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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
8 *
9 * TBD:
10 * 1. Support more than one IRQ resource entry per link device (index).
11 * 2. Implement start/stop mechanism and use ACPI Bus Driver facilities
12 * for IRQ management (e.g. start()->_SRS).
13 */
14
15#include <linux/syscore_ops.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/types.h>
20#include <linux/spinlock.h>
21#include <linux/pm.h>
22#include <linux/pci.h>
23#include <linux/mutex.h>
24#include <linux/slab.h>
25#include <linux/acpi.h>
26#include <linux/irq.h>
27
28#include "internal.h"
29
30#define _COMPONENT ACPI_PCI_COMPONENT
31ACPI_MODULE_NAME("pci_link");
32#define ACPI_PCI_LINK_CLASS "pci_irq_routing"
33#define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
34#define ACPI_PCI_LINK_MAX_POSSIBLE 16
35
36static int acpi_pci_link_add(struct acpi_device *device,
37 const struct acpi_device_id *not_used);
38static void acpi_pci_link_remove(struct acpi_device *device);
39
40static const struct acpi_device_id link_device_ids[] = {
41 {"PNP0C0F", 0},
42 {"", 0},
43};
44
45static struct acpi_scan_handler pci_link_handler = {
46 .ids = link_device_ids,
47 .attach = acpi_pci_link_add,
48 .detach = acpi_pci_link_remove,
49};
50
51/*
52 * If a link is initialized, we never change its active and initialized
53 * later even the link is disable. Instead, we just repick the active irq
54 */
55struct acpi_pci_link_irq {
56 u32 active; /* Current IRQ */
57 u8 triggering; /* All IRQs */
58 u8 polarity; /* All IRQs */
59 u8 resource_type;
60 u8 possible_count;
61 u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
62 u8 initialized:1;
63 u8 reserved:7;
64};
65
66struct acpi_pci_link {
67 struct list_head list;
68 struct acpi_device *device;
69 struct acpi_pci_link_irq irq;
70 int refcnt;
71};
72
73static LIST_HEAD(acpi_link_list);
74static DEFINE_MUTEX(acpi_link_lock);
75static int sci_irq = -1, sci_penalty;
76
77/* --------------------------------------------------------------------------
78 PCI Link Device Management
79 -------------------------------------------------------------------------- */
80
81/*
82 * set context (link) possible list from resource list
83 */
84static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
85 void *context)
86{
87 struct acpi_pci_link *link = context;
88 u32 i;
89
90 switch (resource->type) {
91 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
92 case ACPI_RESOURCE_TYPE_END_TAG:
93 return AE_OK;
94 case ACPI_RESOURCE_TYPE_IRQ:
95 {
96 struct acpi_resource_irq *p = &resource->data.irq;
97 if (!p || !p->interrupt_count) {
98 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
99 "Blank _PRS IRQ resource\n"));
100 return AE_OK;
101 }
102 for (i = 0;
103 (i < p->interrupt_count
104 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
105 if (!p->interrupts[i]) {
106 printk(KERN_WARNING PREFIX
107 "Invalid _PRS IRQ %d\n",
108 p->interrupts[i]);
109 continue;
110 }
111 link->irq.possible[i] = p->interrupts[i];
112 link->irq.possible_count++;
113 }
114 link->irq.triggering = p->triggering;
115 link->irq.polarity = p->polarity;
116 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
117 break;
118 }
119 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
120 {
121 struct acpi_resource_extended_irq *p =
122 &resource->data.extended_irq;
123 if (!p || !p->interrupt_count) {
124 printk(KERN_WARNING PREFIX
125 "Blank _PRS EXT IRQ resource\n");
126 return AE_OK;
127 }
128 for (i = 0;
129 (i < p->interrupt_count
130 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
131 if (!p->interrupts[i]) {
132 printk(KERN_WARNING PREFIX
133 "Invalid _PRS IRQ %d\n",
134 p->interrupts[i]);
135 continue;
136 }
137 link->irq.possible[i] = p->interrupts[i];
138 link->irq.possible_count++;
139 }
140 link->irq.triggering = p->triggering;
141 link->irq.polarity = p->polarity;
142 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
143 break;
144 }
145 default:
146 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
147 resource->type);
148 return AE_OK;
149 }
150
151 return AE_CTRL_TERMINATE;
152}
153
154static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
155{
156 acpi_status status;
157
158 status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
159 acpi_pci_link_check_possible, link);
160 if (ACPI_FAILURE(status)) {
161 acpi_handle_debug(link->device->handle, "_PRS not present or invalid");
162 return 0;
163 }
164
165 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
166 "Found %d possible IRQs\n",
167 link->irq.possible_count));
168
169 return 0;
170}
171
172static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
173 void *context)
174{
175 int *irq = context;
176
177 switch (resource->type) {
178 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
179 case ACPI_RESOURCE_TYPE_END_TAG:
180 return AE_OK;
181 case ACPI_RESOURCE_TYPE_IRQ:
182 {
183 struct acpi_resource_irq *p = &resource->data.irq;
184 if (!p || !p->interrupt_count) {
185 /*
186 * IRQ descriptors may have no IRQ# bits set,
187 * particularly those those w/ _STA disabled
188 */
189 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
190 "Blank _CRS IRQ resource\n"));
191 return AE_OK;
192 }
193 *irq = p->interrupts[0];
194 break;
195 }
196 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
197 {
198 struct acpi_resource_extended_irq *p =
199 &resource->data.extended_irq;
200 if (!p || !p->interrupt_count) {
201 /*
202 * extended IRQ descriptors must
203 * return at least 1 IRQ
204 */
205 printk(KERN_WARNING PREFIX
206 "Blank _CRS EXT IRQ resource\n");
207 return AE_OK;
208 }
209 *irq = p->interrupts[0];
210 break;
211 }
212 break;
213 default:
214 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
215 resource->type);
216 return AE_OK;
217 }
218
219 return AE_CTRL_TERMINATE;
220}
221
222/*
223 * Run _CRS and set link->irq.active
224 *
225 * return value:
226 * 0 - success
227 * !0 - failure
228 */
229static int acpi_pci_link_get_current(struct acpi_pci_link *link)
230{
231 int result = 0;
232 acpi_status status;
233 int irq = 0;
234
235 link->irq.active = 0;
236
237 /* in practice, status disabled is meaningless, ignore it */
238 if (acpi_strict) {
239 /* Query _STA, set link->device->status */
240 result = acpi_bus_get_status(link->device);
241 if (result) {
242 printk(KERN_ERR PREFIX "Unable to read status\n");
243 goto end;
244 }
245
246 if (!link->device->status.enabled) {
247 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
248 return 0;
249 }
250 }
251
252 /*
253 * Query and parse _CRS to get the current IRQ assignment.
