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_HID               "PNP0C0F"
  50 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  51 #define ACPI_PCI_LINK_FILE_INFO         "info"
  52 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  53 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  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_driver acpi_pci_link_driver = {
  58         .name = "pci_link",
  59         .class = ACPI_PCI_LINK_CLASS,
  60         .ids = ACPI_PCI_LINK_HID,
  61         .ops = {
  62                 .add = acpi_pci_link_add,
  63                 .remove = acpi_pci_link_remove,
  64                 },
  65 };
  66
  67 /*
  68  * If a link is initialized, we never change its active and initialized
  69  * later even the link is disable. Instead, we just repick the active irq
  70  */
  71 struct acpi_pci_link_irq {
  72         u8 active;              /* Current IRQ */
  73         u8 triggering;          /* All IRQs */
  74         u8 polarity;    /* All IRQs */
  75         u8 resource_type;
  76         u8 possible_count;
  77         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  78         u8 initialized:1;
  79         u8 reserved:7;
  80 };
  81
  82 struct acpi_pci_link {
  83         struct list_head node;
  84         struct acpi_device *device;
  85         struct acpi_pci_link_irq irq;
  86         int refcnt;
  87 };
  88
  89 static struct {
  90         int count;
  91         struct list_head entries;
  92 } acpi_link;
  93 DEFINE_MUTEX(acpi_link_lock);
  94
  95 /* --------------------------------------------------------------------------
  96                             PCI Link Device Management
  97    -------------------------------------------------------------------------- */
  98
  99 /*
 100  * set context (link) possible list from resource list
 101  */
 102 static acpi_status
 103 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
 104 {
 105         struct acpi_pci_link *link = context;
 106         u32 i = 0;
 107
 108
 109         switch (resource->type) {
 110         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 111                 return AE_OK;
 112         case ACPI_RESOURCE_TYPE_IRQ:
 113                 {
 114                         struct acpi_resource_irq *p = &resource->data.irq;
 115                         if (!p || !p->interrupt_count) {
 116                                 printk(KERN_WARNING PREFIX "Blank IRQ resource\n");
 117                                 return AE_OK;
 118                         }
 119                         for (i = 0;
 120                              (i < p->interrupt_count
 121                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 122                                 if (!p->interrupts[i]) {
 123                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
 124                                                       p->interrupts[i]);
 125                                         continue;
 126                                 }
 127                                 link->irq.possible[i] = p->interrupts[i];
 128                                 link->irq.possible_count++;
 129                         }
 130                         link->irq.triggering = p->triggering;
 131                         link->irq.polarity = p->polarity;
 132                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 133                         break;
 134                 }
 135         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 136                 {
 137                         struct acpi_resource_extended_irq *p =
 138                             &resource->data.extended_irq;
 139                         if (!p || !p->interrupt_count) {
 140                                 printk(KERN_WARNING PREFIX
 141                                               "Blank EXT IRQ resource\n");
 142                                 return AE_OK;
 143                         }
 144                         for (i = 0;
 145                              (i < p->interrupt_count
 146                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 147                                 if (!p->interrupts[i]) {
 148                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
 149                                                       p->interrupts[i]);
 150                                         continue;
 151                                 }
 152                                 link->irq.possible[i] = p->interrupts[i];
 153                                 link->irq.possible_count++;
 154                         }
 155                         link->irq.triggering = p->triggering;
 156                         link->irq.polarity = p->polarity;
 157                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 158                         break;
 159                 }
 160         default:
 161                 printk(KERN_ERR PREFIX "Resource is not an IRQ entry\n");
 162                 return AE_OK;
 163         }
 164
 165         return AE_CTRL_TERMINATE;
 166 }
 167
 168 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 169 {
 170         acpi_status status;
 171
 172
 173         if (!link)
 174                 return -EINVAL;
 175
 176         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 177                                      acpi_pci_link_check_possible, link);
 178         if (ACPI_FAILURE(status)) {
 179                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 180                 return -ENODEV;
 181         }
 182
 183         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 184                           "Found %d possible IRQs\n",
