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
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44
  45 #define _COMPONENT              ACPI_PCI_COMPONENT
  46 ACPI_MODULE_NAME("pci_link")
  47 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  48 #define ACPI_PCI_LINK_HID               "PNP0C0F"
  49 #define ACPI_PCI_LINK_DRIVER_NAME       "ACPI PCI Interrupt Link Driver"
  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 = ACPI_PCI_LINK_DRIVER_NAME,
  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 edge_level;          /* All IRQs */
  74         u8 active_high_low;     /* 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         acpi_handle handle;
  86         struct acpi_pci_link_irq irq;
  87         int refcnt;
  88 };
  89
  90 static struct {
  91         int count;
  92         struct list_head entries;
  93 } acpi_link;
  94 DECLARE_MUTEX(acpi_link_lock);
  95
  96 /* --------------------------------------------------------------------------
  97                             PCI Link Device Management
  98    -------------------------------------------------------------------------- */
  99
 100 /*
 101  * set context (link) possible list from resource list
 102  */
 103 static acpi_status
 104 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
 105 {
 106         struct acpi_pci_link *link = (struct acpi_pci_link *)context;
 107         u32 i = 0;
 108
 109         ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
 110
 111         switch (resource->type) {
 112         case ACPI_RSTYPE_START_DPF:
 113                 return_ACPI_STATUS(AE_OK);
 114         case ACPI_RSTYPE_IRQ:
 115                 {
 116                         struct acpi_resource_irq *p = &resource->data.irq;
 117                         if (!p || !p->number_of_interrupts) {
 118                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 119                                                   "Blank IRQ resource\n"));
 120                                 return_ACPI_STATUS(AE_OK);
 121                         }
 122                         for (i = 0;
 123                              (i < p->number_of_interrupts
 124                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 125                                 if (!p->interrupts[i]) {
 126                                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 127                                                           "Invalid IRQ %d\n",
 128                                                           p->interrupts[i]));
 129                                         continue;
 130                                 }
 131                                 link->irq.possible[i] = p->interrupts[i];
 132                                 link->irq.possible_count++;
 133                         }
 134                         link->irq.edge_level = p->edge_level;
 135                         link->irq.active_high_low = p->active_high_low;
 136                         link->irq.resource_type = ACPI_RSTYPE_IRQ;
 137                         break;
 138                 }
 139         case ACPI_RSTYPE_EXT_IRQ:
 140                 {
 141                         struct acpi_resource_ext_irq *p =
 142                             &resource->data.extended_irq;
 143                         if (!p || !p->number_of_interrupts) {
 144                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 145                                                   "Blank EXT IRQ resource\n"));
 146                                 return_ACPI_STATUS(AE_OK);
 147                         }
 148                         for (i = 0;
 149                              (i < p->number_of_interrupts
 150                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 151                                 if (!p->interrupts[i]) {
 152                                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 153                                                           "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.edge_level = p->edge_level;
 161                         link->irq.active_high_low = p->active_high_low;
 162                         link->irq.resource_type = ACPI_RSTYPE_EXT_IRQ;
 163                         break;
 164                 }
 165         default:
 166                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 167                                   "Resource is not an IRQ entry\n"));
 168                 return_ACPI_STATUS(AE_OK);
 169         }
 170
 171         return_ACPI_STATUS(AE_CTRL_TERMINATE);
 172 }
 173
 174 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 175 {
 176         acpi_status status;
 177
 178         ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
 179
 180         if (!link)
 181                 return_VALUE(-EINVAL);
 182
 183         status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
 184                                      acpi_pci_link_check_possible, link);
 185         if (ACPI_FAILURE(status)) {
 186                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
 187                 return_VALUE(-ENODEV);
