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#include <linux/irq.h>
  40
  41#include "internal.h"
  42
  43#define _COMPONENT                      ACPI_PCI_COMPONENT
  44ACPI_MODULE_NAME("pci_link");
  45#define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  46#define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  47#define ACPI_PCI_LINK_FILE_INFO         "info"
  48#define ACPI_PCI_LINK_FILE_STATUS       "state"
  49#define ACPI_PCI_LINK_MAX_POSSIBLE      16
  50
  51static int acpi_pci_link_add(struct acpi_device *device,
  52                             const struct acpi_device_id *not_used);
  53static void acpi_pci_link_remove(struct acpi_device *device);
  54
  55static const struct acpi_device_id link_device_ids[] = {
  56        {"PNP0C0F", 0},
  57        {"", 0},
  58};
  59
  60static struct acpi_scan_handler pci_link_handler = {
  61        .ids = link_device_ids,
  62        .attach = acpi_pci_link_add,
  63        .detach = acpi_pci_link_remove,
  64};
  65
  66/*
  67 * If a link is initialized, we never change its active and initialized
  68 * later even the link is disable. Instead, we just repick the active irq
  69 */
  70struct acpi_pci_link_irq {
  71        u32 active;             /* Current IRQ */
  72        u8 triggering;          /* All IRQs */
  73        u8 polarity;            /* All IRQs */
  74        u8 resource_type;
  75        u8 possible_count;
  76        u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  77        u8 initialized:1;
  78        u8 reserved:7;
  79};
  80
  81struct acpi_pci_link {
  82        struct list_head                list;
  83        struct acpi_device              *device;
  84        struct acpi_pci_link_irq        irq;
  85        int                             refcnt;
  86};
  87
  88static LIST_HEAD(acpi_link_list);
  89static DEFINE_MUTEX(acpi_link_lock);
  90static int sci_irq = -1, sci_penalty;
  91
  92/* --------------------------------------------------------------------------
  93                            PCI Link Device Management
  94   -------------------------------------------------------------------------- */
  95
  96/*
  97 * set context (link) possible list from resource list
  98 */
  99static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
 100                                                void *context)
 101{
 102        struct acpi_pci_link *link = context;
 103        u32 i;
 104
 105        switch (resource->type) {
 106        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 107        case ACPI_RESOURCE_TYPE_END_TAG:
 108                return AE_OK;
 109        case ACPI_RESOURCE_TYPE_IRQ:
 110                {
 111                        struct acpi_resource_irq *p = &resource->data.irq;
 112                        if (!p || !p->interrupt_count) {
 113                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 114                                                  "Blank _PRS IRQ resource\n"));
 115                                return AE_OK;
 116                        }
 117                        for (i = 0;
 118                             (i < p->interrupt_count
 119                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 120                                if (!p->interrupts[i]) {
 121                                        printk(KERN_WARNING PREFIX
 122                                               "Invalid _PRS IRQ %d\n",
 123                                               p->interrupts[i]);
 124                                        continue;
 125                                }
 126                                link->irq.possible[i] = p->interrupts[i];
 127                                link->irq.possible_count++;
 128                        }
 129                        link->irq.triggering = p->triggering;
 130                        link->irq.polarity = p->polarity;
 131                        link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 132                        break;
 133                }
 134        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 135                {
 136                        struct acpi_resource_extended_irq *p =
 137                            &resource->data.extended_irq;
 138                        if (!p || !p->interrupt_count) {
 139                                printk(KERN_WARNING PREFIX
 140                                              "Blank _PRS EXT IRQ resource\n");
 141                                return AE_OK;
 142                        }
 143                        for (i = 0;
 144                             (i < p->interrupt_count
 145                              && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 146                                if (!p->interrupts[i]) {
 147                                        printk(KERN_WARNING PREFIX