 185                           link->irq.possible_count));
 186
 187         return 0;
 188 }
 189
 190 static acpi_status
 191 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
 192 {
 193         int *irq = (int *)context;
 194
 195
 196         switch (resource->type) {
 197         case ACPI_RESOURCE_TYPE_IRQ:
 198                 {
 199                         struct acpi_resource_irq *p = &resource->data.irq;
 200                         if (!p || !p->interrupt_count) {
 201                                 /*
 202                                  * IRQ descriptors may have no IRQ# bits set,
 203                                  * particularly those those w/ _STA disabled
 204                                  */
 205                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 206                                                   "Blank IRQ resource\n"));
 207                                 return AE_OK;
 208                         }
 209                         *irq = p->interrupts[0];
 210                         break;
 211                 }
 212         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 213                 {
 214                         struct acpi_resource_extended_irq *p =
 215                             &resource->data.extended_irq;
 216                         if (!p || !p->interrupt_count) {
 217                                 /*
 218                                  * extended IRQ descriptors must
 219                                  * return at least 1 IRQ
 220                                  */
 221                                 printk(KERN_WARNING PREFIX
 222                                               "Blank EXT IRQ resource\n");
 223                                 return AE_OK;
 224                         }
 225                         *irq = p->interrupts[0];
 226                         break;
 227                 }
 228                 break;
 229         default:
 230                 printk(KERN_ERR PREFIX "Resource %d isn't an IRQ\n", resource->type);
 231         case ACPI_RESOURCE_TYPE_END_TAG:
 232                 return AE_OK;
 233         }
 234         return AE_CTRL_TERMINATE;
 235 }
 236
 237 /*
 238  * Run _CRS and set link->irq.active
 239  *
 240  * return value:
 241  * 0 - success
 242  * !0 - failure
 243  */
 244 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 245 {
 246         int result = 0;
 247         acpi_status status = AE_OK;
 248         int irq = 0;
 249
 250         if (!link)
 251                 return -EINVAL;
 252
 253         link->irq.active = 0;
 254
 255         /* in practice, status disabled is meaningless, ignore it */
 256         if (acpi_strict) {
 257                 /* Query _STA, set link->device->status */
 258                 result = acpi_bus_get_status(link->device);
 259                 if (result) {
 260                         printk(KERN_ERR PREFIX "Unable to read status\n");
 261                         goto end;
 262                 }
 263
 264                 if (!link->device->status.enabled) {
 265                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 266                         return 0;
 267                 }
 268         }
 269
 270         /*
 271          * Query and parse _CRS to get the current IRQ assignment.
 272          */
 273
 274         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 275                                      acpi_pci_link_check_current, &irq);
 276         if (ACPI_FAILURE(status)) {
 277                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 278                 result = -ENODEV;
 279                 goto end;
 280         }
 281
 282         if (acpi_strict && !irq) {
 283                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 284                 result = -ENODEV;
 285         }
 286
 287         link->irq.active = irq;
 288
 289         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 290
 291       end:
 292         return result;
 293 }
 294
 295 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 296 {
 297         int result = 0;
 298         acpi_status status = AE_OK;
 299         struct {
 300                 struct acpi_resource res;
 301                 struct acpi_resource end;
 302         } *resource;
 303         struct acpi_buffer buffer = { 0, NULL };
 304
 305
 306         if (!link || !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
 358         /* Attempt to set the resource */
 359         status = acpi_set_current_resources(link->device->handle, &buffer);
 360
 361         /* check for total failure */
 362         if (ACPI_FAILURE(status)) {
 363                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 364                 result = -ENODEV;
 365                 goto end;
 366         }
 367
 368         /* Query _STA, set device->status */
 369         result = acpi_bus_get_status(link->device);
 370         if (result) {
 371                 printk(KERN_ERR PREFIX "Unable to read status\n");
 372                 goto end;
 373         }
 374         if (!link->device->status.enabled) {
 375                 printk(KERN_WARNING PREFIX
 376                               "%s [%s] disabled and referenced, BIOS bug\n",
 377                               acpi_device_name(link->device),
 378                               acpi_device_bid(link->device));
 379         }
 380
 381         /* Query _CRS, set link->irq.active */
 382         result = acpi_pci_link_get_current(link);
 383         if (result) {
 384                 goto end;
 385         }
 386
 387         /*
 388          * Is current setting not what we set?