 188         }
 189
 190         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 191                           "Found %d possible IRQs\n",
 192                           link->irq.possible_count));
 193
 194         return_VALUE(0);
 195 }
 196
 197 static acpi_status
 198 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
 199 {
 200         int *irq = (int *)context;
 201
 202         ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
 203
 204         switch (resource->type) {
 205         case ACPI_RSTYPE_IRQ:
 206                 {
 207                         struct acpi_resource_irq *p = &resource->data.irq;
 208                         if (!p || !p->number_of_interrupts) {
 209                                 /*
 210                                  * IRQ descriptors may have no IRQ# bits set,
 211                                  * particularly those those w/ _STA disabled
 212                                  */
 213                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 214                                                   "Blank IRQ resource\n"));
 215                                 return_ACPI_STATUS(AE_OK);
 216                         }
 217                         *irq = p->interrupts[0];
 218                         break;
 219                 }
 220         case ACPI_RSTYPE_EXT_IRQ:
 221                 {
 222                         struct acpi_resource_ext_irq *p =
 223                             &resource->data.extended_irq;
 224                         if (!p || !p->number_of_interrupts) {
 225                                 /*
 226                                  * extended IRQ descriptors must
 227                                  * return at least 1 IRQ
 228                                  */
 229                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 230                                                   "Blank EXT IRQ resource\n"));
 231                                 return_ACPI_STATUS(AE_OK);
 232                         }
 233                         *irq = p->interrupts[0];
 234                         break;
 235                 }
 236         default:
 237                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Resource isn't an IRQ\n"));
 238                 return_ACPI_STATUS(AE_OK);
 239         }
 240         return_ACPI_STATUS(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 = AE_OK;
 254         int irq = 0;
 255
 256         ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
 257
 258         if (!link || !link->handle)
 259                 return_VALUE(-EINVAL);
 260
 261         link->irq.active = 0;
 262
 263         /* in practice, status disabled is meaningless, ignore it */
 264         if (acpi_strict) {
 265                 /* Query _STA, set link->device->status */
 266                 result = acpi_bus_get_status(link->device);
 267                 if (result) {
 268                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 269                                           "Unable to read status\n"));
 270                         goto end;
 271                 }
 272
 273                 if (!link->device->status.enabled) {
 274                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 275                         return_VALUE(0);
 276                 }
 277         }
 278
 279         /*
 280          * Query and parse _CRS to get the current IRQ assignment.
 281          */
 282
 283         status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
 284                                      acpi_pci_link_check_current, &irq);
 285         if (ACPI_FAILURE(status)) {
 286                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
 287                 result = -ENODEV;
 288                 goto end;
 289         }
 290
 291         if (acpi_strict && !irq) {
 292                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
 293                 result = -ENODEV;
 294         }
 295
 296         link->irq.active = irq;
 297
 298         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 299
 300       end:
 301         return_VALUE(result);
 302 }
 303
 304 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 305 {
 306         int result = 0;
 307         acpi_status status = AE_OK;
 308         struct {
 309                 struct acpi_resource res;
 310                 struct acpi_resource end;
 311         } *resource;
 312         struct acpi_buffer buffer = { 0, NULL };
 313
 314         ACPI_FUNCTION_TRACE("acpi_pci_link_set");
 315
 316         if (!link || !irq)
 317                 return_VALUE(-EINVAL);
 318
 319         resource = kmalloc(sizeof(*resource) + 1, GFP_KERNEL);
 320         if (!resource)
 321                 return_VALUE(-ENOMEM);
 322
 323         memset(resource, 0, sizeof(*resource) + 1);
 324         buffer.length = sizeof(*resource) + 1;
 325         buffer.pointer = resource;
 326
 327         switch (link->irq.resource_type) {
 328         case ACPI_RSTYPE_IRQ:
 329                 resource->res.type = ACPI_RSTYPE_IRQ;
 330                 resource->res.length = sizeof(struct acpi_resource);
