linux/drivers/acpi/pci_link.c
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   1/*
   2 *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
   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 *
   8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License as published by
  12 *  the Free Software Foundation; either version 2 of the License, or (at
  13 *  your option) any later version.
  14 *
  15 *  This program is distributed in the hope that it will be useful, but
  16 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 *  General Public License for more details.
  19 *
  20 *  You should have received a copy of the GNU General Public License along
  21 *  with this program; if not, write to the Free Software Foundation, Inc.,
  22 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23 *
  24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25 *
  26 * TBD: 
  27 *      1. Support more than one IRQ resource entry per link device (index).
  28 *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  29 *         for IRQ management (e.g. start()->_SRS).
  30 */
  31
  32#include <linux/syscore_ops.h>
  33#include <linux/kernel.h>
  34#include <linux/module.h>
  35#include <linux/init.h>
  36#include <linux/types.h>
  37#include <linux/spinlock.h>
  38#include <linux/pm.h>
  39#include <linux/pci.h>
  40#include <linux/mutex.h>
  41#include <linux/slab.h>
  42
  43#include <acpi/acpi_bus.h>
  44#include <acpi/acpi_drivers.h>
  45
  46#define PREFIX "ACPI: "
  47
  48#define _COMPONENT                      ACPI_PCI_COMPONENT
  49ACPI_MODULE_NAME("pci_link");
  50#define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  51#define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  52#define ACPI_PCI_LINK_FILE_INFO         "info"
  53#define ACPI_PCI_LINK_FILE_STATUS       "state"
  54#define ACPI_PCI_LINK_MAX_POSSIBLE      16
  55
  56static int acpi_pci_link_add(struct acpi_device *device);
  57static int acpi_pci_link_remove(struct acpi_device *device, int type);
  58
  59static const struct acpi_device_id link_device_ids[] = {
  60        {"PNP0C0F", 0},
  61        {"", 0},
  62};
  63MODULE_DEVICE_TABLE(acpi, link_device_ids);
  64
  65static struct acpi_driver acpi_pci_link_driver = {
  66        .name = "pci_link",
  67        .class = ACPI_PCI_LINK_CLASS,
  68        .ids = link_device_ids,
  69        .ops = {
  70                .add = acpi_pci_link_add,
  71                .remove = acpi_pci_link_remove,
  72        },
  73};
  74
  75/*
  76 * If a link is initialized, we never change its active and initialized
  77 * later even the link is disable. Instead, we just repick the active irq
  78 */
  79struct acpi_pci_link_irq {
  80        u8 active;              /* Current IRQ */
  81        u8 triggering;          /* All IRQs */
  82        u8 polarity;            /* All IRQs */
  83        u8 resource_type;
  84        u8 possible_count;
  85        u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  86        u8 initialized:1;
  87        u8 reserved:7;
  88};
  89
  90struct acpi_pci_link {
  91        struct list_head                list;
  92        struct acpi_device              *device;
  93        struct acpi_pci_link_irq        irq;
  94        int                             refcnt;
  95};
  96
  97static LIST_HEAD(acpi_link_list);
  98static DEFINE_MUTEX(acpi_link_lock);
  99
 100/* --------------------------------------------------------------------------
 101                            PCI Link Device Management
 102   -------------------------------------------------------------------------- */
 103
 104/*
 105 * set context (link) possible list from resource list
 106 */
 107static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
 108                                                void *context)
 109{
 110        struct acpi_pci_link *link = context;
 111        u32 i;
 112
 113        switch (resource->type) {
 114        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 115        case ACPI_RESOURCE_TYPE_END_TAG:
 116                return AE_OK;
 117        case ACPI_RESOURCE_TYPE_IRQ:
 118                {
 119                        struct acpi_resource_irq *p = &resource->data.irq;
 120                        if (!p || !p->interrupt_count) {
 121                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 122                                                  "Blank _PRS IRQ resource\n"));
 123                                return AE_OK;
 124                        }
 125                        for (i = 0;
 126                             (i < p->interrupt_count
 127                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 128                                if (!p->interrupts[i]) {
 129                                        printk(KERN_WARNING PREFIX
 130                                               "Invalid _PRS IRQ %d\n",
 131                                               p->interrupts[i]);
 132                                        continue;
 133                                }
 134                                link->irq.possible[i] = p->interrupts[i];
 135                                link->irq.possible_count++;
 136                        }
 137                        link->irq.triggering = p->triggering;
 138                        link->irq.polarity = p->polarity;
 139                        link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 140                        break;
 141                }
 142        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 143                {
