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 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  21 *
  22 * TBD: 
  23 *      1. Support more than one IRQ resource entry per link device (index).
  24 *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  25 *         for IRQ management (e.g. start()->_SRS).
  26 */
  27
  28#include <linux/syscore_ops.h>
  29#include <linux/kernel.h>
  30#include <linux/module.h>
  31#include <linux/init.h>
  32#include <linux/types.h>
  33#include <linux/spinlock.h>
  34#include <linux/pm.h>
  35#include <linux/pci.h>
  36#include <linux/mutex.h>
  37#include <linux/slab.h>
  38#include <linux/acpi.h>
  39
  40#include "internal.h"
  41
  42#define _COMPONENT                      ACPI_PCI_COMPONENT
  43ACPI_MODULE_NAME("pci_link");
  44#define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  45#define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  46#define ACPI_PCI_LINK_FILE_INFO         "info"
  47#define ACPI_PCI_LINK_FILE_STATUS       "state"
  48#define ACPI_PCI_LINK_MAX_POSSIBLE      16
  49
  50static int acpi_pci_link_add(struct acpi_device *device,
  51                             const struct acpi_device_id *not_used);
  52static void acpi_pci_link_remove(struct acpi_device *device);
  53
  54static const struct acpi_device_id link_device_ids[] = {
  55        {"PNP0C0F", 0},
  56        {"", 0},
  57};
  58
  59static struct acpi_scan_handler pci_link_handler = {
  60        .ids = link_device_ids,
  61        .attach = acpi_pci_link_add,
  62        .detach = acpi_pci_link_remove,
  63};
  64
  65/*
  66 * If a link is initialized, we never change its active and initialized
  67 * later even the link is disable. Instead, we just repick the active irq
  68 */
  69struct acpi_pci_link_irq {
  70        u32 active;             /* Current IRQ */
  71        u8 triggering;          /* All IRQs */
  72        u8 polarity;            /* All IRQs */
  73        u8 resource_type;
  74        u8 possible_count;
  75        u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  76        u8 initialized:1;
  77        u8 reserved:7;
  78};
  79
  80struct acpi_pci_link {
  81        struct list_head                list;
  82        struct acpi_device              *device;
  83        struct acpi_pci_link_irq        irq;
  84        int                             refcnt;
  85};
  86
  87static LIST_HEAD(acpi_link_list);
  88static DEFINE_MUTEX(acpi_link_lock);
  89
  90/* --------------------------------------------------------------------------
  91                            PCI Link Device Management
  92   -------------------------------------------------------------------------- */
  93
  94/*
  95 * set context (link) possible list from resource list
  96 */
  97static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
  98                                                void *context)
  99{
 100        struct acpi_pci_link *link = context;
 101        u32 i;
 102
 103        switch (resource->type) {
 104        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 105        case ACPI_RESOURCE_TYPE_END_TAG:
 106                return AE_OK;
 107        case ACPI_RESOURCE_TYPE_IRQ:
 108                {
 109                        struct acpi_resource_irq *p = &resource->data.irq;
 110                        if (!p || !p->interrupt_count) {
 111                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 112                                                  "Blank _PRS IRQ resource\n"));
 113                                return AE_OK;
 114                        }
 115                        for (i = 0;
 116                             (i < p->interrupt_count
 117                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 118                                if (!p->interrupts[i]) {
 119                                        printk(KERN_WARNING PREFIX
 120                                               "Invalid _PRS IRQ %d\n",
 121                                               p->interrupts[i]);
 122                                        continue;
 123                                }
 124                                link->irq.possible[i] = p->interrupts[i];
 125                                link->irq.possible_count++;
 126                        }
 127                        link->irq.triggering = p->triggering;
 128                        link->irq.polarity = p->polarity;
 129                        link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 130                        break;
 131                }
 132        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 133                {
 134                        struct acpi_resource_extended_irq *p =
 135                            &resource->data.extended_irq;
 136                        if (!p || !p->interrupt_count) {
 137                                printk(KERN_WARNING PREFIX
 138                                              "Blank _PRS EXT IRQ resource\n");
 139                                return AE_OK;
 140                        }
 141                        for (i = 0;
