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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  21  *
  22  * TBD:
  23  *      1. Support more than one IRQ resource entry per link device (index).
  24  *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  25  *         for IRQ management (e.g. start()->_SRS).
  26  */
  27
  28 #include <linux/syscore_ops.h>
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/types.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/pm.h>
  35 #include <linux/pci.h>
  36 #include <linux/mutex.h>
  37 #include <linux/slab.h>
  38 #include <linux/acpi.h>
  39
  40 #include "internal.h"
  41
  42 #define _COMPONENT                      ACPI_PCI_COMPONENT
  43 ACPI_MODULE_NAME("pci_link");
  44 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  45 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  46 #define ACPI_PCI_LINK_FILE_INFO         "info"
  47 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  48 #define ACPI_PCI_LINK_MAX_POSSIBLE      16
  49
  50 static int acpi_pci_link_add(struct acpi_device *device,
  51                              const struct acpi_device_id *not_used);
  52 static void acpi_pci_link_remove(struct acpi_device *device);
  53
  54 static const struct acpi_device_id link_device_ids[] = {
  55         {"PNP0C0F", 0},
  56         {"", 0},
  57 };
  58
  59 static struct acpi_scan_handler pci_link_handler = {
  60         .ids = link_device_ids,
  61         .attach = acpi_pci_link_add,
  62         .detach = acpi_pci_link_remove,
  63 };
  64
  65 /*
  66  * If a link is initialized, we never change its active and initialized
  67  * later even the link is disable. Instead, we just repick the active irq
  68  */
  69 struct acpi_pci_link_irq {
  70         u8 active;              /* Current IRQ */
  71         u8 triggering;          /* All IRQs */
  72         u8 polarity;            /* All IRQs */
  73         u8 resource_type;
  74         u8 possible_count;
  75         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  76         u8 initialized:1;
  77         u8 reserved:7;
  78 };
  79
  80 struct acpi_pci_link {
  81         struct list_head                list;
  82         struct acpi_device              *device;
  83         struct acpi_pci_link_irq        irq;
  84         int                             refcnt;
  85 };
  86
  87 static LIST_HEAD(acpi_link_list);
  88 static DEFINE_MUTEX(acpi_link_lock);
  89
  90 /* --------------------------------------------------------------------------
  91                             PCI Link Device Management
  92    -------------------------------------------------------------------------- */
  93
  94 /*
  95  * set context (link) possible list from resource list
  96  */
  97 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
  98                                                 void *context)
  99 {
 100         struct acpi_pci_link *link = context;
 101         u32 i;
 102
 103         switch (resource->type) {
 104         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 105         case ACPI_RESOURCE_TYPE_END_TAG:
 106                 return AE_OK;
 107         case ACPI_RESOURCE_TYPE_IRQ:
 108                 {
 109                         struct acpi_resource_irq *p = &resource->data.irq;
 110                         if (!p || !p->interrupt_count) {
 111                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 112                                                   "Blank _PRS IRQ resource\n"));
 113                                 return AE_OK;
 114                         }
 115                         for (i = 0;
 116                              (i < p->interrupt_count
 117                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 118                                 if (!p->interrupts[i]) {
 119                                         printk(KERN_WARNING PREFIX
 120                                                "Invalid _PRS IRQ %d\n",
 121                                                p->interrupts[i]);
 122                                         continue;
 123                                 }
 124                                 link->irq.possible[i] = p->interrupts[i];
 125                                 link->irq.possible_count++;
 126                         }
 127                         link->irq.triggering = p->triggering;
 128                         link->irq.polarity = p->polarity;
 129                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 130                         break;
 131                 }
 132         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 133                 {
 134                         struct acpi_resource_extended_irq *p =
 135                             &resource->data.extended_irq;
 136                         if (!p || !p->interrupt_count) {
 137                                 printk(KERN_WARNING PREFIX
 138                                               "Blank _PRS EXT IRQ resource\n");
 139                                 return AE_OK;
 140                         }
 141                         for (i = 0;
