1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/drivers/acorn/net/ether1.c
4  *
5  *  Copyright (C) 1996-2000 Russell King
6  *
7  *  Acorn ether1 driver (82586 chip) for Acorn machines
8  *
9  * We basically keep two queues in the cards memory - one for transmit
10  * and one for receive.  Each has a head and a tail.  The head is where
11  * we/the chip adds packets to be transmitted/received, and the tail
12  * is where the transmitter has got to/where the receiver will stop.
13  * Both of these queues are circular, and since the chip is running
14  * all the time, we have to be careful when we modify the pointers etc
15  * so that the buffer memory contents is valid all the time.
16  *
17  * Change log:
18  * 1.00	RMK			Released
19  * 1.01	RMK	19/03/1996	Transfers the last odd byte onto/off of the card now.
20  * 1.02	RMK	25/05/1997	Added code to restart RU if it goes not ready
21  * 1.03	RMK	14/09/1997	Cleaned up the handling of a reset during the TX interrupt.
22  *				Should prevent lockup.
23  * 1.04 RMK	17/09/1997	Added more info when initialsation of chip goes wrong.
24  *				TDR now only reports failure when chip reports non-zero
25  *				TDR time-distance.
26  * 1.05	RMK	31/12/1997	Removed calls to dev_tint for 2.1
27  * 1.06	RMK	10/02/2000	Updated for 2.3.43
28  * 1.07	RMK	13/05/2000	Updated for 2.3.99-pre8
29  */
30 
31 #include <linux/module.h>
32 #include <linux/kernel.h>
33 #include <linux/types.h>
34 #include <linux/fcntl.h>
35 #include <linux/interrupt.h>
36 #include <linux/ioport.h>
37 #include <linux/in.h>
38 #include <linux/slab.h>
39 #include <linux/string.h>
40 #include <linux/errno.h>
41 #include <linux/device.h>
42 #include <linux/init.h>
43 #include <linux/netdevice.h>
44 #include <linux/etherdevice.h>
45 #include <linux/skbuff.h>
46 #include <linux/bitops.h>
47 
48 #include <asm/io.h>
49 #include <asm/dma.h>
50 #include <asm/ecard.h>
51 
52 #define __ETHER1_C
53 #include "ether1.h"
54 
55 static unsigned int net_debug = NET_DEBUG;
56 
57 #define BUFFER_SIZE	0x10000
58 #define TX_AREA_START	0x00100
59 #define TX_AREA_END	0x05000
60 #define RX_AREA_START	0x05000
61 #define RX_AREA_END	0x0fc00
62 
63 static int ether1_open(struct net_device *dev);
64 static netdev_tx_t ether1_sendpacket(struct sk_buff *skb,
65 				     struct net_device *dev);
66 static irqreturn_t ether1_interrupt(int irq, void *dev_id);
67 static int ether1_close(struct net_device *dev);
68 static void ether1_setmulticastlist(struct net_device *dev);
69 static void ether1_timeout(struct net_device *dev);
70 
71 /* ------------------------------------------------------------------------- */
72 
73 static char version[] = "ether1 ethernet driver (c) 2000 Russell King v1.07\n";
74 
75 #define BUS_16 16
76 #define BUS_8  8
77 
78 /* ------------------------------------------------------------------------- */
79 
80 #define DISABLEIRQS 1
81 #define NORMALIRQS  0
82 
83 #define ether1_readw(dev, addr, type, offset, svflgs) ether1_inw_p (dev, addr + (int)(&((type *)0)->offset), svflgs)
84 #define ether1_writew(dev, val, addr, type, offset, svflgs) ether1_outw_p (dev, val, addr + (int)(&((type *)0)->offset), svflgs)
85 
86 static inline unsigned short
87 ether1_inw_p (struct net_device *dev, int addr, int svflgs)
88 {
89 	unsigned long flags;
90 	unsigned short ret;
91 
92 	if (svflgs)
93 		local_irq_save (flags);
94 
95 	writeb(addr >> 12, REG_PAGE);
96 	ret = readw(ETHER1_RAM + ((addr & 4095) << 1));
97 	if (svflgs)
98 		local_irq_restore (flags);
99 	return ret;
100 }
101 
102 static inline void
103 ether1_outw_p (struct net_device *dev, unsigned short val, int addr, int svflgs)
104 {
105 	unsigned long flags;
106 
107 	if (svflgs)
108 		local_irq_save (flags);
109 
110 	writeb(addr >> 12, REG_PAGE);
111 	writew(val, ETHER1_RAM + ((addr & 4095) << 1));
112 	if (svflgs)
113 		local_irq_restore (flags);
114 }
115 
116 /*
117  * Some inline assembler to allow fast transfers on to/off of the card.
118  * Since this driver depends on some features presented by the ARM
119  * specific architecture, and that you can't configure this driver
120  * without specifiing ARM mode, this is not a problem.
121  *
122  * This routine is essentially an optimised memcpy from the card's
123  * onboard RAM to kernel memory.
