2 * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
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>
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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.
24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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).
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>
39 #include <linux/pci.h>
40 #include <linux/mutex.h>
41 #include <linux/slab.h>
43 #include <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
46 #define PREFIX "ACPI: "
48 #define _COMPONENT ACPI_PCI_COMPONENT
49 ACPI_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
56 static int acpi_pci_link_add(struct acpi_device *device,
57 const struct acpi_device_id *not_used);
58 static void acpi_pci_link_remove(struct acpi_device *device);
60 static const struct acpi_device_id link_device_ids[] = {
65 static struct acpi_scan_handler pci_link_handler = {
66 .ids = link_device_ids,
67 .attach = acpi_pci_link_add,
68 .detach = acpi_pci_link_remove,
72 * If a link is initialized, we never change its active and initialized
73 * later even the link is disable. Instead, we just repick the active irq
75 struct acpi_pci_link_irq {
76 u8 active; /* Current IRQ */
77 u8 triggering; /* All IRQs */
78 u8 polarity; /* All IRQs */
81 u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
86 struct acpi_pci_link {
87 struct list_head list;
88 struct acpi_device *device;
89 struct acpi_pci_link_irq irq;
93 static LIST_HEAD(acpi_link_list);
94 static DEFINE_MUTEX(acpi_link_lock);
96 /* --------------------------------------------------------------------------
97 PCI Link Device Management
98 -------------------------------------------------------------------------- */
101 * set context (link) possible list from resource list
103 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
106 struct acpi_pci_link *link = context;
109 switch (resource->type) {
110 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
111 case ACPI_RESOURCE_TYPE_END_TAG:
113 case ACPI_RESOURCE_TYPE_IRQ:
115 struct acpi_resource_irq *p = &resource->data.irq;
116 if (!p || !p->interrupt_count) {
117 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
118 "Blank _PRS IRQ resource\n"));
122 (i < p->interrupt_count
123 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
124 if (!p->interrupts[i]) {
125 printk(KERN_WARNING PREFIX
126 "Invalid _PRS IRQ %d\n",
130 link->irq.possible[i] = p->interrupts[i];
131 link->irq.possible_count++;
133 link->irq.triggering = p->triggering;
134 link->irq.polarity = p->polarity;
135 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
138 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
140 struct acpi_resource_extended_irq *p =
141 &resource->data.extended_irq;
142 if (!p || !p->interrupt_count) {
143 printk(KERN_WARNING PREFIX
144 "Blank _PRS EXT IRQ resource\n");
148 (i < p->interrupt_count
149 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
150 if (!p->interrupts[i]) {
151 printk(KERN_WARNING PREFIX
152 "Invalid _PRS IRQ %d\n",
156 link->irq.possible[i] = p->interrupts[i];
157 link->irq.possible_count++;
159 link->irq.triggering = p->triggering;
160 link->irq.polarity = p->polarity;
161 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
165 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
170 return AE_CTRL_TERMINATE;
173 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
177 status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
178 acpi_pci_link_check_possible, link);
179 if (ACPI_FAILURE(status)) {
180 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
184 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
185 "Found %d possible IRQs\n",
186 link->irq.possible_count));
191 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
196 switch (resource->type) {
197 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
198 case ACPI_RESOURCE_TYPE_END_TAG:
200 case ACPI_RESOURCE_TYPE_IRQ:
202 struct acpi_resource_irq *p = &resource->data.irq;
203 if (!p || !p->interrupt_count) {
205 * IRQ descriptors may have no IRQ# bits set,
206 * particularly those those w/ _STA disabled
208 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
209 "Blank _CRS IRQ resource\n"));
212 *irq = p->interrupts[0];
215 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
217 struct acpi_resource_extended_irq *p =
218 &resource->data.extended_irq;
219 if (!p || !p->interrupt_count) {
221 * extended IRQ descriptors must
222 * return at least 1 IRQ
224 printk(KERN_WARNING PREFIX
225 "Blank _CRS EXT IRQ resource\n");
228 *irq = p->interrupts[0];
233 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
238 return AE_CTRL_TERMINATE;
242 * Run _CRS and set link->irq.active
248 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
254 link->irq.active = 0;
256 /* in practice, status disabled is meaningless, ignore it */
258 /* Query _STA, set link->device->status */
259 result = acpi_bus_get_status(link->device);
261 printk(KERN_ERR PREFIX "Unable to read status\n");
265 if (!link->device->status.enabled) {
266 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
272 * Query and parse _CRS to get the current IRQ assignment.
