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 LIST_HEAD(acpi_prt_list);
  57static DEFINE_SPINLOCK(acpi_prt_lock);
  58
  59static inline char pin_name(int pin)
  60{
  61        return 'A' + pin - 1;
  62}
  63
  64/* --------------------------------------------------------------------------
  65                         PCI IRQ Routing Table (PRT) Support
  66   -------------------------------------------------------------------------- */
  67
  68static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
  69                                                          int pin)
  70{
  71        struct acpi_prt_entry *entry;
  72        int segment = pci_domain_nr(dev->bus);
  73        int bus = dev->bus->number;
  74        int device = PCI_SLOT(dev->devfn);
  75
  76        spin_lock(&acpi_prt_lock);
  77        list_for_each_entry(entry, &acpi_prt_list, list) {
  78                if ((segment == entry->id.segment)
  79                    && (bus == entry->id.bus)
  80                    && (device == entry->id.device)
  81                    && (pin == entry->pin)) {
  82                        spin_unlock(&acpi_prt_lock);
  83                        return entry;
  84                }
  85        }
  86        spin_unlock(&acpi_prt_lock);
  87        return NULL;
  88}
  89
  90/* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
  91static const struct dmi_system_id medion_md9580[] = {
  92        {
  93                .ident = "Medion MD9580-F laptop",
  94                .matches = {
  95                        DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
  96                        DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
  97                },
  98        },
  99        { }
 100};
 101
 102/* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
 103static const struct dmi_system_id dell_optiplex[] = {
 104        {
 105                .ident = "Dell Optiplex GX1",
 106                .matches = {
 107                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 108                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
 109                },
 110        },
 111        { }
 112};
 113
 114/* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
 115static const struct dmi_system_id hp_t5710[] = {
 116        {
 117                .ident = "HP t5710",
 118                .matches = {
 119                        DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 120                        DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
 121                        DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
 122                },
 123        },
 124        { }
 125};
 126
 127struct prt_quirk {
 128        const struct dmi_system_id *system;
 129        unsigned int            segment;
 130        unsigned int            bus;
 131        unsigned int            device;
 132        unsigned char           pin;
 133        const char              *source;        /* according to BIOS */
 134        const char              *actual_source;
 135};
 136
 137#define PCI_INTX_PIN(c)         (c - 'A' + 1)
 138
 139/*
 140 * These systems have incorrect _PRT entries.  The BIOS claims the PCI
 141 * interrupt at the listed segment/bus/device/pin is connected to the first
 142 * link device, but it is actually connected to the second.
 143 */
 144static const struct prt_quirk prt_quirks[] = {
 145        { medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
 146                "\\_SB_.PCI0.ISA_.LNKA",
 147                "\\_SB_.PCI0.ISA_.LNKB"},
 148        { dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
 149                "\\_SB_.LNKB",
 150                "\\_SB_.LNKA"},
 151        { hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
 152                "\\_SB_.PCI0.LNK1",
 153                "\\_SB_.PCI0.LNK3"},
 154};
 155
 156static void do_prt_fixups(struct acpi_prt_entry *entry,
 157                          struct acpi_pci_routing_table *prt)
 158{
 159        int i;
 160        const struct prt_quirk *quirk;
 161
 162        for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
 163                quirk = &prt_quirks[i];
 164
 165                /* All current quirks involve link devices, not GSIs */
 166                if (!prt->source)
 167                        continue;
 168
 169                if (dmi_check_system(quirk->system) &&
 170                    entry->id.segment == quirk->segment &&
 171                    entry->id.bus == quirk->bus &&
 172                    entry->id.device == quirk->device &&
 173                    entry->pin == quirk->pin &&
 174                    !strcmp(prt->source, quirk->source) &&
 175                    strlen(prt->source) >= strlen(quirk->actual_source)) {
 176                        printk(KERN_WARNING PREFIX "firmware reports "
 177                                "%04x:%02x:%02x PCI INT %c connected to %s; "
 178                                "changing to %s\n",
 179                                entry->id.segment, entry->id.bus,
 180                                entry->id.device, pin_name(entry->pin),
 181                                prt->source, quirk->actual_source);
 182                        strcpy(prt->source, quirk->actual_source);
 183                }
 184        }
 185}
 186
 187static int acpi_pci_irq_add_entry(acpi_handle handle, int segment, int bus,
 188                                  struct acpi_pci_routing_table *prt)
 189{
 190        struct acpi_prt_entry *entry;
 191
 192        entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
 193        if (!entry)
 194                return -ENOMEM;
 195
 196        /*
 197         * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
 198         * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
 199         * it here.
