xref: /openbmc/linux/drivers/pnp/pnpbios/rsparser.c (revision 64c70b1c)
1 /*
2  * rsparser.c - parses and encodes pnpbios resource data streams
3  *
4  */
5 
6 #include <linux/ctype.h>
7 #include <linux/pnp.h>
8 #include <linux/pnpbios.h>
9 #include <linux/string.h>
10 #include <linux/slab.h>
11 
12 #ifdef CONFIG_PCI
13 #include <linux/pci.h>
14 #else
15 inline void pcibios_penalize_isa_irq(int irq, int active) {}
16 #endif /* CONFIG_PCI */
17 
18 #include "pnpbios.h"
19 
20 /* standard resource tags */
21 #define SMALL_TAG_PNPVERNO		0x01
22 #define SMALL_TAG_LOGDEVID		0x02
23 #define SMALL_TAG_COMPATDEVID		0x03
24 #define SMALL_TAG_IRQ			0x04
25 #define SMALL_TAG_DMA			0x05
26 #define SMALL_TAG_STARTDEP		0x06
27 #define SMALL_TAG_ENDDEP		0x07
28 #define SMALL_TAG_PORT			0x08
29 #define SMALL_TAG_FIXEDPORT		0x09
30 #define SMALL_TAG_VENDOR		0x0e
31 #define SMALL_TAG_END			0x0f
32 #define LARGE_TAG			0x80
33 #define LARGE_TAG_MEM			0x81
34 #define LARGE_TAG_ANSISTR		0x82
35 #define LARGE_TAG_UNICODESTR		0x83
36 #define LARGE_TAG_VENDOR		0x84
37 #define LARGE_TAG_MEM32			0x85
38 #define LARGE_TAG_FIXEDMEM32		0x86
39 
40 /*
41  * Resource Data Stream Format:
42  *
43  * Allocated Resources (required)
44  * end tag ->
45  * Resource Configuration Options (optional)
46  * end tag ->
47  * Compitable Device IDs (optional)
48  * final end tag ->
49  */
50 
51 /*
52  * Allocated Resources
53  */
54 
55 static void
56 pnpbios_parse_allocated_irqresource(struct pnp_resource_table * res, int irq)
57 {
58 	int i = 0;
59 	while (!(res->irq_resource[i].flags & IORESOURCE_UNSET) && i < PNP_MAX_IRQ) i++;
60 	if (i < PNP_MAX_IRQ) {
61 		res->irq_resource[i].flags = IORESOURCE_IRQ;  // Also clears _UNSET flag
62 		if (irq == -1) {
63 			res->irq_resource[i].flags |= IORESOURCE_DISABLED;
64 			return;
65 		}
66 		res->irq_resource[i].start =
67 		res->irq_resource[i].end = (unsigned long) irq;
68 		pcibios_penalize_isa_irq(irq, 1);
69 	}
70 }
71 
72 static void
73 pnpbios_parse_allocated_dmaresource(struct pnp_resource_table * res, int dma)
74 {
75 	int i = 0;
76 	while (i < PNP_MAX_DMA &&
77 			!(res->dma_resource[i].flags & IORESOURCE_UNSET))
78 		i++;
79 	if (i < PNP_MAX_DMA) {
80 		res->dma_resource[i].flags = IORESOURCE_DMA;  // Also clears _UNSET flag
81 		if (dma == -1) {
82 			res->dma_resource[i].flags |= IORESOURCE_DISABLED;
83 			return;
84 		}
85 		res->dma_resource[i].start =
86 		res->dma_resource[i].end = (unsigned long) dma;
87 	}
88 }
89 
90 static void
91 pnpbios_parse_allocated_ioresource(struct pnp_resource_table * res, int io, int len)
92 {
93 	int i = 0;
94 	while (!(res->port_resource[i].flags & IORESOURCE_UNSET) && i < PNP_MAX_PORT) i++;
95 	if (i < PNP_MAX_PORT) {
96 		res->port_resource[i].flags = IORESOURCE_IO;  // Also clears _UNSET flag
97 		if (len <= 0 || (io + len -1) >= 0x10003) {
98 			res->port_resource[i].flags |= IORESOURCE_DISABLED;
99 			return;
100 		}
101 		res->port_resource[i].start = (unsigned long) io;
