xref: /openbmc/linux/drivers/acpi/pci_irq.c (revision eb3fcf00)
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 (!prt->source)
135 			continue;
136 
137 		if (dmi_check_system(quirk->system) &&
138 		    entry->id.segment == quirk->segment &&
139 		    entry->id.bus == quirk->bus &&
140 		    entry->id.device == quirk->device &&
141 		    entry->pin == quirk->pin &&
142 		    !strcmp(prt->source, quirk->source) &&
143 		    strlen(prt->source) >= strlen(quirk->actual_source)) {
144 			printk(KERN_WARNING PREFIX "firmware reports "
145 				"%04x:%02x:%02x PCI INT %c connected to %s; "
146 				"changing to %s\n",
147 				entry->id.segment, entry->id.bus,
148 				entry->id.device, pin_name(entry->pin),
149 				prt->source, quirk->actual_source);
150 			strcpy(prt->source, quirk->actual_source);
151 		}
152 	}
153 }
154 
155 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
156 				  int pin, struct acpi_pci_routing_table *prt,
157 				  struct acpi_prt_entry **entry_ptr)
158 {
159 	int segment = pci_domain_nr(dev->bus);
160 	int bus = dev->bus->number;
161 	int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn);
162 	struct acpi_prt_entry *entry;
163 
164 	if (((prt->address >> 16) & 0xffff) != device ||
165 	    prt->pin + 1 != pin)
166 		return -ENODEV;
167 
168 	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
169 	if (!entry)
170 		return -ENOMEM;
171 
172 	/*
173 	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
174 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
175 	 * it here.
176 	 */
177 	entry->id.segment = segment;
178 	entry->id.bus = bus;
179 	entry->id.device = (prt->address >> 16) & 0xFFFF;
180 	entry->pin = prt->pin + 1;
181 
182 	do_prt_fixups(entry, prt);
183 
184 	entry->index = prt->source_index;
185 
186 	/*
187 	 * Type 1: Dynamic
188 	 * ---------------
189 	 * The 'source' field specifies the PCI interrupt link device used to
190 	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
191 	 * indicates which resource descriptor in the resource template (of
192 	 * the link device) this interrupt is allocated from.
193 	 *
194 	 * NOTE: Don't query the Link Device for IRQ information at this time
195 	 *       because Link Device enumeration may not have occurred yet
196 	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
197 	 *       namespace).
198 	 */
199 	if (prt->source[0])
200 		acpi_get_handle(handle, prt->source, &entry->link);
201 
202 	/*
203 	 * Type 2: Static
204 	 * --------------
205 	 * The 'source' field is NULL, and the 'source_index' field specifies
206 	 * the IRQ value, which is hardwired to specific interrupt inputs on
207 	 * the interrupt controller.
208 	 */
209 
210 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
211 			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
212 			      entry->id.segment, entry->id.bus,
213 			      entry->id.device, pin_name(entry->pin),
214 			      prt->source, entry->index));
215 
216 	*entry_ptr = entry;
217 
218 	return 0;
219 }
220 
221 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
222 			  int pin, struct acpi_prt_entry **entry_ptr)
223 {
224 	acpi_status status;
225 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
226 	struct acpi_pci_routing_table *entry;
227 	acpi_handle handle = NULL;
228 
229 	if (dev->bus->bridge)
230 		handle = ACPI_HANDLE(dev->bus->bridge);
231 
232 	if (!handle)
233 		return -ENODEV;
234 
235 	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
236 	status = acpi_get_irq_routing_table(handle, &buffer);
237 	if (ACPI_FAILURE(status)) {
238 		kfree(buffer.pointer);
239 		return -ENODEV;
240 	}
241 
242 	entry = buffer.pointer;
243 	while (entry && (entry->length > 0)) {
244 		if (!acpi_pci_irq_check_entry(handle, dev, pin,
245 						 entry, entry_ptr))
246 			break;
247 		entry = (struct acpi_pci_routing_table *)
248 		    ((unsigned long)entry + entry->length);
249 	}
250 
251 	kfree(buffer.pointer);
252 	return 0;
253 }
254 
255 /* --------------------------------------------------------------------------
256                           PCI Interrupt Routing Support
257    -------------------------------------------------------------------------- */
258 #ifdef CONFIG_X86_IO_APIC
259 extern int noioapicquirk;
260 extern int noioapicreroute;
261 
262 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
263 {
264 	struct pci_bus *bus_it;
265 
266 	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
267 		if (!bus_it->self)
268 			return 0;
269 		if (bus_it->self->irq_reroute_variant)
270 			return bus_it->self->irq_reroute_variant;
271 	}
272 	return 0;
273 }
274 
275 /*
276  * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
277  * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
278  * during interrupt handling). When this INTx generation cannot be disabled,
279  * we reroute these interrupts to their legacy equivalent to get rid of
280  * spurious interrupts.
281  */
282 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
283 				       struct acpi_prt_entry *entry)
284 {
285 	if (noioapicquirk || noioapicreroute) {
286 		return 0;
287 	} else {
288 		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
289 		case 0:
290 			/* no rerouting necessary */
291 			return 0;
292 		case INTEL_IRQ_REROUTE_VARIANT:
293 			/*
294 			 * Remap according to INTx routing table in 6700PXH
295 			 * specs, intel order number 302628-002, section
296 			 * 2.15.2. Other chipsets (80332, ...) have the same
297 			 * mapping and are handled here as well.
