xref: /openbmc/linux/drivers/acpi/pci_irq.c (revision 12eb4683)
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 inline char pin_name(int pin)
57 {
58 	return 'A' + pin - 1;
59 }
60 
61 /* --------------------------------------------------------------------------
62                          PCI IRQ Routing Table (PRT) Support
63    -------------------------------------------------------------------------- */
64 
65 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
66 static const struct dmi_system_id medion_md9580[] = {
67 	{
68 		.ident = "Medion MD9580-F laptop",
69 		.matches = {
70 			DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
71 			DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
72 		},
73 	},
74 	{ }
75 };
76 
77 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
78 static const struct dmi_system_id dell_optiplex[] = {
79 	{
80 		.ident = "Dell Optiplex GX1",
81 		.matches = {
82 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
83 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
84 		},
85 	},
86 	{ }
87 };
88 
89 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
90 static const struct dmi_system_id hp_t5710[] = {
91 	{
92 		.ident = "HP t5710",
93 		.matches = {
94 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
95 			DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
96 			DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
97 		},
98 	},
99 	{ }
100 };
101 
102 struct prt_quirk {
103 	const struct dmi_system_id *system;
104 	unsigned int		segment;
105 	unsigned int		bus;
106 	unsigned int		device;
107 	unsigned char		pin;
108 	const char		*source;	/* according to BIOS */
109 	const char		*actual_source;
110 };
111 
112 #define PCI_INTX_PIN(c)		(c - 'A' + 1)
113 
114 /*
115  * These systems have incorrect _PRT entries.  The BIOS claims the PCI
116  * interrupt at the listed segment/bus/device/pin is connected to the first
117  * link device, but it is actually connected to the second.
118  */
119 static const struct prt_quirk prt_quirks[] = {
120 	{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
121 		"\\_SB_.PCI0.ISA_.LNKA",
122 		"\\_SB_.PCI0.ISA_.LNKB"},
123 	{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
124 		"\\_SB_.LNKB",
125 		"\\_SB_.LNKA"},
126 	{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
127 		"\\_SB_.PCI0.LNK1",
128 		"\\_SB_.PCI0.LNK3"},
129 };
130 
131 static void do_prt_fixups(struct acpi_prt_entry *entry,
132 			  struct acpi_pci_routing_table *prt)
133 {
134 	int i;
135 	const struct prt_quirk *quirk;
136 
137 	for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
138 		quirk = &prt_quirks[i];
139 
140 		/* All current quirks involve link devices, not GSIs */
141 		if (!prt->source)
142 			continue;
143 
144 		if (dmi_check_system(quirk->system) &&
145 		    entry->id.segment == quirk->segment &&
146 		    entry->id.bus == quirk->bus &&
147 		    entry->id.device == quirk->device &&
148 		    entry->pin == quirk->pin &&
149 		    !strcmp(prt->source, quirk->source) &&
150 		    strlen(prt->source) >= strlen(quirk->actual_source)) {
151 			printk(KERN_WARNING PREFIX "firmware reports "
152 				"%04x:%02x:%02x PCI INT %c connected to %s; "
153 				"changing to %s\n",
154 				entry->id.segment, entry->id.bus,
155 				entry->id.device, pin_name(entry->pin),
156 				prt->source, quirk->actual_source);
157 			strcpy(prt->source, quirk->actual_source);
158 		}
159 	}
160 }
161 
162 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
163 				  int pin, struct acpi_pci_routing_table *prt,
164 				  struct acpi_prt_entry **entry_ptr)
165 {
166 	int segment = pci_domain_nr(dev->bus);
167 	int bus = dev->bus->number;
168 	int device = PCI_SLOT(dev->devfn);
169 	struct acpi_prt_entry *entry;
170 
171 	if (((prt->address >> 16) & 0xffff) != device ||
172 	    prt->pin + 1 != pin)
173 		return -ENODEV;
174 
175 	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
176 	if (!entry)
177 		return -ENOMEM;
178 
179 	/*
180 	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
181 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
182 	 * it here.
183 	 */
184 	entry->id.segment = segment;
185 	entry->id.bus = bus;
186 	entry->id.device = (prt->address >> 16) & 0xFFFF;
187 	entry->pin = prt->pin + 1;
188 
189 	do_prt_fixups(entry, prt);
190 
191 	entry->index = prt->source_index;
192 
193 	/*
194 	 * Type 1: Dynamic
195 	 * ---------------
196 	 * The 'source' field specifies the PCI interrupt link device used to
197 	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
198 	 * indicates which resource descriptor in the resource template (of
199 	 * the link device) this interrupt is allocated from.
