LXR linux/drivers/acpi/pci

   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/sysdev.h>
  33#include <linux/kernel.h>
  34#include <linux/module.h>
  35#include <linux/init.h>
  36#include <linux/types.h>
  37#include <linux/proc_fs.h>
  38#include <linux/spinlock.h>
  39#include <linux/pm.h>
  40#include <linux/pci.h>
  41#include <linux/mutex.h>
  42
  43#include <acpi/acpi_bus.h>
  44#include <acpi/acpi_drivers.h>
  45
  46#define _COMPONENT                      ACPI_PCI_COMPONENT
  47ACPI_MODULE_NAME("pci_link");
  48#define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  49#define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  50#define ACPI_PCI_LINK_FILE_INFO         "info"
  51#define ACPI_PCI_LINK_FILE_STATUS       "state"
  52#define ACPI_PCI_LINK_MAX_POSSIBLE      16
  53
  54static int acpi_pci_link_add(struct acpi_device *device);
  55static int acpi_pci_link_remove(struct acpi_device *device, int type);
  56
  57static struct acpi_device_id link_device_ids[] = {
  58        {"PNP0C0F", 0},
  59        {"", 0},
  60};
  61MODULE_DEVICE_TABLE(acpi, link_device_ids);
  62
  63static struct acpi_driver acpi_pci_link_driver = {
  64        .name = "pci_link",
  65        .class = ACPI_PCI_LINK_CLASS,
  66        .ids = link_device_ids,
  67        .ops = {
  68                .add = acpi_pci_link_add,
  69                .remove = acpi_pci_link_remove,
  70        },
  71};
  72
  73/*
  74 * If a link is initialized, we never change its active and initialized
  75 * later even the link is disable. Instead, we just repick the active irq
  76 */
  77struct acpi_pci_link_irq {
  78        u8 active;              /* Current IRQ */
  79        u8 triggering;          /* All IRQs */
  80        u8 polarity;            /* All IRQs */
  81        u8 resource_type;
  82        u8 possible_count;
  83        u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  84        u8 initialized:1;
  85        u8 reserved:7;
  86};
  87
  88struct acpi_pci_link {
  89        struct list_head                list;
  90        struct acpi_device              *device;
  91        struct acpi_pci_link_irq        irq;
  92        int                             refcnt;
  93};
  94
  95static LIST_HEAD(acpi_link_list);
  96static DEFINE_MUTEX(acpi_link_lock);
  97
  98/* --------------------------------------------------------------------------
  99                            PCI Link Device Management
 100   -------------------------------------------------------------------------- */
 101
 102/*
 103 * set context (link) possible list from resource list
 104 */
 105static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
 106                                                void *context)
 107{
 108        struct acpi_pci_link *link = context;
 109        u32 i;
 110
 111        switch (resource->type) {
 112        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 113        case ACPI_RESOURCE_TYPE_END_TAG:
 114                return AE_OK;
 115        case ACPI_RESOURCE_TYPE_IRQ:
 116                {
 117                        struct acpi_resource_irq *p = &resource->data.irq;
 118                        if (!p || !p->interrupt_count) {
 119                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 120                                                  "Blank _PRS IRQ resource\n"));
 121                                return AE_OK;
 122                        }
 123                        for (i = 0;
 124                             (i < p->interrupt_count
 125                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 126                                if (!p->interrupts[i]) {
 127                                        printk(KERN_WARNING PREFIX
 128                                               "Invalid _PRS IRQ %d\n",
 129                                               p->interrupts[i]);
 130                                        continue;
 131                                }
 132                                link->irq.possible[i] = p->interrupts[i];
 133                                link->irq.possible_count++;
 134                        }
 135                        link->irq.triggering = p->triggering;
 136                        link->irq.polarity = p->polarity;
 137                        link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 138                        break;
 139                }
 140        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 141                {
 142                        struct acpi_resource_extended_irq *p =
 143                            &resource->data.extended_irq;
 144                        if (!p || !p->interrupt_count) {
 145                                printk(KERN_WARNING PREFIX
 146                                              "Blank _PRS EXT IRQ resource\n");
 147                                return AE_OK;
 148                        }
 149                        for (i = 0;
 150                             (i < p->interrupt_count