102 		res->port_resource[i].end = (unsigned long)(io + len - 1);
103 	}
104 }
105 
106 static void
107 pnpbios_parse_allocated_memresource(struct pnp_resource_table * res, int mem, int len)
108 {
109 	int i = 0;
110 	while (!(res->mem_resource[i].flags & IORESOURCE_UNSET) && i < PNP_MAX_MEM) i++;
111 	if (i < PNP_MAX_MEM) {
112 		res->mem_resource[i].flags = IORESOURCE_MEM;  // Also clears _UNSET flag
113 		if (len <= 0) {
114 			res->mem_resource[i].flags |= IORESOURCE_DISABLED;
115 			return;
116 		}
117 		res->mem_resource[i].start = (unsigned long) mem;
118 		res->mem_resource[i].end = (unsigned long)(mem + len - 1);
119 	}
120 }
121 
122 static unsigned char *
123 pnpbios_parse_allocated_resource_data(unsigned char * p, unsigned char * end, struct pnp_resource_table * res)
124 {
125 	unsigned int len, tag;
126 	int io, size, mask, i;
127 
128 	if (!p)
129 		return NULL;
130 
131 	/* Blank the resource table values */
132 	pnp_init_resource_table(res);
133 
134 	while ((char *)p < (char *)end) {
135 
136 		/* determine the type of tag */
137 		if (p[0] & LARGE_TAG) { /* large tag */
138 			len = (p[2] << 8) | p[1];
139 			tag = p[0];
140 		} else { /* small tag */
141 			len = p[0] & 0x07;
142 			tag = ((p[0]>>3) & 0x0f);
143 		}
144 
145 		switch (tag) {
146 
147 		case LARGE_TAG_MEM:
148 			if (len != 9)
149 				goto len_err;
150 			io = *(short *) &p[4];
151 			size = *(short *) &p[10];
152 			pnpbios_parse_allocated_memresource(res, io, size);
153 			break;
154 
155 		case LARGE_TAG_ANSISTR:
156 			/* ignore this for now */
157 			break;
158 
159 		case LARGE_TAG_VENDOR:
160 			/* do nothing */
161 			break;
162 
163 		case LARGE_TAG_MEM32:
164 			if (len != 17)
165 				goto len_err;
166 			io = *(int *) &p[4];
167 			size = *(int *) &p[16];
168 			pnpbios_parse_allocated_memresource(res, io, size);
169 			break;
170 
171 		case LARGE_TAG_FIXEDMEM32:
172 			if (len != 9)
173 				goto len_err;
174 			io = *(int *) &p[4];
175 			size = *(int *) &p[8];
176 			pnpbios_parse_allocated_memresource(res, io, size);
177 			break;
178 
179 		case SMALL_TAG_IRQ:
180 			if (len < 2 || len > 3)
181 				goto len_err;
182 			io = -1;
183 			mask= p[1] + p[2]*256;
184 			for (i=0;i<16;i++, mask=mask>>1)
185 				if(mask & 0x01) io=i;
186 			pnpbios_parse_allocated_irqresource(res, io);
187 			break;
188 
189 		case SMALL_TAG_DMA:
190 			if (len != 2)
191 				goto len_err;
192 			io = -1;
193 			mask = p[1];
194 			for (i=0;i<8;i++, mask = mask>>1)
195 				if(mask & 0x01) io=i;
196 			pnpbios_parse_allocated_dmaresource(res, io);
197 			break;
198 
199 		case SMALL_TAG_PORT:
200 			if (len != 7)
201 				goto len_err;
202 			io = p[2] + p[3] *256;
203 			size = p[7];
204 			pnpbios_parse_allocated_ioresource(res, io, size);
205 			break;
206 
207 		case SMALL_TAG_VENDOR:
208 			/* do nothing */
209 			break;
210 
211 		case SMALL_TAG_FIXEDPORT:
212 			if (len != 3)
213 				goto len_err;
214 			io = p[1] + p[2] * 256;
