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 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/types.h>
32 #include <linux/proc_fs.h>
33 #include <linux/spinlock.h>
35 #include <linux/pci.h>
36 #include <linux/acpi.h>
37 #include <acpi/acpi_bus.h>
38 #include <acpi/acpi_drivers.h>
40 #define _COMPONENT ACPI_PCI_COMPONENT
41 ACPI_MODULE_NAME("pci_irq")
43 static struct acpi_prt_list acpi_prt;
44 static DEFINE_SPINLOCK(acpi_prt_lock);
46 /* --------------------------------------------------------------------------
47 PCI IRQ Routing Table (PRT) Support
48 -------------------------------------------------------------------------- */
50 static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(int segment,
54 struct list_head *node = NULL;
55 struct acpi_prt_entry *entry = NULL;
57 ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry");
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;
89 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry");
92 return_VALUE(-EINVAL);
94 entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
96 return_VALUE(-ENOMEM);
97 memset(entry, 0, sizeof(struct acpi_prt_entry));
99 entry->id.segment = segment;
101 entry->id.device = (prt->address >> 16) & 0xFFFF;
102 entry->id.function = prt->address & 0xFFFF;
103 entry->pin = prt->pin;
108 * The 'source' field specifies the PCI interrupt link device used to
109 * configure the IRQ assigned to this slot|dev|pin. The 'source_index'
110 * indicates which resource descriptor in the resource template (of
111 * the link device) this interrupt is allocated from.
113 * NOTE: Don't query the Link Device for IRQ information at this time
114 * because Link Device enumeration may not have occurred yet
115 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI
118 if (prt->source[0]) {
119 acpi_get_handle(handle, prt->source, &entry->link.handle);
120 entry->link.index = prt->source_index;
125 * The 'source' field is NULL, and the 'source_index' field specifies
126 * the IRQ value, which is hardwired to specific interrupt inputs on
127 * the interrupt controller.
130 entry->link.index = prt->source_index;
132 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
133 " %02X:%02X:%02X[%c] -> %s[%d]\n",
134 entry->id.segment, entry->id.bus,
135 entry->id.device, ('A' + entry->pin), prt->source,
138 spin_lock(&acpi_prt_lock);
139 list_add_tail(&entry->node, &acpi_prt.entries);
141 spin_unlock(&acpi_prt_lock);
147 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry)
149 if (segment == entry->id.segment && bus == entry->id.bus) {
151 list_del(&entry->node);
156 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
158 acpi_status status = AE_OK;
159 char *pathname = NULL;
160 struct acpi_buffer buffer = { 0, NULL };
161 struct acpi_pci_routing_table *prt = NULL;
162 struct acpi_pci_routing_table *entry = NULL;
163 static int first_time = 1;
165 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt");
167 pathname = (char *)kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
169 return_VALUE(-ENOMEM);
170 memset(pathname, 0, ACPI_PATHNAME_MAX);
174 INIT_LIST_HEAD(&acpi_prt.entries);
179 * NOTE: We're given a 'handle' to the _PRT object's parent device
180 * (either a PCI root bridge or PCI-PCI bridge).
183 buffer.length = ACPI_PATHNAME_MAX;
184 buffer.pointer = pathname;
185 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
187 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
191 * Evaluate this _PRT and add its entries to our global list (acpi_prt).
195 buffer.pointer = NULL;
197 status = acpi_get_irq_routing_table(handle, &buffer);
198 if (status != AE_BUFFER_OVERFLOW) {
199 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
200 acpi_format_exception(status)));
201 return_VALUE(-ENODEV);
204 prt = kmalloc(buffer.length, GFP_KERNEL);
206 return_VALUE(-ENOMEM);
208 memset(prt, 0, buffer.length);
209 buffer.pointer = prt;
211 status = acpi_get_irq_routing_table(handle, &buffer);
212 if (ACPI_FAILURE(status)) {
213 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
214 acpi_format_exception(status)));
215 kfree(buffer.pointer);
216 return_VALUE(-ENODEV);
221 while (entry && (entry->length > 0)) {
222 acpi_pci_irq_add_entry(handle, segment, bus, entry);
223 entry = (struct acpi_pci_routing_table *)
224 ((unsigned long)entry + entry->length);
232 void acpi_pci_irq_del_prt(int segment, int bus)
234 struct list_head *node = NULL, *n = NULL;
235 struct acpi_prt_entry *entry = NULL;
237 if (!acpi_prt.count) {
242 "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment,
244 spin_lock(&acpi_prt_lock);
245 list_for_each_safe(node, n, &acpi_prt.entries) {
246 entry = list_entry(node, struct acpi_prt_entry, node);
248 acpi_pci_irq_del_entry(segment, bus, entry);
250 spin_unlock(&acpi_prt_lock);
253 /* --------------------------------------------------------------------------
254 PCI Interrupt Routing Support
255 -------------------------------------------------------------------------- */
256 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **);
259 acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
260 int *triggering, int *polarity, char **link)
