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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
3 *
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 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
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.
14 *
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.
19 *
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.
23 *
24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25 */
26
27#include <linux/config.h>
28
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>
35#include <linux/pm.h>
36#include <linux/pci.h>
37#include <linux/acpi.h>
38#include <acpi/acpi_bus.h>
39#include <acpi/acpi_drivers.h>
40
41
42#define _COMPONENT ACPI_PCI_COMPONENT
43ACPI_MODULE_NAME ("pci_irq")
44
45static struct acpi_prt_list acpi_prt;
46static DEFINE_SPINLOCK(acpi_prt_lock);
47
48/* --------------------------------------------------------------------------
49 PCI IRQ Routing Table (PRT) Support
50 -------------------------------------------------------------------------- */
51
52static struct acpi_prt_entry *
53acpi_pci_irq_find_prt_entry (
54 int segment,
55 int bus,
56 int device,
57 int pin)
58{
59 struct list_head *node = NULL;
60 struct acpi_prt_entry *entry = NULL;
61
62 ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry");
63
64 if (!acpi_prt.count)
65 return_PTR(NULL);
66
67 /*
68 * Parse through all PRT entries looking for a match on the specified
69 * PCI device's segment, bus, device, and pin (don't care about func).
70 *
71 */
72 spin_lock(&acpi_prt_lock);
73 list_for_each(node, &acpi_prt.entries) {
74 entry = list_entry(node, struct acpi_prt_entry, node);
75 if ((segment == entry->id.segment)
76 && (bus == entry->id.bus)
77 && (device == entry->id.device)
78 && (pin == entry->pin)) {
79 spin_unlock(&acpi_prt_lock);
80 return_PTR(entry);
81 }
82 }
83
84 spin_unlock(&acpi_prt_lock);
85 return_PTR(NULL);
86}
87
88
89static int
90acpi_pci_irq_add_entry (
91 acpi_handle handle,
92 int segment,
93 int bus,
94 struct acpi_pci_routing_table *prt)
95{
96 struct acpi_prt_entry *entry = NULL;
97
98 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry");
99
100 if (!prt)
101 return_VALUE(-EINVAL);
102
103 entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
104 if (!entry)
105 return_VALUE(-ENOMEM);
106 memset(entry, 0, sizeof(struct acpi_prt_entry));
107
108 entry->id.segment = segment;
109 entry->id.bus = bus;
110 entry->id.device = (prt->address >> 16) & 0xFFFF;
111 entry->id.function = prt->address & 0xFFFF;
112 entry->pin = prt->pin;
113
114 /*
115 * Type 1: Dynamic
116 * ---------------
117 * The 'source' field specifies the PCI interrupt link device used to
118 * configure the IRQ assigned to this slot|dev|pin. The 'source_index'
119 * indicates which resource descriptor in the resource template (of
120 * the link device) this interrupt is allocated from.
121 *
122 * NOTE: Don't query the Link Device for IRQ information at this time
123 * because Link Device enumeration may not have occurred yet
124 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI
125 * namespace).
126 */
127 if (prt->source[0]) {
128 acpi_get_handle(handle, prt->source, &entry->link.handle);
129 entry->link.index = prt->source_index;
130 }
131 /*
132 * Type 2: Static
133 * --------------
134 * The 'source' field is NULL, and the 'source_index' field specifies
135 * the IRQ value, which is hardwired to specific interrupt inputs on
136 * the interrupt controller.
137 */
138 else
139 entry->link.index = prt->source_index;
140
141 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
142 " %02X:%02X:%02X[%c] -> %s[%d]\n",
143 entry->id.segment, entry->id.bus, entry->id.device,
144 ('A' + entry->pin), prt->source, entry->link.index));
145
146 spin_lock(&acpi_prt_lock);
147 list_add_tail(&entry->node, &acpi_prt.entries);
148 acpi_prt.count++;
149 spin_unlock(&acpi_prt_lock);
150
151 return_VALUE(0);
152}
153
154
155static void
156acpi_pci_irq_del_entry (
157 int segment,
158 int bus,
159 struct acpi_prt_entry *entry)
160{
161 if (segment == entry->id.segment && bus == entry->id.bus){
162 acpi_prt.count--;
163 list_del(&entry->node);
164 kfree(entry);
165 }
166}
167
168
169int
170acpi_pci_irq_add_prt (
171 acpi_handle handle,
172 int segment,
173 int bus)
174{
175 acpi_status status = AE_OK;
176 char *pathname = NULL;
177 struct acpi_buffer buffer = {0, NULL};
178 struct acpi_pci_routing_table *prt = NULL;
179 struct acpi_pci_routing_table *entry = NULL;
180 static int first_time = 1;
181
182 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt");
183
184 pathname = (char *) kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
185 if(!pathname)
186 return_VALUE(-ENOMEM);
187 memset(pathname, 0, ACPI_PATHNAME_MAX);
188
189 if (first_time) {
190 acpi_prt.count = 0;
191 INIT_LIST_HEAD(&acpi_prt.entries);
192 first_time = 0;
193 }
194
195 /*
196 * NOTE: We're given a 'handle' to the _PRT object's parent device
197 * (either a PCI root bridge or PCI-PCI bridge).
