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                         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
 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 }