1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
8 * (c) Copyright 2008 Hewlett-Packard Development Company, L.P.
9 * Bjorn Helgaas <bjorn.helgaas@hp.com>
10 */
11
12
13 #include <linux/dmi.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/types.h>
18 #include <linux/spinlock.h>
19 #include <linux/pm.h>
20 #include <linux/pci.h>
21 #include <linux/acpi.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24
25 #define PREFIX "ACPI: "
26
27 #define _COMPONENT ACPI_PCI_COMPONENT
28 ACPI_MODULE_NAME("pci_irq");
29
30 struct acpi_prt_entry {
31 struct acpi_pci_id id;
32 u8 pin;
33 acpi_handle link;
34 u32 index; /* GSI, or link _CRS index */
35 };
36
pin_name(int pin)37 static inline char pin_name(int pin)
38 {
39 return 'A' + pin - 1;
40 }
41
42 /* --------------------------------------------------------------------------
43 PCI IRQ Routing Table (PRT) Support
44 -------------------------------------------------------------------------- */
45
46 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
47 static const struct dmi_system_id medion_md9580[] = {
48 {
49 .ident = "Medion MD9580-F laptop",
50 .matches = {
51 DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
52 DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
53 },
54 },
55 { }
56 };
57
58 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
59 static const struct dmi_system_id dell_optiplex[] = {
60 {
61 .ident = "Dell Optiplex GX1",
62 .matches = {
63 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
64 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
65 },
66 },
67 { }
68 };
69
70 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
71 static const struct dmi_system_id hp_t5710[] = {
72 {
73 .ident = "HP t5710",
74 .matches = {
75 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
76 DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
77 DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
78 },
79 },
80 { }
81 };
82
83 struct prt_quirk {
84 const struct dmi_system_id *system;
85 unsigned int segment;
86 unsigned int bus;
87 unsigned int device;
88 unsigned char pin;
89 const char *source; /* according to BIOS */
90 const char *actual_source;
91 };
92
93 #define PCI_INTX_PIN(c) (c - 'A' + 1)
94
95 /*
96 * These systems have incorrect _PRT entries. The BIOS claims the PCI
97 * interrupt at the listed segment/bus/device/pin is connected to the first
98 * link device, but it is actually connected to the second.
99 */
100 static const struct prt_quirk prt_quirks[] = {
101 { medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
102 "\\_SB_.PCI0.ISA_.LNKA",
103 "\\_SB_.PCI0.ISA_.LNKB"},
104 { dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
105 "\\_SB_.LNKB",
106 "\\_SB_.LNKA"},
107 { hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
108 "\\_SB_.PCI0.LNK1",
109 "\\_SB_.PCI0.LNK3"},
110 };
111
do_prt_fixups(struct acpi_prt_entry * entry,struct acpi_pci_routing_table * prt)112 static void do_prt_fixups(struct acpi_prt_entry *entry,
113 struct acpi_pci_routing_table *prt)
114 {
115 int i;
116 const struct prt_quirk *quirk;
117
118 for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
119 quirk = &prt_quirks[i];
120
121 /* All current quirks involve link devices, not GSIs */
122 if (dmi_check_system(quirk->system) &&
123 entry->id.segment == quirk->segment &&
124 entry->id.bus == quirk->bus &&
125 entry->id.device == quirk->device &&
126 entry->pin == quirk->pin &&
127 !strcmp(prt->source, quirk->source) &&
128 strlen(prt->source) >= strlen(quirk->actual_source)) {
129 printk(KERN_WARNING PREFIX "firmware reports "
130 "%04x:%02x:%02x PCI INT %c connected to %s; "
131 "changing to %s\n",
132 entry->id.segment, entry->id.bus,
133 entry->id.device, pin_name(entry->pin),
134 prt->source, quirk->actual_source);
135 strcpy(prt->source, quirk->actual_source);
136 }
137 }
138 }
139
acpi_pci_irq_check_entry(acpi_handle handle,struct pci_dev * dev,int pin,struct acpi_pci_routing_table * prt,struct acpi_prt_entry ** entry_ptr)140 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
141 int pin, struct acpi_pci_routing_table *prt,
142 struct acpi_prt_entry **entry_ptr)
143 {
144 int segment = pci_domain_nr(dev->bus);
145 int bus = dev->bus->number;
146 int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn);
147 struct acpi_prt_entry *entry;
148
149 if (((prt->address >> 16) & 0xffff) != device ||
150 prt->pin + 1 != pin)
151 return -ENODEV;
152
153 entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
154 if (!entry)
155 return -ENOMEM;
156
157 /*
158 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
159 * 1=INTA, 2=INTB. We use the PCI encoding throughout, so convert
160 * it here.