 148                                               "Invalid _PRS IRQ %d\n",
 149                                               p->interrupts[i]);
 150                                        continue;
 151                                }
 152                                link->irq.possible[i] = p->interrupts[i];
 153                                link->irq.possible_count++;
 154                        }
 155                        link->irq.triggering = p->triggering;
 156                        link->irq.polarity = p->polarity;
 157                        link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 158                        break;
 159                }
 160        default:
 161                printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 162                       resource->type);
 163                return AE_OK;
 164        }
 165
 166        return AE_CTRL_TERMINATE;
 167}
 168
 169static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 170{
 171        acpi_status status;
 172
 173        status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 174                                     acpi_pci_link_check_possible, link);
 175        if (ACPI_FAILURE(status)) {
 176                acpi_handle_debug(link->device->handle, "_PRS not present or invalid");
 177                return 0;
 178        }
 179
 180        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 181                          "Found %d possible IRQs\n",
 182                          link->irq.possible_count));
 183
 184        return 0;
 185}
 186
 187static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 188                                               void *context)
 189{
 190        int *irq = context;
 191
 192        switch (resource->type) {
 193        case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 194        case ACPI_RESOURCE_TYPE_END_TAG:
 195                return AE_OK;
 196        case ACPI_RESOURCE_TYPE_IRQ:
 197                {
 198                        struct acpi_resource_irq *p = &resource->data.irq;
 199                        if (!p || !p->interrupt_count) {
 200                                /*
 201                                 * IRQ descriptors may have no IRQ# bits set,
 202                                 * particularly those those w/ _STA disabled
 203                                 */
 204                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 205                                                  "Blank _CRS IRQ resource\n"));
 206                                return AE_OK;
 207                        }
 208                        *irq = p->interrupts[0];
 209                        break;
 210                }
 211        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 212                {
 213                        struct acpi_resource_extended_irq *p =
 214                            &resource->data.extended_irq;
 215                        if (!p || !p->interrupt_count) {
 216                                /*
 217                                 * extended IRQ descriptors must
 218                                 * return at least 1 IRQ
 219                                 */
 220                                printk(KERN_WARNING PREFIX
 221                                              "Blank _CRS EXT IRQ resource\n");
 222                                return AE_OK;
 223                        }
 224                        *irq = p->interrupts[0];
 225                        break;
 226                }
 227                break;
 228        default:
 229                printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 230                       resource->type);
 231                return AE_OK;
 232        }
 233
 234        return AE_CTRL_TERMINATE;
 235}
 236
 237/*
 238 * Run _CRS and set link->irq.active
 239 *
 240 * return value:
 241 * 0 - success
 242 * !0 - failure
 243 */
 244static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 245{
 246        int result = 0;
 247        acpi_status status;
 248        int irq = 0;
 249
 250        link->irq.active = 0;
 251
 252        /* in practice, status disabled is meaningless, ignore it */
 253        if (acpi_strict) {
 254                /* Query _STA, set link->device->status */
 255                result = acpi_bus_get_status(link->device);
 256                if (result) {
 257                        printk(KERN_ERR PREFIX "Unable to read status\n");
 258                        goto end;
 259                }
 260
 261                if (!link->device->status.enabled) {
 262                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 263                        return 0;
 264                }
 265        }
 266
 267        /* 
 268         * Query and parse _CRS to get the current IRQ assignment. 