215 			size = p[3];
216 			pnpbios_parse_allocated_ioresource(res, io, size);
217 			break;
218 
219 		case SMALL_TAG_END:
220 			p = p + 2;
221         		return (unsigned char *)p;
222 			break;
223 
224 		default: /* an unkown tag */
225 			len_err:
226 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
227 			break;
228 		}
229 
230 		/* continue to the next tag */
231 		if (p[0] & LARGE_TAG)
232 			p += len + 3;
233 		else
234 			p += len + 1;
235 	}
236 
237 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
238 
239 	return NULL;
240 }
241 
242 
243 /*
244  * Resource Configuration Options
245  */
246 
247 static void
248 pnpbios_parse_mem_option(unsigned char *p, int size, struct pnp_option *option)
249 {
250 	struct pnp_mem * mem;
251 	mem = kzalloc(sizeof(struct pnp_mem), GFP_KERNEL);
252 	if (!mem)
253 		return;
254 	mem->min = ((p[5] << 8) | p[4]) << 8;
255 	mem->max = ((p[7] << 8) | p[6]) << 8;
256 	mem->align = (p[9] << 8) | p[8];
257 	mem->size = ((p[11] << 8) | p[10]) << 8;
258 	mem->flags = p[3];
259 	pnp_register_mem_resource(option,mem);
260 	return;
261 }
262 
263 static void
264 pnpbios_parse_mem32_option(unsigned char *p, int size, struct pnp_option *option)
265 {
266 	struct pnp_mem * mem;
267 	mem = kzalloc(sizeof(struct pnp_mem), GFP_KERNEL);
268 	if (!mem)
269 		return;
270 	mem->min = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
271 	mem->max = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
272 	mem->align = (p[15] << 24) | (p[14] << 16) | (p[13] << 8) | p[12];
273 	mem->size = (p[19] << 24) | (p[18] << 16) | (p[17] << 8) | p[16];
274 	mem->flags = p[3];
275 	pnp_register_mem_resource(option,mem);
276 	return;
277 }
278 
279 static void
280 pnpbios_parse_fixed_mem32_option(unsigned char *p, int size, struct pnp_option *option)
281 {
282 	struct pnp_mem * mem;
283 	mem = kzalloc(sizeof(struct pnp_mem), GFP_KERNEL);
284 	if (!mem)
285 		return;
286 	mem->min = mem->max = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
287 	mem->size = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
288 	mem->align = 0;
289 	mem->flags = p[3];
290 	pnp_register_mem_resource(option,mem);
291 	return;
292 }
293 
294 static void
295 pnpbios_parse_irq_option(unsigned char *p, int size, struct pnp_option *option)
296 {
297 	struct pnp_irq * irq;
298 	unsigned long bits;
299 
300 	irq = kzalloc(sizeof(struct pnp_irq), GFP_KERNEL);
301 	if (!irq)
302 		return;
303 	bits = (p[2] << 8) | p[1];
304 	bitmap_copy(irq->map, &bits, 16);
305 	if (size > 2)
306 		irq->flags = p[3];
307 	else
308 		irq->flags = IORESOURCE_IRQ_HIGHEDGE;
309 	pnp_register_irq_resource(option,irq);
310 	return;
311 }
312 
313 static void
314 pnpbios_parse_dma_option(unsigned char *p, int size, struct pnp_option *option)
315 {
316 	struct pnp_dma * dma;
317 	dma = kzalloc(sizeof(struct pnp_dma), GFP_KERNEL);
318 	if (!dma)
319 		return;
320 	dma->map = p[1];
321 	dma->flags = p[2];
