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
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45
  46 #define _COMPONENT              ACPI_PCI_COMPONENT
  47 ACPI_MODULE_NAME("pci_link");
  48 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  49 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  50 #define ACPI_PCI_LINK_FILE_INFO         "info"
  51 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  52 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  53 static int acpi_pci_link_add(struct acpi_device *device);
  54 static int acpi_pci_link_remove(struct acpi_device *device, int type);
  55
  56 static struct acpi_device_id link_device_ids[] = {
  57         {"PNP0C0F", 0},
  58         {"", 0},
  59 };
  60 MODULE_DEVICE_TABLE(acpi, link_device_ids);
  61
  62 static struct acpi_driver acpi_pci_link_driver = {
  63         .name = "pci_link",
  64         .class = ACPI_PCI_LINK_CLASS,
  65         .ids = link_device_ids,
  66         .ops = {
  67                 .add = acpi_pci_link_add,
  68                 .remove = acpi_pci_link_remove,
  69                 },
  70 };
  71
  72 /*
  73  * If a link is initialized, we never change its active and initialized
  74  * later even the link is disable. Instead, we just repick the active irq
  75  */
  76 struct acpi_pci_link_irq {
  77         u8 active;              /* Current IRQ */
  78         u8 triggering;          /* All IRQs */
  79         u8 polarity;    /* All IRQs */
  80         u8 resource_type;
  81         u8 possible_count;
  82         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  83         u8 initialized:1;
  84         u8 reserved:7;
  85 };
  86
  87 struct acpi_pci_link {
  88         struct list_head node;
  89         struct acpi_device *device;
  90         struct acpi_pci_link_irq irq;
  91         int refcnt;
  92 };
  93
  94 static struct {
  95         int count;
  96         struct list_head entries;
  97 } acpi_link;
  98 DEFINE_MUTEX(acpi_link_lock);
  99
 100 /* --------------------------------------------------------------------------
 101                             PCI Link Device Management
 102    -------------------------------------------------------------------------- */
 103
 104 /*
 105  * set context (link) possible list from resource list
 106  */
 107 static acpi_status
 108 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
 109 {
 110         struct acpi_pci_link *link = context;
 111         u32 i = 0;
 112
 113
 114         switch (resource->type) {
 115         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 116                 return AE_OK;
 117         case ACPI_RESOURCE_TYPE_IRQ:
 118                 {
 119                         struct acpi_resource_irq *p = &resource->data.irq;
 120                         if (!p || !p->interrupt_count) {
 121                                 printk(KERN_WARNING PREFIX "Blank IRQ resource\n");
 122                                 return AE_OK;
 123                         }
 124                         for (i = 0;
 125                              (i < p->interrupt_count
 126                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 127                                 if (!p->interrupts[i]) {
 128                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
 129                                                       p->interrupts[i]);
 130                                         continue;
 131                                 }
 132                                 link->irq.possible[i] = p->interrupts[i];
 133                                 link->irq.possible_count++;
 134                         }
 135                         link->irq.triggering = p->triggering;
 136                         link->irq.polarity = p->polarity;
 137                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 138                         break;
 139                 }
 140         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 141                 {
 142                         struct acpi_resource_extended_irq *p =
 143                             &resource->data.extended_irq;
 144                         if (!p || !p->interrupt_count) {
 145                                 printk(KERN_WARNING PREFIX
 146                                               "Blank EXT IRQ resource\n");
 147                                 return AE_OK;
 148                         }
 149                         for (i = 0;
 150                              (i < p->interrupt_count
 151                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 152                                 if (!p->interrupts[i]) {
 153                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
 154                                                       p->interrupts[i]);
 155                                         continue;
 156                                 }
 157                                 link->irq.possible[i] = p->interrupts[i];
 158                                 link->irq.possible_count++;
 159                         }
 160                         link->irq.triggering = p->triggering;
 161                         link->irq.polarity = p->polarity;
 162                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 163                         break;
 164                 }
 165         default:
 166                 printk(KERN_ERR PREFIX "Resource is not an IRQ entry\n");
 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
 178         if (!link)
 179                 return -EINVAL;
 180
 181         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 182                                      acpi_pci_link_check_possible, link);
 183         if (ACPI_FAILURE(status)) {
