xref: /linux/drivers/pnp/resource.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * resource.c - Contains functions for registering and analyzing resource information
4  *
5  * based on isapnp.c resource management (c) Jaroslav Kysela <perex@perex.cz>
6  * Copyright 2003 Adam Belay <ambx1@neo.rr.com>
7  * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
8  *	Bjorn Helgaas <bjorn.helgaas@hp.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/errno.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel.h>
16 #include <asm/io.h>
17 #include <asm/dma.h>
18 #include <asm/irq.h>
19 #include <linux/pci.h>
20 #include <linux/ioport.h>
21 #include <linux/init.h>
22 
23 #include <linux/pnp.h>
24 #include "base.h"
25 
26 static int pnp_reserve_irq[16] = {[0 ... 15] = -1 };	/* reserve (don't use) some IRQ */
27 static int pnp_reserve_dma[8] = {[0 ... 7] = -1 };	/* reserve (don't use) some DMA */
28 static int pnp_reserve_io[16] = {[0 ... 15] = -1 };	/* reserve (don't use) some I/O region */
29 static int pnp_reserve_mem[16] = {[0 ... 15] = -1 };	/* reserve (don't use) some memory region */
30 
31 /*
32  * option registration
33  */
34 
35 static struct pnp_option *pnp_build_option(struct pnp_dev *dev, unsigned long type,
36 				    unsigned int option_flags)
37 {
38 	struct pnp_option *option;
39 
40 	option = kzalloc(sizeof(struct pnp_option), GFP_KERNEL);
41 	if (!option)
42 		return NULL;
43 
44 	option->flags = option_flags;
45 	option->type = type;
46 
47 	list_add_tail(&option->list, &dev->options);
48 	return option;
49 }
50 
51 int pnp_register_irq_resource(struct pnp_dev *dev, unsigned int option_flags,
52 			      pnp_irq_mask_t *map, unsigned char flags)
53 {
54 	struct pnp_option *option;
55 	struct pnp_irq *irq;
56 
57 	option = pnp_build_option(dev, IORESOURCE_IRQ, option_flags);
58 	if (!option)
59 		return -ENOMEM;
60 
61 	irq = &option->u.irq;
62 	irq->map = *map;
63 	irq->flags = flags;
64 
65 #ifdef CONFIG_PCI
66 	{
67 		int i;
68 
69 		for (i = 0; i < 16; i++)
70 			if (test_bit(i, irq->map.bits))
71 				pcibios_penalize_isa_irq(i, 0);
72 	}
73 #endif
74 
75 	dbg_pnp_show_option(dev, option);
76 	return 0;
77 }
78 
79 int pnp_register_dma_resource(struct pnp_dev *dev, unsigned int option_flags,
80 			      unsigned char map, unsigned char flags)
81 {
82 	struct pnp_option *option;
83 	struct pnp_dma *dma;
84 
85 	option = pnp_build_option(dev, IORESOURCE_DMA, option_flags);
86 	if (!option)
87 		return -ENOMEM;
88 
89 	dma = &option->u.dma;
90 	dma->map = map;
91 	dma->flags = flags;
92 
93 	dbg_pnp_show_option(dev, option);
94 	return 0;
95 }
96 
97 int pnp_register_port_resource(struct pnp_dev *dev, unsigned int option_flags,
98 			       resource_size_t min, resource_size_t max,
99 			       resource_size_t align, resource_size_t size,
100 			       unsigned char flags)
101 {
102 	struct pnp_option *option;
103 	struct pnp_port *port;
104 
105 	option = pnp_build_option(dev, IORESOURCE_IO, option_flags);
106 	if (!option)
107 		return -ENOMEM;
108 
109 	port = &option->u.port;
110 	port->min = min;
111 	port->max = max;
112 	port->align = align;
113 	port->size = size;
114 	port->flags = flags;
115 
116 	dbg_pnp_show_option(dev, option);
117 	return 0;
118 }
119 
120 int pnp_register_mem_resource(struct pnp_dev *dev, unsigned int option_flags,
121 			      resource_size_t min, resource_size_t max,
122 			      resource_size_t align, resource_size_t size,