298 			 */
299 			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
300 				 "IRQ %d\n", entry->index,
301 				 (entry->index % 4) + 16);
302 			entry->index = (entry->index % 4) + 16;
303 			return 1;
304 		default:
305 			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
306 				 "IRQ: unknown mapping\n", entry->index);
307 			return -1;
308 		}
309 	}
310 }
311 #endif /* CONFIG_X86_IO_APIC */
312 
313 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
314 {
315 	struct acpi_prt_entry *entry = NULL;
316 	struct pci_dev *bridge;
317 	u8 bridge_pin, orig_pin = pin;
318 	int ret;
319 
320 	ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
321 	if (!ret && entry) {
322 #ifdef CONFIG_X86_IO_APIC
323 		acpi_reroute_boot_interrupt(dev, entry);
324 #endif /* CONFIG_X86_IO_APIC */
325 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
326 				  pci_name(dev), pin_name(pin)));
327 		return entry;
328 	}
329 
330 	/*
331 	 * Attempt to derive an IRQ for this device from a parent bridge's
332 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
333 	 */
334 	bridge = dev->bus->self;
335 	while (bridge) {
336 		pin = pci_swizzle_interrupt_pin(dev, pin);
337 
338 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
339 			/* PC card has the same IRQ as its cardbridge */
340 			bridge_pin = bridge->pin;
341 			if (!bridge_pin) {
342 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
343 						  "No interrupt pin configured for device %s\n",
344 						  pci_name(bridge)));
345 				return NULL;
346 			}
347 			pin = bridge_pin;
348 		}
349 
350 		ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
351 		if (!ret && entry) {
352 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
353 					 "Derived GSI for %s INT %c from %s\n",
354 					 pci_name(dev), pin_name(orig_pin),
355 					 pci_name(bridge)));
356 			return entry;
357 		}
358 
359 		dev = bridge;
360 		bridge = dev->bus->self;
361 	}
362 
363 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
364 		 pin_name(orig_pin));
365 	return NULL;
366 }
367 
368 #if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
369 static int acpi_isa_register_gsi(struct pci_dev *dev)
370 {
371 	u32 dev_gsi;
372 
373 	/* Interrupt Line values above 0xF are forbidden */
374 	if (dev->irq > 0 && (dev->irq <= 0xF) &&
375 	    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
376 		dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
377 			 pin_name(dev->pin), dev->irq);
378 		acpi_register_gsi(&dev->dev, dev_gsi,
379 				  ACPI_LEVEL_SENSITIVE,
380 				  ACPI_ACTIVE_LOW);
381 		return 0;
382 	}
383 	return -EINVAL;
384 }
385 #else
386 static inline int acpi_isa_register_gsi(struct pci_dev *dev)
387 {
388 	return -ENODEV;
389 }
390 #endif
391 
392 int acpi_pci_irq_enable(struct pci_dev *dev)
393 {
394 	struct acpi_prt_entry *entry;
395 	int gsi;
396 	u8 pin;
397 	int triggering = ACPI_LEVEL_SENSITIVE;
398 	int polarity = ACPI_ACTIVE_LOW;
399 	char *link = NULL;
400 	char link_desc[16];
401 	int rc;
402 
403 	pin = dev->pin;
404 	if (!pin) {
405 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
406 				  "No interrupt pin configured for device %s\n",
407 				  pci_name(dev)));
408 		return 0;
409 	}
410 
411 	if (pci_has_managed_irq(dev))
412 		return 0;
413 
414 	entry = acpi_pci_irq_lookup(dev, pin);
415 	if (!entry) {
416 		/*
417 		 * IDE legacy mode controller IRQs are magic. Why do compat
418 		 * extensions always make such a nasty mess.
419 		 */
420 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
421 				(dev->class & 0x05) == 0)
422 			return 0;
423 	}
424 
425 	if (entry) {
426 		if (entry->link)
427 			gsi = acpi_pci_link_allocate_irq(entry->link,
428 							 entry->index,
429 							 &triggering, &polarity,
430 							 &link);
431 		else
432 			gsi = entry->index;
433 	} else
434 		gsi = -1;
435 
436 	/*
437 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
438 	 * driver reported one, then use it. Exit in any case.
439 	 */
440 	if (gsi < 0) {
441 		if (acpi_isa_register_gsi(dev))
442 			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
443 				 pin_name(pin));
444 
445 		kfree(entry);
446 		return 0;
447 	}
448 
449 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
450 	if (rc < 0) {
451 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
452 			 pin_name(pin));
453 		kfree(entry);
454 		return rc;
455 	}
456 	pci_set_managed_irq(dev, rc);
457 
458 	if (link)
459 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
460 	else
461 		link_desc[0] = '\0';
462 
463 	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
464 		pin_name(pin), link_desc, gsi,
465 		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
466 		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
467 
468 	kfree(entry);
469 	return 0;
470 }
471 
472 void acpi_pci_irq_disable(struct pci_dev *dev)
473 {
474 	struct acpi_prt_entry *entry;
475 	int gsi;
476 	u8 pin;
477 
478 	pin = dev->pin;
479 	if (!pin || !pci_has_managed_irq(dev))
480 		return;
481 
482 	entry = acpi_pci_irq_lookup(dev, pin);
483 	if (!entry)
484 		return;
485 
486 	if (entry->link)
487 		gsi = acpi_pci_link_free_irq(entry->link);
488 	else
489 		gsi = entry->index;
490 
491 	kfree(entry);
492 
493 	/*
494 	 * TBD: It might be worth clearing dev->irq by magic constant
495 	 * (e.g. PCI_UNDEFINED_IRQ).
496 	 */
497 
498 	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
499 	if (gsi >= 0) {
500 		acpi_unregister_gsi(gsi);
501 		pci_reset_managed_irq(dev);
502 	}
503 }
504