xref: /openbmc/linux/drivers/acpi/pci_irq.c (revision b627b4ed)
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/proc_fs.h>
36 #include <linux/spinlock.h>
37 #include <linux/pm.h>
38 #include <linux/pci.h>
39 #include <linux/acpi.h>
40 #include <acpi/acpi_bus.h>
41 #include <acpi/acpi_drivers.h>
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 LIST_HEAD(acpi_prt_list);
55 static DEFINE_SPINLOCK(acpi_prt_lock);
56 
57 static inline char pin_name(int pin)
58 {
59 	return 'A' + pin - 1;
60 }
61 
62 /* --------------------------------------------------------------------------
63                          PCI IRQ Routing Table (PRT) Support
64    -------------------------------------------------------------------------- */
65 
66 static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
67 							  int pin)
68 {
69 	struct acpi_prt_entry *entry;
70 	int segment = pci_domain_nr(dev->bus);
71 	int bus = dev->bus->number;
72 	int device = PCI_SLOT(dev->devfn);
73 
74 	spin_lock(&acpi_prt_lock);
75 	list_for_each_entry(entry, &acpi_prt_list, list) {
76 		if ((segment == entry->id.segment)
77 		    && (bus == entry->id.bus)
78 		    && (device == entry->id.device)
79 		    && (pin == entry->pin)) {
80 			spin_unlock(&acpi_prt_lock);
81 			return entry;
82 		}
83 	}
84 	spin_unlock(&acpi_prt_lock);
85 	return NULL;
86 }
87 
88 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
89 static const struct dmi_system_id medion_md9580[] = {
90 	{
91 		.ident = "Medion MD9580-F laptop",
92 		.matches = {
93 			DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
94 			DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
95 		},
96 	},
97 	{ }
98 };
99 
100 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
101 static const struct dmi_system_id dell_optiplex[] = {
102 	{
103 		.ident = "Dell Optiplex GX1",
104 		.matches = {
105 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
106 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
107 		},
108 	},
109 	{ }
110 };
111 
112 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
113 static const struct dmi_system_id hp_t5710[] = {
114 	{
115 		.ident = "HP t5710",
116 		.matches = {
117 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
118 			DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
119 			DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
120 		},
121 	},
122 	{ }
123 };
124 
125 struct prt_quirk {
126 	const struct dmi_system_id *system;
127 	unsigned int		segment;
128 	unsigned int		bus;
129 	unsigned int		device;
130 	unsigned char		pin;
131 	const char		*source;	/* according to BIOS */
132 	const char		*actual_source;
133 };
134 
135 #define PCI_INTX_PIN(c)		(c - 'A' + 1)
136 
137 /*
138  * These systems have incorrect _PRT entries.  The BIOS claims the PCI
139  * interrupt at the listed segment/bus/device/pin is connected to the first
140  * link device, but it is actually connected to the second.
141  */
142 static const struct prt_quirk prt_quirks[] = {
143 	{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
144 		"\\_SB_.PCI0.ISA_.LNKA",
145 		"\\_SB_.PCI0.ISA_.LNKB"},
146 	{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
147 		"\\_SB_.LNKB",
148 		"\\_SB_.LNKA"},
149 	{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
150 		"\\_SB_.PCI0.LNK1",
151 		"\\_SB_.PCI0.LNK3"},
152 };
153 
154 static void do_prt_fixups(struct acpi_prt_entry *entry,
155 			  struct acpi_pci_routing_table *prt)
156 {
157 	int i;
158 	const struct prt_quirk *quirk;
159 
160 	for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
161 		quirk = &prt_quirks[i];
162 
163 		/* All current quirks involve link devices, not GSIs */
164 		if (!prt->source)
165 			continue;
166 
167 		if (dmi_check_system(quirk->system) &&
168 		    entry->id.segment == quirk->segment &&
169 		    entry->id.bus == quirk->bus &&
170 		    entry->id.device == quirk->device &&
171 		    entry->pin == quirk->pin &&
172 		    !strcmp(prt->source, quirk->source) &&
173 		    strlen(prt->source) >= strlen(quirk->actual_source)) {
174 			printk(KERN_WARNING PREFIX "firmware reports "
175 				"%04x:%02x:%02x PCI INT %c connected to %s; "
176 				"changing to %s\n",
177 				entry->id.segment, entry->id.bus,
178 				entry->id.device, pin_name(entry->pin),
179 				prt->source, quirk->actual_source);
180 			strcpy(prt->source, quirk->actual_source);
181 		}
182 	}
183 }
184 
185 static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
186 				  struct acpi_pci_routing_table *prt)
187 {
188 	struct acpi_prt_entry *entry;
189 
190 	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
191 	if (!entry)
192 		return -ENOMEM;
193 
194 	/*
195 	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
196 	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
197 	 * it here.
