1/*
2 *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 1.1.1.1 $)
3 *
4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
10 *  This program is free software; you can redistribute it and/or modify
11 *  it under the terms of the GNU General Public License as published by
12 *  the Free Software Foundation; either version 2 of the License, or (at
13 *  your option) any later version.
14 *
15 *  This program is distributed in the hope that it will be useful, but
16 *  WITHOUT ANY WARRANTY; without even the implied warranty of
17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 *  General Public License for more details.
19 *
20 *  You should have received a copy of the GNU General Public License along
21 *  with this program; if not, write to the Free Software Foundation, Inc.,
22 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23 *
24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25 *
26 * TBD:
27 *      1. Support more than one IRQ resource entry per link device (index).
28 *	2. Implement start/stop mechanism and use ACPI Bus Driver facilities
29 *	   for IRQ management (e.g. start()->_SRS).
30 */
31
32#include <linux/sysdev.h>
33#include <linux/kernel.h>
34#include <linux/module.h>
35#include <linux/init.h>
36#include <linux/types.h>
37#include <linux/proc_fs.h>
38#include <linux/spinlock.h>
39#include <linux/pm.h>
40#include <linux/pci.h>
41#include <linux/mutex.h>
42
43#include <acpi/acpi_bus.h>
44#include <acpi/acpi_drivers.h>
45
46#define _COMPONENT		ACPI_PCI_COMPONENT
47ACPI_MODULE_NAME("pci_link");
48#define ACPI_PCI_LINK_CLASS		"pci_irq_routing"
49#define ACPI_PCI_LINK_HID		"PNP0C0F"
50#define ACPI_PCI_LINK_DEVICE_NAME	"PCI Interrupt Link"
51#define ACPI_PCI_LINK_FILE_INFO		"info"
52#define ACPI_PCI_LINK_FILE_STATUS	"state"
53#define ACPI_PCI_LINK_MAX_POSSIBLE 16
54static int acpi_pci_link_add(struct acpi_device *device);
55static int acpi_pci_link_remove(struct acpi_device *device, int type);
56
57static struct acpi_driver acpi_pci_link_driver = {
58	.name = "pci_link",
59	.class = ACPI_PCI_LINK_CLASS,
60	.ids = ACPI_PCI_LINK_HID,
61	.ops = {
62		.add = acpi_pci_link_add,
63		.remove = acpi_pci_link_remove,
64		},
65};
66
67/*
68 * If a link is initialized, we never change its active and initialized
69 * later even the link is disable. Instead, we just repick the active irq
70 */
71struct acpi_pci_link_irq {
72	u8 active;		/* Current IRQ */
73	u8 triggering;		/* All IRQs */
74	u8 polarity;	/* All IRQs */
75	u8 resource_type;
76	u8 possible_count;
77	u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
78	u8 initialized:1;
79	u8 reserved:7;
80};
81
82struct acpi_pci_link {
83	struct list_head node;
84	struct acpi_device *device;
85	struct acpi_pci_link_irq irq;
86	int refcnt;
87};
88
89static struct {
90	int count;
91	struct list_head entries;
92} acpi_link;
93DEFINE_MUTEX(acpi_link_lock);
94
95/* --------------------------------------------------------------------------
96                            PCI Link Device Management
97   -------------------------------------------------------------------------- */
98
99/*
100 * set context (link) possible list from resource list
101 */
102static acpi_status
103acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
104{
105	struct acpi_pci_link *link = context;
106	u32 i = 0;
107
108
109	switch (resource->type) {
110	case ACPI_RESOURCE_TYPE_START_DEPENDENT:
111		return AE_OK;
112	case ACPI_RESOURCE_TYPE_IRQ:
113		{
114			struct acpi_resource_irq *p = &resource->data.irq;
115			if (!p || !p->interrupt_count) {
116				printk(KERN_WARNING PREFIX "Blank IRQ resource\n");
117				return AE_OK;
118			}
119			for (i = 0;
120			     (i < p->interrupt_count
121			      && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
122				if (!p->interrupts[i]) {
123					printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
