2 * pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
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>
10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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.
26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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>
37 #include <linux/pci.h>
38 #include <linux/acpi.h>
39 #include <linux/slab.h>
41 #define PREFIX "ACPI: "
43 #define _COMPONENT ACPI_PCI_COMPONENT
44 ACPI_MODULE_NAME("pci_irq");
46 struct acpi_prt_entry {
47 struct acpi_pci_id id;
50 u32 index; /* GSI, or link _CRS index */
53 static inline char pin_name(int pin)
58 /* --------------------------------------------------------------------------
59 PCI IRQ Routing Table (PRT) Support
60 -------------------------------------------------------------------------- */
62 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
63 static const struct dmi_system_id medion_md9580[] = {
65 .ident = "Medion MD9580-F laptop",
67 DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
68 DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
74 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
75 static const struct dmi_system_id dell_optiplex[] = {
77 .ident = "Dell Optiplex GX1",
79 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
80 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
86 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
87 static const struct dmi_system_id hp_t5710[] = {
91 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
92 DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
93 DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
100 const struct dmi_system_id *system;
101 unsigned int segment;
105 const char *source; /* according to BIOS */
106 const char *actual_source;
109 #define PCI_INTX_PIN(c) (c - 'A' + 1)
112 * These systems have incorrect _PRT entries. The BIOS claims the PCI
113 * interrupt at the listed segment/bus/device/pin is connected to the first
114 * link device, but it is actually connected to the second.
116 static const struct prt_quirk prt_quirks[] = {
117 { medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
118 "\\_SB_.PCI0.ISA_.LNKA",
119 "\\_SB_.PCI0.ISA_.LNKB"},
120 { dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
123 { hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
128 static void do_prt_fixups(struct acpi_prt_entry *entry,
129 struct acpi_pci_routing_table *prt)
132 const struct prt_quirk *quirk;
134 for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
135 quirk = &prt_quirks[i];
137 /* All current quirks involve link devices, not GSIs */
141 if (dmi_check_system(quirk->system) &&
142 entry->id.segment == quirk->segment &&
143 entry->id.bus == quirk->bus &&
144 entry->id.device == quirk->device &&
145 entry->pin == quirk->pin &&
146 !strcmp(prt->source, quirk->source) &&
147 strlen(prt->source) >= strlen(quirk->actual_source)) {
148 printk(KERN_WARNING PREFIX "firmware reports "
149 "%04x:%02x:%02x PCI INT %c connected to %s; "
151 entry->id.segment, entry->id.bus,
152 entry->id.device, pin_name(entry->pin),
153 prt->source, quirk->actual_source);
154 strcpy(prt->source, quirk->actual_source);
159 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
160 int pin, struct acpi_pci_routing_table *prt,
161 struct acpi_prt_entry **entry_ptr)
163 int segment = pci_domain_nr(dev->bus);
164 int bus = dev->bus->number;
165 int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn);
166 struct acpi_prt_entry *entry;
168 if (((prt->address >> 16) & 0xffff) != device ||
172 entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
177 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
178 * 1=INTA, 2=INTB. We use the PCI encoding throughout, so convert
181 entry->id.segment = segment;
183 entry->id.device = (prt->address >> 16) & 0xFFFF;
184 entry->pin = prt->pin + 1;
186 do_prt_fixups(entry, prt);
188 entry->index = prt->source_index;
193 * The 'source' field specifies the PCI interrupt link device used to
194 * configure the IRQ assigned to this slot|dev|pin. The 'source_index'
195 * indicates which resource descriptor in the resource template (of
196 * the link device) this interrupt is allocated from.
198 * NOTE: Don't query the Link Device for IRQ information at this time
199 * because Link Device enumeration may not have occurred yet
200 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI
204 acpi_get_handle(handle, prt->source, &entry->link);
209 * The 'source' field is NULL, and the 'source_index' field specifies
210 * the IRQ value, which is hardwired to specific interrupt inputs on
211 * the interrupt controller.