 184                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 185                 return -ENODEV;
 186         }
 187
 188         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 189                           "Found %d possible IRQs\n",
 190                           link->irq.possible_count));
 191
 192         return 0;
 193 }
 194
 195 static acpi_status
 196 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
 197 {
 198         int *irq = (int *)context;
 199
 200
 201         switch (resource->type) {
 202         case ACPI_RESOURCE_TYPE_IRQ:
 203                 {
 204                         struct acpi_resource_irq *p = &resource->data.irq;
 205                         if (!p || !p->interrupt_count) {
 206                                 /*
 207                                  * IRQ descriptors may have no IRQ# bits set,
 208                                  * particularly those those w/ _STA disabled
 209                                  */
 210                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 211                                                   "Blank IRQ resource\n"));
 212                                 return AE_OK;
 213                         }
 214                         *irq = p->interrupts[0];
 215                         break;
 216                 }
 217         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 218                 {
 219                         struct acpi_resource_extended_irq *p =
 220                             &resource->data.extended_irq;
 221                         if (!p || !p->interrupt_count) {
 222                                 /*
 223                                  * extended IRQ descriptors must
 224                                  * return at least 1 IRQ
 225                                  */
 226                                 printk(KERN_WARNING PREFIX
 227                                               "Blank EXT IRQ resource\n");
 228                                 return AE_OK;
 229                         }
 230                         *irq = p->interrupts[0];
 231                         break;
 232                 }
 233                 break;
 234         default:
 235                 printk(KERN_ERR PREFIX "Resource %d isn't an IRQ\n", resource->type);
 236         case ACPI_RESOURCE_TYPE_END_TAG:
 237                 return AE_OK;
 238         }
 239         return AE_CTRL_TERMINATE;
 240 }
 241
 242 /*
 243  * Run _CRS and set link->irq.active
 244  *
 245  * return value:
 246  * 0 - success
 247  * !0 - failure
 248  */
 249 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 250 {
 251         int result = 0;
 252         acpi_status status = AE_OK;
 253         int irq = 0;
 254
 255         if (!link)
 256                 return -EINVAL;
 257
 258         link->irq.active = 0;
 259
 260         /* in practice, status disabled is meaningless, ignore it */
 261         if (acpi_strict) {
 262                 /* Query _STA, set link->device->status */
 263                 result = acpi_bus_get_status(link->device);
 264                 if (result) {
 265                         printk(KERN_ERR PREFIX "Unable to read status\n");
 266                         goto end;
 267                 }
 268
 269                 if (!link->device->status.enabled) {
 270                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 271                         return 0;
 272                 }
 273         }
 274
 275         /*
 276          * Query and parse _CRS to get the current IRQ assignment.
 277          */
 278
 279         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 280                                      acpi_pci_link_check_current, &irq);
 281         if (ACPI_FAILURE(status)) {
 282                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 283                 result = -ENODEV;
 284                 goto end;
 285         }
 286
 287         if (acpi_strict && !irq) {
 288                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 289                 result = -ENODEV;
 290         }
 291
 292         link->irq.active = irq;
 293
 294         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 295
 296       end:
 297         return result;
 298 }
 299
 300 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 301 {
 302         int result = 0;
 303         acpi_status status = AE_OK;
 304         struct {
 305                 struct acpi_resource res;
 306                 struct acpi_resource end;
 307         } *resource;
 308         struct acpi_buffer buffer = { 0, NULL };
 309
 310
 311         if (!link || !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 list_head *node = NULL;
 483         struct acpi_pci_link *link = NULL;
 484         int i = 0;
 485
 486
 487         /*
 488          * Update penalties to facilitate IRQ balancing.
 489          */
 490         list_for_each(node, &acpi_link.entries) {
 491
 492                 link = list_entry(node, struct acpi_pci_link, node);
 493                 if (!link) {
 494                         printk(KERN_ERR PREFIX "Invalid link context\n");
 495                         continue;
 496                 }
 497
 498                 /*
 499                  * reflect the possible and active irqs in the penalty table --
 500                  * useful for breaking ties.
 501                  */
 502                 if (link->irq.possible_count) {
 503                         int penalty =
 504                             PIRQ_PENALTY_PCI_POSSIBLE /
 505                             link->irq.possible_count;
 506
 507                         for (i = 0; i < link->irq.possible_count; i++) {
 508                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 509                                         acpi_irq_penalty[link->irq.
