xref: /linux/drivers/pnp/pnpbios/rsparser.c (revision 13abf8130139c2ccd4962a7e5a8902be5e6cb5a7)
1 /*
2  * rsparser.c - parses and encodes pnpbios resource data streams
3  *
4  */
5 
6 #include <linux/config.h>
7 #include <linux/ctype.h>
8 #include <linux/pnp.h>
9 #include <linux/pnpbios.h>
10 
11 #ifdef CONFIG_PCI
12 #include <linux/pci.h>
13 #else
14 inline void pcibios_penalize_isa_irq(int irq, int active) {}
15 #endif /* CONFIG_PCI */
16 
17 #include "pnpbios.h"
18 
19 /* standard resource tags */
20 #define SMALL_TAG_PNPVERNO		0x01
21 #define SMALL_TAG_LOGDEVID		0x02
22 #define SMALL_TAG_COMPATDEVID		0x03
23 #define SMALL_TAG_IRQ			0x04
24 #define SMALL_TAG_DMA			0x05
25 #define SMALL_TAG_STARTDEP		0x06
26 #define SMALL_TAG_ENDDEP		0x07
27 #define SMALL_TAG_PORT			0x08
28 #define SMALL_TAG_FIXEDPORT		0x09
29 #define SMALL_TAG_VENDOR		0x0e
30 #define SMALL_TAG_END			0x0f
31 #define LARGE_TAG			0x80
32 #define LARGE_TAG_MEM			0x81
33 #define LARGE_TAG_ANSISTR		0x82
34 #define LARGE_TAG_UNICODESTR		0x83
35 #define LARGE_TAG_VENDOR		0x84
36 #define LARGE_TAG_MEM32			0x85
37 #define LARGE_TAG_FIXEDMEM32		0x86
38 
39 /*
40  * Resource Data Stream Format:
41  *
42  * Allocated Resources (required)
43  * end tag ->
44  * Resource Configuration Options (optional)
45  * end tag ->
46  * Compitable Device IDs (optional)
47  * final end tag ->
48  */
49 
50 /*
51  * Allocated Resources
52  */
53 
54 static void
55 pnpbios_parse_allocated_irqresource(struct pnp_resource_table * res, int irq)
56 {
57 	int i = 0;
58 	while (!(res->irq_resource[i].flags & IORESOURCE_UNSET) && i < PNP_MAX_IRQ) i++;
59 	if (i < PNP_MAX_IRQ) {
60 		res->irq_resource[i].flags = IORESOURCE_IRQ;  // Also clears _UNSET flag
61 		if (irq == -1) {
62 			res->irq_resource[i].flags |= IORESOURCE_DISABLED;
63 			return;
64 		}
65 		res->irq_resource[i].start =
66 		res->irq_resource[i].end = (unsigned long) irq;
67 		pcibios_penalize_isa_irq(irq, 1);
68 	}
69 }
70 
71 static void
72 pnpbios_parse_allocated_dmaresource(struct pnp_resource_table * res, int dma)
73 {
74 	int i = 0;
75 	while (i < PNP_MAX_DMA &&
76 			!(res->dma_resource[i].flags & IORESOURCE_UNSET))
77 		i++;
78 	if (i < PNP_MAX_DMA) {
79 		res->dma_resource[i].flags = IORESOURCE_DMA;  // Also clears _UNSET flag
80 		if (dma == -1) {
81 			res->dma_resource[i].flags |= IORESOURCE_DISABLED;
82 			return;
83 		}
84 		res->dma_resource[i].start =
85 		res->dma_resource[i].end = (unsigned long) dma;
86 	}
87 }
88 
89 static void
90 pnpbios_parse_allocated_ioresource(struct pnp_resource_table * res, int io, int len)
91 {
92 	int i = 0;
93 	while (!(res->port_resource[i].flags & IORESOURCE_UNSET) && i < PNP_MAX_PORT) i++;
94 	if (i < PNP_MAX_PORT) {
95 		res->port_resource[i].flags = IORESOURCE_IO;  // Also clears _UNSET flag
96 		if (len <= 0 || (io + len -1) >= 0x10003) {
97 			res->port_resource[i].flags |= IORESOURCE_DISABLED;
98 			return;
99 		}
100 		res->port_resource[i].start = (unsigned long) io;