124						      p->interrupts[i]);
125					continue;
126				}
127				link->irq.possible[i] = p->interrupts[i];
128				link->irq.possible_count++;
129			}
130			link->irq.triggering = p->triggering;
131			link->irq.polarity = p->polarity;
132			link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
133			break;
134		}
135	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
136		{
137			struct acpi_resource_extended_irq *p =
138			    &resource->data.extended_irq;
139			if (!p || !p->interrupt_count) {
140				printk(KERN_WARNING PREFIX
141					      "Blank EXT IRQ resource\n");
142				return AE_OK;
143			}
144			for (i = 0;
145			     (i < p->interrupt_count
146			      && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
147				if (!p->interrupts[i]) {
148					printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
149						      p->interrupts[i]);
150					continue;
151				}
152				link->irq.possible[i] = p->interrupts[i];
153				link->irq.possible_count++;
154			}
155			link->irq.triggering = p->triggering;
156			link->irq.polarity = p->polarity;
157			link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
158			break;
159		}
160	default:
161		printk(KERN_ERR PREFIX "Resource is not an IRQ entry\n");
162		return AE_OK;
163	}
164
165	return AE_CTRL_TERMINATE;
166}
167
168static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
169{
170	acpi_status status;
171
172
173	if (!link)
174		return -EINVAL;
175
176	status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
177				     acpi_pci_link_check_possible, link);
178	if (ACPI_FAILURE(status)) {
179		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
180		return -ENODEV;
181	}
182
183	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
184			  "Found %d possible IRQs\n",
185			  link->irq.possible_count));
186
187	return 0;
188}
189
190static acpi_status
191acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
192{
193	int *irq = (int *)context;
194
195
196	switch (resource->type) {
197	case ACPI_RESOURCE_TYPE_IRQ:
198		{
199			struct acpi_resource_irq *p = &resource->data.irq;
200			if (!p || !p->interrupt_count) {
201				/*
202				 * IRQ descriptors may have no IRQ# bits set,
203				 * particularly those those w/ _STA disabled
204				 */
205				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
206						  "Blank IRQ resource\n"));
207				return AE_OK;
208			}
209			*irq = p->interrupts[0];
210			break;
211		}
212	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
213		{
214			struct acpi_resource_extended_irq *p =
215			    &resource->data.extended_irq;
216			if (!p || !p->interrupt_count) {
217				/*
218				 * extended IRQ descriptors must
219				 * return at least 1 IRQ
220				 */
221				printk(KERN_WARNING PREFIX
222					      "Blank EXT IRQ resource\n");
223				return AE_OK;
224			}
225			*irq = p->interrupts[0];
226			break;
227		}
228		break;
229	default:
230		printk(KERN_ERR PREFIX "Resource %d isn't an IRQ\n", resource->type);
231	case ACPI_RESOURCE_TYPE_END_TAG:
232		return AE_OK;
233	}
234	return AE_CTRL_TERMINATE;
235}
236
237/*
238 * Run _CRS and set link->irq.active
239 *
240 * return value:
241 * 0 - success
242 * !0 - failure
243 */
244static int acpi_pci_link_get_current(struct acpi_pci_link *link)
245{
246	int result = 0;
247	acpi_status status = AE_OK;
248	int irq = 0;
249
250	if (!link)
251		return -EINVAL;
252
253	link->irq.active = 0;
254
255	/* in practice, status disabled is meaningless, ignore it */
256	if (acpi_strict) {
257		/* Query _STA, set link->device->status */
258		result = acpi_bus_get_status(link->device);
259		if (result) {
260			printk(KERN_ERR PREFIX "Unable to read status\n");
261			goto end;
262		}
263
264		if (!link->device->status.enabled) {
265			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
266			return 0;
267		}
268	}
269
270	/*
271	 * Query and parse _CRS to get the current IRQ assignment.