 331                 resource->res.data.irq.edge_level = link->irq.edge_level;
 332                 resource->res.data.irq.active_high_low =
 333                     link->irq.active_high_low;
 334                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 335                         resource->res.data.irq.shared_exclusive =
 336                             ACPI_EXCLUSIVE;
 337                 else
 338                         resource->res.data.irq.shared_exclusive = ACPI_SHARED;
 339                 resource->res.data.irq.number_of_interrupts = 1;
 340                 resource->res.data.irq.interrupts[0] = irq;
 341                 break;
 342
 343         case ACPI_RSTYPE_EXT_IRQ:
 344                 resource->res.type = ACPI_RSTYPE_EXT_IRQ;
 345                 resource->res.length = sizeof(struct acpi_resource);
 346                 resource->res.data.extended_irq.producer_consumer =
 347                     ACPI_CONSUMER;
 348                 resource->res.data.extended_irq.edge_level =
 349                     link->irq.edge_level;
 350                 resource->res.data.extended_irq.active_high_low =
 351                     link->irq.active_high_low;
 352                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 353                         resource->res.data.irq.shared_exclusive =
 354                             ACPI_EXCLUSIVE;
 355                 else
 356                         resource->res.data.irq.shared_exclusive = ACPI_SHARED;
 357                 resource->res.data.extended_irq.number_of_interrupts = 1;
 358                 resource->res.data.extended_irq.interrupts[0] = irq;
 359                 /* ignore resource_source, it's optional */
 360                 break;
 361         default:
 362                 printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
 363                 result = -EINVAL;
 364                 goto end;
 365
 366         }
 367         resource->end.type = ACPI_RSTYPE_END_TAG;
 368
 369         /* Attempt to set the resource */
 370         status = acpi_set_current_resources(link->handle, &buffer);
 371
 372         /* check for total failure */
 373         if (ACPI_FAILURE(status)) {
 374                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
 375                 result = -ENODEV;
 376                 goto end;
 377         }
 378
 379         /* Query _STA, set device->status */
 380         result = acpi_bus_get_status(link->device);
 381         if (result) {
 382                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 383                 goto end;
 384         }
 385         if (!link->device->status.enabled) {
 386                 printk(KERN_WARNING PREFIX
 387                        "%s [%s] disabled and referenced, BIOS bug.\n",
 388                        acpi_device_name(link->device),
 389                        acpi_device_bid(link->device));
 390         }
 391
 392         /* Query _CRS, set link->irq.active */
 393         result = acpi_pci_link_get_current(link);
 394         if (result) {
 395                 goto end;
 396         }
 397
 398         /*
 399          * Is current setting not what we set?
 400          * set link->irq.active
 401          */
 402         if (link->irq.active != irq) {
 403                 /*
 404                  * policy: when _CRS doesn't return what we just _SRS
 405                  * assume _SRS worked and override _CRS value.
 406                  */
 407                 printk(KERN_WARNING PREFIX
 408                        "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 409                        acpi_device_name(link->device),
 410                        acpi_device_bid(link->device), link->irq.active, irq);
 411                 link->irq.active = irq;
 412         }
 413
 414         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 415
 416       end:
 417         kfree(resource);
 418         return_VALUE(result);
 419 }
 420
 421 /* --------------------------------------------------------------------------
 422                             PCI Link IRQ Management
 423    -------------------------------------------------------------------------- */
 424
 425 /*
 426  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 427  * Link Devices to move the PIRQs around to minimize sharing.
 428  *
 429  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 430  * that the BIOS has already set to active.  This is necessary because
 431  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 432  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 433  * even if acpi_irq_nobalance is set.
 434  *
 435  * A tables of penalties avoids directing PCI interrupts to well known
 436  * ISA IRQs. Boot params are available to over-ride the default table:
 437  *
 438  * List interrupts that are free for PCI use.
 439  * acpi_irq_pci=n[,m]
 440  *
 441  * List interrupts that should not be used for PCI:
 442  * acpi_irq_isa=n[,m]
 443  *
 444  * Note that PCI IRQ routers have a list of possible IRQs,
 445  * which may not include the IRQs this table says are available.
