summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/resource.c
blob: 10561ce16ed135165cdbc8e558cb2aaea263d13b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
/*
 * drivers/acpi/resource.c - ACPI device resources interpretation.
 *
 * Copyright (C) 2012, Intel Corp.
 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/ioport.h>
#include <linux/list.h>
#include <linux/slab.h>

#ifdef CONFIG_X86
#define valid_IRQ(i) (((i) != 0) && ((i) != 2))
#else
#define valid_IRQ(i) (true)
#endif

static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
{
	u64 reslen = end - start + 1;

	/*
	 * CHECKME: len might be required to check versus a minimum
	 * length as well. 1 for io is fine, but for memory it does
	 * not make any sense at all.
	 * Note: some BIOSes report incorrect length for ACPI address space
	 * descriptor, so remove check of 'reslen == len' to avoid regression.
	 */
	if (len && reslen && start <= end)
		return true;

	pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
		io ? "io" : "mem", start, end, len);

	return false;
}

static void acpi_dev_memresource_flags(struct resource *res, u64 len,
				       u8 write_protect)
{
	res->flags = IORESOURCE_MEM;

	if (!acpi_dev_resource_len_valid(res->start, res->end, len, false))
		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;

	if (write_protect == ACPI_READ_WRITE_MEMORY)
		res->flags |= IORESOURCE_MEM_WRITEABLE;
}

static void acpi_dev_get_memresource(struct resource *res, u64 start, u64 len,
				     u8 write_protect)
{
	res->start = start;
	res->end = start + len - 1;
	acpi_dev_memresource_flags(res, len, write_protect);
}

/**
 * acpi_dev_resource_memory - Extract ACPI memory resource information.
 * @ares: Input ACPI resource object.
 * @res: Output generic resource object.
 *
 * Check if the given ACPI resource object represents a memory resource and
 * if that's the case, use the information in it to populate the generic
 * resource object pointed to by @res.
 *
 * Return:
 * 1) false with res->flags setting to zero: not the expected resource type
 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
 * 3) true: valid assigned resource
 */
bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
{
	struct acpi_resource_memory24 *memory24;
	struct acpi_resource_memory32 *memory32;
	struct acpi_resource_fixed_memory32 *fixed_memory32;

	switch (ares->type) {
	case ACPI_RESOURCE_TYPE_MEMORY24:
		memory24 = &ares->data.memory24;
		acpi_dev_get_memresource(res, memory24->minimum << 8,
					 memory24->address_length << 8,
					 memory24->write_protect);
		break;
	case ACPI_RESOURCE_TYPE_MEMORY32:
		memory32 = &ares->data.memory32;
		acpi_dev_get_memresource(res, memory32->minimum,
					 memory32->address_length,
					 memory32->write_protect);
		break;
	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
		fixed_memory32 = &ares->data.fixed_memory32;
		acpi_dev_get_memresource(res, fixed_memory32->address,
					 fixed_memory32->address_length,
					 fixed_memory32->write_protect);
		break;
	default:
		res->flags = 0;
		return false;
	}

	return !(res->flags & IORESOURCE_DISABLED);
}
EXPORT_SYMBOL_GPL(acpi_dev_resource_memory);

static void acpi_dev_ioresource_flags(struct resource *res, u64 len,
				      u8 io_decode)
{
	res->flags = IORESOURCE_IO;

	if (!acpi_dev_resource_len_valid(res->start, res->end, len, true))
		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;

	if (res->end >= 0x10003)
		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;

	if (io_decode == ACPI_DECODE_16)
		res->flags |= IORESOURCE_IO_16BIT_ADDR;
}

static void acpi_dev_get_ioresource(struct resource *res, u64 start, u64 len,
				    u8 io_decode)
{
	res->start = start;
	res->end = start + len - 1;
	acpi_dev_ioresource_flags(res, len, io_decode);
}