 269         */
 270
 271        status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 272                                     acpi_pci_link_check_current, &irq);
 273        if (ACPI_FAILURE(status)) {
 274                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 275                result = -ENODEV;
 276                goto end;
 277        }
 278
 279        if (acpi_strict && !irq) {
 280                printk(KERN_ERR PREFIX "_CRS returned 0\n");
 281                result = -ENODEV;
 282        }
 283
 284        link->irq.active = irq;
 285
 286        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 287
 288      end:
 289        return result;
 290}
 291
 292static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 293{
 294        int result;
 295        acpi_status status;
 296        struct {
 297                struct acpi_resource res;
 298                struct acpi_resource end;
 299        } *resource;
 300        struct acpi_buffer buffer = { 0, NULL };
 301
 302        if (!irq)
 303                return -EINVAL;
 304
 305        resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 306        if (!resource)
 307                return -ENOMEM;
 308
 309        buffer.length = sizeof(*resource) + 1;
 310        buffer.pointer = resource;
 311
 312        switch (link->irq.resource_type) {
 313        case ACPI_RESOURCE_TYPE_IRQ:
 314                resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 315                resource->res.length = sizeof(struct acpi_resource);
 316                resource->res.data.irq.triggering = link->irq.triggering;
 317                resource->res.data.irq.polarity =
 318                    link->irq.polarity;
 319                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 320                        resource->res.data.irq.sharable =
 321                            ACPI_EXCLUSIVE;
 322                else
 323                        resource->res.data.irq.sharable = ACPI_SHARED;
 324                resource->res.data.irq.interrupt_count = 1;
 325                resource->res.data.irq.interrupts[0] = irq;
 326                break;
 327
 328        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 329                resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 330                resource->res.length = sizeof(struct acpi_resource);
 331                resource->res.data.extended_irq.producer_consumer =
 332                    ACPI_CONSUMER;
 333                resource->res.data.extended_irq.triggering =
 334                    link->irq.triggering;
 335                resource->res.data.extended_irq.polarity =
 336                    link->irq.polarity;
 337                if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 338                        resource->res.data.irq.sharable =
 339                            ACPI_EXCLUSIVE;
 340                else
 341                        resource->res.data.irq.sharable = ACPI_SHARED;
 342                resource->res.data.extended_irq.interrupt_count = 1;
 343                resource->res.data.extended_irq.interrupts[0] = irq;
 344                /* ignore resource_source, it's optional */
 345                break;
 346        default:
 347                printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 348                result = -EINVAL;
 349                goto end;
 350
 351        }
 352        resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 353        resource->end.length = sizeof(struct acpi_resource);
 354
 355        /* Attempt to set the resource */
 356        status = acpi_set_current_resources(link->device->handle, &buffer);
 357
 358        /* check for total failure */
 359        if (ACPI_FAILURE(status)) {
 360                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 361                result = -ENODEV;
 362                goto end;
 363        }
 364
 365        /* Query _STA, set device->status */
 366        result = acpi_bus_get_status(link->device);
 367        if (result) {
 368                printk(KERN_ERR PREFIX "Unable to read status\n");
 369                goto end;
 370        }
 371        if (!link->device->status.enabled) {
 372                printk(KERN_WARNING PREFIX
 373                              "%s [%s] disabled and referenced, BIOS bug\n",
 374                              acpi_device_name(link->device),
 375                              acpi_device_bid(link->device));
 376        }
 377
 378        /* Query _CRS, set link->irq.active */
 379        result = acpi_pci_link_get_current(link);
 380        if (result) {
 381                goto end;
 382        }
 383
 384        /*
 385         * Is current setting not what we set?
 386         * set link->irq.active
 387         */
 388        if (link->irq.active != irq) {
 389                /*
 390                 * policy: when _CRS doesn't return what we just _SRS
 391                 * assume _SRS worked and override _CRS value.
 392                 */
 393                printk(KERN_WARNING PREFIX
 394                              "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 395                              acpi_device_name(link->device),
 396                              acpi_device_bid(link->device), link->irq.active, irq);
 397                link->irq.active = irq;
 398        }
 399
 400        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 401
 402      end:
 403        kfree(resource);
 404        return result;
 405}
 406
 407/* --------------------------------------------------------------------------
 408                            PCI Link IRQ Management
 409   -------------------------------------------------------------------------- */
 410
 411/*
 412 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 413 * Link Devices to move the PIRQs around to minimize sharing.
 414 * 
 415 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 416 * that the BIOS has already set to active.  This is necessary because
 417 * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 418 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 419 * even if acpi_irq_nobalance is set.
