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>
7 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or (at
14 * your option) any later version.
16 * This program is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
21 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 * 1. Support more than one IRQ resource entry per link device (index).
25 * 2. Implement start/stop mechanism and use ACPI Bus Driver facilities
26 * for IRQ management (e.g. start()->_SRS).
29 #include <linux/syscore_ops.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/init.h>
33 #include <linux/types.h>
34 #include <linux/spinlock.h>
36 #include <linux/pci.h>
37 #include <linux/mutex.h>
38 #include <linux/slab.h>
39 #include <linux/acpi.h>
43 #define _COMPONENT ACPI_PCI_COMPONENT
44 ACPI_MODULE_NAME("pci_link");
45 #define ACPI_PCI_LINK_CLASS "pci_irq_routing"
46 #define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
47 #define ACPI_PCI_LINK_FILE_INFO "info"
48 #define ACPI_PCI_LINK_FILE_STATUS "state"
49 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
51 static int acpi_pci_link_add(struct acpi_device *device,
52 const struct acpi_device_id *not_used);
53 static void acpi_pci_link_remove(struct acpi_device *device);
55 static const struct acpi_device_id link_device_ids[] = {
60 static struct acpi_scan_handler pci_link_handler = {
61 .ids = link_device_ids,
62 .attach = acpi_pci_link_add,
63 .detach = acpi_pci_link_remove,
67 * If a link is initialized, we never change its active and initialized
68 * later even the link is disable. Instead, we just repick the active irq
70 struct acpi_pci_link_irq {
71 u32 active; /* Current IRQ */
72 u8 triggering; /* All IRQs */
73 u8 polarity; /* All IRQs */
76 u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
81 struct acpi_pci_link {
82 struct list_head list;
83 struct acpi_device *device;
84 struct acpi_pci_link_irq irq;
88 static LIST_HEAD(acpi_link_list);
89 static DEFINE_MUTEX(acpi_link_lock);
91 /* --------------------------------------------------------------------------
92 PCI Link Device Management
93 -------------------------------------------------------------------------- */
96 * set context (link) possible list from resource list
98 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
101 struct acpi_pci_link *link = context;
104 switch (resource->type) {
105 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
106 case ACPI_RESOURCE_TYPE_END_TAG:
108 case ACPI_RESOURCE_TYPE_IRQ:
110 struct acpi_resource_irq *p = &resource->data.irq;
111 if (!p || !p->interrupt_count) {
112 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
113 "Blank _PRS IRQ resource\n"));
117 (i < p->interrupt_count
118 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
119 if (!p->interrupts[i]) {
120 printk(KERN_WARNING PREFIX
121 "Invalid _PRS IRQ %d\n",
125 link->irq.possible[i] = p->interrupts[i];
126 link->irq.possible_count++;
128 link->irq.triggering = p->triggering;
129 link->irq.polarity = p->polarity;
130 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
133 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
135 struct acpi_resource_extended_irq *p =
136 &resource->data.extended_irq;
137 if (!p || !p->interrupt_count) {
138 printk(KERN_WARNING PREFIX
139 "Blank _PRS EXT IRQ resource\n");
143 (i < p->interrupt_count
144 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
145 if (!p->interrupts[i]) {
146 printk(KERN_WARNING PREFIX
147 "Invalid _PRS IRQ %d\n",
151 link->irq.possible[i] = p->interrupts[i];
152 link->irq.possible_count++;
154 link->irq.triggering = p->triggering;
155 link->irq.polarity = p->polarity;
156 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
160 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
165 return AE_CTRL_TERMINATE;
168 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
172 status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
173 acpi_pci_link_check_possible, link);
174 if (ACPI_FAILURE(status)) {
175 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
179 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
180 "Found %d possible IRQs\n",
181 link->irq.possible_count));
186 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
191 switch (resource->type) {
192 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
193 case ACPI_RESOURCE_TYPE_END_TAG:
195 case ACPI_RESOURCE_TYPE_IRQ:
197 struct acpi_resource_irq *p = &resource->data.irq;
198 if (!p || !p->interrupt_count) {
200 * IRQ descriptors may have no IRQ# bits set,
201 * particularly those those w/ _STA disabled
203 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
204 "Blank _CRS IRQ resource\n"));
207 *irq = p->interrupts[0];
210 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
212 struct acpi_resource_extended_irq *p =
213 &resource->data.extended_irq;
214 if (!p || !p->interrupt_count) {
216 * extended IRQ descriptors must
217 * return at least 1 IRQ
219 printk(KERN_WARNING PREFIX
220 "Blank _CRS EXT IRQ resource\n");
223 *irq = p->interrupts[0];
228 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
233 return AE_CTRL_TERMINATE;
237 * Run _CRS and set link->irq.active
243 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
249 link->irq.active = 0;
251 /* in practice, status disabled is meaningless, ignore it */
253 /* Query _STA, set link->device->status */
254 result = acpi_bus_get_status(link->device);
256 printk(KERN_ERR PREFIX "Unable to read status\n");
260 if (!link->device->status.enabled) {
261 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
267 * Query and parse _CRS to get the current IRQ assignment.