123 			      unsigned char flags)
124 {
125 	struct pnp_option *option;
126 	struct pnp_mem *mem;
127 
128 	option = pnp_build_option(dev, IORESOURCE_MEM, option_flags);
129 	if (!option)
130 		return -ENOMEM;
131 
132 	mem = &option->u.mem;
133 	mem->min = min;
134 	mem->max = max;
135 	mem->align = align;
136 	mem->size = size;
137 	mem->flags = flags;
138 
139 	dbg_pnp_show_option(dev, option);
140 	return 0;
141 }
142 
143 void pnp_free_options(struct pnp_dev *dev)
144 {
145 	struct pnp_option *option, *tmp;
146 
147 	list_for_each_entry_safe(option, tmp, &dev->options, list) {
148 		list_del(&option->list);
149 		kfree(option);
150 	}
151 }
152 
153 /*
154  * resource validity checking
155  */
156 
157 #define length(start, end) (*(end) - *(start) + 1)
158 
159 /* Two ranges conflict if one doesn't end before the other starts */
160 #define ranged_conflict(starta, enda, startb, endb) \
161 	!((*(enda) < *(startb)) || (*(endb) < *(starta)))
162 
163 #define cannot_compare(flags) \
164 ((flags) & IORESOURCE_DISABLED)
165 
166 int pnp_check_port(struct pnp_dev *dev, struct resource *res)
167 {
168 	int i;
169 	struct pnp_dev *tdev;
170 	struct resource *tres;
171 	resource_size_t *port, *end, *tport, *tend;
172 
173 	port = &res->start;
174 	end = &res->end;
175 
176 	/* if the resource doesn't exist, don't complain about it */
177 	if (cannot_compare(res->flags))
178 		return 1;
179 
180 	/* check if the resource is already in use, skip if the
181 	 * device is active because it itself may be in use */
182 	if (!dev->active) {
183 		if (!request_region(*port, length(port, end), "pnp"))
184 			return 0;
185 		release_region(*port, length(port, end));
186 	}
187 
188 	/* check if the resource is reserved */
189 	for (i = 0; i < 8; i++) {
190 		int rport = pnp_reserve_io[i << 1];
191 		int rend = pnp_reserve_io[(i << 1) + 1] + rport - 1;
192 		if (ranged_conflict(port, end, &rport, &rend))
193 			return 0;
194 	}
195 
196 	/* check for internal conflicts */
197 	for (i = 0; (tres = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) {
198 		if (tres != res && tres->flags & IORESOURCE_IO) {
199 			tport = &tres->start;
200 			tend = &tres->end;
201 			if (ranged_conflict(port, end, tport, tend))
202 				return 0;
203 		}
204 	}
205 
206 	/* check for conflicts with other pnp devices */
207 	pnp_for_each_dev(tdev) {
208 		if (tdev == dev)
209 			continue;
210 		for (i = 0;
211 		     (tres = pnp_get_resource(tdev, IORESOURCE_IO, i));
212 		     i++) {
213 			if (tres->flags & IORESOURCE_IO) {
214 				if (cannot_compare(tres->flags))
215 					continue;
216 				if (tres->flags & IORESOURCE_WINDOW)
217 					continue;
218 				tport = &tres->start;
219 				tend = &tres->end;
220 				if (ranged_conflict(port, end, tport, tend))
221 					return 0;
222 			}
223 		}
224 	}
225 
226 	return 1;
227 }
228 
229 int pnp_check_mem(struct pnp_dev *dev, struct resource *res)
230 {
231 	int i;
232 	struct pnp_dev *tdev;
233 	struct resource *tres;
234 	resource_size_t *addr, *end, *taddr, *tend;
235 
236 	addr = &res->start;
237 	end = &res->end;
238 
239 	/* if the resource doesn't exist, don't complain about it */
240 	if (cannot_compare(res->flags))
241 		return 1;
242 
243 	/* check if the resource is already in use, skip if the
244 	 * device is active because it itself may be in use */
245 	if (!dev->active) {
246 		if (!request_mem_region(*addr, length(addr, end), "pnp"))
247 			return 0;