101 		res->port_resource[i].end = (unsigned long)(io + len - 1);
102 	}
103 }
104 
105 static void
106 pnpbios_parse_allocated_memresource(struct pnp_resource_table * res, int mem, int len)
107 {
108 	int i = 0;
109 	while (!(res->mem_resource[i].flags & IORESOURCE_UNSET) && i < PNP_MAX_MEM) i++;
110 	if (i < PNP_MAX_MEM) {
111 		res->mem_resource[i].flags = IORESOURCE_MEM;  // Also clears _UNSET flag
112 		if (len <= 0) {
113 			res->mem_resource[i].flags |= IORESOURCE_DISABLED;
114 			return;
115 		}
116 		res->mem_resource[i].start = (unsigned long) mem;
117 		res->mem_resource[i].end = (unsigned long)(mem + len - 1);
118 	}
119 }
120 
121 static unsigned char *
122 pnpbios_parse_allocated_resource_data(unsigned char * p, unsigned char * end, struct pnp_resource_table * res)
123 {
124 	unsigned int len, tag;
125 	int io, size, mask, i;
126 
127 	if (!p)
128 		return NULL;
129 
130 	/* Blank the resource table values */
131 	pnp_init_resource_table(res);
132 
133 	while ((char *)p < (char *)end) {
134 
135 		/* determine the type of tag */
136 		if (p[0] & LARGE_TAG) { /* large tag */
137 			len = (p[2] << 8) | p[1];
138 			tag = p[0];
139 		} else { /* small tag */
140 			len = p[0] & 0x07;
141 			tag = ((p[0]>>3) & 0x0f);
142 		}
143 
144 		switch (tag) {
145 
146 		case LARGE_TAG_MEM:
147 			if (len != 9)
148 				goto len_err;
149 			io = *(short *) &p[4];
150 			size = *(short *) &p[10];
151 			pnpbios_parse_allocated_memresource(res, io, size);
152 			break;
153 
154 		case LARGE_TAG_ANSISTR:
155 			/* ignore this for now */
156 			break;
157 
158 		case LARGE_TAG_VENDOR:
159 			/* do nothing */
160 			break;
161 
162 		case LARGE_TAG_MEM32:
163 			if (len != 17)
164 				goto len_err;
165 			io = *(int *) &p[4];
166 			size = *(int *) &p[16];
167 			pnpbios_parse_allocated_memresource(res, io, size);
168 			break;
169 
170 		case LARGE_TAG_FIXEDMEM32:
171 			if (len != 9)
172 				goto len_err;
173 			io = *(int *) &p[4];
174 			size = *(int *) &p[8];
175 			pnpbios_parse_allocated_memresource(res, io, size);
176 			break;
177 
178 		case SMALL_TAG_IRQ:
179 			if (len < 2 || len > 3)
180 				goto len_err;
181 			io = -1;
182 			mask= p[1] + p[2]*256;
183 			for (i=0;i<16;i++, mask=mask>>1)
184 				if(mask & 0x01) io=i;
185 			pnpbios_parse_allocated_irqresource(res, io);
186 			break;
187 
188 		case SMALL_TAG_DMA:
189 			if (len != 2)
190 				goto len_err;
191 			io = -1;
192 			mask = p[1];
193 			for (i=0;i<8;i++, mask = mask>>1)
194 				if(mask & 0x01) io=i;
195 			pnpbios_parse_allocated_dmaresource(res, io);
196 			break;
197 
198 		case SMALL_TAG_PORT:
199 			if (len != 7)
200 				goto len_err;
201 			io = p[2] + p[3] *256;
202 			size = p[7];
203 			pnpbios_parse_allocated_ioresource(res, io, size);
204 			break;
205 
206 		case SMALL_TAG_VENDOR:
207 			/* do nothing */
208 			break;
209 
210 		case SMALL_TAG_FIXEDPORT:
211 			if (len != 3)
212 				goto len_err;
213 			io = p[1] + p[2] * 256;
214 			size = p[3];
215 			pnpbios_parse_allocated_ioresource(res, io, size);