 142                             (i < p->interrupt_count
 143                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 144                                if (!p->interrupts[i]) {
 145                                        printk(KERN_WARNING PREFIX
 146                                               "Invalid _PRS IRQ %d\n",
 147                                               p->interrupts[i]);
 148                                        continue;
 149                                }
 150                                link->irq.possible[i] = p->interrupts[i];
 151                                link->irq.possible_count++;
 152                        }
 153                        link->irq.triggering = p->triggering;
 154                        link->irq.polarity = p->polarity;
 155                        link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 156                        break;
 157                }
 158        default:
 159                printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 160                       resource->type);
 161                return AE_OK;
 162        }
 163
 164        return AE_CTRL_TERMINATE;
 165}
 166
 167static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 168{
 169        acpi_status status;
 170
 171        status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 172                                     acpi_pci_link_check_possible, link);
 173        if (ACPI_FAILURE(status)) {
 174                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 175                return -ENODEV;
 176        }
 177
 178        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 179                          "Found %d possible IRQs\n",
 180                          link->irq.possible_count));
 181
 182        return 0;
 183}
 184
 185static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 186                                               void *context)
 187{
 188        int *irq = context;
 189
 190        switch (resource->type) {
 191        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 192        case ACPI_RESOURCE_TYPE_END_TAG:
 193                return AE_OK;
 194        case ACPI_RESOURCE_TYPE_IRQ:
 195                {
 196                        struct acpi_resource_irq *p = &resource->data.irq;
 197                        if (!p || !p->interrupt_count) {
 198                                /*
 199                                 * IRQ descriptors may have no IRQ# bits set,
 200                                 * particularly those those w/ _STA disabled
 201                                 */
 202                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 203                                                  "Blank _CRS IRQ resource\n"));
 204                                return AE_OK;
 205                        }
 206                        *irq = p->interrupts[0];
 207                        break;
 208                }
 209        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 210                {
 211                        struct acpi_resource_extended_irq *p =
 212                            &resource->data.extended_irq;
 213                        if (!p || !p->interrupt_count) {
 214                                /*
 215                                 * extended IRQ descriptors must
 216                                 * return at least 1 IRQ
 217                                 */
 218                                printk(KERN_WARNING PREFIX
 219                                              "Blank _CRS EXT IRQ resource\n");
 220                                return AE_OK;
 221                        }
 222                        *irq = p->interrupts[0];
 223                        break;
 224                }
 225                break;
 226        default:
 227                printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 228                       resource->type);
 229                return AE_OK;
 230        }
 231
 232        return AE_CTRL_TERMINATE;
 233}
 234
 235/*
 236 * Run _CRS and set link->irq.active
 237 *
 238 * return value:
 239 * 0 - success
 240 * !0 - failure
 241 */
 242static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 243{
 244        int result = 0;
 245        acpi_status status;
 246        int irq = 0;
 247
 248        link->irq.active = 0;
 249
 250        /* in practice, status disabled is meaningless, ignore it */
 251        if (acpi_strict) {
 252                /* Query _STA, set link->device->status */
 253                result = acpi_bus_get_status(link->device);
 254                if (result) {
 255                        printk(KERN_ERR PREFIX "Unable to read status\n");
 256                        goto end;
 257                }
 258
 259                if (!link->device->status.enabled) {
 260                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 261                        return 0;
 262                }
 263        }
 264
 265        /* 
 266         * Query and parse _CRS to get the current IRQ assignment. 
