xref: /linux/drivers/acpi/pci_irq.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23  */
24 
25 
26 #include <linux/dmi.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <linux/spinlock.h>
32 #include <linux/pm.h>
33 #include <linux/pci.h>
34 #include <linux/acpi.h>
35 #include <linux/slab.h>
36 
37 #define PREFIX "ACPI: "
38 
39 #define _COMPONENT		ACPI_PCI_COMPONENT
40 ACPI_MODULE_NAME("pci_irq");
41 
42 struct acpi_prt_entry {
43 	struct acpi_pci_id	id;
44 	u8			pin;
45 	acpi_handle		link;
46 	u32			index;		/* GSI, or link _CRS index */
47 };
48 
49 static inline char pin_name(int pin)
50 {
51 	return 'A' + pin - 1;
52 }
53 
54 /* --------------------------------------------------------------------------
55                          PCI IRQ Routing Table (PRT) Support
56    -------------------------------------------------------------------------- */
57 
58 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
59 static const struct dmi_system_id medion_md9580[] = {
60 	{
61 		.ident = "Medion MD9580-F laptop",
62 		.matches = {
63 			DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
64 			DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
65 		},
66 	},
67 	{ }
68 };
69 
70 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
71 static const struct dmi_system_id dell_optiplex[] = {
72 	{
73 		.ident = "Dell Optiplex GX1",
74 		.matches = {
75 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
76 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
77 		},
78 	},
79 	{ }
80 };
81 
82 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
83 static const struct dmi_system_id hp_t5710[] = {
84 	{
85 		.ident = "HP t5710",
86 		.matches = {
87 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
88 			DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
89 			DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
90 		},
91 	},
92 	{ }
93 };
94 
95 struct prt_quirk {
96 	const struct dmi_system_id *system;
97 	unsigned int		segment;
98 	unsigned int		bus;
99 	unsigned int		device;
100 	unsigned char		pin;
101 	const char		*source;	/* according to BIOS */
102 	const char		*actual_source;
103 };
104 
105 #define PCI_INTX_PIN(c)		(c - 'A' + 1)
106 
107 /*
108  * These systems have incorrect _PRT entries.  The BIOS claims the PCI
109  * interrupt at the listed segment/bus/device/pin is connected to the first
110  * link device, but it is actually connected to the second.
111  */
112 static const struct prt_quirk prt_quirks[] = {
113 	{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
114 		"\\_SB_.PCI0.ISA_.LNKA",
115 		"\\_SB_.PCI0.ISA_.LNKB"},
116 	{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
117 		"\\_SB_.LNKB",
118 		"\\_SB_.LNKA"},
119 	{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
120 		"\\_SB_.PCI0.LNK1",
121 		"\\_SB_.PCI0.LNK3"},
122 };
123 
124 static void do_prt_fixups(struct acpi_prt_entry *entry,
125 			  struct acpi_pci_routing_table *prt)
126 {
127 	int i;
128 	const struct prt_quirk *quirk;
129 
130 	for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
131 		quirk = &prt_quirks[i];
132 
133 		/* All current quirks involve link devices, not GSIs */
134 		if (dmi_check_system(quirk->system) &&
135 		    entry->id.segment == quirk->segment &&
136 		    entry->id.bus == quirk->bus &&
137 		    entry->id.device == quirk->device &&
138 		    entry->pin == quirk->pin &&
139 		    !strcmp(prt->source, quirk->source) &&
140 		    strlen(prt->source) >= strlen(quirk->actual_source)) {
141 			printk(KERN_WARNING PREFIX "firmware reports "
142 				"%04x:%02x:%02x PCI INT %c connected to %s; "
143 				"changing to %s\n",
144 				entry->id.segment, entry->id.bus,
145 				entry->id.device, pin_name(entry->pin),
146 				prt->source, quirk->actual_source);
147 			strcpy(prt->source, quirk->actual_source);
148 		}
149 	}
150 }
151 
152 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
153 				  int pin, struct acpi_pci_routing_table *prt,
154 				  struct acpi_prt_entry **entry_ptr)
155 {
156 	int segment = pci_domain_nr(dev->bus);
157 	int bus = dev->bus->number;
158 	int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn);
159 	struct acpi_prt_entry *entry;
160 
161 	if (((prt->address >> 16) & 0xffff) != device ||
162 	    prt->pin + 1 != pin)
163 		return -ENODEV;
164 
165 	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
166 	if (!entry)
167 		return -ENOMEM;
168 
169 	/*
170 	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
171 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
172 	 * it here.
