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_DRIVER_NAME       "ACPI PCI Interrupt Link Driver"
  51 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  52 #define ACPI_PCI_LINK_FILE_INFO         "info"
  53 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  54 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  55 static int acpi_pci_link_add(struct acpi_device *device);
  56 static int acpi_pci_link_remove(struct acpi_device *device, int type);
  57
  58 static struct acpi_driver acpi_pci_link_driver = {
  59         .name = ACPI_PCI_LINK_DRIVER_NAME,
  60         .class = ACPI_PCI_LINK_CLASS,
  61         .ids = ACPI_PCI_LINK_HID,
  62         .ops = {
  63                 .add = acpi_pci_link_add,
  64                 .remove = acpi_pci_link_remove,
  65                 },
  66 };
  67
  68 /*
  69  * If a link is initialized, we never change its active and initialized
  70  * later even the link is disable. Instead, we just repick the active irq
  71  */
  72 struct acpi_pci_link_irq {
  73         u8 active;              /* Current IRQ */
  74         u8 triggering;          /* All IRQs */
  75         u8 polarity;    /* All IRQs */
  76         u8 resource_type;
  77         u8 possible_count;
  78         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  79         u8 initialized:1;
  80         u8 reserved:7;
  81 };
  82
  83 struct acpi_pci_link {
  84         struct list_head node;
  85         struct acpi_device *device;
  86         acpi_handle handle;
  87         struct acpi_pci_link_irq irq;
  88         int refcnt;
  89 };
  90
  91 static struct {
  92         int count;
  93         struct list_head entries;
  94 } acpi_link;
  95 DEFINE_MUTEX(acpi_link_lock);
  96
  97 /* --------------------------------------------------------------------------
  98                             PCI Link Device Management
  99    -------------------------------------------------------------------------- */
 100
 101 /*
 102  * set context (link) possible list from resource list
 103  */
 104 static acpi_status
 105 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
 106 {
 107         struct acpi_pci_link *link = (struct acpi_pci_link *)context;
 108         u32 i = 0;
 109
 110         ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
 111
 112         switch (resource->type) {
 113         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 114                 return_ACPI_STATUS(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_WARN,
 120                                                   "Blank IRQ resource\n"));
 121                                 return_ACPI_STATUS(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                                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 128                                                           "Invalid IRQ %d\n",
 129                                                           p->interrupts[i]));
 130                                         continue;
 131                                 }
 132                                 link->irq.possible[i] = p->interrupts[i];
 133                                 link->irq.possible_count++;
 134                         }
 135                         link->irq.triggering = p->triggering;
 136                         link->irq.polarity = p->polarity;
 137                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 138                         break;
 139                 }
 140         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 141                 {
 142                         struct acpi_resource_extended_irq *p =
 143                             &resource->data.extended_irq;
 144                         if (!p || !p->interrupt_count) {
 145                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 146                                                   "Blank EXT IRQ resource\n"));
 147                                 return_ACPI_STATUS(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                                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 154                                                           "Invalid 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                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 168                                   "Resource is not an IRQ entry\n"));
 169                 return_ACPI_STATUS(AE_OK);
 170         }
 171
 172         return_ACPI_STATUS(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         ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
 180
 181         if (!link)
 182                 return_VALUE(-EINVAL);
 183
 184         status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
 185                                      acpi_pci_link_check_possible, link);
 186         if (ACPI_FAILURE(status)) {
 187                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
 188                 return_VALUE(-ENODEV);
 189         }
 190
 191         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 192                           "Found %d possible IRQs\n",
 193                           link->irq.possible_count));
 194
 195         return_VALUE(0);
 196 }
 197
 198 static acpi_status
 199 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
 200 {