254 */
255
256 status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
257 acpi_pci_link_check_current, &irq);
258 if (ACPI_FAILURE(status)) {
259 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
260 result = -ENODEV;
261 goto end;
262 }
263
264 if (acpi_strict && !irq) {
265 printk(KERN_ERR PREFIX "_CRS returned 0\n");
266 result = -ENODEV;
267 }
268
269 link->irq.active = irq;
270
271 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
272
273 end:
274 return result;
275}
276
277static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
278{
279 int result;
280 acpi_status status;
281 struct {
282 struct acpi_resource res;
283 struct acpi_resource end;
284 } *resource;
285 struct acpi_buffer buffer = { 0, NULL };
286
287 if (!irq)
288 return -EINVAL;
289
290 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
291 if (!resource)
292 return -ENOMEM;
293
294 buffer.length = sizeof(*resource) + 1;
295 buffer.pointer = resource;
296
297 switch (link->irq.resource_type) {
298 case ACPI_RESOURCE_TYPE_IRQ:
299 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
300 resource->res.length = sizeof(struct acpi_resource);
301 resource->res.data.irq.triggering = link->irq.triggering;
302 resource->res.data.irq.polarity =
303 link->irq.polarity;
304 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
305 resource->res.data.irq.shareable =
306 ACPI_EXCLUSIVE;
307 else
308 resource->res.data.irq.shareable = ACPI_SHARED;
309 resource->res.data.irq.interrupt_count = 1;
310 resource->res.data.irq.interrupts[0] = irq;
311 break;
312
313 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
314 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
315 resource->res.length = sizeof(struct acpi_resource);
316 resource->res.data.extended_irq.producer_consumer =
317 ACPI_CONSUMER;
318 resource->res.data.extended_irq.triggering =
319 link->irq.triggering;
320 resource->res.data.extended_irq.polarity =
321 link->irq.polarity;
322 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
323 resource->res.data.extended_irq.shareable =
324 ACPI_EXCLUSIVE;
325 else
326 resource->res.data.extended_irq.shareable = ACPI_SHARED;
327 resource->res.data.extended_irq.interrupt_count = 1;
328 resource->res.data.extended_irq.interrupts[0] = irq;
329 /* ignore resource_source, it's optional */
330 break;
331 default:
332 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
333 result = -EINVAL;
334 goto end;
335
336 }
337 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
338 resource->end.length = sizeof(struct acpi_resource);
339
340 /* Attempt to set the resource */
341 status = acpi_set_current_resources(link->device->handle, &buffer);
342
343 /* check for total failure */
344 if (ACPI_FAILURE(status)) {
345 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
346 result = -ENODEV;
347 goto end;
348 }
349
350 /* Query _STA, set device->status */
351 result = acpi_bus_get_status(link->device);
352 if (result) {
353 printk(KERN_ERR PREFIX "Unable to read status\n");
354 goto end;
355 }
356 if (!link->device->status.enabled) {
357 printk(KERN_WARNING PREFIX
358 "%s [%s] disabled and referenced, BIOS bug\n",
359 acpi_device_name(link->device),
360 acpi_device_bid(link->device));
361 }
362
363 /* Query _CRS, set link->irq.active */
364 result = acpi_pci_link_get_current(link);
365 if (result) {
366 goto end;
367 }
368
369 /*
370 * Is current setting not what we set?
371 * set link->irq.active
372 */
373 if (link->irq.active != irq) {
374 /*
375 * policy: when _CRS doesn't return what we just _SRS
376 * assume _SRS worked and override _CRS value.
377 */
378 printk(KERN_WARNING PREFIX
379 "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
380 acpi_device_name(link->device),
381 acpi_device_bid(link->device), link->irq.active, irq);
382 link->irq.active = irq;
383 }
384
385 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
386
387 end:
388 kfree(resource);
389 return result;
390}
391
392/* --------------------------------------------------------------------------
393 PCI Link IRQ Management
394 -------------------------------------------------------------------------- */
395
396/*
397 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
398 * Link Devices to move the PIRQs around to minimize sharing.
399 *
400 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
401 * that the BIOS has already set to active. This is necessary because
402 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
403 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
404 * even if acpi_irq_nobalance is set.
405 *
406 * A tables of penalties avoids directing PCI interrupts to well known
407 * ISA IRQs. Boot params are available to over-ride the default table:
408 *
409 * List interrupts that are free for PCI use.
410 * acpi_irq_pci=n[,m]
411 *
412 * List interrupts that should not be used for PCI:
413 * acpi_irq_isa=n[,m]
414 *
415 * Note that PCI IRQ routers have a list of possible IRQs,
416 * which may not include the IRQs this table says are available.
417 *
418 * Since this heuristic can't tell the difference between a link
419 * that no device will attach to, vs. a link which may be shared
420 * by multiple active devices -- it is not optimal.
421 *
422 * If interrupt performance is that important, get an IO-APIC system
423 * with a pin dedicated to each device. Or for that matter, an MSI
424 * enabled system.
425 */
426
427#define ACPI_MAX_ISA_IRQS 16
428
429#define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
430#define PIRQ_PENALTY_PCI_USING (16*16*16)
431#define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
432#define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
433#define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
434
435static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = {
436 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
437 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
438 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
439 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
440 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
441 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
442 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
443 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
444 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
445 0, /* IRQ9 PCI, often acpi */
446 0, /* IRQ10 PCI */
447 0, /* IRQ11 PCI */
448 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
449 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
450 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
451 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
452 /* >IRQ15 */
453};
454
455static int acpi_irq_pci_sharing_penalty(int irq)
456{
457 struct acpi_pci_link *link;
458 int penalty = 0;
459 int i;
460
461 list_for_each_entry(link, &acpi_link_list, list) {
462 /*
463 * If a link is active, penalize its IRQ heavily
464 * so we try to choose a different IRQ.