 446  *
 447  * Since this heuristic can't tell the difference between a link
 448  * that no device will attach to, vs. a link which may be shared
 449  * by multiple active devices -- it is not optimal.
 450  *
 451  * If interrupt performance is that important, get an IO-APIC system
 452  * with a pin dedicated to each device.  Or for that matter, an MSI
 453  * enabled system.
 454  */
 455
 456 #define ACPI_MAX_IRQS           256
 457 #define ACPI_MAX_ISA_IRQ        16
 458
 459 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 460 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 461 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 462 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 463 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 464 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 465
 466 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 467         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 468         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 469         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 470         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 471         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 472         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 473         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 474         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 475         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 476         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 477         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 478         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 479         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 480         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 481         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 482         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 483         /* >IRQ15 */
 484 };
 485
 486 int __init acpi_irq_penalty_init(void)
 487 {
 488         struct list_head *node = NULL;
 489         struct acpi_pci_link *link = NULL;
 490         int i = 0;
 491
 492         ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");
 493
 494         /*
 495          * Update penalties to facilitate IRQ balancing.
 496          */
 497         list_for_each(node, &acpi_link.entries) {
 498
 499                 link = list_entry(node, struct acpi_pci_link, node);
 500                 if (!link) {
 501                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 502                                           "Invalid link context\n"));
 503                         continue;
 504                 }
 505
 506                 /*
 507                  * reflect the possible and active irqs in the penalty table --
 508                  * useful for breaking ties.
 509                  */
 510                 if (link->irq.possible_count) {
 511                         int penalty =
 512                             PIRQ_PENALTY_PCI_POSSIBLE /
 513                             link->irq.possible_count;
 514
 515                         for (i = 0; i < link->irq.possible_count; i++) {
 516                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 517                                         acpi_irq_penalty[link->irq.
 518                                                          possible[i]] +=
 519                                             penalty;
 520                         }
 521
 522                 } else if (link->irq.active) {
 523                         acpi_irq_penalty[link->irq.active] +=
 524                             PIRQ_PENALTY_PCI_POSSIBLE;
 525                 }
 526         }
 527         /* Add a penalty for the SCI */
 528         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 529
 530         return_VALUE(0);
 531 }
 532
 533 static int acpi_irq_balance;    /* 0: static, 1: balance */
 534
 535 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 536 {
 537         int irq;
 538         int i;
 539
 540         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 541
 542         if (link->irq.initialized) {
 543                 if (link->refcnt == 0)
 544                         /* This means the link is disabled but initialized */
 545                         acpi_pci_link_set(link, link->irq.active);
 546                 return_VALUE(0);
 547         }
 548
 549         /*
 550          * search for active IRQ in list of possible IRQs.
 551          */
 552         for (i = 0; i < link->irq.possible_count; ++i) {
 553                 if (link->irq.active == link->irq.possible[i])
 554                         break;
 555         }
 556         /*
 557          * forget active IRQ that is not in possible list
 558          */
 559         if (i == link->irq.possible_count) {
 560                 if (acpi_strict)
 561                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 562                                " in _PRS\n", link->irq.active);
 563                 link->irq.active = 0;
 564         }
 565
 566         /*
 567          * if active found, use it; else pick entry from end of possible list.
 568          */
 569         if (link->irq.active) {
 570                 irq = link->irq.active;
 571         } else {
 572                 irq = link->irq.possible[link->irq.possible_count - 1];
 573         }
 574
 575         if (acpi_irq_balance || !link->irq.active) {
 576                 /*
 577                  * Select the best IRQ.  This is done in reverse to promote
 578                  * the use of IRQs 9, 10, 11, and >15.
