summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/pci_link.c
blob: f2271173bbd5966ffb2bda5edd862a65b03b0280 (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
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
/*
 *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * TBD: 
 *      1. Support more than one IRQ resource entry per link device (index).
 *	2. Implement start/stop mechanism and use ACPI Bus Driver facilities
 *	   for IRQ management (e.g. start()->_SRS).
 */

#include <linux/sysdev.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/pm.h>
#include <linux/pci.h>

#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>


#define _COMPONENT		ACPI_PCI_COMPONENT
ACPI_MODULE_NAME		("pci_link")

#define ACPI_PCI_LINK_CLASS		"pci_irq_routing"
#define ACPI_PCI_LINK_HID		"PNP0C0F"
#define ACPI_PCI_LINK_DRIVER_NAME	"ACPI PCI Interrupt Link Driver"
#define ACPI_PCI_LINK_DEVICE_NAME	"PCI Interrupt Link"
#define ACPI_PCI_LINK_FILE_INFO		"info"
#define ACPI_PCI_LINK_FILE_STATUS	"state"

#define ACPI_PCI_LINK_MAX_POSSIBLE 16

static int acpi_pci_link_add (struct acpi_device *device);
static int acpi_pci_link_remove (struct acpi_device *device, int type);

static struct acpi_driver acpi_pci_link_driver = {
	.name =		ACPI_PCI_LINK_DRIVER_NAME,
	.class =	ACPI_PCI_LINK_CLASS,
	.ids =		ACPI_PCI_LINK_HID,
	.ops =		{
				.add =    acpi_pci_link_add,
				.remove = acpi_pci_link_remove,
			},
};

struct acpi_pci_link_irq {
	u8			active;			/* Current IRQ */
	u8			edge_level;		/* All IRQs */
	u8			active_high_low;	/* All IRQs */
	u8			resource_type;
	u8			possible_count;
	u8			possible[ACPI_PCI_LINK_MAX_POSSIBLE];
	u8			initialized:1;
	u8			suspend_resume:1;
	u8			reserved:6;
};

struct acpi_pci_link {
	struct list_head	node;
	struct acpi_device	*device;
	acpi_handle		handle;
	struct acpi_pci_link_irq irq;
};

static struct {
	int			count;
	struct list_head	entries;
}				acpi_link;


/* --------------------------------------------------------------------------
                            PCI Link Device Management
   -------------------------------------------------------------------------- */

/*
 * set context (link) possible list from resource list
 */
static acpi_status
acpi_pci_link_check_possible (
	struct acpi_resource	*resource,
	void			*context)
{
	struct acpi_pci_link	*link = (struct acpi_pci_link *) context;
	u32			i = 0;

	ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");

	switch (resource->id) {
	case ACPI_RSTYPE_START_DPF:
		return_ACPI_STATUS(AE_OK);
	case ACPI_RSTYPE_IRQ:
	{
		struct acpi_resource_irq *p = &resource->data.irq;
		if (!p || !p->number_of_interrupts) {
			ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Blank IRQ resource\n"));
			return_ACPI_STATUS(AE_OK);
		}
		for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
			if (!p->interrupts[i]) {
				ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
				continue;
			}
			link->irq.possible[i] = p->interrupts[i];
			link->irq.possible_count++;
		}
		link->irq.edge_level = p->edge_level;
		link->irq.active_high_low = p->active_high_low;
		link->irq.resource_type = ACPI_RSTYPE_IRQ;
		break;
	}
	case ACPI_RSTYPE_EXT_IRQ:
	{
		struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
		if (!p || !p->number_of_interrupts) {
			ACPI_DEBUG_PRINT((ACPI_DB_WARN, 
				"Blank EXT IRQ resource\n"));
			return_ACPI_STATUS(AE_OK);
		}
		for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
			if (!p->interrupts[i]) {
				ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
				continue;
			}
			link->irq.possible[i] = p->interrupts[i];
			link->irq.possible_count++;
		}
		link->irq.edge_level = p->edge_level;
		link->irq.active_high_low = p->active_high_low;
		link->irq.resource_type = ACPI_RSTYPE_EXT_IRQ;
		break;
	}
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
			"Resource is not an IRQ entry\n"));
		return_ACPI_STATUS(AE_OK);
	}

	return_ACPI_STATUS(AE_CTRL_TERMINATE);
}


static int
acpi_pci_link_get_possible (
	struct acpi_pci_link	*link)
{
	acpi_status		status;

	ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");

	if (!link)
		return_VALUE(-EINVAL);

	status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
			acpi_pci_link_check_possible, link);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
		return_VALUE(-ENODEV);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
		"Found %d possible IRQs\n", link->irq.possible_count));

	return_VALUE(0);
}


static acpi_status
acpi_pci_link_check_current (
	struct acpi_resource	*resource,
	void			*context)
{
	int			*irq = (int *) context;

	ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");

	switch (resource->id) {
	case ACPI_RSTYPE_IRQ:
	{
		struct acpi_resource_irq *p = &resource->data.irq;
		if (!p || !p->number_of_interrupts) {
			/*
			 * IRQ descriptors may have no IRQ# bits set,
			 * particularly those those w/ _STA disabled
			 */
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"Blank IRQ resource\n")); 
			return_ACPI_STATUS(AE_OK);
		}
		*irq = p->interrupts[0];
		break;
	}
	case ACPI_RSTYPE_EXT_IRQ:
	{
		struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
		if (!p || !p->number_of_interrupts) {
			/*
			 * extended IRQ descriptors must
			 * return at least 1 IRQ
			 */
			ACPI_DEBUG_PRINT((ACPI_DB_WARN,
				"Blank EXT IRQ resource\n"));
			return_ACPI_STATUS(AE_OK);
		}
		*irq = p->interrupts[0];
		break;
	}
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Resource isn't an IRQ\n"));
		return_ACPI_STATUS(AE_OK);
	}
	return_ACPI_STATUS(AE_CTRL_TERMINATE);
}

/*
 * Run _CRS and set link->irq.active
 *
 * return value:
 * 0 - success
 * !0 - failure
 */
static int
acpi_pci_link_get_current (
	struct acpi_pci_link	*link)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	int			irq = 0;

	ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");

	if (!link || !link->handle)
		return_VALUE(-EINVAL);

	link->irq.active = 0;

	/* in practice, status disabled is meaningless, ignore it */
	if (acpi_strict) {
		/* Query _STA, set link->device->status */
		result = acpi_bus_get_status(link->device);
		if (result) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
			goto end;
		}

		if (!link->device->status.enabled) {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
			return_VALUE(0);
		}
	}

	/* 
	 * Query and parse _CRS to get the current IRQ assignment. 
	 */

	status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
			acpi_pci_link_check_current, &irq);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
		result = -ENODEV;
		goto end;
	}

	if (acpi_strict && !irq) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
		result = -ENODEV;
	}

	link->irq.active = irq;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));

end:
	return_VALUE(result);
}

static int
acpi_pci_link_set (
	struct acpi_pci_link	*link,
	int			irq)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	struct {
		struct acpi_resource	res;
		struct acpi_resource	end;
	}    *resource;
	struct acpi_buffer	buffer = {0, NULL};

	ACPI_FUNCTION_TRACE("acpi_pci_link_set");

	if (!link || !irq)
		return_VALUE(-EINVAL);

	resource = kmalloc( sizeof(*resource)+1, GFP_KERNEL);
	if(!resource)
		return_VALUE(-ENOMEM);

	memset(resource, 0, sizeof(*resource)+1);
	buffer.length = sizeof(*resource) +1;
	buffer.pointer = resource;

	switch(link->irq.resource_type) {
	case ACPI_RSTYPE_IRQ:
		resource->res.id = ACPI_RSTYPE_IRQ;
		resource->res.length = sizeof(struct acpi_resource);
		resource->res.data.irq.edge_level = link->irq.edge_level;
		resource->res.data.irq.active_high_low = link->irq.active_high_low;
		if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
			resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
		else
			resource->res.data.irq.shared_exclusive = ACPI_SHARED;
		resource->res.data.irq.number_of_interrupts = 1;
		resource->res.data.irq.interrupts[0] = irq;
		break;
	   
	case ACPI_RSTYPE_EXT_IRQ:
		resource->res.id = ACPI_RSTYPE_EXT_IRQ;
		resource->res.length = sizeof(struct acpi_resource);
		resource->res.data.extended_irq.producer_consumer = ACPI_CONSUMER;
		resource->res.data.extended_irq.edge_level = link->irq.edge_level;
		resource->res.data.extended_irq.active_high_low = link->irq.active_high_low;
		if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
			resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
		else
			resource->res.data.irq.shared_exclusive = ACPI_SHARED;
		resource->res.data.extended_irq.number_of_interrupts = 1;
		resource->res.data.extended_irq.interrupts[0] = irq;
		/* ignore resource_source, it's optional */
		break;
	default:
		printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
		result = -EINVAL;
		goto end;