216 			break;
217 
218 		case SMALL_TAG_END:
219 			p = p + 2;
220         		return (unsigned char *)p;
221 			break;
222 
223 		default: /* an unkown tag */
224 			len_err:
225 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
226 			break;
227 		}
228 
229 		/* continue to the next tag */
230 		if (p[0] & LARGE_TAG)
231 			p += len + 3;
232 		else
233 			p += len + 1;
234 	}
235 
236 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
237 
238 	return NULL;
239 }
240 
241 
242 /*
243  * Resource Configuration Options
244  */
245 
246 static void
247 pnpbios_parse_mem_option(unsigned char *p, int size, struct pnp_option *option)
248 {
249 	struct pnp_mem * mem;
250 	mem = pnpbios_kmalloc(sizeof(struct pnp_mem), GFP_KERNEL);
251 	if (!mem)
252 		return;
253 	mem->min = ((p[5] << 8) | p[4]) << 8;
254 	mem->max = ((p[7] << 8) | p[6]) << 8;
255 	mem->align = (p[9] << 8) | p[8];
256 	mem->size = ((p[11] << 8) | p[10]) << 8;
257 	mem->flags = p[3];
258 	pnp_register_mem_resource(option,mem);
259 	return;
260 }
261 
262 static void
263 pnpbios_parse_mem32_option(unsigned char *p, int size, struct pnp_option *option)
264 {
265 	struct pnp_mem * mem;
266 	mem = pnpbios_kmalloc(sizeof(struct pnp_mem), GFP_KERNEL);
267 	if (!mem)
268 		return;
269 	mem->min = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
270 	mem->max = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
271 	mem->align = (p[15] << 24) | (p[14] << 16) | (p[13] << 8) | p[12];
272 	mem->size = (p[19] << 24) | (p[18] << 16) | (p[17] << 8) | p[16];
273 	mem->flags = p[3];
274 	pnp_register_mem_resource(option,mem);
275 	return;
276 }
277 
278 static void
279 pnpbios_parse_fixed_mem32_option(unsigned char *p, int size, struct pnp_option *option)
280 {
281 	struct pnp_mem * mem;
282 	mem = pnpbios_kmalloc(sizeof(struct pnp_mem), GFP_KERNEL);
283 	if (!mem)
284 		return;
285 	mem->min = mem->max = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
286 	mem->size = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
287 	mem->align = 0;
288 	mem->flags = p[3];
289 	pnp_register_mem_resource(option,mem);
290 	return;
291 }
292 
293 static void
294 pnpbios_parse_irq_option(unsigned char *p, int size, struct pnp_option *option)
295 {
296 	struct pnp_irq * irq;
297 	unsigned long bits;
298 
299 	irq = pnpbios_kmalloc(sizeof(struct pnp_irq), GFP_KERNEL);
300 	if (!irq)
301 		return;
302 	bits = (p[2] << 8) | p[1];
303 	bitmap_copy(irq->map, &bits, 16);
304 	if (size > 2)
305 		irq->flags = p[3];
306 	else
307 		irq->flags = IORESOURCE_IRQ_HIGHEDGE;
308 	pnp_register_irq_resource(option,irq);
309 	return;
310 }
311 
312 static void
313 pnpbios_parse_dma_option(unsigned char *p, int size, struct pnp_option *option)
314 {
315 	struct pnp_dma * dma;
316 	dma = pnpbios_kmalloc(sizeof(struct pnp_dma), GFP_KERNEL);
317 	if (!dma)
318 		return;
319 	dma->map = p[1];
320 	dma->flags = p[2];
321 	pnp_register_dma_resource(option,dma);
322 	return;
323 }
324 
325 static void