 420 *
 421 * A tables of penalties avoids directing PCI interrupts to well known
 422 * ISA IRQs. Boot params are available to over-ride the default table:
 423 *
 424 * List interrupts that are free for PCI use.
 425 * acpi_irq_pci=n[,m]
 426 *
 427 * List interrupts that should not be used for PCI:
 428 * acpi_irq_isa=n[,m]
 429 *
 430 * Note that PCI IRQ routers have a list of possible IRQs,
 431 * which may not include the IRQs this table says are available.
 432 * 
 433 * Since this heuristic can't tell the difference between a link
 434 * that no device will attach to, vs. a link which may be shared
 435 * by multiple active devices -- it is not optimal.
 436 *
 437 * If interrupt performance is that important, get an IO-APIC system
 438 * with a pin dedicated to each device.  Or for that matter, an MSI
 439 * enabled system.
 440 */
 441
 442#define ACPI_MAX_ISA_IRQS       16
 443
 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_isa_irq_penalty[ACPI_MAX_ISA_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        0,                              /* IRQ9  PCI, often acpi */
 461        0,                              /* IRQ10 PCI */
 462        0,                              /* 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
 470static int acpi_irq_pci_sharing_penalty(int irq)
 471{
 472        struct acpi_pci_link *link;
 473        int penalty = 0;
 474        int i;
 475
 476        list_for_each_entry(link, &acpi_link_list, list) {
 477                /*
 478                 * If a link is active, penalize its IRQ heavily
 479                 * so we try to choose a different IRQ.
 480                 */
 481                if (link->irq.active && link->irq.active == irq)
 482                        penalty += PIRQ_PENALTY_PCI_USING;
 483
 484                /*
 485                 * penalize the IRQs PCI might use, but not as severely.
 486                 */
 487                for (i = 0; i < link->irq.possible_count; i++)
 488                        if (link->irq.possible[i] == irq)
 489                                penalty += PIRQ_PENALTY_PCI_POSSIBLE /
 490                                        link->irq.possible_count;
 491        }
 492
 493        return penalty;
 494}
 495
 496static int acpi_irq_get_penalty(int irq)
 497{
 498        int penalty = 0;
 499
 500        if (irq == sci_irq)
 501                penalty += sci_penalty;
 502
 503        if (irq < ACPI_MAX_ISA_IRQS)
 504                return penalty + acpi_isa_irq_penalty[irq];
 505
 506        return penalty + acpi_irq_pci_sharing_penalty(irq);
 507}
 508
 509int __init acpi_irq_penalty_init(void)
 510{
 511        struct acpi_pci_link *link;
 512        int i;
 513
 514        /*
 515         * Update penalties to facilitate IRQ balancing.
 516         */
 517        list_for_each_entry(link, &acpi_link_list, list) {
 518
 519                /*
 520                 * reflect the possible and active irqs in the penalty table --
 521                 * useful for breaking ties.
 522                 */
 523                if (link->irq.possible_count) {
 524                        int penalty =
 525                            PIRQ_PENALTY_PCI_POSSIBLE /
 526                            link->irq.possible_count;
 527
 528                        for (i = 0; i < link->irq.possible_count; i++) {
 529                                if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
 530                                        acpi_isa_irq_penalty[link->irq.
 531                                                         possible[i]] +=
 532                                            penalty;
 533                        }
 534
 535                } else if (link->irq.active &&
 536                                (link->irq.active < ACPI_MAX_ISA_IRQS)) {
 537                        acpi_isa_irq_penalty[link->irq.active] +=
 538                            PIRQ_PENALTY_PCI_POSSIBLE;
 539                }
 540        }
 541
 542        return 0;
 543}
 544
 545static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 546
 547static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 548{
 549        int irq;
 550        int i;
 551
 552        if (link->irq.initialized) {
 553                if (link->refcnt == 0)
 554                        /* This means the link is disabled but initialized */
 555                        acpi_pci_link_set(link, link->irq.active);
 556                return 0;
 557        }
 558
 559        /*
 560         * search for active IRQ in list of possible IRQs.
