xref: /linux/drivers/pnp/pnpbios/rsparser.c (revision b8e85e6f3a09fc56b0ff574887798962ef8a8f80)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * rsparser.c - parses and encodes pnpbios resource data streams
4  */
5 
6 #include <linux/ctype.h>
7 #include <linux/pnp.h>
8 #include <linux/string.h>
9 
10 #ifdef CONFIG_PCI
11 #include <linux/pci.h>
12 #else
13 inline void pcibios_penalize_isa_irq(int irq, int active)
14 {
15 }
16 #endif				/* CONFIG_PCI */
17 
18 #include "../base.h"
19 #include "pnpbios.h"
20 
21 /* standard resource tags */
22 #define SMALL_TAG_PNPVERNO		0x01
23 #define SMALL_TAG_LOGDEVID		0x02
24 #define SMALL_TAG_COMPATDEVID		0x03
25 #define SMALL_TAG_IRQ			0x04
26 #define SMALL_TAG_DMA			0x05
27 #define SMALL_TAG_STARTDEP		0x06
28 #define SMALL_TAG_ENDDEP		0x07
29 #define SMALL_TAG_PORT			0x08
30 #define SMALL_TAG_FIXEDPORT		0x09
31 #define SMALL_TAG_VENDOR		0x0e
32 #define SMALL_TAG_END			0x0f
33 #define LARGE_TAG			0x80
34 #define LARGE_TAG_MEM			0x81
35 #define LARGE_TAG_ANSISTR		0x82
36 #define LARGE_TAG_UNICODESTR		0x83
37 #define LARGE_TAG_VENDOR		0x84
38 #define LARGE_TAG_MEM32			0x85
39 #define LARGE_TAG_FIXEDMEM32		0x86
40 
41 /*
42  * Resource Data Stream Format:
43  *
44  * Allocated Resources (required)
45  * end tag ->
46  * Resource Configuration Options (optional)
47  * end tag ->
48  * Compitable Device IDs (optional)
49  * final end tag ->
50  */
51 
52 /*
53  * Allocated Resources
54  */
55 
56 static void pnpbios_parse_allocated_ioresource(struct pnp_dev *dev,
57 					       int start, int len)
58 {
59 	int flags = 0;
60 	int end = start + len - 1;
61 
62 	if (len <= 0 || end >= 0x10003)
63 		flags |= IORESOURCE_DISABLED;
64 
65 	pnp_add_io_resource(dev, start, end, flags);
66 }
67 
68 static void pnpbios_parse_allocated_memresource(struct pnp_dev *dev,
69 						int start, int len)
70 {
71 	int flags = 0;
72 	int end = start + len - 1;
73 
74 	if (len <= 0)
75 		flags |= IORESOURCE_DISABLED;
76 
77 	pnp_add_mem_resource(dev, start, end, flags);
78 }
79 
80 static unsigned char *pnpbios_parse_allocated_resource_data(struct pnp_dev *dev,
81 							    unsigned char *p,
82 							    unsigned char *end)
83 {
84 	unsigned int len, tag;
85 	int io, size, mask, i, flags;
86 
87 	if (!p)
88 		return NULL;
89 
90 	pnp_dbg(&dev->dev, "parse allocated resources\n");
91 
92 	pnp_init_resources(dev);
93 
94 	while ((char *)p < (char *)end) {
95 
96 		/* determine the type of tag */
97 		if (p[0] & LARGE_TAG) {	/* large tag */
98 			len = (p[2] << 8) | p[1];
99 			tag = p[0];
100 		} else {	/* small tag */
101 			len = p[0] & 0x07;
102 			tag = ((p[0] >> 3) & 0x0f);
103 		}
104 
105 		switch (tag) {
106 
107 		case LARGE_TAG_MEM:
108 			if (len != 9)
109 				goto len_err;
110 			io = *(short *)&p[4];
111 			size = *(short *)&p[10];
112 			pnpbios_parse_allocated_memresource(dev, io, size);
113 			break;
114 
115 		case LARGE_TAG_ANSISTR:
116 			/* ignore this for now */
117 			break;
118 
119 		case LARGE_TAG_VENDOR:
120 			/* do nothing */
121 			break;
122 
123 		case LARGE_TAG_MEM32:
124 			if (len != 17)
125 				goto len_err;
126 			io = *(int *)&p[4];
127 			size = *(int *)&p[16];
128 			pnpbios_parse_allocated_memresource(dev, io, size);
129 			break;
130 
131 		case LARGE_TAG_FIXEDMEM32:
132 			if (len != 9)
133 				goto len_err;
134 			io = *(int *)&p[4];
135 			size = *(int *)&p[8];
136 			pnpbios_parse_allocated_memresource(dev, io, size);
137 			break;
138 
139 		case SMALL_TAG_IRQ:
140 			if (len < 2 || len > 3)
141 				goto len_err;
142 			flags = 0;
143 			io = -1;
144 			mask = p[1] + p[2] * 256;
145 			for (i = 0; i < 16; i++, mask = mask >> 1)
146 				if (mask & 0x01)
147 					io = i;
148 			if (io != -1)
149 				pcibios_penalize_isa_irq(io, 1);
150 			else
151 				flags = IORESOURCE_DISABLED;
152 			pnp_add_irq_resource(dev, io, flags);
153 			break;
154 
155 		case SMALL_TAG_DMA:
156 			if (len != 2)
157 				goto len_err;
158 			flags = 0;
159 			io = -1;
160 			mask = p[1];
161 			for (i = 0; i < 8; i++, mask = mask >> 1)
162 				if (mask & 0x01)
163 					io = i;
164 			if (io == -1)
165 				flags = IORESOURCE_DISABLED;
166 			pnp_add_dma_resource(dev, io, flags);
167 			break;
168 
169 		case SMALL_TAG_PORT:
170 			if (len != 7)
171 				goto len_err;
172 			io = p[2] + p[3] * 256;
173 			size = p[7];
174 			pnpbios_parse_allocated_ioresource(dev, io, size);
175 			break;
176 
177 		case SMALL_TAG_VENDOR:
178 			/* do nothing */
179 			break;
180 
181 		case SMALL_TAG_FIXEDPORT:
182 			if (len != 3)
183 				goto len_err;
184 			io = p[1] + p[2] * 256;
185 			size = p[3];
186 			pnpbios_parse_allocated_ioresource(dev, io, size);
187 			break;
188 
189 		case SMALL_TAG_END:
190 			p = p + 2;
191 			return (unsigned char *)p;
192 			break;
193 
194 		default:	/* an unknown tag */
195 len_err:
196 			dev_err(&dev->dev, "unknown tag %#x length %d\n",
197 				tag, len);
198 			break;
199 		}
200 
201 		/* continue to the next tag */
202 		if (p[0] & LARGE_TAG)
203 			p += len + 3;
204 		else
205 			p += len + 1;
206 	}
207 
208 	dev_err(&dev->dev, "no end tag in resource structure\n");
209 
210 	return NULL;
211 }
212 
213 /*
214  * Resource Configuration Options
215  */
216 
217 static __init void pnpbios_parse_mem_option(struct pnp_dev *dev,
218 					    unsigned char *p, int size,
219 					    unsigned int option_flags)
220 {
221 	resource_size_t min, max, align, len;
222 	unsigned char flags;
223 
224 	min = ((p[5] << 8) | p[4]) << 8;
225 	max = ((p[7] << 8) | p[6]) << 8;
226 	align = (p[9] << 8) | p[8];
227 	len = ((p[11] << 8) | p[10]) << 8;
228 	flags = p[3];
229 	pnp_register_mem_resource(dev, option_flags, min, max, align, len,
230 				  flags);
231 }
232 
233 static __init void pnpbios_parse_mem32_option(struct pnp_dev *dev,
234 					      unsigned char *p, int size,