465 */
466 if (link->irq.active && link->irq.active == irq)
467 penalty += PIRQ_PENALTY_PCI_USING;
468
469 /*
470 * penalize the IRQs PCI might use, but not as severely.
471 */
472 for (i = 0; i < link->irq.possible_count; i++)
473 if (link->irq.possible[i] == irq)
474 penalty += PIRQ_PENALTY_PCI_POSSIBLE /
475 link->irq.possible_count;
476 }
477
478 return penalty;
479}
480
481static int acpi_irq_get_penalty(int irq)
482{
483 int penalty = 0;
484
485 if (irq == sci_irq)
486 penalty += sci_penalty;
487
488 if (irq < ACPI_MAX_ISA_IRQS)
489 return penalty + acpi_isa_irq_penalty[irq];
490
491 return penalty + acpi_irq_pci_sharing_penalty(irq);
492}
493
494int __init acpi_irq_penalty_init(void)
495{
496 struct acpi_pci_link *link;
497 int i;
498
499 /*
500 * Update penalties to facilitate IRQ balancing.
501 */
502 list_for_each_entry(link, &acpi_link_list, list) {
503
504 /*
505 * reflect the possible and active irqs in the penalty table --
506 * useful for breaking ties.
507 */
508 if (link->irq.possible_count) {
509 int penalty =
510 PIRQ_PENALTY_PCI_POSSIBLE /
511 link->irq.possible_count;
512
513 for (i = 0; i < link->irq.possible_count; i++) {
514 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
515 acpi_isa_irq_penalty[link->irq.
516 possible[i]] +=
517 penalty;
518 }
519
520 } else if (link->irq.active &&
521 (link->irq.active < ACPI_MAX_ISA_IRQS)) {
522 acpi_isa_irq_penalty[link->irq.active] +=
523 PIRQ_PENALTY_PCI_POSSIBLE;
524 }
525 }
526
527 return 0;
528}
529
530static int acpi_irq_balance = -1; /* 0: static, 1: balance */
531
532static int acpi_pci_link_allocate(struct acpi_pci_link *link)
533{
534 int irq;
535 int i;
536
537 if (link->irq.initialized) {
538 if (link->refcnt == 0)
539 /* This means the link is disabled but initialized */
540 acpi_pci_link_set(link, link->irq.active);
541 return 0;
542 }
543
544 /*
545 * search for active IRQ in list of possible IRQs.
546 */
547 for (i = 0; i < link->irq.possible_count; ++i) {
548 if (link->irq.active == link->irq.possible[i])
549 break;
550 }
551 /*
552 * forget active IRQ that is not in possible list
553 */
554 if (i == link->irq.possible_count) {
555 if (acpi_strict)
556 printk(KERN_WARNING PREFIX "_CRS %d not found"
557 " in _PRS\n", link->irq.active);
558 link->irq.active = 0;
559 }
560
561 /*
562 * if active found, use it; else pick entry from end of possible list.
563 */
564 if (link->irq.active)
565 irq = link->irq.active;
566 else
567 irq = link->irq.possible[link->irq.possible_count - 1];
568
569 if (acpi_irq_balance || !link->irq.active) {
570 /*
571 * Select the best IRQ. This is done in reverse to promote
572 * the use of IRQs 9, 10, 11, and >15.
573 */
574 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
575 if (acpi_irq_get_penalty(irq) >
576 acpi_irq_get_penalty(link->irq.possible[i]))
577 irq = link->irq.possible[i];
578 }
579 }
580 if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
581 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
582 "Try pci=noacpi or acpi=off\n",
583 acpi_device_name(link->device),
584 acpi_device_bid(link->device));
585 return -ENODEV;
586 }
587
588 /* Attempt to enable the link device at this IRQ. */
589 if (acpi_pci_link_set(link, irq)) {
590 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
591 "Try pci=noacpi or acpi=off\n",
592 acpi_device_name(link->device),
593 acpi_device_bid(link->device));
594 return -ENODEV;
595 } else {
596 if (link->irq.active < ACPI_MAX_ISA_IRQS)
597 acpi_isa_irq_penalty[link->irq.active] +=
598 PIRQ_PENALTY_PCI_USING;
599
600 pr_info("%s [%s] enabled at IRQ %d\n",
601 acpi_device_name(link->device),
602 acpi_device_bid(link->device), link->irq.active);
603 }
604
605 link->irq.initialized = 1;
606 return 0;
607}
608
609/*
610 * acpi_pci_link_allocate_irq
611 * success: return IRQ >= 0
612 * failure: return -1
613 */
614int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
615 int *polarity, char **name)
616{
617 int result;
618 struct acpi_device *device;
619 struct acpi_pci_link *link;
620
621 result = acpi_bus_get_device(handle, &device);
622 if (result) {
623 printk(KERN_ERR PREFIX "Invalid link device\n");
624 return -1;
625 }
626
627 link = acpi_driver_data(device);
628 if (!link) {
629 printk(KERN_ERR PREFIX "Invalid link context\n");
630 return -1;
631 }
632
633 /* TBD: Support multiple index (IRQ) entries per Link Device */
634 if (index) {
635 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
636 return -1;
637 }
638
639 mutex_lock(&acpi_link_lock);
640 if (acpi_pci_link_allocate(link)) {
641 mutex_unlock(&acpi_link_lock);
642 return -1;
643 }
644
645 if (!link->irq.active) {
646 mutex_unlock(&acpi_link_lock);
647 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
648 return -1;
649 }
650 link->refcnt++;
651 mutex_unlock(&acpi_link_lock);
652
653 if (triggering)
654 *triggering = link->irq.triggering;
655 if (polarity)
656 *polarity = link->irq.polarity;
657 if (name)
658 *name = acpi_device_bid(link->device);
659 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
660 "Link %s is referenced\n",
661 acpi_device_bid(link->device)));
662 return link->irq.active;
663}
664
665/*
666 * We don't change link's irq information here. After it is reenabled, we
667 * continue use the info
668 */
669int acpi_pci_link_free_irq(acpi_handle handle)
670{
671 struct acpi_device *device;
672 struct acpi_pci_link *link;
673 acpi_status result;
674
675 result = acpi_bus_get_device(handle, &device);
676 if (result) {
677 printk(KERN_ERR PREFIX "Invalid link device\n");
678 return -1;
679 }
680
681 link = acpi_driver_data(device);
682 if (!link) {
683 printk(KERN_ERR PREFIX "Invalid link context\n");
684 return -1;
685 }
686
687 mutex_lock(&acpi_link_lock);
688 if (!link->irq.initialized) {
689 mutex_unlock(&acpi_link_lock);
690 printk(KERN_ERR PREFIX "Link isn't initialized\n");
691 return -1;
692 }
693#ifdef FUTURE_USE
694 /*
695 * The Link reference count allows us to _DISable an unused link
696 * and suspend time, and set it again on resume.