200 	 *
201 	 * NOTE: Don't query the Link Device for IRQ information at this time
202 	 *       because Link Device enumeration may not have occurred yet
203 	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
204 	 *       namespace).
205 	 */
206 	if (prt->source[0])
207 		acpi_get_handle(handle, prt->source, &entry->link);
208 
209 	/*
210 	 * Type 2: Static
211 	 * --------------
212 	 * The 'source' field is NULL, and the 'source_index' field specifies
213 	 * the IRQ value, which is hardwired to specific interrupt inputs on
214 	 * the interrupt controller.
215 	 */
216 
217 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
218 			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
219 			      entry->id.segment, entry->id.bus,
220 			      entry->id.device, pin_name(entry->pin),
221 			      prt->source, entry->index));
222 
223 	*entry_ptr = entry;
224 
225 	return 0;
226 }
227 
228 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
229 			  int pin, struct acpi_prt_entry **entry_ptr)
230 {
231 	acpi_status status;
232 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
233 	struct acpi_pci_routing_table *entry;
234 	acpi_handle handle = NULL;
235 
236 	if (dev->bus->bridge)
237 		handle = ACPI_HANDLE(dev->bus->bridge);
238 
239 	if (!handle)
240 		return -ENODEV;
241 
242 	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
243 	status = acpi_get_irq_routing_table(handle, &buffer);
244 	if (ACPI_FAILURE(status)) {
245 		kfree(buffer.pointer);
246 		return -ENODEV;
247 	}
248 
249 	entry = buffer.pointer;
250 	while (entry && (entry->length > 0)) {
251 		if (!acpi_pci_irq_check_entry(handle, dev, pin,
252 						 entry, entry_ptr))
253 			break;
254 		entry = (struct acpi_pci_routing_table *)
255 		    ((unsigned long)entry + entry->length);
256 	}
257 
258 	kfree(buffer.pointer);
259 	return 0;
260 }
261 
262 /* --------------------------------------------------------------------------
263                           PCI Interrupt Routing Support
264    -------------------------------------------------------------------------- */
265 #ifdef CONFIG_X86_IO_APIC
266 extern int noioapicquirk;
267 extern int noioapicreroute;
268 
269 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
270 {
271 	struct pci_bus *bus_it;
272 
273 	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
274 		if (!bus_it->self)
275 			return 0;
276 		if (bus_it->self->irq_reroute_variant)
277 			return bus_it->self->irq_reroute_variant;
278 	}
279 	return 0;
280 }
281 
282 /*
283  * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
284  * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
285  * during interrupt handling). When this INTx generation cannot be disabled,
286  * we reroute these interrupts to their legacy equivalent to get rid of
287  * spurious interrupts.
288  */
289 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
290 				       struct acpi_prt_entry *entry)
291 {
292 	if (noioapicquirk || noioapicreroute) {
293 		return 0;
294 	} else {
295 		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
296 		case 0:
297 			/* no rerouting necessary */
298 			return 0;
299 		case INTEL_IRQ_REROUTE_VARIANT:
300 			/*
301 			 * Remap according to INTx routing table in 6700PXH
302 			 * specs, intel order number 302628-002, section
303 			 * 2.15.2. Other chipsets (80332, ...) have the same
304 			 * mapping and are handled here as well.
