xref: /openbmc/linux/drivers/acpi/pci_irq.c (revision afb46f79)
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 list_head	list;
48 	struct acpi_pci_id	id;
49 	u8			pin;
50 	acpi_handle		link;
51 	u32			index;		/* GSI, or link _CRS index */
52 };
53 
54 static inline char pin_name(int pin)
55 {
56 	return 'A' + pin - 1;
57 }
58 
59 /* --------------------------------------------------------------------------
60                          PCI IRQ Routing Table (PRT) Support
61    -------------------------------------------------------------------------- */
62 
63 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
64 static const struct dmi_system_id medion_md9580[] = {
65 	{
66 		.ident = "Medion MD9580-F laptop",
67 		.matches = {
68 			DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
69 			DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
70 		},
71 	},
72 	{ }
73 };
74 
75 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
76 static const struct dmi_system_id dell_optiplex[] = {
77 	{
78 		.ident = "Dell Optiplex GX1",
79 		.matches = {
80 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
81 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
82 		},
83 	},
84 	{ }
85 };
86 
87 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
88 static const struct dmi_system_id hp_t5710[] = {
89 	{
90 		.ident = "HP t5710",
91 		.matches = {
92 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
93 			DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
94 			DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
95 		},
96 	},
97 	{ }
98 };
99 
100 struct prt_quirk {
101 	const struct dmi_system_id *system;
102 	unsigned int		segment;
103 	unsigned int		bus;
104 	unsigned int		device;
105 	unsigned char		pin;
106 	const char		*source;	/* according to BIOS */
107 	const char		*actual_source;
108 };
109 
110 #define PCI_INTX_PIN(c)		(c - 'A' + 1)
111 
112 /*
113  * These systems have incorrect _PRT entries.  The BIOS claims the PCI
114  * interrupt at the listed segment/bus/device/pin is connected to the first
115  * link device, but it is actually connected to the second.
116  */
117 static const struct prt_quirk prt_quirks[] = {
118 	{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
119 		"\\_SB_.PCI0.ISA_.LNKA",
120 		"\\_SB_.PCI0.ISA_.LNKB"},
121 	{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
122 		"\\_SB_.LNKB",
123 		"\\_SB_.LNKA"},
124 	{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
125 		"\\_SB_.PCI0.LNK1",
126 		"\\_SB_.PCI0.LNK3"},
127 };
128 
129 static void do_prt_fixups(struct acpi_prt_entry *entry,
130 			  struct acpi_pci_routing_table *prt)
131 {
132 	int i;
133 	const struct prt_quirk *quirk;
134 
135 	for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
136 		quirk = &prt_quirks[i];
137 
138 		/* All current quirks involve link devices, not GSIs */
139 		if (!prt->source)
140 			continue;
141 
142 		if (dmi_check_system(quirk->system) &&
143 		    entry->id.segment == quirk->segment &&
144 		    entry->id.bus == quirk->bus &&
145 		    entry->id.device == quirk->device &&
146 		    entry->pin == quirk->pin &&
147 		    !strcmp(prt->source, quirk->source) &&
148 		    strlen(prt->source) >= strlen(quirk->actual_source)) {
149 			printk(KERN_WARNING PREFIX "firmware reports "
150 				"%04x:%02x:%02x PCI INT %c connected to %s; "
151 				"changing to %s\n",
152 				entry->id.segment, entry->id.bus,
153 				entry->id.device, pin_name(entry->pin),
154 				prt->source, quirk->actual_source);
155 			strcpy(prt->source, quirk->actual_source);
156 		}
157 	}
158 }
159 
160 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
161 				  int pin, struct acpi_pci_routing_table *prt,
162 				  struct acpi_prt_entry **entry_ptr)
163 {
164 	int segment = pci_domain_nr(dev->bus);
165 	int bus = dev->bus->number;
166 	int device = PCI_SLOT(dev->devfn);
167 	struct acpi_prt_entry *entry;
168 
169 	if (((prt->address >> 16) & 0xffff) != device ||
170 	    prt->pin + 1 != pin)
171 		return -ENODEV;
172 
173 	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
174 	if (!entry)
175 		return -ENOMEM;
176 
177 	/*
178 	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
179 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
180 	 * it here.
181 	 */
182 	entry->id.segment = segment;
183 	entry->id.bus = bus;
184 	entry->id.device = (prt->address >> 16) & 0xFFFF;
185 	entry->pin = prt->pin + 1;
186 
187 	do_prt_fixups(entry, prt);
188 
189 	entry->index = prt->source_index;
190 
191 	/*
192 	 * Type 1: Dynamic
193 	 * ---------------
194 	 * The 'source' field specifies the PCI interrupt link device used to
195 	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
196 	 * indicates which resource descriptor in the resource template (of
197 	 * the link device) this interrupt is allocated from.