/**
 * acpi_dev_resource_io - Extract ACPI I/O resource information.
 * @ares: Input ACPI resource object.
 * @res: Output generic resource object.
 *
 * Check if the given ACPI resource object represents an I/O resource and
 * if that's the case, use the information in it to populate the generic
 * resource object pointed to by @res.
 *
 * Return:
 * 1) false with res->flags setting to zero: not the expected resource type
 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
 * 3) true: valid assigned resource
 */
bool acpi_dev_resource_io(struct acpi_resource *ares, struct resource *res)
{
	struct acpi_resource_io *io;
	struct acpi_resource_fixed_io *fixed_io;

	switch (ares->type) {
	case ACPI_RESOURCE_TYPE_IO:
		io = &ares->data.io;
		acpi_dev_get_ioresource(res, io->minimum,
					io->address_length,
					io->io_decode);
		break;
	case ACPI_RESOURCE_TYPE_FIXED_IO:
		fixed_io = &ares->data.fixed_io;
		acpi_dev_get_ioresource(res, fixed_io->address,
					fixed_io->address_length,
					ACPI_DECODE_10);
		break;
	default:
		res->flags = 0;
		return false;
	}

	return !(res->flags & IORESOURCE_DISABLED);
}
EXPORT_SYMBOL_GPL(acpi_dev_resource_io);

static bool acpi_decode_space(struct resource_win *win,
			      struct acpi_resource_address *addr,
			      struct acpi_address64_attribute *attr)
{
	u8 iodec = attr->granularity == 0xfff ? ACPI_DECODE_10 : ACPI_DECODE_16;
	bool wp = addr->info.mem.write_protect;
	u64 len = attr->address_length;
	struct resource *res = &win->res;

	/*
	 * Filter out invalid descriptor according to ACPI Spec 5.0, section
	 * 6.4.3.5 Address Space Resource Descriptors.
	 */
	if ((addr->min_address_fixed != addr->max_address_fixed && len) ||
	    (addr->min_address_fixed && addr->max_address_fixed && !len))
		pr_debug("ACPI: Invalid address space min_addr_fix %d, max_addr_fix %d, len %llx\n",
			 addr->min_address_fixed, addr->max_address_fixed, len);

	res->start = attr->minimum;
	res->end = attr->maximum;

	/*
	 * For bridges that translate addresses across the bridge,
	 * translation_offset is the offset that must be added to the
	 * address on the secondary side to obtain the address on the
	 * primary side. Non-bridge devices must list 0 for all Address
	 * Translation offset bits.
	 */
	if (addr->producer_consumer == ACPI_PRODUCER) {
		res->start += attr->translation_offset;
		res->end += attr->translation_offset;
	} else if (attr->translation_offset) {
		pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
			 attr->translation_offset);
	}

	switch (addr->resource_type) {
	case ACPI_MEMORY_RANGE:
		acpi_dev_memresource_flags(res, len, wp);
		break;
	case ACPI_IO_RANGE:
		acpi_dev_ioresource_flags(res, len, iodec);
		break;
	case ACPI_BUS_NUMBER_RANGE:
		res->flags = IORESOURCE_BUS;
		break;
	default:
		return false;
	}

	win->offset = attr->translation_offset;

	if (addr->producer_consumer == ACPI_PRODUCER)
		res->flags |= IORESOURCE_WINDOW;

	if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
		res->flags |= IORESOURCE_PREFETCH;

	return !(res->flags & IORESOURCE_DISABLED);
}

/**
 * acpi_dev_resource_address_space - Extract ACPI address space information.
 * @ares: Input ACPI resource object.
 * @win: Output generic resource object.
 *
 * Check if the given ACPI resource object represents an address space resource
 * and if that's the case, use the information in it to populate the generic
 * resource object pointed to by @win.
 *
 * Return:
 * 1) false with win->res.flags setting to zero: not the expected resource type
 * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
 *    resource
 * 3) true: valid assigned resource
 */
bool acpi_dev_resource_address_space(struct acpi_resource *ares,
				     struct resource_win *win)
{
	struct acpi_resource_address64 addr;

	win->res.flags = 0;
	if (ACPI_FAILURE(acpi_resource_to_address64(ares, &addr)))
		return false;

	return acpi_decode_space(win, (struct acpi_resource_address *)&addr,
				 &addr.address);
}
EXPORT_SYMBOL_GPL(acpi_dev_resource_address_space);