	}
	resource->end.id = ACPI_RSTYPE_END_TAG;

	/* Attempt to set the resource */
	status = acpi_set_current_resources(link->handle, &buffer);

	/* check for total failure */
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
		result = -ENODEV;
		goto end;
	}

	/* Query _STA, set device->status */
	result = acpi_bus_get_status(link->device);
	if (result) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
		goto end;
	}
	if (!link->device->status.enabled) {
		printk(KERN_WARNING PREFIX
			"%s [%s] disabled and referenced, BIOS bug.\n",
			acpi_device_name(link->device),
			acpi_device_bid(link->device));
	}

	/* Query _CRS, set link->irq.active */
	result = acpi_pci_link_get_current(link);
	if (result) {
		goto end;
	}

	/*
	 * Is current setting not what we set?
	 * set link->irq.active
	 */
	if (link->irq.active != irq) {
		/*
		 * policy: when _CRS doesn't return what we just _SRS
		 * assume _SRS worked and override _CRS value.
		 */
		printk(KERN_WARNING PREFIX 
			"%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
			acpi_device_name(link->device),
			acpi_device_bid(link->device),
			link->irq.active, irq);
		link->irq.active = irq;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
	
end:
	kfree(resource);
	return_VALUE(result);
}


/* --------------------------------------------------------------------------
                            PCI Link IRQ Management
   -------------------------------------------------------------------------- */

/*
 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 * Link Devices to move the PIRQs around to minimize sharing.
 * 
 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 * that the BIOS has already set to active.  This is necessary because
 * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 * even if acpi_irq_nobalance is set.
 *
 * A tables of penalties avoids directing PCI interrupts to well known
 * ISA IRQs. Boot params are available to over-ride the default table:
 *
 * List interrupts that are free for PCI use.
 * acpi_irq_pci=n[,m]
 *
 * List interrupts that should not be used for PCI:
 * acpi_irq_isa=n[,m]
 *
 * Note that PCI IRQ routers have a list of possible IRQs,
 * which may not include the IRQs this table says are available.
 * 
 * Since this heuristic can't tell the difference between a link
 * that no device will attach to, vs. a link which may be shared
 * by multiple active devices -- it is not optimal.
 *
 * If interrupt performance is that important, get an IO-APIC system
 * with a pin dedicated to each device.  Or for that matter, an MSI
 * enabled system.
 */

#define ACPI_MAX_IRQS		256
#define ACPI_MAX_ISA_IRQ	16

#define PIRQ_PENALTY_PCI_AVAILABLE	(0)
#define PIRQ_PENALTY_PCI_POSSIBLE	(16*16)
#define PIRQ_PENALTY_PCI_USING		(16*16*16)
#define PIRQ_PENALTY_ISA_TYPICAL	(16*16*16*16)
#define PIRQ_PENALTY_ISA_USED		(16*16*16*16*16)
#define PIRQ_PENALTY_ISA_ALWAYS		(16*16*16*16*16*16)

static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ0 timer */
	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ1 keyboard */
	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ2 cascade */
	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ3	serial */
	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ4	serial */
	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ5 sometimes SoundBlaster */
	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ6 */
	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ7 parallel, spurious */
	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ8 rtc, sometimes */
	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ9  PCI, often acpi */
	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ10 PCI */
	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ11 PCI */
	PIRQ_PENALTY_ISA_USED,	/* IRQ12 mouse */
	PIRQ_PENALTY_ISA_USED,	/* IRQ13 fpe, sometimes */
	PIRQ_PENALTY_ISA_USED,	/* IRQ14 ide0 */
	PIRQ_PENALTY_ISA_USED,	/* IRQ15 ide1 */
			/* >IRQ15 */
};

int __init
acpi_irq_penalty_init(void)
{
	struct list_head	*node = NULL;
	struct acpi_pci_link    *link = NULL;
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");

	/*
	 * Update penalties to facilitate IRQ balancing.
	 */
	list_for_each(node, &acpi_link.entries) {

		link = list_entry(node, struct acpi_pci_link, node);
		if (!link) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
			continue;
		}

		/*
		 * reflect the possible and active irqs in the penalty table --
		 * useful for breaking ties.
		 */
		if (link->irq.possible_count) {
			int penalty = PIRQ_PENALTY_PCI_POSSIBLE / link->irq.possible_count;

			for (i = 0; i < link->irq.possible_count; i++) {
				if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
					acpi_irq_penalty[link->irq.possible[i]] += penalty;
			}