 151                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 152                                if (!p->interrupts[i]) {
 153                                        printk(KERN_WARNING PREFIX
 154                                               "Invalid _PRS IRQ %d\n",
 155                                               p->interrupts[i]);
 156                                        continue;
 157                                }
 158                                link->irq.possible[i] = p->interrupts[i];
 159                                link->irq.possible_count++;
 160                        }
 161                        link->irq.triggering = p->triggering;
 162                        link->irq.polarity = p->polarity;
 163                        link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 164                        break;
 165                }
 166        default:
 167                printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 168                       resource->type);
 169                return AE_OK;
 170        }
 171
 172        return AE_CTRL_TERMINATE;
 173}
 174
 175static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 176{
 177        acpi_status status;
 178
 179        status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 180                                     acpi_pci_link_check_possible, link);
 181        if (ACPI_FAILURE(status)) {
 182                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 183                return -ENODEV;
 184        }
 185
 186        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 187                          "Found %d possible IRQs\n",
 188                          link->irq.possible_count));
 189
 190        return 0;
 191}
 192
 193static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 194                                               void *context)
 195{
 196        int *irq = context;
 197
 198        switch (resource->type) {
 199        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 200        case ACPI_RESOURCE_TYPE_END_TAG:
 201                return AE_OK;
 202        case ACPI_RESOURCE_TYPE_IRQ:
 203                {
 204                        struct acpi_resource_irq *p = &resource->data.irq;
 205                        if (!p || !p->interrupt_count) {
 206                                /*
 207                                 * IRQ descriptors may have no IRQ# bits set,
 208                                 * particularly those those w/ _STA disabled
 209                                 */
 210                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 211                                                  "Blank _CRS IRQ resource\n"));
 212                                return AE_OK;
 213                        }
 214                        *irq = p->interrupts[0];
 215                        break;
 216                }
 217        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 218                {
 219                        struct acpi_resource_extended_irq *p =
 220                            &resource->data.extended_irq;
 221                        if (!p || !p->interrupt_count) {
 222                                /*
 223                                 * extended IRQ descriptors must
 224                                 * return at least 1 IRQ
 225                                 */
 226                                printk(KERN_WARNING PREFIX
 227                                              "Blank _CRS EXT IRQ resource\n");
 228                                return AE_OK;
 229                        }
 230                        *irq = p->interrupts[0];
 231                        break;
 232                }
 233                break;
 234        default:
 235                printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 236                       resource->type);
 237                return AE_OK;
 238        }
 239
 240        return AE_CTRL_TERMINATE;
 241}
 242
 243/*
 244 * Run _CRS and set link->irq.active
 245 *
 246 * return value:
 247 * 0 - success
 248 * !0 - failure
 249 */
 250static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 251{
 252        int result = 0;
 253        acpi_status status;
 254        int irq = 0;
 255
 256        link->irq.active = 0;
 257
 258        /* in practice, status disabled is meaningless, ignore it */
 259        if (acpi_strict) {
 260                /* Query _STA, set link->device->status */
 261                result = acpi_bus_get_status(link->device);
 262                if (result) {
 263                        printk(KERN_ERR PREFIX "Unable to read status\n");
 264                        goto end;
 265                }
 266
 267                if (!link->device->status.enabled) {
 268                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 269                        return 0;
 270                }
 271        }
 272
 273        /* 
 274         * Query and parse _CRS to get the current IRQ assignment. 
