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