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