 142                              (i < p->interrupt_count
 143                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 144                                 if (!p->interrupts[i]) {
 145                                         printk(KERN_WARNING PREFIX
 146                                                "Invalid _PRS IRQ %d\n",
 147                                                p->interrupts[i]);
 148                                         continue;
 149                                 }
 150                                 link->irq.possible[i] = p->interrupts[i];
 151                                 link->irq.possible_count++;
 152                         }
 153                         link->irq.triggering = p->triggering;
 154                         link->irq.polarity = p->polarity;
 155                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 156                         break;
 157                 }
 158         default:
 159                 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 160                        resource->type);
 161                 return AE_OK;
 162         }
 163
 164         return AE_CTRL_TERMINATE;
 165 }
 166
 167 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 168 {
 169         acpi_status status;
 170
 171         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 172                                      acpi_pci_link_check_possible, link);
 173         if (ACPI_FAILURE(status)) {
 174                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 175                 return -ENODEV;
 176         }
 177
 178         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 179                           "Found %d possible IRQs\n",
 180                           link->irq.possible_count));
 181
 182         return 0;
 183 }
 184
 185 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 186                                                void *context)
 187 {
 188         int *irq = context;
 189
 190         switch (resource->type) {
 191         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 192         case ACPI_RESOURCE_TYPE_END_TAG:
 193                 return AE_OK;
 194         case ACPI_RESOURCE_TYPE_IRQ:
 195                 {
 196                         struct acpi_resource_irq *p = &resource->data.irq;
 197                         if (!p || !p->interrupt_count) {
 198                                 /*
 199                                  * IRQ descriptors may have no IRQ# bits set,
 200                                  * particularly those those w/ _STA disabled
 201                                  */
 202                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 203                                                   "Blank _CRS IRQ resource\n"));
 204                                 return AE_OK;
 205                         }
 206                         *irq = p->interrupts[0];
 207                         break;
 208                 }
 209         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 210                 {
 211                         struct acpi_resource_extended_irq *p =
 212                             &resource->data.extended_irq;
 213                         if (!p || !p->interrupt_count) {
 214                                 /*
 215                                  * extended IRQ descriptors must
 216                                  * return at least 1 IRQ
 217                                  */
 218                                 printk(KERN_WARNING PREFIX
 219                                               "Blank _CRS EXT IRQ resource\n");
 220                                 return AE_OK;
 221                         }
 222                         *irq = p->interrupts[0];
 223                         break;
 224                 }
 225                 break;
 226         default:
 227                 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 228                        resource->type);
 229                 return AE_OK;
 230         }
 231
 232         return AE_CTRL_TERMINATE;
 233 }
 234
 235 /*
 236  * Run _CRS and set link->irq.active
 237  *
 238  * return value:
 239  * 0 - success
 240  * !0 - failure
 241  */
 242 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 243 {
 244         int result = 0;
 245         acpi_status status;
 246         int irq = 0;
 247
 248         link->irq.active = 0;
 249
 250         /* in practice, status disabled is meaningless, ignore it */
 251         if (acpi_strict) {
 252                 /* Query _STA, set link->device->status */
 253                 result = acpi_bus_get_status(link->device);
 254                 if (result) {
 255                         printk(KERN_ERR PREFIX "Unable to read status\n");
 256                         goto end;
 257                 }
 258
 259                 if (!link->device->status.enabled) {
 260                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 261                         return 0;
 262                 }
 263         }
 264
 265         /*
 266          * Query and parse _CRS to get the current IRQ assignment.
