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  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  *
  26  * TBD:
  27  *      1. Support more than one IRQ resource entry per link device (index).
  28  *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  29  *         for IRQ management (e.g. start()->_SRS).
  30  */
  31
  32 #include <linux/sysdev.h>
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/types.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/pm.h>
  40 #include <linux/pci.h>
  41 #include <linux/mutex.h>
  42 #include <linux/slab.h>
  43
  44 #include <acpi/acpi_bus.h>
  45 #include <acpi/acpi_drivers.h>
  46
  47 #define PREFIX "ACPI: "
  48
  49 #define _COMPONENT                      ACPI_PCI_COMPONENT
  50 ACPI_MODULE_NAME("pci_link");
  51 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  52 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  53 #define ACPI_PCI_LINK_FILE_INFO         "info"
  54 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  55 #define ACPI_PCI_LINK_MAX_POSSIBLE      16
  56
  57 static int acpi_pci_link_add(struct acpi_device *device);
  58 static int acpi_pci_link_remove(struct acpi_device *device, int type);
  59
  60 static const struct acpi_device_id link_device_ids[] = {
  61         {"PNP0C0F", 0},
  62         {"", 0},
  63 };
  64 MODULE_DEVICE_TABLE(acpi, link_device_ids);
  65
  66 static struct acpi_driver acpi_pci_link_driver = {
  67         .name = "pci_link",
  68         .class = ACPI_PCI_LINK_CLASS,
  69         .ids = link_device_ids,
  70         .ops = {
  71                 .add = acpi_pci_link_add,
  72                 .remove = acpi_pci_link_remove,
  73         },
  74 };
  75
  76 /*
  77  * If a link is initialized, we never change its active and initialized
  78  * later even the link is disable. Instead, we just repick the active irq
  79  */
  80 struct acpi_pci_link_irq {
  81         u8 active;              /* Current IRQ */
  82         u8 triggering;          /* All IRQs */
  83         u8 polarity;            /* All IRQs */
  84         u8 resource_type;
  85         u8 possible_count;
  86         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  87         u8 initialized:1;
  88         u8 reserved:7;
  89 };
  90
  91 struct acpi_pci_link {
  92         struct list_head                list;
  93         struct acpi_device              *device;
  94         struct acpi_pci_link_irq        irq;
  95         int                             refcnt;
  96 };
  97
  98 static LIST_HEAD(acpi_link_list);
  99 static DEFINE_MUTEX(acpi_link_lock);
 100
 101 /* --------------------------------------------------------------------------
 102                             PCI Link Device Management
 103    -------------------------------------------------------------------------- */
 104
 105 /*
 106  * set context (link) possible list from resource list
 107  */
 108 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
 109                                                 void *context)
 110 {
 111         struct acpi_pci_link *link = context;
 112         u32 i;
 113
 114         switch (resource->type) {
 115         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 116         case ACPI_RESOURCE_TYPE_END_TAG:
 117                 return AE_OK;
 118         case ACPI_RESOURCE_TYPE_IRQ:
 119                 {
 120                         struct acpi_resource_irq *p = &resource->data.irq;
 121                         if (!p || !p->interrupt_count) {
 122                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 123                                                   "Blank _PRS IRQ resource\n"));
 124                                 return AE_OK;
 125                         }
 126                         for (i = 0;
 127                              (i < p->interrupt_count
 128                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 129                                 if (!p->interrupts[i]) {
 130                                         printk(KERN_WARNING PREFIX
 131                                                "Invalid _PRS IRQ %d\n",
 132                                                p->interrupts[i]);
 133                                         continue;
 134                                 }
 135                                 link->irq.possible[i] = p->interrupts[i];
 136                                 link->irq.possible_count++;
 137                         }
 138                         link->irq.triggering = p->triggering;
 139                         link->irq.polarity = p->polarity;
 140                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 141                         break;
 142                 }
 143         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 144                 {
 145                         struct acpi_resource_extended_irq *p =
 146                             &resource->data.extended_irq;
 147                         if (!p || !p->interrupt_count) {
 148                                 printk(KERN_WARNING PREFIX
 149                                               "Blank _PRS EXT IRQ resource\n");
 150                                 return AE_OK;