198 	 *
199 	 * NOTE: Don't query the Link Device for IRQ information at this time
200 	 *       because Link Device enumeration may not have occurred yet
201 	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
202 	 *       namespace).
203 	 */
204 	if (prt->source[0])
205 		acpi_get_handle(handle, prt->source, &entry->link);
206 
207 	/*
208 	 * Type 2: Static
209 	 * --------------
210 	 * The 'source' field is NULL, and the 'source_index' field specifies
211 	 * the IRQ value, which is hardwired to specific interrupt inputs on
212 	 * the interrupt controller.
213 	 */
214 
215 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
216 			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
217 			      entry->id.segment, entry->id.bus,
218 			      entry->id.device, pin_name(entry->pin),
219 			      prt->source, entry->index));
220 
221 	*entry_ptr = entry;
222 
223 	return 0;
224 }
225 
226 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
227 			  int pin, struct acpi_prt_entry **entry_ptr)
228 {
229 	acpi_status status;
230 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
231 	struct acpi_pci_routing_table *entry;
232 	acpi_handle handle = NULL;
233 
234 	if (dev->bus->bridge)
235 		handle = ACPI_HANDLE(dev->bus->bridge);
236 
237 	if (!handle)
238 		return -ENODEV;
239 
240 	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
241 	status = acpi_get_irq_routing_table(handle, &buffer);
242 	if (ACPI_FAILURE(status)) {
243 		kfree(buffer.pointer);
244 		return -ENODEV;
245 	}
246 
247 	entry = buffer.pointer;
248 	while (entry && (entry->length > 0)) {
249 		if (!acpi_pci_irq_check_entry(handle, dev, pin,
250 						 entry, entry_ptr))
251 			break;
252 		entry = (struct acpi_pci_routing_table *)
253 		    ((unsigned long)entry + entry->length);
254 	}
255 
256 	kfree(buffer.pointer);
257 	return 0;
258 }
259 
260 /* --------------------------------------------------------------------------
261                           PCI Interrupt Routing Support
262    -------------------------------------------------------------------------- */
263 #ifdef CONFIG_X86_IO_APIC
264 extern int noioapicquirk;
265 extern int noioapicreroute;
266 
267 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
268 {
269 	struct pci_bus *bus_it;
270 
271 	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
272 		if (!bus_it->self)
273 			return 0;
274 		if (bus_it->self->irq_reroute_variant)
275 			return bus_it->self->irq_reroute_variant;
276 	}
277 	return 0;
278 }
279 
280 /*
281  * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
282  * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
283  * during interrupt handling). When this INTx generation cannot be disabled,
284  * we reroute these interrupts to their legacy equivalent to get rid of
285  * spurious interrupts.
286  */
287 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
288 				       struct acpi_prt_entry *entry)
289 {
290 	if (noioapicquirk || noioapicreroute) {
291 		return 0;
292 	} else {
293 		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
294 		case 0:
295 			/* no rerouting necessary */
296 			return 0;
297 		case INTEL_IRQ_REROUTE_VARIANT:
298 			/*
299 			 * Remap according to INTx routing table in 6700PXH
300 			 * specs, intel order number 302628-002, section
301 			 * 2.15.2. Other chipsets (80332, ...) have the same
302 			 * mapping and are handled here as well.