 579                  */
 580                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 581                         if (acpi_irq_penalty[irq] >
 582                             acpi_irq_penalty[link->irq.possible[i]])
 583                                 irq = link->irq.possible[i];
 584                 }
 585         }
 586
 587         /* Attempt to enable the link device at this IRQ. */
 588         if (acpi_pci_link_set(link, irq)) {
 589                 printk(PREFIX
 590                        "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
 591                        "Try pci=noacpi or acpi=off\n",
 592                        acpi_device_name(link->device),
 593                        acpi_device_bid(link->device));
 594                 return_VALUE(-ENODEV);
 595         } else {
 596                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 597                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 598                        acpi_device_name(link->device),
 599                        acpi_device_bid(link->device), link->irq.active);
 600         }
 601
 602         link->irq.initialized = 1;
 603
 604         return_VALUE(0);
 605 }
 606
 607 /*
 608  * acpi_pci_link_allocate_irq
 609  * success: return IRQ >= 0
 610  * failure: return -1
 611  */
 612
 613 int
 614 acpi_pci_link_allocate_irq(acpi_handle handle,
 615                            int index,
 616                            int *edge_level, int *active_high_low, char **name)
 617 {
 618         int result = 0;
 619         struct acpi_device *device = NULL;
 620         struct acpi_pci_link *link = NULL;
 621
 622         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate_irq");
 623
 624         result = acpi_bus_get_device(handle, &device);
 625         if (result) {
 626                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 627                 return_VALUE(-1);
 628         }
 629
 630         link = (struct acpi_pci_link *)acpi_driver_data(device);
 631         if (!link) {
 632                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 633                 return_VALUE(-1);
 634         }
 635
 636         /* TBD: Support multiple index (IRQ) entries per Link Device */
 637         if (index) {
 638                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
 639                 return_VALUE(-1);
 640         }
 641
 642         down(&acpi_link_lock);
 643         if (acpi_pci_link_allocate(link)) {
 644                 up(&acpi_link_lock);
 645                 return_VALUE(-1);
 646         }
 647
 648         if (!link->irq.active) {
 649                 up(&acpi_link_lock);
 650                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
 651                 return_VALUE(-1);
 652         }
 653         link->refcnt++;
 654         up(&acpi_link_lock);
 655
 656         if (edge_level)
 657                 *edge_level = link->irq.edge_level;
 658         if (active_high_low)
 659                 *active_high_low = link->irq.active_high_low;
 660         if (name)
 661                 *name = acpi_device_bid(link->device);
 662         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 663                           "Link %s is referenced\n",
 664                           acpi_device_bid(link->device)));
 665         return_VALUE(link->irq.active);
 666 }
 667
 668 /*
 669  * We don't change link's irq information here.  After it is reenabled, we
 670  * continue use the info
 671  */
 672 int acpi_pci_link_free_irq(acpi_handle handle)
 673 {
 674         struct acpi_device *device = NULL;
 675         struct acpi_pci_link *link = NULL;
 676         acpi_status result;
 677
 678         ACPI_FUNCTION_TRACE("acpi_pci_link_free_irq");
 679
 680         result = acpi_bus_get_device(handle, &device);
 681         if (result) {
 682                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 683                 return_VALUE(-1);
 684         }
 685
 686         link = (struct acpi_pci_link *)acpi_driver_data(device);
 687         if (!link) {
 688                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 689                 return_VALUE(-1);
 690         }
 691
 692         down(&acpi_link_lock);
 693         if (!link->irq.initialized) {
 694                 up(&acpi_link_lock);
 695                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link isn't initialized\n"));
 696                 return_VALUE(-1);
 697         }
 698 #ifdef  FUTURE_USE
 699         /*
 700          * The Link reference count allows us to _DISable an unused link
 701          * and suspend time, and set it again  on resume.
 702          * However, 2.6.12 still has irq_router.resume
 703          * which blindly restores the link state.