 201         int *irq = (int *)context;
 202
 203         ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
 204
 205         switch (resource->type) {
 206         case ACPI_RESOURCE_TYPE_IRQ:
 207                 {
 208                         struct acpi_resource_irq *p = &resource->data.irq;
 209                         if (!p || !p->interrupt_count) {
 210                                 /*
 211                                  * IRQ descriptors may have no IRQ# bits set,
 212                                  * particularly those those w/ _STA disabled
 213                                  */
 214                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 215                                                   "Blank IRQ resource\n"));
 216                                 return_ACPI_STATUS(AE_OK);
 217                         }
 218                         *irq = p->interrupts[0];
 219                         break;
 220                 }
 221         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 222                 {
 223                         struct acpi_resource_extended_irq *p =
 224                             &resource->data.extended_irq;
 225                         if (!p || !p->interrupt_count) {
 226                                 /*
 227                                  * extended IRQ descriptors must
 228                                  * return at least 1 IRQ
 229                                  */
 230                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 231                                                   "Blank EXT IRQ resource\n"));
 232                                 return_ACPI_STATUS(AE_OK);
 233                         }
 234                         *irq = p->interrupts[0];
 235                         break;
 236                 }
 237                 break;
 238         default:
 239                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Resource %d isn't an IRQ\n", resource->type));
 240         case ACPI_RESOURCE_TYPE_END_TAG:
 241                 return_ACPI_STATUS(AE_OK);
 242         }
 243         return_ACPI_STATUS(AE_CTRL_TERMINATE);
 244 }
 245
 246 /*
 247  * Run _CRS and set link->irq.active
 248  *
 249  * return value:
 250  * 0 - success
 251  * !0 - failure
 252  */
 253 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 254 {
 255         int result = 0;
 256         acpi_status status = AE_OK;
 257         int irq = 0;
 258
 259         ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
 260
 261         if (!link || !link->handle)
 262                 return_VALUE(-EINVAL);
 263
 264         link->irq.active = 0;
 265
 266         /* in practice, status disabled is meaningless, ignore it */
 267         if (acpi_strict) {
 268                 /* Query _STA, set link->device->status */
 269                 result = acpi_bus_get_status(link->device);
 270                 if (result) {
 271                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 272                                           "Unable to read status\n"));
 273                         goto end;
 274                 }
 275
 276                 if (!link->device->status.enabled) {
 277                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 278                         return_VALUE(0);
 279                 }
 280         }
 281
 282         /*
 283          * Query and parse _CRS to get the current IRQ assignment.
 284          */
 285
 286         status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
 287                                      acpi_pci_link_check_current, &irq);
 288         if (ACPI_FAILURE(status)) {
 289                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
 290                 result = -ENODEV;
 291                 goto end;
 292         }
 293
 294         if (acpi_strict && !irq) {
 295                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
 296                 result = -ENODEV;
 297         }
 298
 299         link->irq.active = irq;
 300
 301         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 302
 303       end:
 304         return_VALUE(result);
 305 }
 306
 307 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 308 {
 309         int result = 0;
 310         acpi_status status = AE_OK;
 311         struct {
 312                 struct acpi_resource res;
 313                 struct acpi_resource end;
 314         } *resource;
 315         struct acpi_buffer buffer = { 0, NULL };
 316
 317         ACPI_FUNCTION_TRACE("acpi_pci_link_set");
 318
 319         if (!link || !irq)
 320                 return_VALUE(-EINVAL);
 321
 322         resource = kmalloc(sizeof(*resource) + 1, GFP_ATOMIC);
 323         if (!resource)
 324                 return_VALUE(-ENOMEM);
 325
 326         memset(resource, 0, sizeof(*resource) + 1);
 327         buffer.length = sizeof(*resource) + 1;
 328         buffer.pointer = resource;
 329
 330         switch (link->irq.resource_type) {
 331         case ACPI_RESOURCE_TYPE_IRQ:
 332                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 333                 resource->res.length = sizeof(struct acpi_resource);
 334                 resource->res.data.irq.triggering = link->irq.triggering;
 335                 resource->res.data.irq.polarity =