 267          */
 268
 269         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 270                                      acpi_pci_link_check_current, &irq);
 271         if (ACPI_FAILURE(status)) {
 272                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 273                 result = -ENODEV;
 274                 goto end;
 275         }
 276
 277         if (acpi_strict && !irq) {
 278                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 279                 result = -ENODEV;
 280         }
 281
 282         link->irq.active = irq;
 283
 284         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 285
 286       end:
 287         return result;
 288 }
 289
 290 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 291 {
 292         int result;
 293         acpi_status status;
 294         struct {
 295                 struct acpi_resource res;
 296                 struct acpi_resource end;
 297         } *resource;
 298         struct acpi_buffer buffer = { 0, NULL };
 299
 300         if (!irq)
 301                 return -EINVAL;
 302
 303         resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 304         if (!resource)
 305                 return -ENOMEM;
 306
 307         buffer.length = sizeof(*resource) + 1;
 308         buffer.pointer = resource;
 309
 310         switch (link->irq.resource_type) {
 311         case ACPI_RESOURCE_TYPE_IRQ:
 312                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 313                 resource->res.length = sizeof(struct acpi_resource);
 314                 resource->res.data.irq.triggering = link->irq.triggering;
 315                 resource->res.data.irq.polarity =
 316                     link->irq.polarity;
 317                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 318                         resource->res.data.irq.sharable =
 319                             ACPI_EXCLUSIVE;
 320                 else
 321                         resource->res.data.irq.sharable = ACPI_SHARED;
 322                 resource->res.data.irq.interrupt_count = 1;
 323                 resource->res.data.irq.interrupts[0] = irq;
 324                 break;
 325
 326         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 327                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 328                 resource->res.length = sizeof(struct acpi_resource);
 329                 resource->res.data.extended_irq.producer_consumer =
 330                     ACPI_CONSUMER;
 331                 resource->res.data.extended_irq.triggering =
 332                     link->irq.triggering;
 333                 resource->res.data.extended_irq.polarity =
 334                     link->irq.polarity;
 335                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 336                         resource->res.data.irq.sharable =
 337                             ACPI_EXCLUSIVE;
 338                 else
 339                         resource->res.data.irq.sharable = ACPI_SHARED;
 340                 resource->res.data.extended_irq.interrupt_count = 1;
 341                 resource->res.data.extended_irq.interrupts[0] = irq;
 342                 /* ignore resource_source, it's optional */
 343                 break;
 344         default:
 345                 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 346                 result = -EINVAL;
 347                 goto end;
 348
 349         }
 350         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 351         resource->end.length = sizeof(struct acpi_resource);
 352
 353         /* Attempt to set the resource */
 354         status = acpi_set_current_resources(link->device->handle, &buffer);
 355
 356         /* check for total failure */
 357         if (ACPI_FAILURE(status)) {
 358                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 359                 result = -ENODEV;
 360                 goto end;
 361         }
 362
 363         /* Query _STA, set device->status */
 364         result = acpi_bus_get_status(link->device);
 365         if (result) {
 366                 printk(KERN_ERR PREFIX "Unable to read status\n");
 367                 goto end;
 368         }
 369         if (!link->device->status.enabled) {
 370                 printk(KERN_WARNING PREFIX
 371                               "%s [%s] disabled and referenced, BIOS bug\n",
 372                               acpi_device_name(link->device),
 373                               acpi_device_bid(link->device));
 374         }
 375
 376         /* Query _CRS, set link->irq.active */
 377         result = acpi_pci_link_get_current(link);
 378         if (result) {
 379                 goto end;
 380         }
 381
 382         /*
 383          * Is current setting not what we set?
 384          * set link->irq.active
 385          */
 386         if (link->irq.active != irq) {
 387                 /*
 388                  * policy: when _CRS doesn't return what we just _SRS
 389                  * assume _SRS worked and override _CRS value.
