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1 /*
2  *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
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
47 ACPI_MODULE_NAME("pci_link");
48 #define ACPI_PCI_LINK_CLASS		"pci_irq_routing"
49 #define ACPI_PCI_LINK_DEVICE_NAME	"PCI Interrupt Link"
50 #define ACPI_PCI_LINK_FILE_INFO		"info"
51 #define ACPI_PCI_LINK_FILE_STATUS	"state"
52 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
53 static int acpi_pci_link_add(struct acpi_device *device);
54 static int acpi_pci_link_remove(struct acpi_device *device, int type);
55 
56 static struct acpi_device_id link_device_ids[] = {
57 	{"PNP0C0F", 0},
58 	{"", 0},
59 };
60 MODULE_DEVICE_TABLE(acpi, link_device_ids);
61 
62 static struct acpi_driver acpi_pci_link_driver = {
63 	.name = "pci_link",
64 	.class = ACPI_PCI_LINK_CLASS,
65 	.ids = link_device_ids,
66 	.ops = {
67 		.add = acpi_pci_link_add,
68 		.remove = acpi_pci_link_remove,
69 		},
70 };
71 
72 /*
73  * If a link is initialized, we never change its active and initialized
74  * later even the link is disable. Instead, we just repick the active irq
75  */
76 struct acpi_pci_link_irq {
77 	u8 active;		/* Current IRQ */
78 	u8 triggering;		/* All IRQs */
79 	u8 polarity;	/* All IRQs */
80 	u8 resource_type;
81 	u8 possible_count;
82 	u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
83 	u8 initialized:1;
84 	u8 reserved:7;
85 };
86 
87 struct acpi_pci_link {
88 	struct list_head node;
89 	struct acpi_device *device;
90 	struct acpi_pci_link_irq irq;
91 	int refcnt;
92 };
93 
94 static struct {
95 	int count;
96 	struct list_head entries;
97 } acpi_link;
98 static DEFINE_MUTEX(acpi_link_lock);
99 
100 /* --------------------------------------------------------------------------
101                             PCI Link Device Management
102    -------------------------------------------------------------------------- */
103 
104 /*
105  * set context (link) possible list from resource list
106  */
107 static acpi_status
acpi_pci_link_check_possible(struct acpi_resource * resource,void * context)108 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
109 {
110 	struct acpi_pci_link *link = context;
111 	u32 i = 0;
112 
113 
114 	switch (resource->type) {
115 	case ACPI_RESOURCE_TYPE_START_DEPENDENT:
116 	case ACPI_RESOURCE_TYPE_END_TAG:
117 		return AE_OK;
118 	case ACPI_RESOURCE_TYPE_IRQ:
119 		{
120 			struct acpi_resource_irq *p = &resource->data.irq;
121 			if (!p || !p->interrupt_count) {
122 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
123 						  "Blank _PRS IRQ resource\n"));
124 				return AE_OK;
125 			}
126 			for (i = 0;
127 			     (i < p->interrupt_count
128 			      && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
129 				if (!p->interrupts[i]) {
130 					printk(KERN_WARNING PREFIX
131 					       "Invalid _PRS IRQ %d\n",
132 					       p->interrupts[i]);
133 					continue;
134 				}
135 				link->irq.possible[i] = p->interrupts[i];
136 				link->irq.possible_count++;
137 			}
138 			link->irq.triggering = p->triggering;
139 			link->irq.polarity = p->polarity;
140 			link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
141 			break;
142 		}
143 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
144 		{
145 			struct acpi_resource_extended_irq *p =
146 			    &resource->data.extended_irq;
147 			if (!p || !p->interrupt_count) {
148 				printk(KERN_WARNING PREFIX
149 					      "Blank _PRS EXT IRQ resource\n");
150 				return AE_OK;
151 			}
152 			for (i = 0;
153 			     (i < p->interrupt_count
154 			      && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