198 	 */
199 	entry->id.segment = segment;
200 	entry->id.bus = bus;
201 	entry->id.device = (prt->address >> 16) & 0xFFFF;
202 	entry->pin = prt->pin + 1;
203 
204 	do_prt_fixups(entry, prt);
205 
206 	entry->index = prt->source_index;
207 
208 	/*
209 	 * Type 1: Dynamic
210 	 * ---------------
211 	 * The 'source' field specifies the PCI interrupt link device used to
212 	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
213 	 * indicates which resource descriptor in the resource template (of
214 	 * the link device) this interrupt is allocated from.
215 	 *
216 	 * NOTE: Don't query the Link Device for IRQ information at this time
217 	 *       because Link Device enumeration may not have occurred yet
218 	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
219 	 *       namespace).
220 	 */
221 	if (prt->source[0])
222 		acpi_get_handle(handle, prt->source, &entry->link);
223 
224 	/*
225 	 * Type 2: Static
226 	 * --------------
227 	 * The 'source' field is NULL, and the 'source_index' field specifies
228 	 * the IRQ value, which is hardwired to specific interrupt inputs on
229 	 * the interrupt controller.
230 	 */
231 
232 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
233 			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
234 			      entry->id.segment, entry->id.bus,
235 			      entry->id.device, pin_name(entry->pin),
236 			      prt->source, entry->index));
237 
238 	spin_lock(&acpi_prt_lock);
239 	list_add_tail(&entry->list, &acpi_prt_list);
240 	spin_unlock(&acpi_prt_lock);
241 
242 	return 0;
243 }
244 
245 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
246 {
247 	acpi_status status;
248 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
249 	struct acpi_pci_routing_table *entry;
250 
251 	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
252 	status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
253 	if (ACPI_FAILURE(status))
254 		return -ENODEV;
255 
256 	printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
257 	       (char *) buffer.pointer);
258 
259 	kfree(buffer.pointer);
260 
261 	buffer.length = ACPI_ALLOCATE_BUFFER;
262 	buffer.pointer = NULL;
263 
264 	status = acpi_get_irq_routing_table(handle, &buffer);
265 	if (ACPI_FAILURE(status)) {
266 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
267 				acpi_format_exception(status)));
268 		kfree(buffer.pointer);
269 		return -ENODEV;
270 	}
271 
272 	entry = buffer.pointer;
273 	while (entry && (entry->length > 0)) {
274 		acpi_pci_irq_add_entry(handle, segment, bus, entry);
275 		entry = (struct acpi_pci_routing_table *)
276 		    ((unsigned long)entry + entry->length);
277 	}
278 
279 	kfree(buffer.pointer);
280 	return 0;
281 }
282 
283 void acpi_pci_irq_del_prt(int segment, int bus)
284 {
285 	struct acpi_prt_entry *entry, *tmp;
286 
287 	printk(KERN_DEBUG
288 	       "ACPI: Delete PCI Interrupt Routing Table for %04x:%02x\n",
289 	       segment, bus);
290 	spin_lock(&acpi_prt_lock);
291 	list_for_each_entry_safe(entry, tmp, &acpi_prt_list, list) {
292 		if (segment == entry->id.segment && bus == entry->id.bus) {
293 			list_del(&entry->list);
294 			kfree(entry);
295 		}
296 	}
297 	spin_unlock(&acpi_prt_lock);
298 }
299 
300 /* --------------------------------------------------------------------------
301                           PCI Interrupt Routing Support
302    -------------------------------------------------------------------------- */
303 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
304 {
305 	struct acpi_prt_entry *entry;
306 	struct pci_dev *bridge;
307 	u8 bridge_pin, orig_pin = pin;
308 
309 	entry = acpi_pci_irq_find_prt_entry(dev, pin);
310 	if (entry) {
311 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
312 				  pci_name(dev), pin_name(pin)));
313 		return entry;
314 	}
315 
316 	/*
317 	 * Attempt to derive an IRQ for this device from a parent bridge's