 390                  */
 391                 printk(KERN_WARNING PREFIX
 392                               "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 393                               acpi_device_name(link->device),
 394                               acpi_device_bid(link->device), link->irq.active, irq);
 395                 link->irq.active = irq;
 396         }
 397
 398         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 399
 400       end:
 401         kfree(resource);
 402         return result;
 403 }
 404
 405 /* --------------------------------------------------------------------------
 406                             PCI Link IRQ Management
 407    -------------------------------------------------------------------------- */
 408
 409 /*
 410  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 411  * Link Devices to move the PIRQs around to minimize sharing.
 412  *
 413  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 414  * that the BIOS has already set to active.  This is necessary because
 415  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 416  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 417  * even if acpi_irq_nobalance is set.
 418  *
 419  * A tables of penalties avoids directing PCI interrupts to well known
 420  * ISA IRQs. Boot params are available to over-ride the default table:
 421  *
 422  * List interrupts that are free for PCI use.
 423  * acpi_irq_pci=n[,m]
 424  *
 425  * List interrupts that should not be used for PCI:
 426  * acpi_irq_isa=n[,m]
 427  *
 428  * Note that PCI IRQ routers have a list of possible IRQs,
 429  * which may not include the IRQs this table says are available.
 430  *
 431  * Since this heuristic can't tell the difference between a link
 432  * that no device will attach to, vs. a link which may be shared
 433  * by multiple active devices -- it is not optimal.
 434  *
 435  * If interrupt performance is that important, get an IO-APIC system
 436  * with a pin dedicated to each device.  Or for that matter, an MSI
 437  * enabled system.
 438  */
 439
 440 #define ACPI_MAX_IRQS           256
 441 #define ACPI_MAX_ISA_IRQ        16
 442
 443 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 444 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 445 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 446 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 447 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 448 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 449
 450 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 451         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 452         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 453         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 454         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 455         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 456         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 457         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 458         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 459         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 460         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 461         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 462         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 463         PIRQ_PENALTY_ISA_USED,          /* IRQ12 mouse */
 464         PIRQ_PENALTY_ISA_USED,          /* IRQ13 fpe, sometimes */
 465         PIRQ_PENALTY_ISA_USED,          /* IRQ14 ide0 */
 466         PIRQ_PENALTY_ISA_USED,          /* IRQ15 ide1 */
 467         /* >IRQ15 */
 468 };
 469
 470 int __init acpi_irq_penalty_init(void)
 471 {
 472         struct acpi_pci_link *link;
 473         int i;
 474
 475         /*
 476          * Update penalties to facilitate IRQ balancing.
 477          */
 478         list_for_each_entry(link, &acpi_link_list, list) {
 479
 480                 /*
 481                  * reflect the possible and active irqs in the penalty table --
 482                  * useful for breaking ties.
 483                  */
 484                 if (link->irq.possible_count) {
 485                         int penalty =
 486                             PIRQ_PENALTY_PCI_POSSIBLE /
 487                             link->irq.possible_count;
 488
 489                         for (i = 0; i < link->irq.possible_count; i++) {
 490                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 491                                         acpi_irq_penalty[link->irq.
 492                                                          possible[i]] +=
 493                                             penalty;
 494                         }
 495
 496                 } else if (link->irq.active) {
 497                         acpi_irq_penalty[link->irq.active] +=
 498                             PIRQ_PENALTY_PCI_POSSIBLE;
 499                 }
 500         }
 501
 502         return 0;
 503 }
 504
 505 static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 506
 507 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 508 {
 509         int irq;
 510         int i;
 511
 512         if (link->irq.initialized) {
 513                 if (link->refcnt == 0)
 514                         /* This means the link is disabled but initialized */
 515                         acpi_pci_link_set(link, link->irq.active);
 516                 return 0;
 517         }
 518
 519         /*
 520          * search for active IRQ in list of possible IRQs.
 521          */
 522         for (i = 0; i < link->irq.possible_count; ++i) {
 523                 if (link->irq.active == link->irq.possible[i])
 524                         break;
 525         }
 526         /*
 527          * forget active IRQ that is not in possible list
 528          */
 529         if (i == link->irq.possible_count) {
 530                 if (acpi_strict)
 531                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 532                                       " in _PRS\n", link->irq.active);
 533                 link->irq.active = 0;
 534         }
 535
 536         /*
 537          * if active found, use it; else pick entry from end of possible list.