161 */
162 entry->id.segment = segment;
163 entry->id.bus = bus;
164 entry->id.device = (prt->address >> 16) & 0xFFFF;
165 entry->pin = prt->pin + 1;
166
167 do_prt_fixups(entry, prt);
168
169 entry->index = prt->source_index;
170
171 /*
172 * Type 1: Dynamic
173 * ---------------
174 * The 'source' field specifies the PCI interrupt link device used to
175 * configure the IRQ assigned to this slot|dev|pin. The 'source_index'
176 * indicates which resource descriptor in the resource template (of
177 * the link device) this interrupt is allocated from.
178 *
179 * NOTE: Don't query the Link Device for IRQ information at this time
180 * because Link Device enumeration may not have occurred yet
181 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI
182 * namespace).
183 */
184 if (prt->source[0])
185 acpi_get_handle(handle, prt->source, &entry->link);
186
187 /*
188 * Type 2: Static
189 * --------------
190 * The 'source' field is NULL, and the 'source_index' field specifies
191 * the IRQ value, which is hardwired to specific interrupt inputs on
192 * the interrupt controller.
193 */
194
195 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
196 " %04x:%02x:%02x[%c] -> %s[%d]\n",
197 entry->id.segment, entry->id.bus,
198 entry->id.device, pin_name(entry->pin),
199 prt->source, entry->index));
200
201 *entry_ptr = entry;
202
203 return 0;
204 }
205
acpi_pci_irq_find_prt_entry(struct pci_dev * dev,int pin,struct acpi_prt_entry ** entry_ptr)206 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
207 int pin, struct acpi_prt_entry **entry_ptr)
208 {
209 acpi_status status;
210 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
211 struct acpi_pci_routing_table *entry;
212 acpi_handle handle = NULL;
213
214 if (dev->bus->bridge)
215 handle = ACPI_HANDLE(dev->bus->bridge);
216
217 if (!handle)
218 return -ENODEV;
219
220 /* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
221 status = acpi_get_irq_routing_table(handle, &buffer);
222 if (ACPI_FAILURE(status)) {
223 kfree(buffer.pointer);
224 return -ENODEV;
225 }
226
227 entry = buffer.pointer;
228 while (entry && (entry->length > 0)) {
229 if (!acpi_pci_irq_check_entry(handle, dev, pin,
230 entry, entry_ptr))
231 break;
232 entry = (struct acpi_pci_routing_table *)
233 ((unsigned long)entry + entry->length);
234 }
235
236 kfree(buffer.pointer);
237 return 0;
238 }
239
240 /* --------------------------------------------------------------------------
241 PCI Interrupt Routing Support
242 -------------------------------------------------------------------------- */
243 #ifdef CONFIG_X86_IO_APIC
244 extern int noioapicquirk;
245 extern int noioapicreroute;
246
bridge_has_boot_interrupt_variant(struct pci_bus * bus)247 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
248 {
249 struct pci_bus *bus_it;
250
251 for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
252 if (!bus_it->self)
253 return 0;
254 if (bus_it->self->irq_reroute_variant)
255 return bus_it->self->irq_reroute_variant;
256 }
257 return 0;
258 }
259
260 /*
261 * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
262 * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
263 * during interrupt handling). When this INTx generation cannot be disabled,
264 * we reroute these interrupts to their legacy equivalent to get rid of
265 * spurious interrupts.