248 		release_mem_region(*addr, length(addr, end));
249 	}
250 
251 	/* check if the resource is reserved */
252 	for (i = 0; i < 8; i++) {
253 		int raddr = pnp_reserve_mem[i << 1];
254 		int rend = pnp_reserve_mem[(i << 1) + 1] + raddr - 1;
255 		if (ranged_conflict(addr, end, &raddr, &rend))
256 			return 0;
257 	}
258 
259 	/* check for internal conflicts */
260 	for (i = 0; (tres = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) {
261 		if (tres != res && tres->flags & IORESOURCE_MEM) {
262 			taddr = &tres->start;
263 			tend = &tres->end;
264 			if (ranged_conflict(addr, end, taddr, tend))
265 				return 0;
266 		}
267 	}
268 
269 	/* check for conflicts with other pnp devices */
270 	pnp_for_each_dev(tdev) {
271 		if (tdev == dev)
272 			continue;
273 		for (i = 0;
274 		     (tres = pnp_get_resource(tdev, IORESOURCE_MEM, i));
275 		     i++) {
276 			if (tres->flags & IORESOURCE_MEM) {
277 				if (cannot_compare(tres->flags))
278 					continue;
279 				if (tres->flags & IORESOURCE_WINDOW)
280 					continue;
281 				taddr = &tres->start;
282 				tend = &tres->end;
283 				if (ranged_conflict(addr, end, taddr, tend))
284 					return 0;
285 			}
286 		}
287 	}
288 
289 	return 1;
290 }
291 
292 static irqreturn_t pnp_test_handler(int irq, void *dev_id)
293 {
294 	return IRQ_HANDLED;
295 }
296 
297 #ifdef CONFIG_PCI
298 static int pci_dev_uses_irq(struct pnp_dev *pnp, struct pci_dev *pci,
299 			    unsigned int irq)
300 {
301 	u32 class;
302 	u8 progif;
303 
304 	if (pci->irq == irq) {
305 		pnp_dbg(&pnp->dev, "  device %s using irq %d\n",
306 			pci_name(pci), irq);
307 		return 1;
308 	}
309 
310 	/*
311 	 * See pci_setup_device() and ata_pci_sff_activate_host() for
312 	 * similar IDE legacy detection.
313 	 */
314 	pci_read_config_dword(pci, PCI_CLASS_REVISION, &class);
315 	class >>= 8;		/* discard revision ID */
316 	progif = class & 0xff;
317 	class >>= 8;
318 
319 	if (class == PCI_CLASS_STORAGE_IDE) {
320 		/*
321 		 * Unless both channels are native-PCI mode only,
322 		 * treat the compatibility IRQs as busy.
323 		 */
324 		if ((progif & 0x5) != 0x5)
325 			if (pci_get_legacy_ide_irq(pci, 0) == irq ||
326 			    pci_get_legacy_ide_irq(pci, 1) == irq) {
327 				pnp_dbg(&pnp->dev, "  legacy IDE device %s "
328 					"using irq %d\n", pci_name(pci), irq);
329 				return 1;
330 			}
331 	}
332 
333 	return 0;
334 }
335 #endif
336 
337 static int pci_uses_irq(struct pnp_dev *pnp, unsigned int irq)
338 {
339 #ifdef CONFIG_PCI
340 	struct pci_dev *pci = NULL;
341 
342 	for_each_pci_dev(pci) {
343 		if (pci_dev_uses_irq(pnp, pci, irq)) {
344 			pci_dev_put(pci);
345 			return 1;
346 		}
347 	}
348 #endif
349 	return 0;
350 }
351 
352 int pnp_check_irq(struct pnp_dev *dev, struct resource *res)
353 {
354 	int i;
355 	struct pnp_dev *tdev;
356 	struct resource *tres;
357 	resource_size_t *irq;
358 
359 	irq = &res->start;
360 
361 	/* if the resource doesn't exist, don't complain about it */
362 	if (cannot_compare(res->flags))
363 		return 1;
364 
365 	/* check if the resource is valid */
366 	if (*irq > 15)
367 		return 0;
368 
369 	/* check if the resource is reserved */
370 	for (i = 0; i < 16; i++) {
371 		if (pnp_reserve_irq[i] == *irq)
372 			return 0;
373 	}
374 
375 	/* check for internal conflicts */
376 	for (i = 0; (tres = pnp_get_resource(dev, IORESOURCE_IRQ, i)); i++) {
377 		if (tres != res && tres->flags & IORESOURCE_IRQ) {
378 			if (tres->start == *irq)