155 				if (!p->interrupts[i]) {
156 					printk(KERN_WARNING PREFIX
157 					       "Invalid _PRS IRQ %d\n",
158 					       p->interrupts[i]);
159 					continue;
160 				}
161 				link->irq.possible[i] = p->interrupts[i];
162 				link->irq.possible_count++;
163 			}
164 			link->irq.triggering = p->triggering;
165 			link->irq.polarity = p->polarity;
166 			link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
167 			break;
168 		}
169 	default:
170 		printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
171 		       resource->type);
172 		return AE_OK;
173 	}
174 
175 	return AE_CTRL_TERMINATE;
176 }
177 
acpi_pci_link_get_possible(struct acpi_pci_link * link)178 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
179 {
180 	acpi_status status;
181 
182 
183 	if (!link)
184 		return -EINVAL;
185 
186 	status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
187 				     acpi_pci_link_check_possible, link);
188 	if (ACPI_FAILURE(status)) {
189 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
190 		return -ENODEV;
191 	}
192 
193 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
194 			  "Found %d possible IRQs\n",
195 			  link->irq.possible_count));
196 
197 	return 0;
198 }
199 
200 static acpi_status
acpi_pci_link_check_current(struct acpi_resource * resource,void * context)201 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
202 {
203 	int *irq = (int *)context;
204 
205 
206 	switch (resource->type) {
207 	case ACPI_RESOURCE_TYPE_START_DEPENDENT:
208 	case ACPI_RESOURCE_TYPE_END_TAG:
209 		return AE_OK;
210 	case ACPI_RESOURCE_TYPE_IRQ:
211 		{
212 			struct acpi_resource_irq *p = &resource->data.irq;
213 			if (!p || !p->interrupt_count) {
214 				/*
215 				 * IRQ descriptors may have no IRQ# bits set,
216 				 * particularly those those w/ _STA disabled
217 				 */
218 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
219 						  "Blank _CRS IRQ resource\n"));
220 				return AE_OK;
221 			}
222 			*irq = p->interrupts[0];
223 			break;
224 		}
225 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
226 		{
227 			struct acpi_resource_extended_irq *p =
228 			    &resource->data.extended_irq;
229 			if (!p || !p->interrupt_count) {
230 				/*
231 				 * extended IRQ descriptors must
232 				 * return at least 1 IRQ
233 				 */
234 				printk(KERN_WARNING PREFIX
235 					      "Blank _CRS EXT IRQ resource\n");
236 				return AE_OK;
237 			}
238 			*irq = p->interrupts[0];
239 			break;
240 		}
241 		break;
242 	default:
243 		printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
244 		       resource->type);
245 		return AE_OK;
246 	}
247 
248 	return AE_CTRL_TERMINATE;
249 }
250 
251 /*
252  * Run _CRS and set link->irq.active
253  *
254  * return value:
255  * 0 - success
256  * !0 - failure
257  */
acpi_pci_link_get_current(struct acpi_pci_link * link)258 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
259 {
260 	int result = 0;
261 	acpi_status status = AE_OK;
262 	int irq = 0;
263 
264 	if (!link)
265 		return -EINVAL;
266 
267 	link->irq.active = 0;
268 
269 	/* in practice, status disabled is meaningless, ignore it */
270 	if (acpi_strict) {
271 		/* Query _STA, set link->device->status */
272 		result = acpi_bus_get_status(link->device);
273 		if (result) {
274 			printk(KERN_ERR PREFIX "Unable to read status\n");
275 			goto end;
276 		}
277 
278 		if (!link->device->status.enabled) {
279 			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
280 			return 0;
281 		}
282 	}
283 
284 	/*
285 	 * Query and parse _CRS to get the current IRQ assignment.