322 	pnp_register_dma_resource(option,dma);
323 	return;
324 }
325 
326 static void
327 pnpbios_parse_port_option(unsigned char *p, int size, struct pnp_option *option)
328 {
329 	struct pnp_port * port;
330 	port = kzalloc(sizeof(struct pnp_port), GFP_KERNEL);
331 	if (!port)
332 		return;
333 	port->min = (p[3] << 8) | p[2];
334 	port->max = (p[5] << 8) | p[4];
335 	port->align = p[6];
336 	port->size = p[7];
337 	port->flags = p[1] ? PNP_PORT_FLAG_16BITADDR : 0;
338 	pnp_register_port_resource(option,port);
339 	return;
340 }
341 
342 static void
343 pnpbios_parse_fixed_port_option(unsigned char *p, int size, struct pnp_option *option)
344 {
345 	struct pnp_port * port;
346 	port = kzalloc(sizeof(struct pnp_port), GFP_KERNEL);
347 	if (!port)
348 		return;
349 	port->min = port->max = (p[2] << 8) | p[1];
350 	port->size = p[3];
351 	port->align = 0;
352 	port->flags = PNP_PORT_FLAG_FIXED;
353 	pnp_register_port_resource(option,port);
354 	return;
355 }
356 
357 static unsigned char *
358 pnpbios_parse_resource_option_data(unsigned char * p, unsigned char * end, struct pnp_dev *dev)
359 {
360 	unsigned int len, tag;
361 	int priority = 0;
362 	struct pnp_option *option, *option_independent;
363 
364 	if (!p)
365 		return NULL;
366 
367 	option_independent = option = pnp_register_independent_option(dev);
368 	if (!option)
369 		return NULL;
370 
371 	while ((char *)p < (char *)end) {
372 
373 		/* determine the type of tag */
374 		if (p[0] & LARGE_TAG) { /* large tag */
375 			len = (p[2] << 8) | p[1];
376 			tag = p[0];
377 		} else { /* small tag */
378 			len = p[0] & 0x07;
379 			tag = ((p[0]>>3) & 0x0f);
380 		}
381 
382 		switch (tag) {
383 
384 		case LARGE_TAG_MEM:
385 			if (len != 9)
386 				goto len_err;
387 			pnpbios_parse_mem_option(p, len, option);
388 			break;
389 
390 		case LARGE_TAG_MEM32:
391 			if (len != 17)
392 				goto len_err;
393 			pnpbios_parse_mem32_option(p, len, option);
394 			break;
395 
396 		case LARGE_TAG_FIXEDMEM32:
397 			if (len != 9)
398 				goto len_err;
399 			pnpbios_parse_fixed_mem32_option(p, len, option);
400 			break;
401 
402 		case SMALL_TAG_IRQ:
403 			if (len < 2 || len > 3)
404 				goto len_err;
405 			pnpbios_parse_irq_option(p, len, option);
406 			break;
407 
408 		case SMALL_TAG_DMA:
409 			if (len != 2)
410 				goto len_err;
411 			pnpbios_parse_dma_option(p, len, option);
412 			break;
413 
414 		case SMALL_TAG_PORT:
415 			if (len != 7)
416 				goto len_err;
417 			pnpbios_parse_port_option(p, len, option);
418 			break;
419 
420 		case SMALL_TAG_VENDOR:
421 			/* do nothing */
422 			break;
423 
424 		case SMALL_TAG_FIXEDPORT:
425 			if (len != 3)
426 				goto len_err;
427 			pnpbios_parse_fixed_port_option(p, len, option);
428 			break;
429 
430 		case SMALL_TAG_STARTDEP:
431 			if (len > 1)
432 				goto len_err;
433 			priority = 0x100 | PNP_RES_PRIORITY_ACCEPTABLE;
434 			if (len > 0)
435 				priority = 0x100 | p[1];
436 			option = pnp_register_dependent_option(dev, priority);