270 status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
271 acpi_pci_link_check_current, &irq);
272 if (ACPI_FAILURE(status)) {
273 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
278 if (acpi_strict && !irq) {
279 printk(KERN_ERR PREFIX "_CRS returned 0\n");
283 link->irq.active = irq;
285 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
291 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
296 struct acpi_resource res;
297 struct acpi_resource end;
299 struct acpi_buffer buffer = { 0, NULL };
304 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
308 buffer.length = sizeof(*resource) + 1;
309 buffer.pointer = resource;
311 switch (link->irq.resource_type) {
312 case ACPI_RESOURCE_TYPE_IRQ:
313 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
314 resource->res.length = sizeof(struct acpi_resource);
315 resource->res.data.irq.triggering = link->irq.triggering;
316 resource->res.data.irq.polarity =
318 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
319 resource->res.data.irq.sharable =
322 resource->res.data.irq.sharable = ACPI_SHARED;
323 resource->res.data.irq.interrupt_count = 1;
324 resource->res.data.irq.interrupts[0] = irq;
327 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
328 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
329 resource->res.length = sizeof(struct acpi_resource);
330 resource->res.data.extended_irq.producer_consumer =
332 resource->res.data.extended_irq.triggering =
333 link->irq.triggering;
334 resource->res.data.extended_irq.polarity =
336 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
337 resource->res.data.irq.sharable =
340 resource->res.data.irq.sharable = ACPI_SHARED;
341 resource->res.data.extended_irq.interrupt_count = 1;
342 resource->res.data.extended_irq.interrupts[0] = irq;
343 /* ignore resource_source, it's optional */
346 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
351 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
352 resource->end.length = sizeof(struct acpi_resource);
354 /* Attempt to set the resource */
355 status = acpi_set_current_resources(link->device->handle, &buffer);
357 /* check for total failure */
358 if (ACPI_FAILURE(status)) {
359 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
364 /* Query _STA, set device->status */
365 result = acpi_bus_get_status(link->device);
367 printk(KERN_ERR PREFIX "Unable to read status\n");
370 if (!link->device->status.enabled) {
371 printk(KERN_WARNING PREFIX
372 "%s [%s] disabled and referenced, BIOS bug\n",
373 acpi_device_name(link->device),
374 acpi_device_bid(link->device));
377 /* Query _CRS, set link->irq.active */
378 result = acpi_pci_link_get_current(link);
384 * Is current setting not what we set?
385 * set link->irq.active
387 if (link->irq.active != irq) {
389 * policy: when _CRS doesn't return what we just _SRS
390 * assume _SRS worked and override _CRS value.
392 printk(KERN_WARNING PREFIX
393 "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
394 acpi_device_name(link->device),
395 acpi_device_bid(link->device), link->irq.active, irq);
396 link->irq.active = irq;
399 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
406 /* --------------------------------------------------------------------------
407 PCI Link IRQ Management
408 -------------------------------------------------------------------------- */
411 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
412 * Link Devices to move the PIRQs around to minimize sharing.
414 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
415 * that the BIOS has already set to active. This is necessary because
416 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
417 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
418 * even if acpi_irq_nobalance is set.