286 	 */
287 
288 	status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
289 				     acpi_pci_link_check_current, &irq);
290 	if (ACPI_FAILURE(status)) {
291 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
292 		result = -ENODEV;
293 		goto end;
294 	}
295 
296 	if (acpi_strict && !irq) {
297 		printk(KERN_ERR PREFIX "_CRS returned 0\n");
298 		result = -ENODEV;
299 	}
300 
301 	link->irq.active = irq;
302 
303 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
304 
305       end:
306 	return result;
307 }
308 
acpi_pci_link_set(struct acpi_pci_link * link,int irq)309 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
310 {
311 	int result = 0;
312 	acpi_status status = AE_OK;
313 	struct {
314 		struct acpi_resource res;
315 		struct acpi_resource end;
316 	} *resource;
317 	struct acpi_buffer buffer = { 0, NULL };
318 
319 
320 	if (!link || !irq)
321 		return -EINVAL;
322 
323 	resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
324 	if (!resource)
325 		return -ENOMEM;
326 
327 	buffer.length = sizeof(*resource) + 1;
328 	buffer.pointer = resource;
329 
330 	switch (link->irq.resource_type) {
331 	case ACPI_RESOURCE_TYPE_IRQ:
332 		resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
333 		resource->res.length = sizeof(struct acpi_resource);
334 		resource->res.data.irq.triggering = link->irq.triggering;
335 		resource->res.data.irq.polarity =
336 		    link->irq.polarity;
337 		if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
338 			resource->res.data.irq.sharable =
339 			    ACPI_EXCLUSIVE;
340 		else
341 			resource->res.data.irq.sharable = ACPI_SHARED;
342 		resource->res.data.irq.interrupt_count = 1;
343 		resource->res.data.irq.interrupts[0] = irq;
344 		break;
345 
346 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
347 		resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
348 		resource->res.length = sizeof(struct acpi_resource);
349 		resource->res.data.extended_irq.producer_consumer =
350 		    ACPI_CONSUMER;
351 		resource->res.data.extended_irq.triggering =
352 		    link->irq.triggering;
353 		resource->res.data.extended_irq.polarity =
354 		    link->irq.polarity;
355 		if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
356 			resource->res.data.irq.sharable =
357 			    ACPI_EXCLUSIVE;
358 		else
359 			resource->res.data.irq.sharable = ACPI_SHARED;
360 		resource->res.data.extended_irq.interrupt_count = 1;
361 		resource->res.data.extended_irq.interrupts[0] = irq;
362 		/* ignore resource_source, it's optional */
363 		break;
364 	default:
365 		printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
366 		result = -EINVAL;
367 		goto end;
368 
369 	}
370 	resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
371 
372 	/* Attempt to set the resource */
373 	status = acpi_set_current_resources(link->device->handle, &buffer);
374 
375 	/* check for total failure */
376 	if (ACPI_FAILURE(status)) {
377 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
378 		result = -ENODEV;
379 		goto end;
380 	}
381 
382 	/* Query _STA, set device->status */
383 	result = acpi_bus_get_status(link->device);
384 	if (result) {
385 		printk(KERN_ERR PREFIX "Unable to read status\n");
386 		goto end;
387 	}
388 	if (!link->device->status.enabled) {
389 		printk(KERN_WARNING PREFIX
390 			      "%s [%s] disabled and referenced, BIOS bug\n",
391 			      acpi_device_name(link->device),
392 			      acpi_device_bid(link->device));
393 	}
394 
395 	/* Query _CRS, set link->irq.active */
396 	result = acpi_pci_link_get_current(link);
397 	if (result) {
398 		goto end;
399 	}
400 
401 	/*
402 	 * Is current setting not what we set?
403 	 * set link->irq.active
404 	 */
405 	if (link->irq.active != irq) {
406 		/*
407 		 * policy: when _CRS doesn't return what we just _SRS
408 		 * assume _SRS worked and override _CRS value.
409 		 */
410 		printk(KERN_WARNING PREFIX
411 			      "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
412 			      acpi_device_name(link->device),
413 			      acpi_device_bid(link->device), link->irq.active, irq);
414 		link->irq.active = irq;
415 	}
416 
417 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
418 
419       end:
420 	kfree(resource);
421 	return result;
422 }
423 
424 /* --------------------------------------------------------------------------
425                             PCI Link IRQ Management
426    -------------------------------------------------------------------------- */
427 
428 /*
429  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
430  * Link Devices to move the PIRQs around to minimize sharing.
431  *
432  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
433  * that the BIOS has already set to active.  This is necessary because
434  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
435  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
436  * even if acpi_irq_nobalance is set.
437  *
438  * A tables of penalties avoids directing PCI interrupts to well known
439  * ISA IRQs. Boot params are available to over-ride the default table:
440  *
441  * List interrupts that are free for PCI use.
442  * acpi_irq_pci=n[,m]
443  *
444  * List interrupts that should not be used for PCI:
445  * acpi_irq_isa=n[,m]
446  *
447  * Note that PCI IRQ routers have a list of possible IRQs,
448  * which may not include the IRQs this table says are available.