266 */
acpi_reroute_boot_interrupt(struct pci_dev * dev,struct acpi_prt_entry * entry)267 static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
268 struct acpi_prt_entry *entry)
269 {
270 if (noioapicquirk || noioapicreroute) {
271 return 0;
272 } else {
273 switch (bridge_has_boot_interrupt_variant(dev->bus)) {
274 case 0:
275 /* no rerouting necessary */
276 return 0;
277 case INTEL_IRQ_REROUTE_VARIANT:
278 /*
279 * Remap according to INTx routing table in 6700PXH
280 * specs, intel order number 302628-002, section
281 * 2.15.2. Other chipsets (80332, ...) have the same
282 * mapping and are handled here as well.
283 */
284 dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
285 "IRQ %d\n", entry->index,
286 (entry->index % 4) + 16);
287 entry->index = (entry->index % 4) + 16;
288 return 1;
289 default:
290 dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
291 "IRQ: unknown mapping\n", entry->index);
292 return -1;
293 }
294 }
295 }
296 #endif /* CONFIG_X86_IO_APIC */
297
acpi_pci_irq_lookup(struct pci_dev * dev,int pin)298 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
299 {
300 struct acpi_prt_entry *entry = NULL;
301 struct pci_dev *bridge;
302 u8 bridge_pin, orig_pin = pin;
303 int ret;
304
305 ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
306 if (!ret && entry) {
307 #ifdef CONFIG_X86_IO_APIC
308 acpi_reroute_boot_interrupt(dev, entry);
309 #endif /* CONFIG_X86_IO_APIC */
310 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
311 pci_name(dev), pin_name(pin)));
312 return entry;
313 }
314
315 /*
316 * Attempt to derive an IRQ for this device from a parent bridge's
317 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
318 */
319 bridge = dev->bus->self;
320 while (bridge) {
321 pin = pci_swizzle_interrupt_pin(dev, pin);
322
323 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
324 /* PC card has the same IRQ as its cardbridge */
325 bridge_pin = bridge->pin;
326 if (!bridge_pin) {
327 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
328 "No interrupt pin configured for device %s\n",
329 pci_name(bridge)));
330 return NULL;
331 }
332 pin = bridge_pin;
333 }
334
335 ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
336 if (!ret && entry) {
337 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
338 "Derived GSI for %s INT %c from %s\n",
339 pci_name(dev), pin_name(orig_pin),
340 pci_name(bridge)));
341 return entry;
342 }
343
344 dev = bridge;
345 bridge = dev->bus->self;
346 }
347
348 dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
349 pin_name(orig_pin));
350 return NULL;
351 }
352
353 #if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
acpi_isa_register_gsi(struct pci_dev * dev)354 static int acpi_isa_register_gsi(struct pci_dev *dev)
355 {
356 u32 dev_gsi;
357
358 /* Interrupt Line values above 0xF are forbidden */
359 if (dev->irq > 0 && (dev->irq <= 0xF) &&
360 acpi_isa_irq_available(dev->irq) &&
361 (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
362 dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
363 pin_name(dev->pin), dev->irq);
364 acpi_register_gsi(&dev->dev, dev_gsi,
365 ACPI_LEVEL_SENSITIVE,
366 ACPI_ACTIVE_LOW);
367 return 0;
368 }
369 return -EINVAL;
370 }
371 #else
acpi_isa_register_gsi(struct pci_dev * dev)372 static inline int acpi_isa_register_gsi(struct pci_dev *dev)
373 {
374 return -ENODEV;
375 }
376 #endif
377
acpi_pci_irq_valid(struct pci_dev * dev,u8 pin)378 static inline bool acpi_pci_irq_valid(struct pci_dev *dev, u8 pin)
379 {
380 #ifdef CONFIG_X86
381 /*
382 * On x86 irq line 0xff means "unknown" or "no connection"
383 * (PCI 3.0, Section 6.2.4, footnote on page 223).