173 	 */
174 	entry->id.segment = segment;
175 	entry->id.bus = bus;
176 	entry->id.device = (prt->address >> 16) & 0xFFFF;
177 	entry->pin = prt->pin + 1;
178 
179 	do_prt_fixups(entry, prt);
180 
181 	entry->index = prt->source_index;
182 
183 	/*
184 	 * Type 1: Dynamic
185 	 * ---------------
186 	 * The 'source' field specifies the PCI interrupt link device used to
187 	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
188 	 * indicates which resource descriptor in the resource template (of
189 	 * the link device) this interrupt is allocated from.
190 	 *
191 	 * NOTE: Don't query the Link Device for IRQ information at this time
192 	 *       because Link Device enumeration may not have occurred yet
193 	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
194 	 *       namespace).
195 	 */
196 	if (prt->source[0])
197 		acpi_get_handle(handle, prt->source, &entry->link);
198 
199 	/*
200 	 * Type 2: Static
201 	 * --------------
202 	 * The 'source' field is NULL, and the 'source_index' field specifies
203 	 * the IRQ value, which is hardwired to specific interrupt inputs on
204 	 * the interrupt controller.
205 	 */
206 
207 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
208 			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
209 			      entry->id.segment, entry->id.bus,
210 			      entry->id.device, pin_name(entry->pin),
211 			      prt->source, entry->index));
212 
213 	*entry_ptr = entry;
214 
215 	return 0;
216 }
217 
218 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
219 			  int pin, struct acpi_prt_entry **entry_ptr)
220 {
221 	acpi_status status;
222 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
223 	struct acpi_pci_routing_table *entry;
224 	acpi_handle handle = NULL;
225 
226 	if (dev->bus->bridge)
227 		handle = ACPI_HANDLE(dev->bus->bridge);
228 
229 	if (!handle)
230 		return -ENODEV;
231 
232 	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
233 	status = acpi_get_irq_routing_table(handle, &buffer);
234 	if (ACPI_FAILURE(status)) {
235 		kfree(buffer.pointer);
236 		return -ENODEV;
237 	}
238 
239 	entry = buffer.pointer;
240 	while (entry && (entry->length > 0)) {
241 		if (!acpi_pci_irq_check_entry(handle, dev, pin,
242 						 entry, entry_ptr))
243 			break;
244 		entry = (struct acpi_pci_routing_table *)
245 		    ((unsigned long)entry + entry->length);
246 	}
247 
248 	kfree(buffer.pointer);
249 	return 0;
250 }
251 
252 /* --------------------------------------------------------------------------
253                           PCI Interrupt Routing Support
254    -------------------------------------------------------------------------- */
255 #ifdef CONFIG_X86_IO_APIC
256 extern int noioapicquirk;
257 extern int noioapicreroute;
258 
259 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
260 {
261 	struct pci_bus *bus_it;
262 
263 	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
264 		if (!bus_it->self)
265 			return 0;
266 		if (bus_it->self->irq_reroute_variant)
267 			return bus_it->self->irq_reroute_variant;
268 	}
269 	return 0;
270 }
271 
272 /*
273  * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
274  * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
275  * during interrupt handling). When this INTx generation cannot be disabled,
276  * we reroute these interrupts to their legacy equivalent to get rid of
277  * spurious interrupts.
278  */
279 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
280 				       struct acpi_prt_entry *entry)
281 {
282 	if (noioapicquirk || noioapicreroute) {
283 		return 0;
284 	} else {
285 		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
286 		case 0:
287 			/* no rerouting necessary */
288 			return 0;
289 		case INTEL_IRQ_REROUTE_VARIANT:
290 			/*
291 			 * Remap according to INTx routing table in 6700PXH
292 			 * specs, intel order number 302628-002, section
293 			 * 2.15.2. Other chipsets (80332, ...) have the same
294 			 * mapping and are handled here as well.