318 	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
319 	 */
320 	bridge = dev->bus->self;
321 	while (bridge) {
322 		pin = pci_swizzle_interrupt_pin(dev, pin);
323 
324 		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
325 			/* PC card has the same IRQ as its cardbridge */
326 			bridge_pin = bridge->pin;
327 			if (!bridge_pin) {
328 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
329 						  "No interrupt pin configured for device %s\n",
330 						  pci_name(bridge)));
331 				return NULL;
332 			}
333 			pin = bridge_pin;
334 		}
335 
336 		entry = acpi_pci_irq_find_prt_entry(bridge, pin);
337 		if (entry) {
338 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
339 					 "Derived GSI for %s INT %c from %s\n",
340 					 pci_name(dev), pin_name(orig_pin),
341 					 pci_name(bridge)));
342 			return entry;
343 		}
344 
345 		dev = bridge;
346 		bridge = dev->bus->self;
347 	}
348 
349 	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
350 		 pin_name(orig_pin));
351 	return NULL;
352 }
353 
354 int acpi_pci_irq_enable(struct pci_dev *dev)
355 {
356 	struct acpi_prt_entry *entry;
357 	int gsi;
358 	u8 pin;
359 	int triggering = ACPI_LEVEL_SENSITIVE;
360 	int polarity = ACPI_ACTIVE_LOW;
361 	char *link = NULL;
362 	char link_desc[16];
363 	int rc;
364 
365 	pin = dev->pin;
366 	if (!pin) {
367 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
368 				  "No interrupt pin configured for device %s\n",
369 				  pci_name(dev)));
370 		return 0;
371 	}
372 
373 	entry = acpi_pci_irq_lookup(dev, pin);
374 	if (!entry) {
375 		/*
376 		 * IDE legacy mode controller IRQs are magic. Why do compat
377 		 * extensions always make such a nasty mess.
378 		 */
379 		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
380 				(dev->class & 0x05) == 0)
381 			return 0;
382 	}
383 
384 	if (entry) {
385 		if (entry->link)
386 			gsi = acpi_pci_link_allocate_irq(entry->link,
387 							 entry->index,
388 							 &triggering, &polarity,
389 							 &link);
390 		else
391 			gsi = entry->index;
392 	} else
393 		gsi = -1;
394 
395 	/*
396 	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
397 	 * driver reported one, then use it. Exit in any case.
398 	 */
399 	if (gsi < 0) {
400 		dev_warn(&dev->dev, "PCI INT %c: no GSI", pin_name(pin));
401 		/* Interrupt Line values above 0xF are forbidden */
402 		if (dev->irq > 0 && (dev->irq <= 0xF)) {
403 			printk(" - using IRQ %d\n", dev->irq);
404 			acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
405 					  ACPI_ACTIVE_LOW);
406 			return 0;
407 		} else {
408 			printk("\n");
409 			return 0;
410 		}
411 	}
412 
413 	rc = acpi_register_gsi(gsi, triggering, polarity);
414 	if (rc < 0) {
415 		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
416 			 pin_name(pin));
417 		return rc;
418 	}
419 	dev->irq = rc;
420 
421 	if (link)
422 		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
423 	else
424 		link_desc[0] = '\0';
425 
426 	dev_info(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
427 		 pin_name(pin), link_desc, gsi,
428 		 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
429 		 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
430 
431 	return 0;
432 }
433 
434 /* FIXME: implement x86/x86_64 version */
435 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
436 {
437 }
438 
439 void acpi_pci_irq_disable(struct pci_dev *dev)
440 {
441 	struct acpi_prt_entry *entry;
442 	int gsi;
443 	u8 pin;
444 
445 	pin = dev->pin;
446 	if (!pin)
447 		return;
448 
449 	entry = acpi_pci_irq_lookup(dev, pin);
450 	if (!entry)
451 		return;
452 
453 	if (entry->link)
454 		gsi = acpi_pci_link_free_irq(entry->link);
455 	else
456 		gsi = entry->index;
457 
458 	/*
459 	 * TBD: It might be worth clearing dev->irq by magic constant
460 	 * (e.g. PCI_UNDEFINED_IRQ).
461 	 */
462 
463 	dev_info(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
464 	acpi_unregister_gsi(gsi);
465 }
466