264 ACPI_FUNCTION_TRACE("acpi_pci_allocate_irq");
266 if (entry->link.handle) {
267 irq = acpi_pci_link_allocate_irq(entry->link.handle,
268 entry->link.index, triggering,
271 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
272 "Invalid IRQ link routing entry\n"));
276 irq = entry->link.index;
277 *triggering = ACPI_LEVEL_SENSITIVE;
278 *polarity = ACPI_ACTIVE_LOW;
281 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
286 acpi_pci_free_irq(struct acpi_prt_entry *entry,
287 int *triggering, int *polarity, char **link)
291 ACPI_FUNCTION_TRACE("acpi_pci_free_irq");
292 if (entry->link.handle) {
293 irq = acpi_pci_link_free_irq(entry->link.handle);
295 irq = entry->link.index;
301 * acpi_pci_irq_lookup
302 * success: return IRQ >= 0
306 acpi_pci_irq_lookup(struct pci_bus *bus,
310 int *polarity, char **link, irq_lookup_func func)
312 struct acpi_prt_entry *entry = NULL;
313 int segment = pci_domain_nr(bus);
314 int bus_nr = bus->number;
317 ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");
319 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
320 "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
321 segment, bus_nr, device, ('A' + pin)));
323 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
325 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
329 ret = func(entry, triggering, polarity, link);
334 * acpi_pci_irq_derive
335 * success: return IRQ >= 0
336 * failure: return < 0
339 acpi_pci_irq_derive(struct pci_dev *dev,
342 int *polarity, char **link, irq_lookup_func func)
344 struct pci_dev *bridge = dev;
348 ACPI_FUNCTION_TRACE("acpi_pci_irq_derive");
351 return_VALUE(-EINVAL);
354 * Attempt to derive an IRQ for this device from a parent bridge's
355 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
357 while (irq < 0 && bridge->bus->self) {
358 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
359 bridge = bridge->bus->self;
361 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
362 /* PC card has the same IRQ as its cardbridge */
363 bridge_pin = bridge->pin;
365 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
366 "No interrupt pin configured for device %s\n",
370 /* Pin is from 0 to 3 */
375 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
376 pin, triggering, polarity,
381 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
382 "Unable to derive IRQ for device %s\n",
387 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
388 irq, pci_name(dev), pci_name(bridge)));
394 * acpi_pci_irq_enable
396 * failure: return < 0
399 int acpi_pci_irq_enable(struct pci_dev *dev)
403 int triggering = ACPI_LEVEL_SENSITIVE;
404 int polarity = ACPI_ACTIVE_LOW;
408 ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
411 return_VALUE(-EINVAL);
415 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
416 "No interrupt pin configured for device %s\n",
423 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
424 "Invalid (NULL) 'bus' field\n"));
425 return_VALUE(-ENODEV);
429 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT
430 * values override any BIOS-assigned IRQs set during boot.
432 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
433 &triggering, &polarity, &link,
434 acpi_pci_allocate_irq);
437 * If no PRT entry was found, we'll try to derive an IRQ from the
438 * device's parent bridge.
441 irq = acpi_pci_irq_derive(dev, pin, &triggering,
443 acpi_pci_allocate_irq);
446 * No IRQ known to the ACPI subsystem - maybe the BIOS /
447 * driver reported one, then use it. Exit in any case.
450 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
451 pci_name(dev), ('A' + pin));
452 /* Interrupt Line values above 0xF are forbidden */
453 if (dev->irq > 0 && (dev->irq <= 0xF)) {
454 printk(" - using IRQ %d\n", dev->irq);
455 acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
464 rc = acpi_register_gsi(irq, triggering, polarity);
466 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
467 "to register GSI\n", pci_name(dev), ('A' + pin));
472 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
473 pci_name(dev), 'A' + pin);
476 printk("Link [%s] -> ", link);
478 printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
479 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
480 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
485 EXPORT_SYMBOL(acpi_pci_irq_enable);
487 /* FIXME: implement x86/x86_64 version */
488 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
492 void acpi_pci_irq_disable(struct pci_dev *dev)
496 int triggering = ACPI_LEVEL_SENSITIVE;
497 int polarity = ACPI_ACTIVE_LOW;
499 ACPI_FUNCTION_TRACE("acpi_pci_irq_disable");
501 if (!dev || !dev->bus)
510 * First we check the PCI IRQ routing table (PRT) for an IRQ.
512 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
513 &triggering, &polarity, NULL,
516 * If no PRT entry was found, we'll try to derive an IRQ from the
517 * device's parent bridge.
520 gsi = acpi_pci_irq_derive(dev, pin,
521 &triggering, &polarity, NULL,
527 * TBD: It might be worth clearing dev->irq by magic constant
528 * (e.g. PCI_UNDEFINED_IRQ).
531 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
534 acpi_unregister_gsi(gsi);