
716 	ether1_writebuffer (dev, &tx, txaddr, TX_SIZE);
717 	ether1_writebuffer (dev, &tbd, tbdaddr, TBD_SIZE);
718 	ether1_writebuffer (dev, skb->data, dataddr, skb->len);
719 	ether1_writebuffer (dev, &nop, nopaddr, NOP_SIZE);
720 	tmp = priv(dev)->tx_link;
721 	priv(dev)->tx_link = nopaddr;
722 
723 	/* now reset the previous nop pointer */
724 	ether1_writew(dev, txaddr, tmp, nop_t, nop_link, NORMALIRQS);
725 
726 	local_irq_restore(flags);
727 
728 	/* handle transmit */
729 
730 	/* check to see if we have room for a full sized ether frame */
731 	tmp = priv(dev)->tx_head;
732 	tst = ether1_txalloc (dev, TX_SIZE + TBD_SIZE + NOP_SIZE + ETH_FRAME_LEN);
733 	priv(dev)->tx_head = tmp;
734 	dev_kfree_skb (skb);
735 
736 	if (tst == -1)
737 		netif_stop_queue(dev);
738 
739  out:
740 	return NETDEV_TX_OK;
741 }
742 
743 static void
744 ether1_xmit_done (struct net_device *dev)
745 {
746 	nop_t nop;
747 	int caddr, tst;
748 
749 	caddr = priv(dev)->tx_tail;
750 
751 again:
752 	ether1_readbuffer (dev, &nop, caddr, NOP_SIZE);
753 
754 	switch (nop.nop_command & CMD_MASK) {
755 	case CMD_TDR:
756 		/* special case */
757 		if (ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS)
758 				!= (unsigned short)I82586_NULL) {
759 			ether1_writew(dev, SCB_CMDCUCSTART | SCB_CMDRXSTART, SCB_ADDR, scb_t,
760 				    scb_command, NORMALIRQS);
761 			writeb(CTRL_CA, REG_CONTROL);
762 		}
763 		priv(dev)->tx_tail = NOP_ADDR;
764 		return;
765 
766 	case CMD_NOP:
767 		if (nop.nop_link == caddr) {
768 			if (priv(dev)->initialising == 0)
769 				printk (KERN_WARNING "%s: strange command complete with no tx command!\n", dev->name);
770 			else
771 			        priv(dev)->initialising = 0;
772 			return;
773 		}
774 		if (caddr == nop.nop_link)
775 			return;
776 		caddr = nop.nop_link;
777 		goto again;
778 
779 	case CMD_TX:
780 		if (nop.nop_status & STAT_COMPLETE)
781 			break;
782 		printk (KERN_ERR "%s: strange command complete without completed command\n", dev->name);
783 		priv(dev)->restart = 1;
784 		return;
785 
786 	default:
787 		printk (KERN_WARNING "%s: strange command %d complete! (offset %04X)", dev->name,
788 			nop.nop_command & CMD_MASK, caddr);
789 		priv(dev)->restart = 1;
790 		return;
791 	}
792 
793 	while (nop.nop_status & STAT_COMPLETE) {
794 		if (nop.nop_status & STAT_OK) {
795 			dev->stats.tx_packets++;
796 			dev->stats.collisions += (nop.nop_status & STAT_COLLISIONS);
797 		} else {
798 			dev->stats.tx_errors++;
799 
800 			if (nop.nop_status & STAT_COLLAFTERTX)
801 				dev->stats.collisions++;
802 			if (nop.nop_status & STAT_NOCARRIER)
803 				dev->stats.tx_carrier_errors++;
804 			if (nop.nop_status & STAT_TXLOSTCTS)
805 				printk (KERN_WARNING "%s: cts lost\n", dev->name);
806 			if (nop.nop_status & STAT_TXSLOWDMA)
807 				dev->stats.tx_fifo_errors++;
808 			if (nop.nop_status & STAT_COLLEXCESSIVE)
809 				dev->stats.collisions += 16;
810 		}
811 
812 		if (nop.nop_link == caddr) {
813 			printk (KERN_ERR "%s: tx buffer chaining error: tx command points to itself\n", dev->name);
814 			break;
815 		}
816 
817 		caddr = nop.nop_link;
818 		ether1_readbuffer (dev, &nop, caddr, NOP_SIZE);
819 		if ((nop.nop_command & CMD_MASK) != CMD_NOP) {
820 			printk (KERN_ERR "%s: tx buffer chaining error: no nop after tx command\n", dev->name);
821 			break;
822 		}
823 
824 		if (caddr == nop.nop_link)
825 			break;
826 
827 		caddr = nop.nop_link;
828 		ether1_readbuffer (dev, &nop, caddr, NOP_SIZE);
829 		if ((nop.nop_command & CMD_MASK) != CMD_TX) {
830 			printk (KERN_ERR "%s: tx buffer chaining error: no tx command after nop\n", dev->name);
831 			break;
832 		}
833 	}
834 	priv(dev)->tx_tail = caddr;
835 
836 	caddr = priv(dev)->tx_head;
837 	tst = ether1_txalloc (dev, TX_SIZE + TBD_SIZE + NOP_SIZE + ETH_FRAME_LEN);
838 	priv(dev)->tx_head = caddr;
839 	if (tst != -1)
840 		netif_wake_queue(dev);
841 }
842 
843 static void
844 ether1_recv_done (struct net_device *dev)
845 {
846 	int status;