697 * However, 2.6.12 still has irq_router.resume
698 * which blindly restores the link state.
699 * So we disable the reference count method
700 * to prevent duplicate acpi_pci_link_set()
701 * which would harm some systems
702 */
703 link->refcnt--;
704#endif
705 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
706 "Link %s is dereferenced\n",
707 acpi_device_bid(link->device)));
708
709 if (link->refcnt == 0)
710 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
711
712 mutex_unlock(&acpi_link_lock);
713 return link->irq.active;
714}
715
716/* --------------------------------------------------------------------------
717 Driver Interface
718 -------------------------------------------------------------------------- */
719
720static int acpi_pci_link_add(struct acpi_device *device,
721 const struct acpi_device_id *not_used)
722{
723 int result;
724 struct acpi_pci_link *link;
725 int i;
726 int found = 0;
727
728 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
729 if (!link)
730 return -ENOMEM;
731
732 link->device = device;
733 strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
734 strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
735 device->driver_data = link;
736
737 mutex_lock(&acpi_link_lock);
738 result = acpi_pci_link_get_possible(link);
739 if (result)
740 goto end;
741
742 /* query and set link->irq.active */
743 acpi_pci_link_get_current(link);
744
745 printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
746 acpi_device_bid(device));
747 for (i = 0; i < link->irq.possible_count; i++) {
748 if (link->irq.active == link->irq.possible[i]) {
749 printk(KERN_CONT " *%d", link->irq.possible[i]);
750 found = 1;
751 } else
752 printk(KERN_CONT " %d", link->irq.possible[i]);
753 }
754
755 printk(KERN_CONT ")");
756
757 if (!found)
758 printk(KERN_CONT " *%d", link->irq.active);
759
760 if (!link->device->status.enabled)
761 printk(KERN_CONT ", disabled.");
762
763 printk(KERN_CONT "\n");
764
765 list_add_tail(&link->list, &acpi_link_list);
766
767 end:
768 /* disable all links -- to be activated on use */
769 acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
770 mutex_unlock(&acpi_link_lock);
771
772 if (result)
773 kfree(link);
774
775 return result < 0 ? result : 1;
776}
777
778static int acpi_pci_link_resume(struct acpi_pci_link *link)
779{
780 if (link->refcnt && link->irq.active && link->irq.initialized)
781 return (acpi_pci_link_set(link, link->irq.active));
782
783 return 0;
784}
785
786static void irqrouter_resume(void)
787{
788 struct acpi_pci_link *link;
789
790 list_for_each_entry(link, &acpi_link_list, list) {
791 acpi_pci_link_resume(link);
792 }
793}
794
795static void acpi_pci_link_remove(struct acpi_device *device)
796{
797 struct acpi_pci_link *link;
798
799 link = acpi_driver_data(device);
800
801 mutex_lock(&acpi_link_lock);
802 list_del(&link->list);
803 mutex_unlock(&acpi_link_lock);
804
805 kfree(link);
806}
807
808/*
809 * modify acpi_isa_irq_penalty[] from cmdline
810 */
811static int __init acpi_irq_penalty_update(char *str, int used)
812{
813 int i;
814
815 for (i = 0; i < 16; i++) {
816 int retval;
817 int irq;
818 int new_penalty;
819
820 retval = get_option(&str, &irq);
821
822 if (!retval)
823 break; /* no number found */
824
825 /* see if this is a ISA IRQ */
826 if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
827 continue;
828
829 if (used)
830 new_penalty = acpi_isa_irq_penalty[irq] +
831 PIRQ_PENALTY_ISA_USED;
832 else
833 new_penalty = 0;
834
835 acpi_isa_irq_penalty[irq] = new_penalty;
836 if (retval != 2) /* no next number */
837 break;
838 }
839 return 1;
840}
841
842/*
843 * We'd like PNP to call this routine for the
844 * single ISA_USED value for each legacy device.
845 * But instead it calls us with each POSSIBLE setting.
846 * There is no ISA_POSSIBLE weight, so we simply use
847 * the (small) PCI_USING penalty.
848 */
849void acpi_penalize_isa_irq(int irq, int active)
850{
851 if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
852 acpi_isa_irq_penalty[irq] +=
853 (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
854}
855
856bool acpi_isa_irq_available(int irq)
857{
858 return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
859 acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
860}
861
862void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
863{
864 sci_irq = irq;
865
866 if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
867 polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
868 sci_penalty = PIRQ_PENALTY_PCI_USING;
869 else
870 sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
871}
872
873/*
874 * Over-ride default table to reserve additional IRQs for use by ISA
875 * e.g. acpi_irq_isa=5
876 * Useful for telling ACPI how not to interfere with your ISA sound card.
877 */
878static int __init acpi_irq_isa(char *str)
879{
880 return acpi_irq_penalty_update(str, 1);
881}
882
883__setup("acpi_irq_isa=", acpi_irq_isa);
884
885/*
886 * Over-ride default table to free additional IRQs for use by PCI
887 * e.g. acpi_irq_pci=7,15
888 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
889 */
890static int __init acpi_irq_pci(char *str)
891{
892 return acpi_irq_penalty_update(str, 0);
893}
894
895__setup("acpi_irq_pci=", acpi_irq_pci);
896
897static int __init acpi_irq_nobalance_set(char *str)
898{
899 acpi_irq_balance = 0;
900 return 1;
901}
902
903__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
904
905static int __init acpi_irq_balance_set(char *str)
906{
907 acpi_irq_balance = 1;
908 return 1;
909}
910
911__setup("acpi_irq_balance", acpi_irq_balance_set);
912
913static struct syscore_ops irqrouter_syscore_ops = {
914 .resume = irqrouter_resume,
915};
916
917void __init acpi_pci_link_init(void)
918{
919 if (acpi_noirq)
920 return;
921
922 if (acpi_irq_balance == -1) {
923 /* no command line switch: enable balancing in IOAPIC mode */
924 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
925 acpi_irq_balance = 1;
926 else
927 acpi_irq_balance = 0;
928 }
929 register_syscore_ops(&irqrouter_syscore_ops);
930 acpi_scan_add_handler(&pci_link_handler);
931}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
8 *
9 * TBD:
10 * 1. Support more than one IRQ resource entry per link device (index).