		} else if (link->irq.active) {
			acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_POSSIBLE;
		}
	}
	/* Add a penalty for the SCI */
	acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;

	return_VALUE(0);
}

static int acpi_irq_balance;	/* 0: static, 1: balance */

static int acpi_pci_link_allocate(
	struct acpi_pci_link	*link)
{
	int			irq;
	int			i;

	ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");

	if (link->irq.suspend_resume) {
		acpi_pci_link_set(link, link->irq.active);
		link->irq.suspend_resume = 0;
	}
	if (link->irq.initialized)
		return_VALUE(0);

	/*
	 * search for active IRQ in list of possible IRQs.
	 */
	for (i = 0; i < link->irq.possible_count; ++i) {
		if (link->irq.active == link->irq.possible[i])
			break;
	}
	/*
	 * forget active IRQ that is not in possible list
	 */
	if (i == link->irq.possible_count) {
		if (acpi_strict)
			printk(KERN_WARNING PREFIX "_CRS %d not found"
				" in _PRS\n", link->irq.active);
		link->irq.active = 0;
	}

	/*
	 * if active found, use it; else pick entry from end of possible list.
	 */
	if (link->irq.active) {
		irq = link->irq.active;
	} else {
		irq = link->irq.possible[link->irq.possible_count - 1];
	}

	if (acpi_irq_balance || !link->irq.active) {
		/*
		 * Select the best IRQ.  This is done in reverse to promote
		 * the use of IRQs 9, 10, 11, and >15.
		 */
		for (i = (link->irq.possible_count - 1); i >= 0; i--) {
			if (acpi_irq_penalty[irq] > acpi_irq_penalty[link->irq.possible[i]])
				irq = link->irq.possible[i];
		}
	}

	/* Attempt to enable the link device at this IRQ. */
	if (acpi_pci_link_set(link, irq)) {
		printk(PREFIX "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
				"Try pci=noacpi or acpi=off\n",
			acpi_device_name(link->device),
			acpi_device_bid(link->device));
		return_VALUE(-ENODEV);
	} else {
		acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
		printk(PREFIX "%s [%s] enabled at IRQ %d\n", 
			acpi_device_name(link->device),
			acpi_device_bid(link->device), link->irq.active);
	}

	link->irq.initialized = 1;

	return_VALUE(0);
}

/*
 * acpi_pci_link_get_irq
 * success: return IRQ >= 0
 * failure: return -1
 */

int
acpi_pci_link_get_irq (
	acpi_handle		handle,
	int			index,
	int			*edge_level,
	int			*active_high_low,
	char			**name)
{
	int                     result = 0;
	struct acpi_device	*device = NULL;
	struct acpi_pci_link	*link = NULL;

	ACPI_FUNCTION_TRACE("acpi_pci_link_get_irq");

	result = acpi_bus_get_device(handle, &device);
	if (result) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
		return_VALUE(-1);
	}

	link = (struct acpi_pci_link *) acpi_driver_data(device);
	if (!link) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
		return_VALUE(-1);
	}

	/* TBD: Support multiple index (IRQ) entries per Link Device */
	if (index) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
		return_VALUE(-1);
	}

	if (acpi_pci_link_allocate(link))
		return_VALUE(-1);
	   
	if (!link->irq.active) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
		return_VALUE(-1);
	}

	if (edge_level) *edge_level = link->irq.edge_level;
	if (active_high_low) *active_high_low = link->irq.active_high_low;
	if (name) *name = acpi_device_bid(link->device);
	return_VALUE(link->irq.active);
}


/* --------------------------------------------------------------------------
                                 Driver Interface
   -------------------------------------------------------------------------- */

static int
acpi_pci_link_add (
	struct acpi_device *device)
{
	int			result = 0;
	struct acpi_pci_link	*link = NULL;
	int			i = 0;
	int			found = 0;

	ACPI_FUNCTION_TRACE("acpi_pci_link_add");

	if (!device)
		return_VALUE(-EINVAL);

	link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
	if (!link)
		return_VALUE(-ENOMEM);
	memset(link, 0, sizeof(struct acpi_pci_link));

	link->device = device;
	link->handle = device->handle;
	strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
	acpi_driver_data(device) = link;

	result = acpi_pci_link_get_possible(link);
	if (result)
		goto end;

	/* query and set link->irq.active */
	acpi_pci_link_get_current(link);

	printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
		acpi_device_bid(device));
	for (i = 0; i < link->irq.possible_count; i++) {
		if (link->irq.active == link->irq.possible[i]) {
			printk(" *%d", link->irq.possible[i]);
			found = 1;
		}
		else
			printk(" %d", link->irq.possible[i]);
	}

	printk(")");

	if (!found)
		printk(" *%d", link->irq.active);

	if(!link->device->status.enabled)
		printk(", disabled.");

	printk("\n");