 267         */
 268
 269        status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 270                                     acpi_pci_link_check_current, &irq);
 271        if (ACPI_FAILURE(status)) {
 272                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 273                result = -ENODEV;
 274                goto end;
 275        }
 276
 277        if (acpi_strict && !irq) {
 278                printk(KERN_ERR PREFIX "_CRS returned 0\n");
 279                result = -ENODEV;
 280        }
 281
 282        link->irq.active = irq;
 283
 284        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 285
 286      end:
 287        return result;
 288}
 289
 290static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 291{
 292        int result;
 293        acpi_status status;
 294        struct {
 295                struct acpi_resource res;
 296                struct acpi_resource end;
 297        } *resource;
 298        struct acpi_buffer buffer = { 0, NULL };
 299
 300        if (!irq)
 301                return -EINVAL;
 302
 303        resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 304        if (!resource)
 305                return -ENOMEM;
 306
 307        buffer.length = sizeof(*resource) + 1;
 308        buffer.pointer = resource;
 309
 310        switch (link->irq.resource_type) {
 311        case ACPI_RESOURCE_TYPE_IRQ:
 312                resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 313                resource->res.length = sizeof(struct acpi_resource);
 314                resource->res.data.irq.triggering = link->irq.triggering;
 315                resource->res.data.irq.polarity =
 316                    link->irq.polarity;
 317                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 318                        resource->res.data.irq.sharable =
 319                            ACPI_EXCLUSIVE;
 320                else
 321                        resource->res.data.irq.sharable = ACPI_SHARED;
 322                resource->res.data.irq.interrupt_count = 1;
 323                resource->res.data.irq.interrupts[0] = irq;
 324                break;
 325
 326        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 327                resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 328                resource->res.length = sizeof(struct acpi_resource);
 329                resource->res.data.extended_irq.producer_consumer =
 330                    ACPI_CONSUMER;
 331                resource->res.data.extended_irq.triggering =
 332                    link->irq.triggering;
 333                resource->res.data.extended_irq.polarity =
 334                    link->irq.polarity;
 335                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 336                        resource->res.data.irq.sharable =
 337                            ACPI_EXCLUSIVE;
 338                else
 339                        resource->res.data.irq.sharable = ACPI_SHARED;
 340                resource->res.data.extended_irq.interrupt_count = 1;
 341                resource->res.data.extended_irq.interrupts[0] = irq;
 342                /* ignore resource_source, it's optional */
 343                break;
 344        default:
 345                printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 346                result = -EINVAL;
 347                goto end;
 348
 349        }
 350        resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 351        resource->end.length = sizeof(struct acpi_resource);
 352
 353        /* Attempt to set the resource */
 354        status = acpi_set_current_resources(link->device->handle, &buffer);
 355
 356        /* check for total failure */
 357        if (ACPI_FAILURE(status)) {
 358                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 359                result = -ENODEV;
 360                goto end;
 361        }
 362
 363        /* Query _STA, set device->status */
 364        result = acpi_bus_get_status(link->device);
 365        if (result) {
 366                printk(KERN_ERR PREFIX "Unable to read status\n");
 367                goto end;
 368        }
 369        if (!link->device->status.enabled) {
 370                printk(KERN_WARNING PREFIX
 371                              "%s [%s] disabled and referenced, BIOS bug\n",
 372                              acpi_device_name(link->device),
 373                              acpi_device_bid(link->device));
 374        }
 375
 376        /* Query _CRS, set link->irq.active */
 377        result = acpi_pci_link_get_current(link);
 378        if (result) {
 379                goto end;
 380        }
 381
 382        /*
 383         * Is current setting not what we set?
 384         * set link->irq.active
 385         */
 386        if (link->irq.active != irq) {
 387                /*
 388                 * policy: when _CRS doesn't return what we just _SRS
 389                 * assume _SRS worked and override _CRS value.
 390                 */
 391                printk(KERN_WARNING PREFIX
 392                              "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 393                              acpi_device_name(link->device),
 394                              acpi_device_bid(link->device), link->irq.active, irq);
 395                link->irq.active = irq;
 396        }
 397
 398        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 399
 400      end:
 401        kfree(resource);
 402        return result;
 403}
 404
 405/* --------------------------------------------------------------------------
 406                            PCI Link IRQ Management
 407   -------------------------------------------------------------------------- */
 408
 409/*
 410 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 411 * Link Devices to move the PIRQs around to minimize sharing.
 412 * 
 413 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 414 * that the BIOS has already set to active.  This is necessary because
 415 * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 416 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 417 * even if acpi_irq_nobalance is set.
 418 *
 419 * A tables of penalties avoids directing PCI interrupts to well known
 420 * ISA IRQs. Boot params are available to over-ride the default table:
 421 *
 422 * List interrupts that are free for PCI use.
 423 * acpi_irq_pci=n[,m]
 424 *
 425 * List interrupts that should not be used for PCI:
 426 * acpi_irq_isa=n[,m]
 427 *
 428 * Note that PCI IRQ routers have a list of possible IRQs,
 429 * which may not include the IRQs this table says are available.
 430 * 
 431 * Since this heuristic can't tell the difference between a link
 432 * that no device will attach to, vs. a link which may be shared
 433 * by multiple active devices -- it is not optimal.