235 					      unsigned int option_flags)
236 {
237 	resource_size_t min, max, align, len;
238 	unsigned char flags;
239 
240 	min = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
241 	max = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
242 	align = (p[15] << 24) | (p[14] << 16) | (p[13] << 8) | p[12];
243 	len = (p[19] << 24) | (p[18] << 16) | (p[17] << 8) | p[16];
244 	flags = p[3];
245 	pnp_register_mem_resource(dev, option_flags, min, max, align, len,
246 				  flags);
247 }
248 
249 static __init void pnpbios_parse_fixed_mem32_option(struct pnp_dev *dev,
250 						    unsigned char *p, int size,
251 						    unsigned int option_flags)
252 {
253 	resource_size_t base, len;
254 	unsigned char flags;
255 
256 	base = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
257 	len = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
258 	flags = p[3];
259 	pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags);
260 }
261 
262 static __init void pnpbios_parse_irq_option(struct pnp_dev *dev,
263 					    unsigned char *p, int size,
264 					    unsigned int option_flags)
265 {
266 	unsigned long bits;
267 	pnp_irq_mask_t map;
268 	unsigned char flags = IORESOURCE_IRQ_HIGHEDGE;
269 
270 	bits = (p[2] << 8) | p[1];
271 
272 	bitmap_zero(map.bits, PNP_IRQ_NR);
273 	bitmap_copy(map.bits, &bits, 16);
274 
275 	if (size > 2)
276 		flags = p[3];
277 
278 	pnp_register_irq_resource(dev, option_flags, &map, flags);
279 }
280 
281 static __init void pnpbios_parse_dma_option(struct pnp_dev *dev,
282 					    unsigned char *p, int size,
283 					    unsigned int option_flags)
284 {
285 	pnp_register_dma_resource(dev, option_flags, p[1], p[2]);
286 }
287 
288 static __init void pnpbios_parse_port_option(struct pnp_dev *dev,
289 					     unsigned char *p, int size,
290 					     unsigned int option_flags)
291 {
292 	resource_size_t min, max, align, len;
293 	unsigned char flags;
294 
295 	min = (p[3] << 8) | p[2];
296 	max = (p[5] << 8) | p[4];
297 	align = p[6];
298 	len = p[7];
299 	flags = p[1] ? IORESOURCE_IO_16BIT_ADDR : 0;
300 	pnp_register_port_resource(dev, option_flags, min, max, align, len,
301 				   flags);
302 }
303 
304 static __init void pnpbios_parse_fixed_port_option(struct pnp_dev *dev,
305 						   unsigned char *p, int size,
306 						   unsigned int option_flags)
307 {
308 	resource_size_t base, len;
309 
310 	base = (p[2] << 8) | p[1];
311 	len = p[3];
312 	pnp_register_port_resource(dev, option_flags, base, base, 0, len,
313 				   IORESOURCE_IO_FIXED);
314 }
315 
316 static __init unsigned char *
317 pnpbios_parse_resource_option_data(unsigned char *p, unsigned char *end,
318 				   struct pnp_dev *dev)
319 {
320 	unsigned int len, tag;
321 	int priority;
322 	unsigned int option_flags;
323 
324 	if (!p)
325 		return NULL;
326 
327 	pnp_dbg(&dev->dev, "parse resource options\n");
328 	option_flags = 0;