124  */
125 static void
126 ether1_writebuffer (struct net_device *dev, void *data, unsigned int start, unsigned int length)
127 {
128 	unsigned int page, thislen, offset;
129 	void __iomem *addr;
130 
131 	offset = start & 4095;
132 	page = start >> 12;
133 	addr = ETHER1_RAM + (offset << 1);
134 
135 	if (offset + length > 4096)
136 		thislen = 4096 - offset;
137 	else
138 		thislen = length;
139 
140 	do {
141 		int used;
142 
143 		writeb(page, REG_PAGE);
144 		length -= thislen;
145 
146 		__asm__ __volatile__(
147 	"subs	%3, %3, #2\n\
148 	bmi	2f\n\
149 1:	ldr	%0, [%1], #2\n\
150 	mov	%0, %0, lsl #16\n\
151 	orr	%0, %0, %0, lsr #16\n\
152 	str	%0, [%2], #4\n\
153 	subs	%3, %3, #2\n\
154 	bmi	2f\n\
155 	ldr	%0, [%1], #2\n\
156 	mov	%0, %0, lsl #16\n\
157 	orr	%0, %0, %0, lsr #16\n\
158 	str	%0, [%2], #4\n\
159 	subs	%3, %3, #2\n\
160 	bmi	2f\n\
161 	ldr	%0, [%1], #2\n\
162 	mov	%0, %0, lsl #16\n\
163 	orr	%0, %0, %0, lsr #16\n\
164 	str	%0, [%2], #4\n\
165 	subs	%3, %3, #2\n\
166 	bmi	2f\n\
167 	ldr	%0, [%1], #2\n\
168 	mov	%0, %0, lsl #16\n\
169 	orr	%0, %0, %0, lsr #16\n\
170 	str	%0, [%2], #4\n\
171 	subs	%3, %3, #2\n\
172 	bpl	1b\n\
173 2:	adds	%3, %3, #1\n\
174 	ldreqb	%0, [%1]\n\
175 	streqb	%0, [%2]"
176 		: "=&r" (used), "=&r" (data)
177 		: "r"  (addr), "r" (thislen), "1" (data));
178 
179 		addr = ETHER1_RAM;
180 
181 		thislen = length;
182 		if (thislen > 4096)
183 			thislen = 4096;
184 		page++;
185 	} while (thislen);
186 }
187 
188 static void
189 ether1_readbuffer (struct net_device *dev, void *data, unsigned int start, unsigned int length)
190 {
191 	unsigned int page, thislen, offset;
192 	void __iomem *addr;
193 
194 	offset = start & 4095;
195 	page = start >> 12;
196 	addr = ETHER1_RAM + (offset << 1);
197 
198 	if (offset + length > 4096)
199 		thislen = 4096 - offset;
200 	else
201 		thislen = length;
202 
203 	do {
204 		int used;
205 
206 		writeb(page, REG_PAGE);
207 		length -= thislen;
208 
209 		__asm__ __volatile__(
210 	"subs	%3, %3, #2\n\
211 	bmi	2f\n\
212 1:	ldr	%0, [%2], #4\n\
213 	strb	%0, [%1], #1\n\
214 	mov	%0, %0, lsr #8\n\
215 	strb	%0, [%1], #1\n\
216 	subs	%3, %3, #2\n\
217 	bmi	2f\n\
218 	ldr	%0, [%2], #4\n\
219 	strb	%0, [%1], #1\n\
220 	mov	%0, %0, lsr #8\n\
221 	strb	%0, [%1], #1\n\
222 	subs	%3, %3, #2\n\
223 	bmi	2f\n\
224 	ldr	%0, [%2], #4\n\
225 	strb	%0, [%1], #1\n\
226 	mov	%0, %0, lsr #8\n\
227 	strb	%0, [%1], #1\n\
228 	subs	%3, %3, #2\n\
229 	bmi	2f\n\
230 	ldr	%0, [%2], #4\n\
231 	strb	%0, [%1], #1\n\
232 	mov	%0, %0, lsr #8\n\
233 	strb	%0, [%1], #1\n\
234 	subs	%3, %3, #2\n\
235 	bpl	1b\n\
236 2:	adds	%3, %3, #1\n\
237 	ldreqb	%0, [%2]\n\
238 	streqb	%0, [%1]"
239 		: "=&r" (used), "=&r" (data)
240 		: "r"  (addr), "r" (thislen), "1" (data));
241 
242 		addr = ETHER1_RAM;
243 
244 		thislen = length;
245 		if (thislen > 4096)
246 			thislen = 4096;
247 		page++;
248 	} while (thislen);
249 }
250 
251 static int
252 ether1_ramtest(struct net_device *dev, unsigned char byte)
253 {
254 	unsigned char *buffer = kmalloc (BUFFER_SIZE, GFP_KERNEL);
255 	int i, ret = BUFFER_SIZE;
256 	int max_errors = 15;
257 	int bad = -1;
258 	int bad_start = 0;
259 
260 	if (!buffer)
261 		return 1;
262 
263 	memset (buffer, byte, BUFFER_SIZE);
264 	ether1_writebuffer (dev, buffer, 0, BUFFER_SIZE);
265 	memset (buffer, byte ^ 0xff, BUFFER_SIZE);
266 	ether1_readbuffer (dev, buffer, 0, BUFFER_SIZE);
267 
268 	for (i = 0; i < BUFFER_SIZE; i++) {
269 		if (buffer[i] != byte) {
270 			if (max_errors >= 0 && bad != buffer[i]) {
271 				if (bad != -1)
272 					printk ("\n");
273 				printk (KERN_CRIT "%s: RAM failed with (%02X instead of %02X) at 0x%04X",
274 					dev->name, buffer[i], byte, i);
275 				ret = -ENODEV;
276 				max_errors --;
277 				bad = buffer[i];
278 				bad_start = i;
279 			}
280 		} else {
281 			if (bad != -1) {
282 			    	if (bad_start == i - 1)
283 					printk ("\n");
284 				else