 200         */
 201        entry->id.segment = segment;
 202        entry->id.bus = bus;
 203        entry->id.device = (prt->address >> 16) & 0xFFFF;
 204        entry->pin = prt->pin + 1;
 205
 206        do_prt_fixups(entry, prt);
 207
 208        entry->index = prt->source_index;
 209
 210        /*
 211         * Type 1: Dynamic
 212         * ---------------
 213         * The 'source' field specifies the PCI interrupt link device used to
 214         * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
 215         * indicates which resource descriptor in the resource template (of
 216         * the link device) this interrupt is allocated from.
 217         * 
 218         * NOTE: Don't query the Link Device for IRQ information at this time
 219         *       because Link Device enumeration may not have occurred yet
 220         *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
 221         *       namespace).
 222         */
 223        if (prt->source[0])
 224                acpi_get_handle(handle, prt->source, &entry->link);
 225
 226        /*
 227         * Type 2: Static
 228         * --------------
 229         * The 'source' field is NULL, and the 'source_index' field specifies
 230         * the IRQ value, which is hardwired to specific interrupt inputs on
 231         * the interrupt controller.
 232         */
 233
 234        ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
 235                              "      %04x:%02x:%02x[%c] -> %s[%d]\n",
 236                              entry->id.segment, entry->id.bus,
 237                              entry->id.device, pin_name(entry->pin),
 238                              prt->source, entry->index));
 239
 240        spin_lock(&acpi_prt_lock);
 241        list_add_tail(&entry->list, &acpi_prt_list);
 242        spin_unlock(&acpi_prt_lock);
 243
 244        return 0;
 245}
 246
 247int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
 248{
 249        acpi_status status;
 250        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 251        struct acpi_pci_routing_table *entry;
 252
 253        /* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
 254        status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 255        if (ACPI_FAILURE(status))
 256                return -ENODEV;
 257
 258        printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
 259               (char *) buffer.pointer);
 260
 261        kfree(buffer.pointer);
 262
 263        buffer.length = ACPI_ALLOCATE_BUFFER;
 264        buffer.pointer = NULL;
 265
 266        status = acpi_get_irq_routing_table(handle, &buffer);
 267        if (ACPI_FAILURE(status)) {
 268                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
 269                                acpi_format_exception(status)));
 270                kfree(buffer.pointer);
 271                return -ENODEV;
 272        }
 273
 274        entry = buffer.pointer;
 275        while (entry && (entry->length > 0)) {
 276                acpi_pci_irq_add_entry(handle, segment, bus, entry);
 277                entry = (struct acpi_pci_routing_table *)
 278                    ((unsigned long)entry + entry->length);
 279        }
 280
 281        kfree(buffer.pointer);
 282        return 0;
 283}
 284
 285void acpi_pci_irq_del_prt(int segment, int bus)
 286{
 287        struct acpi_prt_entry *entry, *tmp;
 288
 289        printk(KERN_DEBUG
 290               "ACPI: Delete PCI Interrupt Routing Table for %04x:%02x\n",
 291               segment, bus);
 292        spin_lock(&acpi_prt_lock);
 293        list_for_each_entry_safe(entry, tmp, &acpi_prt_list, list) {
 294                if (segment == entry->id.segment && bus == entry->id.bus) {
 295                        list_del(&entry->list);
 296                        kfree(entry);
 297                }
 298        }
 299        spin_unlock(&acpi_prt_lock);
 300}
 301
 302/* --------------------------------------------------------------------------
 303                          PCI Interrupt Routing Support
 304   -------------------------------------------------------------------------- */
 305#ifdef CONFIG_X86_IO_APIC
 306extern int noioapicquirk;
 307extern int noioapicreroute;
 308
 309static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
 310{
 311        struct pci_bus *bus_it;
 312
 313        for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
 314                if (!bus_it->self)
 315                        return 0;
 316                if (bus_it->self->irq_reroute_variant)
 317                        return bus_it->self->irq_reroute_variant;
 318        }
 319        return 0;
 320}
 321
 322/*
 323 * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
 324 * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
 325 * during interrupt handling). When this INTx generation cannot be disabled,
 326 * we reroute these interrupts to their legacy equivalent to get rid of
 327 * spurious interrupts.
 328 */
 329static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
 330                                       struct acpi_prt_entry *entry)
 331{
 332        if (noioapicquirk || noioapicreroute) {
 333                return 0;
 334        } else {
 335                switch (bridge_has_boot_interrupt_variant(dev->bus)) {
 336                case 0:
 337                        /* no rerouting necessary */
 338                        return 0;
 339                case INTEL_IRQ_REROUTE_VARIANT:
 340                        /*
 341                         * Remap according to INTx routing table in 6700PXH
 342                         * specs, intel order number 302628-002, section
 343                         * 2.15.2. Other chipsets (80332, ...) have the same
 344                         * mapping and are handled here as well.