 144                        struct acpi_resource_extended_irq *p =
 145                            &resource->data.extended_irq;
 146                        if (!p || !p->interrupt_count) {
 147                                printk(KERN_WARNING PREFIX
 148                                              "Blank _PRS EXT IRQ resource\n");
 149                                return AE_OK;
 150                        }
 151                        for (i = 0;
 152                             (i < p->interrupt_count
 153                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 154                                if (!p->interrupts[i]) {
 155                                        printk(KERN_WARNING PREFIX
 156                                               "Invalid _PRS IRQ %d\n",
 157                                               p->interrupts[i]);
 158                                        continue;
 159                                }
 160                                link->irq.possible[i] = p->interrupts[i];
 161                                link->irq.possible_count++;
 162                        }
 163                        link->irq.triggering = p->triggering;
 164                        link->irq.polarity = p->polarity;
 165                        link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 166                        break;
 167                }
 168        default:
 169                printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 170                       resource->type);
 171                return AE_OK;
 172        }
 173
 174        return AE_CTRL_TERMINATE;
 175}
 176
 177static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 178{
 179        acpi_status status;
 180
 181        status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 182                                     acpi_pci_link_check_possible, link);
 183        if (ACPI_FAILURE(status)) {
 184                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 185                return -ENODEV;
 186        }
 187
 188        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 189                          "Found %d possible IRQs\n",
 190                          link->irq.possible_count));
 191
 192        return 0;
 193}
 194
 195static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 196                                               void *context)
 197{
 198        int *irq = context;
 199
 200        switch (resource->type) {
 201        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 202        case ACPI_RESOURCE_TYPE_END_TAG:
 203                return AE_OK;
 204        case ACPI_RESOURCE_TYPE_IRQ:
 205                {
 206                        struct acpi_resource_irq *p = &resource->data.irq;
 207                        if (!p || !p->interrupt_count) {
 208                                /*
 209                                 * IRQ descriptors may have no IRQ# bits set,
 210                                 * particularly those those w/ _STA disabled
 211                                 */
 212                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 213                                                  "Blank _CRS IRQ resource\n"));
 214                                return AE_OK;
 215                        }
 216                        *irq = p->interrupts[0];
 217                        break;
 218                }
 219        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 220                {
 221                        struct acpi_resource_extended_irq *p =
 222                            &resource->data.extended_irq;
 223                        if (!p || !p->interrupt_count) {
 224                                /*
 225                                 * extended IRQ descriptors must
 226                                 * return at least 1 IRQ
 227                                 */
 228                                printk(KERN_WARNING PREFIX
 229                                              "Blank _CRS EXT IRQ resource\n");
 230                                return AE_OK;
 231                        }
 232                        *irq = p->interrupts[0];
 233                        break;
 234                }
 235                break;
 236        default:
 237                printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 238                       resource->type);
 239                return AE_OK;
 240        }
 241
 242        return AE_CTRL_TERMINATE;
 243}
 244
 245/*
 246 * Run _CRS and set link->irq.active
 247 *
 248 * return value:
 249 * 0 - success
 250 * !0 - failure
 251 */
 252static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 253{
 254        int result = 0;
 255        acpi_status status;
 256        int irq = 0;
 257
 258        link->irq.active = 0;
 259
 260        /* in practice, status disabled is meaningless, ignore it */
 261        if (acpi_strict) {
 262                /* Query _STA, set link->device->status */
 263                result = acpi_bus_get_status(link->device);
 264                if (result) {
 265                        printk(KERN_ERR PREFIX "Unable to read status\n");
 266                        goto end;
 267                }
 268
 269                if (!link->device->status.enabled) {
 270                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 271                        return 0;
 272                }
 273        }
 274
 275        /* 
 276         * Query and parse _CRS to get the current IRQ assignment. 