/**
 * acpi_dev_resource_ext_address_space - Extract ACPI address space information.
 * @ares: Input ACPI resource object.
 * @win: Output generic resource object.
 *
 * Check if the given ACPI resource object represents an extended address space
 * resource and if that's the case, use the information in it to populate the
 * generic resource object pointed to by @win.
 *
 * Return:
 * 1) false with win->res.flags setting to zero: not the expected resource type
 * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
 *    resource
 * 3) true: valid assigned resource
 */
bool acpi_dev_resource_ext_address_space(struct acpi_resource *ares,
					 struct resource_win *win)
{
	struct acpi_resource_extended_address64 *ext_addr;

	win->res.flags = 0;
	if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64)
		return false;

	ext_addr = &ares->data.ext_address64;

	return acpi_decode_space(win, (struct acpi_resource_address *)ext_addr,
				 &ext_addr->address);
}
EXPORT_SYMBOL_GPL(acpi_dev_resource_ext_address_space);

/**
 * acpi_dev_irq_flags - Determine IRQ resource flags.
 * @triggering: Triggering type as provided by ACPI.
 * @polarity: Interrupt polarity as provided by ACPI.
 * @shareable: Whether or not the interrupt is shareable.
 */
unsigned long acpi_dev_irq_flags(u8 triggering, u8 polarity, u8 shareable)
{
	unsigned long flags;

	if (triggering == ACPI_LEVEL_SENSITIVE)
		flags = polarity == ACPI_ACTIVE_LOW ?
			IORESOURCE_IRQ_LOWLEVEL : IORESOURCE_IRQ_HIGHLEVEL;
	else
		flags = polarity == ACPI_ACTIVE_LOW ?
			IORESOURCE_IRQ_LOWEDGE : IORESOURCE_IRQ_HIGHEDGE;

	if (shareable == ACPI_SHARED)
		flags |= IORESOURCE_IRQ_SHAREABLE;

	return flags | IORESOURCE_IRQ;
}
EXPORT_SYMBOL_GPL(acpi_dev_irq_flags);

static void acpi_dev_irqresource_disabled(struct resource *res, u32 gsi)
{
	res->start = gsi;
	res->end = gsi;
	res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | IORESOURCE_UNSET;
}

static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
				     u8 triggering, u8 polarity, u8 shareable,
				     bool legacy)
{
	int irq, p, t;

	if (!valid_IRQ(gsi)) {
		acpi_dev_irqresource_disabled(res, gsi);
		return;
	}

	/*
	 * In IO-APIC mode, use overrided attribute. Two reasons:
	 * 1. BIOS bug in DSDT
	 * 2. BIOS uses IO-APIC mode Interrupt Source Override
	 *
	 * We do this only if we are dealing with IRQ() or IRQNoFlags()
	 * resource (the legacy ISA resources). With modern ACPI 5 devices
	 * using extended IRQ descriptors we take the IRQ configuration
	 * from _CRS directly.
	 */
	if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {
		u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
		u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;

		if (triggering != trig || polarity != pol) {
			pr_warning("ACPI: IRQ %d override to %s, %s\n", gsi,
				   t ? "level" : "edge", p ? "low" : "high");
			triggering = trig;
			polarity = pol;
		}
	}

	res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
	irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
	if (irq >= 0) {
		res->start = irq;
		res->end = irq;
	} else {
		acpi_dev_irqresource_disabled(res, gsi);
	}
}