437 			if (!option)
438 				return NULL;
439 			break;
440 
441 		case SMALL_TAG_ENDDEP:
442 			if (len != 0)
443 				goto len_err;
444 			if (option_independent == option)
445 				printk(KERN_WARNING "PnPBIOS: Missing SMALL_TAG_STARTDEP tag\n");
446 			option = option_independent;
447 			break;
448 
449 		case SMALL_TAG_END:
450         		return p + 2;
451 
452 		default: /* an unkown tag */
453 			len_err:
454 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
455 			break;
456 		}
457 
458 		/* continue to the next tag */
459 		if (p[0] & LARGE_TAG)
460 			p += len + 3;
461 		else
462 			p += len + 1;
463 	}
464 
465 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
466 
467 	return NULL;
468 }
469 
470 
471 /*
472  * Compatible Device IDs
473  */
474 
475 #define HEX(id,a) hex[((id)>>a) & 15]
476 #define CHAR(id,a) (0x40 + (((id)>>a) & 31))
477 //
478 
479 void pnpid32_to_pnpid(u32 id, char *str)
480 {
481 	const char *hex = "0123456789abcdef";
482 
483 	id = be32_to_cpu(id);
484 	str[0] = CHAR(id, 26);
485 	str[1] = CHAR(id, 21);
486 	str[2] = CHAR(id,16);
487 	str[3] = HEX(id, 12);
488 	str[4] = HEX(id, 8);
489 	str[5] = HEX(id, 4);
490 	str[6] = HEX(id, 0);
491 	str[7] = '\0';
492 
493 	return;
494 }
495 //
496 #undef CHAR
497 #undef HEX
498 
499 static unsigned char *
500 pnpbios_parse_compatible_ids(unsigned char *p, unsigned char *end, struct pnp_dev *dev)
501 {
502 	int len, tag;
503 	char id[8];
504 	struct pnp_id *dev_id;
505 
506 	if (!p)
507 		return NULL;
508 
509 	while ((char *)p < (char *)end) {
510 
511 		/* determine the type of tag */
512 		if (p[0] & LARGE_TAG) { /* large tag */
513 			len = (p[2] << 8) | p[1];
514 			tag = p[0];
515 		} else { /* small tag */
516 			len = p[0] & 0x07;
517 			tag = ((p[0]>>3) & 0x0f);
518 		}
519 
520 		switch (tag) {
521 
522 		case LARGE_TAG_ANSISTR:
523 			strncpy(dev->name, p + 3, len >= PNP_NAME_LEN ? PNP_NAME_LEN - 2 : len);
524 			dev->name[len >= PNP_NAME_LEN ? PNP_NAME_LEN - 1 : len] = '\0';
525 			break;
526 
527 		case SMALL_TAG_COMPATDEVID: /* compatible ID */
528 			if (len != 4)
529 				goto len_err;
530 			dev_id =  kzalloc(sizeof (struct pnp_id), GFP_KERNEL);
531 			if (!dev_id)
532 				return NULL;
533 			pnpid32_to_pnpid(p[1] | p[2] << 8 | p[3] << 16 | p[4] << 24,id);
534 			memcpy(&dev_id->id, id, 7);
535 			pnp_add_id(dev_id, dev);
536 			break;
537 
538 		case SMALL_TAG_END:
539 			p = p + 2;
540         		return (unsigned char *)p;
541 			break;
542 
543 		default: /* an unkown tag */
544 			len_err:
545 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
546 			break;
547 		}
548 
549 		/* continue to the next tag */
550 		if (p[0] & LARGE_TAG)
551 			p += len + 3;
552 		else
553 			p += len + 1;
554 	}
555 
556 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
557 
558 	return NULL;
559 }
560 
561 
562 /*
563  * Allocated Resource Encoding
564  */
565 
566 static void pnpbios_encode_mem(unsigned char *p, struct resource * res)