 151                         }
 152                         for (i = 0;
 153                              (i < p->interrupt_count
 154                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 155                                 if (!p->interrupts[i]) {
 156                                         printk(KERN_WARNING PREFIX
 157                                                "Invalid _PRS IRQ %d\n",
 158                                                p->interrupts[i]);
 159                                         continue;
 160                                 }
 161                                 link->irq.possible[i] = p->interrupts[i];
 162                                 link->irq.possible_count++;
 163                         }
 164                         link->irq.triggering = p->triggering;
 165                         link->irq.polarity = p->polarity;
 166                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 167                         break;
 168                 }
 169         default:
 170                 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 171                        resource->type);
 172                 return AE_OK;
 173         }
 174
 175         return AE_CTRL_TERMINATE;
 176 }
 177
 178 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 179 {
 180         acpi_status status;
 181
 182         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 183                                      acpi_pci_link_check_possible, link);
 184         if (ACPI_FAILURE(status)) {
 185                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 186                 return -ENODEV;
 187         }
 188
 189         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 190                           "Found %d possible IRQs\n",
 191                           link->irq.possible_count));
 192
 193         return 0;
 194 }
 195
 196 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 197                                                void *context)
 198 {
 199         int *irq = context;
 200
 201         switch (resource->type) {
 202         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 203         case ACPI_RESOURCE_TYPE_END_TAG:
 204                 return AE_OK;
 205         case ACPI_RESOURCE_TYPE_IRQ:
 206                 {
 207                         struct acpi_resource_irq *p = &resource->data.irq;
 208                         if (!p || !p->interrupt_count) {
 209                                 /*
 210                                  * IRQ descriptors may have no IRQ# bits set,
 211                                  * particularly those those w/ _STA disabled
 212                                  */
 213                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 214                                                   "Blank _CRS IRQ resource\n"));
 215                                 return AE_OK;
 216                         }
 217                         *irq = p->interrupts[0];
 218                         break;
 219                 }
 220         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 221                 {
 222                         struct acpi_resource_extended_irq *p =
 223                             &resource->data.extended_irq;
 224                         if (!p || !p->interrupt_count) {
 225                                 /*
 226                                  * extended IRQ descriptors must
 227                                  * return at least 1 IRQ
 228                                  */
 229                                 printk(KERN_WARNING PREFIX
 230                                               "Blank _CRS EXT IRQ resource\n");
 231                                 return AE_OK;
 232                         }
 233                         *irq = p->interrupts[0];
 234                         break;
 235                 }
 236                 break;
 237         default:
 238                 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 239                        resource->type);
 240                 return AE_OK;
 241         }
 242
 243         return AE_CTRL_TERMINATE;
 244 }
 245
 246 /*
 247  * Run _CRS and set link->irq.active
 248  *
 249  * return value:
 250  * 0 - success
 251  * !0 - failure
 252  */
 253 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 254 {
 255         int result = 0;
 256         acpi_status status;
 257         int irq = 0;
 258
 259         link->irq.active = 0;
 260
 261         /* in practice, status disabled is meaningless, ignore it */
 262         if (acpi_strict) {
 263                 /* Query _STA, set link->device->status */
 264                 result = acpi_bus_get_status(link->device);
 265                 if (result) {
 266                         printk(KERN_ERR PREFIX "Unable to read status\n");
 267                         goto end;
 268                 }
 269
 270                 if (!link->device->status.enabled) {
 271                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 272                         return 0;
 273                 }
 274         }
 275
 276         /*
 277          * Query and parse _CRS to get the current IRQ assignment.
