xref: /openbmc/linux/drivers/acpi/pci_irq.c (revision c0e297dc)
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 
41 #define PREFIX "ACPI: "
42 
43 #define _COMPONENT		ACPI_PCI_COMPONENT
44 ACPI_MODULE_NAME("pci_irq");
45 
46 struct acpi_prt_entry {
47 	struct acpi_pci_id	id;
48 	u8			pin;
49 	acpi_handle		link;
50 	u32			index;		/* GSI, or link _CRS index */
51 };
52 
53 static inline char pin_name(int pin)
54 {
55 	return 'A' + pin - 1;
56 }
57 
58 /* --------------------------------------------------------------------------
59                          PCI IRQ Routing Table (PRT) Support
60    -------------------------------------------------------------------------- */
61 
62 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
63 static const struct dmi_system_id medion_md9580[] = {
64 	{
65 		.ident = "Medion MD9580-F laptop",
66 		.matches = {
67 			DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
68 			DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
69 		},
70 	},
71 	{ }
72 };
73 
74 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
75 static const struct dmi_system_id dell_optiplex[] = {
76 	{
77 		.ident = "Dell Optiplex GX1",
78 		.matches = {
79 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
80 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
81 		},
82 	},
83 	{ }
84 };
85 
86 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
87 static const struct dmi_system_id hp_t5710[] = {
88 	{
89 		.ident = "HP t5710",
90 		.matches = {
91 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
92 			DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
93 			DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
94 		},
95 	},
96 	{ }
97 };
98 
99 struct prt_quirk {
100 	const struct dmi_system_id *system;
101 	unsigned int		segment;
102 	unsigned int		bus;
103 	unsigned int		device;
104 	unsigned char		pin;
105 	const char		*source;	/* according to BIOS */
106 	const char		*actual_source;
107 };
108 
109 #define PCI_INTX_PIN(c)		(c - 'A' + 1)
110 
111 /*
112  * These systems have incorrect _PRT entries.  The BIOS claims the PCI
113  * interrupt at the listed segment/bus/device/pin is connected to the first
114  * link device, but it is actually connected to the second.
115  */
116 static const struct prt_quirk prt_quirks[] = {
117 	{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
118 		"\\_SB_.PCI0.ISA_.LNKA",
119 		"\\_SB_.PCI0.ISA_.LNKB"},
120 	{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
121 		"\\_SB_.LNKB",
122 		"\\_SB_.LNKA"},
123 	{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
124 		"\\_SB_.PCI0.LNK1",
125 		"\\_SB_.PCI0.LNK3"},
126 };
127 
128 static void do_prt_fixups(struct acpi_prt_entry *entry,
129 			  struct acpi_pci_routing_table *prt)
130 {
131 	int i;
132 	const struct prt_quirk *quirk;
133 
134 	for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
135 		quirk = &prt_quirks[i];
136 
137 		/* All current quirks involve link devices, not GSIs */
138 		if (!prt->source)
139 			continue;
140 
141 		if (dmi_check_system(quirk->system) &&
142 		    entry->id.segment == quirk->segment &&
143 		    entry->id.bus == quirk->bus &&
144 		    entry->id.device == quirk->device &&
145 		    entry->pin == quirk->pin &&
146 		    !strcmp(prt->source, quirk->source) &&
147 		    strlen(prt->source) >= strlen(quirk->actual_source)) {
148 			printk(KERN_WARNING PREFIX "firmware reports "
149 				"%04x:%02x:%02x PCI INT %c connected to %s; "
150 				"changing to %s\n",
151 				entry->id.segment, entry->id.bus,
152 				entry->id.device, pin_name(entry->pin),
153 				prt->source, quirk->actual_source);
154 			strcpy(prt->source, quirk->actual_source);
155 		}
156 	}
157 }
158 
159 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
160 				  int pin, struct acpi_pci_routing_table *prt,
161 				  struct acpi_prt_entry **entry_ptr)
162 {
163 	int segment = pci_domain_nr(dev->bus);
164 	int bus = dev->bus->number;
165 	int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn);
166 	struct acpi_prt_entry *entry;
167 
168 	if (((prt->address >> 16) & 0xffff) != device ||
169 	    prt->pin + 1 != pin)
170 		return -ENODEV;
171 
172 	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
173 	if (!entry)
174 		return -ENOMEM;
175 
176 	/*
177 	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
178 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
179 	 * it here.
180 	 */
181 	entry->id.segment = segment;
182 	entry->id.bus = bus;
183 	entry->id.device = (prt->address >> 16) & 0xFFFF;
184 	entry->pin = prt->pin + 1;
185 
186 	do_prt_fixups(entry, prt);
187 
188 	entry->index = prt->source_index;
189 
190 	/*
191 	 * Type 1: Dynamic
192 	 * ---------------
193 	 * The 'source' field specifies the PCI interrupt link device used to
194 	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
195 	 * indicates which resource descriptor in the resource template (of
196 	 * the link device) this interrupt is allocated from.
