linux/drivers/acpi/pci_irq.c
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   1/*
   2 *  pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
   3 *
   4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6 *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
   7 *  (c) Copyright 2008 Hewlett-Packard Development Company, L.P.
   8 *      Bjorn Helgaas <bjorn.helgaas@hp.com>
   9 *
  10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11 *
  12 *  This program is free software; you can redistribute it and/or modify
  13 *  it under the terms of the GNU General Public License as published by
  14 *  the Free Software Foundation; either version 2 of the License, or (at
  15 *  your option) any later version.
  16 *
  17 *  This program is distributed in the hope that it will be useful, but
  18 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20 *  General Public License for more details.
  21 *
  22 *  You should have received a copy of the GNU General Public License along
  23 *  with this program; if not, write to the Free Software Foundation, Inc.,
  24 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25 *
  26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27 */
  28
  29
  30#include <linux/dmi.h>
  31#include <linux/kernel.h>
  32#include <linux/module.h>
  33#include <linux/init.h>
  34#include <linux/types.h>
  35#include <linux/spinlock.h>
  36#include <linux/pm.h>
  37#include <linux/pci.h>
  38#include <linux/acpi.h>
  39#include <linux/slab.h>
  40#include <acpi/acpi_bus.h>
  41#include <acpi/acpi_drivers.h>
  42
  43#define PREFIX "ACPI: "
  44
  45#define _COMPONENT              ACPI_PCI_COMPONENT
  46ACPI_MODULE_NAME("pci_irq");
  47
  48struct acpi_prt_entry {
  49        struct list_head        list;
  50        struct acpi_pci_id      id;
  51        u8                      pin;
  52        acpi_handle             link;
  53        u32                     index;          /* GSI, or link _CRS index */
  54};
  55
  56static inline char pin_name(int pin)
  57{
  58        return 'A' + pin - 1;
  59}
  60
  61/* --------------------------------------------------------------------------
  62                         PCI IRQ Routing Table (PRT) Support
  63   -------------------------------------------------------------------------- */
  64
  65/* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
  66static const struct dmi_system_id medion_md9580[] = {
  67        {
  68                .ident = "Medion MD9580-F laptop",
  69                .matches = {
  70                        DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
  71                        DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
  72                },
  73        },
  74        { }
  75};
  76
  77/* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
  78static const struct dmi_system_id dell_optiplex[] = {
  79        {
  80                .ident = "Dell Optiplex GX1",
  81                .matches = {
  82                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
  83                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
  84                },
  85        },
  86        { }
  87};
  88
  89/* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
  90static const struct dmi_system_id hp_t5710[] = {
  91        {
  92                .ident = "HP t5710",
  93                .matches = {
  94                        DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  95                        DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
  96                        DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
  97                },
  98        },
  99        { }
 100};
 101
 102struct prt_quirk {
 103        const struct dmi_system_id *system;
 104        unsigned int            segment;
 105        unsigned int            bus;
 106        unsigned int            device;
 107        unsigned char           pin;
 108        const char              *source;        /* according to BIOS */
 109        const char              *actual_source;
 110};
 111
 112#define PCI_INTX_PIN(c)         (c - 'A' + 1)
 113
 114/*
 115 * These systems have incorrect _PRT entries.  The BIOS claims the PCI
 116 * interrupt at the listed segment/bus/device/pin is connected to the first
 117 * link device, but it is actually connected to the second.
 118 */
 119static const struct prt_quirk prt_quirks[] = {
 120        { medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
 121                "\\_SB_.PCI0.ISA_.LNKA",
 122                "\\_SB_.PCI0.ISA_.LNKB"},
 123        { dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
 124                "\\_SB_.LNKB",
 125                "\\_SB_.LNKA"},
 126        { hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
 127                "\\_SB_.PCI0.LNK1",
 128                "\\_SB_.PCI0.LNK3"},
 129};
 130
 131static void do_prt_fixups(struct acpi_prt_entry *entry,
 132                          struct acpi_pci_routing_table *prt)
 133{
 134        int i;
 135        const struct prt_quirk *quirk;
 136
 137        for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
 138                quirk = &prt_quirks[i];
 139
 140                /* All current quirks involve link devices, not GSIs */
 141                if (!prt->source)
 142                        continue;
 143
 144                if (dmi_check_system(quirk->system) &&
 145                    entry->id.segment == quirk->segment &&
 146                    entry->id.bus == quirk->bus &&
 147                    entry->id.device == quirk->device &&
 148                    entry->pin == quirk->pin &&
 149                    !strcmp(prt->source, quirk->source) &&
 150                    strlen(prt->source) >= strlen(quirk->actual_source)) {
 151                        printk(KERN_WARNING PREFIX "firmware reports "
 152                                "%04x:%02x:%02x PCI INT %c connected to %s; "
 153                                "changing to %s\n",
 154                                entry->id.segment, entry->id.bus,
 155                                entry->id.device, pin_name(entry->pin),
 156                                prt->source, quirk->actual_source);
 157                        strcpy(prt->source, quirk->actual_source);
 158                }
 159        }
 160}
 161
 162static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
 163                                  int pin, struct acpi_pci_routing_table *prt,
 164                                  struct acpi_prt_entry **entry_ptr)
 165{
 166        int segment = pci_domain_nr(dev->bus);
 167        int bus = dev->bus->number;
 168        int device = PCI_SLOT(dev->devfn);
 169        struct acpi_prt_entry *entry;
 170
 171        if (((prt->address >> 16) & 0xffff) != device ||
 172            prt->pin + 1 != pin)
 173                return -ENODEV;
 174
 175        entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
 176        if (!entry)
 177                return -ENOMEM;
 178
 179        /*
 180         * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
 181         * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
 182         * it here.