	/* TBD: Acquire/release lock */
	list_add_tail(&link->node, &acpi_link.entries);
	acpi_link.count++;

end:
	/* disable all links -- to be activated on use */
	acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);

	if (result)
		kfree(link);

	return_VALUE(result);
}

static int
irqrouter_suspend(
	struct sys_device *dev,
	u32	state)
{
	struct list_head        *node = NULL;
	struct acpi_pci_link    *link = NULL;

	ACPI_FUNCTION_TRACE("irqrouter_suspend");

	list_for_each(node, &acpi_link.entries) {
		link = list_entry(node, struct acpi_pci_link, node);
		if (!link) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
			continue;
		}
		if (link->irq.active && link->irq.initialized)
			link->irq.suspend_resume = 1;
	}
	return_VALUE(0);
}


static int
acpi_pci_link_remove (
	struct acpi_device	*device,
	int			type)
{
	struct acpi_pci_link *link = NULL;

	ACPI_FUNCTION_TRACE("acpi_pci_link_remove");

	if (!device || !acpi_driver_data(device))
		return_VALUE(-EINVAL);

	link = (struct acpi_pci_link *) acpi_driver_data(device);

	/* TBD: Acquire/release lock */
	list_del(&link->node);

	kfree(link);

	return_VALUE(0);
}

/*
 * modify acpi_irq_penalty[] from cmdline
 */
static int __init acpi_irq_penalty_update(char *str, int used)
{
	int i;

	for (i = 0; i < 16; i++) {
		int retval;
		int irq;

		retval = get_option(&str,&irq);

		if (!retval)
			break;	/* no number found */

		if (irq < 0)
			continue;
		
		if (irq >= ACPI_MAX_IRQS)
			continue;

		if (used)
			acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
		else
			acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;

		if (retval != 2)	/* no next number */
			break;
	}
	return 1;
}

/*
 * We'd like PNP to call this routine for the
 * single ISA_USED value for each legacy device.
 * But instead it calls us with each POSSIBLE setting.
 * There is no ISA_POSSIBLE weight, so we simply use
 * the (small) PCI_USING penalty.
 */
void acpi_penalize_isa_irq(int irq)
{
	acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
}

/*
 * Over-ride default table to reserve additional IRQs for use by ISA
 * e.g. acpi_irq_isa=5
 * Useful for telling ACPI how not to interfere with your ISA sound card.
 */
static int __init acpi_irq_isa(char *str)
{
	return acpi_irq_penalty_update(str, 1);
}
__setup("acpi_irq_isa=", acpi_irq_isa);

/*
 * Over-ride default table to free additional IRQs for use by PCI
 * e.g. acpi_irq_pci=7,15
 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 */
static int __init acpi_irq_pci(char *str)
{
	return acpi_irq_penalty_update(str, 0);
}
__setup("acpi_irq_pci=", acpi_irq_pci);

static int __init acpi_irq_nobalance_set(char *str)
{
	acpi_irq_balance = 0;
	return 1;
}
__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);

int __init acpi_irq_balance_set(char *str)
{
	acpi_irq_balance = 1;
	return 1;
}
__setup("acpi_irq_balance", acpi_irq_balance_set);


static struct sysdev_class irqrouter_sysdev_class = {
        set_kset_name("irqrouter"),
        .suspend = irqrouter_suspend,
};


static struct sys_device device_irqrouter = {
	.id     = 0,
	.cls    = &irqrouter_sysdev_class,
};


static int __init irqrouter_init_sysfs(void)
{
	int error;

	ACPI_FUNCTION_TRACE("irqrouter_init_sysfs");

	if (acpi_disabled || acpi_noirq)
		return_VALUE(0);

	error = sysdev_class_register(&irqrouter_sysdev_class);
	if (!error)
		error = sysdev_register(&device_irqrouter);

	return_VALUE(error);
}                                        

device_initcall(irqrouter_init_sysfs);


static int __init acpi_pci_link_init (void)
{
	ACPI_FUNCTION_TRACE("acpi_pci_link_init");

	if (acpi_noirq)
		return_VALUE(0);

	acpi_link.count = 0;
	INIT_LIST_HEAD(&acpi_link.entries);

	if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
		return_VALUE(-ENODEV);

	return_VALUE(0);
}

subsys_initcall(acpi_pci_link_init);
OpenPOWER on IntegriCloud