drivers/acpi/pci_link.c

   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
  43 ACPI_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
  50 static int acpi_pci_link_add(struct acpi_device *device,
  51                              const struct acpi_device_id *not_used);
  52 static void acpi_pci_link_remove(struct acpi_device *device);
  53
  54 static const struct acpi_device_id link_device_ids[] = {
  55         {"PNP0C0F", 0},
  56         {"", 0},
  57 };
  58
  59 static 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  */
  69 struct acpi_pci_link_irq {
  70         u8 active;              /* Current IRQ */
  71         u8 triggering;          /* All IRQs */
  72         u8 polarity;            /* All IRQs */
  73         u8 resource_type;
  74         u8 possible_count;
  75         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  76         u8 initialized:1;
  77         u8 reserved:7;
  78 };
  79
  80 struct 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
  87 static LIST_HEAD(acpi_link_list);
  88 static 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  */
  97 static 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
 167 static 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
 185 static 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  */
 242 static 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
 290 static 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
 450 static 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
 470 int __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         /* Add a penalty for the SCI */
 502         acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
 503         return 0;
 504 }
 505
 506 static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 507
 508 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 509 {
 510         int irq;
 511         int i;
 512
 513         if (link->irq.initialized) {
 514                 if (link->refcnt == 0)
 515                         /* This means the link is disabled but initialized */
 516                         acpi_pci_link_set(link, link->irq.active);
 517                 return 0;
 518         }
 519
 520         /*
 521          * search for active IRQ in list of possible IRQs.
 522          */
 523         for (i = 0; i < link->irq.possible_count; ++i) {
 524                 if (link->irq.active == link->irq.possible[i])
 525                         break;
 526         }
 527         /*
 528          * forget active IRQ that is not in possible list
 529          */
 530         if (i == link->irq.possible_count) {
 531                 if (acpi_strict)
 532                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 533                                       " in _PRS\n", link->irq.active);
 534                 link->irq.active = 0;
 535         }
 536
 537         /*
 538          * if active found, use it; else pick entry from end of possible list.
 539          */
 540         if (link->irq.active)
 541                 irq = link->irq.active;
 542         else
 543                 irq = link->irq.possible[link->irq.possible_count - 1];
 544
 545         if (acpi_irq_balance || !link->irq.active) {
 546                 /*
 547                  * Select the best IRQ.  This is done in reverse to promote
 548                  * the use of IRQs 9, 10, 11, and >15.
 549                  */
 550                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 551                         if (acpi_irq_penalty[irq] >
 552                             acpi_irq_penalty[link->irq.possible[i]])
 553                                 irq = link->irq.possible[i];
 554                 }
 555         }
 556
 557         /* Attempt to enable the link device at this IRQ. */
 558         if (acpi_pci_link_set(link, irq)) {
 559                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 560                             "Try pci=noacpi or acpi=off\n",
 561                             acpi_device_name(link->device),
 562                             acpi_device_bid(link->device));
 563                 return -ENODEV;
 564         } else {
 565                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 566                 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
 567                        acpi_device_name(link->device),
 568                        acpi_device_bid(link->device), link->irq.active);
 569         }
 570
 571         link->irq.initialized = 1;
 572         return 0;
 573 }
 574
 575 /*
 576  * acpi_pci_link_allocate_irq
 577  * success: return IRQ >= 0
 578  * failure: return -1
 579  */
 580 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 581                                int *polarity, char **name)
 582 {
 583         int result;
 584         struct acpi_device *device;
 585         struct acpi_pci_link *link;
 586
 587         result = acpi_bus_get_device(handle, &device);
 588         if (result) {
 589                 printk(KERN_ERR PREFIX "Invalid link device\n");
 590                 return -1;
 591         }
 592
 593         link = acpi_driver_data(device);
 594         if (!link) {