 336                     link->irq.polarity;
 337                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 338                         resource->res.data.irq.sharable =
 339                             ACPI_EXCLUSIVE;
 340                 else
 341                         resource->res.data.irq.sharable = ACPI_SHARED;
 342                 resource->res.data.irq.interrupt_count = 1;
 343                 resource->res.data.irq.interrupts[0] = irq;
 344                 break;
 345
 346         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 347                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 348                 resource->res.length = sizeof(struct acpi_resource);
 349                 resource->res.data.extended_irq.producer_consumer =
 350                     ACPI_CONSUMER;
 351                 resource->res.data.extended_irq.triggering =
 352                     link->irq.triggering;
 353                 resource->res.data.extended_irq.polarity =
 354                     link->irq.polarity;
 355                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 356                         resource->res.data.irq.sharable =
 357                             ACPI_EXCLUSIVE;
 358                 else
 359                         resource->res.data.irq.sharable = ACPI_SHARED;
 360                 resource->res.data.extended_irq.interrupt_count = 1;
 361                 resource->res.data.extended_irq.interrupts[0] = irq;
 362                 /* ignore resource_source, it's optional */
 363                 break;
 364         default:
 365                 printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
 366                 result = -EINVAL;
 367                 goto end;
 368
 369         }
 370         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 371
 372         /* Attempt to set the resource */
 373         status = acpi_set_current_resources(link->handle, &buffer);
 374
 375         /* check for total failure */
 376         if (ACPI_FAILURE(status)) {
 377                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
 378                 result = -ENODEV;
 379                 goto end;
 380         }
 381
 382         /* Query _STA, set device->status */
 383         result = acpi_bus_get_status(link->device);
 384         if (result) {
 385                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 386                 goto end;
 387         }
 388         if (!link->device->status.enabled) {
 389                 printk(KERN_WARNING PREFIX
 390                        "%s [%s] disabled and referenced, BIOS bug.\n",
 391                        acpi_device_name(link->device),
 392                        acpi_device_bid(link->device));
 393         }
 394
 395         /* Query _CRS, set link->irq.active */
 396         result = acpi_pci_link_get_current(link);
 397         if (result) {
 398                 goto end;
 399         }
 400
 401         /*
 402          * Is current setting not what we set?
 403          * set link->irq.active
 404          */
 405         if (link->irq.active != irq) {
 406                 /*
 407                  * policy: when _CRS doesn't return what we just _SRS
 408                  * assume _SRS worked and override _CRS value.
 409                  */
 410                 printk(KERN_WARNING PREFIX
 411                        "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 412                        acpi_device_name(link->device),
 413                        acpi_device_bid(link->device), link->irq.active, irq);
 414                 link->irq.active = irq;
 415         }
 416
 417         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 418
 419       end:
 420         kfree(resource);
 421         return_VALUE(result);
 422 }
 423
 424 /* --------------------------------------------------------------------------
 425                             PCI Link IRQ Management
 426    -------------------------------------------------------------------------- */
 427
 428 /*
 429  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 430  * Link Devices to move the PIRQs around to minimize sharing.
 431  *
 432  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 433  * that the BIOS has already set to active.  This is necessary because
 434  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 435  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 436  * even if acpi_irq_nobalance is set.
 437  *
 438  * A tables of penalties avoids directing PCI interrupts to well known
 439  * ISA IRQs. Boot params are available to over-ride the default table:
 440  *
 441  * List interrupts that are free for PCI use.
 442  * acpi_irq_pci=n[,m]
 443  *
 444  * List interrupts that should not be used for PCI:
 445  * acpi_irq_isa=n[,m]
 446  *
 447  * Note that PCI IRQ routers have a list of possible IRQs,
 448  * which may not include the IRQs this table says are available.
 449  *
 450  * Since this heuristic can't tell the difference between a link
 451  * that no device will attach to, vs. a link which may be shared
 452  * by multiple active devices -- it is not optimal.
 453  *
 454  * If interrupt performance is that important, get an IO-APIC system
 455  * with a pin dedicated to each device.  Or for that matter, an MSI
 456  * enabled system.