 389          * set link->irq.active
 390          */
 391         if (link->irq.active != irq) {
 392                 /*
 393                  * policy: when _CRS doesn't return what we just _SRS
 394                  * assume _SRS worked and override _CRS value.
 395                  */
 396                 printk(KERN_WARNING PREFIX
 397                               "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 398                               acpi_device_name(link->device),
 399                               acpi_device_bid(link->device), link->irq.active, irq);
 400                 link->irq.active = irq;
 401         }
 402
 403         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 404
 405       end:
 406         kfree(resource);
 407         return result;
 408 }
 409
 410 /* --------------------------------------------------------------------------
 411                             PCI Link IRQ Management
 412    -------------------------------------------------------------------------- */
 413
 414 /*
 415  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 416  * Link Devices to move the PIRQs around to minimize sharing.
 417  *
 418  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 419  * that the BIOS has already set to active.  This is necessary because
 420  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 421  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 422  * even if acpi_irq_nobalance is set.
 423  *
 424  * A tables of penalties avoids directing PCI interrupts to well known
 425  * ISA IRQs. Boot params are available to over-ride the default table:
 426  *
 427  * List interrupts that are free for PCI use.
 428  * acpi_irq_pci=n[,m]
 429  *
 430  * List interrupts that should not be used for PCI:
 431  * acpi_irq_isa=n[,m]
 432  *
 433  * Note that PCI IRQ routers have a list of possible IRQs,
 434  * which may not include the IRQs this table says are available.
 435  *
 436  * Since this heuristic can't tell the difference between a link
 437  * that no device will attach to, vs. a link which may be shared
 438  * by multiple active devices -- it is not optimal.
 439  *
 440  * If interrupt performance is that important, get an IO-APIC system
 441  * with a pin dedicated to each device.  Or for that matter, an MSI
 442  * enabled system.
 443  */
 444
 445 #define ACPI_MAX_IRQS           256
 446 #define ACPI_MAX_ISA_IRQ        16
 447
 448 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 449 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 450 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 451 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 452 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 453 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 454
 455 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 456         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 457         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 458         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 459         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 460         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 461         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 462         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 463         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 464         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 465         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 466         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 467         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 468         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 469         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 470         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 471         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 472         /* >IRQ15 */
 473 };
 474
 475 int __init acpi_irq_penalty_init(void)
 476 {
 477         struct list_head *node = NULL;
 478         struct acpi_pci_link *link = NULL;
 479         int i = 0;
 480
 481
 482         /*
 483          * Update penalties to facilitate IRQ balancing.
 484          */
 485         list_for_each(node, &acpi_link.entries) {
 486
 487                 link = list_entry(node, struct acpi_pci_link, node);
 488                 if (!link) {
 489                         printk(KERN_ERR PREFIX "Invalid link context\n");
 490                         continue;
 491                 }
 492
 493                 /*
 494                  * reflect the possible and active irqs in the penalty table --
 495                  * useful for breaking ties.
 496                  */
 497                 if (link->irq.possible_count) {
 498                         int penalty =
 499                             PIRQ_PENALTY_PCI_POSSIBLE /
 500                             link->irq.possible_count;
 501
 502                         for (i = 0; i < link->irq.possible_count; i++) {
 503                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 504                                         acpi_irq_penalty[link->irq.
 505                                                          possible[i]] +=
 506                                             penalty;
 507                         }
 508
 509                 } else if (link->irq.active) {
 510                         acpi_irq_penalty[link->irq.active] +=
 511                             PIRQ_PENALTY_PCI_POSSIBLE;
 512                 }
 513         }
 514         /* Add a penalty for the SCI */
 515         acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
 516
 517         return 0;
 518 }
 519
 520 static int acpi_irq_balance;    /* 0: static, 1: balance */
 521
 522 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 523 {
 524         int irq;
 525         int i;
 526
 527
 528         if (link->irq.initialized) {
 529                 if (link->refcnt == 0)
 530                         /* This means the link is disabled but initialized */
 531                         acpi_pci_link_set(link, link->irq.active);
 532                 return 0;
 533         }
 534
 535         /*
 536          * search for active IRQ in list of possible IRQs.
