xref: /openbmc/linux/drivers/acpi/pci_irq.c (revision 37185b33)
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, struct pci_bus *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 = pci_domain_nr(bus);
202 	entry->id.bus = bus->number;
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, struct pci_bus *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, 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(struct pci_bus *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 	       pci_domain_nr(bus), bus->number);
292 	spin_lock(&acpi_prt_lock);
293 	list_for_each_entry_safe(entry, tmp, &acpi_prt_list, list) {
294 		if (pci_domain_nr(bus) == entry->id.segment
295 			&& bus->number == entry->id.bus) {
296 			list_del(&entry->list);
297 			kfree(entry);
298 		}
299 	}
300 	spin_unlock(&acpi_prt_lock);
301 }
302 
303 /* --------------------------------------------------------------------------
304                           PCI Interrupt Routing Support
305    -------------------------------------------------------------------------- */
306 #ifdef CONFIG_X86_IO_APIC
307 extern int noioapicquirk;
308 extern int noioapicreroute;
309 
310 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
311 {
312 	struct pci_bus *bus_it;
313 
314 	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
315 		if (!bus_it->self)
316 			return 0;
317 		if (bus_it->self->irq_reroute_variant)
318 			return bus_it->self->irq_reroute_variant;
319 	}
320 	return 0;
321 }
322 
323 /*
324  * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
325  * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
326  * during interrupt handling). When this INTx generation cannot be disabled,
327  * we reroute these interrupts to their legacy equivalent to get rid of
328  * spurious interrupts.
329  */
330 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
331 				       struct acpi_prt_entry *entry)
332 {
333 	if (noioapicquirk || noioapicreroute) {
334 		return 0;
335 	} else {
336 		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
337 		case 0:
338 			/* no rerouting necessary */
339 			return 0;
340 		case INTEL_IRQ_REROUTE_VARIANT:
341 			/*
342 			 * Remap according to INTx routing table in 6700PXH
343 			 * specs, intel order number 302628-002, section
344 			 * 2.15.2. Other chipsets (80332, ...) have the same
345 			 * mapping and are handled here as well.
346 			 */
347 			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
348 				 "IRQ %d\n", entry->index,
349 				 (entry->index % 4) + 16);
350 			entry->index = (entry->index % 4) + 16;
351 			return 1;
352 		default:
353 			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
354 				 "IRQ: unknown mapping\n", entry->index);
355 			return -1;
356 		}
357 	}
358 }
359 #endif /* CONFIG_X86_IO_APIC */
360 
361 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
362 {
363 	struct acpi_prt_entry *entry;
364 	struct pci_dev *bridge;
365 	u8 bridge_pin, orig_pin = pin;
366 
367 	entry = acpi_pci_irq_find_prt_entry(dev, pin);
368 	if (entry) {
369 #ifdef CONFIG_X86_IO_APIC
370 		acpi_reroute_boot_interrupt(dev, entry);
371 #endif /* CONFIG_X86_IO_APIC */
372 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
373 				  pci_name(dev), pin_name(pin)));
374 		return entry;
375 	}
376 
377 	/*
378 	 * Attempt to derive an IRQ for this device from a parent bridge's
379 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
380 	 */
381 	bridge = dev->bus->self;
382 	while (bridge) {
383 		pin = pci_swizzle_interrupt_pin(dev, pin);
384 
385 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
386 			/* PC card has the same IRQ as its cardbridge */
387 			bridge_pin = bridge->pin;
388 			if (!bridge_pin) {
389 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
390 						  "No interrupt pin configured for device %s\n",
391 						  pci_name(bridge)));
392 				return NULL;
393 			}
394 			pin = bridge_pin;
395 		}
396 
397 		entry = acpi_pci_irq_find_prt_entry(bridge, pin);
398 		if (entry) {
399 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
400 					 "Derived GSI for %s INT %c from %s\n",
401 					 pci_name(dev), pin_name(orig_pin),
402 					 pci_name(bridge)));
403 			return entry;
404 		}
405 
406 		dev = bridge;
407 		bridge = dev->bus->self;
408 	}
409 
410 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
411 		 pin_name(orig_pin));
412 	return NULL;
413 }
414 
415 int acpi_pci_irq_enable(struct pci_dev *dev)
416 {
417 	struct acpi_prt_entry *entry;
418 	int gsi;
419 	u8 pin;
420 	int triggering = ACPI_LEVEL_SENSITIVE;
421 	int polarity = ACPI_ACTIVE_LOW;
422 	char *link = NULL;
423 	char link_desc[16];
424 	int rc;
425 
426 	pin = dev->pin;
427 	if (!pin) {
428 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
429 				  "No interrupt pin configured for device %s\n",
430 				  pci_name(dev)));
431 		return 0;
432 	}
433 
434 	entry = acpi_pci_irq_lookup(dev, pin);
435 	if (!entry) {
436 		/*
437 		 * IDE legacy mode controller IRQs are magic. Why do compat
438 		 * extensions always make such a nasty mess.
439 		 */
440 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
441 				(dev->class & 0x05) == 0)
442 			return 0;
443 	}
444 
445 	if (entry) {
446 		if (entry->link)
447 			gsi = acpi_pci_link_allocate_irq(entry->link,
448 							 entry->index,
449 							 &triggering, &polarity,
450 							 &link);
451 		else
452 			gsi = entry->index;
453 	} else
454 		gsi = -1;
455 
456 	/*
457 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
458 	 * driver reported one, then use it. Exit in any case.
459 	 */
460 	if (gsi < 0) {
461 		u32 dev_gsi;
462 		dev_warn(&dev->dev, "PCI INT %c: no GSI", pin_name(pin));
463 		/* Interrupt Line values above 0xF are forbidden */
464 		if (dev->irq > 0 && (dev->irq <= 0xF) &&
465 		    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
466 			printk(" - using ISA IRQ %d\n", dev->irq);
467 			acpi_register_gsi(&dev->dev, dev_gsi,
468 					  ACPI_LEVEL_SENSITIVE,
469 					  ACPI_ACTIVE_LOW);
470 			return 0;
471 		} else {
472 			printk("\n");
473 			return 0;
474 		}
475 	}
476 
477 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
478 	if (rc < 0) {
479 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
480 			 pin_name(pin));
481 		return rc;
482 	}
483 	dev->irq = rc;
484 
485 	if (link)
486 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
487 	else
488 		link_desc[0] = '\0';
489 
490 	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
491 		pin_name(pin), link_desc, gsi,
492 		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
493 		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
494 
495 	return 0;
496 }
497 
498 /* FIXME: implement x86/x86_64 version */
499 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
500 {
501 }
502 
503 void acpi_pci_irq_disable(struct pci_dev *dev)
504 {
505 	struct acpi_prt_entry *entry;
506 	int gsi;
507 	u8 pin;
508 
509 	pin = dev->pin;
510 	if (!pin)
511 		return;
512 
513 	entry = acpi_pci_irq_lookup(dev, pin);
514 	if (!entry)
515 		return;
516 
517 	if (entry->link)
518 		gsi = acpi_pci_link_free_irq(entry->link);
519 	else
520 		gsi = entry->index;
521 
522 	/*
523 	 * TBD: It might be worth clearing dev->irq by magic constant
524 	 * (e.g. PCI_UNDEFINED_IRQ).
525 	 */
526 
527 	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
528 	acpi_unregister_gsi(gsi);
529 }
530