 278          */
 279
 280         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 281                                      acpi_pci_link_check_current, &irq);
 282         if (ACPI_FAILURE(status)) {
 283                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 284                 result = -ENODEV;
 285                 goto end;
 286         }
 287
 288         if (acpi_strict && !irq) {
 289                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 290                 result = -ENODEV;
 291         }
 292
 293         link->irq.active = irq;
 294
 295         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 296
 297       end:
 298         return result;
 299 }
 300
 301 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 302 {
 303         int result;
 304         acpi_status status;
 305         struct {
 306                 struct acpi_resource res;
 307                 struct acpi_resource end;
 308         } *resource;
 309         struct acpi_buffer buffer = { 0, NULL };
 310
 311         if (!irq)
 312                 return -EINVAL;
 313
 314         resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 315         if (!resource)
 316                 return -ENOMEM;
 317
 318         buffer.length = sizeof(*resource) + 1;
 319         buffer.pointer = resource;
 320
 321         switch (link->irq.resource_type) {
 322         case ACPI_RESOURCE_TYPE_IRQ:
 323                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 324                 resource->res.length = sizeof(struct acpi_resource);
 325                 resource->res.data.irq.triggering = link->irq.triggering;
 326                 resource->res.data.irq.polarity =
 327                     link->irq.polarity;
 328                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 329                         resource->res.data.irq.sharable =
 330                             ACPI_EXCLUSIVE;
 331                 else
 332                         resource->res.data.irq.sharable = ACPI_SHARED;
 333                 resource->res.data.irq.interrupt_count = 1;
 334                 resource->res.data.irq.interrupts[0] = irq;
 335                 break;
 336
 337         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 338                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 339                 resource->res.length = sizeof(struct acpi_resource);
 340                 resource->res.data.extended_irq.producer_consumer =
 341                     ACPI_CONSUMER;
 342                 resource->res.data.extended_irq.triggering =
 343                     link->irq.triggering;
 344                 resource->res.data.extended_irq.polarity =
 345                     link->irq.polarity;
 346                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 347                         resource->res.data.irq.sharable =
 348                             ACPI_EXCLUSIVE;
 349                 else
 350                         resource->res.data.irq.sharable = ACPI_SHARED;
 351                 resource->res.data.extended_irq.interrupt_count = 1;
 352                 resource->res.data.extended_irq.interrupts[0] = irq;
 353                 /* ignore resource_source, it's optional */
 354                 break;
 355         default:
 356                 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 357                 result = -EINVAL;
 358                 goto end;
 359
 360         }
 361         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 362
 363         /* Attempt to set the resource */
 364         status = acpi_set_current_resources(link->device->handle, &buffer);
 365
 366         /* check for total failure */
 367         if (ACPI_FAILURE(status)) {
 368                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 369                 result = -ENODEV;
 370                 goto end;
 371         }
 372
 373         /* Query _STA, set device->status */
 374         result = acpi_bus_get_status(link->device);
 375         if (result) {
 376                 printk(KERN_ERR PREFIX "Unable to read status\n");
 377                 goto end;
 378         }
 379         if (!link->device->status.enabled) {
 380                 printk(KERN_WARNING PREFIX
 381                               "%s [%s] disabled and referenced, BIOS bug\n",
 382                               acpi_device_name(link->device),
 383                               acpi_device_bid(link->device));
 384         }
 385
 386         /* Query _CRS, set link->irq.active */
 387         result = acpi_pci_link_get_current(link);
 388         if (result) {
 389                 goto end;
 390         }
 391
 392         /*
 393          * Is current setting not what we set?
 394          * set link->irq.active
 395          */
 396         if (link->irq.active != irq) {
 397                 /*
 398                  * policy: when _CRS doesn't return what we just _SRS
 399                  * assume _SRS worked and override _CRS value.
 400                  */
 401                 printk(KERN_WARNING PREFIX
 402                               "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 403                               acpi_device_name(link->device),
 404                               acpi_device_bid(link->device), link->irq.active, irq);
 405                 link->irq.active = irq;
 406         }
 407
 408         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 409
 410       end:
 411         kfree(resource);
 412         return result;
 413 }
 414
 415 /* --------------------------------------------------------------------------
 416                             PCI Link IRQ Management
 417    -------------------------------------------------------------------------- */
 418
 419 /*
 420  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 421  * Link Devices to move the PIRQs around to minimize sharing.
 422  *
 423  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 424  * that the BIOS has already set to active.  This is necessary because
 425  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 426  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 427  * even if acpi_irq_nobalance is set.
 428  *
 429  * A tables of penalties avoids directing PCI interrupts to well known
 430  * ISA IRQs. Boot params are available to over-ride the default table:
 431  *
 432  * List interrupts that are free for PCI use.
 433  * acpi_irq_pci=n[,m]
 434  *
 435  * List interrupts that should not be used for PCI:
 436  * acpi_irq_isa=n[,m]
 437  *
 438  * Note that PCI IRQ routers have a list of possible IRQs,
 439  * which may not include the IRQs this table says are available.
 440  *
 441  * Since this heuristic can't tell the difference between a link
 442  * that no device will attach to, vs. a link which may be shared
 443  * by multiple active devices -- it is not optimal.
 444  *
 445  * If interrupt performance is that important, get an IO-APIC system
 446  * with a pin dedicated to each device.  Or for that matter, an MSI
 447  * enabled system.