 537          */
 538         for (i = 0; i < link->irq.possible_count; ++i) {
 539                 if (link->irq.active == link->irq.possible[i])
 540                         break;
 541         }
 542         /*
 543          * forget active IRQ that is not in possible list
 544          */
 545         if (i == link->irq.possible_count) {
 546                 if (acpi_strict)
 547                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 548                                       " in _PRS\n", link->irq.active);
 549                 link->irq.active = 0;
 550         }
 551
 552         /*
 553          * if active found, use it; else pick entry from end of possible list.
 554          */
 555         if (link->irq.active) {
 556                 irq = link->irq.active;
 557         } else {
 558                 irq = link->irq.possible[link->irq.possible_count - 1];
 559         }
 560
 561         if (acpi_irq_balance || !link->irq.active) {
 562                 /*
 563                  * Select the best IRQ.  This is done in reverse to promote
 564                  * the use of IRQs 9, 10, 11, and >15.
 565                  */
 566                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 567                         if (acpi_irq_penalty[irq] >
 568                             acpi_irq_penalty[link->irq.possible[i]])
 569                                 irq = link->irq.possible[i];
 570                 }
 571         }
 572
 573         /* Attempt to enable the link device at this IRQ. */
 574         if (acpi_pci_link_set(link, irq)) {
 575                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 576                             "Try pci=noacpi or acpi=off\n",
 577                             acpi_device_name(link->device),
 578                             acpi_device_bid(link->device));
 579                 return -ENODEV;
 580         } else {
 581                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 582                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 583                        acpi_device_name(link->device),
 584                        acpi_device_bid(link->device), link->irq.active);
 585         }
 586
 587         link->irq.initialized = 1;
 588
 589         return 0;
 590 }
 591
 592 /*
 593  * acpi_pci_link_allocate_irq
 594  * success: return IRQ >= 0
 595  * failure: return -1
 596  */
 597
 598 int
 599 acpi_pci_link_allocate_irq(acpi_handle handle,
 600                            int index,
 601                            int *triggering, int *polarity, char **name)
 602 {
 603         int result = 0;
 604         struct acpi_device *device = NULL;
 605         struct acpi_pci_link *link = NULL;
 606
 607
 608         result = acpi_bus_get_device(handle, &device);
 609         if (result) {
 610                 printk(KERN_ERR PREFIX "Invalid link device\n");
 611                 return -1;
 612         }
 613
 614         link = acpi_driver_data(device);
 615         if (!link) {
 616                 printk(KERN_ERR PREFIX "Invalid link context\n");
 617                 return -1;
 618         }
 619
 620         /* TBD: Support multiple index (IRQ) entries per Link Device */
 621         if (index) {
 622                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 623                 return -1;
 624         }
 625
 626         mutex_lock(&acpi_link_lock);
 627         if (acpi_pci_link_allocate(link)) {
 628                 mutex_unlock(&acpi_link_lock);
 629                 return -1;
 630         }
 631
 632         if (!link->irq.active) {
 633                 mutex_unlock(&acpi_link_lock);
 634                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 635                 return -1;
 636         }
 637         link->refcnt++;
 638         mutex_unlock(&acpi_link_lock);
 639
 640         if (triggering)
 641                 *triggering = link->irq.triggering;
 642         if (polarity)
 643                 *polarity = link->irq.polarity;
 644         if (name)
 645                 *name = acpi_device_bid(link->device);
 646         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 647                           "Link %s is referenced\n",
 648                           acpi_device_bid(link->device)));
 649         return (link->irq.active);
 650 }
 651
 652 /*
 653  * We don't change link's irq information here.  After it is reenabled, we
 654  * continue use the info
 655  */
 656 int acpi_pci_link_free_irq(acpi_handle handle)
 657 {
 658         struct acpi_device *device = NULL;
 659         struct acpi_pci_link *link = NULL;
 660         acpi_status result;
 661
 662
 663         result = acpi_bus_get_device(handle, &device);
 664         if (result) {
 665                 printk(KERN_ERR PREFIX "Invalid link device\n");
 666                 return -1;
 667         }
 668
 669         link = acpi_driver_data(device);
 670         if (!link) {
 671                 printk(KERN_ERR PREFIX "Invalid link context\n");
 672                 return -1;
 673         }
 674
 675         mutex_lock(&acpi_link_lock);
 676         if (!link->irq.initialized) {
 677                 mutex_unlock(&acpi_link_lock);
 678                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 679                 return -1;
 680         }
 681 #ifdef  FUTURE_USE
 682         /*
 683          * The Link reference count allows us to _DISable an unused link
 684          * and suspend time, and set it again  on resume.