285 					printk (" - 0x%04X\n", i - 1);
286 				bad = -1;
287 			}
288 		}
289 	}
290 
291 	if (bad != -1)
292 		printk (" - 0x%04X\n", BUFFER_SIZE);
293 	kfree (buffer);
294 
295 	return ret;
296 }
297 
298 static int
299 ether1_reset (struct net_device *dev)
300 {
301 	writeb(CTRL_RST|CTRL_ACK, REG_CONTROL);
302 	return BUS_16;
303 }
304 
305 static int
306 ether1_init_2(struct net_device *dev)
307 {
308 	int i;
309 	dev->mem_start = 0;
310 
311 	i = ether1_ramtest (dev, 0x5a);
312 
313 	if (i > 0)
314 		i = ether1_ramtest (dev, 0x1e);
315 
316 	if (i <= 0)
317 	    	return -ENODEV;
318 
319 	dev->mem_end = i;
320 	return 0;
321 }
322 
323 /*
324  * These are the structures that are loaded into the ether RAM card to
325  * initialise the 82586
326  */
327 
328 /* at 0x0100 */
329 #define NOP_ADDR	(TX_AREA_START)
330 #define NOP_SIZE	(0x06)
331 static nop_t  init_nop  = {
332 	0,
333 	CMD_NOP,
334 	NOP_ADDR
335 };
336 
337 /* at 0x003a */
338 #define TDR_ADDR	(0x003a)
339 #define TDR_SIZE	(0x08)
340 static tdr_t  init_tdr	= {
341 	0,
342 	CMD_TDR | CMD_INTR,
343 	NOP_ADDR,
344 	0
345 };
346 
347 /* at 0x002e */
348 #define MC_ADDR		(0x002e)
349 #define MC_SIZE		(0x0c)
350 static mc_t   init_mc   = {
351 	0,
352 	CMD_SETMULTICAST,
353 	TDR_ADDR,
354 	0,
355 	{ { 0, } }
356 };
357 
358 /* at 0x0022 */
359 #define SA_ADDR		(0x0022)
360 #define SA_SIZE		(0x0c)
361 static sa_t   init_sa   = {
362 	0,
363 	CMD_SETADDRESS,
364 	MC_ADDR,
365 	{ 0, }
366 };
367 
368 /* at 0x0010 */
369 #define CFG_ADDR	(0x0010)
370 #define CFG_SIZE	(0x12)
371 static cfg_t  init_cfg  = {
372 	0,
373 	CMD_CONFIG,
374 	SA_ADDR,
375 	8,
376 	8,
377 	CFG8_SRDY,
378 	CFG9_PREAMB8 | CFG9_ADDRLENBUF | CFG9_ADDRLEN(6),
379 	0,
380 	0x60,
381 	0,
382 	CFG13_RETRY(15) | CFG13_SLOTH(2),
383 	0,
384 };
385 
386 /* at 0x0000 */
387 #define SCB_ADDR	(0x0000)
388 #define SCB_SIZE	(0x10)
389 static scb_t  init_scb  = {
390 	0,
391 	SCB_CMDACKRNR | SCB_CMDACKCNA | SCB_CMDACKFR | SCB_CMDACKCX,
392 	CFG_ADDR,
393 	RX_AREA_START,
394 	0,
395 	0,
396 	0,
397 	0
398 };
399 
400 /* at 0xffee */
401 #define ISCP_ADDR	(0xffee)
402 #define ISCP_SIZE	(0x08)
403 static iscp_t init_iscp = {
404 	1,
405 	SCB_ADDR,
406 	0x0000,
407 	0x0000
408 };
409 
410 /* at 0xfff6 */
411 #define SCP_ADDR	(0xfff6)
412 #define SCP_SIZE	(0x0a)
413 static scp_t  init_scp  = {
414 	SCP_SY_16BBUS,
415 	{ 0, 0 },
416 	ISCP_ADDR,
417 	0
418 };
419 
420 #define RFD_SIZE	(0x16)
421 static rfd_t  init_rfd	= {
422 	0,
423 	0,
424 	0,
425 	0,
426 	{ 0, },
427 	{ 0, },
428 	0
429 };
430 
431 #define RBD_SIZE	(0x0a)
432 static rbd_t  init_rbd	= {
433 	0,
434 	0,
435 	0,
436 	0,
437 	ETH_FRAME_LEN + 8
438 };
439 
440 #define TX_SIZE		(0x08)
441 #define TBD_SIZE	(0x08)
442 
443 static int
444 ether1_init_for_open (struct net_device *dev)
445 {
446 	int i, status, addr, next, next2;
447 	int failures = 0;
448 	unsigned long timeout;
449 
450 	writeb(CTRL_RST|CTRL_ACK, REG_CONTROL);
451 
452 	for (i = 0; i < 6; i++)
453 		init_sa.sa_addr[i] = dev->dev_addr[i];
454 
455 	/* load data structures into ether1 RAM */
456 	ether1_writebuffer (dev, &init_scp,  SCP_ADDR,  SCP_SIZE);
457 	ether1_writebuffer (dev, &init_iscp, ISCP_ADDR, ISCP_SIZE);
458 	ether1_writebuffer (dev, &init_scb,  SCB_ADDR,  SCB_SIZE);
459 	ether1_writebuffer (dev, &init_cfg,  CFG_ADDR,  CFG_SIZE);
460 	ether1_writebuffer (dev, &init_sa,   SA_ADDR,   SA_SIZE);
461 	ether1_writebuffer (dev, &init_mc,   MC_ADDR,   MC_SIZE);
462 	ether1_writebuffer (dev, &init_tdr,  TDR_ADDR,  TDR_SIZE);
463 	ether1_writebuffer (dev, &init_nop,  NOP_ADDR,  NOP_SIZE);
464 
465 	if (ether1_readw(dev, CFG_ADDR, cfg_t, cfg_command, NORMALIRQS) != CMD_CONFIG) {
466 		printk (KERN_ERR "%s: detected either RAM fault or compiler bug\n",
467 			dev->name);
468 		return 1;
469 	}
470 
471 	/*
472 	 * setup circularly linked list of { rfd, rbd, buffer }, with
473 	 * all rfds circularly linked, rbds circularly linked.
