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