272	 */
273
274	status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
275				     acpi_pci_link_check_current, &irq);
276	if (ACPI_FAILURE(status)) {
277		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
278		result = -ENODEV;
279		goto end;
280	}
281
282	if (acpi_strict && !irq) {
283		printk(KERN_ERR PREFIX "_CRS returned 0\n");
284		result = -ENODEV;
285	}
286
287	link->irq.active = irq;
288
289	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
290
291      end:
292	return result;
293}
294
295static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
296{
297	int result = 0;
298	acpi_status status = AE_OK;
299	struct {
300		struct acpi_resource res;
301		struct acpi_resource end;
302	} *resource;
303	struct acpi_buffer buffer = { 0, NULL };
304
305
306	if (!link || !irq)
307		return -EINVAL;
308
309	resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
310	if (!resource)
311		return -ENOMEM;
312
313	buffer.length = sizeof(*resource) + 1;
314	buffer.pointer = resource;
315
316	switch (link->irq.resource_type) {
317	case ACPI_RESOURCE_TYPE_IRQ:
318		resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
319		resource->res.length = sizeof(struct acpi_resource);
320		resource->res.data.irq.triggering = link->irq.triggering;
321		resource->res.data.irq.polarity =
322		    link->irq.polarity;
323		if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
324			resource->res.data.irq.sharable =
325			    ACPI_EXCLUSIVE;
326		else
327			resource->res.data.irq.sharable = ACPI_SHARED;
328		resource->res.data.irq.interrupt_count = 1;
329		resource->res.data.irq.interrupts[0] = irq;
330		break;
331
332	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
333		resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
334		resource->res.length = sizeof(struct acpi_resource);
335		resource->res.data.extended_irq.producer_consumer =
336		    ACPI_CONSUMER;
337		resource->res.data.extended_irq.triggering =
338		    link->irq.triggering;
339		resource->res.data.extended_irq.polarity =
340		    link->irq.polarity;
341		if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
342			resource->res.data.irq.sharable =
343			    ACPI_EXCLUSIVE;
344		else
345			resource->res.data.irq.sharable = ACPI_SHARED;
346		resource->res.data.extended_irq.interrupt_count = 1;
347		resource->res.data.extended_irq.interrupts[0] = irq;
348		/* ignore resource_source, it's optional */
349		break;
350	default:
351		printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
352		result = -EINVAL;
353		goto end;
354
355	}
356	resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
357
358	/* Attempt to set the resource */
359	status = acpi_set_current_resources(link->device->handle, &buffer);
360
361	/* check for total failure */
362	if (ACPI_FAILURE(status)) {
363		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
364		result = -ENODEV;
365		goto end;
366	}
367
368	/* Query _STA, set device->status */
369	result = acpi_bus_get_status(link->device);
370	if (result) {
371		printk(KERN_ERR PREFIX "Unable to read status\n");
372		goto end;
373	}
374	if (!link->device->status.enabled) {
375		printk(KERN_WARNING PREFIX
376			      "%s [%s] disabled and referenced, BIOS bug\n",
377			      acpi_device_name(link->device),
378			      acpi_device_bid(link->device));
379	}
380
381	/* Query _CRS, set link->irq.active */
382	result = acpi_pci_link_get_current(link);
383	if (result) {
384		goto end;
385	}
386
387	/*
388	 * Is current setting not what we set?
389	 * set link->irq.active
390	 */
391	if (link->irq.active != irq) {
392		/*
393		 * policy: when _CRS doesn't return what we just _SRS
394		 * assume _SRS worked and override _CRS value.
395		 */
396		printk(KERN_WARNING PREFIX
397			      "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
398			      acpi_device_name(link->device),
399			      acpi_device_bid(link->device), link->irq.active, irq);
400		link->irq.active = irq;
401	}
402
403	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
404
405      end:
406	kfree(resource);
407	return result;
408}
409
410/* --------------------------------------------------------------------------
411                            PCI Link IRQ Management
412   -------------------------------------------------------------------------- */
413
414/*
415 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
416 * Link Devices to move the PIRQs around to minimize sharing.