 561         */
 562        for (i = 0; i < link->irq.possible_count; ++i) {
 563                if (link->irq.active == link->irq.possible[i])
 564                        break;
 565        }
 566        /*
 567         * forget active IRQ that is not in possible list
 568         */
 569        if (i == link->irq.possible_count) {
 570                if (acpi_strict)
 571                        printk(KERN_WARNING PREFIX "_CRS %d not found"
 572                                      " in _PRS\n", link->irq.active);
 573                link->irq.active = 0;
 574        }
 575
 576        /*
 577         * if active found, use it; else pick entry from end of possible list.
 578         */
 579        if (link->irq.active)
 580                irq = link->irq.active;
 581        else
 582                irq = link->irq.possible[link->irq.possible_count - 1];
 583
 584        if (acpi_irq_balance || !link->irq.active) {
 585                /*
 586                 * Select the best IRQ.  This is done in reverse to promote
 587                 * the use of IRQs 9, 10, 11, and >15.
 588                 */
 589                for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 590                        if (acpi_irq_get_penalty(irq) >
 591                            acpi_irq_get_penalty(link->irq.possible[i]))
 592                                irq = link->irq.possible[i];
 593                }
 594        }
 595        if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
 596                printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
 597                            "Try pci=noacpi or acpi=off\n",
 598                            acpi_device_name(link->device),
 599                            acpi_device_bid(link->device));
 600                return -ENODEV;
 601        }
 602
 603        /* Attempt to enable the link device at this IRQ. */
 604        if (acpi_pci_link_set(link, irq)) {
 605                printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 606                            "Try pci=noacpi or acpi=off\n",
 607                            acpi_device_name(link->device),
 608                            acpi_device_bid(link->device));
 609                return -ENODEV;
 610        } else {
 611                if (link->irq.active < ACPI_MAX_ISA_IRQS)
 612                        acpi_isa_irq_penalty[link->irq.active] +=
 613                                PIRQ_PENALTY_PCI_USING;
 614
 615                pr_info("%s [%s] enabled at IRQ %d\n",
 616                       acpi_device_name(link->device),
 617                       acpi_device_bid(link->device), link->irq.active);
 618        }
 619
 620        link->irq.initialized = 1;
 621        return 0;
 622}
 623
 624/*
 625 * acpi_pci_link_allocate_irq
 626 * success: return IRQ >= 0
 627 * failure: return -1
 628 */
 629int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 630                               int *polarity, char **name)
 631{
 632        int result;
 633        struct acpi_device *device;
 634        struct acpi_pci_link *link;
 635
 636        result = acpi_bus_get_device(handle, &device);
 637        if (result) {
 638                printk(KERN_ERR PREFIX "Invalid link device\n");
 639                return -1;
 640        }
 641
 642        link = acpi_driver_data(device);
 643        if (!link) {
 644                printk(KERN_ERR PREFIX "Invalid link context\n");
 645                return -1;
 646        }
 647
 648        /* TBD: Support multiple index (IRQ) entries per Link Device */
 649        if (index) {
 650                printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 651                return -1;
 652        }
 653
 654        mutex_lock(&acpi_link_lock);
 655        if (acpi_pci_link_allocate(link)) {
 656                mutex_unlock(&acpi_link_lock);
 657                return -1;
 658        }
 659
 660        if (!link->irq.active) {
 661                mutex_unlock(&acpi_link_lock);
 662                printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 663                return -1;
 664        }
 665        link->refcnt++;
 666        mutex_unlock(&acpi_link_lock);
 667
 668        if (triggering)
 669                *triggering = link->irq.triggering;
 670        if (polarity)
 671                *polarity = link->irq.polarity;
 672        if (name)
 673                *name = acpi_device_bid(link->device);
 674        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 675                          "Link %s is referenced\n",
 676                          acpi_device_bid(link->device)));
 677        return (link->irq.active);
 678}
 679
 680/*
 681 * We don't change link's irq information here.  After it is reenabled, we
 682 * continue use the info
 683 */
 684int acpi_pci_link_free_irq(acpi_handle handle)
 685{
 686        struct acpi_device *device;
 687        struct acpi_pci_link *link;
 688        acpi_status result;
 689
 690        result = acpi_bus_get_device(handle, &device);
 691        if (result) {
 692                printk(KERN_ERR PREFIX "Invalid link device\n");
 693                return -1;
 694        }
 695
 696        link = acpi_driver_data(device);
 697        if (!link) {
 698                printk(KERN_ERR PREFIX "Invalid link context\n");
 699                return -1;
 700        }
 701
 702        mutex_lock(&acpi_link_lock);
 703        if (!link->irq.initialized) {
 704                mutex_unlock(&acpi_link_lock);
 705                printk(KERN_ERR PREFIX "Link isn't initialized\n");
 706                return -1;
 707        }
 708#ifdef  FUTURE_USE
 709        /*
 710         * The Link reference count allows us to _DISable an unused link
 711         * and suspend time, and set it again  on resume.