847 	int nexttail, rbdaddr;
848 	rbd_t rbd;
849 
850 	do {
851 		status = ether1_readw(dev, priv(dev)->rx_head, rfd_t, rfd_status, NORMALIRQS);
852 		if ((status & RFD_COMPLETE) == 0)
853 			break;
854 
855 		rbdaddr = ether1_readw(dev, priv(dev)->rx_head, rfd_t, rfd_rbdoffset, NORMALIRQS);
856 		ether1_readbuffer (dev, &rbd, rbdaddr, RBD_SIZE);
857 
858 		if ((rbd.rbd_status & (RBD_EOF | RBD_ACNTVALID)) == (RBD_EOF | RBD_ACNTVALID)) {
859 			int length = rbd.rbd_status & RBD_ACNT;
860 			struct sk_buff *skb;
861 
862 			length = (length + 1) & ~1;
863 			skb = netdev_alloc_skb(dev, length + 2);
864 
865 			if (skb) {
866 				skb_reserve (skb, 2);
867 
868 				ether1_readbuffer (dev, skb_put (skb, length), rbd.rbd_bufl, length);
869 
870 				skb->protocol = eth_type_trans (skb, dev);
871 				netif_rx (skb);
872 				dev->stats.rx_packets++;
873 			} else
874 				dev->stats.rx_dropped++;
875 		} else {
876 			printk(KERN_WARNING "%s: %s\n", dev->name,
877 				(rbd.rbd_status & RBD_EOF) ? "oversized packet" : "acnt not valid");
878 			dev->stats.rx_dropped++;
879 		}
880 
881 		nexttail = ether1_readw(dev, priv(dev)->rx_tail, rfd_t, rfd_link, NORMALIRQS);
882 		/* nexttail should be rx_head */
883 		if (nexttail != priv(dev)->rx_head)
884 			printk(KERN_ERR "%s: receiver buffer chaining error (%04X != %04X)\n",
885 				dev->name, nexttail, priv(dev)->rx_head);
886 		ether1_writew(dev, RFD_CMDEL | RFD_CMDSUSPEND, nexttail, rfd_t, rfd_command, NORMALIRQS);
887 		ether1_writew(dev, 0, priv(dev)->rx_tail, rfd_t, rfd_command, NORMALIRQS);
888 		ether1_writew(dev, 0, priv(dev)->rx_tail, rfd_t, rfd_status, NORMALIRQS);
889 		ether1_writew(dev, 0, priv(dev)->rx_tail, rfd_t, rfd_rbdoffset, NORMALIRQS);
890 
891 		priv(dev)->rx_tail = nexttail;
892 		priv(dev)->rx_head = ether1_readw(dev, priv(dev)->rx_head, rfd_t, rfd_link, NORMALIRQS);
893 	} while (1);
894 }
895 
896 static irqreturn_t
897 ether1_interrupt (int irq, void *dev_id)
898 {
899 	struct net_device *dev = (struct net_device *)dev_id;
900 	int status;
901 
902 	status = ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS);
903 
904 	if (status) {
905 		ether1_writew(dev, status & (SCB_STRNR | SCB_STCNA | SCB_STFR | SCB_STCX),
906 			    SCB_ADDR, scb_t, scb_command, NORMALIRQS);
907 		writeb(CTRL_CA | CTRL_ACK, REG_CONTROL);
908 		if (status & SCB_STCX) {
909 			ether1_xmit_done (dev);
910 		}
911 		if (status & SCB_STCNA) {
912 			if (priv(dev)->resetting == 0)
913 				printk (KERN_WARNING "%s: CU went not ready ???\n", dev->name);
914 			else
915 				priv(dev)->resetting += 1;
916 			if (ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS)
917 					!= (unsigned short)I82586_NULL) {
918 				ether1_writew(dev, SCB_CMDCUCSTART, SCB_ADDR, scb_t, scb_command, NORMALIRQS);
919 				writeb(CTRL_CA, REG_CONTROL);
920 			}
921 			if (priv(dev)->resetting == 2)
922 				priv(dev)->resetting = 0;
923 		}
924 		if (status & SCB_STFR) {
925 			ether1_recv_done (dev);
926 		}
927 		if (status & SCB_STRNR) {
928 			if (ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS) & SCB_STRXSUSP) {
929 				printk (KERN_WARNING "%s: RU went not ready: RU suspended\n", dev->name);
930 				ether1_writew(dev, SCB_CMDRXRESUME, SCB_ADDR, scb_t, scb_command, NORMALIRQS);
931 				writeb(CTRL_CA, REG_CONTROL);
932 				dev->stats.rx_dropped++;	/* we suspended due to lack of buffer space */
933 			} else
934 				printk(KERN_WARNING "%s: RU went not ready: %04X\n", dev->name,
935 					ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS));
936 			printk (KERN_WARNING "RU ptr = %04X\n", ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset,
937 						NORMALIRQS));
938 		}
939 	} else
940 		writeb(CTRL_ACK, REG_CONTROL);
941 
942 	return IRQ_HANDLED;
943 }
944 
945 static int
946 ether1_close (struct net_device *dev)
947 {
948 	ether1_reset (dev);
949 
950 	free_irq(dev->irq, dev);
951 
952 	return 0;
953 }
954 
955 /*
956  * Set or clear the multicast filter for this adaptor.