417 *
418 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
419 * that the BIOS has already set to active.  This is necessary because
420 * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
421 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
422 * even if acpi_irq_nobalance is set.
423 *
424 * A tables of penalties avoids directing PCI interrupts to well known
425 * ISA IRQs. Boot params are available to over-ride the default table:
426 *
427 * List interrupts that are free for PCI use.
428 * acpi_irq_pci=n[,m]
429 *
430 * List interrupts that should not be used for PCI:
431 * acpi_irq_isa=n[,m]
432 *
433 * Note that PCI IRQ routers have a list of possible IRQs,
434 * which may not include the IRQs this table says are available.
435 *
436 * Since this heuristic can't tell the difference between a link
437 * that no device will attach to, vs. a link which may be shared
438 * by multiple active devices -- it is not optimal.
439 *
440 * If interrupt performance is that important, get an IO-APIC system
441 * with a pin dedicated to each device.  Or for that matter, an MSI
442 * enabled system.
443 */
444
445#define ACPI_MAX_IRQS		256
446#define ACPI_MAX_ISA_IRQ	16
447
448#define PIRQ_PENALTY_PCI_AVAILABLE	(0)
449#define PIRQ_PENALTY_PCI_POSSIBLE	(16*16)
450#define PIRQ_PENALTY_PCI_USING		(16*16*16)
451#define PIRQ_PENALTY_ISA_TYPICAL	(16*16*16*16)
452#define PIRQ_PENALTY_ISA_USED		(16*16*16*16*16)
453#define PIRQ_PENALTY_ISA_ALWAYS		(16*16*16*16*16*16)
454
455static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
456	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ0 timer */
457	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ1 keyboard */
458	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ2 cascade */
459	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ3 serial */
460	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ4 serial */
461	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ5 sometimes SoundBlaster */
462	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ6 */
463	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ7 parallel, spurious */
464	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ8 rtc, sometimes */
465	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ9  PCI, often acpi */
466	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ10 PCI */
467	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ11 PCI */
468	PIRQ_PENALTY_ISA_USED,	/* IRQ12 mouse */
469	PIRQ_PENALTY_ISA_USED,	/* IRQ13 fpe, sometimes */
470	PIRQ_PENALTY_ISA_USED,	/* IRQ14 ide0 */
471	PIRQ_PENALTY_ISA_USED,	/* IRQ15 ide1 */
472	/* >IRQ15 */
473};
474
475int __init acpi_irq_penalty_init(void)
476{
477	struct list_head *node = NULL;
478	struct acpi_pci_link *link = NULL;
479	int i = 0;
480
481
482	/*
483	 * Update penalties to facilitate IRQ balancing.
484	 */
485	list_for_each(node, &acpi_link.entries) {
486
487		link = list_entry(node, struct acpi_pci_link, node);
488		if (!link) {
489			printk(KERN_ERR PREFIX "Invalid link context\n");
490			continue;
491		}
492
493		/*
494		 * reflect the possible and active irqs in the penalty table --
495		 * useful for breaking ties.
496		 */
497		if (link->irq.possible_count) {
498			int penalty =
499			    PIRQ_PENALTY_PCI_POSSIBLE /
500			    link->irq.possible_count;
501
502			for (i = 0; i < link->irq.possible_count; i++) {
503				if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
504					acpi_irq_penalty[link->irq.
505							 possible[i]] +=
506					    penalty;
507			}
508
509		} else if (link->irq.active) {
510			acpi_irq_penalty[link->irq.active] +=
511			    PIRQ_PENALTY_PCI_POSSIBLE;
512		}
513	}
514	/* Add a penalty for the SCI */
515	acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
516
517	return 0;
518}
519
520static int acpi_irq_balance;	/* 0: static, 1: balance */
521
522static int acpi_pci_link_allocate(struct acpi_pci_link *link)
523{
524	int irq;
525	int i;
526
527
528	if (link->irq.initialized) {
529		if (link->refcnt == 0)
530			/* This means the link is disabled but initialized */
531			acpi_pci_link_set(link, link->irq.active);
532		return 0;
533	}
534
535	/*
536	 * search for active IRQ in list of possible IRQs.