449  *
450  * Since this heuristic can't tell the difference between a link
451  * that no device will attach to, vs. a link which may be shared
452  * by multiple active devices -- it is not optimal.
453  *
454  * If interrupt performance is that important, get an IO-APIC system
455  * with a pin dedicated to each device.  Or for that matter, an MSI
456  * enabled system.
457  */
458 
459 #define ACPI_MAX_IRQS		256
460 #define ACPI_MAX_ISA_IRQ	16
461 
462 #define PIRQ_PENALTY_PCI_AVAILABLE	(0)
463 #define PIRQ_PENALTY_PCI_POSSIBLE	(16*16)
464 #define PIRQ_PENALTY_PCI_USING		(16*16*16)
465 #define PIRQ_PENALTY_ISA_TYPICAL	(16*16*16*16)
466 #define PIRQ_PENALTY_ISA_USED		(16*16*16*16*16)
467 #define PIRQ_PENALTY_ISA_ALWAYS		(16*16*16*16*16*16)
468 
469 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
470 	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ0 timer */
471 	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ1 keyboard */
472 	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ2 cascade */
473 	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ3 serial */
474 	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ4 serial */
475 	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ5 sometimes SoundBlaster */
476 	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ6 */
477 	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ7 parallel, spurious */
478 	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ8 rtc, sometimes */
479 	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ9  PCI, often acpi */
480 	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ10 PCI */
481 	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ11 PCI */
482 	PIRQ_PENALTY_ISA_USED,	/* IRQ12 mouse */
483 	PIRQ_PENALTY_ISA_USED,	/* IRQ13 fpe, sometimes */
484 	PIRQ_PENALTY_ISA_USED,	/* IRQ14 ide0 */
485 	PIRQ_PENALTY_ISA_USED,	/* IRQ15 ide1 */
486 	/* >IRQ15 */
487 };
488 
acpi_irq_penalty_init(void)489 int __init acpi_irq_penalty_init(void)
490 {
491 	struct list_head *node = NULL;
492 	struct acpi_pci_link *link = NULL;
493 	int i = 0;
494 
495 
496 	/*
497 	 * Update penalties to facilitate IRQ balancing.
498 	 */
499 	list_for_each(node, &acpi_link.entries) {
500 
501 		link = list_entry(node, struct acpi_pci_link, node);
502 		if (!link) {
503 			printk(KERN_ERR PREFIX "Invalid link context\n");
504 			continue;
505 		}
506 
507 		/*
508 		 * reflect the possible and active irqs in the penalty table --
509 		 * useful for breaking ties.
510 		 */
511 		if (link->irq.possible_count) {
512 			int penalty =
513 			    PIRQ_PENALTY_PCI_POSSIBLE /
514 			    link->irq.possible_count;
515 
516 			for (i = 0; i < link->irq.possible_count; i++) {
517 				if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
518 					acpi_irq_penalty[link->irq.
519 							 possible[i]] +=
520 					    penalty;
521 			}
522 
523 		} else if (link->irq.active) {
524 			acpi_irq_penalty[link->irq.active] +=
525 			    PIRQ_PENALTY_PCI_POSSIBLE;
526 		}
527 	}
528 	/* Add a penalty for the SCI */
529 	acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
530 
531 	return 0;
532 }
533 
534 static int acpi_irq_balance = -1;	/* 0: static, 1: balance */
535 
acpi_pci_link_allocate(struct acpi_pci_link * link)536 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
537 {
538 	int irq;
539 	int i;
540 
541 
542 	if (link->irq.initialized) {
543 		if (link->refcnt == 0)
544 			/* This means the link is disabled but initialized */
545 			acpi_pci_link_set(link, link->irq.active);
546 		return 0;
547 	}
548 
549 	/*
550 	 * search for active IRQ in list of possible IRQs.
551 	 */
552 	for (i = 0; i < link->irq.possible_count; ++i) {
553 		if (link->irq.active == link->irq.possible[i])
554 			break;
555 	}
556 	/*
557 	 * forget active IRQ that is not in possible list
558 	 */
559 	if (i == link->irq.possible_count) {
560 		if (acpi_strict)
561 			printk(KERN_WARNING PREFIX "_CRS %d not found"
562 				      " in _PRS\n", link->irq.active);
563 		link->irq.active = 0;
564 	}
565 
566 	/*
567 	 * if active found, use it; else pick entry from end of possible list.