326 pnpbios_parse_port_option(unsigned char *p, int size, struct pnp_option *option)
327 {
328 	struct pnp_port * port;
329 	port = pnpbios_kmalloc(sizeof(struct pnp_port), GFP_KERNEL);
330 	if (!port)
331 		return;
332 	port->min = (p[3] << 8) | p[2];
333 	port->max = (p[5] << 8) | p[4];
334 	port->align = p[6];
335 	port->size = p[7];
336 	port->flags = p[1] ? PNP_PORT_FLAG_16BITADDR : 0;
337 	pnp_register_port_resource(option,port);
338 	return;
339 }
340 
341 static void
342 pnpbios_parse_fixed_port_option(unsigned char *p, int size, struct pnp_option *option)
343 {
344 	struct pnp_port * port;
345 	port = pnpbios_kmalloc(sizeof(struct pnp_port), GFP_KERNEL);
346 	if (!port)
347 		return;
348 	port->min = port->max = (p[2] << 8) | p[1];
349 	port->size = p[3];
350 	port->align = 0;
351 	port->flags = PNP_PORT_FLAG_FIXED;
352 	pnp_register_port_resource(option,port);
353 	return;
354 }
355 
356 static unsigned char *
357 pnpbios_parse_resource_option_data(unsigned char * p, unsigned char * end, struct pnp_dev *dev)
358 {
359 	unsigned int len, tag;
360 	int priority = 0;
361 	struct pnp_option *option, *option_independent;
362 
363 	if (!p)
364 		return NULL;
365 
366 	option_independent = option = pnp_register_independent_option(dev);
367 	if (!option)
368 		return NULL;
369 
370 	while ((char *)p < (char *)end) {
371 
372 		/* determine the type of tag */
373 		if (p[0] & LARGE_TAG) { /* large tag */
374 			len = (p[2] << 8) | p[1];
375 			tag = p[0];
376 		} else { /* small tag */
377 			len = p[0] & 0x07;
378 			tag = ((p[0]>>3) & 0x0f);
379 		}
380 
381 		switch (tag) {
382 
383 		case LARGE_TAG_MEM:
384 			if (len != 9)
385 				goto len_err;
386 			pnpbios_parse_mem_option(p, len, option);
387 			break;
388 
389 		case LARGE_TAG_MEM32:
390 			if (len != 17)
391 				goto len_err;
392 			pnpbios_parse_mem32_option(p, len, option);
393 			break;
394 
395 		case LARGE_TAG_FIXEDMEM32:
396 			if (len != 9)
397 				goto len_err;
398 			pnpbios_parse_fixed_mem32_option(p, len, option);
399 			break;
400 
401 		case SMALL_TAG_IRQ:
402 			if (len < 2 || len > 3)
403 				goto len_err;
404 			pnpbios_parse_irq_option(p, len, option);
405 			break;
406 
407 		case SMALL_TAG_DMA:
408 			if (len != 2)
409 				goto len_err;
410 			pnpbios_parse_dma_option(p, len, option);
411 			break;
412 
413 		case SMALL_TAG_PORT:
414 			if (len != 7)
415 				goto len_err;
416 			pnpbios_parse_port_option(p, len, option);
417 			break;
418 
419 		case SMALL_TAG_VENDOR:
420 			/* do nothing */
421 			break;
422 
423 		case SMALL_TAG_FIXEDPORT:
424 			if (len != 3)
425 				goto len_err;
426 			pnpbios_parse_fixed_port_option(p, len, option);
427 			break;
428 
429 		case SMALL_TAG_STARTDEP:
430 			if (len > 1)
431 				goto len_err;
432 			priority = 0x100 | PNP_RES_PRIORITY_ACCEPTABLE;
433 			if (len > 0)
434 				priority = 0x100 | p[1];
435 			option = pnp_register_dependent_option(dev, priority);
436 			if (!option)
437 				return NULL;
438 			break;
439 