379 				return 0;
380 		}
381 	}
382 
383 	/* check if the resource is being used by a pci device */
384 	if (pci_uses_irq(dev, *irq))
385 		return 0;
386 
387 	/* check if the resource is already in use, skip if the
388 	 * device is active because it itself may be in use */
389 	if (!dev->active) {
390 		if (request_irq(*irq, pnp_test_handler,
391 				IRQF_PROBE_SHARED, "pnp", NULL))
392 			return 0;
393 		free_irq(*irq, NULL);
394 	}
395 
396 	/* check for conflicts with other pnp devices */
397 	pnp_for_each_dev(tdev) {
398 		if (tdev == dev)
399 			continue;
400 		for (i = 0;
401 		     (tres = pnp_get_resource(tdev, IORESOURCE_IRQ, i));
402 		     i++) {
403 			if (tres->flags & IORESOURCE_IRQ) {
404 				if (cannot_compare(tres->flags))
405 					continue;
406 				if (tres->start == *irq)
407 					return 0;
408 			}
409 		}
410 	}
411 
412 	return 1;
413 }
414 
415 #ifdef CONFIG_ISA_DMA_API
416 int pnp_check_dma(struct pnp_dev *dev, struct resource *res)
417 {
418 	int i;
419 	struct pnp_dev *tdev;
420 	struct resource *tres;
421 	resource_size_t *dma;
422 
423 	dma = &res->start;
424 
425 	/* if the resource doesn't exist, don't complain about it */
426 	if (cannot_compare(res->flags))
427 		return 1;
428 
429 	/* check if the resource is valid */
430 	if (*dma == 4 || *dma > 7)
431 		return 0;
432 
433 	/* check if the resource is reserved */
434 	for (i = 0; i < 8; i++) {
435 		if (pnp_reserve_dma[i] == *dma)
436 			return 0;
437 	}
438 
439 	/* check for internal conflicts */
440 	for (i = 0; (tres = pnp_get_resource(dev, IORESOURCE_DMA, i)); i++) {
441 		if (tres != res && tres->flags & IORESOURCE_DMA) {
442 			if (tres->start == *dma)
443 				return 0;
444 		}
445 	}
446 
447 	/* check if the resource is already in use, skip if the
448 	 * device is active because it itself may be in use */
449 	if (!dev->active) {
450 		if (request_dma(*dma, "pnp"))
451 			return 0;
452 		free_dma(*dma);
453 	}
454 
455 	/* check for conflicts with other pnp devices */
456 	pnp_for_each_dev(tdev) {
457 		if (tdev == dev)
458 			continue;
459 		for (i = 0;
460 		     (tres = pnp_get_resource(tdev, IORESOURCE_DMA, i));
461 		     i++) {
462 			if (tres->flags & IORESOURCE_DMA) {
463 				if (cannot_compare(tres->flags))
464 					continue;
465 				if (tres->start == *dma)
466 					return 0;
467 			}
468 		}
469 	}
470 
471 	return 1;
472 }
473 #endif /* CONFIG_ISA_DMA_API */
474 
475 unsigned long pnp_resource_type(struct resource *res)
476 {
477 	return res->flags & (IORESOURCE_IO  | IORESOURCE_MEM |
478 			     IORESOURCE_IRQ | IORESOURCE_DMA |
479 			     IORESOURCE_BUS);
480 }
481 
482 struct resource *pnp_get_resource(struct pnp_dev *dev,
483 				  unsigned long type, unsigned int num)
484 {
485 	struct pnp_resource *pnp_res;
486 	struct resource *res;
487 
488 	list_for_each_entry(pnp_res, &dev->resources, list) {
489 		res = &pnp_res->res;
490 		if (pnp_resource_type(res) == type && num-- == 0)
491 			return res;
492 	}
493 	return NULL;
494 }
495 EXPORT_SYMBOL(pnp_get_resource);
496 
497 static struct pnp_resource *pnp_new_resource(struct pnp_dev *dev)
498 {
499 	struct pnp_resource *pnp_res;
500 
501 	pnp_res = kzalloc(sizeof(struct pnp_resource), GFP_KERNEL);
502 	if (!pnp_res)
503 		return NULL;
504 
505 	list_add_tail(&pnp_res->list, &dev->resources);
506 	return pnp_res;
507 }
508 
509 struct pnp_resource *pnp_add_resource(struct pnp_dev *dev,