420 * A tables of penalties avoids directing PCI interrupts to well known
421 * ISA IRQs. Boot params are available to over-ride the default table:
423 * List interrupts that are free for PCI use.
426 * List interrupts that should not be used for PCI:
429 * Note that PCI IRQ routers have a list of possible IRQs,
430 * which may not include the IRQs this table says are available.
432 * Since this heuristic can't tell the difference between a link
433 * that no device will attach to, vs. a link which may be shared
434 * by multiple active devices -- it is not optimal.
436 * If interrupt performance is that important, get an IO-APIC system
437 * with a pin dedicated to each device. Or for that matter, an MSI
441 #define ACPI_MAX_ISA_IRQ 16
443 #define PIRQ_PENALTY_PCI_AVAILABLE (0)
444 #define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
445 #define PIRQ_PENALTY_PCI_USING (16*16*16)
446 #define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
447 #define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
448 #define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
450 static int acpi_irq_isa_penalty[ACPI_MAX_ISA_IRQ] = {
451 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
452 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
453 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
454 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
455 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
456 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
457 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
458 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
459 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
460 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ9 PCI, often acpi */
461 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ10 PCI */
462 PIRQ_PENALTY_PCI_AVAILABLE, /* IRQ11 PCI */
463 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
464 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
465 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
466 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
469 struct irq_penalty_info {
472 struct list_head node;
475 static LIST_HEAD(acpi_irq_penalty_list);
477 static int acpi_irq_get_penalty(int irq)
479 struct irq_penalty_info *irq_info;
481 if (irq < ACPI_MAX_ISA_IRQ)
482 return acpi_irq_isa_penalty[irq];
484 list_for_each_entry(irq_info, &acpi_irq_penalty_list, node) {
485 if (irq_info->irq == irq)
486 return irq_info->penalty;
492 static int acpi_irq_set_penalty(int irq, int new_penalty)
494 struct irq_penalty_info *irq_info;
496 /* see if this is a ISA IRQ */
497 if (irq < ACPI_MAX_ISA_IRQ) {
498 acpi_irq_isa_penalty[irq] = new_penalty;
502 /* next, try to locate from the dynamic list */
503 list_for_each_entry(irq_info, &acpi_irq_penalty_list, node) {
504 if (irq_info->irq == irq) {
505 irq_info->penalty = new_penalty;
510 /* nope, let's allocate a slot for this IRQ */
511 irq_info = kzalloc(sizeof(*irq_info), GFP_KERNEL);
516 irq_info->penalty = new_penalty;
517 list_add_tail(&irq_info->node, &acpi_irq_penalty_list);
522 static void acpi_irq_add_penalty(int irq, int penalty)
524 int curpen = acpi_irq_get_penalty(irq);
526 acpi_irq_set_penalty(irq, curpen + penalty);
529 int __init acpi_irq_penalty_init(void)
531 struct acpi_pci_link *link;
535 * Update penalties to facilitate IRQ balancing.
537 list_for_each_entry(link, &acpi_link_list, list) {
540 * reflect the possible and active irqs in the penalty table --
541 * useful for breaking ties.
543 if (link->irq.possible_count) {
545 PIRQ_PENALTY_PCI_POSSIBLE /
546 link->irq.possible_count;
548 for (i = 0; i < link->irq.possible_count; i++) {
549 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ) {
550 int irqpos = link->irq.possible[i];
552 acpi_irq_add_penalty(irqpos, penalty);
556 } else if (link->irq.active) {
557 acpi_irq_add_penalty(link->irq.active,
558 PIRQ_PENALTY_PCI_POSSIBLE);
565 static int acpi_irq_balance = -1; /* 0: static, 1: balance */
567 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
572 if (link->irq.initialized) {
573 if (link->refcnt == 0)
574 /* This means the link is disabled but initialized */
575 acpi_pci_link_set(link, link->irq.active);
580 * search for active IRQ in list of possible IRQs.
582 for (i = 0; i < link->irq.possible_count; ++i) {
583 if (link->irq.active == link->irq.possible[i])
587 * forget active IRQ that is not in possible list
589 if (i == link->irq.possible_count) {
591 printk(KERN_WARNING PREFIX "_CRS %d not found"
592 " in _PRS\n", link->irq.active);
593 link->irq.active = 0;
597 * if active found, use it; else pick entry from end of possible list.