568 	 */
569 	if (link->irq.active) {
570 		irq = link->irq.active;
571 	} else {
572 		irq = link->irq.possible[link->irq.possible_count - 1];
573 	}
574 
575 	if (acpi_irq_balance || !link->irq.active) {
576 		/*
577 		 * Select the best IRQ.  This is done in reverse to promote
578 		 * the use of IRQs 9, 10, 11, and >15.
579 		 */
580 		for (i = (link->irq.possible_count - 1); i >= 0; i--) {
581 			if (acpi_irq_penalty[irq] >
582 			    acpi_irq_penalty[link->irq.possible[i]])
583 				irq = link->irq.possible[i];
584 		}
585 	}
586 
587 	/* Attempt to enable the link device at this IRQ. */
588 	if (acpi_pci_link_set(link, irq)) {
589 		printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
590 			    "Try pci=noacpi or acpi=off\n",
591 			    acpi_device_name(link->device),
592 			    acpi_device_bid(link->device));
593 		return -ENODEV;
594 	} else {
595 		acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
596 		printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
597 		       acpi_device_name(link->device),
598 		       acpi_device_bid(link->device), link->irq.active);
599 	}
600 
601 	link->irq.initialized = 1;
602 
603 	return 0;
604 }
605 
606 /*
607  * acpi_pci_link_allocate_irq
608  * success: return IRQ >= 0
609  * failure: return -1
610  */
611 
612 int
acpi_pci_link_allocate_irq(acpi_handle handle,int index,int * triggering,int * polarity,char ** name)613 acpi_pci_link_allocate_irq(acpi_handle handle,
614 			   int index,
615 			   int *triggering, int *polarity, char **name)
616 {
617 	int result = 0;
618 	struct acpi_device *device = NULL;
619 	struct acpi_pci_link *link = NULL;
620 
621 
622 	result = acpi_bus_get_device(handle, &device);
623 	if (result) {
624 		printk(KERN_ERR PREFIX "Invalid link device\n");
625 		return -1;
626 	}
627 
628 	link = acpi_driver_data(device);
629 	if (!link) {
630 		printk(KERN_ERR PREFIX "Invalid link context\n");
631 		return -1;
632 	}
633 
634 	/* TBD: Support multiple index (IRQ) entries per Link Device */
635 	if (index) {
636 		printk(KERN_ERR PREFIX "Invalid index %d\n", index);
637 		return -1;
638 	}
639 
640 	mutex_lock(&acpi_link_lock);
641 	if (acpi_pci_link_allocate(link)) {
642 		mutex_unlock(&acpi_link_lock);
643 		return -1;
644 	}
645 
646 	if (!link->irq.active) {
647 		mutex_unlock(&acpi_link_lock);
648 		printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
649 		return -1;
650 	}
651 	link->refcnt++;
652 	mutex_unlock(&acpi_link_lock);
653 
654 	if (triggering)
655 		*triggering = link->irq.triggering;
656 	if (polarity)
657 		*polarity = link->irq.polarity;
658 	if (name)
659 		*name = acpi_device_bid(link->device);
660 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
661 			  "Link %s is referenced\n",
662 			  acpi_device_bid(link->device)));
663 	return (link->irq.active);
664 }
665 
666 /*
667  * We don't change link's irq information here.  After it is reenabled, we
668  * continue use the info
669  */
acpi_pci_link_free_irq(acpi_handle handle)670 int acpi_pci_link_free_irq(acpi_handle handle)
671 {
672 	struct acpi_device *device = NULL;
673 	struct acpi_pci_link *link = NULL;
674 	acpi_status result;
675 
676 
677 	result = acpi_bus_get_device(handle, &device);
678 	if (result) {
679 		printk(KERN_ERR PREFIX "Invalid link device\n");
680 		return -1;
681 	}
682 
683 	link = acpi_driver_data(device);
684 	if (!link) {
685 		printk(KERN_ERR PREFIX "Invalid link context\n");
686 		return -1;
687 	}
688 
689 	mutex_lock(&acpi_link_lock);
690 	if (!link->irq.initialized) {
691 		mutex_unlock(&acpi_link_lock);
692 		printk(KERN_ERR PREFIX "Link isn't initialized\n");
693 		return -1;
694 	}
695 #ifdef	FUTURE_USE
696 	/*
697 	 * The Link reference count allows us to _DISable an unused link
698 	 * and suspend time, and set it again  on resume.