197 	 *
198 	 * NOTE: Don't query the Link Device for IRQ information at this time
199 	 *       because Link Device enumeration may not have occurred yet
200 	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
201 	 *       namespace).
202 	 */
203 	if (prt->source[0])
204 		acpi_get_handle(handle, prt->source, &entry->link);
205 
206 	/*
207 	 * Type 2: Static
208 	 * --------------
209 	 * The 'source' field is NULL, and the 'source_index' field specifies
210 	 * the IRQ value, which is hardwired to specific interrupt inputs on
211 	 * the interrupt controller.
212 	 */
213 
214 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
215 			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
216 			      entry->id.segment, entry->id.bus,
217 			      entry->id.device, pin_name(entry->pin),
218 			      prt->source, entry->index));
219 
220 	*entry_ptr = entry;
221 
222 	return 0;
223 }
224 
225 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
226 			  int pin, struct acpi_prt_entry **entry_ptr)
227 {
228 	acpi_status status;
229 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
230 	struct acpi_pci_routing_table *entry;
231 	acpi_handle handle = NULL;
232 
233 	if (dev->bus->bridge)
234 		handle = ACPI_HANDLE(dev->bus->bridge);
235 
236 	if (!handle)
237 		return -ENODEV;
238 
239 	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
240 	status = acpi_get_irq_routing_table(handle, &buffer);
241 	if (ACPI_FAILURE(status)) {
242 		kfree(buffer.pointer);
243 		return -ENODEV;
244 	}
245 
246 	entry = buffer.pointer;
247 	while (entry && (entry->length > 0)) {
248 		if (!acpi_pci_irq_check_entry(handle, dev, pin,
249 						 entry, entry_ptr))
250 			break;
251 		entry = (struct acpi_pci_routing_table *)
252 		    ((unsigned long)entry + entry->length);
253 	}
254 
255 	kfree(buffer.pointer);
256 	return 0;
257 }
258 
259 /* --------------------------------------------------------------------------
260                           PCI Interrupt Routing Support
261    -------------------------------------------------------------------------- */
262 #ifdef CONFIG_X86_IO_APIC
263 extern int noioapicquirk;
264 extern int noioapicreroute;
265 
266 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
267 {
268 	struct pci_bus *bus_it;
269 
270 	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
271 		if (!bus_it->self)
272 			return 0;
273 		if (bus_it->self->irq_reroute_variant)
274 			return bus_it->self->irq_reroute_variant;
275 	}
276 	return 0;
277 }
278 
279 /*
280  * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
281  * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
282  * during interrupt handling). When this INTx generation cannot be disabled,
283  * we reroute these interrupts to their legacy equivalent to get rid of
284  * spurious interrupts.
285  */
286 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
287 				       struct acpi_prt_entry *entry)
288 {
289 	if (noioapicquirk || noioapicreroute) {
290 		return 0;
291 	} else {
292 		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
293 		case 0:
294 			/* no rerouting necessary */
295 			return 0;
296 		case INTEL_IRQ_REROUTE_VARIANT:
297 			/*
298 			 * Remap according to INTx routing table in 6700PXH
299 			 * specs, intel order number 302628-002, section
300 			 * 2.15.2. Other chipsets (80332, ...) have the same
301 			 * mapping and are handled here as well.