275 status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
276 acpi_pci_link_check_current, &irq);
277 if (ACPI_FAILURE(status)) {
278 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
283 if (acpi_strict && !irq) {
284 printk(KERN_ERR PREFIX "_CRS returned 0\n");
288 link->irq.active = irq;
290 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
296 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
301 struct acpi_resource res;
302 struct acpi_resource end;
304 struct acpi_buffer buffer = { 0, NULL };
309 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
313 buffer.length = sizeof(*resource) + 1;
314 buffer.pointer = resource;
316 switch (link->irq.resource_type) {
317 case ACPI_RESOURCE_TYPE_IRQ:
318 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
319 resource->res.length = sizeof(struct acpi_resource);
320 resource->res.data.irq.triggering = link->irq.triggering;
321 resource->res.data.irq.polarity =
323 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
324 resource->res.data.irq.sharable =
327 resource->res.data.irq.sharable = ACPI_SHARED;
328 resource->res.data.irq.interrupt_count = 1;
329 resource->res.data.irq.interrupts[0] = irq;
332 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
333 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
334 resource->res.length = sizeof(struct acpi_resource);
335 resource->res.data.extended_irq.producer_consumer =
337 resource->res.data.extended_irq.triggering =
338 link->irq.triggering;
339 resource->res.data.extended_irq.polarity =
341 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
342 resource->res.data.irq.sharable =
345 resource->res.data.irq.sharable = ACPI_SHARED;
346 resource->res.data.extended_irq.interrupt_count = 1;
347 resource->res.data.extended_irq.interrupts[0] = irq;
348 /* ignore resource_source, it's optional */
351 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
356 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
358 /* Attempt to set the resource */
359 status = acpi_set_current_resources(link->device->handle, &buffer);
361 /* check for total failure */
362 if (ACPI_FAILURE(status)) {
363 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
368 /* Query _STA, set device->status */
369 result = acpi_bus_get_status(link->device);
371 printk(KERN_ERR PREFIX "Unable to read status\n");
374 if (!link->device->status.enabled) {
375 printk(KERN_WARNING PREFIX
376 "%s [%s] disabled and referenced, BIOS bug\n",
377 acpi_device_name(link->device),
378 acpi_device_bid(link->device));
381 /* Query _CRS, set link->irq.active */
382 result = acpi_pci_link_get_current(link);
388 * Is current setting not what we set?
389 * set link->irq.active
391 if (link->irq.active != irq) {
393 * policy: when _CRS doesn't return what we just _SRS
394 * assume _SRS worked and override _CRS value.
396 printk(KERN_WARNING PREFIX
397 "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
398 acpi_device_name(link->device),
399 acpi_device_bid(link->device), link->irq.active, irq);
400 link->irq.active = irq;
403 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
410 /* --------------------------------------------------------------------------
411 PCI Link IRQ Management
412 -------------------------------------------------------------------------- */
415 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
416 * Link Devices to move the PIRQs around to minimize sharing.
418 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
419 * that the BIOS has already set to active. This is necessary because
420 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
421 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
422 * even if acpi_irq_nobalance is set.
424 * A tables of penalties avoids directing PCI interrupts to well known
425 * ISA IRQs. Boot params are available to over-ride the default table:
427 * List interrupts that are free for PCI use.
430 * List interrupts that should not be used for PCI:
433 * Note that PCI IRQ routers have a list of possible IRQs,
434 * which may not include the IRQs this table says are available.
436 * Since this heuristic can't tell the difference between a link
437 * that no device will attach to, vs. a link which may be shared
438 * by multiple active devices -- it is not optimal.
440 * If interrupt performance is that important, get an IO-APIC system
441 * with a pin dedicated to each device. Or for that matter, an MSI
445 #define ACPI_MAX_IRQS 256
446 #define ACPI_MAX_ISA_IRQ 16
448 #define PIRQ_PENALTY_PCI_AVAILABLE (0)
449 #define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
450 #define PIRQ_PENALTY_PCI_USING (16*16*16)
451 #define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
452 #define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
453 #define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
455 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
456 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
457 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
458 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
459 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
460 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
461 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
462 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
463 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
464 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
465 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ9 PCI, often acpi */
466 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ10 PCI */
467 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ11 PCI */
468 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
469 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
470 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
471 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
475 int __init acpi_irq_penalty_init(void)
477 struct acpi_pci_link *link;
481 * Update penalties to facilitate IRQ balancing.