957  * num_addrs == -1	Promiscuous mode, receive all packets.
958  * num_addrs == 0	Normal mode, clear multicast list.
959  * num_addrs > 0	Multicast mode, receive normal and MC packets, and do
960  *			best-effort filtering.
961  */
962 static void
963 ether1_setmulticastlist (struct net_device *dev)
964 {
965 }
966 
967 /* ------------------------------------------------------------------------- */
968 
969 static void ether1_banner(void)
970 {
971 	static unsigned int version_printed = 0;
972 
973 	if (net_debug && version_printed++ == 0)
974 		printk(KERN_INFO "%s", version);
975 }
976 
977 static const struct net_device_ops ether1_netdev_ops = {
978 	.ndo_open		= ether1_open,
979 	.ndo_stop		= ether1_close,
980 	.ndo_start_xmit		= ether1_sendpacket,
981 	.ndo_set_rx_mode	= ether1_setmulticastlist,
982 	.ndo_tx_timeout		= ether1_timeout,
983 	.ndo_validate_addr	= eth_validate_addr,
984 	.ndo_set_mac_address	= eth_mac_addr,
985 };
986 
987 static int
988 ether1_probe(struct expansion_card *ec, const struct ecard_id *id)
989 {
990 	struct net_device *dev;
991 	int i, ret = 0;
992 
993 	ether1_banner();
994 
995 	ret = ecard_request_resources(ec);
996 	if (ret)
997 		goto out;
998 
999 	dev = alloc_etherdev(sizeof(struct ether1_priv));
1000 	if (!dev) {
1001 		ret = -ENOMEM;
1002 		goto release;
1003 	}
1004 
1005 	SET_NETDEV_DEV(dev, &ec->dev);
1006 
1007 	dev->irq = ec->irq;
1008 	priv(dev)->base = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
1009 	if (!priv(dev)->base) {
1010 		ret = -ENOMEM;
1011 		goto free;
1012 	}
1013 
1014 	if ((priv(dev)->bus_type = ether1_reset(dev)) == 0) {
1015 		ret = -ENODEV;
1016 		goto free;
1017 	}
1018 
1019 	for (i = 0; i < 6; i++)
1020 		dev->dev_addr[i] = readb(IDPROM_ADDRESS + (i << 2));
1021 
1022 	if (ether1_init_2(dev)) {
1023 		ret = -ENODEV;
1024 		goto free;
1025 	}
1026 
1027 	dev->netdev_ops		= &ether1_netdev_ops;
1028 	dev->watchdog_timeo	= 5 * HZ / 100;
1029 
1030 	ret = register_netdev(dev);
1031 	if (ret)
1032 		goto free;
1033 
1034 	printk(KERN_INFO "%s: ether1 in slot %d, %pM\n",
1035 		dev->name, ec->slot_no, dev->dev_addr);
1036 
1037 	ecard_set_drvdata(ec, dev);
1038 	return 0;
1039 
1040  free:
1041 	free_netdev(dev);
1042  release:
1043 	ecard_release_resources(ec);
1044  out:
1045 	return ret;
1046 }
1047 
1048 static void ether1_remove(struct expansion_card *ec)
1049 {
1050 	struct net_device *dev = ecard_get_drvdata(ec);
1051 
1052 	ecard_set_drvdata(ec, NULL);
1053 
1054 	unregister_netdev(dev);
1055 	free_netdev(dev);
1056 	ecard_release_resources(ec);
1057 }
1058 
1059 static const struct ecard_id ether1_ids[] = {
1060 	{ MANU_ACORN, PROD_ACORN_ETHER1 },
1061 	{ 0xffff, 0xffff }
1062 };
1063 
1064 static struct ecard_driver ether1_driver = {
1065 	.probe		= ether1_probe,
1066 	.remove		= ether1_remove,
1067 	.id_table	= ether1_ids,
1068 	.drv = {
1069 		.name	= "ether1",
1070 	},
1071 };
1072 
1073 static int __init ether1_init(void)
1074 {
1075 	return ecard_register_driver(&ether1_driver);
1076 }
1077 
1078 static void __exit ether1_exit(void)
1079 {
1080 	ecard_remove_driver(&ether1_driver);
1081 }
1082 
1083 module_init(ether1_init);
1084 module_exit(ether1_exit);
1085 
1086 MODULE_LICENSE("GPL");
1087