474 	 * First rfd is linked to scp, first rbd is linked to first
475 	 * rfd.  Last rbd has a suspend command.
476 	 */
477 	addr = RX_AREA_START;
478 	do {
479 		next = addr + RFD_SIZE + RBD_SIZE + ETH_FRAME_LEN + 10;
480 		next2 = next + RFD_SIZE + RBD_SIZE + ETH_FRAME_LEN + 10;
481 
482 		if (next2 >= RX_AREA_END) {
483 			next = RX_AREA_START;
484 			init_rfd.rfd_command = RFD_CMDEL | RFD_CMDSUSPEND;
485 			priv(dev)->rx_tail = addr;
486 		} else
487 			init_rfd.rfd_command = 0;
488 		if (addr == RX_AREA_START)
489 			init_rfd.rfd_rbdoffset = addr + RFD_SIZE;
490 		else
491 			init_rfd.rfd_rbdoffset = 0;
492 		init_rfd.rfd_link = next;
493 		init_rbd.rbd_link = next + RFD_SIZE;
494 		init_rbd.rbd_bufl = addr + RFD_SIZE + RBD_SIZE;
495 
496 		ether1_writebuffer (dev, &init_rfd, addr, RFD_SIZE);
497 		ether1_writebuffer (dev, &init_rbd, addr + RFD_SIZE, RBD_SIZE);
498 		addr = next;
499 	} while (next2 < RX_AREA_END);
500 
501 	priv(dev)->tx_link = NOP_ADDR;
502 	priv(dev)->tx_head = NOP_ADDR + NOP_SIZE;
503 	priv(dev)->tx_tail = TDR_ADDR;
504 	priv(dev)->rx_head = RX_AREA_START;
505 
506 	/* release reset & give 586 a prod */
507 	priv(dev)->resetting = 1;
508 	priv(dev)->initialising = 1;
509 	writeb(CTRL_RST, REG_CONTROL);
510 	writeb(0, REG_CONTROL);
511 	writeb(CTRL_CA, REG_CONTROL);
512 
513 	/* 586 should now unset iscp.busy */
514 	timeout = jiffies + HZ/2;
515 	while (ether1_readw(dev, ISCP_ADDR, iscp_t, iscp_busy, DISABLEIRQS) == 1) {
516 		if (time_after(jiffies, timeout)) {
517 			printk (KERN_WARNING "%s: can't initialise 82586: iscp is busy\n", dev->name);
518 			return 1;
519 		}
520 	}
521 
522 	/* check status of commands that we issued */
523 	timeout += HZ/10;
524 	while (((status = ether1_readw(dev, CFG_ADDR, cfg_t, cfg_status, DISABLEIRQS))
525 			& STAT_COMPLETE) == 0) {
526 		if (time_after(jiffies, timeout))
527 			break;
528 	}
529 
530 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
531 		printk (KERN_WARNING "%s: can't initialise 82586: config status %04X\n", dev->name, status);
532 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
533 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
534 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
535 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
536 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
537 		failures += 1;
538 	}
539 
540 	timeout += HZ/10;
541 	while (((status = ether1_readw(dev, SA_ADDR, sa_t, sa_status, DISABLEIRQS))
542 			& STAT_COMPLETE) == 0) {
543 		if (time_after(jiffies, timeout))
544 			break;
545 	}
546 
547 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
548 		printk (KERN_WARNING "%s: can't initialise 82586: set address status %04X\n", dev->name, status);
549 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
550 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
551 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
552 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
553 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
554 		failures += 1;
555 	}
556 
557 	timeout += HZ/10;
558 	while (((status = ether1_readw(dev, MC_ADDR, mc_t, mc_status, DISABLEIRQS))
559 			& STAT_COMPLETE) == 0) {
560 		if (time_after(jiffies, timeout))
561 			break;
562 	}
563 
564 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
565 		printk (KERN_WARNING "%s: can't initialise 82586: set multicast status %04X\n", dev->name, status);
566 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
567 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
568 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
569 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
570 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
571 		failures += 1;
572 	}
573 
574 	timeout += HZ;
575 	while (((status = ether1_readw(dev, TDR_ADDR, tdr_t, tdr_status, DISABLEIRQS))
576 			& STAT_COMPLETE) == 0) {
577 		if (time_after(jiffies, timeout))
578 			break;
579 	}
580 
