xref: /linux/drivers/acpi/pci_irq.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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  *  (c) Copyright 2008 Hewlett-Packard Development Company, L.P.
8  *	Bjorn Helgaas <bjorn.helgaas@hp.com>
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or (at
15  *  your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful, but
18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20  *  General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License along
23  *  with this program; if not, write to the Free Software Foundation, Inc.,
24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25  *
26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27  */
28 
29 
30 #include <linux/dmi.h>
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/init.h>
34 #include <linux/types.h>
35 #include <linux/spinlock.h>
36 #include <linux/pm.h>
37 #include <linux/pci.h>
38 #include <linux/acpi.h>
39 #include <linux/slab.h>
40 #include <acpi/acpi_bus.h>
41 #include <acpi/acpi_drivers.h>
42 
43 #define PREFIX "ACPI: "
44 
45 #define _COMPONENT		ACPI_PCI_COMPONENT
46 ACPI_MODULE_NAME("pci_irq");
47 
48 struct acpi_prt_entry {
49 	struct list_head	list;
50 	struct acpi_pci_id	id;
51 	u8			pin;
52 	acpi_handle		link;
53 	u32			index;		/* GSI, or link _CRS index */
54 };
55 
56 static LIST_HEAD(acpi_prt_list);
57 static DEFINE_SPINLOCK(acpi_prt_lock);
58 
59 static inline char pin_name(int pin)
60 {
61 	return 'A' + pin - 1;
62 }
63 
64 /* --------------------------------------------------------------------------
65                          PCI IRQ Routing Table (PRT) Support
66    -------------------------------------------------------------------------- */
67 
68 static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
69 							  int pin)
70 {
71 	struct acpi_prt_entry *entry;
72 	int segment = pci_domain_nr(dev->bus);
73 	int bus = dev->bus->number;
74 	int device = PCI_SLOT(dev->devfn);
75 
76 	spin_lock(&acpi_prt_lock);
77 	list_for_each_entry(entry, &acpi_prt_list, list) {
78 		if ((segment == entry->id.segment)
79 		    && (bus == entry->id.bus)
80 		    && (device == entry->id.device)
81 		    && (pin == entry->pin)) {
82 			spin_unlock(&acpi_prt_lock);
83 			return entry;
84 		}
85 	}
86 	spin_unlock(&acpi_prt_lock);
87 	return NULL;
88 }
89 
90 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
91 static const struct dmi_system_id medion_md9580[] = {
92 	{
93 		.ident = "Medion MD9580-F laptop",
94 		.matches = {
95 			DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
96 			DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
97 		},
98 	},
99 	{ }
100 };
101 
102 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
103 static const struct dmi_system_id dell_optiplex[] = {
104 	{
105 		.ident = "Dell Optiplex GX1",
106 		.matches = {
107 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
108 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
109 		},
110 	},
111 	{ }
112 };
113 
114 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
115 static const struct dmi_system_id hp_t5710[] = {
116 	{
117 		.ident = "HP t5710",
118 		.matches = {
119 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
120 			DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
121 			DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
122 		},
123 	},
124 	{ }
125 };
126 
127 struct prt_quirk {
128 	const struct dmi_system_id *system;
129 	unsigned int		segment;
130 	unsigned int		bus;
131 	unsigned int		device;
132 	unsigned char		pin;
133 	const char		*source;	/* according to BIOS */
134 	const char		*actual_source;
135 };
136 
137 #define PCI_INTX_PIN(c)		(c - 'A' + 1)
138 
139 /*
140  * These systems have incorrect _PRT entries.  The BIOS claims the PCI
141  * interrupt at the listed segment/bus/device/pin is connected to the first
142  * link device, but it is actually connected to the second.