302 			 */
303 			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
304 				 "IRQ %d\n", entry->index,
305 				 (entry->index % 4) + 16);
306 			entry->index = (entry->index % 4) + 16;
307 			return 1;
308 		default:
309 			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
310 				 "IRQ: unknown mapping\n", entry->index);
311 			return -1;
312 		}
313 	}
314 }
315 #endif /* CONFIG_X86_IO_APIC */
316 
317 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
318 {
319 	struct acpi_prt_entry *entry = NULL;
320 	struct pci_dev *bridge;
321 	u8 bridge_pin, orig_pin = pin;
322 	int ret;
323 
324 	ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
325 	if (!ret && entry) {
326 #ifdef CONFIG_X86_IO_APIC
327 		acpi_reroute_boot_interrupt(dev, entry);
328 #endif /* CONFIG_X86_IO_APIC */
329 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
330 				  pci_name(dev), pin_name(pin)));
331 		return entry;
332 	}
333 
334 	/*
335 	 * Attempt to derive an IRQ for this device from a parent bridge's
336 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
337 	 */
338 	bridge = dev->bus->self;
339 	while (bridge) {
340 		pin = pci_swizzle_interrupt_pin(dev, pin);
341 
342 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
343 			/* PC card has the same IRQ as its cardbridge */
344 			bridge_pin = bridge->pin;
345 			if (!bridge_pin) {
346 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
347 						  "No interrupt pin configured for device %s\n",
348 						  pci_name(bridge)));
349 				return NULL;
350 			}
351 			pin = bridge_pin;
352 		}
353 
354 		ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
355 		if (!ret && entry) {
356 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
357 					 "Derived GSI for %s INT %c from %s\n",
358 					 pci_name(dev), pin_name(orig_pin),
359 					 pci_name(bridge)));
360 			return entry;
361 		}
362 
363 		dev = bridge;
364 		bridge = dev->bus->self;
365 	}
366 
367 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
368 		 pin_name(orig_pin));
369 	return NULL;
370 }
371 
372 #if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
373 static int acpi_isa_register_gsi(struct pci_dev *dev)
374 {
375 	u32 dev_gsi;
376 
377 	/* Interrupt Line values above 0xF are forbidden */
378 	if (dev->irq > 0 && (dev->irq <= 0xF) &&
379 	    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
380 		dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
381 			 pin_name(dev->pin), dev->irq);
382 		acpi_register_gsi(&dev->dev, dev_gsi,
383 				  ACPI_LEVEL_SENSITIVE,
384 				  ACPI_ACTIVE_LOW);
385 		return 0;
386 	}
387 	return -EINVAL;
388 }
389 #else
390 static inline int acpi_isa_register_gsi(struct pci_dev *dev)
391 {
392 	return -ENODEV;
393 }
394 #endif
395 
396 int acpi_pci_irq_enable(struct pci_dev *dev)
397 {
398 	struct acpi_prt_entry *entry;
399 	int gsi;
400 	u8 pin;
401 	int triggering = ACPI_LEVEL_SENSITIVE;
402 	int polarity = ACPI_ACTIVE_LOW;
403 	char *link = NULL;
404 	char link_desc[16];
405 	int rc;
406 
407 	pin = dev->pin;
408 	if (!pin) {
409 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
410 				  "No interrupt pin configured for device %s\n",
411 				  pci_name(dev)));
412 		return 0;
413 	}
414 
415 	if (dev->irq_managed && dev->irq > 0)
416 		return 0;
417 
418 	entry = acpi_pci_irq_lookup(dev, pin);
419 	if (!entry) {
420 		/*
421 		 * IDE legacy mode controller IRQs are magic. Why do compat
422 		 * extensions always make such a nasty mess.
423 		 */
424 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
425 				(dev->class & 0x05) == 0)
426 			return 0;
427 	}
428 
429 	if (entry) {
430 		if (entry->link)
431 			gsi = acpi_pci_link_allocate_irq(entry->link,
432 							 entry->index,
433 							 &triggering, &polarity,
434 							 &link);
435 		else
436 			gsi = entry->index;
437 	} else
438 		gsi = -1;
439 
440 	/*
441 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
442 	 * driver reported one, then use it. Exit in any case.
443 	 */
444 	if (gsi < 0) {
445 		if (acpi_isa_register_gsi(dev))
446 			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
447 				 pin_name(pin));
448 
449 		kfree(entry);
450 		return 0;
451 	}
452 
453 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
454 	if (rc < 0) {
455 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
456 			 pin_name(pin));
457 		kfree(entry);
458 		return rc;
459 	}
460 	dev->irq = rc;
461 	dev->irq_managed = 1;
462 
463 	if (link)
464 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
465 	else
466 		link_desc[0] = '\0';
467 
468 	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
469 		pin_name(pin), link_desc, gsi,
470 		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
471 		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
472 
473 	kfree(entry);
474 	return 0;
475 }
476 
477 void acpi_pci_irq_disable(struct pci_dev *dev)
478 {
479 	struct acpi_prt_entry *entry;
480 	int gsi;
481 	u8 pin;
482 
483 	pin = dev->pin;
484 	if (!pin || !dev->irq_managed || dev->irq <= 0)
485 		return;
486 
487 	/* Keep IOAPIC pin configuration when suspending */
488 	if (dev->dev.power.is_prepared)
489 		return;
490 #ifdef	CONFIG_PM
491 	if (dev->dev.power.runtime_status == RPM_SUSPENDING)
492 		return;
493 #endif
494 
495 	entry = acpi_pci_irq_lookup(dev, pin);
496 	if (!entry)
497 		return;
498 
499 	if (entry->link)
500 		gsi = acpi_pci_link_free_irq(entry->link);
501 	else
502 		gsi = entry->index;
503 
504 	kfree(entry);
505 
506 	/*
507 	 * TBD: It might be worth clearing dev->irq by magic constant
508 	 * (e.g. PCI_UNDEFINED_IRQ).
509 	 */
510 
511 	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
512 	if (gsi >= 0) {
513 		acpi_unregister_gsi(gsi);
514 		dev->irq_managed = 0;
515 	}
516 }
517