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/sysdev.h>
33 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/init.h>
36 #include <linux/types.h>
37 #include <linux/proc_fs.h>
38 #include <linux/spinlock.h>
40 #include <linux/pci.h>
41 #include <linux/mutex.h>
42 #include <linux/slab.h>
44 #include <acpi/acpi_bus.h>
45 #include <acpi/acpi_drivers.h>
47 #define PREFIX "ACPI: "
49 #define _COMPONENT ACPI_PCI_COMPONENT
50 ACPI_MODULE_NAME("pci_link");
51 #define ACPI_PCI_LINK_CLASS "pci_irq_routing"
52 #define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
53 #define ACPI_PCI_LINK_FILE_INFO "info"
54 #define ACPI_PCI_LINK_FILE_STATUS "state"
55 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
57 static int acpi_pci_link_add(struct acpi_device *device);
58 static int acpi_pci_link_remove(struct acpi_device *device, int type);
60 static const struct acpi_device_id link_device_ids[] = {
64 MODULE_DEVICE_TABLE(acpi, link_device_ids);
66 static struct acpi_driver acpi_pci_link_driver = {
68 .class = ACPI_PCI_LINK_CLASS,
69 .ids = link_device_ids,
71 .add = acpi_pci_link_add,
72 .remove = acpi_pci_link_remove,
77 * If a link is initialized, we never change its active and initialized
78 * later even the link is disable. Instead, we just repick the active irq
80 struct acpi_pci_link_irq {
81 u8 active; /* Current IRQ */
82 u8 triggering; /* All IRQs */
83 u8 polarity; /* All IRQs */
86 u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
91 struct acpi_pci_link {
92 struct list_head list;
93 struct acpi_device *device;
94 struct acpi_pci_link_irq irq;
98 static LIST_HEAD(acpi_link_list);
99 static DEFINE_MUTEX(acpi_link_lock);
101 /* --------------------------------------------------------------------------
102 PCI Link Device Management
103 -------------------------------------------------------------------------- */
106 * set context (link) possible list from resource list
108 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
111 struct acpi_pci_link *link = context;
114 switch (resource->type) {
115 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
116 case ACPI_RESOURCE_TYPE_END_TAG:
118 case ACPI_RESOURCE_TYPE_IRQ:
120 struct acpi_resource_irq *p = &resource->data.irq;
121 if (!p || !p->interrupt_count) {
122 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
123 "Blank _PRS IRQ resource\n"));
127 (i < p->interrupt_count
128 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
129 if (!p->interrupts[i]) {
130 printk(KERN_WARNING PREFIX
131 "Invalid _PRS IRQ %d\n",
135 link->irq.possible[i] = p->interrupts[i];
136 link->irq.possible_count++;
138 link->irq.triggering = p->triggering;
139 link->irq.polarity = p->polarity;
140 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
143 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
145 struct acpi_resource_extended_irq *p =
146 &resource->data.extended_irq;
147 if (!p || !p->interrupt_count) {
148 printk(KERN_WARNING PREFIX
149 "Blank _PRS EXT IRQ resource\n");
153 (i < p->interrupt_count
154 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
155 if (!p->interrupts[i]) {
156 printk(KERN_WARNING PREFIX
157 "Invalid _PRS IRQ %d\n",
161 link->irq.possible[i] = p->interrupts[i];
162 link->irq.possible_count++;
164 link->irq.triggering = p->triggering;
165 link->irq.polarity = p->polarity;
166 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
170 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
175 return AE_CTRL_TERMINATE;
178 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
182 status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
183 acpi_pci_link_check_possible, link);
184 if (ACPI_FAILURE(status)) {
185 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
189 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
190 "Found %d possible IRQs\n",
191 link->irq.possible_count));
196 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
201 switch (resource->type) {
202 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
203 case ACPI_RESOURCE_TYPE_END_TAG:
205 case ACPI_RESOURCE_TYPE_IRQ:
207 struct acpi_resource_irq *p = &resource->data.irq;
208 if (!p || !p->interrupt_count) {
210 * IRQ descriptors may have no IRQ# bits set,
211 * particularly those those w/ _STA disabled
213 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
214 "Blank _CRS IRQ resource\n"));
217 *irq = p->interrupts[0];
220 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
222 struct acpi_resource_extended_irq *p =
223 &resource->data.extended_irq;
224 if (!p || !p->interrupt_count) {
226 * extended IRQ descriptors must
227 * return at least 1 IRQ
229 printk(KERN_WARNING PREFIX
230 "Blank _CRS EXT IRQ resource\n");
233 *irq = p->interrupts[0];
238 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
243 return AE_CTRL_TERMINATE;
247 * Run _CRS and set link->irq.active
253 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
259 link->irq.active = 0;
261 /* in practice, status disabled is meaningless, ignore it */
263 /* Query _STA, set link->device->status */
264 result = acpi_bus_get_status(link->device);
266 printk(KERN_ERR PREFIX "Unable to read status\n");
270 if (!link->device->status.enabled) {
271 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
277 * Query and parse _CRS to get the current IRQ assignment.
