pci_irq.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 
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#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;
394	extern int		via_interrupt_line_quirk;
395	char			*link = NULL;
396
397	ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
398
399	if (!dev)
400		return_VALUE(-EINVAL);
401
402	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
403	if (!pin) {
404		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", pci_name(dev)));
405		return_VALUE(0);
406	}
407	pin--;
408
409	if (!dev->bus) {
410		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n"));
411		return_VALUE(-ENODEV);
412	}
413
414	/*
415	 * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
416	 * values override any BIOS-assigned IRQs set during boot.
417	 */
418 	irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
419		&edge_level, &active_high_low, &link);
420
421	/*
422	 * If no PRT entry was found, we'll try to derive an IRQ from the
423	 * device's parent bridge.
424	 */
425	if (irq < 0)
426 		irq = acpi_pci_irq_derive(dev, pin, &edge_level,
427			&active_high_low, &link);
428
429	/*
430	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
431	 * driver reported one, then use it. Exit in any case.
432	 */
433	if (irq < 0) {
434		printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
435			pci_name(dev), ('A' + pin));
436		/* Interrupt Line values above 0xF are forbidden */
437		if (dev->irq >= 0 && (dev->irq <= 0xF)) {
438			printk(" - using IRQ %d\n", dev->irq);
439			return_VALUE(0);
440		}
441		else {
442			printk("\n");
443			return_VALUE(0);
444		}
445 	}
446
447	if (via_interrupt_line_quirk)
448		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq & 15);
449
450	dev->irq = acpi_register_gsi(irq, edge_level, active_high_low);
451
452	printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
453		pci_name(dev), 'A' + pin);
454
455	if (link)
456		printk("Link [%s] -> ", link);
457
458	printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
459		(edge_level == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
460		(active_high_low == ACPI_ACTIVE_LOW) ? "low" : "high",
461		dev->irq);
462
463	return_VALUE(0);
464}
465EXPORT_SYMBOL(acpi_pci_irq_enable);
466
467
468#ifdef CONFIG_ACPI_DEALLOCATE_IRQ
469void
470acpi_pci_irq_disable (
471	struct pci_dev		*dev)
472{
473	int			gsi = 0;
474	u8			pin = 0;
475	int			edge_level = ACPI_LEVEL_SENSITIVE;
476	int			active_high_low = ACPI_ACTIVE_LOW;
477
478	ACPI_FUNCTION_TRACE("acpi_pci_irq_disable");
479
480	if (!dev)
481		return_VOID;
482
483	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
484	if (!pin)
485		return_VOID;
486	pin--;
487
488	if (!dev->bus)
489		return_VOID;
490
491	/*
492	 * First we check the PCI IRQ routing table (PRT) for an IRQ.
493	 */
494 	gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
495				  &edge_level, &active_high_low, NULL);
496	/*
497	 * If no PRT entry was found, we'll try to derive an IRQ from the
498	 * device's parent bridge.
499	 */
500	if (gsi < 0)
501 		gsi = acpi_pci_irq_derive(dev, pin,
502					  &edge_level, &active_high_low, NULL);
503	if (gsi < 0)
504		return_VOID;
505
506	/*
507	 * TBD: It might be worth clearing dev->irq by magic constant
508	 * (e.g. PCI_UNDEFINED_IRQ).
509	 */
510
511	printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
512	       pci_name(dev));
513
514	acpi_unregister_gsi(gsi);
515
516	return_VOID;
517}
518#endif /* CONFIG_ACPI_DEALLOCATE_IRQ */
519