11 * 2. Implement start/stop mechanism and use ACPI Bus Driver facilities
12 * for IRQ management (e.g. start()->_SRS).
13 */
14
15#include <linux/syscore_ops.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/types.h>
20#include <linux/spinlock.h>
21#include <linux/pm.h>
22#include <linux/pci.h>
23#include <linux/mutex.h>
24#include <linux/slab.h>
25#include <linux/acpi.h>
26#include <linux/irq.h>
27
28#include "internal.h"
29
30#define _COMPONENT ACPI_PCI_COMPONENT
31ACPI_MODULE_NAME("pci_link");
32#define ACPI_PCI_LINK_CLASS "pci_irq_routing"
33#define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
34#define ACPI_PCI_LINK_FILE_INFO "info"
35#define ACPI_PCI_LINK_FILE_STATUS "state"
36#define ACPI_PCI_LINK_MAX_POSSIBLE 16
37
38static int acpi_pci_link_add(struct acpi_device *device,
39 const struct acpi_device_id *not_used);
40static void acpi_pci_link_remove(struct acpi_device *device);
41
42static const struct acpi_device_id link_device_ids[] = {
43 {"PNP0C0F", 0},
44 {"", 0},
45};
46
47static struct acpi_scan_handler pci_link_handler = {
48 .ids = link_device_ids,
49 .attach = acpi_pci_link_add,
50 .detach = acpi_pci_link_remove,
51};
52
53/*
54 * If a link is initialized, we never change its active and initialized
55 * later even the link is disable. Instead, we just repick the active irq
56 */
57struct acpi_pci_link_irq {
58 u32 active; /* Current IRQ */
59 u8 triggering; /* All IRQs */
60 u8 polarity; /* All IRQs */
61 u8 resource_type;
62 u8 possible_count;
63 u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
64 u8 initialized:1;
65 u8 reserved:7;
66};
67
68struct acpi_pci_link {
69 struct list_head list;
70 struct acpi_device *device;
71 struct acpi_pci_link_irq irq;
72 int refcnt;
73};
74
75static LIST_HEAD(acpi_link_list);
76static DEFINE_MUTEX(acpi_link_lock);
77static int sci_irq = -1, sci_penalty;
78
79/* --------------------------------------------------------------------------
80 PCI Link Device Management
81 -------------------------------------------------------------------------- */
82
83/*
84 * set context (link) possible list from resource list
85 */
86static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
87 void *context)
88{
89 struct acpi_pci_link *link = context;
90 u32 i;
91
92 switch (resource->type) {
93 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
94 case ACPI_RESOURCE_TYPE_END_TAG:
95 return AE_OK;
96 case ACPI_RESOURCE_TYPE_IRQ:
97 {
98 struct acpi_resource_irq *p = &resource->data.irq;
99 if (!p || !p->interrupt_count) {
100 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
101 "Blank _PRS IRQ resource\n"));
102 return AE_OK;
103 }
104 for (i = 0;
105 (i < p->interrupt_count
106 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
107 if (!p->interrupts[i]) {
108 printk(KERN_WARNING PREFIX
109 "Invalid _PRS IRQ %d\n",
110 p->interrupts[i]);
111 continue;
112 }
113 link->irq.possible[i] = p->interrupts[i];
114 link->irq.possible_count++;
115 }
116 link->irq.triggering = p->triggering;
117 link->irq.polarity = p->polarity;
118 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
119 break;
120 }
121 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
122 {
123 struct acpi_resource_extended_irq *p =
124 &resource->data.extended_irq;
125 if (!p || !p->interrupt_count) {
126 printk(KERN_WARNING PREFIX
127 "Blank _PRS EXT IRQ resource\n");
128 return AE_OK;
129 }
130 for (i = 0;
131 (i < p->interrupt_count
132 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
133 if (!p->interrupts[i]) {
134 printk(KERN_WARNING PREFIX
135 "Invalid _PRS IRQ %d\n",
136 p->interrupts[i]);
137 continue;
138 }
139 link->irq.possible[i] = p->interrupts[i];
140 link->irq.possible_count++;
141 }
142 link->irq.triggering = p->triggering;
143 link->irq.polarity = p->polarity;
144 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
145 break;
146 }
147 default:
148 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
149 resource->type);
150 return AE_OK;
151 }
152
153 return AE_CTRL_TERMINATE;
154}
155
156static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
157{
158 acpi_status status;
159
160 status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
161 acpi_pci_link_check_possible, link);
162 if (ACPI_FAILURE(status)) {
163 acpi_handle_debug(link->device->handle, "_PRS not present or invalid");
164 return 0;
165 }
166
167 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
168 "Found %d possible IRQs\n",
169 link->irq.possible_count));
170
171 return 0;
172}
173
174static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
175 void *context)
176{
177 int *irq = context;
178
179 switch (resource->type) {
180 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
181 case ACPI_RESOURCE_TYPE_END_TAG:
182 return AE_OK;
183 case ACPI_RESOURCE_TYPE_IRQ:
184 {
185 struct acpi_resource_irq *p = &resource->data.irq;
186 if (!p || !p->interrupt_count) {
187 /*
188 * IRQ descriptors may have no IRQ# bits set,
189 * particularly those those w/ _STA disabled
190 */
191 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
192 "Blank _CRS IRQ resource\n"));
193 return AE_OK;
194 }
195 *irq = p->interrupts[0];
196 break;
197 }
198 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
199 {
200 struct acpi_resource_extended_irq *p =
201 &resource->data.extended_irq;
202 if (!p || !p->interrupt_count) {
203 /*
204 * extended IRQ descriptors must
205 * return at least 1 IRQ
206 */
207 printk(KERN_WARNING PREFIX
208 "Blank _CRS EXT IRQ resource\n");
209 return AE_OK;
210 }
211 *irq = p->interrupts[0];
212 break;
213 }
214 break;
215 default:
216 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
217 resource->type);
218 return AE_OK;
219 }
220
221 return AE_CTRL_TERMINATE;
222}
223
224/*
225 * Run _CRS and set link->irq.active
226 *
227 * return value:
228 * 0 - success
229 * !0 - failure
230 */
231static int acpi_pci_link_get_current(struct acpi_pci_link *link)
232{
233 int result = 0;
234 acpi_status status;
235 int irq = 0;
236
237 link->irq.active = 0;
238
239 /* in practice, status disabled is meaningless, ignore it */
240 if (acpi_strict) {
241 /* Query _STA, set link->device->status */
242 result = acpi_bus_get_status(link->device);
243 if (result) {
244 printk(KERN_ERR PREFIX "Unable to read status\n");
245 goto end;
246 }
247
248 if (!link->device->status.enabled) {
249 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
250 return 0;
251 }
252 }
253
254 /*
255 * Query and parse _CRS to get the current IRQ assignment.