 275         */
 276
 277        status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 278                                     acpi_pci_link_check_current, &irq);
 279        if (ACPI_FAILURE(status)) {
 280                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 281                result = -ENODEV;
 282                goto end;
 283        }
 284
 285        if (acpi_strict && !irq) {
 286                printk(KERN_ERR PREFIX "_CRS returned 0\n");
 287                result = -ENODEV;
 288        }
 289
 290        link->irq.active = irq;
 291
 292        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 293
 294      end:
 295        return result;
 296}
 297
 298static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 299{
 300        int result;
 301        acpi_status status;
 302        struct {
 303                struct acpi_resource res;
 304                struct acpi_resource end;
 305        } *resource;
 306        struct acpi_buffer buffer = { 0, NULL };
 307
 308        if (!irq)
 309                return -EINVAL;
 310
 311        resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 312        if (!resource)
 313                return -ENOMEM;
 314
 315        buffer.length = sizeof(*resource) + 1;
 316        buffer.pointer = resource;
 317
 318        switch (link->irq.resource_type) {
 319        case ACPI_RESOURCE_TYPE_IRQ:
 320                resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 321                resource->res.length = sizeof(struct acpi_resource);
 322                resource->res.data.irq.triggering = link->irq.triggering;
 323                resource->res.data.irq.polarity =
 324                    link->irq.polarity;
 325                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 326                        resource->res.data.irq.sharable =
 327                            ACPI_EXCLUSIVE;
 328                else
 329                        resource->res.data.irq.sharable = ACPI_SHARED;
 330                resource->res.data.irq.interrupt_count = 1;
 331                resource->res.data.irq.interrupts[0] = irq;
 332                break;
 333
 334        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 335                resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 336                resource->res.length = sizeof(struct acpi_resource);
 337                resource->res.data.extended_irq.producer_consumer =
 338                    ACPI_CONSUMER;
 339                resource->res.data.extended_irq.triggering =
 340                    link->irq.triggering;
 341                resource->res.data.extended_irq.polarity =
 342                    link->irq.polarity;
 343                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 344                        resource->res.data.irq.sharable =
 345                            ACPI_EXCLUSIVE;
 346                else
 347                        resource->res.data.irq.sharable = ACPI_SHARED;
 348                resource->res.data.extended_irq.interrupt_count = 1;
 349                resource->res.data.extended_irq.interrupts[0] = irq;
 350                /* ignore resource_source, it's optional */
 351                break;
 352        default:
 353                printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 354                result = -EINVAL;
 355                goto end;
 356
 357        }
 358        resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 359
 360        /* Attempt to set the resource */
 361        status = acpi_set_current_resources(link->device->handle, &buffer);
 362
 363        /* check for total failure */
 364        if (ACPI_FAILURE(status)) {
 365                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 366                result = -ENODEV;
 367                goto end;
 368        }
 369
 370        /* Query _STA, set device->status */
 371        result = acpi_bus_get_status(link->device);
 372        if (result) {
 373                printk(KERN_ERR PREFIX "Unable to read status\n");
 374                goto end;
 375        }
 376        if (!link->device->status.enabled) {
 377                printk(KERN_WARNING PREFIX
 378                              "%s [%s] disabled and referenced, BIOS bug\n",
 379                              acpi_device_name(link->device),
 380                              acpi_device_bid(link->device));
 381        }
 382
 383        /* Query _CRS, set link->irq.active */
 384        result = acpi_pci_link_get_current(link);
 385        if (result) {
 386                goto end;
 387        }
 388
 389        /*
 390         * Is current setting not what we set?
 391         * set link->irq.active
 392         */
 393        if (link->irq.active != irq) {
 394                /*
 395                 * policy: when _CRS doesn't return what we just _SRS
 396                 * assume _SRS worked and override _CRS value.
 397                 */
 398                printk(KERN_WARNING PREFIX
 399                              "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 400                              acpi_device_name(link->device),
 401                              acpi_device_bid(link->device), link->irq.active, irq);
 402                link->irq.active = irq;
 403        }
 404
 405        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 406
 407      end:
 408        kfree(resource);
 409        return result;
 410}
 411
 412/* --------------------------------------------------------------------------
 413                            PCI Link IRQ Management
 414   -------------------------------------------------------------------------- */
 415
 416/*
 417 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 418 * Link Devices to move the PIRQs around to minimize sharing.
 419 * 
 420 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 421 * that the BIOS has already set to active.  This is necessary because
 422 * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 423 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 424 * even if acpi_irq_nobalance is set.
 425 *
 426 * A tables of penalties avoids directing PCI interrupts to well known
 427 * ISA IRQs. Boot params are available to over-ride the default table:
 428 *
 429 * List interrupts that are free for PCI use.
 430 * acpi_irq_pci=n[,m]
 431 *
 432 * List interrupts that should not be used for PCI:
 433 * acpi_irq_isa=n[,m]
 434 *
 435 * Note that PCI IRQ routers have a list of possible IRQs,
 436 * which may not include the IRQs this table says are available.
 437 * 
 438 * Since this heuristic can't tell the difference between a link
 439 * that no device will attach to, vs. a link which may be shared
 440 * by multiple active devices -- it is not optimal.
 441 *
 442 * If interrupt performance is that important, get an IO-APIC system
 443 * with a pin dedicated to each device.  Or for that matter, an MSI
 444 * enabled system.