483 list_for_each_entry(link, &acpi_link_list, list) {
486 * reflect the possible and active irqs in the penalty table --
487 * useful for breaking ties.
489 if (link->irq.possible_count) {
491 PIRQ_PENALTY_PCI_POSSIBLE /
492 link->irq.possible_count;
494 for (i = 0; i < link->irq.possible_count; i++) {
495 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
496 acpi_irq_penalty[link->irq.
501 } else if (link->irq.active) {
502 acpi_irq_penalty[link->irq.active] +=
503 PIRQ_PENALTY_PCI_POSSIBLE;
506 /* Add a penalty for the SCI */
507 acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
511 static int acpi_irq_balance = -1; /* 0: static, 1: balance */
513 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
518 if (link->irq.initialized) {
519 if (link->refcnt == 0)
520 /* This means the link is disabled but initialized */
521 acpi_pci_link_set(link, link->irq.active);
526 * search for active IRQ in list of possible IRQs.
528 for (i = 0; i < link->irq.possible_count; ++i) {
529 if (link->irq.active == link->irq.possible[i])
533 * forget active IRQ that is not in possible list
535 if (i == link->irq.possible_count) {
537 printk(KERN_WARNING PREFIX "_CRS %d not found"
538 " in _PRS\n", link->irq.active);
539 link->irq.active = 0;
543 * if active found, use it; else pick entry from end of possible list.
545 if (link->irq.active)
546 irq = link->irq.active;
548 irq = link->irq.possible[link->irq.possible_count - 1];
550 if (acpi_irq_balance || !link->irq.active) {
552 * Select the best IRQ. This is done in reverse to promote
553 * the use of IRQs 9, 10, 11, and >15.
555 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
556 if (acpi_irq_penalty[irq] >
557 acpi_irq_penalty[link->irq.possible[i]])
558 irq = link->irq.possible[i];
562 /* Attempt to enable the link device at this IRQ. */
563 if (acpi_pci_link_set(link, irq)) {
564 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
565 "Try pci=noacpi or acpi=off\n",
566 acpi_device_name(link->device),
567 acpi_device_bid(link->device));
570 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
571 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
572 acpi_device_name(link->device),
573 acpi_device_bid(link->device), link->irq.active);
576 link->irq.initialized = 1;
581 * acpi_pci_link_allocate_irq
582 * success: return IRQ >= 0
585 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
586 int *polarity, char **name)
589 struct acpi_device *device;
590 struct acpi_pci_link *link;
592 result = acpi_bus_get_device(handle, &device);
594 printk(KERN_ERR PREFIX "Invalid link device\n");
598 link = acpi_driver_data(device);
600 printk(KERN_ERR PREFIX "Invalid link context\n");
604 /* TBD: Support multiple index (IRQ) entries per Link Device */
606 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
610 mutex_lock(&acpi_link_lock);
611 if (acpi_pci_link_allocate(link)) {
612 mutex_unlock(&acpi_link_lock);
616 if (!link->irq.active) {
617 mutex_unlock(&acpi_link_lock);
618 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
622 mutex_unlock(&acpi_link_lock);
625 *triggering = link->irq.triggering;
627 *polarity = link->irq.polarity;
629 *name = acpi_device_bid(link->device);
630 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
631 "Link %s is referenced\n",
632 acpi_device_bid(link->device)));
633 return (link->irq.active);
637 * We don't change link's irq information here. After it is reenabled, we
638 * continue use the info
640 int acpi_pci_link_free_irq(acpi_handle handle)
642 struct acpi_device *device;
643 struct acpi_pci_link *link;
646 result = acpi_bus_get_device(handle, &device);
648 printk(KERN_ERR PREFIX "Invalid link device\n");
652 link = acpi_driver_data(device);
654 printk(KERN_ERR PREFIX "Invalid link context\n");
658 mutex_lock(&acpi_link_lock);
659 if (!link->irq.initialized) {
660 mutex_unlock(&acpi_link_lock);
661 printk(KERN_ERR PREFIX "Link isn't initialized\n");
666 * The Link reference count allows us to _DISable an unused link
667 * and suspend time, and set it again on resume.
668 * However, 2.6.12 still has irq_router.resume
669 * which blindly restores the link state.