 704          * So we disable the reference count method
 705          * to prevent duplicate acpi_pci_link_set()
 706          * which would harm some systems
 707          */
 708         link->refcnt--;
 709 #endif
 710         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 711                           "Link %s is dereferenced\n",
 712                           acpi_device_bid(link->device)));
 713
 714         if (link->refcnt == 0) {
 715                 acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 716         }
 717         up(&acpi_link_lock);
 718         return_VALUE(link->irq.active);
 719 }
 720
 721 /* --------------------------------------------------------------------------
 722                                  Driver Interface
 723    -------------------------------------------------------------------------- */
 724
 725 static int acpi_pci_link_add(struct acpi_device *device)
 726 {
 727         int result = 0;
 728         struct acpi_pci_link *link = NULL;
 729         int i = 0;
 730         int found = 0;
 731
 732         ACPI_FUNCTION_TRACE("acpi_pci_link_add");
 733
 734         if (!device)
 735                 return_VALUE(-EINVAL);
 736
 737         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 738         if (!link)
 739                 return_VALUE(-ENOMEM);
 740         memset(link, 0, sizeof(struct acpi_pci_link));
 741
 742         link->device = device;
 743         link->handle = device->handle;
 744         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 745         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 746         acpi_driver_data(device) = link;
 747
 748         down(&acpi_link_lock);
 749         result = acpi_pci_link_get_possible(link);
 750         if (result)
 751                 goto end;
 752
 753         /* query and set link->irq.active */
 754         acpi_pci_link_get_current(link);
 755
 756         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 757                acpi_device_bid(device));
 758         for (i = 0; i < link->irq.possible_count; i++) {
 759                 if (link->irq.active == link->irq.possible[i]) {
 760                         printk(" *%d", link->irq.possible[i]);
 761                         found = 1;
 762                 } else
 763                         printk(" %d", link->irq.possible[i]);
 764         }
 765
 766         printk(")");
 767
 768         if (!found)
 769                 printk(" *%d", link->irq.active);
 770
 771         if (!link->device->status.enabled)
 772                 printk(", disabled.");
 773
 774         printk("\n");
 775
 776         /* TBD: Acquire/release lock */
 777         list_add_tail(&link->node, &acpi_link.entries);
 778         acpi_link.count++;
 779
 780       end:
 781         /* disable all links -- to be activated on use */
 782         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 783         up(&acpi_link_lock);
 784
 785         if (result)
 786                 kfree(link);
 787
 788         return_VALUE(result);
 789 }
 790
 791 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 792 {
 793         ACPI_FUNCTION_TRACE("acpi_pci_link_resume");
 794
 795         if (link->refcnt && link->irq.active && link->irq.initialized)
 796                 return_VALUE(acpi_pci_link_set(link, link->irq.active));
 797         else
 798                 return_VALUE(0);
 799 }
 800
 801 /*
 802  * FIXME: this is a workaround to avoid nasty warning.  It will be removed
 803  * after every device calls pci_disable_device in .resume.
 804  */
 805 int acpi_in_resume;
 806 static int irqrouter_resume(struct sys_device *dev)
 807 {
 808         struct list_head *node = NULL;
 809         struct acpi_pci_link *link = NULL;
 810
 811         ACPI_FUNCTION_TRACE("irqrouter_resume");
 812
 813         acpi_in_resume = 1;
 814         list_for_each(node, &acpi_link.entries) {
 815                 link = list_entry(node, struct acpi_pci_link, node);
 816                 if (!link) {
 817                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 818                                           "Invalid link context\n"));
 819                         continue;
 820                 }
 821                 acpi_pci_link_resume(link);
 822         }
 823         acpi_in_resume = 0;
 824         return_VALUE(0);
 825 }
 826
 827 static int acpi_pci_link_remove(struct acpi_device *device, int type)
 828 {
 829         struct acpi_pci_link *link = NULL;
 830
 831         ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
 832
 833         if (!device || !acpi_driver_data(device))
 834                 return_VALUE(-EINVAL);
 835
 836         link = (struct acpi_pci_link *)acpi_driver_data(device);
 837
 838         down(&acpi_link_lock);
 839         list_del(&link->node);
 840         up(&acpi_link_lock);
 841
 842         kfree(link);
 843
 844         return_VALUE(0);
 845 }
 846
 847 /*
 848  * modify acpi_irq_penalty[] from cmdline
 849  */
 850 static int __init acpi_irq_penalty_update(char *str, int used)
 851 {
 852         int i;
 853
 854         for (i = 0; i < 16; i++) {
 855                 int retval;
 856                 int irq;
 857
 858                 retval = get_option(&str, &irq);
 859
 860                 if (!retval)
 861                         break;  /* no number found */
 862
 863                 if (irq < 0)
 864                         continue;
 865
 866                 if (irq >= ACPI_MAX_IRQS)
 867                         continue;
 868
 869                 if (used)
 870                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 871                 else
 872                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 873
 874                 if (retval != 2)        /* no next number */
 875                         break;
 876         }
 877         return 1;
 878 }
 879
 880 /*
 881  * We'd like PNP to call this routine for the
 882  * single ISA_USED value for each legacy device.
