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[PATCH] notifiers: fix blocking_notifier_call_chain() scalability
[linux/fpc-iii.git] / drivers / acpi / pci_irq.c
blobfe7d007833ade1b03ba2660269bcd10d42440c54
1 /*
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
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>
34 #include <linux/pm.h>
35 #include <linux/pci.h>
36 #include <linux/acpi.h>
37 #include <acpi/acpi_bus.h>
38 #include <acpi/acpi_drivers.h>
39
40 #define _COMPONENT ACPI_PCI_COMPONENT
41 ACPI_MODULE_NAME("pci_irq")
42
43 static struct acpi_prt_list acpi_prt;
44 static DEFINE_SPINLOCK(acpi_prt_lock);
45
46 /* --------------------------------------------------------------------------
47 PCI IRQ Routing Table (PRT) Support
48 -------------------------------------------------------------------------- */
49
50 static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(int segment,
51 int bus,
52 int device, int pin)
53 {
54 struct list_head *node = NULL;
55 struct acpi_prt_entry *entry = NULL;
56
57
58 if (!acpi_prt.count)
59 return NULL;
60
61 /*
62 * Parse through all PRT entries looking for a match on the specified
63 * PCI device's segment, bus, device, and pin (don't care about func).
64 *
65 */
66 spin_lock(&acpi_prt_lock);
67 list_for_each(node, &acpi_prt.entries) {
68 entry = list_entry(node, struct acpi_prt_entry, node);
69 if ((segment == entry->id.segment)
70 && (bus == entry->id.bus)
71 && (device == entry->id.device)
72 && (pin == entry->pin)) {
73 spin_unlock(&acpi_prt_lock);
74 return entry;
75 }
76 }
77
78 spin_unlock(&acpi_prt_lock);
79 return NULL;
80 }
81
82 static int
83 acpi_pci_irq_add_entry(acpi_handle handle,
84 int segment, int bus, struct acpi_pci_routing_table *prt)
85 {
86 struct acpi_prt_entry *entry = NULL;
87
88
89 if (!prt)
90 return -EINVAL;
91
92 entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
93 if (!entry)
94 return -ENOMEM;
95
96 entry->id.segment = segment;
97 entry->id.bus = bus;
98 entry->id.device = (prt->address >> 16) & 0xFFFF;
99 entry->id.function = prt->address & 0xFFFF;
100 entry->pin = prt->pin;
101
102 /*
103 * Type 1: Dynamic
104 * ---------------
105 * The 'source' field specifies the PCI interrupt link device used to
106 * configure the IRQ assigned to this slot|dev|pin. The 'source_index'
107 * indicates which resource descriptor in the resource template (of
108 * the link device) this interrupt is allocated from.
109 *
110 * NOTE: Don't query the Link Device for IRQ information at this time
111 * because Link Device enumeration may not have occurred yet
112 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI
113 * namespace).
114 */
115 if (prt->source[0]) {
116 acpi_get_handle(handle, prt->source, &entry->link.handle);
117 entry->link.index = prt->source_index;
118 }
119 /*
120 * Type 2: Static
121 * --------------
122 * The 'source' field is NULL, and the 'source_index' field specifies
123 * the IRQ value, which is hardwired to specific interrupt inputs on
124 * the interrupt controller.
125 */
126 else
127 entry->link.index = prt->source_index;
128
129 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
130 " %02X:%02X:%02X[%c] -> %s[%d]\n",
131 entry->id.segment, entry->id.bus,
132 entry->id.device, ('A' + entry->pin), prt->source,
133 entry->link.index));
134
135 spin_lock(&acpi_prt_lock);
136 list_add_tail(&entry->node, &acpi_prt.entries);
137 acpi_prt.count++;
138 spin_unlock(&acpi_prt_lock);
139
140 return 0;
141 }
142
143 static void
144 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry)
145 {
146 if (segment == entry->id.segment && bus == entry->id.bus) {
147 acpi_prt.count--;
148 list_del(&entry->node);
149 kfree(entry);
150 }
151 }
152
153 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
154 {
155 acpi_status status = AE_OK;
156 char *pathname = NULL;
157 struct acpi_buffer buffer = { 0, NULL };
158 struct acpi_pci_routing_table *prt = NULL;
159 struct acpi_pci_routing_table *entry = NULL;
160 static int first_time = 1;
161
162
163 pathname = kzalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
164 if (!pathname)
165 return -ENOMEM;
166
167 if (first_time) {
168 acpi_prt.count = 0;
169 INIT_LIST_HEAD(&acpi_prt.entries);
170 first_time = 0;
171 }
172
173 /*
174 * NOTE: We're given a 'handle' to the _PRT object's parent device
175 * (either a PCI root bridge or PCI-PCI bridge).