303 			 */
304 			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
305 				 "IRQ %d\n", entry->index,
306 				 (entry->index % 4) + 16);
307 			entry->index = (entry->index % 4) + 16;
308 			return 1;
309 		default:
310 			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
311 				 "IRQ: unknown mapping\n", entry->index);
312 			return -1;
313 		}
314 	}
315 }
316 #endif /* CONFIG_X86_IO_APIC */
317 
318 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
319 {
320 	struct acpi_prt_entry *entry = NULL;
321 	struct pci_dev *bridge;
322 	u8 bridge_pin, orig_pin = pin;
323 	int ret;
324 
325 	ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
326 	if (!ret && entry) {
327 #ifdef CONFIG_X86_IO_APIC
328 		acpi_reroute_boot_interrupt(dev, entry);
329 #endif /* CONFIG_X86_IO_APIC */
330 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
331 				  pci_name(dev), pin_name(pin)));
332 		return entry;
333 	}
334 
335 	/*
336 	 * Attempt to derive an IRQ for this device from a parent bridge's
337 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
338 	 */
339 	bridge = dev->bus->self;
340 	while (bridge) {
341 		pin = pci_swizzle_interrupt_pin(dev, pin);
342 
343 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
344 			/* PC card has the same IRQ as its cardbridge */
345 			bridge_pin = bridge->pin;
346 			if (!bridge_pin) {
347 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
348 						  "No interrupt pin configured for device %s\n",
349 						  pci_name(bridge)));
350 				return NULL;
351 			}
352 			pin = bridge_pin;
353 		}
354 
355 		ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
356 		if (!ret && entry) {
357 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
358 					 "Derived GSI for %s INT %c from %s\n",
359 					 pci_name(dev), pin_name(orig_pin),
360 					 pci_name(bridge)));
361 			return entry;
362 		}
363 
364 		dev = bridge;
365 		bridge = dev->bus->self;
366 	}
367 
368 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
369 		 pin_name(orig_pin));
370 	return NULL;
371 }
372 
373 #if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
374 static int acpi_isa_register_gsi(struct pci_dev *dev)
375 {
376 	u32 dev_gsi;
377 
378 	/* Interrupt Line values above 0xF are forbidden */
379 	if (dev->irq > 0 && (dev->irq <= 0xF) &&
380 	    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
381 		dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
382 			 pin_name(dev->pin), dev->irq);
383 		acpi_register_gsi(&dev->dev, dev_gsi,
384 				  ACPI_LEVEL_SENSITIVE,
385 				  ACPI_ACTIVE_LOW);
386 		return 0;
387 	}
388 	return -EINVAL;
389 }
390 #else
391 static inline int acpi_isa_register_gsi(struct pci_dev *dev)
392 {
393 	return -ENODEV;
394 }
395 #endif
396 
397 int acpi_pci_irq_enable(struct pci_dev *dev)
398 {
399 	struct acpi_prt_entry *entry;
400 	int gsi;
401 	u8 pin;
402 	int triggering = ACPI_LEVEL_SENSITIVE;
403 	int polarity = ACPI_ACTIVE_LOW;
404 	char *link = NULL;
405 	char link_desc[16];
406 	int rc;
407 
408 	pin = dev->pin;
409 	if (!pin) {
410 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
411 				  "No interrupt pin configured for device %s\n",
412 				  pci_name(dev)));
413 		return 0;
414 	}
415 
416 	entry = acpi_pci_irq_lookup(dev, pin);
417 	if (!entry) {
418 		/*
419 		 * IDE legacy mode controller IRQs are magic. Why do compat
420 		 * extensions always make such a nasty mess.
421 		 */
422 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
423 				(dev->class & 0x05) == 0)
424 			return 0;
425 	}
426 
427 	if (entry) {
428 		if (entry->link)
429 			gsi = acpi_pci_link_allocate_irq(entry->link,
430 							 entry->index,
431 							 &triggering, &polarity,
432 							 &link);
433 		else
434 			gsi = entry->index;
435 	} else
436 		gsi = -1;
437 
438 	/*
439 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
440 	 * driver reported one, then use it. Exit in any case.
441 	 */
442 	if (gsi < 0) {
443 		if (acpi_isa_register_gsi(dev))
444 			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
445 				 pin_name(pin));
446 
447 		kfree(entry);
448 		return 0;
449 	}
450 
451 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
452 	if (rc < 0) {
453 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
454 			 pin_name(pin));
455 		kfree(entry);
456 		return rc;
457 	}
458 	dev->irq = rc;
459 
460 	if (link)
461 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
462 	else
463 		link_desc[0] = '\0';
464 
465 	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
466 		pin_name(pin), link_desc, gsi,
467 		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
468 		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
469 
470 	kfree(entry);
471 	return 0;
472 }
473 
474 void acpi_pci_irq_disable(struct pci_dev *dev)
475 {
476 	struct acpi_prt_entry *entry;
477 	int gsi;
478 	u8 pin;
479 
480 	pin = dev->pin;
481 	if (!pin)
482 		return;
483 
484 	entry = acpi_pci_irq_lookup(dev, pin);
485 	if (!entry)
486 		return;
487 
488 	if (entry->link)
489 		gsi = acpi_pci_link_free_irq(entry->link);
490 	else
491 		gsi = entry->index;
492 
493 	kfree(entry);
494 
495 	/*
496 	 * TBD: It might be worth clearing dev->irq by magic constant
497 	 * (e.g. PCI_UNDEFINED_IRQ).
498 	 */
499 
500 	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
501 	acpi_unregister_gsi(gsi);
502 }
503