440 		case SMALL_TAG_ENDDEP:
441 			if (len != 0)
442 				goto len_err;
443 			if (option_independent == option)
444 				printk(KERN_WARNING "PnPBIOS: Missing SMALL_TAG_STARTDEP tag\n");
445 			option = option_independent;
446 			break;
447 
448 		case SMALL_TAG_END:
449 			if (option_independent != option)
450 				printk(KERN_WARNING "PnPBIOS: Missing SMALL_TAG_ENDDEP tag\n");
451 			p = p + 2;
452         		return (unsigned char *)p;
453 			break;
454 
455 		default: /* an unkown tag */
456 			len_err:
457 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
458 			break;
459 		}
460 
461 		/* continue to the next tag */
462 		if (p[0] & LARGE_TAG)
463 			p += len + 3;
464 		else
465 			p += len + 1;
466 	}
467 
468 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
469 
470 	return NULL;
471 }
472 
473 
474 /*
475  * Compatible Device IDs
476  */
477 
478 #define HEX(id,a) hex[((id)>>a) & 15]
479 #define CHAR(id,a) (0x40 + (((id)>>a) & 31))
480 //
481 
482 void pnpid32_to_pnpid(u32 id, char *str)
483 {
484 	const char *hex = "0123456789abcdef";
485 
486 	id = be32_to_cpu(id);
487 	str[0] = CHAR(id, 26);
488 	str[1] = CHAR(id, 21);
489 	str[2] = CHAR(id,16);
490 	str[3] = HEX(id, 12);
491 	str[4] = HEX(id, 8);
492 	str[5] = HEX(id, 4);
493 	str[6] = HEX(id, 0);
494 	str[7] = '\0';
495 
496 	return;
497 }
498 //
499 #undef CHAR
500 #undef HEX
501 
502 static unsigned char *
503 pnpbios_parse_compatible_ids(unsigned char *p, unsigned char *end, struct pnp_dev *dev)
504 {
505 	int len, tag;
506 	char id[8];
507 	struct pnp_id *dev_id;
508 
509 	if (!p)
510 		return NULL;
511 
512 	while ((char *)p < (char *)end) {
513 
514 		/* determine the type of tag */
515 		if (p[0] & LARGE_TAG) { /* large tag */
516 			len = (p[2] << 8) | p[1];
517 			tag = p[0];
518 		} else { /* small tag */
519 			len = p[0] & 0x07;
520 			tag = ((p[0]>>3) & 0x0f);
521 		}
522 
523 		switch (tag) {
524 
525 		case LARGE_TAG_ANSISTR:
526 			strncpy(dev->name, p + 3, len >= PNP_NAME_LEN ? PNP_NAME_LEN - 2 : len);
527 			dev->name[len >= PNP_NAME_LEN ? PNP_NAME_LEN - 1 : len] = '\0';
528 			break;
529 
530 		case SMALL_TAG_COMPATDEVID: /* compatible ID */
531 			if (len != 4)
532 				goto len_err;
533 			dev_id =  pnpbios_kmalloc(sizeof (struct pnp_id), GFP_KERNEL);
534 			if (!dev_id)
535 				return NULL;
536 			memset(dev_id, 0, sizeof(struct pnp_id));
537 			pnpid32_to_pnpid(p[1] | p[2] << 8 | p[3] << 16 | p[4] << 24,id);
538 			memcpy(&dev_id->id, id, 7);
539 			pnp_add_id(dev_id, dev);
540 			break;
541 
542 		case SMALL_TAG_END:
543 			p = p + 2;
544         		return (unsigned char *)p;
545 			break;
546 
547 		default: /* an unkown tag */
548 			len_err:
549 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
550 			break;
551 		}
552 
553 		/* continue to the next tag */
554 		if (p[0] & LARGE_TAG)
555 			p += len + 3;
556 		else
557 			p += len + 1;
558 	}
559 
560 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
561 
562 	return NULL;
563 }
564 
565 