280 status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
281 acpi_pci_link_check_current, &irq);
282 if (ACPI_FAILURE(status)) {
283 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
288 if (acpi_strict && !irq) {
289 printk(KERN_ERR PREFIX "_CRS returned 0\n");
293 link->irq.active = irq;
295 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
301 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
306 struct acpi_resource res;
307 struct acpi_resource end;
309 struct acpi_buffer buffer = { 0, NULL };
314 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
318 buffer.length = sizeof(*resource) + 1;
319 buffer.pointer = resource;
321 switch (link->irq.resource_type) {
322 case ACPI_RESOURCE_TYPE_IRQ:
323 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
324 resource->res.length = sizeof(struct acpi_resource);
325 resource->res.data.irq.triggering = link->irq.triggering;
326 resource->res.data.irq.polarity =
328 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
329 resource->res.data.irq.sharable =
332 resource->res.data.irq.sharable = ACPI_SHARED;
333 resource->res.data.irq.interrupt_count = 1;
334 resource->res.data.irq.interrupts[0] = irq;
337 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
338 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
339 resource->res.length = sizeof(struct acpi_resource);
340 resource->res.data.extended_irq.producer_consumer =
342 resource->res.data.extended_irq.triggering =
343 link->irq.triggering;
344 resource->res.data.extended_irq.polarity =
346 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
347 resource->res.data.irq.sharable =
350 resource->res.data.irq.sharable = ACPI_SHARED;
351 resource->res.data.extended_irq.interrupt_count = 1;
352 resource->res.data.extended_irq.interrupts[0] = irq;
353 /* ignore resource_source, it's optional */
356 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
361 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
363 /* Attempt to set the resource */
364 status = acpi_set_current_resources(link->device->handle, &buffer);
366 /* check for total failure */
367 if (ACPI_FAILURE(status)) {
368 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
373 /* Query _STA, set device->status */
374 result = acpi_bus_get_status(link->device);
376 printk(KERN_ERR PREFIX "Unable to read status\n");
379 if (!link->device->status.enabled) {
380 printk(KERN_WARNING PREFIX
381 "%s [%s] disabled and referenced, BIOS bug\n",
382 acpi_device_name(link->device),
383 acpi_device_bid(link->device));
386 /* Query _CRS, set link->irq.active */
387 result = acpi_pci_link_get_current(link);
393 * Is current setting not what we set?
394 * set link->irq.active
396 if (link->irq.active != irq) {
398 * policy: when _CRS doesn't return what we just _SRS
399 * assume _SRS worked and override _CRS value.
401 printk(KERN_WARNING PREFIX
402 "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
403 acpi_device_name(link->device),
404 acpi_device_bid(link->device), link->irq.active, irq);
405 link->irq.active = irq;
408 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
415 /* --------------------------------------------------------------------------
416 PCI Link IRQ Management
417 -------------------------------------------------------------------------- */
420 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
421 * Link Devices to move the PIRQs around to minimize sharing.
423 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
424 * that the BIOS has already set to active. This is necessary because
425 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
426 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
427 * even if acpi_irq_nobalance is set.
429 * A tables of penalties avoids directing PCI interrupts to well known
430 * ISA IRQs. Boot params are available to over-ride the default table:
432 * List interrupts that are free for PCI use.
435 * List interrupts that should not be used for PCI:
438 * Note that PCI IRQ routers have a list of possible IRQs,
439 * which may not include the IRQs this table says are available.
441 * Since this heuristic can't tell the difference between a link
442 * that no device will attach to, vs. a link which may be shared
443 * by multiple active devices -- it is not optimal.