510 				      struct resource *res)
511 {
512 	struct pnp_resource *pnp_res;
513 
514 	pnp_res = pnp_new_resource(dev);
515 	if (!pnp_res) {
516 		dev_err(&dev->dev, "can't add resource %pR\n", res);
517 		return NULL;
518 	}
519 
520 	pnp_res->res = *res;
521 	pnp_res->res.name = dev->name;
522 	dev_dbg(&dev->dev, "%pR\n", res);
523 	return pnp_res;
524 }
525 
526 struct pnp_resource *pnp_add_irq_resource(struct pnp_dev *dev, int irq,
527 					  int flags)
528 {
529 	struct pnp_resource *pnp_res;
530 	struct resource *res;
531 
532 	pnp_res = pnp_new_resource(dev);
533 	if (!pnp_res) {
534 		dev_err(&dev->dev, "can't add resource for IRQ %d\n", irq);
535 		return NULL;
536 	}
537 
538 	res = &pnp_res->res;
539 	res->flags = IORESOURCE_IRQ | flags;
540 	res->start = irq;
541 	res->end = irq;
542 
543 	dev_printk(KERN_DEBUG, &dev->dev, "%pR\n", res);
544 	return pnp_res;
545 }
546 
547 struct pnp_resource *pnp_add_dma_resource(struct pnp_dev *dev, int dma,
548 					  int flags)
549 {
550 	struct pnp_resource *pnp_res;
551 	struct resource *res;
552 
553 	pnp_res = pnp_new_resource(dev);
554 	if (!pnp_res) {
555 		dev_err(&dev->dev, "can't add resource for DMA %d\n", dma);
556 		return NULL;
557 	}
558 
559 	res = &pnp_res->res;
560 	res->flags = IORESOURCE_DMA | flags;
561 	res->start = dma;
562 	res->end = dma;
563 
564 	dev_printk(KERN_DEBUG, &dev->dev, "%pR\n", res);
565 	return pnp_res;
566 }
567 
568 struct pnp_resource *pnp_add_io_resource(struct pnp_dev *dev,
569 					 resource_size_t start,
570 					 resource_size_t end, int flags)
571 {
572 	struct pnp_resource *pnp_res;
573 	struct resource *res;
574 
575 	pnp_res = pnp_new_resource(dev);
576 	if (!pnp_res) {
577 		dev_err(&dev->dev, "can't add resource for IO %#llx-%#llx\n",
578 			(unsigned long long) start,
579 			(unsigned long long) end);
580 		return NULL;
581 	}
582 
583 	res = &pnp_res->res;
584 	res->flags = IORESOURCE_IO | flags;
585 	res->start = start;
586 	res->end = end;
587 
588 	dev_printk(KERN_DEBUG, &dev->dev, "%pR\n", res);
589 	return pnp_res;
590 }
591 
592 struct pnp_resource *pnp_add_mem_resource(struct pnp_dev *dev,
593 					  resource_size_t start,
594 					  resource_size_t end, int flags)
595 {
596 	struct pnp_resource *pnp_res;
597 	struct resource *res;
598 
599 	pnp_res = pnp_new_resource(dev);
600 	if (!pnp_res) {
601 		dev_err(&dev->dev, "can't add resource for MEM %#llx-%#llx\n",
602 			(unsigned long long) start,
603 			(unsigned long long) end);
604 		return NULL;
605 	}
606 
607 	res = &pnp_res->res;
608 	res->flags = IORESOURCE_MEM | flags;
609 	res->start = start;
610 	res->end = end;
611 
612 	dev_printk(KERN_DEBUG, &dev->dev, "%pR\n", res);
613 	return pnp_res;
614 }
615 
616 struct pnp_resource *pnp_add_bus_resource(struct pnp_dev *dev,
617 					  resource_size_t start,
618 					  resource_size_t end)
619 {
620 	struct pnp_resource *pnp_res;
621 	struct resource *res;
622 
623 	pnp_res = pnp_new_resource(dev);
624 	if (!pnp_res) {
625 		dev_err(&dev->dev, "can't add resource for BUS %#llx-%#llx\n",
626 			(unsigned long long) start,
627 			(unsigned long long) end);
628 		return NULL;
629 	}
630 
631 	res = &pnp_res->res;
632 	res->flags = IORESOURCE_BUS;
633 	res->start = start;
634 	res->end = end;
635 
636 	dev_printk(KERN_DEBUG, &dev->dev, "%pR\n", res);
637 	return pnp_res;
638 }
639 
640 /*
641  * Determine whether the specified resource is a possible configuration
642  * for this device.