 277         */
 278
 279        status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 280                                     acpi_pci_link_check_current, &irq);
 281        if (ACPI_FAILURE(status)) {
 282                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 283                result = -ENODEV;
 284                goto end;
 285        }
 286
 287        if (acpi_strict && !irq) {
 288                printk(KERN_ERR PREFIX "_CRS returned 0\n");
 289                result = -ENODEV;
 290        }
 291
 292        link->irq.active = irq;
 293
 294        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 295
 296      end:
 297        return result;
 298}
 299
 300static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 301{
 302        int result;
 303        acpi_status status;
 304        struct {
 305                struct acpi_resource res;
 306                struct acpi_resource end;
 307        } *resource;
 308        struct acpi_buffer buffer = { 0, NULL };
 309
 310        if (!irq)
 311                return -EINVAL;
 312
 313        resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 314        if (!resource)
 315                return -ENOMEM;
 316
 317        buffer.length = sizeof(*resource) + 1;
 318        buffer.pointer = resource;
 319
 320        switch (link->irq.resource_type) {
 321        case ACPI_RESOURCE_TYPE_IRQ:
 322                resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 323                resource->res.length = sizeof(struct acpi_resource);
 324                resource->res.data.irq.triggering = link->irq.triggering;
 325                resource->res.data.irq.polarity =
 326                    link->irq.polarity;
 327                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 328                        resource->res.data.irq.sharable =
 329                            ACPI_EXCLUSIVE;
 330                else
 331                        resource->res.data.irq.sharable = ACPI_SHARED;
 332                resource->res.data.irq.interrupt_count = 1;
 333                resource->res.data.irq.interrupts[0] = irq;
 334                break;
 335
 336        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 337                resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 338                resource->res.length = sizeof(struct acpi_resource);
 339                resource->res.data.extended_irq.producer_consumer =
 340                    ACPI_CONSUMER;
 341                resource->res.data.extended_irq.triggering =
 342                    link->irq.triggering;
 343                resource->res.data.extended_irq.polarity =
 344                    link->irq.polarity;
 345                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 346                        resource->res.data.irq.sharable =
 347                            ACPI_EXCLUSIVE;
 348                else
 349                        resource->res.data.irq.sharable = ACPI_SHARED;
 350                resource->res.data.extended_irq.interrupt_count = 1;
 351                resource->res.data.extended_irq.interrupts[0] = irq;
 352                /* ignore resource_source, it's optional */
 353                break;
 354        default:
 355                printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 356                result = -EINVAL;
 357                goto end;
 358
 359        }
 360        resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 361
 362        /* Attempt to set the resource */
 363        status = acpi_set_current_resources(link->device->handle, &buffer);
 364
 365        /* check for total failure */
 366        if (ACPI_FAILURE(status)) {
 367                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 368                result = -ENODEV;
 369                goto end;
 370        }
 371
 372        /* Query _STA, set device->status */
 373        result = acpi_bus_get_status(link->device);
 374        if (result) {
 375                printk(KERN_ERR PREFIX "Unable to read status\n");
 376                goto end;
 377        }
 378        if (!link->device->status.enabled) {
 379                printk(KERN_WARNING PREFIX
 380                              "%s [%s] disabled and referenced, BIOS bug\n",
 381                              acpi_device_name(link->device),
 382                              acpi_device_bid(link->device));
 383        }
 384
 385        /* Query _CRS, set link->irq.active */
 386        result = acpi_pci_link_get_current(link);
 387        if (result) {
 388                goto end;
 389        }
 390
 391        /*
 392         * Is current setting not what we set?