 457  */
 458
 459 #define ACPI_MAX_IRQS           256
 460 #define ACPI_MAX_ISA_IRQ        16
 461
 462 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 463 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 464 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 465 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 466 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 467 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 468
 469 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 470         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 471         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 472         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 473         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 474         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 475         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 476         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 477         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 478         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 479         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 480         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 481         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 482         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 483         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 484         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 485         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 486         /* >IRQ15 */
 487 };
 488
 489 int __init acpi_irq_penalty_init(void)
 490 {
 491         struct list_head *node = NULL;
 492         struct acpi_pci_link *link = NULL;
 493         int i = 0;
 494
 495         ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");
 496
 497         /*
 498          * Update penalties to facilitate IRQ balancing.
 499          */
 500         list_for_each(node, &acpi_link.entries) {
 501
 502                 link = list_entry(node, struct acpi_pci_link, node);
 503                 if (!link) {
 504                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 505                                           "Invalid link context\n"));
 506                         continue;
 507                 }
 508
 509                 /*
 510                  * reflect the possible and active irqs in the penalty table --
 511                  * useful for breaking ties.
 512                  */
 513                 if (link->irq.possible_count) {
 514                         int penalty =
 515                             PIRQ_PENALTY_PCI_POSSIBLE /
 516                             link->irq.possible_count;
 517
 518                         for (i = 0; i < link->irq.possible_count; i++) {
 519                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 520                                         acpi_irq_penalty[link->irq.
 521                                                          possible[i]] +=
 522                                             penalty;
 523                         }
 524
 525                 } else if (link->irq.active) {
 526                         acpi_irq_penalty[link->irq.active] +=
 527                             PIRQ_PENALTY_PCI_POSSIBLE;
 528                 }
 529         }
 530         /* Add a penalty for the SCI */
 531         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 532
 533         return_VALUE(0);
 534 }
 535
 536 static int acpi_irq_balance;    /* 0: static, 1: balance */
 537
 538 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 539 {
 540         int irq;
 541         int i;
 542
 543         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 544
 545         if (link->irq.initialized) {
 546                 if (link->refcnt == 0)
 547                         /* This means the link is disabled but initialized */
 548                         acpi_pci_link_set(link, link->irq.active);
 549                 return_VALUE(0);
 550         }
 551
 552         /*
 553          * search for active IRQ in list of possible IRQs.
 554          */
 555         for (i = 0; i < link->irq.possible_count; ++i) {
 556                 if (link->irq.active == link->irq.possible[i])
 557                         break;
 558         }
 559         /*
 560          * forget active IRQ that is not in possible list
 561          */
 562         if (i == link->irq.possible_count) {
 563                 if (acpi_strict)
 564                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 565                                " in _PRS\n", link->irq.active);
 566                 link->irq.active = 0;
 567         }
 568
 569         /*
 570          * if active found, use it; else pick entry from end of possible list.
 571          */
 572         if (link->irq.active) {
 573                 irq = link->irq.active;
 574         } else {
 575                 irq = link->irq.possible[link->irq.possible_count - 1];
 576         }
 577
 578         if (acpi_irq_balance || !link->irq.active) {
 579                 /*
 580                  * Select the best IRQ.  This is done in reverse to promote
 581                  * the use of IRQs 9, 10, 11, and >15.
