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 #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(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(prt->source, 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(dev->bus);
 141         int bus = dev->bus->number;
 142         int device = pci_ari_enabled(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(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(handle, prt->source, &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(handle, &buffer);
 215         if (ACPI_FAILURE(status)) {
 216                 kfree(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                                                  entry, entry_ptr))
 224                         break;
 225                 entry = (struct acpi_pci_routing_table *)
 226                     ((unsigned long)entry + entry->length);
 227         }
 228
 229         kfree(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(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 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);
 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(bridge, pin, &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(dev->irq) &&
 349             (acpi_isa_irq_to_gsi(dev->irq, &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,
 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(entry->link,
 427                                                          entry->index,
 428                                                          &triggering, &polarity,
 429                                                          &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(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(entry);
 450                 return 0;
 451         }
 452
 453         rc = acpi_register_gsi(&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(entry);
 458                 return rc;
 459         }
 460         dev->irq = rc;
 461         dev->irq_managed = 1;
 462
 463         if (link)
 464                 snprintf(link_desc, sizeof(link_desc), " -> 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(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(entry->link);
 501         else
 502                 gsi = entry->index;
 503
 504         kfree(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 }