329 	while ((char *)p < (char *)end) {
330 
331 		/* determine the type of tag */
332 		if (p[0] & LARGE_TAG) {	/* large tag */
333 			len = (p[2] << 8) | p[1];
334 			tag = p[0];
335 		} else {	/* small tag */
336 			len = p[0] & 0x07;
337 			tag = ((p[0] >> 3) & 0x0f);
338 		}
339 
340 		switch (tag) {
341 
342 		case LARGE_TAG_MEM:
343 			if (len != 9)
344 				goto len_err;
345 			pnpbios_parse_mem_option(dev, p, len, option_flags);
346 			break;
347 
348 		case LARGE_TAG_MEM32:
349 			if (len != 17)
350 				goto len_err;
351 			pnpbios_parse_mem32_option(dev, p, len, option_flags);
352 			break;
353 
354 		case LARGE_TAG_FIXEDMEM32:
355 			if (len != 9)
356 				goto len_err;
357 			pnpbios_parse_fixed_mem32_option(dev, p, len,
358 							 option_flags);
359 			break;
360 
361 		case SMALL_TAG_IRQ:
362 			if (len < 2 || len > 3)
363 				goto len_err;
364 			pnpbios_parse_irq_option(dev, p, len, option_flags);
365 			break;
366 
367 		case SMALL_TAG_DMA:
368 			if (len != 2)
369 				goto len_err;
370 			pnpbios_parse_dma_option(dev, p, len, option_flags);
371 			break;
372 
373 		case SMALL_TAG_PORT:
374 			if (len != 7)
375 				goto len_err;
376 			pnpbios_parse_port_option(dev, p, len, option_flags);
377 			break;
378 
379 		case SMALL_TAG_VENDOR:
380 			/* do nothing */
381 			break;
382 
383 		case SMALL_TAG_FIXEDPORT:
384 			if (len != 3)
385 				goto len_err;
386 			pnpbios_parse_fixed_port_option(dev, p, len,
387 							option_flags);
388 			break;
389 
390 		case SMALL_TAG_STARTDEP:
391 			if (len > 1)
392 				goto len_err;
393 			priority = PNP_RES_PRIORITY_ACCEPTABLE;
394 			if (len > 0)
395 				priority = p[1];
396 			option_flags = pnp_new_dependent_set(dev, priority);
397 			break;
398 
399 		case SMALL_TAG_ENDDEP:
400 			if (len != 0)
401 				goto len_err;
402 			option_flags = 0;
403 			break;
404 
405 		case SMALL_TAG_END:
406 			return p + 2;
407 
408 		default:	/* an unknown tag */
409 len_err:
410 			dev_err(&dev->dev, "unknown tag %#x length %d\n",
411 				tag, len);
412 			break;
413 		}
414 
415 		/* continue to the next tag */
416 		if (p[0] & LARGE_TAG)
417 			p += len + 3;
418 		else
419 			p += len + 1;
420 	}
421 
422 	dev_err(&dev->dev, "no end tag in resource structure\n");
423 
424 	return NULL;
425 }
426 
427 /*
428  * Compatible Device IDs
429  */
430 
431 static unsigned char *pnpbios_parse_compatible_ids(unsigned char *p,
432 						   unsigned char *end,
433 						   struct pnp_dev *dev)
434 {
435 	int len, tag;
436 	u32 eisa_id;
437 	char id[8];
438 	struct pnp_id *dev_id;
439 
440 	if (!p)
441 		return NULL;
442 
443 	while ((char *)p < (char *)end) {
444 
445 		/* determine the type of tag */
446 		if (p[0] & LARGE_TAG) {	/* large tag */
447 			len = (p[2] << 8) | p[1];
448 			tag = p[0];
449 		} else {	/* small tag */
450 			len = p[0] & 0x07;
451 			tag = ((p[0] >> 3) & 0x0f);
452 		}
453 
454 		switch (tag) {