/**
 * acpi_dev_resource_interrupt - Extract ACPI interrupt resource information.
 * @ares: Input ACPI resource object.
 * @index: Index into the array of GSIs represented by the resource.
 * @res: Output generic resource object.
 *
 * Check if the given ACPI resource object represents an interrupt resource
 * and @index does not exceed the resource's interrupt count (true is returned
 * in that case regardless of the results of the other checks)).  If that's the
 * case, register the GSI corresponding to @index from the array of interrupts
 * represented by the resource and populate the generic resource object pointed
 * to by @res accordingly.  If the registration of the GSI is not successful,
 * IORESOURCE_DISABLED will be set it that object's flags.
 *
 * Return:
 * 1) false with res->flags setting to zero: not the expected resource type
 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
 * 3) true: valid assigned resource
 */
bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
				 struct resource *res)
{
	struct acpi_resource_irq *irq;
	struct acpi_resource_extended_irq *ext_irq;

	switch (ares->type) {
	case ACPI_RESOURCE_TYPE_IRQ:
		/*
		 * Per spec, only one interrupt per descriptor is allowed in
		 * _CRS, but some firmware violates this, so parse them all.
		 */
		irq = &ares->data.irq;
		if (index >= irq->interrupt_count) {
			acpi_dev_irqresource_disabled(res, 0);
			return false;
		}
		acpi_dev_get_irqresource(res, irq->interrupts[index],
					 irq->triggering, irq->polarity,
					 irq->sharable, true);
		break;
	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
		ext_irq = &ares->data.extended_irq;
		if (index >= ext_irq->interrupt_count) {
			acpi_dev_irqresource_disabled(res, 0);
			return false;
		}
		acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
					 ext_irq->triggering, ext_irq->polarity,
					 ext_irq->sharable, false);
		break;
	default:
		res->flags = 0;
		return false;
	}

	return true;
}
EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt);

/**
 * acpi_dev_free_resource_list - Free resource from %acpi_dev_get_resources().
 * @list: The head of the resource list to free.
 */
void acpi_dev_free_resource_list(struct list_head *list)
{
	resource_list_free(list);
}
EXPORT_SYMBOL_GPL(acpi_dev_free_resource_list);

struct res_proc_context {
	struct list_head *list;
	int (*preproc)(struct acpi_resource *, void *);
	void *preproc_data;
	int count;
	int error;
};

static acpi_status acpi_dev_new_resource_entry(struct resource_win *win,
					       struct res_proc_context *c)
{
	struct resource_entry *rentry;

	rentry = resource_list_create_entry(NULL, 0);
	if (!rentry) {
		c->error = -ENOMEM;
		return AE_NO_MEMORY;
	}
	*rentry->res = win->res;
	rentry->offset = win->offset;
	resource_list_add_tail(rentry, c->list);
	c->count++;
	return AE_OK;
}

static acpi_status acpi_dev_process_resource(struct acpi_resource *ares,
					     void *context)
{
	struct res_proc_context *c = context;
	struct resource_win win;
	struct resource *res = &win.res;
	int i;

	if (c->preproc) {
		int ret;

		ret = c->preproc(ares, c->preproc_data);
		if (ret < 0) {
			c->error = ret;
			return AE_CTRL_TERMINATE;
		} else if (ret > 0) {
			return AE_OK;
		}
	}

	memset(&win, 0, sizeof(win));

	if (acpi_dev_resource_memory(ares, res)
	    || acpi_dev_resource_io(ares, res)
	    || acpi_dev_resource_address_space(ares, &win)
	    || acpi_dev_resource_ext_address_space(ares, &win))
		return acpi_dev_new_resource_entry(&win, c);

	for (i = 0; acpi_dev_resource_interrupt(ares, i, res); i++) {
		acpi_status status;

		status = acpi_dev_new_resource_entry(&win, c);
		if (ACPI_FAILURE(status))
			return status;
	}