198 */
199
200 buffer.length = ACPI_PATHNAME_MAX;
201 buffer.pointer = pathname;
202 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
203
204 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
205 pathname);
206
207 /*
208 * Evaluate this _PRT and add its entries to our global list (acpi_prt).
209 */
210
211 buffer.length = 0;
212 buffer.pointer = NULL;
213 kfree(pathname);
214 status = acpi_get_irq_routing_table(handle, &buffer);
215 if (status != AE_BUFFER_OVERFLOW) {
216 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
217 acpi_format_exception(status)));
218 return_VALUE(-ENODEV);
219 }
220
221 prt = kmalloc(buffer.length, GFP_KERNEL);
222 if (!prt){
223 return_VALUE(-ENOMEM);
224 }
225 memset(prt, 0, buffer.length);
226 buffer.pointer = prt;
227
228 status = acpi_get_irq_routing_table(handle, &buffer);
229 if (ACPI_FAILURE(status)) {
230 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
231 acpi_format_exception(status)));
232 kfree(buffer.pointer);
233 return_VALUE(-ENODEV);
234 }
235
236 entry = prt;
237
238 while (entry && (entry->length > 0)) {
239 acpi_pci_irq_add_entry(handle, segment, bus, entry);
240 entry = (struct acpi_pci_routing_table *)
241 ((unsigned long) entry + entry->length);
242 }
243
244 kfree(prt);
245
246 return_VALUE(0);
247}
248
249void
250acpi_pci_irq_del_prt (int segment, int bus)
251{
252 struct list_head *node = NULL, *n = NULL;
253 struct acpi_prt_entry *entry = NULL;
254
255 if (!acpi_prt.count) {
256 return;
257 }
258
259 printk(KERN_DEBUG "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n",
260 segment, bus);
261 spin_lock(&acpi_prt_lock);
262 list_for_each_safe(node, n, &acpi_prt.entries) {
263 entry = list_entry(node, struct acpi_prt_entry, node);
264
265 acpi_pci_irq_del_entry(segment, bus, entry);
266 }
267 spin_unlock(&acpi_prt_lock);
268}
269/* --------------------------------------------------------------------------
270 PCI Interrupt Routing Support
271 -------------------------------------------------------------------------- */
272
273/*
274 * acpi_pci_irq_lookup
275 * success: return IRQ >= 0
276 * failure: return -1
277 */
278static int
279acpi_pci_irq_lookup (
280 struct pci_bus *bus,
281 int device,
282 int pin,
283 int *edge_level,
284 int *active_high_low,
285 char **link)
286{
287 struct acpi_prt_entry *entry = NULL;
288 int segment = pci_domain_nr(bus);
289 int bus_nr = bus->number;
290 int irq;
291
292 ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");
293
294 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
295 "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
296 segment, bus_nr, device, ('A' + pin)));
297
298 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
299 if (!entry) {
300 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
301 return_VALUE(-1);
302 }
303
304 if (entry->link.handle) {
305 irq = acpi_pci_link_get_irq(entry->link.handle,
306 entry->link.index, edge_level, active_high_low, link);
307 if (irq < 0) {
308 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n"));
309 return_VALUE(-1);
310 }
311 } else {
312 irq = entry->link.index;
313 *edge_level = ACPI_LEVEL_SENSITIVE;
314 *active_high_low = ACPI_ACTIVE_LOW;
315 }
316
317 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
318
319 return_VALUE(irq);
320}
321
322/*
323 * acpi_pci_irq_derive
324 * success: return IRQ >= 0
325 * failure: return < 0
326 */
327static int
328acpi_pci_irq_derive (
329 struct pci_dev *dev,
330 int pin,
331 int *edge_level,
332 int *active_high_low,
333 char **link)
334{
335 struct pci_dev *bridge = dev;
336 int irq = -1;
337 u8 bridge_pin = 0;
338
339 ACPI_FUNCTION_TRACE("acpi_pci_irq_derive");
340
341 if (!dev)
342 return_VALUE(-EINVAL);
343
344 /*
345 * Attempt to derive an IRQ for this device from a parent bridge's
346 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
347 */
348 while (irq < 0 && bridge->bus->self) {
349 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
350 bridge = bridge->bus->self;
351
352 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
353 /* PC card has the same IRQ as its cardbridge */
354 pci_read_config_byte(bridge, PCI_INTERRUPT_PIN, &bridge_pin);
355 if (!bridge_pin) {
356 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