 685          * However, 2.6.12 still has irq_router.resume
 686          * which blindly restores the link state.
 687          * So we disable the reference count method
 688          * to prevent duplicate acpi_pci_link_set()
 689          * which would harm some systems
 690          */
 691         link->refcnt--;
 692 #endif
 693         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 694                           "Link %s is dereferenced\n",
 695                           acpi_device_bid(link->device)));
 696
 697         if (link->refcnt == 0) {
 698                 acpi_ut_evaluate_object(link->device->handle, "_DIS", 0, NULL);
 699         }
 700         mutex_unlock(&acpi_link_lock);
 701         return (link->irq.active);
 702 }
 703
 704 /* --------------------------------------------------------------------------
 705                                  Driver Interface
 706    -------------------------------------------------------------------------- */
 707
 708 static int acpi_pci_link_add(struct acpi_device *device)
 709 {
 710         int result = 0;
 711         struct acpi_pci_link *link = NULL;
 712         int i = 0;
 713         int found = 0;
 714
 715
 716         if (!device)
 717                 return -EINVAL;
 718
 719         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 720         if (!link)
 721                 return -ENOMEM;
 722
 723         link->device = device;
 724         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 725         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 726         acpi_driver_data(device) = link;
 727
 728         mutex_lock(&acpi_link_lock);
 729         result = acpi_pci_link_get_possible(link);
 730         if (result)
 731                 goto end;
 732
 733         /* query and set link->irq.active */
 734         acpi_pci_link_get_current(link);
 735
 736         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 737                acpi_device_bid(device));
 738         for (i = 0; i < link->irq.possible_count; i++) {
 739                 if (link->irq.active == link->irq.possible[i]) {
 740                         printk(" *%d", link->irq.possible[i]);
 741                         found = 1;
 742                 } else
 743                         printk(" %d", link->irq.possible[i]);
 744         }
 745
 746         printk(")");
 747
 748         if (!found)
 749                 printk(" *%d", link->irq.active);
 750
 751         if (!link->device->status.enabled)
 752                 printk(", disabled.");
 753
 754         printk("\n");
 755
 756         /* TBD: Acquire/release lock */
 757         list_add_tail(&link->node, &acpi_link.entries);
 758         acpi_link.count++;
 759
 760       end:
 761         /* disable all links -- to be activated on use */
 762         acpi_ut_evaluate_object(device->handle, "_DIS", 0, NULL);
 763         mutex_unlock(&acpi_link_lock);
 764
 765         if (result)
 766                 kfree(link);
 767
 768         return result;
 769 }
 770
 771 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 772 {
 773
 774         if (link->refcnt && link->irq.active && link->irq.initialized)
 775                 return (acpi_pci_link_set(link, link->irq.active));
 776         else
 777                 return 0;
 778 }
 779
 780 static int irqrouter_resume(struct sys_device *dev)
 781 {
 782         struct list_head *node = NULL;
 783         struct acpi_pci_link *link = NULL;
 784
 785
 786         /* Make sure SCI is enabled again (Apple firmware bug?) */
 787         acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
 788
 789         list_for_each(node, &acpi_link.entries) {
 790                 link = list_entry(node, struct acpi_pci_link, node);
 791                 if (!link) {
 792                         printk(KERN_ERR PREFIX "Invalid link context\n");
 793                         continue;
 794                 }
 795                 acpi_pci_link_resume(link);
 796         }
 797         return 0;
 798 }
 799
 800 static int acpi_pci_link_remove(struct acpi_device *device, int type)
 801 {