305 			 */
306 			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
307 				 "IRQ %d\n", entry->index,
308 				 (entry->index % 4) + 16);
309 			entry->index = (entry->index % 4) + 16;
310 			return 1;
311 		default:
312 			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
313 				 "IRQ: unknown mapping\n", entry->index);
314 			return -1;
315 		}
316 	}
317 }
318 #endif /* CONFIG_X86_IO_APIC */
319 
320 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
321 {
322 	struct acpi_prt_entry *entry = NULL;
323 	struct pci_dev *bridge;
324 	u8 bridge_pin, orig_pin = pin;
325 	int ret;
326 
327 	ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
328 	if (!ret && entry) {
329 #ifdef CONFIG_X86_IO_APIC
330 		acpi_reroute_boot_interrupt(dev, entry);
331 #endif /* CONFIG_X86_IO_APIC */
332 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
333 				  pci_name(dev), pin_name(pin)));
334 		return entry;
335 	}
336 
337 	/*
338 	 * Attempt to derive an IRQ for this device from a parent bridge's
339 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
340 	 */
341 	bridge = dev->bus->self;
342 	while (bridge) {
343 		pin = pci_swizzle_interrupt_pin(dev, pin);
344 
345 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
346 			/* PC card has the same IRQ as its cardbridge */
347 			bridge_pin = bridge->pin;
348 			if (!bridge_pin) {
349 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
350 						  "No interrupt pin configured for device %s\n",
351 						  pci_name(bridge)));
352 				return NULL;
353 			}
354 			pin = bridge_pin;
355 		}
356 
357 		ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
358 		if (!ret && entry) {
359 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
360 					 "Derived GSI for %s INT %c from %s\n",
361 					 pci_name(dev), pin_name(orig_pin),
362 					 pci_name(bridge)));
363 			return entry;
364 		}
365 
366 		dev = bridge;
367 		bridge = dev->bus->self;
368 	}
369 
370 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
371 		 pin_name(orig_pin));
372 	return NULL;
373 }
374 
375 int acpi_pci_irq_enable(struct pci_dev *dev)
376 {
377 	struct acpi_prt_entry *entry;
378 	int gsi;
379 	u8 pin;
380 	int triggering = ACPI_LEVEL_SENSITIVE;
381 	int polarity = ACPI_ACTIVE_LOW;
382 	char *link = NULL;
383 	char link_desc[16];
384 	int rc;
385 
386 	pin = dev->pin;
387 	if (!pin) {
388 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
389 				  "No interrupt pin configured for device %s\n",
390 				  pci_name(dev)));
391 		return 0;
392 	}
393 
394 	entry = acpi_pci_irq_lookup(dev, pin);
395 	if (!entry) {
396 		/*
397 		 * IDE legacy mode controller IRQs are magic. Why do compat
398 		 * extensions always make such a nasty mess.
399 		 */
400 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
401 				(dev->class & 0x05) == 0)
402 			return 0;
403 	}
404 
405 	if (entry) {
406 		if (entry->link)
407 			gsi = acpi_pci_link_allocate_irq(entry->link,
408 							 entry->index,
409 							 &triggering, &polarity,
410 							 &link);
411 		else
412 			gsi = entry->index;
413 	} else
414 		gsi = -1;
415 
416 	/*
417 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
418 	 * driver reported one, then use it. Exit in any case.
419 	 */
420 	if (gsi < 0) {
421 		u32 dev_gsi;
422 		/* Interrupt Line values above 0xF are forbidden */
423 		if (dev->irq > 0 && (dev->irq <= 0xF) &&
424 		    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
425 			dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
426 				 pin_name(pin), dev->irq);
427 			acpi_register_gsi(&dev->dev, dev_gsi,
428 					  ACPI_LEVEL_SENSITIVE,
429 					  ACPI_ACTIVE_LOW);
430 		} else {
431 			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
432 				 pin_name(pin));
433 		}
434 
435 		return 0;
436 	}
437 
438 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
439 	if (rc < 0) {
440 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
441 			 pin_name(pin));
442 		kfree(entry);
443 		return rc;
444 	}
445 	dev->irq = rc;
446 
447 	if (link)
448 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
449 	else
450 		link_desc[0] = '\0';
451 
452 	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
453 		pin_name(pin), link_desc, gsi,
454 		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
455 		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
456 
457 	kfree(entry);
458 	return 0;
459 }
460 
461 void acpi_pci_irq_disable(struct pci_dev *dev)
462 {
463 	struct acpi_prt_entry *entry;
464 	int gsi;
465 	u8 pin;
466 
467 	pin = dev->pin;
468 	if (!pin)
469 		return;
470 
471 	entry = acpi_pci_irq_lookup(dev, pin);
472 	if (!entry)
473 		return;
474 
475 	if (entry->link)
476 		gsi = acpi_pci_link_free_irq(entry->link);
477 	else
478 		gsi = entry->index;
479 
480 	kfree(entry);
481 
482 	/*
483 	 * TBD: It might be worth clearing dev->irq by magic constant
484 	 * (e.g. PCI_UNDEFINED_IRQ).
485 	 */
486 
487 	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
488 	acpi_unregister_gsi(gsi);
489 }
490