 538          */
 539         if (link->irq.active)
 540                 irq = link->irq.active;
 541         else
 542                 irq = link->irq.possible[link->irq.possible_count - 1];
 543
 544         if (acpi_irq_balance || !link->irq.active) {
 545                 /*
 546                  * Select the best IRQ.  This is done in reverse to promote
 547                  * the use of IRQs 9, 10, 11, and >15.
 548                  */
 549                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 550                         if (acpi_irq_penalty[irq] >
 551                             acpi_irq_penalty[link->irq.possible[i]])
 552                                 irq = link->irq.possible[i];
 553                 }
 554         }
 555         if (acpi_irq_penalty[irq] >= PIRQ_PENALTY_ISA_ALWAYS) {
 556                 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
 557                             "Try pci=noacpi or acpi=off\n",
 558                             acpi_device_name(link->device),
 559                             acpi_device_bid(link->device));
 560                 return -ENODEV;
 561         }
 562
 563         /* Attempt to enable the link device at this IRQ. */
 564         if (acpi_pci_link_set(link, irq)) {
 565                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 566                             "Try pci=noacpi or acpi=off\n",
 567                             acpi_device_name(link->device),
 568                             acpi_device_bid(link->device));
 569                 return -ENODEV;
 570         } else {
 571                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 572                 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
 573                        acpi_device_name(link->device),
 574                        acpi_device_bid(link->device), link->irq.active);
 575         }
 576
 577         link->irq.initialized = 1;
 578         return 0;
 579 }
 580
 581 /*
 582  * acpi_pci_link_allocate_irq
 583  * success: return IRQ >= 0
 584  * failure: return -1
 585  */
 586 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 587                                int *polarity, char **name)
 588 {
 589         int result;
 590         struct acpi_device *device;
 591         struct acpi_pci_link *link;
 592
 593         result = acpi_bus_get_device(handle, &device);
 594         if (result) {
 595                 printk(KERN_ERR PREFIX "Invalid link device\n");
 596                 return -1;
 597         }
 598
 599         link = acpi_driver_data(device);
 600         if (!link) {
 601                 printk(KERN_ERR PREFIX "Invalid link context\n");
 602                 return -1;
 603         }
 604
 605         /* TBD: Support multiple index (IRQ) entries per Link Device */
 606         if (index) {
 607                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 608                 return -1;
 609         }
 610
 611         mutex_lock(&acpi_link_lock);
 612         if (acpi_pci_link_allocate(link)) {
 613                 mutex_unlock(&acpi_link_lock);
 614                 return -1;
 615         }
 616
 617         if (!link->irq.active) {
 618                 mutex_unlock(&acpi_link_lock);
 619                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 620                 return -1;
 621         }
 622         link->refcnt++;
 623         mutex_unlock(&acpi_link_lock);
 624
 625         if (triggering)
 626                 *triggering = link->irq.triggering;
 627         if (polarity)
 628                 *polarity = link->irq.polarity;
 629         if (name)
 630                 *name = acpi_device_bid(link->device);
 631         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 632                           "Link %s is referenced\n",
 633                           acpi_device_bid(link->device)));
 634         return (link->irq.active);
 635 }
 636
 637 /*
 638  * We don't change link's irq information here.  After it is reenabled, we
 639  * continue use the info
 640  */
 641 int acpi_pci_link_free_irq(acpi_handle handle)
 642 {
 643         struct acpi_device *device;
 644         struct acpi_pci_link *link;
 645         acpi_status result;
 646
 647         result = acpi_bus_get_device(handle, &device);
 648         if (result) {
 649                 printk(KERN_ERR PREFIX "Invalid link device\n");
 650                 return -1;
 651         }
 652
 653         link = acpi_driver_data(device);
 654         if (!link) {
 655                 printk(KERN_ERR PREFIX "Invalid link context\n");
 656                 return -1;
 657         }
 658
 659         mutex_lock(&acpi_link_lock);
 660         if (!link->irq.initialized) {
 661                 mutex_unlock(&acpi_link_lock);
 662                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 663                 return -1;
 664         }
 665 #ifdef  FUTURE_USE
 666         /*
 667          * The Link reference count allows us to _DISable an unused link
 668          * and suspend time, and set it again  on resume.