 595                 printk(KERN_ERR PREFIX "Invalid link context\n");
 596                 return -1;
 597         }
 598
 599         /* TBD: Support multiple index (IRQ) entries per Link Device */
 600         if (index) {
 601                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 602                 return -1;
 603         }
 604
 605         mutex_lock(&acpi_link_lock);
 606         if (acpi_pci_link_allocate(link)) {
 607                 mutex_unlock(&acpi_link_lock);
 608                 return -1;
 609         }
 610
 611         if (!link->irq.active) {
 612                 mutex_unlock(&acpi_link_lock);
 613                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 614                 return -1;
 615         }
 616         link->refcnt++;
 617         mutex_unlock(&acpi_link_lock);
 618
 619         if (triggering)
 620                 *triggering = link->irq.triggering;
 621         if (polarity)
 622                 *polarity = link->irq.polarity;
 623         if (name)
 624                 *name = acpi_device_bid(link->device);
 625         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 626                           "Link %s is referenced\n",
 627                           acpi_device_bid(link->device)));
 628         return (link->irq.active);
 629 }
 630
 631 /*
 632  * We don't change link's irq information here.  After it is reenabled, we
 633  * continue use the info
 634  */
 635 int acpi_pci_link_free_irq(acpi_handle handle)
 636 {
 637         struct acpi_device *device;
 638         struct acpi_pci_link *link;
 639         acpi_status result;
 640
 641         result = acpi_bus_get_device(handle, &device);
 642         if (result) {
 643                 printk(KERN_ERR PREFIX "Invalid link device\n");
 644                 return -1;
 645         }
 646
 647         link = acpi_driver_data(device);
 648         if (!link) {
 649                 printk(KERN_ERR PREFIX "Invalid link context\n");
 650                 return -1;
 651         }
 652
 653         mutex_lock(&acpi_link_lock);
 654         if (!link->irq.initialized) {
 655                 mutex_unlock(&acpi_link_lock);
 656                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 657                 return -1;
 658         }
 659 #ifdef  FUTURE_USE
 660         /*
 661          * The Link reference count allows us to _DISable an unused link
 662          * and suspend time, and set it again  on resume.
 663          * However, 2.6.12 still has irq_router.resume
 664          * which blindly restores the link state.
 665          * So we disable the reference count method
 666          * to prevent duplicate acpi_pci_link_set()
 667          * which would harm some systems
 668          */
 669         link->refcnt--;
 670 #endif
 671         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 672                           "Link %s is dereferenced\n",
 673                           acpi_device_bid(link->device)));
 674
 675         if (link->refcnt == 0)
 676                 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 677
 678         mutex_unlock(&acpi_link_lock);
 679         return (link->irq.active);
 680 }
 681
 682 /* --------------------------------------------------------------------------
 683                                  Driver Interface
 684    -------------------------------------------------------------------------- */
 685
 686 static int acpi_pci_link_add(struct acpi_device *device,
 687                              const struct acpi_device_id *not_used)
 688 {
 689         int result;
 690         struct acpi_pci_link *link;
 691         int i;
 692         int found = 0;
 693
 694         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 695         if (!link)
 696                 return -ENOMEM;
 697
 698         link->device = device;
 699         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 700         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 701         device->driver_data = link;
 702
 703         mutex_lock(&acpi_link_lock);
 704         result = acpi_pci_link_get_possible(link);
 705         if (result)
 706                 goto end;
 707
 708         /* query and set link->irq.active */
 709         acpi_pci_link_get_current(link);
 710
 711         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 712                acpi_device_bid(device));
 713         for (i = 0; i < link->irq.possible_count; i++) {
 714                 if (link->irq.active == link->irq.possible[i]) {
 715                         printk(KERN_CONT " *%d", link->irq.possible[i]);
 716                         found = 1;
 717                 } else
 718                         printk(KERN_CONT " %d", link->irq.possible[i]);
 719         }
 720
 721         printk(KERN_CONT ")");
 722
 723         if (!found)
 724                 printk(KERN_CONT " *%d", link->irq.active);
 725
 726         if (!link->device->status.enabled)
 727                 printk(KERN_CONT ", disabled.");
 728
 729         printk(KERN_CONT "\n");
 730
 731         list_add_tail(&link->list, &acpi_link_list);
 732
 733       end:
 734         /* disable all links -- to be activated on use */
 735         acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 736         mutex_unlock(&acpi_link_lock);
 737
 738         if (result)
 739                 kfree(link);
 740
 741         return result < 0 ? result : 1;
 742 }
 743
 744 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 745 {
 746         if (link->refcnt && link->irq.active && link->irq.initialized)
 747                 return (acpi_pci_link_set(link, link->irq.active));
 748
 749         return 0;
 750 }
 751
 752 static void irqrouter_resume(void)
 753 {
 754         struct acpi_pci_link *link;
 755
 756         list_for_each_entry(link, &acpi_link_list, list) {
 757                 acpi_pci_link_resume(link);
 758         }
 759 }
 760
 761 static void acpi_pci_link_remove(struct acpi_device *device)
 762 {
 763         struct acpi_pci_link *link;
 764
 765         link = acpi_driver_data(device);
 766
 767         mutex_lock(&acpi_link_lock);
 768         list_del(&link->list);
 769         mutex_unlock(&acpi_link_lock);
 770
 771         kfree(link);
 772 }
 773
 774 /*
 775  * modify acpi_irq_penalty[] from cmdline
 776  */
 777 static int __init acpi_irq_penalty_update(char *str, int used)
 778 {
 779         int i;
 780
 781         for (i = 0; i < 16; i++) {
 782                 int retval;
 783                 int irq;
 784
 785                 retval = get_option(&str, &irq);
 786
 787                 if (!retval)
 788                         break;  /* no number found */
 789
 790                 if (irq < 0)
 791                         continue;
 792
 793                 if (irq >= ARRAY_SIZE(acpi_irq_penalty))
 794                         continue;
 795
 796                 if (used)
 797                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 798                 else
 799                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 800
 801                 if (retval != 2)        /* no next number */
 802                         break;
 803         }
 804         return 1;
 805 }
 806
 807 /*
 808  * We'd like PNP to call this routine for the
 809  * single ISA_USED value for each legacy device.
 810  * But instead it calls us with each POSSIBLE setting.
 811  * There is no ISA_POSSIBLE weight, so we simply use
 812  * the (small) PCI_USING penalty.
 813  */
 814 void acpi_penalize_isa_irq(int irq, int active)
 815 {
 816         if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 817                 if (active)
 818                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 819                 else
 820                         acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 821         }
 822 }
 823
 824 /*
 825  * Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict with
 826  * PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be use for
 827  * PCI IRQs.
 828  */
 829 void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 830 {
 831         if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 832                 if (trigger != ACPI_MADT_TRIGGER_LEVEL ||
 833                     polarity != ACPI_MADT_POLARITY_ACTIVE_LOW)
 834                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_ALWAYS;
 835                 else
 836                         acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 837         }
 838 }
 839
 840 /*
 841  * Over-ride default table to reserve additional IRQs for use by ISA
 842  * e.g. acpi_irq_isa=5
 843  * Useful for telling ACPI how not to interfere with your ISA sound card.
 844  */
 845 static int __init acpi_irq_isa(char *str)
 846 {
 847         return acpi_irq_penalty_update(str, 1);
 848 }
 849
 850 __setup("acpi_irq_isa=", acpi_irq_isa);
 851
 852 /*
 853  * Over-ride default table to free additional IRQs for use by PCI
 854  * e.g. acpi_irq_pci=7,15
 855  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 856  */
 857 static int __init acpi_irq_pci(char *str)
 858 {
 859         return acpi_irq_penalty_update(str, 0);
 860 }
 861
 862 __setup("acpi_irq_pci=", acpi_irq_pci);
 863
 864 static int __init acpi_irq_nobalance_set(char *str)
 865 {
 866         acpi_irq_balance = 0;
 867         return 1;
 868 }
 869
 870 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 871
 872 static int __init acpi_irq_balance_set(char *str)
 873 {
 874         acpi_irq_balance = 1;
 875         return 1;
 876 }
 877
 878 __setup("acpi_irq_balance", acpi_irq_balance_set);
 879
 880 static struct syscore_ops irqrouter_syscore_ops = {
 881         .resume = irqrouter_resume,
 882 };
 883
 884 void __init acpi_pci_link_init(void)
 885 {
 886         if (acpi_noirq)
 887                 return;
 888
 889         if (acpi_irq_balance == -1) {
 890                 /* no command line switch: enable balancing in IOAPIC mode */
 891                 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 892                         acpi_irq_balance = 1;
 893                 else
 894                         acpi_irq_balance = 0;
 895         }
 896         register_syscore_ops(&irqrouter_syscore_ops);
 897         acpi_scan_add_handler(&pci_link_handler);
 898 }