2 * pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
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 #include <linux/config.h>
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/types.h>
33 #include <linux/proc_fs.h>
34 #include <linux/spinlock.h>
36 #include <linux/pci.h>
37 #include <linux/acpi.h>
38 #include <acpi/acpi_bus.h>
39 #include <acpi/acpi_drivers.h>
41 #define _COMPONENT ACPI_PCI_COMPONENT
42 ACPI_MODULE_NAME("pci_irq")
44 static struct acpi_prt_list acpi_prt;
45 static DEFINE_SPINLOCK(acpi_prt_lock);
47 /* --------------------------------------------------------------------------
48 PCI IRQ Routing Table (PRT) Support
49 -------------------------------------------------------------------------- */
51 static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(int segment,
55 struct list_head *node = NULL;
56 struct acpi_prt_entry *entry = NULL;
63 * Parse through all PRT entries looking for a match on the specified
64 * PCI device's segment, bus, device, and pin (don't care about func).
67 spin_lock(&acpi_prt_lock);
68 list_for_each(node, &acpi_prt.entries) {
69 entry = list_entry(node, struct acpi_prt_entry, node);
70 if ((segment == entry->id.segment)
71 && (bus == entry->id.bus)
72 && (device == entry->id.device)
73 && (pin == entry->pin)) {
74 spin_unlock(&acpi_prt_lock);
79 spin_unlock(&acpi_prt_lock);
84 acpi_pci_irq_add_entry(acpi_handle handle,
85 int segment, int bus, struct acpi_pci_routing_table *prt)
87 struct acpi_prt_entry *entry = NULL;
93 entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
96 memset(entry, 0, sizeof(struct acpi_prt_entry));
98 entry->id.segment = segment;
100 entry->id.device = (prt->address >> 16) & 0xFFFF;
101 entry->id.function = prt->address & 0xFFFF;
102 entry->pin = prt->pin;
107 * The 'source' field specifies the PCI interrupt link device used to
108 * configure the IRQ assigned to this slot|dev|pin. The 'source_index'
109 * indicates which resource descriptor in the resource template (of
110 * the link device) this interrupt is allocated from.
112 * NOTE: Don't query the Link Device for IRQ information at this time
113 * because Link Device enumeration may not have occurred yet
114 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI
117 if (prt->source[0]) {
118 acpi_get_handle(handle, prt->source, &entry->link.handle);
119 entry->link.index = prt->source_index;
124 * The 'source' field is NULL, and the 'source_index' field specifies
125 * the IRQ value, which is hardwired to specific interrupt inputs on
126 * the interrupt controller.
129 entry->link.index = prt->source_index;
131 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
132 " %02X:%02X:%02X[%c] -> %s[%d]\n",
133 entry->id.segment, entry->id.bus,
134 entry->id.device, ('A' + entry->pin), prt->source,
137 spin_lock(&acpi_prt_lock);
138 list_add_tail(&entry->node, &acpi_prt.entries);
140 spin_unlock(&acpi_prt_lock);
146 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry)
148 if (segment == entry->id.segment && bus == entry->id.bus) {
150 list_del(&entry->node);
155 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
157 acpi_status status = AE_OK;
158 char *pathname = NULL;
159 struct acpi_buffer buffer = { 0, NULL };
160 struct acpi_pci_routing_table *prt = NULL;
161 struct acpi_pci_routing_table *entry = NULL;
162 static int first_time = 1;
165 pathname = (char *)kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
168 memset(pathname, 0, ACPI_PATHNAME_MAX);
172 INIT_LIST_HEAD(&acpi_prt.entries);
177 * NOTE: We're given a 'handle' to the _PRT object's parent device
178 * (either a PCI root bridge or PCI-PCI bridge).
181 buffer.length = ACPI_PATHNAME_MAX;
182 buffer.pointer = pathname;
183 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
185 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
189 * Evaluate this _PRT and add its entries to our global list (acpi_prt).