 445 */
 446
 447#define ACPI_MAX_IRQS           256
 448#define ACPI_MAX_ISA_IRQ        16
 449
 450#define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 451#define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 452#define PIRQ_PENALTY_PCI_USING          (16*16*16)
 453#define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 454#define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 455#define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 456
 457static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 458        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 459        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 460        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 461        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 462        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 463        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 464        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 465        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 466        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 467        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 468        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 469        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 470        PIRQ_PENALTY_ISA_USED,          /* IRQ12 mouse */
 471        PIRQ_PENALTY_ISA_USED,          /* IRQ13 fpe, sometimes */
 472        PIRQ_PENALTY_ISA_USED,          /* IRQ14 ide0 */
 473        PIRQ_PENALTY_ISA_USED,          /* IRQ15 ide1 */
 474        /* >IRQ15 */
 475};
 476
 477int __init acpi_irq_penalty_init(void)
 478{
 479        struct acpi_pci_link *link;
 480        int i;
 481
 482        /*
 483         * Update penalties to facilitate IRQ balancing.
 484         */
 485        list_for_each_entry(link, &acpi_link_list, list) {
 486
 487                /*
 488                 * reflect the possible and active irqs in the penalty table --
 489                 * useful for breaking ties.
 490                 */
 491                if (link->irq.possible_count) {
 492                        int penalty =
 493                            PIRQ_PENALTY_PCI_POSSIBLE /
 494                            link->irq.possible_count;
 495
 496                        for (i = 0; i < link->irq.possible_count; i++) {
 497                                if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 498                                        acpi_irq_penalty[link->irq.
 499                                                         possible[i]] +=
 500                                            penalty;
 501                        }
 502
 503                } else if (link->irq.active) {
 504                        acpi_irq_penalty[link->irq.active] +=
 505                            PIRQ_PENALTY_PCI_POSSIBLE;
 506                }
 507        }
 508        /* Add a penalty for the SCI */
 509        acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
 510        return 0;
 511}
 512
 513static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 514
 515static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 516{
 517        int irq;
 518        int i;
 519
 520        if (link->irq.initialized) {
 521                if (link->refcnt == 0)
 522                        /* This means the link is disabled but initialized */
 523                        acpi_pci_link_set(link, link->irq.active);
 524                return 0;
 525        }
 526
 527        /*
 528         * search for active IRQ in list of possible IRQs.
 529         */
 530        for (i = 0; i < link->irq.possible_count; ++i) {
 531                if (link->irq.active == link->irq.possible[i])
 532                        break;
 533        }
 534        /*
 535         * forget active IRQ that is not in possible list
 536         */
 537        if (i == link->irq.possible_count) {
 538                if (acpi_strict)
 539                        printk(KERN_WARNING PREFIX "_CRS %d not found"
 540                                      " in _PRS\n", link->irq.active);
 541                link->irq.active = 0;
 542        }
 543
 544        /*
 545         * if active found, use it; else pick entry from end of possible list.
 546         */
 547        if (link->irq.active)
 548                irq = link->irq.active;
 549        else
 550                irq = link->irq.possible[link->irq.possible_count - 1];
 551
 552        if (acpi_irq_balance || !link->irq.active) {
 553                /*
 554                 * Select the best IRQ.  This is done in reverse to promote
 555                 * the use of IRQs 9, 10, 11, and >15.
 556                 */
 557                for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 558                        if (acpi_irq_penalty[irq] >
 559                            acpi_irq_penalty[link->irq.possible[i]])
 560                                irq = link->irq.possible[i];
 561                }
 562        }
 563
 564        /* Attempt to enable the link device at this IRQ. */
 565        if (acpi_pci_link_set(link, irq)) {
 566                printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 567                            "Try pci=noacpi or acpi=off\n",
 568                            acpi_device_name(link->device),
 569                            acpi_device_bid(link->device));
 570                return -ENODEV;
 571        } else {
 572                acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 573                printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