699 	 * However, 2.6.12 still has irq_router.resume
700 	 * which blindly restores the link state.
701 	 * So we disable the reference count method
702 	 * to prevent duplicate acpi_pci_link_set()
703 	 * which would harm some systems
704 	 */
705 	link->refcnt--;
706 #endif
707 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
708 			  "Link %s is dereferenced\n",
709 			  acpi_device_bid(link->device)));
710 
711 	if (link->refcnt == 0) {
712 		acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
713 	}
714 	mutex_unlock(&acpi_link_lock);
715 	return (link->irq.active);
716 }
717 
718 /* --------------------------------------------------------------------------
719                                  Driver Interface
720    -------------------------------------------------------------------------- */
721 
acpi_pci_link_add(struct acpi_device * device)722 static int acpi_pci_link_add(struct acpi_device *device)
723 {
724 	int result = 0;
725 	struct acpi_pci_link *link = NULL;
726 	int i = 0;
727 	int found = 0;
728 
729 
730 	if (!device)
731 		return -EINVAL;
732 
733 	link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
734 	if (!link)
735 		return -ENOMEM;
736 
737 	link->device = device;
738 	strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
739 	strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
740 	device->driver_data = link;
741 
742 	mutex_lock(&acpi_link_lock);
743 	result = acpi_pci_link_get_possible(link);
744 	if (result)
745 		goto end;
746 
747 	/* query and set link->irq.active */
748 	acpi_pci_link_get_current(link);
749 
750 	printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
751 	       acpi_device_bid(device));
752 	for (i = 0; i < link->irq.possible_count; i++) {
753 		if (link->irq.active == link->irq.possible[i]) {
754 			printk(" *%d", link->irq.possible[i]);
755 			found = 1;
756 		} else
757 			printk(" %d", link->irq.possible[i]);
758 	}
759 
760 	printk(")");
761 
762 	if (!found)
763 		printk(" *%d", link->irq.active);
764 
765 	if (!link->device->status.enabled)
766 		printk(", disabled.");
767 
768 	printk("\n");
769 
770 	/* TBD: Acquire/release lock */
771 	list_add_tail(&link->node, &acpi_link.entries);
772 	acpi_link.count++;
773 
774       end:
775 	/* disable all links -- to be activated on use */
776 	acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
777 	mutex_unlock(&acpi_link_lock);
778 
779 	if (result)
780 		kfree(link);
781 
782 	return result;
783 }
784 
acpi_pci_link_resume(struct acpi_pci_link * link)785 static int acpi_pci_link_resume(struct acpi_pci_link *link)
786 {
787 
788 	if (link->refcnt && link->irq.active && link->irq.initialized)
789 		return (acpi_pci_link_set(link, link->irq.active));
790 	else
791 		return 0;
792 }
793 
irqrouter_resume(struct sys_device * dev)794 static int irqrouter_resume(struct sys_device *dev)
795 {
796 	struct list_head *node = NULL;
797 	struct acpi_pci_link *link = NULL;
798 
799 	list_for_each(node, &acpi_link.entries) {
800 		link = list_entry(node, struct acpi_pci_link, node);
801 		if (!link) {
802 			printk(KERN_ERR PREFIX "Invalid link context\n");
803 			continue;
804 		}
805 		acpi_pci_link_resume(link);
806 	}
807 	return 0;
808 }
809 
acpi_pci_link_remove(struct acpi_device * device,int type)810 static int acpi_pci_link_remove(struct acpi_device *device, int type)
811 {
812 	struct acpi_pci_link *link = NULL;
813 
814 
815 	if (!device || !acpi_driver_data(device))
816 		return -EINVAL;
817 
818 	link = acpi_driver_data(device);
819 
820 	mutex_lock(&acpi_link_lock);
821 	list_del(&link->node);
822 	mutex_unlock(&acpi_link_lock);
823 
824 	kfree(link);
825 
826 	return 0;
827 }
828 
829 /*
830  * modify acpi_irq_penalty[] from cmdline
831  */
acpi_irq_penalty_update(char * str,int used)832 static int __init acpi_irq_penalty_update(char *str, int used)
833 {
834 	int i;
835 
836 	for (i = 0; i < 16; i++) {
837 		int retval;
838 		int irq;
839 
840 		retval = get_option(&str, &irq);
841 
842 		if (!retval)
843 			break;	/* no number found */
844 
845 		if (irq < 0)
846 			continue;
847 
848 		if (irq >= ARRAY_SIZE(acpi_irq_penalty))
849 			continue;
850 
851 		if (used)
852 			acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
853 		else
854 			acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
855 
856 		if (retval != 2)	/* no next number */
857 			break;
858 	}
859 	return 1;
860 }
861 
862 /*
863  * We'd like PNP to call this routine for the
864  * single ISA_USED value for each legacy device.