599 if (link->irq.active)
600 irq = link->irq.active;
602 irq = link->irq.possible[link->irq.possible_count - 1];
604 if (acpi_irq_balance || !link->irq.active) {
606 * Select the best IRQ. This is done in reverse to promote
607 * the use of IRQs 9, 10, 11, and >15.
609 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
610 if (acpi_irq_get_penalty(irq) >
611 acpi_irq_get_penalty(link->irq.possible[i]))
612 irq = link->irq.possible[i];
615 if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
616 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
617 "Try pci=noacpi or acpi=off\n",
618 acpi_device_name(link->device),
619 acpi_device_bid(link->device));
623 /* Attempt to enable the link device at this IRQ. */
624 if (acpi_pci_link_set(link, irq)) {
625 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
626 "Try pci=noacpi or acpi=off\n",
627 acpi_device_name(link->device),
628 acpi_device_bid(link->device));
631 acpi_irq_add_penalty(link->irq.active, PIRQ_PENALTY_PCI_USING);
633 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
634 acpi_device_name(link->device),
635 acpi_device_bid(link->device), link->irq.active);
638 link->irq.initialized = 1;
643 * acpi_pci_link_allocate_irq
644 * success: return IRQ >= 0
647 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
648 int *polarity, char **name)
651 struct acpi_device *device;
652 struct acpi_pci_link *link;
654 result = acpi_bus_get_device(handle, &device);
656 printk(KERN_ERR PREFIX "Invalid link device\n");
660 link = acpi_driver_data(device);
662 printk(KERN_ERR PREFIX "Invalid link context\n");
666 /* TBD: Support multiple index (IRQ) entries per Link Device */
668 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
672 mutex_lock(&acpi_link_lock);
673 if (acpi_pci_link_allocate(link)) {
674 mutex_unlock(&acpi_link_lock);
678 if (!link->irq.active) {
679 mutex_unlock(&acpi_link_lock);
680 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
684 mutex_unlock(&acpi_link_lock);
687 *triggering = link->irq.triggering;
689 *polarity = link->irq.polarity;
691 *name = acpi_device_bid(link->device);
692 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
693 "Link %s is referenced\n",
694 acpi_device_bid(link->device)));
695 return (link->irq.active);
699 * We don't change link's irq information here. After it is reenabled, we
700 * continue use the info
702 int acpi_pci_link_free_irq(acpi_handle handle)
704 struct acpi_device *device;
705 struct acpi_pci_link *link;
708 result = acpi_bus_get_device(handle, &device);
710 printk(KERN_ERR PREFIX "Invalid link device\n");
714 link = acpi_driver_data(device);
716 printk(KERN_ERR PREFIX "Invalid link context\n");
720 mutex_lock(&acpi_link_lock);
721 if (!link->irq.initialized) {
722 mutex_unlock(&acpi_link_lock);
723 printk(KERN_ERR PREFIX "Link isn't initialized\n");
728 * The Link reference count allows us to _DISable an unused link
729 * and suspend time, and set it again on resume.
730 * However, 2.6.12 still has irq_router.resume
731 * which blindly restores the link state.