 574                       acpi_device_name(link->device),
 575                       acpi_device_bid(link->device), link->irq.active);
 576        }
 577
 578        link->irq.initialized = 1;
 579        return 0;
 580}
 581
 582/*
 583 * acpi_pci_link_allocate_irq
 584 * success: return IRQ >= 0
 585 * failure: return -1
 586 */
 587int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 588                               int *polarity, char **name)
 589{
 590        int result;
 591        struct acpi_device *device;
 592        struct acpi_pci_link *link;
 593
 594        result = acpi_bus_get_device(handle, &device);
 595        if (result) {
 596                printk(KERN_ERR PREFIX "Invalid link device\n");
 597                return -1;
 598        }
 599
 600        link = acpi_driver_data(device);
 601        if (!link) {
 602                printk(KERN_ERR PREFIX "Invalid link context\n");
 603                return -1;
 604        }
 605
 606        /* TBD: Support multiple index (IRQ) entries per Link Device */
 607        if (index) {
 608                printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 609                return -1;
 610        }
 611
 612        mutex_lock(&acpi_link_lock);
 613        if (acpi_pci_link_allocate(link)) {
 614                mutex_unlock(&acpi_link_lock);
 615                return -1;
 616        }
 617
 618        if (!link->irq.active) {
 619                mutex_unlock(&acpi_link_lock);
 620                printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 621                return -1;
 622        }
 623        link->refcnt++;
 624        mutex_unlock(&acpi_link_lock);
 625
 626        if (triggering)
 627                *triggering = link->irq.triggering;
 628        if (polarity)
 629                *polarity = link->irq.polarity;
 630        if (name)
 631                *name = acpi_device_bid(link->device);
 632        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 633                          "Link %s is referenced\n",
 634                          acpi_device_bid(link->device)));
 635        return (link->irq.active);
 636}
 637
 638/*
 639 * We don't change link's irq information here.  After it is reenabled, we
 640 * continue use the info
 641 */
 642int acpi_pci_link_free_irq(acpi_handle handle)
 643{
 644        struct acpi_device *device;
 645        struct acpi_pci_link *link;
 646        acpi_status result;
 647
 648        result = acpi_bus_get_device(handle, &device);
 649        if (result) {
 650                printk(KERN_ERR PREFIX "Invalid link device\n");
 651                return -1;
 652        }
 653
 654        link = acpi_driver_data(device);
 655        if (!link) {
 656                printk(KERN_ERR PREFIX "Invalid link context\n");
 657                return -1;
 658        }
 659
 660        mutex_lock(&acpi_link_lock);
 661        if (!link->irq.initialized) {
 662                mutex_unlock(&acpi_link_lock);
 663                printk(KERN_ERR PREFIX "Link isn't initialized\n");
 664                return -1;
 665        }
 666#ifdef  FUTURE_USE
 667        /*
 668         * The Link reference count allows us to _DISable an unused link
 669         * and suspend time, and set it again  on resume.
 670         * However, 2.6.12 still has irq_router.resume
 671         * which blindly restores the link state.
 672         * So we disable the reference count method
 673         * to prevent duplicate acpi_pci_link_set()
 674         * which would harm some systems
 675         */
 676        link->refcnt--;
 677#endif
 678        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 679                          "Link %s is dereferenced\n",
 680                          acpi_device_bid(link->device)));
 681
 682        if (link->refcnt == 0)
 683                acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 684
 685        mutex_unlock(&acpi_link_lock);
 686        return (link->irq.active);
 687}
 688
 689/* --------------------------------------------------------------------------
 690                                 Driver Interface
 691   -------------------------------------------------------------------------- */
 692
 693static int acpi_pci_link_add(struct acpi_device *device)
 694{
 695        int result;
 696        struct acpi_pci_link *link;
 697        int i;
 698        int found = 0;
 699
 700        link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 701        if (!link)
 702                return -ENOMEM;
 703
 704        link->device = device;
 705        strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 706        strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 707        device->driver_data = link;
 708
 709        mutex_lock(&acpi_link_lock);
 710        result = acpi_pci_link_get_possible(link);
 711        if (result)
 712                goto end;
 713
 714        /* query and set link->irq.active */
 715        acpi_pci_link_get_current(link);
 716
 717        printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 718               acpi_device_bid(device));
 719        for (i = 0; i < link->irq.possible_count; i++) {
 720                if (link->irq.active == link->irq.possible[i]) {
 721                        printk(" *%d", link->irq.possible[i]);
 722                        found = 1;
 723                } else
 724                        printk(" %d", link->irq.possible[i]);
 725        }
 726