143  */
144 static const struct prt_quirk prt_quirks[] = {
145 	{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
146 		"\\_SB_.PCI0.ISA_.LNKA",
147 		"\\_SB_.PCI0.ISA_.LNKB"},
148 	{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
149 		"\\_SB_.LNKB",
150 		"\\_SB_.LNKA"},
151 	{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
152 		"\\_SB_.PCI0.LNK1",
153 		"\\_SB_.PCI0.LNK3"},
154 };
155 
156 static void do_prt_fixups(struct acpi_prt_entry *entry,
157 			  struct acpi_pci_routing_table *prt)
158 {
159 	int i;
160 	const struct prt_quirk *quirk;
161 
162 	for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
163 		quirk = &prt_quirks[i];
164 
165 		/* All current quirks involve link devices, not GSIs */
166 		if (!prt->source)
167 			continue;
168 
169 		if (dmi_check_system(quirk->system) &&
170 		    entry->id.segment == quirk->segment &&
171 		    entry->id.bus == quirk->bus &&
172 		    entry->id.device == quirk->device &&
173 		    entry->pin == quirk->pin &&
174 		    !strcmp(prt->source, quirk->source) &&
175 		    strlen(prt->source) >= strlen(quirk->actual_source)) {
176 			printk(KERN_WARNING PREFIX "firmware reports "
177 				"%04x:%02x:%02x PCI INT %c connected to %s; "
178 				"changing to %s\n",
179 				entry->id.segment, entry->id.bus,
180 				entry->id.device, pin_name(entry->pin),
181 				prt->source, quirk->actual_source);
182 			strcpy(prt->source, quirk->actual_source);
183 		}
184 	}
185 }
186 
187 static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
188 				  struct acpi_pci_routing_table *prt)
189 {
190 	struct acpi_prt_entry *entry;
191 
192 	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
193 	if (!entry)
194 		return -ENOMEM;
195 
196 	/*
197 	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
198 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
199 	 * it here.
200 	 */
201 	entry->id.segment = segment;
202 	entry->id.bus = bus;
203 	entry->id.device = (prt->address >> 16) & 0xFFFF;
204 	entry->pin = prt->pin + 1;
205 
206 	do_prt_fixups(entry, prt);
207 
208 	entry->index = prt->source_index;
209 
210 	/*
211 	 * Type 1: Dynamic
212 	 * ---------------
213 	 * The 'source' field specifies the PCI interrupt link device used to
214 	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
215 	 * indicates which resource descriptor in the resource template (of
216 	 * the link device) this interrupt is allocated from.
217 	 *
218 	 * NOTE: Don't query the Link Device for IRQ information at this time
219 	 *       because Link Device enumeration may not have occurred yet
220 	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
221 	 *       namespace).
222 	 */
223 	if (prt->source[0])
224 		acpi_get_handle(handle, prt->source, &entry->link);
225 
226 	/*
227 	 * Type 2: Static
228 	 * --------------
229 	 * The 'source' field is NULL, and the 'source_index' field specifies
230 	 * the IRQ value, which is hardwired to specific interrupt inputs on
231 	 * the interrupt controller.