 582                  */
 583                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 584                         if (acpi_irq_penalty[irq] >
 585                             acpi_irq_penalty[link->irq.possible[i]])
 586                                 irq = link->irq.possible[i];
 587                 }
 588         }
 589
 590         /* Attempt to enable the link device at this IRQ. */
 591         if (acpi_pci_link_set(link, irq)) {
 592                 printk(PREFIX
 593                        "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
 594                        "Try pci=noacpi or acpi=off\n",
 595                        acpi_device_name(link->device),
 596                        acpi_device_bid(link->device));
 597                 return_VALUE(-ENODEV);
 598         } else {
 599                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 600                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 601                        acpi_device_name(link->device),
 602                        acpi_device_bid(link->device), link->irq.active);
 603         }
 604
 605         link->irq.initialized = 1;
 606
 607         return_VALUE(0);
 608 }
 609
 610 /*
 611  * acpi_pci_link_allocate_irq
 612  * success: return IRQ >= 0
 613  * failure: return -1
 614  */
 615
 616 int
 617 acpi_pci_link_allocate_irq(acpi_handle handle,
 618                            int index,
 619                            int *triggering, int *polarity, char **name)
 620 {
 621         int result = 0;
 622         struct acpi_device *device = NULL;
 623         struct acpi_pci_link *link = NULL;
 624
 625         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate_irq");
 626
 627         result = acpi_bus_get_device(handle, &device);
 628         if (result) {
 629                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 630                 return_VALUE(-1);
 631         }
 632
 633         link = (struct acpi_pci_link *)acpi_driver_data(device);
 634         if (!link) {
 635                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 636                 return_VALUE(-1);
 637         }
 638
 639         /* TBD: Support multiple index (IRQ) entries per Link Device */
 640         if (index) {
 641                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
 642                 return_VALUE(-1);
 643         }
 644
 645         mutex_lock(&acpi_link_lock);
 646         if (acpi_pci_link_allocate(link)) {
 647                 mutex_unlock(&acpi_link_lock);
 648                 return_VALUE(-1);
 649         }
 650
 651         if (!link->irq.active) {
 652                 mutex_unlock(&acpi_link_lock);
 653                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
 654                 return_VALUE(-1);
 655         }
 656         link->refcnt++;
 657         mutex_unlock(&acpi_link_lock);
 658
 659         if (triggering)
 660                 *triggering = link->irq.triggering;
 661         if (polarity)
 662                 *polarity = link->irq.polarity;
 663         if (name)
 664                 *name = acpi_device_bid(link->device);
 665         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 666                           "Link %s is referenced\n",
 667                           acpi_device_bid(link->device)));
 668         return_VALUE(link->irq.active);
 669 }
 670
 671 /*
 672  * We don't change link's irq information here.  After it is reenabled, we
 673  * continue use the info
 674  */
 675 int acpi_pci_link_free_irq(acpi_handle handle)
 676 {
 677         struct acpi_device *device = NULL;
 678         struct acpi_pci_link *link = NULL;
 679         acpi_status result;
 680
 681         ACPI_FUNCTION_TRACE("acpi_pci_link_free_irq");
 682
 683         result = acpi_bus_get_device(handle, &device);
 684         if (result) {
 685                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 686                 return_VALUE(-1);
 687         }
 688
 689         link = (struct acpi_pci_link *)acpi_driver_data(device);
 690         if (!link) {
 691                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 692                 return_VALUE(-1);
 693         }
 694
 695         mutex_lock(&acpi_link_lock);
 696         if (!link->irq.initialized) {
 697                 mutex_unlock(&acpi_link_lock);
 698                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link isn't initialized\n"));
 699                 return_VALUE(-1);
 700         }
 701 #ifdef  FUTURE_USE
 702         /*
 703          * The Link reference count allows us to _DISable an unused link
 704          * and suspend time, and set it again  on resume.
 705          * However, 2.6.12 still has irq_router.resume
 706          * which blindly restores the link state.
