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