384 */
385 if (dev->irq == 0xff) {
386 dev->irq = IRQ_NOTCONNECTED;
387 dev_warn(&dev->dev, "PCI INT %c: not connected\n",
388 pin_name(pin));
389 return false;
390 }
391 #endif
392 return true;
393 }
394
acpi_pci_irq_enable(struct pci_dev * dev)395 int acpi_pci_irq_enable(struct pci_dev *dev)
396 {
397 struct acpi_prt_entry *entry;
398 int gsi;
399 u8 pin;
400 int triggering = ACPI_LEVEL_SENSITIVE;
401 /*
402 * On ARM systems with the GIC interrupt model, level interrupts
403 * are always polarity high by specification; PCI legacy
404 * IRQs lines are inverted before reaching the interrupt
405 * controller and must therefore be considered active high
406 * as default.
407 */
408 int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ?
409 ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW;
410 char *link = NULL;
411 char link_desc[16];
412 int rc;
413
414 pin = dev->pin;
415 if (!pin) {
416 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
417 "No interrupt pin configured for device %s\n",
418 pci_name(dev)));
419 return 0;
420 }
421
422 if (dev->irq_managed && dev->irq > 0)
423 return 0;
424
425 entry = acpi_pci_irq_lookup(dev, pin);
426 if (!entry) {
427 /*
428 * IDE legacy mode controller IRQs are magic. Why do compat
429 * extensions always make such a nasty mess.
430 */
431 if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
432 (dev->class & 0x05) == 0)
433 return 0;
434 }
435
436 if (entry) {
437 if (entry->link)
438 gsi = acpi_pci_link_allocate_irq(entry->link,
439 entry->index,
440 &triggering, &polarity,
441 &link);
442 else
443 gsi = entry->index;
444 } else
445 gsi = -1;
446
447 if (gsi < 0) {
448 /*
449 * No IRQ known to the ACPI subsystem - maybe the BIOS /
450 * driver reported one, then use it. Exit in any case.
451 */
452 if (!acpi_pci_irq_valid(dev, pin)) {
453 kfree(entry);
454 return 0;
455 }
456
457 if (acpi_isa_register_gsi(dev))
458 dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
459 pin_name(pin));
460
461 kfree(entry);
462 return 0;
463 }
464
465 rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
466 if (rc < 0) {
467 dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
468 pin_name(pin));
469 kfree(entry);
470 return rc;
471 }
472 dev->irq = rc;
473 dev->irq_managed = 1;
474
475 if (link)
476 snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
477 else
478 link_desc[0] = '\0';
479
480 dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
481 pin_name(pin), link_desc, gsi,
482 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
483 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
484
485 kfree(entry);
486 return 0;
487 }
488
acpi_pci_irq_disable(struct pci_dev * dev)489 void acpi_pci_irq_disable(struct pci_dev *dev)
490 {
491 struct acpi_prt_entry *entry;
492 int gsi;
493 u8 pin;
494
495 pin = dev->pin;
496 if (!pin || !dev->irq_managed || dev->irq <= 0)
497 return;
498
499 /* Keep IOAPIC pin configuration when suspending */
500 if (dev->dev.power.is_prepared)
501 return;
502 #ifdef CONFIG_PM
503 if (dev->dev.power.runtime_status == RPM_SUSPENDING)
504 return;
505 #endif
506
507 entry = acpi_pci_irq_lookup(dev, pin);
508 if (!entry)
509 return;
510
511 if (entry->link)
512 gsi = acpi_pci_link_free_irq(entry->link);
513 else
514 gsi = entry->index;
515
516 kfree(entry);
517
518 /*
519 * TBD: It might be worth clearing dev->irq by magic constant
520 * (e.g. PCI_UNDEFINED_IRQ).
521 */
522
523 dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
524 if (gsi >= 0) {
525 acpi_unregister_gsi(gsi);
526 dev->irq_managed = 0;
527 }
528 }
529