 448  */
 449
 450 #define ACPI_MAX_IRQS           256
 451 #define ACPI_MAX_ISA_IRQ        16
 452
 453 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 454 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 455 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 456 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 457 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 458 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 459
 460 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 461         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 462         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 463         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 464         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 465         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 466         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 467         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 468         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 469         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 470         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 471         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 472         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 473         PIRQ_PENALTY_ISA_USED,          /* IRQ12 mouse */
 474         PIRQ_PENALTY_ISA_USED,          /* IRQ13 fpe, sometimes */
 475         PIRQ_PENALTY_ISA_USED,          /* IRQ14 ide0 */
 476         PIRQ_PENALTY_ISA_USED,          /* IRQ15 ide1 */
 477         /* >IRQ15 */
 478 };
 479
 480 int __init acpi_irq_penalty_init(void)
 481 {
 482         struct acpi_pci_link *link;
 483         int i;
 484
 485         /*
 486          * Update penalties to facilitate IRQ balancing.
 487          */
 488         list_for_each_entry(link, &acpi_link_list, list) {
 489
 490                 /*
 491                  * reflect the possible and active irqs in the penalty table --
 492                  * useful for breaking ties.
 493                  */
 494                 if (link->irq.possible_count) {
 495                         int penalty =
 496                             PIRQ_PENALTY_PCI_POSSIBLE /
 497                             link->irq.possible_count;
 498
 499                         for (i = 0; i < link->irq.possible_count; i++) {
 500                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 501                                         acpi_irq_penalty[link->irq.
 502                                                          possible[i]] +=
 503                                             penalty;
 504                         }
 505
 506                 } else if (link->irq.active) {
 507                         acpi_irq_penalty[link->irq.active] +=
 508                             PIRQ_PENALTY_PCI_POSSIBLE;
 509                 }
 510         }
 511         /* Add a penalty for the SCI */
 512         acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
 513         return 0;
 514 }
 515
 516 static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 517
 518 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 519 {
 520         int irq;
 521         int i;
 522
 523         if (link->irq.initialized) {
 524                 if (link->refcnt == 0)
 525                         /* This means the link is disabled but initialized */
 526                         acpi_pci_link_set(link, link->irq.active);
 527                 return 0;
 528         }
 529
 530         /*
 531          * search for active IRQ in list of possible IRQs.
 532          */
 533         for (i = 0; i < link->irq.possible_count; ++i) {
 534                 if (link->irq.active == link->irq.possible[i])
 535                         break;
 536         }
 537         /*
 538          * forget active IRQ that is not in possible list
 539          */
 540         if (i == link->irq.possible_count) {
 541                 if (acpi_strict)
 542                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 543                                       " in _PRS\n", link->irq.active);
 544                 link->irq.active = 0;
 545         }
 546
 547         /*
 548          * if active found, use it; else pick entry from end of possible list.
 549          */
 550         if (link->irq.active)
 551                 irq = link->irq.active;
 552         else
 553                 irq = link->irq.possible[link->irq.possible_count - 1];
 554
 555         if (acpi_irq_balance || !link->irq.active) {
 556                 /*
 557                  * Select the best IRQ.  This is done in reverse to promote
 558                  * the use of IRQs 9, 10, 11, and >15.
 559                  */
 560                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 561                         if (acpi_irq_penalty[irq] >
 562                             acpi_irq_penalty[link->irq.possible[i]])
 563                                 irq = link->irq.possible[i];
 564                 }
 565         }
 566
 567         /* Attempt to enable the link device at this IRQ. */
 568         if (acpi_pci_link_set(link, irq)) {
 569                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 570                             "Try pci=noacpi or acpi=off\n",
 571                             acpi_device_name(link->device),
 572                             acpi_device_bid(link->device));
 573                 return -ENODEV;
 574         } else {
 575                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 576                 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