295 			 */
296 			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
297 				 "IRQ %d\n", entry->index,
298 				 (entry->index % 4) + 16);
299 			entry->index = (entry->index % 4) + 16;
300 			return 1;
301 		default:
302 			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
303 				 "IRQ: unknown mapping\n", entry->index);
304 			return -1;
305 		}
306 	}
307 }
308 #endif /* CONFIG_X86_IO_APIC */
309 
310 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
311 {
312 	struct acpi_prt_entry *entry = NULL;
313 	struct pci_dev *bridge;
314 	u8 bridge_pin, orig_pin = pin;
315 	int ret;
316 
317 	ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
318 	if (!ret && entry) {
319 #ifdef CONFIG_X86_IO_APIC
320 		acpi_reroute_boot_interrupt(dev, entry);
321 #endif /* CONFIG_X86_IO_APIC */
322 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
323 				  pci_name(dev), pin_name(pin)));
324 		return entry;
325 	}
326 
327 	/*
328 	 * Attempt to derive an IRQ for this device from a parent bridge's
329 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
330 	 */
331 	bridge = dev->bus->self;
332 	while (bridge) {
333 		pin = pci_swizzle_interrupt_pin(dev, pin);
334 
335 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
336 			/* PC card has the same IRQ as its cardbridge */
337 			bridge_pin = bridge->pin;
338 			if (!bridge_pin) {
339 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
340 						  "No interrupt pin configured for device %s\n",
341 						  pci_name(bridge)));
342 				return NULL;
343 			}
344 			pin = bridge_pin;
345 		}
346 
347 		ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
348 		if (!ret && entry) {
349 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
350 					 "Derived GSI for %s INT %c from %s\n",
351 					 pci_name(dev), pin_name(orig_pin),
352 					 pci_name(bridge)));
353 			return entry;
354 		}
355 
356 		dev = bridge;
357 		bridge = dev->bus->self;
358 	}
359 
360 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
361 		 pin_name(orig_pin));
362 	return NULL;
363 }
364 
365 #if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
366 static int acpi_isa_register_gsi(struct pci_dev *dev)
367 {
368 	u32 dev_gsi;
369 
370 	/* Interrupt Line values above 0xF are forbidden */
371 	if (dev->irq > 0 && (dev->irq <= 0xF) &&
372 	    acpi_isa_irq_available(dev->irq) &&
373 	    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
374 		dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
375 			 pin_name(dev->pin), dev->irq);
376 		acpi_register_gsi(&dev->dev, dev_gsi,
377 				  ACPI_LEVEL_SENSITIVE,
378 				  ACPI_ACTIVE_LOW);
379 		return 0;
380 	}
381 	return -EINVAL;
382 }
383 #else
384 static inline int acpi_isa_register_gsi(struct pci_dev *dev)
385 {
386 	return -ENODEV;
387 }
388 #endif
389 
390 int acpi_pci_irq_enable(struct pci_dev *dev)
391 {
392 	struct acpi_prt_entry *entry;
393 	int gsi;
394 	u8 pin;
395 	int triggering = ACPI_LEVEL_SENSITIVE;
396 	int polarity = ACPI_ACTIVE_LOW;
397 	char *link = NULL;
398 	char link_desc[16];
399 	int rc;
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 
409 	if (dev->irq_managed && dev->irq > 0)
410 		return 0;
411 
412 	entry = acpi_pci_irq_lookup(dev, pin);
413 	if (!entry) {
414 		/*
415 		 * IDE legacy mode controller IRQs are magic. Why do compat
416 		 * extensions always make such a nasty mess.
417 		 */
418 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
419 				(dev->class & 0x05) == 0)
420 			return 0;
421 	}
422 
423 	if (entry) {
424 		if (entry->link)
425 			gsi = acpi_pci_link_allocate_irq(entry->link,
426 							 entry->index,
427 							 &triggering, &polarity,
428 							 &link);
429 		else
430 			gsi = entry->index;
431 	} else
432 		gsi = -1;
433 
434 	/*
435 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
436 	 * driver reported one, then use it. Exit in any case.
437 	 */
438 	if (gsi < 0) {
439 		if (acpi_isa_register_gsi(dev))
440 			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
441 				 pin_name(pin));
442 
443 		kfree(entry);
444 		return 0;
445 	}
446 
447 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
448 	if (rc < 0) {
449 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
450 			 pin_name(pin));
451 		kfree(entry);
452 		return rc;
453 	}
454 	dev->irq = rc;
455 	dev->irq_managed = 1;
456 
457 	if (link)
458 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
459 	else
460 		link_desc[0] = '\0';
461 
462 	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
463 		pin_name(pin), link_desc, gsi,
464 		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
465 		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
466 
467 	kfree(entry);
468 	return 0;
469 }
470 
471 void acpi_pci_irq_disable(struct pci_dev *dev)
472 {
473 	struct acpi_prt_entry *entry;
474 	int gsi;
475 	u8 pin;
476 
477 	pin = dev->pin;
478 	if (!pin || !dev->irq_managed || dev->irq <= 0)
479 		return;
480 
481 	/* Keep IOAPIC pin configuration when suspending */
482 	if (dev->dev.power.is_prepared)
483 		return;
484 #ifdef	CONFIG_PM
485 	if (dev->dev.power.runtime_status == RPM_SUSPENDING)
486 		return;
487 #endif
488 
489 	entry = acpi_pci_irq_lookup(dev, pin);
490 	if (!entry)
491 		return;
492 
493 	if (entry->link)
494 		gsi = acpi_pci_link_free_irq(entry->link);
495 	else
496 		gsi = entry->index;
497 
498 	kfree(entry);
499 
500 	/*
501 	 * TBD: It might be worth clearing dev->irq by magic constant
502 	 * (e.g. PCI_UNDEFINED_IRQ).
503 	 */
504 
505 	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
506 	if (gsi >= 0) {
507 		acpi_unregister_gsi(gsi);
508 		dev->irq_managed = 0;
509 	}
510 }
511