 510                                                          possible[i]] +=
 511                                             penalty;
 512                         }
 513
 514                 } else if (link->irq.active) {
 515                         acpi_irq_penalty[link->irq.active] +=
 516                             PIRQ_PENALTY_PCI_POSSIBLE;
 517                 }
 518         }
 519         /* Add a penalty for the SCI */
 520         acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
 521
 522         return 0;
 523 }
 524
 525 static int acpi_irq_balance;    /* 0: static, 1: balance */
 526
 527 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 528 {
 529         int irq;
 530         int i;
 531
 532
 533         if (link->irq.initialized) {
 534                 if (link->refcnt == 0)
 535                         /* This means the link is disabled but initialized */
 536                         acpi_pci_link_set(link, link->irq.active);
 537                 return 0;
 538         }
 539
 540         /*
 541          * search for active IRQ in list of possible IRQs.
 542          */
 543         for (i = 0; i < link->irq.possible_count; ++i) {
 544                 if (link->irq.active == link->irq.possible[i])
 545                         break;
 546         }
 547         /*
 548          * forget active IRQ that is not in possible list
 549          */
 550         if (i == link->irq.possible_count) {
 551                 if (acpi_strict)
 552                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 553                                       " in _PRS\n", link->irq.active);
 554                 link->irq.active = 0;
 555         }
 556
 557         /*
 558          * if active found, use it; else pick entry from end of possible list.
 559          */
 560         if (link->irq.active) {
 561                 irq = link->irq.active;
 562         } else {
 563                 irq = link->irq.possible[link->irq.possible_count - 1];
 564         }
 565
 566         if (acpi_irq_balance || !link->irq.active) {
 567                 /*
 568                  * Select the best IRQ.  This is done in reverse to promote
 569                  * the use of IRQs 9, 10, 11, and >15.
 570                  */
 571                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 572                         if (acpi_irq_penalty[irq] >
 573                             acpi_irq_penalty[link->irq.possible[i]])
 574                                 irq = link->irq.possible[i];
 575                 }
 576         }
 577
 578         /* Attempt to enable the link device at this IRQ. */
 579         if (acpi_pci_link_set(link, irq)) {
 580                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 581                             "Try pci=noacpi or acpi=off\n",
 582                             acpi_device_name(link->device),
 583                             acpi_device_bid(link->device));
 584                 return -ENODEV;
 585         } else {
 586                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 587                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 588                        acpi_device_name(link->device),
 589                        acpi_device_bid(link->device), link->irq.active);
 590         }
 591
 592         link->irq.initialized = 1;
 593
 594         return 0;
 595 }
 596
 597 /*
 598  * acpi_pci_link_allocate_irq
 599  * success: return IRQ >= 0
 600  * failure: return -1
 601  */
 602
 603 int
 604 acpi_pci_link_allocate_irq(acpi_handle handle,
 605                            int index,
 606                            int *triggering, int *polarity, char **name)
 607 {
 608         int result = 0;
 609         struct acpi_device *device = NULL;
 610         struct acpi_pci_link *link = NULL;
 611
 612
 613         result = acpi_bus_get_device(handle, &device);
 614         if (result) {
 615                 printk(KERN_ERR PREFIX "Invalid link device\n");
 616                 return -1;
 617         }
 618
 619         link = acpi_driver_data(device);
 620         if (!link) {
 621                 printk(KERN_ERR PREFIX "Invalid link context\n");
 622                 return -1;
 623         }
 624
 625         /* TBD: Support multiple index (IRQ) entries per Link Device */
 626         if (index) {
 627                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 628                 return -1;
 629         }
 630
 631         mutex_lock(&acpi_link_lock);
 632         if (acpi_pci_link_allocate(link)) {
 633                 mutex_unlock(&acpi_link_lock);
 634                 return -1;
 635         }
 636
 637         if (!link->irq.active) {
 638                 mutex_unlock(&acpi_link_lock);
 639                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 640                 return -1;
 641         }
 642         link->refcnt++;
 643         mutex_unlock(&acpi_link_lock);
 644
 645         if (triggering)
 646                 *triggering = link->irq.triggering;
 647         if (polarity)
 648                 *polarity = link->irq.polarity;
 649         if (name)
 650                 *name = acpi_device_bid(link->device);
 651         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 652                           "Link %s is referenced\n",
 653                           acpi_device_bid(link->device)));
 654         return (link->irq.active);
 655 }
 656
 657 /*
 658  * We don't change link's irq information here.  After it is reenabled, we
 659  * continue use the info
 660  */
 661 int acpi_pci_link_free_irq(acpi_handle handle)
 662 {
 663         struct acpi_device *device = NULL;
 664         struct acpi_pci_link *link = NULL;
 665         acpi_status result;
 666
 667
 668         result = acpi_bus_get_device(handle, &device);
 669         if (result) {
 670                 printk(KERN_ERR PREFIX "Invalid link device\n");
 671                 return -1;
 672         }
 673
 674         link = acpi_driver_data(device);
 675         if (!link) {
 676                 printk(KERN_ERR PREFIX "Invalid link context\n");
 677                 return -1;
 678         }
 679
 680         mutex_lock(&acpi_link_lock);
 681         if (!link->irq.initialized) {
 682                 mutex_unlock(&acpi_link_lock);
 683                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 684                 return -1;
 685         }
 686 #ifdef  FUTURE_USE
 687         /*
 688          * The Link reference count allows us to _DISable an unused link
 689          * and suspend time, and set it again  on resume.