176 */
177
178 buffer.length = ACPI_PATHNAME_MAX;
179 buffer.pointer = pathname;
180 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
181
182 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
183 pathname);
184
185 /*
186 * Evaluate this _PRT and add its entries to our global list (acpi_prt).
187 */
188
189 buffer.length = 0;
190 buffer.pointer = NULL;
191 kfree(pathname);
192 status = acpi_get_irq_routing_table(handle, &buffer);
193 if (status != AE_BUFFER_OVERFLOW) {
194 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
195 acpi_format_exception(status)));
196 return -ENODEV;
197 }
198
199 prt = kzalloc(buffer.length, GFP_KERNEL);
200 if (!prt) {
201 return -ENOMEM;
202 }
203 buffer.pointer = prt;
204
205 status = acpi_get_irq_routing_table(handle, &buffer);
206 if (ACPI_FAILURE(status)) {
207 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
208 acpi_format_exception(status)));
209 kfree(buffer.pointer);
210 return -ENODEV;
211 }
212
213 entry = prt;
214
215 while (entry && (entry->length > 0)) {
216 acpi_pci_irq_add_entry(handle, segment, bus, entry);
217 entry = (struct acpi_pci_routing_table *)
218 ((unsigned long)entry + entry->length);
219 }
220
221 kfree(prt);
222
223 return 0;
224 }
225
226 void acpi_pci_irq_del_prt(int segment, int bus)
227 {
228 struct list_head *node = NULL, *n = NULL;
229 struct acpi_prt_entry *entry = NULL;
230
231 if (!acpi_prt.count) {
232 return;
233 }
234
235 printk(KERN_DEBUG
236 "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment,
237 bus);
238 spin_lock(&acpi_prt_lock);
239 list_for_each_safe(node, n, &acpi_prt.entries) {
240 entry = list_entry(node, struct acpi_prt_entry, node);
241
242 acpi_pci_irq_del_entry(segment, bus, entry);
243 }
244 spin_unlock(&acpi_prt_lock);
245 }
246
247 /* --------------------------------------------------------------------------
248 PCI Interrupt Routing Support
249 -------------------------------------------------------------------------- */
250 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **);
251
252 static int
253 acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
254 int *triggering, int *polarity, char **link)
255 {
256 int irq;
257
258
259 if (entry->link.handle) {
260 irq = acpi_pci_link_allocate_irq(entry->link.handle,
261 entry->link.index, triggering,
262 polarity, link);
263 if (irq < 0) {
264 printk(KERN_WARNING PREFIX
265 "Invalid IRQ link routing entry\n");
266 return -1;
267 }
268 } else {
269 irq = entry->link.index;
270 *triggering = ACPI_LEVEL_SENSITIVE;
271 *polarity = ACPI_ACTIVE_LOW;
272 }
273
274 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
275 return irq;
276 }
277
278 static int
279 acpi_pci_free_irq(struct acpi_prt_entry *entry,
280 int *triggering, int *polarity, char **link)
281 {
282 int irq;
283
284 if (entry->link.handle) {
285 irq = acpi_pci_link_free_irq(entry->link.handle);
286 } else {
287 irq = entry->link.index;
288 }
289 return irq;
290 }
291
292 /*
293 * acpi_pci_irq_lookup
294 * success: return IRQ >= 0
295 * failure: return -1
296 */
297 static int
298 acpi_pci_irq_lookup(struct pci_bus *bus,
299 int device,
300 int pin,
301 int *triggering,
302 int *polarity, char **link, irq_lookup_func func)
303 {
304 struct acpi_prt_entry *entry = NULL;
305 int segment = pci_domain_nr(bus);
306 int bus_nr = bus->number;
307 int ret;
308
309
310 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
311 "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
312 segment, bus_nr, device, ('A' + pin)));
313
314 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
315 if (!entry) {
316 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
317 return -1;
318 }
319
320 ret = func(entry, triggering, polarity, link);
321 return ret;
322 }
323
324 /*
325 * acpi_pci_irq_derive
326 * success: return IRQ >= 0
327 * failure: return < 0
328 */
329 static int
330 acpi_pci_irq_derive(struct pci_dev *dev,
331 int pin,
332 int *triggering,
333 int *polarity, char **link, irq_lookup_func func)
334 {
335 struct pci_dev *bridge = dev;
336 int irq = -1;
337 u8 bridge_pin = 0;
338
339
340 if (!dev)
341 return -EINVAL;
342
343 /*
344 * Attempt to derive an IRQ for this device from a parent bridge's
345 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
346 */