 434 *
 435 * If interrupt performance is that important, get an IO-APIC system
 436 * with a pin dedicated to each device.  Or for that matter, an MSI
 437 * enabled system.
 438 */
 439
 440#define ACPI_MAX_IRQS           256
 441#define ACPI_MAX_ISA_IRQ        16
 442
 443#define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 444#define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 445#define PIRQ_PENALTY_PCI_USING          (16*16*16)
 446#define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 447#define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 448#define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 449
 450static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 451        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 452        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 453        PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 454        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 455        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 456        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 457        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 458        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 459        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 460        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 461        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 462        PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 463        PIRQ_PENALTY_ISA_USED,          /* IRQ12 mouse */
 464        PIRQ_PENALTY_ISA_USED,          /* IRQ13 fpe, sometimes */
 465        PIRQ_PENALTY_ISA_USED,          /* IRQ14 ide0 */
 466        PIRQ_PENALTY_ISA_USED,          /* IRQ15 ide1 */
 467        /* >IRQ15 */
 468};
 469
 470int __init acpi_irq_penalty_init(void)
 471{
 472        struct acpi_pci_link *link;
 473        int i;
 474
 475        /*
 476         * Update penalties to facilitate IRQ balancing.
 477         */
 478        list_for_each_entry(link, &acpi_link_list, list) {
 479
 480                /*
 481                 * reflect the possible and active irqs in the penalty table --
 482                 * useful for breaking ties.
 483                 */
 484                if (link->irq.possible_count) {
 485                        int penalty =
 486                            PIRQ_PENALTY_PCI_POSSIBLE /
 487                            link->irq.possible_count;
 488
 489                        for (i = 0; i < link->irq.possible_count; i++) {
 490                                if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 491                                        acpi_irq_penalty[link->irq.
 492                                                         possible[i]] +=
 493                                            penalty;
 494                        }
 495
 496                } else if (link->irq.active) {
 497                        acpi_irq_penalty[link->irq.active] +=
 498                            PIRQ_PENALTY_PCI_POSSIBLE;
 499                }
 500        }
 501
 502        return 0;
 503}
 504
 505static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 506
 507static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 508{
 509        int irq;
 510        int i;
 511
 512        if (link->irq.initialized) {
 513                if (link->refcnt == 0)
 514                        /* This means the link is disabled but initialized */
 515                        acpi_pci_link_set(link, link->irq.active);
 516                return 0;
 517        }
 518
 519        /*
 520         * search for active IRQ in list of possible IRQs.
 521         */
 522        for (i = 0; i < link->irq.possible_count; ++i) {
 523                if (link->irq.active == link->irq.possible[i])
 524                        break;
 525        }
 526        /*
 527         * forget active IRQ that is not in possible list
 528         */
 529        if (i == link->irq.possible_count) {
 530                if (acpi_strict)
 531                        printk(KERN_WARNING PREFIX "_CRS %d not found"
 532                                      " in _PRS\n", link->irq.active);
 533                link->irq.active = 0;
 534        }
 535
 536        /*
 537         * if active found, use it; else pick entry from end of possible list.
 538         */
 539        if (link->irq.active)
 540                irq = link->irq.active;
 541        else
 542                irq = link->irq.possible[link->irq.possible_count - 1];
 543
 544        if (acpi_irq_balance || !link->irq.active) {
 545                /*
 546                 * Select the best IRQ.  This is done in reverse to promote
 547                 * the use of IRQs 9, 10, 11, and >15.