445 * If interrupt performance is that important, get an IO-APIC system
446 * with a pin dedicated to each device. Or for that matter, an MSI
450 #define ACPI_MAX_IRQS 256
451 #define ACPI_MAX_ISA_IRQ 16
453 #define PIRQ_PENALTY_PCI_AVAILABLE (0)
454 #define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
455 #define PIRQ_PENALTY_PCI_USING (16*16*16)
456 #define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
457 #define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
458 #define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
460 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
461 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
462 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
463 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
464 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
465 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
466 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
467 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
468 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
469 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
470 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ9 PCI, often acpi */
471 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ10 PCI */
472 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ11 PCI */
473 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
474 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
475 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
476 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
480 int __init acpi_irq_penalty_init(void)
482 struct acpi_pci_link *link;
486 * Update penalties to facilitate IRQ balancing.
488 list_for_each_entry(link, &acpi_link_list, list) {
491 * reflect the possible and active irqs in the penalty table --
492 * useful for breaking ties.
494 if (link->irq.possible_count) {
496 PIRQ_PENALTY_PCI_POSSIBLE /
497 link->irq.possible_count;
499 for (i = 0; i < link->irq.possible_count; i++) {
500 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
501 acpi_irq_penalty[link->irq.
506 } else if (link->irq.active) {
507 acpi_irq_penalty[link->irq.active] +=
508 PIRQ_PENALTY_PCI_POSSIBLE;
511 /* Add a penalty for the SCI */
512 acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
516 static int acpi_irq_balance = -1; /* 0: static, 1: balance */
518 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
523 if (link->irq.initialized) {
524 if (link->refcnt == 0)
525 /* This means the link is disabled but initialized */
526 acpi_pci_link_set(link, link->irq.active);
531 * search for active IRQ in list of possible IRQs.
533 for (i = 0; i < link->irq.possible_count; ++i) {
534 if (link->irq.active == link->irq.possible[i])
538 * forget active IRQ that is not in possible list
540 if (i == link->irq.possible_count) {
542 printk(KERN_WARNING PREFIX "_CRS %d not found"
543 " in _PRS\n", link->irq.active);
544 link->irq.active = 0;
548 * if active found, use it; else pick entry from end of possible list.
550 if (link->irq.active)
551 irq = link->irq.active;
553 irq = link->irq.possible[link->irq.possible_count - 1];
555 if (acpi_irq_balance || !link->irq.active) {
557 * Select the best IRQ. This is done in reverse to promote
558 * the use of IRQs 9, 10, 11, and >15.
560 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
561 if (acpi_irq_penalty[irq] >
562 acpi_irq_penalty[link->irq.possible[i]])
563 irq = link->irq.possible[i];
567 /* Attempt to enable the link device at this IRQ. */
568 if (acpi_pci_link_set(link, irq)) {
569 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
570 "Try pci=noacpi or acpi=off\n",
571 acpi_device_name(link->device),
572 acpi_device_bid(link->device));
575 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
576 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
577 acpi_device_name(link->device),
578 acpi_device_bid(link->device), link->irq.active);
581 link->irq.initialized = 1;
586 * acpi_pci_link_allocate_irq
587 * success: return IRQ >= 0
590 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
591 int *polarity, char **name)
594 struct acpi_device *device;
595 struct acpi_pci_link *link;
597 result = acpi_bus_get_device(handle, &device);
599 printk(KERN_ERR PREFIX "Invalid link device\n");
603 link = acpi_driver_data(device);
605 printk(KERN_ERR PREFIX "Invalid link context\n");
609 /* TBD: Support multiple index (IRQ) entries per Link Device */
611 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
615 mutex_lock(&acpi_link_lock);
616 if (acpi_pci_link_allocate(link)) {
617 mutex_unlock(&acpi_link_lock);
621 if (!link->irq.active) {
622 mutex_unlock(&acpi_link_lock);
623 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
627 mutex_unlock(&acpi_link_lock);
630 *triggering = link->irq.triggering;
632 *polarity = link->irq.polarity;
634 *name = acpi_device_bid(link->device);
635 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
636 "Link %s is referenced\n",
637 acpi_device_bid(link->device)));
638 return (link->irq.active);
642 * We don't change link's irq information here. After it is reenabled, we
643 * continue use the info
645 int acpi_pci_link_free_irq(acpi_handle handle)
647 struct acpi_device *device;
648 struct acpi_pci_link *link;
651 result = acpi_bus_get_device(handle, &device);
653 printk(KERN_ERR PREFIX "Invalid link device\n");
657 link = acpi_driver_data(device);
659 printk(KERN_ERR PREFIX "Invalid link context\n");
663 mutex_lock(&acpi_link_lock);
664 if (!link->irq.initialized) {
665 mutex_unlock(&acpi_link_lock);
666 printk(KERN_ERR PREFIX "Link isn't initialized\n");
671 * The Link reference count allows us to _DISable an unused link
672 * and suspend time, and set it again on resume.