357 "No interrupt pin configured for device %s\n", pci_name(bridge)));
358 return_VALUE(-1);
359 }
360 /* Pin is from 0 to 3 */
361 bridge_pin --;
362 pin = bridge_pin;
363 }
364
365 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
366 pin, edge_level, active_high_low, link);
367 }
368
369 if (irq < 0) {
370 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Unable to derive IRQ for device %s\n", pci_name(dev)));
371 return_VALUE(-1);
372 }
373
374 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
375 irq, pci_name(dev), pci_name(bridge)));
376
377 return_VALUE(irq);
378}
379
380/*
381 * acpi_pci_irq_enable
382 * success: return 0
383 * failure: return < 0
384 */
385
386int
387acpi_pci_irq_enable (
388 struct pci_dev *dev)
389{
390 int irq = 0;
391 u8 pin = 0;
392 int edge_level = ACPI_LEVEL_SENSITIVE;
393 int active_high_low = ACPI_ACTIVE_LOW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 char *link = NULL;
395
396 ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
397
398 if (!dev)
399 return_VALUE(-EINVAL);
400
401 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
402 if (!pin) {
403 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", pci_name(dev)));
404 return_VALUE(0);
405 }
406 pin--;
407
408 if (!dev->bus) {
409 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n"));
410 return_VALUE(-ENODEV);
411 }
412
413 /*
414 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT
415 * values override any BIOS-assigned IRQs set during boot.
416 */
417 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
418 &edge_level, &active_high_low, &link);
419
420 /*
421 * If no PRT entry was found, we'll try to derive an IRQ from the
422 * device's parent bridge.
423 */
424 if (irq < 0)
425 irq = acpi_pci_irq_derive(dev, pin, &edge_level,
426 &active_high_low, &link);
427
428 /*
429 * No IRQ known to the ACPI subsystem - maybe the BIOS /
430 * driver reported one, then use it. Exit in any case.
431 */
432 if (irq < 0) {
433 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
434 pci_name(dev), ('A' + pin));
435 /* Interrupt Line values above 0xF are forbidden */
Linus Torvalds44f8e1a2005-07-02 10:35:33 -0700436 if (dev->irq > 0 && (dev->irq <= 0xF)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 printk(" - using IRQ %d\n", dev->irq);
Linus Torvalds7be426c2005-06-25 10:01:36 -0700438 acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_LOW);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 return_VALUE(0);
440 }
441 else {
442 printk("\n");
443 return_VALUE(0);
444 }
445 }
446
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 dev->irq = acpi_register_gsi(irq, edge_level, active_high_low);
448
449 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
450 pci_name(dev), 'A' + pin);
451
452 if (link)
453 printk("Link [%s] -> ", link);
454
455 printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
456 (edge_level == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
457 (active_high_low == ACPI_ACTIVE_LOW) ? "low" : "high",
458 dev->irq);
459
460 return_VALUE(0);
461}
462EXPORT_SYMBOL(acpi_pci_irq_enable);
463
464
465#ifdef CONFIG_ACPI_DEALLOCATE_IRQ
466void
467acpi_pci_irq_disable (
468 struct pci_dev *dev)
469{
470 int gsi = 0;
471 u8 pin = 0;
472 int edge_level = ACPI_LEVEL_SENSITIVE;
473 int active_high_low = ACPI_ACTIVE_LOW;
474
475 ACPI_FUNCTION_TRACE("acpi_pci_irq_disable");
476
477 if (!dev)
478 return_VOID;
479
480 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
481 if (!pin)
482 return_VOID;
483 pin--;
484
485 if (!dev->bus)
486 return_VOID;
487
488 /*
489 * First we check the PCI IRQ routing table (PRT) for an IRQ.
490 */
491 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
492 &edge_level, &active_high_low, NULL);
493 /*
494 * If no PRT entry was found, we'll try to derive an IRQ from the
495 * device's parent bridge.
496 */
497 if (gsi < 0)
498 gsi = acpi_pci_irq_derive(dev, pin,
499 &edge_level, &active_high_low, NULL);
500 if (gsi < 0)
501 return_VOID;
502
503 /*
504 * TBD: It might be worth clearing dev->irq by magic constant
505 * (e.g. PCI_UNDEFINED_IRQ).
506 */
507
508 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
509 pci_name(dev));
510
511 acpi_unregister_gsi(gsi);
512
513 return_VOID;
514}
515#endif /* CONFIG_ACPI_DEALLOCATE_IRQ */