 727        printk(")");
 728
 729        if (!found)
 730                printk(" *%d", link->irq.active);
 731
 732        if (!link->device->status.enabled)
 733                printk(", disabled.");
 734
 735        printk("\n");
 736
 737        list_add_tail(&link->list, &acpi_link_list);
 738
 739      end:
 740        /* disable all links -- to be activated on use */
 741        acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 742        mutex_unlock(&acpi_link_lock);
 743
 744        if (result)
 745                kfree(link);
 746
 747        return result;
 748}
 749
 750static int acpi_pci_link_resume(struct acpi_pci_link *link)
 751{
 752        if (link->refcnt && link->irq.active && link->irq.initialized)
 753                return (acpi_pci_link_set(link, link->irq.active));
 754
 755        return 0;
 756}
 757
 758static int irqrouter_resume(struct sys_device *dev)
 759{
 760        struct acpi_pci_link *link;
 761
 762        list_for_each_entry(link, &acpi_link_list, list) {
 763                acpi_pci_link_resume(link);
 764        }
 765        return 0;
 766}
 767
 768static int acpi_pci_link_remove(struct acpi_device *device, int type)
 769{
 770        struct acpi_pci_link *link;
 771
 772        link = acpi_driver_data(device);
 773
 774        mutex_lock(&acpi_link_lock);
 775        list_del(&link->list);
 776        mutex_unlock(&acpi_link_lock);
 777
 778        kfree(link);
 779        return 0;
 780}
 781
 782/*
 783 * modify acpi_irq_penalty[] from cmdline
 784 */
 785static int __init acpi_irq_penalty_update(char *str, int used)
 786{
 787        int i;
 788
 789        for (i = 0; i < 16; i++) {
 790                int retval;
 791                int irq;
 792
 793                retval = get_option(&str, &irq);
 794
 795                if (!retval)
 796                        break;  /* no number found */
 797
 798                if (irq < 0)
 799                        continue;
 800
 801                if (irq >= ARRAY_SIZE(acpi_irq_penalty))
 802                        continue;
 803
 804                if (used)
 805                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 806                else
 807                        acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 808
 809                if (retval != 2)        /* no next number */
 810                        break;
 811        }
 812        return 1;
 813}
 814
 815/*
 816 * We'd like PNP to call this routine for the
 817 * single ISA_USED value for each legacy device.
 818 * But instead it calls us with each POSSIBLE setting.
 819 * There is no ISA_POSSIBLE weight, so we simply use
 820 * the (small) PCI_USING penalty.
 821 */
 822void acpi_penalize_isa_irq(int irq, int active)
 823{
 824        if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 825                if (active)
 826                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 827                else
 828                        acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 829        }
 830}
 831
 832/*
 833 * Over-ride default table to reserve additional IRQs for use by ISA
 834 * e.g. acpi_irq_isa=5
 835 * Useful for telling ACPI how not to interfere with your ISA sound card.
 836 */
 837static int __init acpi_irq_isa(char *str)
 838{
 839        return acpi_irq_penalty_update(str, 1);
 840}
 841
 842__setup("acpi_irq_isa=", acpi_irq_isa);
 843
 844/*
 845 * Over-ride default table to free additional IRQs for use by PCI
 846 * e.g. acpi_irq_pci=7,15
 847 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 848 */
 849static int __init acpi_irq_pci(char *str)
 850{
 851        return acpi_irq_penalty_update(str, 0);
 852}
 853
 854__setup("acpi_irq_pci=", acpi_irq_pci);
 855
 856static int __init acpi_irq_nobalance_set(char *str)
 857{
 858        acpi_irq_balance = 0;
 859        return 1;
 860}
 861
 862__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 863
 864static int __init acpi_irq_balance_set(char *str)
 865{
 866        acpi_irq_balance = 1;
 867        return 1;
 868}
 869
 870__setup("acpi_irq_balance", acpi_irq_balance_set);
 871
 872/* FIXME: we will remove this interface after all drivers call pci_disable_device */
 873static struct sysdev_class irqrouter_sysdev_class = {
 874        .name = "irqrouter",
 875        .resume = irqrouter_resume,
 876};
 877
 878static struct sys_device device_irqrouter = {
 879        .id = 0,
 880        .cls = &irqrouter_sysdev_class,
 881};
 882
 883static int __init irqrouter_init_sysfs(void)
 884{
 885        int error;
 886
 887        if (acpi_disabled || acpi_noirq)
 888                return 0;
 889
 890        error = sysdev_class_register(&irqrouter_sysdev_class);
 891        if (!error)
 892                error = sysdev_register(&device_irqrouter);
 893
 894        return error;
 895}
 896
 897device_initcall(irqrouter_init_sysfs);
 898
 899static int __init acpi_pci_link_init(void)
 900{
 901        if (acpi_noirq)
 902                return 0;
 903
 904        if (acpi_irq_balance == -1) {
 905                /* no command line switch: enable balancing in IOAPIC mode */
 906                if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 907                        acpi_irq_balance = 1;
 908                else
 909                        acpi_irq_balance = 0;
 910        }
 911
 912        if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 913                return -ENODEV;
 914
 915        return 0;
 916}
 917
 918subsys_initcall(acpi_pci_link_init);
 919