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
44ACPI_MODULE_NAME("pci_irq");
45
46struct 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
54static 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 */
64static 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 */
76static 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 */
88static 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
100struct 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 */
117static 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
129static 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
160static 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
226static 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
264extern int noioapicquirk;
265extern int noioapicreroute;
266
267static 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 */
287static 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
318static 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)
374static 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
391static inline int acpi_isa_register_gsi(struct pci_dev *dev)
392{
393	return -ENODEV;
394}
395#endif
396
397int 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	if (dev->irq_managed && dev->irq > 0)
417		return 0;
418
419	entry = acpi_pci_irq_lookup(dev, pin);
420	if (!entry) {
421		/*
422		 * IDE legacy mode controller IRQs are magic. Why do compat
423		 * extensions always make such a nasty mess.
424		 */
425		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
426				(dev->class & 0x05) == 0)
427			return 0;
428	}
429
430	if (entry) {
431		if (entry->link)
432			gsi = acpi_pci_link_allocate_irq(entry->link,
433							 entry->index,
434							 &triggering, &polarity,
435							 &link);
436		else
437			gsi = entry->index;
438	} else
439		gsi = -1;
440
441	/*
442	 * No IRQ known to the ACPI subsystem - maybe the BIOS /
443	 * driver reported one, then use it. Exit in any case.
444	 */
445	if (gsi < 0) {
446		if (acpi_isa_register_gsi(dev))
447			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
448				 pin_name(pin));
449
450		kfree(entry);
451		return 0;
452	}
453
454	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
455	if (rc < 0) {
456		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
457			 pin_name(pin));
458		kfree(entry);
459		return rc;
460	}
461	dev->irq = rc;
462	dev->irq_managed = 1;
463
464	if (link)
465		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
466	else
467		link_desc[0] = '\0';
468
469	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
470		pin_name(pin), link_desc, gsi,
471		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
472		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
473
474	kfree(entry);
475	return 0;
476}
477
478void acpi_pci_irq_disable(struct pci_dev *dev)
479{
480	struct acpi_prt_entry *entry;
481	int gsi;
482	u8 pin;
483
484	pin = dev->pin;
485	if (!pin || !dev->irq_managed || dev->irq <= 0)
486		return;
487
488	/* Keep IOAPIC pin configuration when suspending */
489	if (dev->dev.power.is_prepared)
490		return;
491#ifdef	CONFIG_PM
492	if (dev->dev.power.runtime_status == RPM_SUSPENDING)
493		return;
494#endif
495
496	entry = acpi_pci_irq_lookup(dev, pin);
497	if (!entry)
498		return;
499
500	if (entry->link)
501		gsi = acpi_pci_link_free_irq(entry->link);
502	else
503		gsi = entry->index;
504
505	kfree(entry);
506
507	/*
508	 * TBD: It might be worth clearing dev->irq by magic constant
509	 * (e.g. PCI_UNDEFINED_IRQ).
510	 */
511
512	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
513	if (gsi >= 0) {
514		acpi_unregister_gsi(gsi);
515		dev->irq_managed = 0;
516	}
517}
518