 712         * However, 2.6.12 still has irq_router.resume
 713         * which blindly restores the link state.
 714         * So we disable the reference count method
 715         * to prevent duplicate acpi_pci_link_set()
 716         * which would harm some systems
 717         */
 718        link->refcnt--;
 719#endif
 720        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 721                          "Link %s is dereferenced\n",
 722                          acpi_device_bid(link->device)));
 723
 724        if (link->refcnt == 0)
 725                acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 726
 727        mutex_unlock(&acpi_link_lock);
 728        return (link->irq.active);
 729}
 730
 731/* --------------------------------------------------------------------------
 732                                 Driver Interface
 733   -------------------------------------------------------------------------- */
 734
 735static int acpi_pci_link_add(struct acpi_device *device,
 736                             const struct acpi_device_id *not_used)
 737{
 738        int result;
 739        struct acpi_pci_link *link;
 740        int i;
 741        int found = 0;
 742
 743        link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 744        if (!link)
 745                return -ENOMEM;
 746
 747        link->device = device;
 748        strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 749        strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 750        device->driver_data = link;
 751
 752        mutex_lock(&acpi_link_lock);
 753        result = acpi_pci_link_get_possible(link);
 754        if (result)
 755                goto end;
 756
 757        /* query and set link->irq.active */
 758        acpi_pci_link_get_current(link);
 759
 760        printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 761               acpi_device_bid(device));
 762        for (i = 0; i < link->irq.possible_count; i++) {
 763                if (link->irq.active == link->irq.possible[i]) {
 764                        printk(KERN_CONT " *%d", link->irq.possible[i]);
 765                        found = 1;
 766                } else
 767                        printk(KERN_CONT " %d", link->irq.possible[i]);
 768        }
 769
 770        printk(KERN_CONT ")");
 771
 772        if (!found)
 773                printk(KERN_CONT " *%d", link->irq.active);
 774
 775        if (!link->device->status.enabled)
 776                printk(KERN_CONT ", disabled.");
 777
 778        printk(KERN_CONT "\n");
 779
 780        list_add_tail(&link->list, &acpi_link_list);
 781
 782      end:
 783        /* disable all links -- to be activated on use */
 784        acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 785        mutex_unlock(&acpi_link_lock);
 786
 787        if (result)
 788                kfree(link);
 789
 790        return result < 0 ? result : 1;
 791}
 792
 793static int acpi_pci_link_resume(struct acpi_pci_link *link)
 794{
 795        if (link->refcnt && link->irq.active && link->irq.initialized)
 796                return (acpi_pci_link_set(link, link->irq.active));
 797
 798        return 0;
 799}
 800
 801static void irqrouter_resume(void)
 802{
 803        struct acpi_pci_link *link;
 804
 805        list_for_each_entry(link, &acpi_link_list, list) {
 806                acpi_pci_link_resume(link);
 807        }
 808}
 809
 810static void acpi_pci_link_remove(struct acpi_device *device)
 811{
 812        struct acpi_pci_link *link;
 813
 814        link = acpi_driver_data(device);
 815
 816        mutex_lock(&acpi_link_lock);
 817        list_del(&link->list);
 818        mutex_unlock(&acpi_link_lock);
 819
 820        kfree(link);
 821}
 822
 823/*
 824 * modify acpi_isa_irq_penalty[] from cmdline
 825 */
 826static int __init acpi_irq_penalty_update(char *str, int used)