567 {
568 	unsigned long base = res->start;
569 	unsigned long len = res->end - res->start + 1;
570 	p[4] = (base >> 8) & 0xff;
571 	p[5] = ((base >> 8) >> 8) & 0xff;
572 	p[6] = (base >> 8) & 0xff;
573 	p[7] = ((base >> 8) >> 8) & 0xff;
574 	p[10] = (len >> 8) & 0xff;
575 	p[11] = ((len >> 8) >> 8) & 0xff;
576 	return;
577 }
578 
579 static void pnpbios_encode_mem32(unsigned char *p, struct resource * res)
580 {
581 	unsigned long base = res->start;
582 	unsigned long len = res->end - res->start + 1;
583 	p[4] = base & 0xff;
584 	p[5] = (base >> 8) & 0xff;
585 	p[6] = (base >> 16) & 0xff;
586 	p[7] = (base >> 24) & 0xff;
587 	p[8] = base & 0xff;
588 	p[9] = (base >> 8) & 0xff;
589 	p[10] = (base >> 16) & 0xff;
590 	p[11] = (base >> 24) & 0xff;
591 	p[16] = len & 0xff;
592 	p[17] = (len >> 8) & 0xff;
593 	p[18] = (len >> 16) & 0xff;
594 	p[19] = (len >> 24) & 0xff;
595 	return;
596 }
597 
598 static void pnpbios_encode_fixed_mem32(unsigned char *p, struct resource * res)
599 {	unsigned long base = res->start;
600 	unsigned long len = res->end - res->start + 1;
601 	p[4] = base & 0xff;
602 	p[5] = (base >> 8) & 0xff;
603 	p[6] = (base >> 16) & 0xff;
604 	p[7] = (base >> 24) & 0xff;
605 	p[8] = len & 0xff;
606 	p[9] = (len >> 8) & 0xff;
607 	p[10] = (len >> 16) & 0xff;
608 	p[11] = (len >> 24) & 0xff;
609 	return;
610 }
611 
612 static void pnpbios_encode_irq(unsigned char *p, struct resource * res)
613 {
614 	unsigned long map = 0;
615 	map = 1 << res->start;
616 	p[1] = map & 0xff;
617 	p[2] = (map >> 8) & 0xff;
618 	return;
619 }
620 
621 static void pnpbios_encode_dma(unsigned char *p, struct resource * res)
622 {
623 	unsigned long map = 0;
624 	map = 1 << res->start;
625 	p[1] = map & 0xff;
626 	return;
627 }
628 
629 static void pnpbios_encode_port(unsigned char *p, struct resource * res)
630 {
631 	unsigned long base = res->start;
632 	unsigned long len = res->end - res->start + 1;
633 	p[2] = base & 0xff;
634 	p[3] = (base >> 8) & 0xff;
635 	p[4] = base & 0xff;
636 	p[5] = (base >> 8) & 0xff;
637 	p[7] = len & 0xff;
638 	return;
639 }
640 
641 static void pnpbios_encode_fixed_port(unsigned char *p, struct resource * res)
642 {
643 	unsigned long base = res->start;
644 	unsigned long len = res->end - res->start + 1;
645 	p[1] = base & 0xff;
646 	p[2] = (base >> 8) & 0xff;
647 	p[3] = len & 0xff;
648 	return;
649 }
650 
651 static unsigned char *
652 pnpbios_encode_allocated_resource_data(unsigned char * p, unsigned char * end, struct pnp_resource_table * res)
653 {
654 	unsigned int len, tag;
655 	int port = 0, irq = 0, dma = 0, mem = 0;
656 
657 	if (!p)
658 		return NULL;
659 
660 	while ((char *)p < (char *)end) {
661 
662 		/* determine the type of tag */
663 		if (p[0] & LARGE_TAG) { /* large tag */
664 			len = (p[2] << 8) | p[1];
665 			tag = p[0];
666 		} else { /* small tag */
667 			len = p[0] & 0x07;
668 			tag = ((p[0]>>3) & 0x0f);
669 		}
670 
671 		switch (tag) {
672 