193 buffer.pointer = NULL;
195 status = acpi_get_irq_routing_table(handle, &buffer);
196 if (status != AE_BUFFER_OVERFLOW) {
197 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
198 acpi_format_exception(status)));
202 prt = kmalloc(buffer.length, GFP_KERNEL);
206 memset(prt, 0, buffer.length);
207 buffer.pointer = prt;
209 status = acpi_get_irq_routing_table(handle, &buffer);
210 if (ACPI_FAILURE(status)) {
211 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
212 acpi_format_exception(status)));
213 kfree(buffer.pointer);
219 while (entry && (entry->length > 0)) {
220 acpi_pci_irq_add_entry(handle, segment, bus, entry);
221 entry = (struct acpi_pci_routing_table *)
222 ((unsigned long)entry + entry->length);
230 void acpi_pci_irq_del_prt(int segment, int bus)
232 struct list_head *node = NULL, *n = NULL;
233 struct acpi_prt_entry *entry = NULL;
235 if (!acpi_prt.count) {
240 "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment,
242 spin_lock(&acpi_prt_lock);
243 list_for_each_safe(node, n, &acpi_prt.entries) {
244 entry = list_entry(node, struct acpi_prt_entry, node);
246 acpi_pci_irq_del_entry(segment, bus, entry);
248 spin_unlock(&acpi_prt_lock);
251 /* --------------------------------------------------------------------------
252 PCI Interrupt Routing Support
253 -------------------------------------------------------------------------- */
254 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **);
257 acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
258 int *triggering, int *polarity, char **link)
263 if (entry->link.handle) {
264 irq = acpi_pci_link_allocate_irq(entry->link.handle,
265 entry->link.index, triggering,
268 printk(KERN_WARNING PREFIX
269 "Invalid IRQ link routing entry\n");
273 irq = entry->link.index;
274 *triggering = ACPI_LEVEL_SENSITIVE;
275 *polarity = ACPI_ACTIVE_LOW;
278 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
283 acpi_pci_free_irq(struct acpi_prt_entry *entry,
284 int *triggering, int *polarity, char **link)
288 if (entry->link.handle) {
289 irq = acpi_pci_link_free_irq(entry->link.handle);
291 irq = entry->link.index;
297 * acpi_pci_irq_lookup
298 * success: return IRQ >= 0
302 acpi_pci_irq_lookup(struct pci_bus *bus,
306 int *polarity, char **link, irq_lookup_func func)
308 struct acpi_prt_entry *entry = NULL;
309 int segment = pci_domain_nr(bus);
310 int bus_nr = bus->number;
314 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
315 "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
316 segment, bus_nr, device, ('A' + pin)));
318 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
320 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
324 ret = func(entry, triggering, polarity, link);
329 * acpi_pci_irq_derive
330 * success: return IRQ >= 0
331 * failure: return < 0
334 acpi_pci_irq_derive(struct pci_dev *dev,
337 int *polarity, char **link, irq_lookup_func func)
339 struct pci_dev *bridge = dev;
348 * Attempt to derive an IRQ for this device from a parent bridge's
349 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
351 while (irq < 0 && bridge->bus->self) {
352 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
353 bridge = bridge->bus->self;
355 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
356 /* PC card has the same IRQ as its cardbridge */
357 bridge_pin = bridge->pin;
359 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
360 "No interrupt pin configured for device %s\n",
364 /* Pin is from 0 to 3 */
369 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
370 pin, triggering, polarity,
375 printk(KERN_WARNING PREFIX "Unable to derive IRQ for device %s\n",
380 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
381 irq, pci_name(dev), pci_name(bridge)));
387 * acpi_pci_irq_enable
389 * failure: return < 0
392 int acpi_pci_irq_enable(struct pci_dev *dev)
396 int triggering = ACPI_LEVEL_SENSITIVE;
397 int polarity = ACPI_ACTIVE_LOW;
407 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
408 "No interrupt pin configured for device %s\n",
415 printk(KERN_ERR PREFIX "Invalid (NULL) 'bus' field\n");
420 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT
421 * values override any BIOS-assigned IRQs set during boot.
423 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
424 &triggering, &polarity, &link,
425 acpi_pci_allocate_irq);
428 * If no PRT entry was found, we'll try to derive an IRQ from the
429 * device's parent bridge.
432 irq = acpi_pci_irq_derive(dev, pin, &triggering,
434 acpi_pci_allocate_irq);
437 * No IRQ known to the ACPI subsystem - maybe the BIOS /
438 * driver reported one, then use it. Exit in any case.
441 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
442 pci_name(dev), ('A' + pin));
443 /* Interrupt Line values above 0xF are forbidden */
444 if (dev->irq > 0 && (dev->irq <= 0xF)) {
445 printk(" - using IRQ %d\n", dev->irq);
446 acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
455 rc = acpi_register_gsi(irq, triggering, polarity);
457 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
458 "to register GSI\n", pci_name(dev), ('A' + pin));
463 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
464 pci_name(dev), 'A' + pin);
467 printk("Link [%s] -> ", link);
469 printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
470 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
471 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
476 EXPORT_SYMBOL(acpi_pci_irq_enable);
478 /* FIXME: implement x86/x86_64 version */
479 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
483 void acpi_pci_irq_disable(struct pci_dev *dev)
487 int triggering = ACPI_LEVEL_SENSITIVE;
488 int polarity = ACPI_ACTIVE_LOW;
491 if (!dev || !dev->bus)
500 * First we check the PCI IRQ routing table (PRT) for an IRQ.
502 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
503 &triggering, &polarity, NULL,
506 * If no PRT entry was found, we'll try to derive an IRQ from the
507 * device's parent bridge.
510 gsi = acpi_pci_irq_derive(dev, pin,
511 &triggering, &polarity, NULL,
517 * TBD: It might be worth clearing dev->irq by magic constant
518 * (e.g. PCI_UNDEFINED_IRQ).
521 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
524 acpi_unregister_gsi(gsi);