865  * But instead it calls us with each POSSIBLE setting.
866  * There is no ISA_POSSIBLE weight, so we simply use
867  * the (small) PCI_USING penalty.
868  */
acpi_penalize_isa_irq(int irq,int active)869 void acpi_penalize_isa_irq(int irq, int active)
870 {
871 	if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
872 		if (active)
873 			acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
874 		else
875 			acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
876 	}
877 }
878 
879 /*
880  * Over-ride default table to reserve additional IRQs for use by ISA
881  * e.g. acpi_irq_isa=5
882  * Useful for telling ACPI how not to interfere with your ISA sound card.
883  */
acpi_irq_isa(char * str)884 static int __init acpi_irq_isa(char *str)
885 {
886 	return acpi_irq_penalty_update(str, 1);
887 }
888 
889 __setup("acpi_irq_isa=", acpi_irq_isa);
890 
891 /*
892  * Over-ride default table to free additional IRQs for use by PCI
893  * e.g. acpi_irq_pci=7,15
894  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
895  */
acpi_irq_pci(char * str)896 static int __init acpi_irq_pci(char *str)
897 {
898 	return acpi_irq_penalty_update(str, 0);
899 }
900 
901 __setup("acpi_irq_pci=", acpi_irq_pci);
902 
acpi_irq_nobalance_set(char * str)903 static int __init acpi_irq_nobalance_set(char *str)
904 {
905 	acpi_irq_balance = 0;
906 	return 1;
907 }
908 
909 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
910 
acpi_irq_balance_set(char * str)911 static int __init acpi_irq_balance_set(char *str)
912 {
913 	acpi_irq_balance = 1;
914 	return 1;
915 }
916 
917 __setup("acpi_irq_balance", acpi_irq_balance_set);
918 
919 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
920 static struct sysdev_class irqrouter_sysdev_class = {
921 	.name = "irqrouter",
922 	.resume = irqrouter_resume,
923 };
924 
925 static struct sys_device device_irqrouter = {
926 	.id = 0,
927 	.cls = &irqrouter_sysdev_class,
928 };
929 
irqrouter_init_sysfs(void)930 static int __init irqrouter_init_sysfs(void)
931 {
932 	int error;
933 
934 
935 	if (acpi_disabled || acpi_noirq)
936 		return 0;
937 
938 	error = sysdev_class_register(&irqrouter_sysdev_class);
939 	if (!error)
940 		error = sysdev_register(&device_irqrouter);
941 
942 	return error;
943 }
944 
945 device_initcall(irqrouter_init_sysfs);
946 
acpi_pci_link_init(void)947 static int __init acpi_pci_link_init(void)
948 {
949 	if (acpi_noirq)
950 		return 0;
951 
952 	if (acpi_irq_balance == -1) {
953 		/* no command line switch: enable balancing in IOAPIC mode */
954 		if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
955 			acpi_irq_balance = 1;
956 		else
957 			acpi_irq_balance = 0;
958 	}
959 
960 	acpi_link.count = 0;
961 	INIT_LIST_HEAD(&acpi_link.entries);
962 
963 	if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
964 		return -ENODEV;
965 
966 	return 0;
967 }
968 
969 subsys_initcall(acpi_pci_link_init);
970