 669          * However, 2.6.12 still has irq_router.resume
 670          * which blindly restores the link state.
 671          * So we disable the reference count method
 672          * to prevent duplicate acpi_pci_link_set()
 673          * which would harm some systems
 674          */
 675         link->refcnt--;
 676 #endif
 677         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 678                           "Link %s is dereferenced\n",
 679                           acpi_device_bid(link->device)));
 680
 681         if (link->refcnt == 0)
 682                 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 683
 684         mutex_unlock(&acpi_link_lock);
 685         return (link->irq.active);
 686 }
 687
 688 /* --------------------------------------------------------------------------
 689                                  Driver Interface
 690    -------------------------------------------------------------------------- */
 691
 692 static int acpi_pci_link_add(struct acpi_device *device,
 693                              const struct acpi_device_id *not_used)
 694 {
 695         int result;
 696         struct acpi_pci_link *link;
 697         int i;
 698         int found = 0;
 699
 700         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 701         if (!link)
 702                 return -ENOMEM;
 703
 704         link->device = device;
 705         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 706         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 707         device->driver_data = link;
 708
 709         mutex_lock(&acpi_link_lock);
 710         result = acpi_pci_link_get_possible(link);
 711         if (result)
 712                 goto end;
 713
 714         /* query and set link->irq.active */
 715         acpi_pci_link_get_current(link);
 716
 717         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 718                acpi_device_bid(device));
 719         for (i = 0; i < link->irq.possible_count; i++) {
 720                 if (link->irq.active == link->irq.possible[i]) {
 721                         printk(KERN_CONT " *%d", link->irq.possible[i]);
 722                         found = 1;
 723                 } else
 724                         printk(KERN_CONT " %d", link->irq.possible[i]);
 725         }
 726
 727         printk(KERN_CONT ")");
 728
 729         if (!found)
 730                 printk(KERN_CONT " *%d", link->irq.active);
 731
 732         if (!link->device->status.enabled)
 733                 printk(KERN_CONT ", disabled.");
 734
 735         printk(KERN_CONT "\n");
 736
 737         list_add_tail(&link->list, &acpi_link_list);
 738
 739       end:
 740         /* disable all links -- to be activated on use */
 741         acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 742         mutex_unlock(&acpi_link_lock);
 743
 744         if (result)
 745                 kfree(link);
 746
 747         return result < 0 ? result : 1;
 748 }
 749
 750 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 751 {
 752         if (link->refcnt && link->irq.active && link->irq.initialized)
 753                 return (acpi_pci_link_set(link, link->irq.active));
 754
 755         return 0;
 756 }
 757
 758 static void irqrouter_resume(void)
 759 {
 760         struct acpi_pci_link *link;
 761
 762         list_for_each_entry(link, &acpi_link_list, list) {
 763                 acpi_pci_link_resume(link);
 764         }
 765 }
 766
 767 static void acpi_pci_link_remove(struct acpi_device *device)
 768 {
 769         struct acpi_pci_link *link;
 770
 771         link = acpi_driver_data(device);
 772
 773         mutex_lock(&acpi_link_lock);
 774         list_del(&link->list);
 775         mutex_unlock(&acpi_link_lock);
 776
 777         kfree(link);
 778 }
 779
 780 /*
 781  * modify acpi_irq_penalty[] from cmdline
 782  */
 783 static int __init acpi_irq_penalty_update(char *str, int used)
 784 {
 785         int i;
 786
 787         for (i = 0; i < 16; i++) {
 788                 int retval;
 789                 int irq;
 790
 791                 retval = get_option(&str, &irq);
 792
 793                 if (!retval)
 794                         break;  /* no number found */
 795
 796                 if (irq < 0)
 797                         continue;
 798
 799                 if (irq >= ARRAY_SIZE(acpi_irq_penalty))
 800                         continue;
 801
 802                 if (used)
 803                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 804                 else
 805                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 806
 807                 if (retval != 2)        /* no next number */
 808                         break;
 809         }
 810         return 1;
 811 }
 812
 813 /*
 814  * We'd like PNP to call this routine for the
 815  * single ISA_USED value for each legacy device.