256 */
257
258 status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
259 acpi_pci_link_check_current, &irq);
260 if (ACPI_FAILURE(status)) {
261 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
262 result = -ENODEV;
263 goto end;
264 }
265
266 if (acpi_strict && !irq) {
267 printk(KERN_ERR PREFIX "_CRS returned 0\n");
268 result = -ENODEV;
269 }
270
271 link->irq.active = irq;
272
273 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
274
275 end:
276 return result;
277}
278
279static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
280{
281 int result;
282 acpi_status status;
283 struct {
284 struct acpi_resource res;
285 struct acpi_resource end;
286 } *resource;
287 struct acpi_buffer buffer = { 0, NULL };
288
289 if (!irq)
290 return -EINVAL;
291
292 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
293 if (!resource)
294 return -ENOMEM;
295
296 buffer.length = sizeof(*resource) + 1;
297 buffer.pointer = resource;
298
299 switch (link->irq.resource_type) {
300 case ACPI_RESOURCE_TYPE_IRQ:
301 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
302 resource->res.length = sizeof(struct acpi_resource);
303 resource->res.data.irq.triggering = link->irq.triggering;
304 resource->res.data.irq.polarity =
305 link->irq.polarity;
306 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
307 resource->res.data.irq.shareable =
308 ACPI_EXCLUSIVE;
309 else
310 resource->res.data.irq.shareable = ACPI_SHARED;
311 resource->res.data.irq.interrupt_count = 1;
312 resource->res.data.irq.interrupts[0] = irq;
313 break;
314
315 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
316 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
317 resource->res.length = sizeof(struct acpi_resource);
318 resource->res.data.extended_irq.producer_consumer =
319 ACPI_CONSUMER;
320 resource->res.data.extended_irq.triggering =
321 link->irq.triggering;
322 resource->res.data.extended_irq.polarity =
323 link->irq.polarity;
324 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
325 resource->res.data.irq.shareable =
326 ACPI_EXCLUSIVE;
327 else
328 resource->res.data.irq.shareable = ACPI_SHARED;
329 resource->res.data.extended_irq.interrupt_count = 1;
330 resource->res.data.extended_irq.interrupts[0] = irq;
331 /* ignore resource_source, it's optional */
332 break;
333 default:
334 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
335 result = -EINVAL;
336 goto end;
337
338 }
339 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
340 resource->end.length = sizeof(struct acpi_resource);
341
342 /* Attempt to set the resource */
343 status = acpi_set_current_resources(link->device->handle, &buffer);
344
345 /* check for total failure */
346 if (ACPI_FAILURE(status)) {
347 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
348 result = -ENODEV;
349 goto end;
350 }
351
352 /* Query _STA, set device->status */
353 result = acpi_bus_get_status(link->device);
354 if (result) {
355 printk(KERN_ERR PREFIX "Unable to read status\n");
356 goto end;
357 }
358 if (!link->device->status.enabled) {
359 printk(KERN_WARNING PREFIX
360 "%s [%s] disabled and referenced, BIOS bug\n",
361 acpi_device_name(link->device),
362 acpi_device_bid(link->device));
363 }
364
365 /* Query _CRS, set link->irq.active */
366 result = acpi_pci_link_get_current(link);
367 if (result) {
368 goto end;
369 }
370
371 /*
372 * Is current setting not what we set?
373 * set link->irq.active
374 */
375 if (link->irq.active != irq) {
376 /*
377 * policy: when _CRS doesn't return what we just _SRS
378 * assume _SRS worked and override _CRS value.
379 */
380 printk(KERN_WARNING PREFIX
381 "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
382 acpi_device_name(link->device),
383 acpi_device_bid(link->device), link->irq.active, irq);
384 link->irq.active = irq;
385 }
386
387 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
388
389 end:
390 kfree(resource);
391 return result;
392}
393
394/* --------------------------------------------------------------------------
395 PCI Link IRQ Management
396 -------------------------------------------------------------------------- */
397
398/*
399 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
400 * Link Devices to move the PIRQs around to minimize sharing.
401 *
402 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
403 * that the BIOS has already set to active. This is necessary because
404 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
405 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
406 * even if acpi_irq_nobalance is set.
407 *
408 * A tables of penalties avoids directing PCI interrupts to well known
409 * ISA IRQs. Boot params are available to over-ride the default table:
410 *
411 * List interrupts that are free for PCI use.
412 * acpi_irq_pci=n[,m]
413 *
414 * List interrupts that should not be used for PCI:
415 * acpi_irq_isa=n[,m]
416 *
417 * Note that PCI IRQ routers have a list of possible IRQs,
418 * which may not include the IRQs this table says are available.
419 *
420 * Since this heuristic can't tell the difference between a link
421 * that no device will attach to, vs. a link which may be shared
422 * by multiple active devices -- it is not optimal.
423 *
424 * If interrupt performance is that important, get an IO-APIC system
425 * with a pin dedicated to each device. Or for that matter, an MSI
426 * enabled system.