 690          * However, 2.6.12 still has irq_router.resume
 691          * which blindly restores the link state.
 692          * So we disable the reference count method
 693          * to prevent duplicate acpi_pci_link_set()
 694          * which would harm some systems
 695          */
 696         link->refcnt--;
 697 #endif
 698         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 699                           "Link %s is dereferenced\n",
 700                           acpi_device_bid(link->device)));
 701
 702         if (link->refcnt == 0) {
 703                 acpi_ut_evaluate_object(link->device->handle, "_DIS", 0, NULL);
 704         }
 705         mutex_unlock(&acpi_link_lock);
 706         return (link->irq.active);
 707 }
 708
 709 /* --------------------------------------------------------------------------
 710                                  Driver Interface
 711    -------------------------------------------------------------------------- */
 712
 713 static int acpi_pci_link_add(struct acpi_device *device)
 714 {
 715         int result = 0;
 716         struct acpi_pci_link *link = NULL;
 717         int i = 0;
 718         int found = 0;
 719
 720
 721         if (!device)
 722                 return -EINVAL;
 723
 724         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 725         if (!link)
 726                 return -ENOMEM;
 727
 728         link->device = device;
 729         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 730         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 731         acpi_driver_data(device) = link;
 732
 733         mutex_lock(&acpi_link_lock);
 734         result = acpi_pci_link_get_possible(link);
 735         if (result)
 736                 goto end;
 737
 738         /* query and set link->irq.active */
 739         acpi_pci_link_get_current(link);
 740
 741         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 742                acpi_device_bid(device));
 743         for (i = 0; i < link->irq.possible_count; i++) {
 744                 if (link->irq.active == link->irq.possible[i]) {
 745                         printk(" *%d", link->irq.possible[i]);
 746                         found = 1;
 747                 } else
 748                         printk(" %d", link->irq.possible[i]);
 749         }
 750
 751         printk(")");
 752
 753         if (!found)
 754                 printk(" *%d", link->irq.active);
 755
 756         if (!link->device->status.enabled)
 757                 printk(", disabled.");
 758
 759         printk("\n");
 760
 761         /* TBD: Acquire/release lock */
 762         list_add_tail(&link->node, &acpi_link.entries);
 763         acpi_link.count++;
 764
 765       end:
 766         /* disable all links -- to be activated on use */
 767         acpi_ut_evaluate_object(device->handle, "_DIS", 0, NULL);
 768         mutex_unlock(&acpi_link_lock);
 769
 770         if (result)
 771                 kfree(link);
 772
 773         return result;
 774 }
 775
 776 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 777 {
 778
 779         if (link->refcnt && link->irq.active && link->irq.initialized)
 780                 return (acpi_pci_link_set(link, link->irq.active));
 781         else
 782                 return 0;
 783 }
 784
 785 static int irqrouter_resume(struct sys_device *dev)
 786 {
 787         struct list_head *node = NULL;
 788         struct acpi_pci_link *link = NULL;
 789
 790
 791         /* Make sure SCI is enabled again (Apple firmware bug?) */
 792         acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
 793
 794         list_for_each(node, &acpi_link.entries) {
 795                 link = list_entry(node, struct acpi_pci_link, node);
 796                 if (!link) {
 797                         printk(KERN_ERR PREFIX "Invalid link context\n");
 798                         continue;
 799                 }
 800                 acpi_pci_link_resume(link);
 801         }
 802         return 0;
 803 }
 804
 805 static int acpi_pci_link_remove(struct acpi_device *device, int type)
 806 {