 577                        acpi_device_name(link->device),
 578                        acpi_device_bid(link->device), link->irq.active);
 579         }
 580
 581         link->irq.initialized = 1;
 582         return 0;
 583 }
 584
 585 /*
 586  * acpi_pci_link_allocate_irq
 587  * success: return IRQ >= 0
 588  * failure: return -1
 589  */
 590 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 591                                int *polarity, char **name)
 592 {
 593         int result;
 594         struct acpi_device *device;
 595         struct acpi_pci_link *link;
 596
 597         result = acpi_bus_get_device(handle, &device);
 598         if (result) {
 599                 printk(KERN_ERR PREFIX "Invalid link device\n");
 600                 return -1;
 601         }
 602
 603         link = acpi_driver_data(device);
 604         if (!link) {
 605                 printk(KERN_ERR PREFIX "Invalid link context\n");
 606                 return -1;
 607         }
 608
 609         /* TBD: Support multiple index (IRQ) entries per Link Device */
 610         if (index) {
 611                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 612                 return -1;
 613         }
 614
 615         mutex_lock(&acpi_link_lock);
 616         if (acpi_pci_link_allocate(link)) {
 617                 mutex_unlock(&acpi_link_lock);
 618                 return -1;
 619         }
 620
 621         if (!link->irq.active) {
 622                 mutex_unlock(&acpi_link_lock);
 623                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 624                 return -1;
 625         }
 626         link->refcnt++;
 627         mutex_unlock(&acpi_link_lock);
 628
 629         if (triggering)
 630                 *triggering = link->irq.triggering;
 631         if (polarity)
 632                 *polarity = link->irq.polarity;
 633         if (name)
 634                 *name = acpi_device_bid(link->device);
 635         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 636                           "Link %s is referenced\n",
 637                           acpi_device_bid(link->device)));
 638         return (link->irq.active);
 639 }
 640
 641 /*
 642  * We don't change link's irq information here.  After it is reenabled, we
 643  * continue use the info
 644  */
 645 int acpi_pci_link_free_irq(acpi_handle handle)
 646 {
 647         struct acpi_device *device;
 648         struct acpi_pci_link *link;
 649         acpi_status result;
 650
 651         result = acpi_bus_get_device(handle, &device);
 652         if (result) {
 653                 printk(KERN_ERR PREFIX "Invalid link device\n");
 654                 return -1;
 655         }
 656
 657         link = acpi_driver_data(device);
 658         if (!link) {
 659                 printk(KERN_ERR PREFIX "Invalid link context\n");
 660                 return -1;
 661         }
 662
 663         mutex_lock(&acpi_link_lock);
 664         if (!link->irq.initialized) {
 665                 mutex_unlock(&acpi_link_lock);
 666                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 667                 return -1;
 668         }
 669 #ifdef  FUTURE_USE
 670         /*
 671          * The Link reference count allows us to _DISable an unused link
 672          * and suspend time, and set it again  on resume.
 673          * However, 2.6.12 still has irq_router.resume
 674          * which blindly restores the link state.
 675          * So we disable the reference count method
 676          * to prevent duplicate acpi_pci_link_set()
 677          * which would harm some systems
 678          */
 679         link->refcnt--;
 680 #endif
 681         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 682                           "Link %s is dereferenced\n",
 683                           acpi_device_bid(link->device)));
 684
 685         if (link->refcnt == 0)
 686                 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 687
 688         mutex_unlock(&acpi_link_lock);
 689         return (link->irq.active);
 690 }
 691
 692 /* --------------------------------------------------------------------------
 693                                  Driver Interface
 694    -------------------------------------------------------------------------- */
 695
 696 static int acpi_pci_link_add(struct acpi_device *device)
 697 {
 698         int result;
 699         struct acpi_pci_link *link;
 700         int i;
 701         int found = 0;
 702
 703         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 704         if (!link)
 705                 return -ENOMEM;
 706
 707         link->device = device;
 708         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 709         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 710         device->driver_data = link;
 711
 712         mutex_lock(&acpi_link_lock);
 713         result = acpi_pci_link_get_possible(link);
 714         if (result)
 715                 goto end;
 716
 717         /* query and set link->irq.active */
 718         acpi_pci_link_get_current(link);
 719
 720         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 721                acpi_device_bid(device));
 722         for (i = 0; i < link->irq.possible_count; i++) {
 723                 if (link->irq.active == link->irq.possible[i]) {
 724                         printk(" *%d", link->irq.possible[i]);
 725                         found = 1;
 726                 } else
 727                         printk(" %d", link->irq.possible[i]);
 728         }
 729
 730         printk(")");