566 /*
567  * Allocated Resource Encoding
568  */
569 
570 static void pnpbios_encode_mem(unsigned char *p, struct resource * res)
571 {
572 	unsigned long base = res->start;
573 	unsigned long len = res->end - res->start + 1;
574 	p[4] = (base >> 8) & 0xff;
575 	p[5] = ((base >> 8) >> 8) & 0xff;
576 	p[6] = (base >> 8) & 0xff;
577 	p[7] = ((base >> 8) >> 8) & 0xff;
578 	p[10] = (len >> 8) & 0xff;
579 	p[11] = ((len >> 8) >> 8) & 0xff;
580 	return;
581 }
582 
583 static void pnpbios_encode_mem32(unsigned char *p, struct resource * res)
584 {
585 	unsigned long base = res->start;
586 	unsigned long len = res->end - res->start + 1;
587 	p[4] = base & 0xff;
588 	p[5] = (base >> 8) & 0xff;
589 	p[6] = (base >> 16) & 0xff;
590 	p[7] = (base >> 24) & 0xff;
591 	p[8] = base & 0xff;
592 	p[9] = (base >> 8) & 0xff;
593 	p[10] = (base >> 16) & 0xff;
594 	p[11] = (base >> 24) & 0xff;
595 	p[16] = len & 0xff;
596 	p[17] = (len >> 8) & 0xff;
597 	p[18] = (len >> 16) & 0xff;
598 	p[19] = (len >> 24) & 0xff;
599 	return;
600 }
601 
602 static void pnpbios_encode_fixed_mem32(unsigned char *p, struct resource * res)
603 {	unsigned long base = res->start;
604 	unsigned long len = res->end - res->start + 1;
605 	p[4] = base & 0xff;
606 	p[5] = (base >> 8) & 0xff;
607 	p[6] = (base >> 16) & 0xff;
608 	p[7] = (base >> 24) & 0xff;
609 	p[8] = len & 0xff;
610 	p[9] = (len >> 8) & 0xff;
611 	p[10] = (len >> 16) & 0xff;
612 	p[11] = (len >> 24) & 0xff;
613 	return;
614 }
615 
616 static void pnpbios_encode_irq(unsigned char *p, struct resource * res)
617 {
618 	unsigned long map = 0;
619 	map = 1 << res->start;
620 	p[1] = map & 0xff;
621 	p[2] = (map >> 8) & 0xff;
622 	return;
623 }
624 
625 static void pnpbios_encode_dma(unsigned char *p, struct resource * res)
626 {
627 	unsigned long map = 0;
628 	map = 1 << res->start;
629 	p[1] = map & 0xff;
630 	return;
631 }
632 
633 static void pnpbios_encode_port(unsigned char *p, struct resource * res)
634 {
635 	unsigned long base = res->start;
636 	unsigned long len = res->end - res->start + 1;
637 	p[2] = base & 0xff;
638 	p[3] = (base >> 8) & 0xff;
639 	p[4] = base & 0xff;
640 	p[5] = (base >> 8) & 0xff;
641 	p[7] = len & 0xff;
642 	return;
643 }
644 
645 static void pnpbios_encode_fixed_port(unsigned char *p, struct resource * res)
646 {
647 	unsigned long base = res->start;
648 	unsigned long len = res->end - res->start + 1;
649 	p[1] = base & 0xff;
650 	p[2] = (base >> 8) & 0xff;
651 	p[3] = len & 0xff;
652 	return;
653 }
654 
655 static unsigned char *
656 pnpbios_encode_allocated_resource_data(unsigned char * p, unsigned char * end, struct pnp_resource_table * res)
657 {
658 	unsigned int len, tag;
659 	int port = 0, irq = 0, dma = 0, mem = 0;
660 
661 	if (!p)
662 		return NULL;
663 
664 	while ((char *)p < (char *)end) {
665 
666 		/* determine the type of tag */
667 		if (p[0] & LARGE_TAG) { /* large tag */
668 			len = (p[2] << 8) | p[1];
669 			tag = p[0];
670 		} else { /* small tag */
671 			len = p[0] & 0x07;