 707          * So we disable the reference count method
 708          * to prevent duplicate acpi_pci_link_set()
 709          * which would harm some systems
 710          */
 711         link->refcnt--;
 712 #endif
 713         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 714                           "Link %s is dereferenced\n",
 715                           acpi_device_bid(link->device)));
 716
 717         if (link->refcnt == 0) {
 718                 acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 719         }
 720         mutex_unlock(&acpi_link_lock);
 721         return_VALUE(link->irq.active);
 722 }
 723
 724 /* --------------------------------------------------------------------------
 725                                  Driver Interface
 726    -------------------------------------------------------------------------- */
 727
 728 static int acpi_pci_link_add(struct acpi_device *device)
 729 {
 730         int result = 0;
 731         struct acpi_pci_link *link = NULL;
 732         int i = 0;
 733         int found = 0;
 734
 735         ACPI_FUNCTION_TRACE("acpi_pci_link_add");
 736
 737         if (!device)
 738                 return_VALUE(-EINVAL);
 739
 740         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 741         if (!link)
 742                 return_VALUE(-ENOMEM);
 743         memset(link, 0, sizeof(struct acpi_pci_link));
 744
 745         link->device = device;
 746         link->handle = device->handle;
 747         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 748         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 749         acpi_driver_data(device) = link;
 750
 751         mutex_lock(&acpi_link_lock);
 752         result = acpi_pci_link_get_possible(link);
 753         if (result)
 754                 goto end;
 755
 756         /* query and set link->irq.active */
 757         acpi_pci_link_get_current(link);
 758
 759         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 760                acpi_device_bid(device));
 761         for (i = 0; i < link->irq.possible_count; i++) {
 762                 if (link->irq.active == link->irq.possible[i]) {
 763                         printk(" *%d", link->irq.possible[i]);
 764                         found = 1;
 765                 } else
 766                         printk(" %d", link->irq.possible[i]);
 767         }
 768
 769         printk(")");
 770
 771         if (!found)
 772                 printk(" *%d", link->irq.active);
 773
 774         if (!link->device->status.enabled)
 775                 printk(", disabled.");
 776
 777         printk("\n");
 778
 779         /* TBD: Acquire/release lock */
 780         list_add_tail(&link->node, &acpi_link.entries);
 781         acpi_link.count++;
 782
 783       end:
 784         /* disable all links -- to be activated on use */
 785         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 786         mutex_unlock(&acpi_link_lock);
 787
 788         if (result)
 789                 kfree(link);
 790
 791         return_VALUE(result);
 792 }
 793
 794 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 795 {
 796         ACPI_FUNCTION_TRACE("acpi_pci_link_resume");
 797
 798         if (link->refcnt && link->irq.active && link->irq.initialized)
 799                 return_VALUE(acpi_pci_link_set(link, link->irq.active));
 800         else
 801                 return_VALUE(0);
 802 }
 803
 804 /*
 805  * FIXME: this is a workaround to avoid nasty warning.  It will be removed
 806  * after every device calls pci_disable_device in .resume.
 807  */
 808 int acpi_in_resume;
 809 static int irqrouter_resume(struct sys_device *dev)
 810 {
 811         struct list_head *node = NULL;
 812         struct acpi_pci_link *link = NULL;
 813
 814         ACPI_FUNCTION_TRACE("irqrouter_resume");
 815
 816         /* Make sure SCI is enabled again (Apple firmware bug?) */
 817         acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1, ACPI_MTX_DO_NOT_LOCK);
 818
 819         acpi_in_resume = 1;
 820         list_for_each(node, &acpi_link.entries) {
 821                 link = list_entry(node, struct acpi_pci_link, node);
 822                 if (!link) {
 823                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 824                                           "Invalid link context\n"));
 825                         continue;
 826                 }
 827                 acpi_pci_link_resume(link);
 828         }
 829         acpi_in_resume = 0;
 830         return_VALUE(0);
 831 }
 832
 833 static int acpi_pci_link_remove(struct acpi_device *device, int type)
 834 {
 835         struct acpi_pci_link *link = NULL;
 836
 837         ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
 838
 839         if (!device || !acpi_driver_data(device))
 840                 return_VALUE(-EINVAL);
 841
 842         link = (struct acpi_pci_link *)acpi_driver_data(device);
 843
 844         mutex_lock(&acpi_link_lock);
 845         list_del(&link->node);
 846         mutex_unlock(&acpi_link_lock);
 847
 848         kfree(link);
 849
 850         return_VALUE(0);
 851 }
 852
 853 /*
 854  * modify acpi_irq_penalty[] from cmdline
 855  */
 856 static int __init acpi_irq_penalty_update(char *str, int used)
 857 {
 858         int i;
 859
 860         for (i = 0; i < 16; i++) {
 861                 int retval;
 862                 int irq;
 863
 864                 retval = get_option(&str, &irq);
 865
 866                 if (!retval)
 867                         break;  /* no number found */
 868
 869                 if (irq < 0)
 870                         continue;
 871
 872                 if (irq >= ACPI_MAX_IRQS)
 873                         continue;
 874
 875                 if (used)
 876                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 877                 else
 878                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 879
 880                 if (retval != 2)        /* no next number */
 881                         break;
 882         }
 883         return 1;
 884 }
 885
 886 /*
 887  * We'd like PNP to call this routine for the
 888  * single ISA_USED value for each legacy device.