732 * So we disable the reference count method
733 * to prevent duplicate acpi_pci_link_set()
734 * which would harm some systems
738 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
739 "Link %s is dereferenced\n",
740 acpi_device_bid(link->device)));
742 if (link->refcnt == 0)
743 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
745 mutex_unlock(&acpi_link_lock);
746 return (link->irq.active);
749 /* --------------------------------------------------------------------------
751 -------------------------------------------------------------------------- */
753 static int acpi_pci_link_add(struct acpi_device *device,
754 const struct acpi_device_id *not_used)
757 struct acpi_pci_link *link;
761 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
765 link->device = device;
766 strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
767 strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
768 device->driver_data = link;
770 mutex_lock(&acpi_link_lock);
771 result = acpi_pci_link_get_possible(link);
775 /* query and set link->irq.active */
776 acpi_pci_link_get_current(link);
778 printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
779 acpi_device_bid(device));
780 for (i = 0; i < link->irq.possible_count; i++) {
781 if (link->irq.active == link->irq.possible[i]) {
782 printk(KERN_CONT " *%d", link->irq.possible[i]);
785 printk(KERN_CONT " %d", link->irq.possible[i]);
788 printk(KERN_CONT ")");
791 printk(KERN_CONT " *%d", link->irq.active);
793 if (!link->device->status.enabled)
794 printk(KERN_CONT ", disabled.");
796 printk(KERN_CONT "\n");
798 list_add_tail(&link->list, &acpi_link_list);
801 /* disable all links -- to be activated on use */
802 acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
803 mutex_unlock(&acpi_link_lock);
808 return result < 0 ? result : 1;
811 static int acpi_pci_link_resume(struct acpi_pci_link *link)
813 if (link->refcnt && link->irq.active && link->irq.initialized)
814 return (acpi_pci_link_set(link, link->irq.active));
819 static void irqrouter_resume(void)
821 struct acpi_pci_link *link;
823 list_for_each_entry(link, &acpi_link_list, list) {
824 acpi_pci_link_resume(link);
828 static void acpi_pci_link_remove(struct acpi_device *device)
830 struct acpi_pci_link *link;
832 link = acpi_driver_data(device);
834 mutex_lock(&acpi_link_lock);
835 list_del(&link->list);
836 mutex_unlock(&acpi_link_lock);
842 * modify penalty from cmdline
844 static int __init acpi_irq_penalty_update(char *str, int used)
848 for (i = 0; i < 16; i++) {
852 retval = get_option(&str, &irq);
855 break; /* no number found */
861 acpi_irq_add_penalty(irq, PIRQ_PENALTY_ISA_USED);
863 acpi_irq_set_penalty(irq, PIRQ_PENALTY_PCI_AVAILABLE);
865 if (retval != 2) /* no next number */
872 * We'd like PNP to call this routine for the
873 * single ISA_USED value for each legacy device.
874 * But instead it calls us with each POSSIBLE setting.
875 * There is no ISA_POSSIBLE weight, so we simply use
876 * the (small) PCI_USING penalty.
878 void acpi_penalize_isa_irq(int irq, int active)
881 acpi_irq_add_penalty(irq, active ?
882 PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
885 bool acpi_isa_irq_available(int irq)
888 (acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
892 * Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict with
893 * PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be use for
896 void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
903 if (trigger != ACPI_MADT_TRIGGER_LEVEL ||
904 polarity != ACPI_MADT_POLARITY_ACTIVE_LOW)
905 penalty = PIRQ_PENALTY_ISA_ALWAYS;
907 penalty = PIRQ_PENALTY_PCI_USING;
909 acpi_irq_add_penalty(irq, penalty);
913 * Over-ride default table to reserve additional IRQs for use by ISA
914 * e.g. acpi_irq_isa=5
915 * Useful for telling ACPI how not to interfere with your ISA sound card.
917 static int __init acpi_irq_isa(char *str)
919 return acpi_irq_penalty_update(str, 1);
922 __setup("acpi_irq_isa=", acpi_irq_isa);
925 * Over-ride default table to free additional IRQs for use by PCI
926 * e.g. acpi_irq_pci=7,15
927 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
929 static int __init acpi_irq_pci(char *str)
931 return acpi_irq_penalty_update(str, 0);
934 __setup("acpi_irq_pci=", acpi_irq_pci);
936 static int __init acpi_irq_nobalance_set(char *str)
938 acpi_irq_balance = 0;
942 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
944 static int __init acpi_irq_balance_set(char *str)
946 acpi_irq_balance = 1;
950 __setup("acpi_irq_balance", acpi_irq_balance_set);
952 static struct syscore_ops irqrouter_syscore_ops = {
953 .resume = irqrouter_resume,
956 void __init acpi_pci_link_init(void)
961 if (acpi_irq_balance == -1) {
962 /* no command line switch: enable balancing in IOAPIC mode */
963 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
964 acpi_irq_balance = 1;
966 acpi_irq_balance = 0;
968 register_syscore_ops(&irqrouter_syscore_ops);
969 acpi_scan_add_handler(&pci_link_handler);