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