427 */
428
429#define ACPI_MAX_ISA_IRQS 16
430
431#define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
432#define PIRQ_PENALTY_PCI_USING (16*16*16)
433#define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
434#define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
435#define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
436
437static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = {
438 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
439 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
440 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
441 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
442 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
443 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
444 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
445 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
446 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
447 0, /* IRQ9 PCI, often acpi */
448 0, /* IRQ10 PCI */
449 0, /* IRQ11 PCI */
450 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
451 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
452 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
453 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
454 /* >IRQ15 */
455};
456
457static int acpi_irq_pci_sharing_penalty(int irq)
458{
459 struct acpi_pci_link *link;
460 int penalty = 0;
461 int i;
462
463 list_for_each_entry(link, &acpi_link_list, list) {
464 /*
465 * If a link is active, penalize its IRQ heavily
466 * so we try to choose a different IRQ.
467 */
468 if (link->irq.active && link->irq.active == irq)
469 penalty += PIRQ_PENALTY_PCI_USING;
470
471 /*
472 * penalize the IRQs PCI might use, but not as severely.
473 */
474 for (i = 0; i < link->irq.possible_count; i++)
475 if (link->irq.possible[i] == irq)
476 penalty += PIRQ_PENALTY_PCI_POSSIBLE /
477 link->irq.possible_count;
478 }
479
480 return penalty;
481}
482
483static int acpi_irq_get_penalty(int irq)
484{
485 int penalty = 0;
486
487 if (irq == sci_irq)
488 penalty += sci_penalty;
489
490 if (irq < ACPI_MAX_ISA_IRQS)
491 return penalty + acpi_isa_irq_penalty[irq];
492
493 return penalty + acpi_irq_pci_sharing_penalty(irq);
494}
495
496int __init acpi_irq_penalty_init(void)
497{
498 struct acpi_pci_link *link;
499 int i;
500
501 /*
502 * Update penalties to facilitate IRQ balancing.
503 */
504 list_for_each_entry(link, &acpi_link_list, list) {
505
506 /*
507 * reflect the possible and active irqs in the penalty table --
508 * useful for breaking ties.
509 */
510 if (link->irq.possible_count) {
511 int penalty =
512 PIRQ_PENALTY_PCI_POSSIBLE /
513 link->irq.possible_count;
514
515 for (i = 0; i < link->irq.possible_count; i++) {
516 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
517 acpi_isa_irq_penalty[link->irq.
518 possible[i]] +=
519 penalty;
520 }
521
522 } else if (link->irq.active &&
523 (link->irq.active < ACPI_MAX_ISA_IRQS)) {
524 acpi_isa_irq_penalty[link->irq.active] +=
525 PIRQ_PENALTY_PCI_POSSIBLE;
526 }
527 }
528
529 return 0;
530}
531
532static int acpi_irq_balance = -1; /* 0: static, 1: balance */
533
534static int acpi_pci_link_allocate(struct acpi_pci_link *link)
535{
536 int irq;
537 int i;
538
539 if (link->irq.initialized) {
540 if (link->refcnt == 0)
541 /* This means the link is disabled but initialized */
542 acpi_pci_link_set(link, link->irq.active);
543 return 0;
544 }
545
546 /*
547 * search for active IRQ in list of possible IRQs.
548 */
549 for (i = 0; i < link->irq.possible_count; ++i) {
550 if (link->irq.active == link->irq.possible[i])
551 break;
552 }
553 /*
554 * forget active IRQ that is not in possible list
555 */
556 if (i == link->irq.possible_count) {
557 if (acpi_strict)
558 printk(KERN_WARNING PREFIX "_CRS %d not found"
559 " in _PRS\n", link->irq.active);
560 link->irq.active = 0;
561 }
562
563 /*
564 * if active found, use it; else pick entry from end of possible list.
565 */
566 if (link->irq.active)
567 irq = link->irq.active;
568 else
569 irq = link->irq.possible[link->irq.possible_count - 1];
570
571 if (acpi_irq_balance || !link->irq.active) {
572 /*
573 * Select the best IRQ. This is done in reverse to promote
574 * the use of IRQs 9, 10, 11, and >15.
575 */
576 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
577 if (acpi_irq_get_penalty(irq) >
578 acpi_irq_get_penalty(link->irq.possible[i]))
579 irq = link->irq.possible[i];
580 }
581 }
582 if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
583 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
584 "Try pci=noacpi or acpi=off\n",
585 acpi_device_name(link->device),
586 acpi_device_bid(link->device));
587 return -ENODEV;
588 }
589
590 /* Attempt to enable the link device at this IRQ. */
591 if (acpi_pci_link_set(link, irq)) {
592 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
593 "Try pci=noacpi or acpi=off\n",
594 acpi_device_name(link->device),
595 acpi_device_bid(link->device));
596 return -ENODEV;
597 } else {
598 if (link->irq.active < ACPI_MAX_ISA_IRQS)
599 acpi_isa_irq_penalty[link->irq.active] +=
600 PIRQ_PENALTY_PCI_USING;
601
602 pr_info("%s [%s] enabled at IRQ %d\n",
603 acpi_device_name(link->device),
604 acpi_device_bid(link->device), link->irq.active);
605 }
606
607 link->irq.initialized = 1;
608 return 0;
609}
610
611/*
612 * acpi_pci_link_allocate_irq
613 * success: return IRQ >= 0
614 * failure: return -1
615 */
616int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
617 int *polarity, char **name)
618{
619 int result;
620 struct acpi_device *device;
621 struct acpi_pci_link *link;
622
623 result = acpi_bus_get_device(handle, &device);
624 if (result) {
625 printk(KERN_ERR PREFIX "Invalid link device\n");
626 return -1;
627 }
628
629 link = acpi_driver_data(device);
630 if (!link) {
631 printk(KERN_ERR PREFIX "Invalid link context\n");
632 return -1;
633 }
634
635 /* TBD: Support multiple index (IRQ) entries per Link Device */
636 if (index) {
637 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
638 return -1;
639 }
640
641 mutex_lock(&acpi_link_lock);
642 if (acpi_pci_link_allocate(link)) {
643 mutex_unlock(&acpi_link_lock);
644 return -1;
645 }
646
647 if (!link->irq.active) {