537	 */
538	for (i = 0; i < link->irq.possible_count; ++i) {
539		if (link->irq.active == link->irq.possible[i])
540			break;
541	}
542	/*
543	 * forget active IRQ that is not in possible list
544	 */
545	if (i == link->irq.possible_count) {
546		if (acpi_strict)
547			printk(KERN_WARNING PREFIX "_CRS %d not found"
548				      " in _PRS\n", link->irq.active);
549		link->irq.active = 0;
550	}
551
552	/*
553	 * if active found, use it; else pick entry from end of possible list.
554	 */
555	if (link->irq.active) {
556		irq = link->irq.active;
557	} else {
558		irq = link->irq.possible[link->irq.possible_count - 1];
559	}
560
561	if (acpi_irq_balance || !link->irq.active) {
562		/*
563		 * Select the best IRQ.  This is done in reverse to promote
564		 * the use of IRQs 9, 10, 11, and >15.
565		 */
566		for (i = (link->irq.possible_count - 1); i >= 0; i--) {
567			if (acpi_irq_penalty[irq] >
568			    acpi_irq_penalty[link->irq.possible[i]])
569				irq = link->irq.possible[i];
570		}
571	}
572
573	/* Attempt to enable the link device at this IRQ. */
574	if (acpi_pci_link_set(link, irq)) {
575		printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
576			    "Try pci=noacpi or acpi=off\n",
577			    acpi_device_name(link->device),
578			    acpi_device_bid(link->device));
579		return -ENODEV;
580	} else {
581		acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
582		printk(PREFIX "%s [%s] enabled at IRQ %d\n",
583		       acpi_device_name(link->device),
584		       acpi_device_bid(link->device), link->irq.active);
585	}
586
587	link->irq.initialized = 1;
588
589	return 0;
590}
591
592/*
593 * acpi_pci_link_allocate_irq
594 * success: return IRQ >= 0
595 * failure: return -1
596 */
597
598int
599acpi_pci_link_allocate_irq(acpi_handle handle,
600			   int index,
601			   int *triggering, int *polarity, char **name)
602{
603	int result = 0;
604	struct acpi_device *device = NULL;
605	struct acpi_pci_link *link = NULL;
606
607
608	result = acpi_bus_get_device(handle, &device);
609	if (result) {
610		printk(KERN_ERR PREFIX "Invalid link device\n");
611		return -1;
612	}
613
614	link = acpi_driver_data(device);
615	if (!link) {
616		printk(KERN_ERR PREFIX "Invalid link context\n");
617		return -1;
618	}
619
620	/* TBD: Support multiple index (IRQ) entries per Link Device */
621	if (index) {
622		printk(KERN_ERR PREFIX "Invalid index %d\n", index);
623		return -1;
624	}
625
626	mutex_lock(&acpi_link_lock);
627	if (acpi_pci_link_allocate(link)) {
628		mutex_unlock(&acpi_link_lock);
629		return -1;
630	}
631
632	if (!link->irq.active) {
633		mutex_unlock(&acpi_link_lock);
634		printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
635		return -1;
636	}
637	link->refcnt++;
638	mutex_unlock(&acpi_link_lock);
639
640	if (triggering)
641		*triggering = link->irq.triggering;
642	if (polarity)
643		*polarity = link->irq.polarity;
644	if (name)
645		*name = acpi_device_bid(link->device);
646	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
647			  "Link %s is referenced\n",
648			  acpi_device_bid(link->device)));
649	return (link->irq.active);
650}
651
652/*
653 * We don't change link's irq information here.  After it is reenabled, we
654 * continue use the info
655 */
656int acpi_pci_link_free_irq(acpi_handle handle)
657{
658	struct acpi_device *device = NULL;
659	struct acpi_pci_link *link = NULL;
660	acpi_status result;
661
662
663	result = acpi_bus_get_device(handle, &device);
664	if (result) {
665		printk(KERN_ERR PREFIX "Invalid link device\n");
666		return -1;
667	}
668
669	link = acpi_driver_data(device);
670	if (!link) {
671		printk(KERN_ERR PREFIX "Invalid link context\n");
672		return -1;
673	}
674
675	mutex_lock(&acpi_link_lock);
676	if (!link->irq.initialized) {
677		mutex_unlock(&acpi_link_lock);
678		printk(KERN_ERR PREFIX "Link isn't initialized\n");
679		return -1;
680	}
681#ifdef	FUTURE_USE
682	/*
683	 * The Link reference count allows us to _DISable an unused link
684	 * and suspend time, and set it again  on resume.