 183         */
 184        entry->id.segment = segment;
 185        entry->id.bus = bus;
 186        entry->id.device = (prt->address >> 16) & 0xFFFF;
 187        entry->pin = prt->pin + 1;
 188
 189        do_prt_fixups(entry, prt);
 190
 191        entry->index = prt->source_index;
 192
 193        /*
 194         * Type 1: Dynamic
 195         * ---------------
 196         * The 'source' field specifies the PCI interrupt link device used to
 197         * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
 198         * indicates which resource descriptor in the resource template (of
 199         * the link device) this interrupt is allocated from.
 200         * 
 201         * NOTE: Don't query the Link Device for IRQ information at this time
 202         *       because Link Device enumeration may not have occurred yet
 203         *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
 204         *       namespace).
 205         */
 206        if (prt->source[0])
 207                acpi_get_handle(handle, prt->source, &entry->link);
 208
 209        /*
 210         * Type 2: Static
 211         * --------------
 212         * The 'source' field is NULL, and the 'source_index' field specifies
 213         * the IRQ value, which is hardwired to specific interrupt inputs on
 214         * the interrupt controller.
 215         */
 216
 217        ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
 218                              "      %04x:%02x:%02x[%c] -> %s[%d]\n",
 219                              entry->id.segment, entry->id.bus,
 220                              entry->id.device, pin_name(entry->pin),
 221                              prt->source, entry->index));
 222
 223        *entry_ptr = entry;
 224
 225        return 0;
 226}
 227
 228static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
 229                          int pin, struct acpi_prt_entry **entry_ptr)
 230{
 231        acpi_status status;
 232        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 233        struct acpi_pci_routing_table *entry;
 234        acpi_handle handle = NULL;
 235
 236        if (dev->bus->bridge)
 237                handle = ACPI_HANDLE(dev->bus->bridge);
 238
 239        if (!handle)
 240                return -ENODEV;
 241
 242        /* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
 243        status = acpi_get_irq_routing_table(handle, &buffer);
 244        if (ACPI_FAILURE(status)) {
 245                kfree(buffer.pointer);
 246                return -ENODEV;
 247        }
 248
 249        entry = buffer.pointer;
 250        while (entry && (entry->length > 0)) {
 251                if (!acpi_pci_irq_check_entry(handle, dev, pin,
 252                                                 entry, entry_ptr))
 253                        break;
 254                entry = (struct acpi_pci_routing_table *)
 255                    ((unsigned long)entry + entry->length);
 256        }
 257
 258        kfree(buffer.pointer);
 259        return 0;
 260}
 261
 262/* --------------------------------------------------------------------------
 263                          PCI Interrupt Routing Support
 264   -------------------------------------------------------------------------- */
 265#ifdef CONFIG_X86_IO_APIC
 266extern int noioapicquirk;
 267extern int noioapicreroute;
 268
 269static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
 270{
 271        struct pci_bus *bus_it;
 272
 273        for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
 274                if (!bus_it->self)
 275                        return 0;
 276                if (bus_it->self->irq_reroute_variant)
 277                        return bus_it->self->irq_reroute_variant;
 278        }
 279        return 0;
 280}
 281
 282/*
 283 * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
 284 * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
 285 * during interrupt handling). When this INTx generation cannot be disabled,
 286 * we reroute these interrupts to their legacy equivalent to get rid of
 287 * spurious interrupts.
 288 */
 289static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
 290                                       struct acpi_prt_entry *entry)
 291{
 292        if (noioapicquirk || noioapicreroute) {
 293                return 0;
 294        } else {
 295                switch (bridge_has_boot_interrupt_variant(dev->bus)) {
 296                case 0:
 297                        /* no rerouting necessary */
 298                        return 0;
 299                case INTEL_IRQ_REROUTE_VARIANT:
 300                        /*
 301                         * Remap according to INTx routing table in 6700PXH
 302                         * specs, intel order number 302628-002, section
 303                         * 2.15.2. Other chipsets (80332, ...) have the same
 304                         * mapping and are handled here as well.