581 	if ((status & (STAT_COMPLETE | STAT_OK)) != (STAT_COMPLETE | STAT_OK)) {
582 		printk (KERN_WARNING "%s: can't tdr (ignored)\n", dev->name);
583 		printk (KERN_DEBUG "%s: SCB=[STS=%04X CMD=%04X CBL=%04X RFA=%04X]\n", dev->name,
584 			ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS),
585 			ether1_readw(dev, SCB_ADDR, scb_t, scb_command, NORMALIRQS),
586 			ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS),
587 			ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset, NORMALIRQS));
588 	} else {
589 		status = ether1_readw(dev, TDR_ADDR, tdr_t, tdr_result, DISABLEIRQS);
590 		if (status & TDR_XCVRPROB)
591 			printk (KERN_WARNING "%s: i/f failed tdr: transceiver problem\n", dev->name);
592 		else if ((status & (TDR_SHORT|TDR_OPEN)) && (status & TDR_TIME)) {
593 #ifdef FANCY
594 			printk (KERN_WARNING "%s: i/f failed tdr: cable %s %d.%d us away\n", dev->name,
595 				status & TDR_SHORT ? "short" : "open", (status & TDR_TIME) / 10,
596 				(status & TDR_TIME) % 10);
597 #else
598 			printk (KERN_WARNING "%s: i/f failed tdr: cable %s %d clks away\n", dev->name,
599 				status & TDR_SHORT ? "short" : "open", (status & TDR_TIME));
600 #endif
601 		}
602 	}
603 
604 	if (failures)
605 		ether1_reset (dev);
606 	return failures ? 1 : 0;
607 }
608 
609 /* ------------------------------------------------------------------------- */
610 
611 static int
612 ether1_txalloc (struct net_device *dev, int size)
613 {
614 	int start, tail;
615 
616 	size = (size + 1) & ~1;
617 	tail = priv(dev)->tx_tail;
618 
619 	if (priv(dev)->tx_head + size > TX_AREA_END) {
620 		if (tail > priv(dev)->tx_head)
621 			return -1;
622 		start = TX_AREA_START;
623 		if (start + size > tail)
624 			return -1;
625 		priv(dev)->tx_head = start + size;
626 	} else {
627 		if (priv(dev)->tx_head < tail && (priv(dev)->tx_head + size) > tail)
628 			return -1;
629 		start = priv(dev)->tx_head;
630 		priv(dev)->tx_head += size;
631 	}
632 
633 	return start;
634 }
635 
636 static int
637 ether1_open (struct net_device *dev)
638 {
639 	if (request_irq(dev->irq, ether1_interrupt, 0, "ether1", dev))
640 		return -EAGAIN;
641 
642 	if (ether1_init_for_open (dev)) {
643 		free_irq (dev->irq, dev);
644 		return -EAGAIN;
645 	}
646 
647 	netif_start_queue(dev);
648 
649 	return 0;
650 }
651 
652 static void
653 ether1_timeout(struct net_device *dev)
654 {
655 	printk(KERN_WARNING "%s: transmit timeout, network cable problem?\n",
656 		dev->name);
657 	printk(KERN_WARNING "%s: resetting device\n", dev->name);
658 
659 	ether1_reset (dev);
660 
661 	if (ether1_init_for_open (dev))
662 		printk (KERN_ERR "%s: unable to restart interface\n", dev->name);
663 
664 	dev->stats.tx_errors++;
665 	netif_wake_queue(dev);
666 }
667 
668 static netdev_tx_t
669 ether1_sendpacket (struct sk_buff *skb, struct net_device *dev)
670 {
671 	int tmp, tst, nopaddr, txaddr, tbdaddr, dataddr;
672 	unsigned long flags;
673 	tx_t tx;
674 	tbd_t tbd;
675 	nop_t nop;
676 
677 	if (priv(dev)->restart) {
678 		printk(KERN_WARNING "%s: resetting device\n", dev->name);
679 
680 		ether1_reset(dev);
681 
682 		if (ether1_init_for_open(dev))
683 			printk(KERN_ERR "%s: unable to restart interface\n", dev->name);
684 		else
685 			priv(dev)->restart = 0;
686 	}
687 
688 	if (skb->len < ETH_ZLEN) {
689 		if (skb_padto(skb, ETH_ZLEN))
690 			goto out;
691 	}
692 
693 	/*
694 	 * insert packet followed by a nop
695 	 */
696 	txaddr = ether1_txalloc (dev, TX_SIZE);
697 	tbdaddr = ether1_txalloc (dev, TBD_SIZE);
698 	dataddr = ether1_txalloc (dev, skb->len);
699 	nopaddr = ether1_txalloc (dev, NOP_SIZE);
700 
701 	tx.tx_status = 0;
702 	tx.tx_command = CMD_TX | CMD_INTR;
703 	tx.tx_link = nopaddr;
704 	tx.tx_tbdoffset = tbdaddr;
705 	tbd.tbd_opts = TBD_EOL | skb->len;
706 	tbd.tbd_link = I82586_NULL;
707 	tbd.tbd_bufl = dataddr;
708 	tbd.tbd_bufh = 0;
709 	nop.nop_status = 0;
710 	nop.nop_command = CMD_NOP;
711 	nop.nop_link = nopaddr;
712 
713 	local_irq_save(flags);