455 
456 		case LARGE_TAG_ANSISTR:
457 			memcpy(dev->name, p + 3,
458 			       len >= PNP_NAME_LEN ? PNP_NAME_LEN - 2 : len);
459 			dev->name[len >=
460 				  PNP_NAME_LEN ? PNP_NAME_LEN - 1 : len] = '\0';
461 			break;
462 
463 		case SMALL_TAG_COMPATDEVID:	/* compatible ID */
464 			if (len != 4)
465 				goto len_err;
466 			eisa_id = p[1] | p[2] << 8 | p[3] << 16 | p[4] << 24;
467 			pnp_eisa_id_to_string(eisa_id & PNP_EISA_ID_MASK, id);
468 			dev_id = pnp_add_id(dev, id);
469 			if (!dev_id)
470 				return NULL;
471 			break;
472 
473 		case SMALL_TAG_END:
474 			p = p + 2;
475 			return (unsigned char *)p;
476 			break;
477 
478 		default:	/* an unknown tag */
479 len_err:
480 			dev_err(&dev->dev, "unknown tag %#x length %d\n",
481 				tag, len);
482 			break;
483 		}
484 
485 		/* continue to the next tag */
486 		if (p[0] & LARGE_TAG)
487 			p += len + 3;
488 		else
489 			p += len + 1;
490 	}
491 
492 	dev_err(&dev->dev, "no end tag in resource structure\n");
493 
494 	return NULL;
495 }
496 
497 /*
498  * Allocated Resource Encoding
499  */
500 
501 static void pnpbios_encode_mem(struct pnp_dev *dev, unsigned char *p,
502 			       struct resource *res)
503 {
504 	unsigned long base;
505 	unsigned long len;
506 
507 	if (pnp_resource_enabled(res)) {
508 		base = res->start;
509 		len = resource_size(res);
510 	} else {
511 		base = 0;
512 		len = 0;
513 	}
514 
515 	p[4] = (base >> 8) & 0xff;
516 	p[5] = ((base >> 8) >> 8) & 0xff;
517 	p[6] = (base >> 8) & 0xff;
518 	p[7] = ((base >> 8) >> 8) & 0xff;
519 	p[10] = (len >> 8) & 0xff;
520 	p[11] = ((len >> 8) >> 8) & 0xff;
521 
522 	pnp_dbg(&dev->dev, "  encode mem %#lx-%#lx\n", base, base + len - 1);
523 }
524 
525 static void pnpbios_encode_mem32(struct pnp_dev *dev, unsigned char *p,
526 				 struct resource *res)
527 {
528 	unsigned long base;
529 	unsigned long len;
530 
531 	if (pnp_resource_enabled(res)) {
532 		base = res->start;
533 		len = resource_size(res);
534 	} else {
535 		base = 0;
536 		len = 0;
537 	}
538 
539 	p[4] = base & 0xff;
540 	p[5] = (base >> 8) & 0xff;
541 	p[6] = (base >> 16) & 0xff;
542 	p[7] = (base >> 24) & 0xff;
543 	p[8] = base & 0xff;
544 	p[9] = (base >> 8) & 0xff;
545 	p[10] = (base >> 16) & 0xff;
546 	p[11] = (base >> 24) & 0xff;
547 	p[16] = len & 0xff;
548 	p[17] = (len >> 8) & 0xff;
549 	p[18] = (len >> 16) & 0xff;
550 	p[19] = (len >> 24) & 0xff;
551 
552 	pnp_dbg(&dev->dev, "  encode mem32 %#lx-%#lx\n", base, base + len - 1);
553 }
554 
555 static void pnpbios_encode_fixed_mem32(struct pnp_dev *dev, unsigned char *p,
556 				       struct resource *res)
557 {
558 	unsigned long base;
559 	unsigned long len;
560 
561 	if (pnp_resource_enabled(res)) {
562 		base = res->start;
563 		len = resource_size(res);
564 	} else {
565 		base = 0;
566 		len = 0;
567 	}
568 
569 	p[4] = base & 0xff;
570 	p[5] = (base >> 8) & 0xff;
571 	p[6] = (base >> 16) & 0xff;