232 	 */
233 
234 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
235 			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
236 			      entry->id.segment, entry->id.bus,
237 			      entry->id.device, pin_name(entry->pin),
238 			      prt->source, entry->index));
239 
240 	spin_lock(&acpi_prt_lock);
241 	list_add_tail(&entry->list, &acpi_prt_list);
242 	spin_unlock(&acpi_prt_lock);
243 
244 	return 0;
245 }
246 
247 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
248 {
249 	acpi_status status;
250 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
251 	struct acpi_pci_routing_table *entry;
252 
253 	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
254 	status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
255 	if (ACPI_FAILURE(status))
256 		return -ENODEV;
257 
258 	printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
259 	       (char *) buffer.pointer);
260 
261 	kfree(buffer.pointer);
262 
263 	buffer.length = ACPI_ALLOCATE_BUFFER;
264 	buffer.pointer = NULL;
265 
266 	status = acpi_get_irq_routing_table(handle, &buffer);
267 	if (ACPI_FAILURE(status)) {
268 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
269 				acpi_format_exception(status)));
270 		kfree(buffer.pointer);
271 		return -ENODEV;
272 	}
273 
274 	entry = buffer.pointer;
275 	while (entry && (entry->length > 0)) {
276 		acpi_pci_irq_add_entry(handle, segment, bus, entry);
277 		entry = (struct acpi_pci_routing_table *)
278 		    ((unsigned long)entry + entry->length);
279 	}
280 
281 	kfree(buffer.pointer);
282 	return 0;
283 }
284 
285 void acpi_pci_irq_del_prt(int segment, int bus)
286 {
287 	struct acpi_prt_entry *entry, *tmp;
288 
289 	printk(KERN_DEBUG
290 	       "ACPI: Delete PCI Interrupt Routing Table for %04x:%02x\n",
291 	       segment, bus);
292 	spin_lock(&acpi_prt_lock);
293 	list_for_each_entry_safe(entry, tmp, &acpi_prt_list, list) {
294 		if (segment == entry->id.segment && bus == entry->id.bus) {
295 			list_del(&entry->list);
296 			kfree(entry);
297 		}
298 	}
299 	spin_unlock(&acpi_prt_lock);
300 }
301 
302 /* --------------------------------------------------------------------------
303                           PCI Interrupt Routing Support
304    -------------------------------------------------------------------------- */
305 #ifdef CONFIG_X86_IO_APIC
306 extern int noioapicquirk;
307 extern int noioapicreroute;
308 
309 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
310 {
311 	struct pci_bus *bus_it;
312 
313 	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
314 		if (!bus_it->self)
315 			return 0;
316 		if (bus_it->self->irq_reroute_variant)
317 			return bus_it->self->irq_reroute_variant;
318 	}
319 	return 0;
320 }
321 
322 /*
323  * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
324  * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
325  * during interrupt handling). When this INTx generation cannot be disabled,
326  * we reroute these interrupts to their legacy equivalent to get rid of
327  * spurious interrupts.
328  */
329 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
330 				       struct acpi_prt_entry *entry)
331 {
332 	if (noioapicquirk || noioapicreroute) {
333 		return 0;
334 	} else {
335 		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
336 		case 0:
337 			/* no rerouting necessary */
338 			return 0;
339 		case INTEL_IRQ_REROUTE_VARIANT:
340 			/*
341 			 * Remap according to INTx routing table in 6700PXH
342 			 * specs, intel order number 302628-002, section
343 			 * 2.15.2. Other chipsets (80332, ...) have the same
344 			 * mapping and are handled here as well.
345 			 */
346 			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
347 				 "IRQ %d\n", entry->index,
348 				 (entry->index % 4) + 16);
349 			entry->index = (entry->index % 4) + 16;
350 			return 1;
351 		default:
352 			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
353 				 "IRQ: unknown mapping\n", entry->index);
354 			return -1;
355 		}
356 	}
357 }
358 #endif /* CONFIG_X86_IO_APIC */
359 
360 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
361 {
362 	struct acpi_prt_entry *entry;
363 	struct pci_dev *bridge;
364 	u8 bridge_pin, orig_pin = pin;
365 
366 	entry = acpi_pci_irq_find_prt_entry(dev, pin);