714 	ether1_writebuffer (dev, &tx, txaddr, TX_SIZE);
715 	ether1_writebuffer (dev, &tbd, tbdaddr, TBD_SIZE);
716 	ether1_writebuffer (dev, skb->data, dataddr, skb->len);
717 	ether1_writebuffer (dev, &nop, nopaddr, NOP_SIZE);
718 	tmp = priv(dev)->tx_link;
719 	priv(dev)->tx_link = nopaddr;
720 
721 	/* now reset the previous nop pointer */
722 	ether1_writew(dev, txaddr, tmp, nop_t, nop_link, NORMALIRQS);
723 
724 	local_irq_restore(flags);
725 
726 	/* handle transmit */
727 
728 	/* check to see if we have room for a full sized ether frame */
729 	tmp = priv(dev)->tx_head;
730 	tst = ether1_txalloc (dev, TX_SIZE + TBD_SIZE + NOP_SIZE + ETH_FRAME_LEN);
731 	priv(dev)->tx_head = tmp;
732 	dev_kfree_skb (skb);
733 
734 	if (tst == -1)
735 		netif_stop_queue(dev);
736 
737  out:
738 	return NETDEV_TX_OK;
739 }
740 
741 static void
742 ether1_xmit_done (struct net_device *dev)
743 {
744 	nop_t nop;
745 	int caddr, tst;
746 
747 	caddr = priv(dev)->tx_tail;
748 
749 again:
750 	ether1_readbuffer (dev, &nop, caddr, NOP_SIZE);
751 
752 	switch (nop.nop_command & CMD_MASK) {
753 	case CMD_TDR:
754 		/* special case */
755 		if (ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS)
756 				!= (unsigned short)I82586_NULL) {
757 			ether1_writew(dev, SCB_CMDCUCSTART | SCB_CMDRXSTART, SCB_ADDR, scb_t,
758 				    scb_command, NORMALIRQS);
759 			writeb(CTRL_CA, REG_CONTROL);
760 		}
761 		priv(dev)->tx_tail = NOP_ADDR;
762 		return;
763 
764 	case CMD_NOP:
765 		if (nop.nop_link == caddr) {
766 			if (priv(dev)->initialising == 0)
767 				printk (KERN_WARNING "%s: strange command complete with no tx command!\n", dev->name);
768 			else
769 			        priv(dev)->initialising = 0;
770 			return;
771 		}
772 		if (caddr == nop.nop_link)
773 			return;
774 		caddr = nop.nop_link;
775 		goto again;
776 
777 	case CMD_TX:
778 		if (nop.nop_status & STAT_COMPLETE)
779 			break;
780 		printk (KERN_ERR "%s: strange command complete without completed command\n", dev->name);
781 		priv(dev)->restart = 1;
782 		return;
783 
784 	default:
785 		printk (KERN_WARNING "%s: strange command %d complete! (offset %04X)", dev->name,
786 			nop.nop_command & CMD_MASK, caddr);
787 		priv(dev)->restart = 1;
788 		return;
789 	}
790 
791 	while (nop.nop_status & STAT_COMPLETE) {
792 		if (nop.nop_status & STAT_OK) {
793 			dev->stats.tx_packets++;
794 			dev->stats.collisions += (nop.nop_status & STAT_COLLISIONS);
795 		} else {
796 			dev->stats.tx_errors++;
797 
798 			if (nop.nop_status & STAT_COLLAFTERTX)
799 				dev->stats.collisions++;
800 			if (nop.nop_status & STAT_NOCARRIER)
801 				dev->stats.tx_carrier_errors++;
802 			if (nop.nop_status & STAT_TXLOSTCTS)
803 				printk (KERN_WARNING "%s: cts lost\n", dev->name);
804 			if (nop.nop_status & STAT_TXSLOWDMA)
805 				dev->stats.tx_fifo_errors++;
806 			if (nop.nop_status & STAT_COLLEXCESSIVE)
807 				dev->stats.collisions += 16;
808 		}
809 
810 		if (nop.nop_link == caddr) {
811 			printk (KERN_ERR "%s: tx buffer chaining error: tx command points to itself\n", dev->name);
812 			break;
813 		}
814 
815 		caddr = nop.nop_link;
816 		ether1_readbuffer (dev, &nop, caddr, NOP_SIZE);
817 		if ((nop.nop_command & CMD_MASK) != CMD_NOP) {
818 			printk (KERN_ERR "%s: tx buffer chaining error: no nop after tx command\n", dev->name);
819 			break;
820 		}
821 
822 		if (caddr == nop.nop_link)
823 			break;
824 
825 		caddr = nop.nop_link;
826 		ether1_readbuffer (dev, &nop, caddr, NOP_SIZE);
827 		if ((nop.nop_command & CMD_MASK) != CMD_TX) {
828 			printk (KERN_ERR "%s: tx buffer chaining error: no tx command after nop\n", dev->name);
829 			break;
830 		}
831 	}
832 	priv(dev)->tx_tail = caddr;
833 
834 	caddr = priv(dev)->tx_head;
835 	tst = ether1_txalloc (dev, TX_SIZE + TBD_SIZE + NOP_SIZE + ETH_FRAME_LEN);
836 	priv(dev)->tx_head = caddr;
837 	if (tst != -1)
838 		netif_wake_queue(dev);
839 }
840 
841 static void
842 ether1_recv_done (struct net_device *dev)
843 {
844 	int status;