 731
 732         if (!found)
 733                 printk(" *%d", link->irq.active);
 734
 735         if (!link->device->status.enabled)
 736                 printk(", disabled.");
 737
 738         printk("\n");
 739
 740         list_add_tail(&link->list, &acpi_link_list);
 741
 742       end:
 743         /* disable all links -- to be activated on use */
 744         acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 745         mutex_unlock(&acpi_link_lock);
 746
 747         if (result)
 748                 kfree(link);
 749
 750         return result;
 751 }
 752
 753 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 754 {
 755         if (link->refcnt && link->irq.active && link->irq.initialized)
 756                 return (acpi_pci_link_set(link, link->irq.active));
 757
 758         return 0;
 759 }
 760
 761 static int irqrouter_resume(struct sys_device *dev)
 762 {
 763         struct acpi_pci_link *link;
 764
 765         list_for_each_entry(link, &acpi_link_list, list) {
 766                 acpi_pci_link_resume(link);
 767         }
 768         return 0;
 769 }
 770
 771 static int acpi_pci_link_remove(struct acpi_device *device, int type)
 772 {
 773         struct acpi_pci_link *link;
 774
 775         link = acpi_driver_data(device);
 776
 777         mutex_lock(&acpi_link_lock);
 778         list_del(&link->list);
 779         mutex_unlock(&acpi_link_lock);
 780
 781         kfree(link);
 782         return 0;
 783 }
 784
 785 /*
 786  * modify acpi_irq_penalty[] from cmdline
 787  */
 788 static int __init acpi_irq_penalty_update(char *str, int used)
 789 {
 790         int i;
 791
 792         for (i = 0; i < 16; i++) {
 793                 int retval;
 794                 int irq;
 795
 796                 retval = get_option(&str, &irq);
 797
 798                 if (!retval)
 799                         break;  /* no number found */
 800
 801                 if (irq < 0)
 802                         continue;
 803
 804                 if (irq >= ARRAY_SIZE(acpi_irq_penalty))
 805                         continue;
 806
 807                 if (used)
 808                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 809                 else
 810                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 811
 812                 if (retval != 2)        /* no next number */
 813                         break;
 814         }
 815         return 1;
 816 }
 817
 818 /*
 819  * We'd like PNP to call this routine for the
 820  * single ISA_USED value for each legacy device.
 821  * But instead it calls us with each POSSIBLE setting.
 822  * There is no ISA_POSSIBLE weight, so we simply use
 823  * the (small) PCI_USING penalty.
 824  */
 825 void acpi_penalize_isa_irq(int irq, int active)
 826 {
 827         if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 828                 if (active)
 829                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 830                 else
 831                         acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 832         }
 833 }
 834
 835 /*
 836  * Over-ride default table to reserve additional IRQs for use by ISA
 837  * e.g. acpi_irq_isa=5
 838  * Useful for telling ACPI how not to interfere with your ISA sound card.
 839  */
 840 static int __init acpi_irq_isa(char *str)
 841 {
 842         return acpi_irq_penalty_update(str, 1);
 843 }
 844
 845 __setup("acpi_irq_isa=", acpi_irq_isa);
 846
 847 /*
 848  * Over-ride default table to free additional IRQs for use by PCI
 849  * e.g. acpi_irq_pci=7,15
 850  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 851  */
 852 static int __init acpi_irq_pci(char *str)
 853 {
 854         return acpi_irq_penalty_update(str, 0);
 855 }
 856
 857 __setup("acpi_irq_pci=", acpi_irq_pci);
 858
 859 static int __init acpi_irq_nobalance_set(char *str)
 860 {
 861         acpi_irq_balance = 0;
 862         return 1;
 863 }
 864
 865 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 866
 867 static int __init acpi_irq_balance_set(char *str)
 868 {
 869         acpi_irq_balance = 1;
 870         return 1;
 871 }
 872
 873 __setup("acpi_irq_balance", acpi_irq_balance_set);
 874
 875 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 876 static struct sysdev_class irqrouter_sysdev_class = {
 877         .name = "irqrouter",
 878         .resume = irqrouter_resume,
 879 };
 880
 881 static struct sys_device device_irqrouter = {
 882         .id = 0,
 883         .cls = &irqrouter_sysdev_class,
 884 };
 885
 886 static int __init irqrouter_init_sysfs(void)
 887 {
 888         int error;
 889
 890         if (acpi_disabled || acpi_noirq)
 891                 return 0;
 892
 893         error = sysdev_class_register(&irqrouter_sysdev_class);
 894         if (!error)
 895                 error = sysdev_register(&device_irqrouter);
 896
 897         return error;
 898 }
 899
 900 device_initcall(irqrouter_init_sysfs);
 901
 902 static int __init acpi_pci_link_init(void)
 903 {
 904         if (acpi_noirq)
 905                 return 0;
 906
 907         if (acpi_irq_balance == -1) {
 908                 /* no command line switch: enable balancing in IOAPIC mode */
 909                 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 910                         acpi_irq_balance = 1;
 911                 else
 912                         acpi_irq_balance = 0;
 913         }
 914
 915         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 916                 return -ENODEV;
 917
 918         return 0;
 919 }
 920
 921 subsys_initcall(acpi_pci_link_init);