 393         * set link->irq.active
 394         */
 395        if (link->irq.active != irq) {
 396                /*
 397                 * policy: when _CRS doesn't return what we just _SRS
 398                 * assume _SRS worked and override _CRS value.
 399                 */
 400                printk(KERN_WARNING PREFIX
 401                              "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 402                              acpi_device_name(link->device),
 403                              acpi_device_bid(link->device), link->irq.active, irq);
 404                link->irq.active = irq;
 405        }
 406
 407        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 408
 409      end:
 410        kfree(resource);
 411        return result;
 412}
 413
 414/* --------------------------------------------------------------------------
 415                            PCI Link IRQ Management
 416   -------------------------------------------------------------------------- */
 417
 418/*
 419 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 420 * Link Devices to move the PIRQs around to minimize sharing.
 421 * 
 422 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 423 * that the BIOS has already set to active.  This is necessary because
 424 * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 425 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 426 * even if acpi_irq_nobalance is set.
 427 *
 428 * A tables of penalties avoids directing PCI interrupts to well known
 429 * ISA IRQs. Boot params are available to over-ride the default table:
 430 *
 431 * List interrupts that are free for PCI use.
 432 * acpi_irq_pci=n[,m]
 433 *
 434 * List interrupts that should not be used for PCI:
 435 * acpi_irq_isa=n[,m]
 436 *
 437 * Note that PCI IRQ routers have a list of possible IRQs,
 438 * which may not include the IRQs this table says are available.
 439 * 
 440 * Since this heuristic can't tell the difference between a link
 441 * that no device will attach to, vs. a link which may be shared
 442 * by multiple active devices -- it is not optimal.
 443 *
 444 * If interrupt performance is that important, get an IO-APIC system
 445 * with a pin dedicated to each device.  Or for that matter, an MSI
 446 * enabled system.
 447 */
 448
 449#define ACPI_MAX_IRQS           256
 450#define ACPI_MAX_ISA_IRQ        16
 451
 452#define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 453#define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 454#define PIRQ_PENALTY_PCI_USING          (16*16*16)
 455#define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 456#define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 457#define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 458
 459static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 460        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 461        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 462        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 463        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 464        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 465        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 466        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 467        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 468        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 469        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 470        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 471        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 472        PIRQ_PENALTY_ISA_USED,          /* IRQ12 mouse */
 473        PIRQ_PENALTY_ISA_USED,          /* IRQ13 fpe, sometimes */
 474        PIRQ_PENALTY_ISA_USED,          /* IRQ14 ide0 */
 475        PIRQ_PENALTY_ISA_USED,          /* IRQ15 ide1 */
 476        /* >IRQ15 */
 477};
 478
 479int __init acpi_irq_penalty_init(void)
 480{
 481        struct acpi_pci_link *link;
 482        int i;
 483
 484        /*
 485         * Update penalties to facilitate IRQ balancing.
 486         */
 487        list_for_each_entry(link, &acpi_link_list, list) {
 488
 489                /*
 490                 * reflect the possible and active irqs in the penalty table --
 491                 * useful for breaking ties.
 492                 */
 493                if (link->irq.possible_count) {
 494                        int penalty =
 495                            PIRQ_PENALTY_PCI_POSSIBLE /
 496                            link->irq.possible_count;
 497
 498                        for (i = 0; i < link->irq.possible_count; i++) {
 499                                if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 500                                        acpi_irq_penalty[link->irq.