347 while (irq < 0 && bridge->bus->self) {
348 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
349 bridge = bridge->bus->self;
350
351 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
352 /* PC card has the same IRQ as its cardbridge */
353 bridge_pin = bridge->pin;
354 if (!bridge_pin) {
355 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
356 "No interrupt pin configured for device %s\n",
357 pci_name(bridge)));
358 return -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, triggering, polarity,
367 link, func);
368 }
369
370 if (irq < 0) {
371 printk(KERN_WARNING PREFIX "Unable to derive IRQ for device %s\n",
372 pci_name(dev));
373 return -1;
374 }
375
376 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
377 irq, pci_name(dev), pci_name(bridge)));
378
379 return irq;
380 }
381
382 /*
383 * acpi_pci_irq_enable
384 * success: return 0
385 * failure: return < 0
386 */
387
388 int acpi_pci_irq_enable(struct pci_dev *dev)
389 {
390 int irq = 0;
391 u8 pin = 0;
392 int triggering = ACPI_LEVEL_SENSITIVE;
393 int polarity = ACPI_ACTIVE_LOW;
394 char *link = NULL;
395 int rc;
396
397
398 if (!dev)
399 return -EINVAL;
400
401 pin = dev->pin;
402 if (!pin) {
403 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
404 "No interrupt pin configured for device %s\n",
405 pci_name(dev)));
406 return 0;
407 }
408 pin--;
409
410 if (!dev->bus) {
411 printk(KERN_ERR PREFIX "Invalid (NULL) 'bus' field\n");
412 return -ENODEV;
413 }
414
415 /*
416 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT
417 * values override any BIOS-assigned IRQs set during boot.
418 */
419 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
420 &triggering, &polarity, &link,
421 acpi_pci_allocate_irq);
422
423 /*
424 * If no PRT entry was found, we'll try to derive an IRQ from the
425 * device's parent bridge.
426 */
427 if (irq < 0)
428 irq = acpi_pci_irq_derive(dev, pin, &triggering,
429 &polarity, &link,
430 acpi_pci_allocate_irq);
431
432 /*
433 * No IRQ known to the ACPI subsystem - maybe the BIOS /
434 * driver reported one, then use it. Exit in any case.
435 */
436 if (irq < 0) {
437 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
438 pci_name(dev), ('A' + pin));
439 /* Interrupt Line values above 0xF are forbidden */
440 if (dev->irq > 0 && (dev->irq <= 0xF)) {
441 printk(" - using IRQ %d\n", dev->irq);
442 acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
443 ACPI_ACTIVE_LOW);
444 return 0;
445 } else {
446 printk("\n");
447 return 0;
448 }
449 }
450
451 rc = acpi_register_gsi(irq, triggering, polarity);
452 if (rc < 0) {
453 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
454 "to register GSI\n", pci_name(dev), ('A' + pin));
455 return rc;
456 }
457 dev->irq = rc;
458
459 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
460 pci_name(dev), 'A' + pin);
461
462 if (link)
463 printk("Link [%s] -> ", link);
464
465 printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
466 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
467 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
468
469 return 0;
470 }
471
472 EXPORT_SYMBOL(acpi_pci_irq_enable);
473
474 /* FIXME: implement x86/x86_64 version */
475 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
476 {
477 }
478
479 void acpi_pci_irq_disable(struct pci_dev *dev)
480 {
481 int gsi = 0;
482 u8 pin = 0;
483 int triggering = ACPI_LEVEL_SENSITIVE;
484 int polarity = ACPI_ACTIVE_LOW;
485
486
487 if (!dev || !dev->bus)
488 return;
489
490 pin = dev->pin;
491 if (!pin)
492 return;
493 pin--;
494
495 /*
496 * First we check the PCI IRQ routing table (PRT) for an IRQ.
497 */
498 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
499 &triggering, &polarity, NULL,
500 acpi_pci_free_irq);
501 /*
502 * If no PRT entry was found, we'll try to derive an IRQ from the
503 * device's parent bridge.
504 */
505 if (gsi < 0)
506 gsi = acpi_pci_irq_derive(dev, pin,
507 &triggering, &polarity, NULL,
508 acpi_pci_free_irq);
509 if (gsi < 0)
510 return;
511
512 /*
513 * TBD: It might be worth clearing dev->irq by magic constant
514 * (e.g. PCI_UNDEFINED_IRQ).
515 */
516
517 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
518 pci_name(dev));
519
520 acpi_unregister_gsi(gsi);
521
522 return;
523 }
Linux with added FPC-III support