 802         struct acpi_pci_link *link = NULL;
 803
 804
 805         if (!device || !acpi_driver_data(device))
 806                 return -EINVAL;
 807
 808         link = acpi_driver_data(device);
 809
 810         mutex_lock(&acpi_link_lock);
 811         list_del(&link->node);
 812         mutex_unlock(&acpi_link_lock);
 813
 814         kfree(link);
 815
 816         return 0;
 817 }
 818
 819 /*
 820  * modify acpi_irq_penalty[] from cmdline
 821  */
 822 static int __init acpi_irq_penalty_update(char *str, int used)
 823 {
 824         int i;
 825
 826         for (i = 0; i < 16; i++) {
 827                 int retval;
 828                 int irq;
 829
 830                 retval = get_option(&str, &irq);
 831
 832                 if (!retval)
 833                         break;  /* no number found */
 834
 835                 if (irq < 0)
 836                         continue;
 837
 838                 if (irq >= ACPI_MAX_IRQS)
 839                         continue;
 840
 841                 if (used)
 842                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 843                 else
 844                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 845
 846                 if (retval != 2)        /* no next number */
 847                         break;
 848         }
 849         return 1;
 850 }
 851
 852 /*
 853  * We'd like PNP to call this routine for the
 854  * single ISA_USED value for each legacy device.
 855  * But instead it calls us with each POSSIBLE setting.
 856  * There is no ISA_POSSIBLE weight, so we simply use
 857  * the (small) PCI_USING penalty.
 858  */
 859 void acpi_penalize_isa_irq(int irq, int active)
 860 {
 861         if (active)
 862                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 863         else
 864                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 865 }
 866
 867 /*
 868  * Over-ride default table to reserve additional IRQs for use by ISA
 869  * e.g. acpi_irq_isa=5
 870  * Useful for telling ACPI how not to interfere with your ISA sound card.
 871  */
 872 static int __init acpi_irq_isa(char *str)
 873 {
 874         return acpi_irq_penalty_update(str, 1);
 875 }
 876
 877 __setup("acpi_irq_isa=", acpi_irq_isa);
 878
 879 /*
 880  * Over-ride default table to free additional IRQs for use by PCI
 881  * e.g. acpi_irq_pci=7,15
 882  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 883  */
 884 static int __init acpi_irq_pci(char *str)
 885 {
 886         return acpi_irq_penalty_update(str, 0);
 887 }
 888
 889 __setup("acpi_irq_pci=", acpi_irq_pci);
 890
 891 static int __init acpi_irq_nobalance_set(char *str)
 892 {
 893         acpi_irq_balance = 0;
 894         return 1;
 895 }
 896
 897 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 898
 899 int __init acpi_irq_balance_set(char *str)
 900 {
 901         acpi_irq_balance = 1;
 902         return 1;
 903 }
 904
 905 __setup("acpi_irq_balance", acpi_irq_balance_set);
 906
 907 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 908 static struct sysdev_class irqrouter_sysdev_class = {
 909         set_kset_name("irqrouter"),
 910         .resume = irqrouter_resume,
 911 };
 912
 913 static struct sys_device device_irqrouter = {
 914         .id = 0,
 915         .cls = &irqrouter_sysdev_class,
 916 };
 917
 918 static int __init irqrouter_init_sysfs(void)
 919 {
 920         int error;
 921
 922
 923         if (acpi_disabled || acpi_noirq)
 924                 return 0;
 925
 926         error = sysdev_class_register(&irqrouter_sysdev_class);
 927         if (!error)
 928                 error = sysdev_register(&device_irqrouter);
 929
 930         return error;
 931 }
 932
 933 device_initcall(irqrouter_init_sysfs);
 934
 935 static int __init acpi_pci_link_init(void)
 936 {
 937
 938         if (acpi_noirq)
 939                 return 0;
 940
 941         acpi_link.count = 0;
 942         INIT_LIST_HEAD(&acpi_link.entries);
 943
 944         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 945                 return -ENODEV;
 946
 947         return 0;
 948 }
 949
 950 subsys_initcall(acpi_pci_link_init);