 548                 */
 549                for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 550                        if (acpi_irq_penalty[irq] >
 551                            acpi_irq_penalty[link->irq.possible[i]])
 552                                irq = link->irq.possible[i];
 553                }
 554        }
 555        if (acpi_irq_penalty[irq] >= PIRQ_PENALTY_ISA_ALWAYS) {
 556                printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
 557                            "Try pci=noacpi or acpi=off\n",
 558                            acpi_device_name(link->device),
 559                            acpi_device_bid(link->device));
 560                return -ENODEV;
 561        }
 562
 563        /* Attempt to enable the link device at this IRQ. */
 564        if (acpi_pci_link_set(link, irq)) {
 565                printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 566                            "Try pci=noacpi or acpi=off\n",
 567                            acpi_device_name(link->device),
 568                            acpi_device_bid(link->device));
 569                return -ENODEV;
 570        } else {
 571                acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 572                printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
 573                       acpi_device_name(link->device),
 574                       acpi_device_bid(link->device), link->irq.active);
 575        }
 576
 577        link->irq.initialized = 1;
 578        return 0;
 579}
 580
 581/*
 582 * acpi_pci_link_allocate_irq
 583 * success: return IRQ >= 0
 584 * failure: return -1
 585 */
 586int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 587                               int *polarity, char **name)
 588{
 589        int result;
 590        struct acpi_device *device;
 591        struct acpi_pci_link *link;
 592
 593        result = acpi_bus_get_device(handle, &device);
 594        if (result) {
 595                printk(KERN_ERR PREFIX "Invalid link device\n");
 596                return -1;
 597        }
 598
 599        link = acpi_driver_data(device);
 600        if (!link) {
 601                printk(KERN_ERR PREFIX "Invalid link context\n");
 602                return -1;
 603        }
 604
 605        /* TBD: Support multiple index (IRQ) entries per Link Device */
 606        if (index) {
 607                printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 608                return -1;
 609        }
 610
 611        mutex_lock(&acpi_link_lock);
 612        if (acpi_pci_link_allocate(link)) {
 613                mutex_unlock(&acpi_link_lock);
 614                return -1;
 615        }
 616
 617        if (!link->irq.active) {
 618                mutex_unlock(&acpi_link_lock);
 619                printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 620                return -1;
 621        }
 622        link->refcnt++;
 623        mutex_unlock(&acpi_link_lock);
 624
 625        if (triggering)
 626                *triggering = link->irq.triggering;
 627        if (polarity)
 628                *polarity = link->irq.polarity;
 629        if (name)
 630                *name = acpi_device_bid(link->device);
 631        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 632                          "Link %s is referenced\n",
 633                          acpi_device_bid(link->device)));
 634        return (link->irq.active);
 635}
 636
 637/*
 638 * We don't change link's irq information here.  After it is reenabled, we
 639 * continue use the info
 640 */
 641int acpi_pci_link_free_irq(acpi_handle handle)
 642{
 643        struct acpi_device *device;
 644        struct acpi_pci_link *link;
 645        acpi_status result;
 646
 647        result = acpi_bus_get_device(handle, &device);
 648        if (result) {
 649                printk(KERN_ERR PREFIX "Invalid link device\n");
 650                return -1;
 651        }
 652
 653        link = acpi_driver_data(device);
 654        if (!link) {
 655                printk(KERN_ERR PREFIX "Invalid link context\n");
 656                return -1;
 657        }
 658
 659        mutex_lock(&acpi_link_lock);
 660        if (!link->irq.initialized) {
 661                mutex_unlock(&acpi_link_lock);
 662                printk(KERN_ERR PREFIX "Link isn't initialized\n");
 663                return -1;
 664        }
 665#ifdef  FUTURE_USE
 666        /*
 667         * The Link reference count allows us to _DISable an unused link
 668         * and suspend time, and set it again  on resume.
 669         * However, 2.6.12 still has irq_router.resume
 670         * which blindly restores the link state.