 501                                                         possible[i]] +=
 502                                            penalty;
 503                        }
 504
 505                } else if (link->irq.active) {
 506                        acpi_irq_penalty[link->irq.active] +=
 507                            PIRQ_PENALTY_PCI_POSSIBLE;
 508                }
 509        }
 510        /* Add a penalty for the SCI */
 511        acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
 512        return 0;
 513}
 514
 515static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 516
 517static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 518{
 519        int irq;
 520        int i;
 521
 522        if (link->irq.initialized) {
 523                if (link->refcnt == 0)
 524                        /* This means the link is disabled but initialized */
 525                        acpi_pci_link_set(link, link->irq.active);
 526                return 0;
 527        }
 528
 529        /*
 530         * search for active IRQ in list of possible IRQs.
 531         */
 532        for (i = 0; i < link->irq.possible_count; ++i) {
 533                if (link->irq.active == link->irq.possible[i])
 534                        break;
 535        }
 536        /*
 537         * forget active IRQ that is not in possible list
 538         */
 539        if (i == link->irq.possible_count) {
 540                if (acpi_strict)
 541                        printk(KERN_WARNING PREFIX "_CRS %d not found"
 542                                      " in _PRS\n", link->irq.active);
 543                link->irq.active = 0;
 544        }
 545
 546        /*
 547         * if active found, use it; else pick entry from end of possible list.
 548         */
 549        if (link->irq.active)
 550                irq = link->irq.active;
 551        else
 552                irq = link->irq.possible[link->irq.possible_count - 1];
 553
 554        if (acpi_irq_balance || !link->irq.active) {
 555                /*
 556                 * Select the best IRQ.  This is done in reverse to promote
 557                 * the use of IRQs 9, 10, 11, and >15.
 558                 */
 559                for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 560                        if (acpi_irq_penalty[irq] >
 561                            acpi_irq_penalty[link->irq.possible[i]])
 562                                irq = link->irq.possible[i];
 563                }
 564        }
 565
 566        /* Attempt to enable the link device at this IRQ. */
 567        if (acpi_pci_link_set(link, irq)) {
 568                printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 569                            "Try pci=noacpi or acpi=off\n",
 570                            acpi_device_name(link->device),
 571                            acpi_device_bid(link->device));
 572                return -ENODEV;
 573        } else {
 574                acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 575                printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
 576                       acpi_device_name(link->device),
 577                       acpi_device_bid(link->device), link->irq.active);
 578        }
 579
 580        link->irq.initialized = 1;
 581        return 0;
 582}
 583
 584/*
 585 * acpi_pci_link_allocate_irq
 586 * success: return IRQ >= 0
 587 * failure: return -1
 588 */
 589int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 590                               int *polarity, char **name)
 591{
 592        int result;
 593        struct acpi_device *device;
 594        struct acpi_pci_link *link;
 595
 596        result = acpi_bus_get_device(handle, &device);
 597        if (result) {
 598                printk(KERN_ERR PREFIX "Invalid link device\n");
 599                return -1;
 600        }
 601
 602        link = acpi_driver_data(device);
 603        if (!link) {
 604                printk(KERN_ERR PREFIX "Invalid link context\n");
 605                return -1;
 606        }
 607
 608        /* TBD: Support multiple index (IRQ) entries per Link Device */
 609        if (index) {
 610                printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 611                return -1;
 612        }
 613
 614        mutex_lock(&acpi_link_lock);
 615        if (acpi_pci_link_allocate(link)) {
 616                mutex_unlock(&acpi_link_lock);
 617                return -1;
 618        }
 619
 620        if (!link->irq.active) {
 621                mutex_unlock(&acpi_link_lock);