685	 * However, 2.6.12 still has irq_router.resume
686	 * which blindly restores the link state.
687	 * So we disable the reference count method
688	 * to prevent duplicate acpi_pci_link_set()
689	 * which would harm some systems
690	 */
691	link->refcnt--;
692#endif
693	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
694			  "Link %s is dereferenced\n",
695			  acpi_device_bid(link->device)));
696
697	if (link->refcnt == 0) {
698		acpi_ut_evaluate_object(link->device->handle, "_DIS", 0, NULL);
699	}
700	mutex_unlock(&acpi_link_lock);
701	return (link->irq.active);
702}
703
704/* --------------------------------------------------------------------------
705                                 Driver Interface
706   -------------------------------------------------------------------------- */
707
708static int acpi_pci_link_add(struct acpi_device *device)
709{
710	int result = 0;
711	struct acpi_pci_link *link = NULL;
712	int i = 0;
713	int found = 0;
714
715
716	if (!device)
717		return -EINVAL;
718
719	link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
720	if (!link)
721		return -ENOMEM;
722
723	link->device = device;
724	strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
725	strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
726	acpi_driver_data(device) = link;
727
728	mutex_lock(&acpi_link_lock);
729	result = acpi_pci_link_get_possible(link);
730	if (result)
731		goto end;
732
733	/* query and set link->irq.active */
734	acpi_pci_link_get_current(link);
735
736	printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
737	       acpi_device_bid(device));
738	for (i = 0; i < link->irq.possible_count; i++) {
739		if (link->irq.active == link->irq.possible[i]) {
740			printk(" *%d", link->irq.possible[i]);
741			found = 1;
742		} else
743			printk(" %d", link->irq.possible[i]);
744	}
745
746	printk(")");
747
748	if (!found)
749		printk(" *%d", link->irq.active);
750
751	if (!link->device->status.enabled)
752		printk(", disabled.");
753
754	printk("\n");
755
756	/* TBD: Acquire/release lock */
757	list_add_tail(&link->node, &acpi_link.entries);
758	acpi_link.count++;
759
760      end:
761	/* disable all links -- to be activated on use */
762	acpi_ut_evaluate_object(device->handle, "_DIS", 0, NULL);
763	mutex_unlock(&acpi_link_lock);
764
765	if (result)
766		kfree(link);
767
768	return result;
769}
770
771static int acpi_pci_link_resume(struct acpi_pci_link *link)
772{
773
774	if (link->refcnt && link->irq.active && link->irq.initialized)
775		return (acpi_pci_link_set(link, link->irq.active));
776	else
777		return 0;
778}
779
780static int irqrouter_resume(struct sys_device *dev)
781{
782	struct list_head *node = NULL;
783	struct acpi_pci_link *link = NULL;
784
785
786	/* Make sure SCI is enabled again (Apple firmware bug?) */
787	acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
788
789	list_for_each(node, &acpi_link.entries) {
790		link = list_entry(node, struct acpi_pci_link, node);
791		if (!link) {
792			printk(KERN_ERR PREFIX "Invalid link context\n");
793			continue;
794		}
795		acpi_pci_link_resume(link);
796	}
797	return 0;
798}
799
800static int acpi_pci_link_remove(struct acpi_device *device, int type)
801{
802	struct acpi_pci_link *link = NULL;
803