845 	int nexttail, rbdaddr;
846 	rbd_t rbd;
847 
848 	do {
849 		status = ether1_readw(dev, priv(dev)->rx_head, rfd_t, rfd_status, NORMALIRQS);
850 		if ((status & RFD_COMPLETE) == 0)
851 			break;
852 
853 		rbdaddr = ether1_readw(dev, priv(dev)->rx_head, rfd_t, rfd_rbdoffset, NORMALIRQS);
854 		ether1_readbuffer (dev, &rbd, rbdaddr, RBD_SIZE);
855 
856 		if ((rbd.rbd_status & (RBD_EOF | RBD_ACNTVALID)) == (RBD_EOF | RBD_ACNTVALID)) {
857 			int length = rbd.rbd_status & RBD_ACNT;
858 			struct sk_buff *skb;
859 
860 			length = (length + 1) & ~1;
861 			skb = netdev_alloc_skb(dev, length + 2);
862 
863 			if (skb) {
864 				skb_reserve (skb, 2);
865 
866 				ether1_readbuffer (dev, skb_put (skb, length), rbd.rbd_bufl, length);
867 
868 				skb->protocol = eth_type_trans (skb, dev);
869 				netif_rx (skb);
870 				dev->stats.rx_packets++;
871 			} else
872 				dev->stats.rx_dropped++;
873 		} else {
874 			printk(KERN_WARNING "%s: %s\n", dev->name,
875 				(rbd.rbd_status & RBD_EOF) ? "oversized packet" : "acnt not valid");
876 			dev->stats.rx_dropped++;
877 		}
878 
879 		nexttail = ether1_readw(dev, priv(dev)->rx_tail, rfd_t, rfd_link, NORMALIRQS);
880 		/* nexttail should be rx_head */
881 		if (nexttail != priv(dev)->rx_head)
882 			printk(KERN_ERR "%s: receiver buffer chaining error (%04X != %04X)\n",
883 				dev->name, nexttail, priv(dev)->rx_head);
884 		ether1_writew(dev, RFD_CMDEL | RFD_CMDSUSPEND, nexttail, rfd_t, rfd_command, NORMALIRQS);
885 		ether1_writew(dev, 0, priv(dev)->rx_tail, rfd_t, rfd_command, NORMALIRQS);
886 		ether1_writew(dev, 0, priv(dev)->rx_tail, rfd_t, rfd_status, NORMALIRQS);
887 		ether1_writew(dev, 0, priv(dev)->rx_tail, rfd_t, rfd_rbdoffset, NORMALIRQS);
888 
889 		priv(dev)->rx_tail = nexttail;
890 		priv(dev)->rx_head = ether1_readw(dev, priv(dev)->rx_head, rfd_t, rfd_link, NORMALIRQS);
891 	} while (1);
892 }
893 
894 static irqreturn_t
895 ether1_interrupt (int irq, void *dev_id)
896 {
897 	struct net_device *dev = (struct net_device *)dev_id;
898 	int status;
899 
900 	status = ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS);
901 
902 	if (status) {
903 		ether1_writew(dev, status & (SCB_STRNR | SCB_STCNA | SCB_STFR | SCB_STCX),
904 			    SCB_ADDR, scb_t, scb_command, NORMALIRQS);
905 		writeb(CTRL_CA | CTRL_ACK, REG_CONTROL);
906 		if (status & SCB_STCX) {
907 			ether1_xmit_done (dev);
908 		}
909 		if (status & SCB_STCNA) {
910 			if (priv(dev)->resetting == 0)
911 				printk (KERN_WARNING "%s: CU went not ready ???\n", dev->name);
912 			else
913 				priv(dev)->resetting += 1;
914 			if (ether1_readw(dev, SCB_ADDR, scb_t, scb_cbl_offset, NORMALIRQS)
915 					!= (unsigned short)I82586_NULL) {
916 				ether1_writew(dev, SCB_CMDCUCSTART, SCB_ADDR, scb_t, scb_command, NORMALIRQS);
917 				writeb(CTRL_CA, REG_CONTROL);
918 			}
919 			if (priv(dev)->resetting == 2)
920 				priv(dev)->resetting = 0;
921 		}
922 		if (status & SCB_STFR) {
923 			ether1_recv_done (dev);
924 		}
925 		if (status & SCB_STRNR) {
926 			if (ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS) & SCB_STRXSUSP) {
927 				printk (KERN_WARNING "%s: RU went not ready: RU suspended\n", dev->name);
928 				ether1_writew(dev, SCB_CMDRXRESUME, SCB_ADDR, scb_t, scb_command, NORMALIRQS);
929 				writeb(CTRL_CA, REG_CONTROL);
930 				dev->stats.rx_dropped++;	/* we suspended due to lack of buffer space */
931 			} else
932 				printk(KERN_WARNING "%s: RU went not ready: %04X\n", dev->name,
933 					ether1_readw(dev, SCB_ADDR, scb_t, scb_status, NORMALIRQS));
934 			printk (KERN_WARNING "RU ptr = %04X\n", ether1_readw(dev, SCB_ADDR, scb_t, scb_rfa_offset,
935 						NORMALIRQS));
936 		}
937 	} else
938 		writeb(CTRL_ACK, REG_CONTROL);
939 
940 	return IRQ_HANDLED;
941 }
942 
943 static int
944 ether1_close (struct net_device *dev)
945 {
946 	ether1_reset (dev);
947 
948 	free_irq(dev->irq, dev);
949 
950 	return 0;
951 }
952 
953 /*
954  * Set or clear the multicast filter for this adaptor.