214 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
215 " %04x:%02x:%02x[%c] -> %s[%d]\n",
216 entry->id.segment, entry->id.bus,
217 entry->id.device, pin_name(entry->pin),
218 prt->source, entry->index));
225 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
226 int pin, struct acpi_prt_entry **entry_ptr)
229 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
230 struct acpi_pci_routing_table *entry;
231 acpi_handle handle = NULL;
233 if (dev->bus->bridge)
234 handle = ACPI_HANDLE(dev->bus->bridge);
239 /* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
240 status = acpi_get_irq_routing_table(handle, &buffer);
241 if (ACPI_FAILURE(status)) {
242 kfree(buffer.pointer);
246 entry = buffer.pointer;
247 while (entry && (entry->length > 0)) {
248 if (!acpi_pci_irq_check_entry(handle, dev, pin,
251 entry = (struct acpi_pci_routing_table *)
252 ((unsigned long)entry + entry->length);
255 kfree(buffer.pointer);
259 /* --------------------------------------------------------------------------
260 PCI Interrupt Routing Support
261 -------------------------------------------------------------------------- */
262 #ifdef CONFIG_X86_IO_APIC
263 extern int noioapicquirk;
264 extern int noioapicreroute;
266 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
268 struct pci_bus *bus_it;
270 for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
273 if (bus_it->self->irq_reroute_variant)
274 return bus_it->self->irq_reroute_variant;
280 * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
281 * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
282 * during interrupt handling). When this INTx generation cannot be disabled,
283 * we reroute these interrupts to their legacy equivalent to get rid of
284 * spurious interrupts.
286 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
287 struct acpi_prt_entry *entry)
289 if (noioapicquirk || noioapicreroute) {
292 switch (bridge_has_boot_interrupt_variant(dev->bus)) {
294 /* no rerouting necessary */
296 case INTEL_IRQ_REROUTE_VARIANT:
298 * Remap according to INTx routing table in 6700PXH
299 * specs, intel order number 302628-002, section
300 * 2.15.2. Other chipsets (80332, ...) have the same
301 * mapping and are handled here as well.
303 dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
304 "IRQ %d\n", entry->index,
305 (entry->index % 4) + 16);
306 entry->index = (entry->index % 4) + 16;
309 dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
310 "IRQ: unknown mapping\n", entry->index);
315 #endif /* CONFIG_X86_IO_APIC */
317 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
319 struct acpi_prt_entry *entry = NULL;
320 struct pci_dev *bridge;
321 u8 bridge_pin, orig_pin = pin;
324 ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
326 #ifdef CONFIG_X86_IO_APIC
327 acpi_reroute_boot_interrupt(dev, entry);
328 #endif /* CONFIG_X86_IO_APIC */
329 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
330 pci_name(dev), pin_name(pin)));
335 * Attempt to derive an IRQ for this device from a parent bridge's
336 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
338 bridge = dev->bus->self;
340 pin = pci_swizzle_interrupt_pin(dev, pin);
342 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
343 /* PC card has the same IRQ as its cardbridge */
344 bridge_pin = bridge->pin;
346 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
347 "No interrupt pin configured for device %s\n",
354 ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
356 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
357 "Derived GSI for %s INT %c from %s\n",
358 pci_name(dev), pin_name(orig_pin),
364 bridge = dev->bus->self;
367 dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
372 #if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
373 static int acpi_isa_register_gsi(struct pci_dev *dev)
377 /* Interrupt Line values above 0xF are forbidden */
378 if (dev->irq > 0 && (dev->irq <= 0xF) &&
379 (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
380 dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
381 pin_name(dev->pin), dev->irq);
382 acpi_register_gsi(&dev->dev, dev_gsi,
383 ACPI_LEVEL_SENSITIVE,
390 static inline int acpi_isa_register_gsi(struct pci_dev *dev)
396 int acpi_pci_irq_enable(struct pci_dev *dev)
398 struct acpi_prt_entry *entry;
401 int triggering = ACPI_LEVEL_SENSITIVE;
402 int polarity = ACPI_ACTIVE_LOW;
409 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
410 "No interrupt pin configured for device %s\n",
415 if (dev->irq_managed && dev->irq > 0)
418 entry = acpi_pci_irq_lookup(dev, pin);
421 * IDE legacy mode controller IRQs are magic. Why do compat
422 * extensions always make such a nasty mess.
424 if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
425 (dev->class & 0x05) == 0)
431 gsi = acpi_pci_link_allocate_irq(entry->link,
433 &triggering, &polarity,
441 * No IRQ known to the ACPI subsystem - maybe the BIOS /
442 * driver reported one, then use it. Exit in any case.
445 if (acpi_isa_register_gsi(dev))
446 dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
453 rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
455 dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
461 dev->irq_managed = 1;
464 snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
468 dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
469 pin_name(pin), link_desc, gsi,
470 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
471 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
477 void acpi_pci_irq_disable(struct pci_dev *dev)
479 struct acpi_prt_entry *entry;
484 if (!pin || !dev->irq_managed || dev->irq <= 0)
487 entry = acpi_pci_irq_lookup(dev, pin);
492 gsi = acpi_pci_link_free_irq(entry->link);
499 * TBD: It might be worth clearing dev->irq by magic constant
500 * (e.g. PCI_UNDEFINED_IRQ).
503 dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
505 acpi_unregister_gsi(gsi);
506 dev->irq_managed = 0;