 622                printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 623                return -1;
 624        }
 625        link->refcnt++;
 626        mutex_unlock(&acpi_link_lock);
 627
 628        if (triggering)
 629                *triggering = link->irq.triggering;
 630        if (polarity)
 631                *polarity = link->irq.polarity;
 632        if (name)
 633                *name = acpi_device_bid(link->device);
 634        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 635                          "Link %s is referenced\n",
 636                          acpi_device_bid(link->device)));
 637        return (link->irq.active);
 638}
 639
 640/*
 641 * We don't change link's irq information here.  After it is reenabled, we
 642 * continue use the info
 643 */
 644int acpi_pci_link_free_irq(acpi_handle handle)
 645{
 646        struct acpi_device *device;
 647        struct acpi_pci_link *link;
 648        acpi_status result;
 649
 650        result = acpi_bus_get_device(handle, &device);
 651        if (result) {
 652                printk(KERN_ERR PREFIX "Invalid link device\n");
 653                return -1;
 654        }
 655
 656        link = acpi_driver_data(device);
 657        if (!link) {
 658                printk(KERN_ERR PREFIX "Invalid link context\n");
 659                return -1;
 660        }
 661
 662        mutex_lock(&acpi_link_lock);
 663        if (!link->irq.initialized) {
 664                mutex_unlock(&acpi_link_lock);
 665                printk(KERN_ERR PREFIX "Link isn't initialized\n");
 666                return -1;
 667        }
 668#ifdef  FUTURE_USE
 669        /*
 670         * The Link reference count allows us to _DISable an unused link
 671         * and suspend time, and set it again  on resume.
 672         * However, 2.6.12 still has irq_router.resume
 673         * which blindly restores the link state.
 674         * So we disable the reference count method
 675         * to prevent duplicate acpi_pci_link_set()
 676         * which would harm some systems
 677         */
 678        link->refcnt--;
 679#endif
 680        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 681                          "Link %s is dereferenced\n",
 682                          acpi_device_bid(link->device)));
 683
 684        if (link->refcnt == 0)
 685                acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 686
 687        mutex_unlock(&acpi_link_lock);
 688        return (link->irq.active);
 689}
 690
 691/* --------------------------------------------------------------------------
 692                                 Driver Interface
 693   -------------------------------------------------------------------------- */
 694
 695static int acpi_pci_link_add(struct acpi_device *device)
 696{
 697        int result;
 698        struct acpi_pci_link *link;
 699        int i;
 700        int found = 0;
 701
 702        link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 703        if (!link)
 704                return -ENOMEM;
 705
 706        link->device = device;
 707        strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 708        strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 709        device->driver_data = link;
 710
 711        mutex_lock(&acpi_link_lock);
 712        result = acpi_pci_link_get_possible(link);
 713        if (result)
 714                goto end;
 715
 716        /* query and set link->irq.active */
 717        acpi_pci_link_get_current(link);
 718
 719        printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 720               acpi_device_bid(device));
 721        for (i = 0; i < link->irq.possible_count; i++) {
 722                if (link->irq.active == link->irq.possible[i]) {
 723                        printk(KERN_CONT " *%d", link->irq.possible[i]);
 724                        found = 1;
 725                } else
 726                        printk(KERN_CONT " %d", link->irq.possible[i]);
 727        }
 728
 729        printk(KERN_CONT ")");
 730
 731        if (!found)
 732                printk(KERN_CONT " *%d", link->irq.active);
 733
 734        if (!link->device->status.enabled)
 735                printk(KERN_CONT ", disabled.");
 736
 737        printk(KERN_CONT "\n");
 738
 739        list_add_tail(&link->list, &acpi_link_list);
 740
 741      end:
 742        /* disable all links -- to be activated on use */
 743        acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 744        mutex_unlock(&acpi_link_lock);
 745
 746        if (result)
 747                kfree(link);
 748