673 		case LARGE_TAG_MEM:
674 			if (len != 9)
675 				goto len_err;
676 			pnpbios_encode_mem(p, &res->mem_resource[mem]);
677 			mem++;
678 			break;
679 
680 		case LARGE_TAG_MEM32:
681 			if (len != 17)
682 				goto len_err;
683 			pnpbios_encode_mem32(p, &res->mem_resource[mem]);
684 			mem++;
685 			break;
686 
687 		case LARGE_TAG_FIXEDMEM32:
688 			if (len != 9)
689 				goto len_err;
690 			pnpbios_encode_fixed_mem32(p, &res->mem_resource[mem]);
691 			mem++;
692 			break;
693 
694 		case SMALL_TAG_IRQ:
695 			if (len < 2 || len > 3)
696 				goto len_err;
697 			pnpbios_encode_irq(p, &res->irq_resource[irq]);
698 			irq++;
699 			break;
700 
701 		case SMALL_TAG_DMA:
702 			if (len != 2)
703 				goto len_err;
704 			pnpbios_encode_dma(p, &res->dma_resource[dma]);
705 			dma++;
706 			break;
707 
708 		case SMALL_TAG_PORT:
709 			if (len != 7)
710 				goto len_err;
711 			pnpbios_encode_port(p, &res->port_resource[port]);
712 			port++;
713 			break;
714 
715 		case SMALL_TAG_VENDOR:
716 			/* do nothing */
717 			break;
718 
719 		case SMALL_TAG_FIXEDPORT:
720 			if (len != 3)
721 				goto len_err;
722 			pnpbios_encode_fixed_port(p, &res->port_resource[port]);
723 			port++;
724 			break;
725 
726 		case SMALL_TAG_END:
727 			p = p + 2;
728         		return (unsigned char *)p;
729 			break;
730 
731 		default: /* an unkown tag */
732 			len_err:
733 			printk(KERN_ERR "PnPBIOS: Unknown tag '0x%x', length '%d'.\n", tag, len);
734 			break;
735 		}
736 
737 		/* continue to the next tag */
738 		if (p[0] & LARGE_TAG)
739 			p += len + 3;
740 		else
741 			p += len + 1;
742 	}
743 
744 	printk(KERN_ERR "PnPBIOS: Resource structure does not contain an end tag.\n");
745 
746 	return NULL;
747 }
748 
749 
750 /*
751  * Core Parsing Functions
752  */
753 
754 int
755 pnpbios_parse_data_stream(struct pnp_dev *dev, struct pnp_bios_node * node)
756 {
757 	unsigned char * p = (char *)node->data;
758 	unsigned char * end = (char *)(node->data + node->size);
759 	p = pnpbios_parse_allocated_resource_data(p,end,&dev->res);
760 	if (!p)
761 		return -EIO;
762 	p = pnpbios_parse_resource_option_data(p,end,dev);
763 	if (!p)
764 		return -EIO;
765 	p = pnpbios_parse_compatible_ids(p,end,dev);
766 	if (!p)
767 		return -EIO;
768 	return 0;
769 }
770 
771 int
772 pnpbios_read_resources_from_node(struct pnp_resource_table *res,
773 				 struct pnp_bios_node * node)
774 {
775 	unsigned char * p = (char *)node->data;
776 	unsigned char * end = (char *)(node->data + node->size);
777 	p = pnpbios_parse_allocated_resource_data(p,end,res);
778 	if (!p)
779 		return -EIO;
780 	return 0;
781 }
782 
783 int
784 pnpbios_write_resources_to_node(struct pnp_resource_table *res,
785 				struct pnp_bios_node * node)
786 {
787 	unsigned char * p = (char *)node->data;
788 	unsigned char * end = (char *)(node->data + node->size);
789 	p = pnpbios_encode_allocated_resource_data(p,end,res);
790 	if (!p)
791 		return -EIO;
792 	return 0;
793 }
794