	return AE_OK;
}

/**
 * acpi_dev_get_resources - Get current resources of a device.
 * @adev: ACPI device node to get the resources for.
 * @list: Head of the resultant list of resources (must be empty).
 * @preproc: The caller's preprocessing routine.
 * @preproc_data: Pointer passed to the caller's preprocessing routine.
 *
 * Evaluate the _CRS method for the given device node and process its output by
 * (1) executing the @preproc() rountine provided by the caller, passing the
 * resource pointer and @preproc_data to it as arguments, for each ACPI resource
 * returned and (2) converting all of the returned ACPI resources into struct
 * resource objects if possible.  If the return value of @preproc() in step (1)
 * is different from 0, step (2) is not applied to the given ACPI resource and
 * if that value is negative, the whole processing is aborted and that value is
 * returned as the final error code.
 *
 * The resultant struct resource objects are put on the list pointed to by
 * @list, that must be empty initially, as members of struct resource_entry
 * objects.  Callers of this routine should use %acpi_dev_free_resource_list() to
 * free that list.
 *
 * The number of resources in the output list is returned on success, an error
 * code reflecting the error condition is returned otherwise.
 */
int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
			   int (*preproc)(struct acpi_resource *, void *),
			   void *preproc_data)
{
	struct res_proc_context c;
	acpi_status status;

	if (!adev || !adev->handle || !list_empty(list))
		return -EINVAL;

	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
		return 0;

	c.list = list;
	c.preproc = preproc;
	c.preproc_data = preproc_data;
	c.count = 0;
	c.error = 0;
	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
				     acpi_dev_process_resource, &c);
	if (ACPI_FAILURE(status)) {
		acpi_dev_free_resource_list(list);
		return c.error ? c.error : -EIO;
	}

	return c.count;
}
EXPORT_SYMBOL_GPL(acpi_dev_get_resources);

/**
 * acpi_dev_filter_resource_type - Filter ACPI resource according to resource
 *				   types
 * @ares: Input ACPI resource object.
 * @types: Valid resource types of IORESOURCE_XXX
 *
 * This is a helper function to support acpi_dev_get_resources(), which filters
 * ACPI resource objects according to resource types.
 */
int acpi_dev_filter_resource_type(struct acpi_resource *ares,
				  unsigned long types)
{
	unsigned long type = 0;

	switch (ares->type) {
	case ACPI_RESOURCE_TYPE_MEMORY24:
	case ACPI_RESOURCE_TYPE_MEMORY32:
	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
		type = IORESOURCE_MEM;
		break;
	case ACPI_RESOURCE_TYPE_IO:
	case ACPI_RESOURCE_TYPE_FIXED_IO:
		type = IORESOURCE_IO;
		break;
	case ACPI_RESOURCE_TYPE_IRQ:
	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
		type = IORESOURCE_IRQ;
		break;
	case ACPI_RESOURCE_TYPE_DMA:
	case ACPI_RESOURCE_TYPE_FIXED_DMA:
		type = IORESOURCE_DMA;
		break;
	case ACPI_RESOURCE_TYPE_GENERIC_REGISTER:
		type = IORESOURCE_REG;
		break;
	case ACPI_RESOURCE_TYPE_ADDRESS16:
	case ACPI_RESOURCE_TYPE_ADDRESS32:
	case ACPI_RESOURCE_TYPE_ADDRESS64:
	case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
		if (ares->data.address.resource_type == ACPI_MEMORY_RANGE)
			type = IORESOURCE_MEM;
		else if (ares->data.address.resource_type == ACPI_IO_RANGE)
			type = IORESOURCE_IO;
		else if (ares->data.address.resource_type ==
			 ACPI_BUS_NUMBER_RANGE)
			type = IORESOURCE_BUS;
		break;
	default:
		break;
	}

	return (type & types) ? 0 : 1;
}
EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);

struct reserved_region {
	struct list_head node;
	u64 start;
	u64 end;
};

static LIST_HEAD(reserved_io_regions);
static LIST_HEAD(reserved_mem_regions);

static int request_range(u64 start, u64 end, u8 space_id, unsigned long flags,
			 char *desc)
{
	unsigned int length = end - start + 1;
	struct resource *res;

	res = space_id == ACPI_ADR_SPACE_SYSTEM_IO ?
		request_region(start, length, desc) :
		request_mem_region(start, length, desc);
	if (!res)
		return -EIO;