367 	if (entry) {
368 #ifdef CONFIG_X86_IO_APIC
369 		acpi_reroute_boot_interrupt(dev, entry);
370 #endif /* CONFIG_X86_IO_APIC */
371 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
372 				  pci_name(dev), pin_name(pin)));
373 		return entry;
374 	}
375 
376 	/*
377 	 * Attempt to derive an IRQ for this device from a parent bridge's
378 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
379 	 */
380 	bridge = dev->bus->self;
381 	while (bridge) {
382 		pin = pci_swizzle_interrupt_pin(dev, pin);
383 
384 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
385 			/* PC card has the same IRQ as its cardbridge */
386 			bridge_pin = bridge->pin;
387 			if (!bridge_pin) {
388 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
389 						  "No interrupt pin configured for device %s\n",
390 						  pci_name(bridge)));
391 				return NULL;
392 			}
393 			pin = bridge_pin;
394 		}
395 
396 		entry = acpi_pci_irq_find_prt_entry(bridge, pin);
397 		if (entry) {
398 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
399 					 "Derived GSI for %s INT %c from %s\n",
400 					 pci_name(dev), pin_name(orig_pin),
401 					 pci_name(bridge)));
402 			return entry;
403 		}
404 
405 		dev = bridge;
406 		bridge = dev->bus->self;
407 	}
408 
409 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
410 		 pin_name(orig_pin));
411 	return NULL;
412 }
413 
414 int acpi_pci_irq_enable(struct pci_dev *dev)
415 {
416 	struct acpi_prt_entry *entry;
417 	int gsi;
418 	u8 pin;
419 	int triggering = ACPI_LEVEL_SENSITIVE;
420 	int polarity = ACPI_ACTIVE_LOW;
421 	char *link = NULL;
422 	char link_desc[16];
423 	int rc;
424 
425 	pin = dev->pin;
426 	if (!pin) {
427 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
428 				  "No interrupt pin configured for device %s\n",
429 				  pci_name(dev)));
430 		return 0;
431 	}
432 
433 	entry = acpi_pci_irq_lookup(dev, pin);
434 	if (!entry) {
435 		/*
436 		 * IDE legacy mode controller IRQs are magic. Why do compat
437 		 * extensions always make such a nasty mess.
438 		 */
439 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
440 				(dev->class & 0x05) == 0)
441 			return 0;
442 	}
443 
444 	if (entry) {
445 		if (entry->link)
446 			gsi = acpi_pci_link_allocate_irq(entry->link,
447 							 entry->index,
448 							 &triggering, &polarity,
449 							 &link);
450 		else
451 			gsi = entry->index;
452 	} else
453 		gsi = -1;
454 
455 	/*
456 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
457 	 * driver reported one, then use it. Exit in any case.
458 	 */
459 	if (gsi < 0) {
460 		u32 dev_gsi;
461 		/* Interrupt Line values above 0xF are forbidden */
462 		if (dev->irq > 0 && (dev->irq <= 0xF) &&
463 		    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
464 			dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
465 				 pin_name(pin), dev->irq);
466 			acpi_register_gsi(&dev->dev, dev_gsi,
467 					  ACPI_LEVEL_SENSITIVE,
468 					  ACPI_ACTIVE_LOW);
469 		} else {
470 			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
471 				 pin_name(pin));
472 		}
473 		return 0;
474 	}
475 
476 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
477 	if (rc < 0) {
478 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
479 			 pin_name(pin));
480 		return rc;
481 	}
482 	dev->irq = rc;
483 
484 	if (link)
485 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
486 	else
487 		link_desc[0] = '\0';
488 
489 	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
490 		pin_name(pin), link_desc, gsi,
491 		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
492 		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
493 
494 	return 0;
495 }
496 
497 void acpi_pci_irq_disable(struct pci_dev *dev)
498 {
499 	struct acpi_prt_entry *entry;
500 	int gsi;
501 	u8 pin;
502 
503 	pin = dev->pin;
504 	if (!pin)
505 		return;
506 
507 	entry = acpi_pci_irq_lookup(dev, pin);
508 	if (!entry)
509 		return;
510 
511 	if (entry->link)
512 		gsi = acpi_pci_link_free_irq(entry->link);
513 	else
514 		gsi = entry->index;
515 
516 	/*
517 	 * TBD: It might be worth clearing dev->irq by magic constant
518 	 * (e.g. PCI_UNDEFINED_IRQ).
519 	 */
520 
521 	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
522 	acpi_unregister_gsi(gsi);
523 }
524