Linux 5.3-rc8
[sfrench/cifs-2.6.git] / drivers / acpi / pci_irq.c
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
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
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
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
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
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  */
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
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)
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
372 static inline int acpi_isa_register_gsi(struct pci_dev *dev)
373 {
374         return -ENODEV;
375 }
376 #endif
377
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
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                         return 0;
454
455                 if (acpi_isa_register_gsi(dev))
456                         dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
457                                  pin_name(pin));
458
459                 kfree(entry);
460                 return 0;
461         }
462
463         rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
464         if (rc < 0) {
465                 dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
466                          pin_name(pin));
467                 kfree(entry);
468                 return rc;
469         }
470         dev->irq = rc;
471         dev->irq_managed = 1;
472
473         if (link)
474                 snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
475         else
476                 link_desc[0] = '\0';
477
478         dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
479                 pin_name(pin), link_desc, gsi,
480                 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
481                 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
482
483         kfree(entry);
484         return 0;
485 }
486
487 void acpi_pci_irq_disable(struct pci_dev *dev)
488 {
489         struct acpi_prt_entry *entry;
490         int gsi;
491         u8 pin;
492
493         pin = dev->pin;
494         if (!pin || !dev->irq_managed || dev->irq <= 0)
495                 return;
496
497         /* Keep IOAPIC pin configuration when suspending */
498         if (dev->dev.power.is_prepared)
499                 return;
500 #ifdef  CONFIG_PM
501         if (dev->dev.power.runtime_status == RPM_SUSPENDING)
502                 return;
503 #endif
504
505         entry = acpi_pci_irq_lookup(dev, pin);
506         if (!entry)
507                 return;
508
509         if (entry->link)
510                 gsi = acpi_pci_link_free_irq(entry->link);
511         else
512                 gsi = entry->index;
513
514         kfree(entry);
515
516         /*
517          * TBD: It might be worth clearing dev->irq by magic constant
518          * (e.g. PCI_UNDEFINED_IRQ).
519          */
520
521         dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
522         if (gsi >= 0) {
523                 acpi_unregister_gsi(gsi);
524                 dev->irq_managed = 0;
525         }
526 }