	res->flags &= ~flags;
	return 0;
}

static int add_region_before(u64 start, u64 end, u8 space_id,
			     unsigned long flags, char *desc,
			     struct list_head *head)
{
	struct reserved_region *reg;
	int error;

	reg = kmalloc(sizeof(*reg), GFP_KERNEL);
	if (!reg)
		return -ENOMEM;

	error = request_range(start, end, space_id, flags, desc);
	if (error) {
		kfree(reg);
		return error;
	}

	reg->start = start;
	reg->end = end;
	list_add_tail(&reg->node, head);
	return 0;
}

/**
 * acpi_reserve_region - Reserve an I/O or memory region as a system resource.
 * @start: Starting address of the region.
 * @length: Length of the region.
 * @space_id: Identifier of address space to reserve the region from.
 * @flags: Resource flags to clear for the region after requesting it.
 * @desc: Region description (for messages).
 *
 * Reserve an I/O or memory region as a system resource to prevent others from
 * using it.  If the new region overlaps with one of the regions (in the given
 * address space) already reserved by this routine, only the non-overlapping
 * parts of it will be reserved.
 *
 * Returned is either 0 (success) or a negative error code indicating a resource
 * reservation problem.  It is the code of the first encountered error, but the
 * routine doesn't abort until it has attempted to request all of the parts of
 * the new region that don't overlap with other regions reserved previously.
 *
 * The resources requested by this routine are never released.
 */
int acpi_reserve_region(u64 start, unsigned int length, u8 space_id,
			unsigned long flags, char *desc)
{
	struct list_head *regions;
	struct reserved_region *reg;
	u64 end = start + length - 1;
	int ret = 0, error = 0;

	if (space_id == ACPI_ADR_SPACE_SYSTEM_IO)
		regions = &reserved_io_regions;
	else if (space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
		regions = &reserved_mem_regions;
	else
		return -EINVAL;

	if (list_empty(regions))
		return add_region_before(start, end, space_id, flags, desc, regions);

	list_for_each_entry(reg, regions, node)
		if (reg->start == end + 1) {
			/* The new region can be prepended to this one. */
			ret = request_range(start, end, space_id, flags, desc);
			if (!ret)
				reg->start = start;

			return ret;
		} else if (reg->start > end) {
			/* No overlap.  Add the new region here and get out. */
			return add_region_before(start, end, space_id, flags,
						 desc, &reg->node);
		} else if (reg->end == start - 1) {
			goto combine;
		} else if (reg->end >= start) {
			goto overlap;
		}

	/* The new region goes after the last existing one. */
	return add_region_before(start, end, space_id, flags, desc, regions);

 overlap:
	/*
	 * The new region overlaps an existing one.
	 *
	 * The head part of the new region immediately preceding the existing
	 * overlapping one can be combined with it right away.
	 */
	if (reg->start > start) {
		error = request_range(start, reg->start - 1, space_id, flags, desc);
		if (error)
			ret = error;
		else
			reg->start = start;
	}

 combine:
	/*
	 * The new region is adjacent to an existing one.  If it extends beyond
	 * that region all the way to the next one, it is possible to combine
	 * all three of them.
	 */
	while (reg->end < end) {
		struct reserved_region *next = NULL;
		u64 a = reg->end + 1, b = end;

		if (!list_is_last(&reg->node, regions)) {
			next = list_next_entry(reg, node);
			if (next->start <= end)
				b = next->start - 1;
		}
		error = request_range(a, b, space_id, flags, desc);
		if (!error) {
			if (next && next->start == b + 1) {
				reg->end = next->end;
				list_del(&next->node);
				kfree(next);
			} else {
				reg->end = end;
				break;
			}
		} else if (next) {
			if (!ret)
				ret = error;

			reg = next;
		} else {
			break;
		}
	}

	return ret ? ret : error;
}
EXPORT_SYMBOL_GPL(acpi_reserve_region);