648 mutex_unlock(&acpi_link_lock);
649 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
650 return -1;
651 }
652 link->refcnt++;
653 mutex_unlock(&acpi_link_lock);
654
655 if (triggering)
656 *triggering = link->irq.triggering;
657 if (polarity)
658 *polarity = link->irq.polarity;
659 if (name)
660 *name = acpi_device_bid(link->device);
661 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
662 "Link %s is referenced\n",
663 acpi_device_bid(link->device)));
664 return link->irq.active;
665}
666
667/*
668 * We don't change link's irq information here. After it is reenabled, we
669 * continue use the info
670 */
671int acpi_pci_link_free_irq(acpi_handle handle)
672{
673 struct acpi_device *device;
674 struct acpi_pci_link *link;
675 acpi_status result;
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
722static int acpi_pci_link_add(struct acpi_device *device,
723 const struct acpi_device_id *not_used)
724{
725 int result;
726 struct acpi_pci_link *link;
727 int i;
728 int found = 0;
729
730 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
731 if (!link)
732 return -ENOMEM;
733
734 link->device = device;
735 strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
736 strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
737 device->driver_data = link;
738
739 mutex_lock(&acpi_link_lock);
740 result = acpi_pci_link_get_possible(link);
741 if (result)
742 goto end;
743
744 /* query and set link->irq.active */
745 acpi_pci_link_get_current(link);
746
747 printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
748 acpi_device_bid(device));
749 for (i = 0; i < link->irq.possible_count; i++) {
750 if (link->irq.active == link->irq.possible[i]) {
751 printk(KERN_CONT " *%d", link->irq.possible[i]);
752 found = 1;
753 } else
754 printk(KERN_CONT " %d", link->irq.possible[i]);
755 }
756
757 printk(KERN_CONT ")");
758
759 if (!found)
760 printk(KERN_CONT " *%d", link->irq.active);
761
762 if (!link->device->status.enabled)
763 printk(KERN_CONT ", disabled.");
764
765 printk(KERN_CONT "\n");
766
767 list_add_tail(&link->list, &acpi_link_list);
768
769 end:
770 /* disable all links -- to be activated on use */
771 acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
772 mutex_unlock(&acpi_link_lock);
773
774 if (result)
775 kfree(link);
776
777 return result < 0 ? result : 1;
778}
779
780static int acpi_pci_link_resume(struct acpi_pci_link *link)
781{
782 if (link->refcnt && link->irq.active && link->irq.initialized)
783 return (acpi_pci_link_set(link, link->irq.active));
784
785 return 0;
786}
787
788static void irqrouter_resume(void)
789{
790 struct acpi_pci_link *link;
791
792 list_for_each_entry(link, &acpi_link_list, list) {
793 acpi_pci_link_resume(link);
794 }
795}
796
797static void acpi_pci_link_remove(struct acpi_device *device)
798{
799 struct acpi_pci_link *link;
800
801 link = acpi_driver_data(device);
802
803 mutex_lock(&acpi_link_lock);
804 list_del(&link->list);
805 mutex_unlock(&acpi_link_lock);
806
807 kfree(link);
808}
809
810/*
811 * modify acpi_isa_irq_penalty[] from cmdline
812 */
813static int __init acpi_irq_penalty_update(char *str, int used)
814{
815 int i;
816
817 for (i = 0; i < 16; i++) {
818 int retval;
819 int irq;
820 int new_penalty;
821
822 retval = get_option(&str, &irq);
823
824 if (!retval)
825 break; /* no number found */
826
827 /* see if this is a ISA IRQ */
828 if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
829 continue;
830
831 if (used)
832 new_penalty = acpi_isa_irq_penalty[irq] +
833 PIRQ_PENALTY_ISA_USED;
834 else
835 new_penalty = 0;
836
837 acpi_isa_irq_penalty[irq] = new_penalty;
838 if (retval != 2) /* no next number */
839 break;
840 }
841 return 1;
842}
843
844/*
845 * We'd like PNP to call this routine for the
846 * single ISA_USED value for each legacy device.
847 * But instead it calls us with each POSSIBLE setting.
848 * There is no ISA_POSSIBLE weight, so we simply use
849 * the (small) PCI_USING penalty.
850 */
851void acpi_penalize_isa_irq(int irq, int active)
852{
853 if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
854 acpi_isa_irq_penalty[irq] +=
855 (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
856}
857
858bool acpi_isa_irq_available(int irq)
859{
860 return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
861 acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
862}
863
864void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
865{
866 sci_irq = irq;
867
868 if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
869 polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
870 sci_penalty = PIRQ_PENALTY_PCI_USING;
871 else
872 sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
873}
874
875/*
876 * Over-ride default table to reserve additional IRQs for use by ISA
877 * e.g. acpi_irq_isa=5
878 * Useful for telling ACPI how not to interfere with your ISA sound card.
879 */
880static int __init acpi_irq_isa(char *str)
881{
882 return acpi_irq_penalty_update(str, 1);
883}
884
885__setup("acpi_irq_isa=", acpi_irq_isa);
886
887/*
888 * Over-ride default table to free additional IRQs for use by PCI
889 * e.g. acpi_irq_pci=7,15
890 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
891 */
892static int __init acpi_irq_pci(char *str)
893{
894 return acpi_irq_penalty_update(str, 0);
895}
896
897__setup("acpi_irq_pci=", acpi_irq_pci);
898
899static int __init acpi_irq_nobalance_set(char *str)
900{
901 acpi_irq_balance = 0;
902 return 1;
903}
904
905__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
906
907static int __init acpi_irq_balance_set(char *str)
908{
909 acpi_irq_balance = 1;
910 return 1;
911}
912
913__setup("acpi_irq_balance", acpi_irq_balance_set);
914
915static struct syscore_ops irqrouter_syscore_ops = {
916 .resume = irqrouter_resume,
917};
918
919void __init acpi_pci_link_init(void)
920{
921 if (acpi_noirq)
922 return;
923
924 if (acpi_irq_balance == -1) {
925 /* no command line switch: enable balancing in IOAPIC mode */
926 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
927 acpi_irq_balance = 1;
928 else
929 acpi_irq_balance = 0;
930 }
931 register_syscore_ops(&irqrouter_syscore_ops);
932 acpi_scan_add_handler(&pci_link_handler);
933}