 749        return result;
 750}
 751
 752static int acpi_pci_link_resume(struct acpi_pci_link *link)
 753{
 754        if (link->refcnt && link->irq.active && link->irq.initialized)
 755                return (acpi_pci_link_set(link, link->irq.active));
 756
 757        return 0;
 758}
 759
 760static void irqrouter_resume(void)
 761{
 762        struct acpi_pci_link *link;
 763
 764        list_for_each_entry(link, &acpi_link_list, list) {
 765                acpi_pci_link_resume(link);
 766        }
 767}
 768
 769static int acpi_pci_link_remove(struct acpi_device *device, int type)
 770{
 771        struct acpi_pci_link *link;
 772
 773        link = acpi_driver_data(device);
 774
 775        mutex_lock(&acpi_link_lock);
 776        list_del(&link->list);
 777        mutex_unlock(&acpi_link_lock);
 778
 779        kfree(link);
 780        return 0;
 781}
 782
 783/*
 784 * modify acpi_irq_penalty[] from cmdline
 785 */
 786static int __init acpi_irq_penalty_update(char *str, int used)
 787{
 788        int i;
 789
 790        for (i = 0; i < 16; i++) {
 791                int retval;
 792                int irq;
 793
 794                retval = get_option(&str, &irq);
 795
 796                if (!retval)
 797                        break;  /* no number found */
 798
 799                if (irq < 0)
 800                        continue;
 801
 802                if (irq >= ARRAY_SIZE(acpi_irq_penalty))
 803                        continue;
 804
 805                if (used)
 806                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 807                else
 808                        acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 809
 810                if (retval != 2)        /* no next number */
 811                        break;
 812        }
 813        return 1;
 814}
 815
 816/*
 817 * We'd like PNP to call this routine for the
 818 * single ISA_USED value for each legacy device.
 819 * But instead it calls us with each POSSIBLE setting.
 820 * There is no ISA_POSSIBLE weight, so we simply use
 821 * the (small) PCI_USING penalty.
 822 */
 823void acpi_penalize_isa_irq(int irq, int active)
 824{
 825        if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 826                if (active)
 827                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 828                else
 829                        acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 830        }
 831}
 832
 833/*
 834 * Over-ride default table to reserve additional IRQs for use by ISA
 835 * e.g. acpi_irq_isa=5
 836 * Useful for telling ACPI how not to interfere with your ISA sound card.
 837 */
 838static int __init acpi_irq_isa(char *str)
 839{
 840        return acpi_irq_penalty_update(str, 1);
 841}
 842
 843__setup("acpi_irq_isa=", acpi_irq_isa);
 844
 845/*
 846 * Over-ride default table to free additional IRQs for use by PCI
 847 * e.g. acpi_irq_pci=7,15
 848 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 849 */
 850static int __init acpi_irq_pci(char *str)
 851{
 852        return acpi_irq_penalty_update(str, 0);
 853}
 854
 855__setup("acpi_irq_pci=", acpi_irq_pci);
 856
 857static int __init acpi_irq_nobalance_set(char *str)
 858{
 859        acpi_irq_balance = 0;
 860        return 1;
 861}
 862
 863__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 864
 865static int __init acpi_irq_balance_set(char *str)
 866{
 867        acpi_irq_balance = 1;
 868        return 1;
 869}
 870
 871__setup("acpi_irq_balance", acpi_irq_balance_set);
 872
 873static struct syscore_ops irqrouter_syscore_ops = {
 874        .resume = irqrouter_resume,
 875};
 876
 877static int __init irqrouter_init_ops(void)
 878{
 879        if (!acpi_disabled && !acpi_noirq)
 880                register_syscore_ops(&irqrouter_syscore_ops);
 881
 882        return 0;
 883}
 884
 885device_initcall(irqrouter_init_ops);
 886
 887static int __init acpi_pci_link_init(void)
 888{
 889        if (acpi_noirq)
 890                return 0;
 891
 892        if (acpi_irq_balance == -1) {
 893                /* no command line switch: enable balancing in IOAPIC mode */
 894                if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 895                        acpi_irq_balance = 1;
 896                else
 897                        acpi_irq_balance = 0;
 898        }
 899
 900        if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 901                return -ENODEV;
 902
 903        return 0;
 904}
 905
 906subsys_initcall(acpi_pci_link_init);
 907
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