673 * However, 2.6.12 still has irq_router.resume
674 * which blindly restores the link state.
675 * So we disable the reference count method
676 * to prevent duplicate acpi_pci_link_set()
677 * which would harm some systems
681 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
682 "Link %s is dereferenced\n",
683 acpi_device_bid(link->device)));
685 if (link->refcnt == 0)
686 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
688 mutex_unlock(&acpi_link_lock);
689 return (link->irq.active);
692 /* --------------------------------------------------------------------------
694 -------------------------------------------------------------------------- */
696 static int acpi_pci_link_add(struct acpi_device *device)
699 struct acpi_pci_link *link;
703 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
707 link->device = device;
708 strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
709 strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
710 device->driver_data = link;
712 mutex_lock(&acpi_link_lock);
713 result = acpi_pci_link_get_possible(link);
717 /* query and set link->irq.active */
718 acpi_pci_link_get_current(link);
720 printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
721 acpi_device_bid(device));
722 for (i = 0; i < link->irq.possible_count; i++) {
723 if (link->irq.active == link->irq.possible[i]) {
724 printk(" *%d", link->irq.possible[i]);
727 printk(" %d", link->irq.possible[i]);
733 printk(" *%d", link->irq.active);
735 if (!link->device->status.enabled)
736 printk(", disabled.");
740 list_add_tail(&link->list, &acpi_link_list);
743 /* disable all links -- to be activated on use */
744 acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
745 mutex_unlock(&acpi_link_lock);
753 static int acpi_pci_link_resume(struct acpi_pci_link *link)
755 if (link->refcnt && link->irq.active && link->irq.initialized)
756 return (acpi_pci_link_set(link, link->irq.active));
761 static int irqrouter_resume(struct sys_device *dev)
763 struct acpi_pci_link *link;
765 list_for_each_entry(link, &acpi_link_list, list) {
766 acpi_pci_link_resume(link);
771 static int acpi_pci_link_remove(struct acpi_device *device, int type)
773 struct acpi_pci_link *link;
775 link = acpi_driver_data(device);
777 mutex_lock(&acpi_link_lock);
778 list_del(&link->list);
779 mutex_unlock(&acpi_link_lock);
786 * modify acpi_irq_penalty[] from cmdline
788 static int __init acpi_irq_penalty_update(char *str, int used)
792 for (i = 0; i < 16; i++) {
796 retval = get_option(&str, &irq);
799 break; /* no number found */
804 if (irq >= ARRAY_SIZE(acpi_irq_penalty))
808 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
810 acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
812 if (retval != 2) /* no next number */
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.
825 void acpi_penalize_isa_irq(int irq, int active)
827 if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
829 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
831 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
836 * Over-ride default table to reserve additional IRQs for use by ISA
837 * e.g. acpi_irq_isa=5
838 * Useful for telling ACPI how not to interfere with your ISA sound card.
840 static int __init acpi_irq_isa(char *str)
842 return acpi_irq_penalty_update(str, 1);
845 __setup("acpi_irq_isa=", acpi_irq_isa);
848 * Over-ride default table to free additional IRQs for use by PCI
849 * e.g. acpi_irq_pci=7,15
850 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
852 static int __init acpi_irq_pci(char *str)
854 return acpi_irq_penalty_update(str, 0);
857 __setup("acpi_irq_pci=", acpi_irq_pci);
859 static int __init acpi_irq_nobalance_set(char *str)
861 acpi_irq_balance = 0;
865 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
867 static int __init acpi_irq_balance_set(char *str)
869 acpi_irq_balance = 1;
873 __setup("acpi_irq_balance", acpi_irq_balance_set);
875 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
876 static struct sysdev_class irqrouter_sysdev_class = {
878 .resume = irqrouter_resume,
881 static struct sys_device device_irqrouter = {
883 .cls = &irqrouter_sysdev_class,
886 static int __init irqrouter_init_sysfs(void)
890 if (acpi_disabled || acpi_noirq)
893 error = sysdev_class_register(&irqrouter_sysdev_class);
895 error = sysdev_register(&device_irqrouter);
900 device_initcall(irqrouter_init_sysfs);
902 static int __init acpi_pci_link_init(void)
907 if (acpi_irq_balance == -1) {
908 /* no command line switch: enable balancing in IOAPIC mode */
909 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
910 acpi_irq_balance = 1;
912 acpi_irq_balance = 0;
915 if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
921 subsys_initcall(acpi_pci_link_init);