 883  * But instead it calls us with each POSSIBLE setting.
 884  * There is no ISA_POSSIBLE weight, so we simply use
 885  * the (small) PCI_USING penalty.
 886  */
 887 void acpi_penalize_isa_irq(int irq, int active)
 888 {
 889         if (active)
 890                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 891         else
 892                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 893 }
 894
 895 /*
 896  * Over-ride default table to reserve additional IRQs for use by ISA
 897  * e.g. acpi_irq_isa=5
 898  * Useful for telling ACPI how not to interfere with your ISA sound card.
 899  */
 900 static int __init acpi_irq_isa(char *str)
 901 {
 902         return acpi_irq_penalty_update(str, 1);
 903 }
 904
 905 __setup("acpi_irq_isa=", acpi_irq_isa);
 906
 907 /*
 908  * Over-ride default table to free additional IRQs for use by PCI
 909  * e.g. acpi_irq_pci=7,15
 910  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 911  */
 912 static int __init acpi_irq_pci(char *str)
 913 {
 914         return acpi_irq_penalty_update(str, 0);
 915 }
 916
 917 __setup("acpi_irq_pci=", acpi_irq_pci);
 918
 919 static int __init acpi_irq_nobalance_set(char *str)
 920 {
 921         acpi_irq_balance = 0;
 922         return 1;
 923 }
 924
 925 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 926
 927 int __init acpi_irq_balance_set(char *str)
 928 {
 929         acpi_irq_balance = 1;
 930         return 1;
 931 }
 932
 933 __setup("acpi_irq_balance", acpi_irq_balance_set);
 934
 935 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 936 static struct sysdev_class irqrouter_sysdev_class = {
 937         set_kset_name("irqrouter"),
 938         .resume = irqrouter_resume,
 939 };
 940
 941 static struct sys_device device_irqrouter = {
 942         .id = 0,
 943         .cls = &irqrouter_sysdev_class,
 944 };
 945
 946 static int __init irqrouter_init_sysfs(void)
 947 {
 948         int error;
 949
 950         ACPI_FUNCTION_TRACE("irqrouter_init_sysfs");
 951
 952         if (acpi_disabled || acpi_noirq)
 953                 return_VALUE(0);
 954
 955         error = sysdev_class_register(&irqrouter_sysdev_class);
 956         if (!error)
 957                 error = sysdev_register(&device_irqrouter);
 958
 959         return_VALUE(error);
 960 }
 961
 962 device_initcall(irqrouter_init_sysfs);
 963
 964 static int __init acpi_pci_link_init(void)
 965 {
 966         ACPI_FUNCTION_TRACE("acpi_pci_link_init");
 967
 968         if (acpi_noirq)
 969                 return_VALUE(0);
 970
 971         acpi_link.count = 0;
 972         INIT_LIST_HEAD(&acpi_link.entries);
 973
 974         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 975                 return_VALUE(-ENODEV);
 976
 977         return_VALUE(0);
 978 }
 979
 980 subsys_initcall(acpi_pci_link_init);