955  * num_addrs == -1	Promiscuous mode, receive all packets.
956  * num_addrs == 0	Normal mode, clear multicast list.
957  * num_addrs > 0	Multicast mode, receive normal and MC packets, and do
958  *			best-effort filtering.
959  */
960 static void
961 ether1_setmulticastlist (struct net_device *dev)
962 {
963 }
964 
965 /* ------------------------------------------------------------------------- */
966 
967 static void ether1_banner(void)
968 {
969 	static unsigned int version_printed = 0;
970 
971 	if (net_debug && version_printed++ == 0)
972 		printk(KERN_INFO "%s", version);
973 }
974 
975 static const struct net_device_ops ether1_netdev_ops = {
976 	.ndo_open		= ether1_open,
977 	.ndo_stop		= ether1_close,
978 	.ndo_start_xmit		= ether1_sendpacket,
979 	.ndo_set_rx_mode	= ether1_setmulticastlist,
980 	.ndo_tx_timeout		= ether1_timeout,
981 	.ndo_validate_addr	= eth_validate_addr,
982 	.ndo_set_mac_address	= eth_mac_addr,
983 };
984 
985 static int
986 ether1_probe(struct expansion_card *ec, const struct ecard_id *id)
987 {
988 	struct net_device *dev;
989 	int i, ret = 0;
990 
991 	ether1_banner();
992 
993 	ret = ecard_request_resources(ec);
994 	if (ret)
995 		goto out;
996 
997 	dev = alloc_etherdev(sizeof(struct ether1_priv));
998 	if (!dev) {
999 		ret = -ENOMEM;
1000 		goto release;
1001 	}
1002 
1003 	SET_NETDEV_DEV(dev, &ec->dev);
1004 
1005 	dev->irq = ec->irq;
1006 	priv(dev)->base = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
1007 	if (!priv(dev)->base) {
1008 		ret = -ENOMEM;
1009 		goto free;
1010 	}
1011 
1012 	if ((priv(dev)->bus_type = ether1_reset(dev)) == 0) {
1013 		ret = -ENODEV;
1014 		goto free;
1015 	}
1016 
1017 	for (i = 0; i < 6; i++)
1018 		dev->dev_addr[i] = readb(IDPROM_ADDRESS + (i << 2));
1019 
1020 	if (ether1_init_2(dev)) {
1021 		ret = -ENODEV;
1022 		goto free;
1023 	}
1024 
1025 	dev->netdev_ops		= &ether1_netdev_ops;
1026 	dev->watchdog_timeo	= 5 * HZ / 100;
1027 
1028 	ret = register_netdev(dev);
1029 	if (ret)
1030 		goto free;
1031 
1032 	printk(KERN_INFO "%s: ether1 in slot %d, %pM\n",
1033 		dev->name, ec->slot_no, dev->dev_addr);
1034 
1035 	ecard_set_drvdata(ec, dev);
1036 	return 0;
1037 
1038  free:
1039 	free_netdev(dev);
1040  release:
1041 	ecard_release_resources(ec);
1042  out:
1043 	return ret;
1044 }
1045 
1046 static void ether1_remove(struct expansion_card *ec)
1047 {
1048 	struct net_device *dev = ecard_get_drvdata(ec);
1049 
1050 	ecard_set_drvdata(ec, NULL);
1051 
1052 	unregister_netdev(dev);
1053 	free_netdev(dev);
1054 	ecard_release_resources(ec);
1055 }
1056 
1057 static const struct ecard_id ether1_ids[] = {
1058 	{ MANU_ACORN, PROD_ACORN_ETHER1 },
1059 	{ 0xffff, 0xffff }
1060 };
1061 
1062 static struct ecard_driver ether1_driver = {
1063 	.probe		= ether1_probe,
1064 	.remove		= ether1_remove,
1065 	.id_table	= ether1_ids,
1066 	.drv = {
1067 		.name	= "ether1",
1068 	},
1069 };
1070 
1071 static int __init ether1_init(void)
1072 {
1073 	return ecard_register_driver(&ether1_driver);
1074 }
1075 
1076 static void __exit ether1_exit(void)
1077 {
1078 	ecard_remove_driver(&ether1_driver);
1079 }
1080 
1081 module_init(ether1_init);
1082 module_exit(ether1_exit);
1083 
1084 MODULE_LICENSE("GPL");
1085