 305                         */
 306                        dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
 307                                 "IRQ %d\n", entry->index,
 308                                 (entry->index % 4) + 16);
 309                        entry->index = (entry->index % 4) + 16;
 310                        return 1;
 311                default:
 312                        dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
 313                                 "IRQ: unknown mapping\n", entry->index);
 314                        return -1;
 315                }
 316        }
 317}
 318#endif /* CONFIG_X86_IO_APIC */
 319
 320static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
 321{
 322        struct acpi_prt_entry *entry = NULL;
 323        struct pci_dev *bridge;
 324        u8 bridge_pin, orig_pin = pin;
 325        int ret;
 326
 327        ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
 328        if (!ret && entry) {
 329#ifdef CONFIG_X86_IO_APIC
 330                acpi_reroute_boot_interrupt(dev, entry);
 331#endif /* CONFIG_X86_IO_APIC */
 332                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
 333                                  pci_name(dev), pin_name(pin)));
 334                return entry;
 335        }
 336
 337        /*
 338         * Attempt to derive an IRQ for this device from a parent bridge's
 339         * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
 340         */
 341        bridge = dev->bus->self;
 342        while (bridge) {
 343                pin = pci_swizzle_interrupt_pin(dev, pin);
 344
 345                if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
 346                        /* PC card has the same IRQ as its cardbridge */
 347                        bridge_pin = bridge->pin;
 348                        if (!bridge_pin) {
 349                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 350                                                  "No interrupt pin configured for device %s\n",
 351                                                  pci_name(bridge)));
 352                                return NULL;
 353                        }
 354                        pin = bridge_pin;
 355                }
 356
 357                ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
 358                if (!ret && entry) {
 359                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 360                                         "Derived GSI for %s INT %c from %s\n",
 361                                         pci_name(dev), pin_name(orig_pin),
 362                                         pci_name(bridge)));
 363                        return entry;
 364                }
 365
 366                dev = bridge;
 367                bridge = dev->bus->self;
 368        }
 369
 370        dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
 371                 pin_name(orig_pin));
 372        return NULL;
 373}
 374
 375int acpi_pci_irq_enable(struct pci_dev *dev)
 376{
 377        struct acpi_prt_entry *entry;
 378        int gsi;
 379        u8 pin;
 380        int triggering = ACPI_LEVEL_SENSITIVE;
 381        int polarity = ACPI_ACTIVE_LOW;
 382        char *link = NULL;
 383        char link_desc[16];
 384        int rc;
 385
 386        pin = dev->pin;
 387        if (!pin) {
 388                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 389                                  "No interrupt pin configured for device %s\n",
 390                                  pci_name(dev)));
 391                return 0;
 392        }
 393
 394        entry = acpi_pci_irq_lookup(dev, pin);
 395        if (!entry) {
 396                /*
 397                 * IDE legacy mode controller IRQs are magic. Why do compat
 398                 * extensions always make such a nasty mess.
 399                 */
 400                if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
 401                                (dev->class & 0x05) == 0)
 402                        return 0;
 403        }
 404
 405        if (entry) {
 406                if (entry->link)
 407                        gsi = acpi_pci_link_allocate_irq(entry->link,
 408                                                         entry->index,
 409                                                         &triggering, &polarity,
 410                                                         &link);
 411                else
 412                        gsi = entry->index;
 413        } else
 414                gsi = -1;
 415
 416        /*
 417         * No IRQ known to the ACPI subsystem - maybe the BIOS / 
 418         * driver reported one, then use it. Exit in any case.
 419         */
 420        if (gsi < 0) {
 421                u32 dev_gsi;
 422                /* Interrupt Line values above 0xF are forbidden */
 423                if (dev->irq > 0 && (dev->irq <= 0xF) &&
 424                    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
 425                        dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
 426                                 pin_name(pin), dev->irq);
 427                        acpi_register_gsi(&dev->dev, dev_gsi,
 428                                          ACPI_LEVEL_SENSITIVE,
 429                                          ACPI_ACTIVE_LOW);
 430                } else {
 431                        dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
 432                                 pin_name(pin));
 433                }
 434
 435                return 0;
 436        }
 437
 438        rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
 439        if (rc < 0) {
 440                dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
 441                         pin_name(pin));
 442                kfree(entry);
 443                return rc;
 444        }
 445        dev->irq = rc;
 446
 447        if (link)
 448                snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
 449        else
 450                link_desc[0] = '\0';
 451
 452        dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
 453                pin_name(pin), link_desc, gsi,
 454                (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
 455                (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
 456
 457        kfree(entry);
 458        return 0;
 459}
 460
 461void acpi_pci_irq_disable(struct pci_dev *dev)
 462{
 463        struct acpi_prt_entry *entry;
 464        int gsi;
 465        u8 pin;
 466
 467        pin = dev->pin;
 468        if (!pin)
 469                return;
 470
 471        entry = acpi_pci_irq_lookup(dev, pin);
 472        if (!entry)
 473                return;
 474
 475        if (entry->link)
 476                gsi = acpi_pci_link_free_irq(entry->link);
 477        else
 478                gsi = entry->index;
 479
 480        kfree(entry);
 481
 482        /*
 483         * TBD: It might be worth clearing dev->irq by magic constant
 484         * (e.g. PCI_UNDEFINED_IRQ).
 485         */
 486
 487        dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
 488        acpi_unregister_gsi(gsi);
 489}
 490
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