643  */
644 int pnp_possible_config(struct pnp_dev *dev, int type, resource_size_t start,
645 			resource_size_t size)
646 {
647 	struct pnp_option *option;
648 	struct pnp_port *port;
649 	struct pnp_mem *mem;
650 	struct pnp_irq *irq;
651 	struct pnp_dma *dma;
652 
653 	list_for_each_entry(option, &dev->options, list) {
654 		if (option->type != type)
655 			continue;
656 
657 		switch (option->type) {
658 		case IORESOURCE_IO:
659 			port = &option->u.port;
660 			if (port->min == start && port->size == size)
661 				return 1;
662 			break;
663 		case IORESOURCE_MEM:
664 			mem = &option->u.mem;
665 			if (mem->min == start && mem->size == size)
666 				return 1;
667 			break;
668 		case IORESOURCE_IRQ:
669 			irq = &option->u.irq;
670 			if (start < PNP_IRQ_NR &&
671 			    test_bit(start, irq->map.bits))
672 				return 1;
673 			break;
674 		case IORESOURCE_DMA:
675 			dma = &option->u.dma;
676 			if (dma->map & (1 << start))
677 				return 1;
678 			break;
679 		}
680 	}
681 
682 	return 0;
683 }
684 EXPORT_SYMBOL(pnp_possible_config);
685 
686 int pnp_range_reserved(resource_size_t start, resource_size_t end)
687 {
688 	struct pnp_dev *dev;
689 	struct pnp_resource *pnp_res;
690 	resource_size_t *dev_start, *dev_end;
691 
692 	pnp_for_each_dev(dev) {
693 		list_for_each_entry(pnp_res, &dev->resources, list) {
694 			dev_start = &pnp_res->res.start;
695 			dev_end   = &pnp_res->res.end;
696 			if (ranged_conflict(&start, &end, dev_start, dev_end))
697 				return 1;
698 		}
699 	}
700 	return 0;
701 }
702 EXPORT_SYMBOL(pnp_range_reserved);
703 
704 /* format is: pnp_reserve_irq=irq1[,irq2] .... */
705 static int __init pnp_setup_reserve_irq(char *str)
706 {
707 	int i;
708 
709 	for (i = 0; i < 16; i++)
710 		if (get_option(&str, &pnp_reserve_irq[i]) != 2)
711 			break;
712 	return 1;
713 }
714 
715 __setup("pnp_reserve_irq=", pnp_setup_reserve_irq);
716 
717 /* format is: pnp_reserve_dma=dma1[,dma2] .... */
718 static int __init pnp_setup_reserve_dma(char *str)
719 {
720 	int i;
721 
722 	for (i = 0; i < 8; i++)
723 		if (get_option(&str, &pnp_reserve_dma[i]) != 2)
724 			break;
725 	return 1;
726 }
727 
728 __setup("pnp_reserve_dma=", pnp_setup_reserve_dma);
729 
730 /* format is: pnp_reserve_io=io1,size1[,io2,size2] .... */
731 static int __init pnp_setup_reserve_io(char *str)
732 {
733 	int i;
734 
735 	for (i = 0; i < 16; i++)
736 		if (get_option(&str, &pnp_reserve_io[i]) != 2)
737 			break;
738 	return 1;
739 }
740 
741 __setup("pnp_reserve_io=", pnp_setup_reserve_io);
742 
743 /* format is: pnp_reserve_mem=mem1,size1[,mem2,size2] .... */
744 static int __init pnp_setup_reserve_mem(char *str)
745 {
746 	int i;
747 
748 	for (i = 0; i < 16; i++)
749 		if (get_option(&str, &pnp_reserve_mem[i]) != 2)
750 			break;
751 	return 1;
752 }
753 
754 __setup("pnp_reserve_mem=", pnp_setup_reserve_mem);
755