670 * So we disable the reference count method
671 * to prevent duplicate acpi_pci_link_set()
672 * which would harm some systems
676 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
677 "Link %s is dereferenced\n",
678 acpi_device_bid(link->device)));
680 if (link->refcnt == 0)
681 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
683 mutex_unlock(&acpi_link_lock);
684 return (link->irq.active);
687 /* --------------------------------------------------------------------------
689 -------------------------------------------------------------------------- */
691 static int acpi_pci_link_add(struct acpi_device *device,
692 const struct acpi_device_id *not_used)
695 struct acpi_pci_link *link;
699 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
703 link->device = device;
704 strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
705 strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
706 device->driver_data = link;
708 mutex_lock(&acpi_link_lock);
709 result = acpi_pci_link_get_possible(link);
713 /* query and set link->irq.active */
714 acpi_pci_link_get_current(link);
716 printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
717 acpi_device_bid(device));
718 for (i = 0; i < link->irq.possible_count; i++) {
719 if (link->irq.active == link->irq.possible[i]) {
720 printk(KERN_CONT " *%d", link->irq.possible[i]);
723 printk(KERN_CONT " %d", link->irq.possible[i]);
726 printk(KERN_CONT ")");
729 printk(KERN_CONT " *%d", link->irq.active);
731 if (!link->device->status.enabled)
732 printk(KERN_CONT ", disabled.");
734 printk(KERN_CONT "\n");
736 list_add_tail(&link->list, &acpi_link_list);
739 /* disable all links -- to be activated on use */
740 acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
741 mutex_unlock(&acpi_link_lock);
746 return result < 0 ? result : 1;
749 static int acpi_pci_link_resume(struct acpi_pci_link *link)
751 if (link->refcnt && link->irq.active && link->irq.initialized)
752 return (acpi_pci_link_set(link, link->irq.active));
757 static void irqrouter_resume(void)
759 struct acpi_pci_link *link;
761 list_for_each_entry(link, &acpi_link_list, list) {
762 acpi_pci_link_resume(link);
766 static void acpi_pci_link_remove(struct acpi_device *device)
768 struct acpi_pci_link *link;
770 link = acpi_driver_data(device);
772 mutex_lock(&acpi_link_lock);
773 list_del(&link->list);
774 mutex_unlock(&acpi_link_lock);
780 * modify acpi_irq_penalty[] from cmdline
782 static int __init acpi_irq_penalty_update(char *str, int used)
786 for (i = 0; i < 16; i++) {
790 retval = get_option(&str, &irq);
793 break; /* no number found */
798 if (irq >= ARRAY_SIZE(acpi_irq_penalty))
802 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
804 acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
806 if (retval != 2) /* no next number */
813 * We'd like PNP to call this routine for the
814 * single ISA_USED value for each legacy device.
815 * But instead it calls us with each POSSIBLE setting.
816 * There is no ISA_POSSIBLE weight, so we simply use
817 * the (small) PCI_USING penalty.
819 void acpi_penalize_isa_irq(int irq, int active)
821 if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
823 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
825 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
830 * Over-ride default table to reserve additional IRQs for use by ISA
831 * e.g. acpi_irq_isa=5
832 * Useful for telling ACPI how not to interfere with your ISA sound card.
834 static int __init acpi_irq_isa(char *str)
836 return acpi_irq_penalty_update(str, 1);
839 __setup("acpi_irq_isa=", acpi_irq_isa);
842 * Over-ride default table to free additional IRQs for use by PCI
843 * e.g. acpi_irq_pci=7,15
844 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
846 static int __init acpi_irq_pci(char *str)
848 return acpi_irq_penalty_update(str, 0);
851 __setup("acpi_irq_pci=", acpi_irq_pci);
853 static int __init acpi_irq_nobalance_set(char *str)
855 acpi_irq_balance = 0;
859 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
861 static int __init acpi_irq_balance_set(char *str)
863 acpi_irq_balance = 1;
867 __setup("acpi_irq_balance", acpi_irq_balance_set);
869 static struct syscore_ops irqrouter_syscore_ops = {
870 .resume = irqrouter_resume,
873 void __init acpi_pci_link_init(void)
878 if (acpi_irq_balance == -1) {
879 /* no command line switch: enable balancing in IOAPIC mode */
880 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
881 acpi_irq_balance = 1;
883 acpi_irq_balance = 0;
885 register_syscore_ops(&irqrouter_syscore_ops);
886 acpi_scan_add_handler(&pci_link_handler);