572 	p[7] = (base >> 24) & 0xff;
573 	p[8] = len & 0xff;
574 	p[9] = (len >> 8) & 0xff;
575 	p[10] = (len >> 16) & 0xff;
576 	p[11] = (len >> 24) & 0xff;
577 
578 	pnp_dbg(&dev->dev, "  encode fixed_mem32 %#lx-%#lx\n", base,
579 		base + len - 1);
580 }
581 
582 static void pnpbios_encode_irq(struct pnp_dev *dev, unsigned char *p,
583 			       struct resource *res)
584 {
585 	unsigned long map;
586 
587 	if (pnp_resource_enabled(res))
588 		map = 1 << res->start;
589 	else
590 		map = 0;
591 
592 	p[1] = map & 0xff;
593 	p[2] = (map >> 8) & 0xff;
594 
595 	pnp_dbg(&dev->dev, "  encode irq mask %#lx\n", map);
596 }
597 
598 static void pnpbios_encode_dma(struct pnp_dev *dev, unsigned char *p,
599 			       struct resource *res)
600 {
601 	unsigned long map;
602 
603 	if (pnp_resource_enabled(res))
604 		map = 1 << res->start;
605 	else
606 		map = 0;
607 
608 	p[1] = map & 0xff;
609 
610 	pnp_dbg(&dev->dev, "  encode dma mask %#lx\n", map);
611 }
612 
613 static void pnpbios_encode_port(struct pnp_dev *dev, unsigned char *p,
614 				struct resource *res)
615 {
616 	unsigned long base;
617 	unsigned long len;
618 
619 	if (pnp_resource_enabled(res)) {
620 		base = res->start;
621 		len = resource_size(res);
622 	} else {
623 		base = 0;
624 		len = 0;
625 	}
626 
627 	p[2] = base & 0xff;
628 	p[3] = (base >> 8) & 0xff;
629 	p[4] = base & 0xff;
630 	p[5] = (base >> 8) & 0xff;
631 	p[7] = len & 0xff;
632 
633 	pnp_dbg(&dev->dev, "  encode io %#lx-%#lx\n", base, base + len - 1);
634 }
635 
636 static void pnpbios_encode_fixed_port(struct pnp_dev *dev, unsigned char *p,
637 				      struct resource *res)
638 {
639 	unsigned long base = res->start;
640 	unsigned long len = resource_size(res);
641 
642 	if (pnp_resource_enabled(res)) {
643 		base = res->start;
644 		len = resource_size(res);
645 	} else {
646 		base = 0;
647 		len = 0;
648 	}
649 
650 	p[1] = base & 0xff;
651 	p[2] = (base >> 8) & 0xff;
652 	p[3] = len & 0xff;
653 
654 	pnp_dbg(&dev->dev, "  encode fixed_io %#lx-%#lx\n", base,
655 		base + len - 1);
656 }
657 
658 static unsigned char *pnpbios_encode_allocated_resource_data(struct pnp_dev
659 								*dev,
660 							     unsigned char *p,
661 							     unsigned char *end)
662 {
663 	unsigned int len, tag;
664 	int port = 0, irq = 0, dma = 0, mem = 0;
665 
666 	if (!p)
667 		return NULL;
668 
669 	while ((char *)p < (char *)end) {
670 
671 		/* determine the type of tag */
672 		if (p[0] & LARGE_TAG) {	/* large tag */
673 			len = (p[2] << 8) | p[1];
674 			tag = p[0];
675 		} else {	/* small tag */
676 			len = p[0] & 0x07;
677 			tag = ((p[0] >> 3) & 0x0f);
678 		}
679 
680 		switch (tag) {
681 
682 		case LARGE_TAG_MEM:
683 			if (len != 9)
684 				goto len_err;
685 			pnpbios_encode_mem(dev, p,
686 				pnp_get_resource(dev, IORESOURCE_MEM, mem));
687 			mem++;
688 			break;
689 
690 		case LARGE_TAG_MEM32:
691 			if (len != 17)