 807         struct acpi_pci_link *link = NULL;
 808
 809
 810         if (!device || !acpi_driver_data(device))
 811                 return -EINVAL;
 812
 813         link = acpi_driver_data(device);
 814
 815         mutex_lock(&acpi_link_lock);
 816         list_del(&link->node);
 817         mutex_unlock(&acpi_link_lock);
 818
 819         kfree(link);
 820
 821         return 0;
 822 }
 823
 824 /*
 825  * modify acpi_irq_penalty[] from cmdline
 826  */
 827 static int __init acpi_irq_penalty_update(char *str, int used)
 828 {
 829         int i;
 830
 831         for (i = 0; i < 16; i++) {
 832                 int retval;
 833                 int irq;
 834
 835                 retval = get_option(&str, &irq);
 836
 837                 if (!retval)
 838                         break;  /* no number found */
 839
 840                 if (irq < 0)
 841                         continue;
 842
 843                 if (irq >= ACPI_MAX_IRQS)
 844                         continue;
 845
 846                 if (used)
 847                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 848                 else
 849                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 850
 851                 if (retval != 2)        /* no next number */
 852                         break;
 853         }
 854         return 1;
 855 }
 856
 857 /*
 858  * We'd like PNP to call this routine for the
 859  * single ISA_USED value for each legacy device.
 860  * But instead it calls us with each POSSIBLE setting.
 861  * There is no ISA_POSSIBLE weight, so we simply use
 862  * the (small) PCI_USING penalty.
 863  */
 864 void acpi_penalize_isa_irq(int irq, int active)
 865 {
 866         if (active)
 867                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 868         else
 869                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 870 }
 871
 872 /*
 873  * Over-ride default table to reserve additional IRQs for use by ISA
 874  * e.g. acpi_irq_isa=5
 875  * Useful for telling ACPI how not to interfere with your ISA sound card.
 876  */
 877 static int __init acpi_irq_isa(char *str)
 878 {
 879         return acpi_irq_penalty_update(str, 1);
 880 }
 881
 882 __setup("acpi_irq_isa=", acpi_irq_isa);
 883
 884 /*
 885  * Over-ride default table to free additional IRQs for use by PCI
 886  * e.g. acpi_irq_pci=7,15
 887  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 888  */
 889 static int __init acpi_irq_pci(char *str)
 890 {
 891         return acpi_irq_penalty_update(str, 0);
 892 }
 893
 894 __setup("acpi_irq_pci=", acpi_irq_pci);
 895
 896 static int __init acpi_irq_nobalance_set(char *str)
 897 {
 898         acpi_irq_balance = 0;
 899         return 1;
 900 }
 901
 902 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 903
 904 int __init acpi_irq_balance_set(char *str)
 905 {
 906         acpi_irq_balance = 1;
 907         return 1;
 908 }
 909
 910 __setup("acpi_irq_balance", acpi_irq_balance_set);
 911
 912 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 913 static struct sysdev_class irqrouter_sysdev_class = {
 914         .name = "irqrouter",
 915         .resume = irqrouter_resume,
 916 };
 917
 918 static struct sys_device device_irqrouter = {
 919         .id = 0,
 920         .cls = &irqrouter_sysdev_class,
 921 };
 922
 923 static int __init irqrouter_init_sysfs(void)
 924 {
 925         int error;
 926
 927
 928         if (acpi_disabled || acpi_noirq)
 929                 return 0;
 930
 931         error = sysdev_class_register(&irqrouter_sysdev_class);
 932         if (!error)
 933                 error = sysdev_register(&device_irqrouter);
 934
 935         return error;
 936 }
 937
 938 device_initcall(irqrouter_init_sysfs);
 939
 940 static int __init acpi_pci_link_init(void)
 941 {
 942
 943         if (acpi_noirq)
 944                 return 0;
 945
 946         acpi_link.count = 0;
 947         INIT_LIST_HEAD(&acpi_link.entries);
 948
 949         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 950                 return -ENODEV;
 951
 952         return 0;
 953 }
 954
 955 subsys_initcall(acpi_pci_link_init);