 889  * But instead it calls us with each POSSIBLE setting.
 890  * There is no ISA_POSSIBLE weight, so we simply use
 891  * the (small) PCI_USING penalty.
 892  */
 893 void acpi_penalize_isa_irq(int irq, int active)
 894 {
 895         if (active)
 896                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 897         else
 898                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 899 }
 900
 901 /*
 902  * Over-ride default table to reserve additional IRQs for use by ISA
 903  * e.g. acpi_irq_isa=5
 904  * Useful for telling ACPI how not to interfere with your ISA sound card.
 905  */
 906 static int __init acpi_irq_isa(char *str)
 907 {
 908         return acpi_irq_penalty_update(str, 1);
 909 }
 910
 911 __setup("acpi_irq_isa=", acpi_irq_isa);
 912
 913 /*
 914  * Over-ride default table to free additional IRQs for use by PCI
 915  * e.g. acpi_irq_pci=7,15
 916  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 917  */
 918 static int __init acpi_irq_pci(char *str)
 919 {
 920         return acpi_irq_penalty_update(str, 0);
 921 }
 922
 923 __setup("acpi_irq_pci=", acpi_irq_pci);
 924
 925 static int __init acpi_irq_nobalance_set(char *str)
 926 {
 927         acpi_irq_balance = 0;
 928         return 1;
 929 }
 930
 931 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 932
 933 int __init acpi_irq_balance_set(char *str)
 934 {
 935         acpi_irq_balance = 1;
 936         return 1;
 937 }
 938
 939 __setup("acpi_irq_balance", acpi_irq_balance_set);
 940
 941 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 942 static struct sysdev_class irqrouter_sysdev_class = {
 943         set_kset_name("irqrouter"),
 944         .resume = irqrouter_resume,
 945 };
 946
 947 static struct sys_device device_irqrouter = {
 948         .id = 0,
 949         .cls = &irqrouter_sysdev_class,
 950 };
 951
 952 static int __init irqrouter_init_sysfs(void)
 953 {
 954         int error;
 955
 956         ACPI_FUNCTION_TRACE("irqrouter_init_sysfs");
 957
 958         if (acpi_disabled || acpi_noirq)
 959                 return_VALUE(0);
 960
 961         error = sysdev_class_register(&irqrouter_sysdev_class);
 962         if (!error)
 963                 error = sysdev_register(&device_irqrouter);
 964
 965         return_VALUE(error);
 966 }
 967
 968 device_initcall(irqrouter_init_sysfs);
 969
 970 static int __init acpi_pci_link_init(void)
 971 {
 972         ACPI_FUNCTION_TRACE("acpi_pci_link_init");
 973
 974         if (acpi_noirq)
 975                 return_VALUE(0);
 976
 977         acpi_link.count = 0;
 978         INIT_LIST_HEAD(&acpi_link.entries);
 979
 980         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 981                 return_VALUE(-ENODEV);
 982
 983         return_VALUE(0);
 984 }
 985
 986 subsys_initcall(acpi_pci_link_init);