804
805	if (!device || !acpi_driver_data(device))
806		return -EINVAL;
807
808	link = acpi_driver_data(device);
809
810	mutex_lock(&acpi_link_lock);
811	list_del(&link->node);
812	mutex_unlock(&acpi_link_lock);
813
814	kfree(link);
815
816	return 0;
817}
818
819/*
820 * modify acpi_irq_penalty[] from cmdline
821 */
822static int __init acpi_irq_penalty_update(char *str, int used)
823{
824	int i;
825
826	for (i = 0; i < 16; i++) {
827		int retval;
828		int irq;
829
830		retval = get_option(&str, &irq);
831
832		if (!retval)
833			break;	/* no number found */
834
835		if (irq < 0)
836			continue;
837
838		if (irq >= ACPI_MAX_IRQS)
839			continue;
840
841		if (used)
842			acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
843		else
844			acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
845
846		if (retval != 2)	/* no next number */
847			break;
848	}
849	return 1;
850}
851
852/*
853 * We'd like PNP to call this routine for the
854 * single ISA_USED value for each legacy device.
855 * But instead it calls us with each POSSIBLE setting.
856 * There is no ISA_POSSIBLE weight, so we simply use
857 * the (small) PCI_USING penalty.
858 */
859void acpi_penalize_isa_irq(int irq, int active)
860{
861	if (active)
862		acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
863	else
864		acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
865}
866
867/*
868 * Over-ride default table to reserve additional IRQs for use by ISA
869 * e.g. acpi_irq_isa=5
870 * Useful for telling ACPI how not to interfere with your ISA sound card.
871 */
872static int __init acpi_irq_isa(char *str)
873{
874	return acpi_irq_penalty_update(str, 1);
875}
876
877__setup("acpi_irq_isa=", acpi_irq_isa);
878
879/*
880 * Over-ride default table to free additional IRQs for use by PCI
881 * e.g. acpi_irq_pci=7,15
882 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
883 */
884static int __init acpi_irq_pci(char *str)
885{
886	return acpi_irq_penalty_update(str, 0);
887}
888
889__setup("acpi_irq_pci=", acpi_irq_pci);
890
891static int __init acpi_irq_nobalance_set(char *str)
892{
893	acpi_irq_balance = 0;
894	return 1;
895}
896
897__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
898
899int __init acpi_irq_balance_set(char *str)
900{
901	acpi_irq_balance = 1;
902	return 1;
903}
904
905__setup("acpi_irq_balance", acpi_irq_balance_set);
906
907static struct sysdev_class irqrouter_sysdev_class = {
908	set_kset_name("irqrouter"),
909	.resume = irqrouter_resume,
910};
911
912static struct sys_device device_irqrouter = {
913	.id = 0,
914	.cls = &irqrouter_sysdev_class,
915};
916
917static int __init irqrouter_init_sysfs(void)
918{
919	int error;
920
921
922	if (acpi_disabled || acpi_noirq)
923		return 0;
924
925	error = sysdev_class_register(&irqrouter_sysdev_class);
926	if (!error)
927		error = sysdev_register(&device_irqrouter);
928
929	return error;
930}
931
932device_initcall(irqrouter_init_sysfs);
933
934static int __init acpi_pci_link_init(void)
935{
936
937	if (acpi_noirq)
938		return 0;
939
940	acpi_link.count = 0;
941	INIT_LIST_HEAD(&acpi_link.entries);
942
943	if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
944		return -ENODEV;
945
946	return 0;
947}
948
949subsys_initcall(acpi_pci_link_init);
950