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