 816  * But instead it calls us with each POSSIBLE setting.
 817  * There is no ISA_POSSIBLE weight, so we simply use
 818  * the (small) PCI_USING penalty.
 819  */
 820 void acpi_penalize_isa_irq(int irq, int active)
 821 {
 822         if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 823                 if (active)
 824                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 825                 else
 826                         acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 827         }
 828 }
 829
 830 bool acpi_isa_irq_available(int irq)
 831 {
 832         return irq >= 0 && (irq >= ARRAY_SIZE(acpi_irq_penalty) ||
 833                             acpi_irq_penalty[irq] < PIRQ_PENALTY_ISA_ALWAYS);
 834 }
 835
 836 /*
 837  * Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict with
 838  * PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be use for
 839  * PCI IRQs.
 840  */
 841 void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 842 {
 843         if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
 844                 if (trigger != ACPI_MADT_TRIGGER_LEVEL ||
 845                     polarity != ACPI_MADT_POLARITY_ACTIVE_LOW)
 846                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_ALWAYS;
 847                 else
 848                         acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 849         }
 850 }
 851
 852 /*
 853  * Over-ride default table to reserve additional IRQs for use by ISA
 854  * e.g. acpi_irq_isa=5
 855  * Useful for telling ACPI how not to interfere with your ISA sound card.
 856  */
 857 static int __init acpi_irq_isa(char *str)
 858 {
 859         return acpi_irq_penalty_update(str, 1);
 860 }
 861
 862 __setup("acpi_irq_isa=", acpi_irq_isa);
 863
 864 /*
 865  * Over-ride default table to free additional IRQs for use by PCI
 866  * e.g. acpi_irq_pci=7,15
 867  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 868  */
 869 static int __init acpi_irq_pci(char *str)
 870 {
 871         return acpi_irq_penalty_update(str, 0);
 872 }
 873
 874 __setup("acpi_irq_pci=", acpi_irq_pci);
 875
 876 static int __init acpi_irq_nobalance_set(char *str)
 877 {
 878         acpi_irq_balance = 0;
 879         return 1;
 880 }
 881
 882 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 883
 884 static int __init acpi_irq_balance_set(char *str)
 885 {
 886         acpi_irq_balance = 1;
 887         return 1;
 888 }
 889
 890 __setup("acpi_irq_balance", acpi_irq_balance_set);
 891
 892 static struct syscore_ops irqrouter_syscore_ops = {
 893         .resume = irqrouter_resume,
 894 };
 895
 896 void __init acpi_pci_link_init(void)
 897 {
 898         if (acpi_noirq)
 899                 return;
 900
 901         if (acpi_irq_balance == -1) {
 902                 /* no command line switch: enable balancing in IOAPIC mode */
 903                 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 904                         acpi_irq_balance = 1;
 905                 else
 906                         acpi_irq_balance = 0;
 907         }
 908         register_syscore_ops(&irqrouter_syscore_ops);
 909         acpi_scan_add_handler(&pci_link_handler);
 910 }