 827{
 828        int i;
 829
 830        for (i = 0; i < 16; i++) {
 831                int retval;
 832                int irq;
 833                int new_penalty;
 834
 835                retval = get_option(&str, &irq);
 836
 837                if (!retval)
 838                        break;  /* no number found */
 839
 840                /* see if this is a ISA IRQ */
 841                if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
 842                        continue;
 843
 844                if (used)
 845                        new_penalty = acpi_isa_irq_penalty[irq] +
 846                                        PIRQ_PENALTY_ISA_USED;
 847                else
 848                        new_penalty = 0;
 849
 850                acpi_isa_irq_penalty[irq] = new_penalty;
 851                if (retval != 2)        /* no next number */
 852                        break;
 853        }
 854        return 1;
 855}
 856
 857/*
 858 * We'd like PNP to call this routine for the
 859 * single ISA_USED value for each legacy device.
 860 * But instead it calls us with each POSSIBLE setting.
 861 * There is no ISA_POSSIBLE weight, so we simply use
 862 * the (small) PCI_USING penalty.
 863 */
 864void acpi_penalize_isa_irq(int irq, int active)
 865{
 866        if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
 867                acpi_isa_irq_penalty[irq] +=
 868                  (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
 869}
 870
 871bool acpi_isa_irq_available(int irq)
 872{
 873        return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
 874                    acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
 875}
 876
 877void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 878{
 879        sci_irq = irq;
 880
 881        if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
 882            polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
 883                sci_penalty = PIRQ_PENALTY_PCI_USING;
 884        else
 885                sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
 886}
 887
 888/*
 889 * Over-ride default table to reserve additional IRQs for use by ISA
 890 * e.g. acpi_irq_isa=5
 891 * Useful for telling ACPI how not to interfere with your ISA sound card.
 892 */
 893static int __init acpi_irq_isa(char *str)
 894{
 895        return acpi_irq_penalty_update(str, 1);
 896}
 897
 898__setup("acpi_irq_isa=", acpi_irq_isa);
 899
 900/*
 901 * Over-ride default table to free additional IRQs for use by PCI
 902 * e.g. acpi_irq_pci=7,15
 903 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 904 */
 905static int __init acpi_irq_pci(char *str)
 906{
 907        return acpi_irq_penalty_update(str, 0);
 908}
 909
 910__setup("acpi_irq_pci=", acpi_irq_pci);
 911
 912static int __init acpi_irq_nobalance_set(char *str)
 913{
 914        acpi_irq_balance = 0;
 915        return 1;
 916}
 917
 918__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 919
 920static int __init acpi_irq_balance_set(char *str)
 921{
 922        acpi_irq_balance = 1;
 923        return 1;
 924}
 925
 926__setup("acpi_irq_balance", acpi_irq_balance_set);
 927
 928static struct syscore_ops irqrouter_syscore_ops = {
 929        .resume = irqrouter_resume,
 930};
 931
 932void __init acpi_pci_link_init(void)
 933{
 934        if (acpi_noirq)
 935                return;
 936
 937        if (acpi_irq_balance == -1) {
 938                /* no command line switch: enable balancing in IOAPIC mode */
 939                if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 940                        acpi_irq_balance = 1;
 941                else
 942                        acpi_irq_balance = 0;
 943        }
 944        register_syscore_ops(&irqrouter_syscore_ops);
 945        acpi_scan_add_handler(&pci_link_handler);
 946}
 947