 671         * So we disable the reference count method
 672         * to prevent duplicate acpi_pci_link_set()
 673         * which would harm some systems
 674         */
 675        link->refcnt--;
 676#endif
 677        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 678                          "Link %s is dereferenced\n",
 679                          acpi_device_bid(link->device)));
 680
 681        if (link->refcnt == 0)
 682                acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 683
 684        mutex_unlock(&acpi_link_lock);
 685        return (link->irq.active);
 686}
 687
 688/* --------------------------------------------------------------------------
 689                                 Driver Interface
 690   -------------------------------------------------------------------------- */
 691
 692static int acpi_pci_link_add(struct acpi_device *device,
 693                             const struct acpi_device_id *not_used)
 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(KERN_CONT " *%d", link->irq.possible[i]);
 722                        found = 1;
 723                } else
 724                        printk(KERN_CONT " %d", link->irq.possible[i]);
 725        }
 726
 727        printk(KERN_CONT ")");
 728
 729        if (!found)
 730                printk(KERN_CONT " *%d", link->irq.active);
 731
 732        if (!link->device->status.enabled)
 733                printk(KERN_CONT ", disabled.");
 734
 735        printk(KERN_CONT "\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 < 0 ? result : 1;
 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 void irqrouter_resume(void)
 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}
 766
 767static void acpi_pci_link_remove(struct acpi_device *device)
 768{
 769        struct acpi_pci_link *link;
 770
 771        link = acpi_driver_data(device);
 772
 773        mutex_lock(&acpi_link_lock);
 774        list_del(&link->list);
 775        mutex_unlock(&acpi_link_lock);
 776
 777        kfree(link);
 778}
 779
 780/*
 781 * modify acpi_irq_penalty[] from cmdline
 782 */
 783static int __init acpi_irq_penalty_update(char *str, int used)
 784{
 785        int i;
 786
 787        for (i = 0; i < 16; i++) {
 788                int retval;
 789                int irq;
 790
 791                retval = get_option(&str, &irq);
 792
 793                if (!retval)
 794                        break;  /* no number found */
 795
 796                if (irq < 0)
 797                        continue;
 798
 799                if (irq >= ARRAY_SIZE(acpi_irq_penalty))
 800                        continue;
 801
 802                if (used)
 803                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 804                else
 805                        acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 806
 807                if (retval != 2)        /* no next number */
 808                        break;
 809        }
 810        return 1;
 811}
 812
 813/*
 814 * We'd like PNP to call this routine for the
 815 * single ISA_USED value for each legacy device.
 816 * But instead it calls us with each POSSIBLE setting.
 817 * There is no ISA_POSSIBLE weight, so we simply use
 818 * the (small) PCI_USING penalty.
 819 */
 820void acpi_penalize_isa_irq(int irq, int active)
 821{
 822        if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 823                if (active)
 824                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 825                else
 826                        acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 827        }
 828}
 829
 830bool acpi_isa_irq_available(int irq)
 831{
 832        return irq >= 0 && (irq >= ARRAY_SIZE(acpi_irq_penalty) ||
 833                            acpi_irq_penalty[irq] < PIRQ_PENALTY_ISA_ALWAYS);
 834}
 835
 836/*
 837 * Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict with
 838 * PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be use for
 839 * PCI IRQs.
 840 */
 841void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 842{
 843        if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 844                if (trigger != ACPI_MADT_TRIGGER_LEVEL ||
 845                    polarity != ACPI_MADT_POLARITY_ACTIVE_LOW)
 846                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_ALWAYS;
 847                else
 848                        acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 849        }
 850}
 851
 852/*
 853 * Over-ride default table to reserve additional IRQs for use by ISA
 854 * e.g. acpi_irq_isa=5
 855 * Useful for telling ACPI how not to interfere with your ISA sound card.
 856 */
 857static int __init acpi_irq_isa(char *str)
 858{
 859        return acpi_irq_penalty_update(str, 1);
 860}
 861
 862__setup("acpi_irq_isa=", acpi_irq_isa);
 863
 864/*
 865 * Over-ride default table to free additional IRQs for use by PCI
 866 * e.g. acpi_irq_pci=7,15
 867 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 868 */
 869static int __init acpi_irq_pci(char *str)
 870{
 871        return acpi_irq_penalty_update(str, 0);
 872}
 873
 874__setup("acpi_irq_pci=", acpi_irq_pci);
 875
 876static int __init acpi_irq_nobalance_set(char *str)
 877{
 878        acpi_irq_balance = 0;
 879        return 1;
 880}
 881
 882__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 883
 884static int __init acpi_irq_balance_set(char *str)
 885{
 886        acpi_irq_balance = 1;
 887        return 1;
 888}
 889
 890__setup("acpi_irq_balance", acpi_irq_balance_set);
 891
 892static struct syscore_ops irqrouter_syscore_ops = {
 893        .resume = irqrouter_resume,
 894};
 895
 896void __init acpi_pci_link_init(void)
 897{
 898        if (acpi_noirq)
 899                return;
 900
 901        if (acpi_irq_balance == -1) {
 902                /* no command line switch: enable balancing in IOAPIC mode */
 903                if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 904                        acpi_irq_balance = 1;
 905                else
 906                        acpi_irq_balance = 0;
 907        }
 908        register_syscore_ops(&irqrouter_syscore_ops);
 909        acpi_scan_add_handler(&pci_link_handler);
 910}
 911