692 				goto len_err;
693 			pnpbios_encode_mem32(dev, p,
694 				pnp_get_resource(dev, IORESOURCE_MEM, mem));
695 			mem++;
696 			break;
697 
698 		case LARGE_TAG_FIXEDMEM32:
699 			if (len != 9)
700 				goto len_err;
701 			pnpbios_encode_fixed_mem32(dev, p,
702 				pnp_get_resource(dev, IORESOURCE_MEM, mem));
703 			mem++;
704 			break;
705 
706 		case SMALL_TAG_IRQ:
707 			if (len < 2 || len > 3)
708 				goto len_err;
709 			pnpbios_encode_irq(dev, p,
710 				pnp_get_resource(dev, IORESOURCE_IRQ, irq));
711 			irq++;
712 			break;
713 
714 		case SMALL_TAG_DMA:
715 			if (len != 2)
716 				goto len_err;
717 			pnpbios_encode_dma(dev, p,
718 				pnp_get_resource(dev, IORESOURCE_DMA, dma));
719 			dma++;
720 			break;
721 
722 		case SMALL_TAG_PORT:
723 			if (len != 7)
724 				goto len_err;
725 			pnpbios_encode_port(dev, p,
726 				pnp_get_resource(dev, IORESOURCE_IO, port));
727 			port++;
728 			break;
729 
730 		case SMALL_TAG_VENDOR:
731 			/* do nothing */
732 			break;
733 
734 		case SMALL_TAG_FIXEDPORT:
735 			if (len != 3)
736 				goto len_err;
737 			pnpbios_encode_fixed_port(dev, p,
738 				pnp_get_resource(dev, IORESOURCE_IO, port));
739 			port++;
740 			break;
741 
742 		case SMALL_TAG_END:
743 			p = p + 2;
744 			return (unsigned char *)p;
745 			break;
746 
747 		default:	/* an unknown tag */
748 len_err:
749 			dev_err(&dev->dev, "unknown tag %#x length %d\n",
750 				tag, len);
751 			break;
752 		}
753 
754 		/* continue to the next tag */
755 		if (p[0] & LARGE_TAG)
756 			p += len + 3;
757 		else
758 			p += len + 1;
759 	}
760 
761 	dev_err(&dev->dev, "no end tag in resource structure\n");
762 
763 	return NULL;
764 }
765 
766 /*
767  * Core Parsing Functions
768  */
769 
770 int __init pnpbios_parse_data_stream(struct pnp_dev *dev,
771 					struct pnp_bios_node *node)
772 {
773 	unsigned char *p = (char *)node->data;
774 	unsigned char *end = (char *)(node->data + node->size);
775 
776 	p = pnpbios_parse_allocated_resource_data(dev, p, end);
777 	if (!p)
778 		return -EIO;
779 	p = pnpbios_parse_resource_option_data(p, end, dev);
780 	if (!p)
781 		return -EIO;
782 	p = pnpbios_parse_compatible_ids(p, end, dev);
783 	if (!p)
784 		return -EIO;
785 	return 0;
786 }
787 
788 int pnpbios_read_resources_from_node(struct pnp_dev *dev,
789 				     struct pnp_bios_node *node)
790 {
791 	unsigned char *p = (char *)node->data;
792 	unsigned char *end = (char *)(node->data + node->size);
793 
794 	p = pnpbios_parse_allocated_resource_data(dev, p, end);
795 	if (!p)
796 		return -EIO;
797 	return 0;
798 }
799 
800 int pnpbios_write_resources_to_node(struct pnp_dev *dev,
801 				    struct pnp_bios_node *node)
802 {
803 	unsigned char *p = (char *)node->data;
804 	unsigned char *end = (char *)(node->data + node->size);
805 
806 	p = pnpbios_encode_allocated_resource_data(dev, p, end);
807 	if (!p)
808 		return -EIO;
809 	return 0;
810 }
811