 345                         */
 346                        dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
 347                                 "IRQ %d\n", entry->index,
 348                                 (entry->index % 4) + 16);
 349                        entry->index = (entry->index % 4) + 16;
 350                        return 1;
 351                default:
 352                        dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
 353                                 "IRQ: unknown mapping\n", entry->index);
 354                        return -1;
 355                }
 356        }
 357}
 358#endif /* CONFIG_X86_IO_APIC */
 359
 360static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
 361{
 362        struct acpi_prt_entry *entry;
 363        struct pci_dev *bridge;
 364        u8 bridge_pin, orig_pin = pin;
 365
 366        entry = acpi_pci_irq_find_prt_entry(dev, pin);
 367        if (entry) {
 368#ifdef CONFIG_X86_IO_APIC
 369                acpi_reroute_boot_interrupt(dev, entry);
 370#endif /* CONFIG_X86_IO_APIC */
 371                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
 372                                  pci_name(dev), pin_name(pin)));
 373                return entry;
 374        }
 375
 376        /* 
 377         * Attempt to derive an IRQ for this device from a parent bridge's
 378         * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
 379         */
 380        bridge = dev->bus->self;
 381        while (bridge) {
 382                pin = pci_swizzle_interrupt_pin(dev, pin);
 383
 384                if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
 385                        /* PC card has the same IRQ as its cardbridge */
 386                        bridge_pin = bridge->pin;
 387                        if (!bridge_pin) {
 388                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 389                                                  "No interrupt pin configured for device %s\n",
 390                                                  pci_name(bridge)));
 391                                return NULL;
 392                        }
 393                        pin = bridge_pin;
 394                }
 395
 396                entry = acpi_pci_irq_find_prt_entry(bridge, pin);
 397                if (entry) {
 398                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 399                                         "Derived GSI for %s INT %c from %s\n",
 400                                         pci_name(dev), pin_name(orig_pin),
 401                                         pci_name(bridge)));
 402                        return entry;
 403                }
 404
 405                dev = bridge;
 406                bridge = dev->bus->self;
 407        }
 408
 409        dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
 410                 pin_name(orig_pin));
 411        return NULL;
 412}
 413
 414int acpi_pci_irq_enable(struct pci_dev *dev)
 415{
 416        struct acpi_prt_entry *entry;
 417        int gsi;
 418        u8 pin;
 419        int triggering = ACPI_LEVEL_SENSITIVE;
 420        int polarity = ACPI_ACTIVE_LOW;
 421        char *link = NULL;
 422        char link_desc[16];
 423        int rc;
 424
 425        pin = dev->pin;
 426        if (!pin) {
 427                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 428                                  "No interrupt pin configured for device %s\n",
 429                                  pci_name(dev)));
 430                return 0;
 431        }
 432
 433        entry = acpi_pci_irq_lookup(dev, pin);
 434        if (!entry) {
 435                /*
 436                 * IDE legacy mode controller IRQs are magic. Why do compat
 437                 * extensions always make such a nasty mess.
 438                 */
 439                if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
 440                                (dev->class & 0x05) == 0)
 441                        return 0;
 442        }
 443
 444        if (entry) {
 445                if (entry->link)
 446                        gsi = acpi_pci_link_allocate_irq(entry->link,
 447                                                         entry->index,
 448                                                         &triggering, &polarity,
 449                                                         &link);
 450                else
 451                        gsi = entry->index;
 452        } else
 453                gsi = -1;
 454
 455        /*
 456         * No IRQ known to the ACPI subsystem - maybe the BIOS / 
 457         * driver reported one, then use it. Exit in any case.
 458         */
 459        if (gsi < 0) {
 460                u32 dev_gsi;
 461                /* Interrupt Line values above 0xF are forbidden */
 462                if (dev->irq > 0 && (dev->irq <= 0xF) &&
 463                    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
 464                        dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
 465                                 pin_name(pin), dev->irq);
 466                        acpi_register_gsi(&dev->dev, dev_gsi,
 467                                          ACPI_LEVEL_SENSITIVE,
 468                                          ACPI_ACTIVE_LOW);
 469                } else {
 470                        dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
 471                                 pin_name(pin));
 472                }
 473                return 0;
 474        }
 475
 476        rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
 477        if (rc < 0) {
 478                dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
 479                         pin_name(pin));
 480                return rc;
 481        }
 482        dev->irq = rc;
 483
 484        if (link)
 485                snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
 486        else
 487                link_desc[0] = '\0';
 488
 489        dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
 490                pin_name(pin), link_desc, gsi,
 491                (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
 492                (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
 493
 494        return 0;
 495}
 496
 497void acpi_pci_irq_disable(struct pci_dev *dev)
 498{
 499        struct acpi_prt_entry *entry;
 500        int gsi;
 501        u8 pin;
 502
 503        pin = dev->pin;
 504        if (!pin)
 505                return;
 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        /*
 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        acpi_unregister_gsi(gsi);
 523}
 524
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