672 			tag = ((p[0]>>3) & 0x0f);
673 		}
674 
675 		switch (tag) {
676 
677 		case LARGE_TAG_MEM:
678 			if (len != 9)
679 				goto len_err;
680 			pnpbios_encode_mem(p, &res->mem_resource[mem]);
681 			mem++;
682 			break;
683 
684 		case LARGE_TAG_MEM32:
685 			if (len != 17)
686 				goto len_err;
687 			pnpbios_encode_mem32(p, &res->mem_resource[mem]);
688 			mem++;
689 			break;
690 
691 		case LARGE_TAG_FIXEDMEM32:
692 			if (len != 9)
693 				goto len_err;
694 			pnpbios_encode_fixed_mem32(p, &res->mem_resource[mem]);
695 			mem++;
696 			break;
697 
698 		case SMALL_TAG_IRQ:
699 			if (len < 2 || len > 3)
700 				goto len_err;
701 			pnpbios_encode_irq(p, &res->irq_resource[irq]);
702 			irq++;
703 			break;
704 
705 		case SMALL_TAG_DMA:
706 			if (len != 2)
707 				goto len_err;
708 			pnpbios_encode_dma(p, &res->dma_resource[dma]);
709 			dma++;
710 			break;
711 
712 		case SMALL_TAG_PORT:
713 			if (len != 7)
714 				goto len_err;
715 			pnpbios_encode_port(p, &res->port_resource[port]);
716 			port++;
717 			break;
718 
719 		case SMALL_TAG_VENDOR:
720 			/* do nothing */
721 			break;
722 
723 		case SMALL_TAG_FIXEDPORT:
724 			if (len != 3)
725 				goto len_err;
726 			pnpbios_encode_fixed_port(p, &res->port_resource[port]);
727 			port++;
728 			break;
729 
730 		case SMALL_TAG_END:
731 			p = p + 2;
732         		return (unsigned char *)p;
733 			break;
734 
735 		default: /* an unkown tag */
736 			len_err:
737 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
738 			break;
739 		}
740 
741 		/* continue to the next tag */
742 		if (p[0] & LARGE_TAG)
743 			p += len + 3;
744 		else
745 			p += len + 1;
746 	}
747 
748 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
749 
750 	return NULL;
751 }
752 
753 
754 /*
755  * Core Parsing Functions
756  */
757 
758 int
759 pnpbios_parse_data_stream(struct pnp_dev *dev, struct pnp_bios_node * node)
760 {
761 	unsigned char * p = (char *)node->data;
762 	unsigned char * end = (char *)(node->data + node->size);
763 	p = pnpbios_parse_allocated_resource_data(p,end,&dev->res);
764 	if (!p)
765 		return -EIO;
766 	p = pnpbios_parse_resource_option_data(p,end,dev);
767 	if (!p)
768 		return -EIO;
769 	p = pnpbios_parse_compatible_ids(p,end,dev);
770 	if (!p)
771 		return -EIO;
772 	return 0;
773 }
774 
775 int
776 pnpbios_read_resources_from_node(struct pnp_resource_table *res,
777 				 struct pnp_bios_node * node)
778 {
779 	unsigned char * p = (char *)node->data;
780 	unsigned char * end = (char *)(node->data + node->size);
781 	p = pnpbios_parse_allocated_resource_data(p,end,res);
782 	if (!p)
783 		return -EIO;
784 	return 0;
785 }
786 
787 int
788 pnpbios_write_resources_to_node(struct pnp_resource_table *res,
789 				struct pnp_bios_node * node)
790 {
791 	unsigned char * p = (char *)node->data;
792 	unsigned char * end = (char *)(node->data + node->size);
793 	p = pnpbios_encode_allocated_resource_data(p,end,res);
794 	if (!p)
795 		return -EIO;
796 	return 0;
797 }
798