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 #include <linux/irq.h>
  40
  41 #include "internal.h"
  42
  43 #define _COMPONENT                      ACPI_PCI_COMPONENT
  44 ACPI_MODULE_NAME("pci_link");
  45 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  46 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  47 #define ACPI_PCI_LINK_FILE_INFO         "info"
  48 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  49 #define ACPI_PCI_LINK_MAX_POSSIBLE      16
  50
  51 static int acpi_pci_link_add(struct acpi_device *device,
  52                              const struct acpi_device_id *not_used);
  53 static void acpi_pci_link_remove(struct acpi_device *device);
  54
  55 static const struct acpi_device_id link_device_ids[] = {
  56         {"PNP0C0F", 0},
  57         {"", 0},
  58 };
  59
  60 static struct acpi_scan_handler pci_link_handler = {
  61         .ids = link_device_ids,
  62         .attach = acpi_pci_link_add,
  63         .detach = acpi_pci_link_remove,
  64 };
  65
  66 /*
  67  * If a link is initialized, we never change its active and initialized
  68  * later even the link is disable. Instead, we just repick the active irq
  69  */
  70 struct acpi_pci_link_irq {
  71         u32 active;             /* Current IRQ */
  72         u8 triggering;          /* All IRQs */
  73         u8 polarity;            /* All IRQs */
  74         u8 resource_type;
  75         u8 possible_count;
  76         u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  77         u8 initialized:1;
  78         u8 reserved:7;
  79 };
  80
  81 struct acpi_pci_link {
  82         struct list_head                list;
  83         struct acpi_device              *device;
  84         struct acpi_pci_link_irq        irq;
  85         int                             refcnt;
  86 };
  87
  88 static LIST_HEAD(acpi_link_list);
  89 static DEFINE_MUTEX(acpi_link_lock);
  90 static int sci_irq = -1, sci_penalty;
  91
  92 /* --------------------------------------------------------------------------
  93                             PCI Link Device Management
  94    -------------------------------------------------------------------------- */
  95
  96 /*
  97  * set context (link) possible list from resource list
  98  */
  99 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
 100                                                 void *context)
 101 {
 102         struct acpi_pci_link *link = context;
 103         u32 i;
 104
 105         switch (resource->type) {
 106         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 107         case ACPI_RESOURCE_TYPE_END_TAG:
 108                 return AE_OK;
 109         case ACPI_RESOURCE_TYPE_IRQ:
 110                 {
 111                         struct acpi_resource_irq *p = &resource->data.irq;
 112                         if (!p || !p->interrupt_count) {
 113                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 114                                                   "Blank _PRS IRQ resource\n"));
 115                                 return AE_OK;
 116                         }
 117                         for (i = 0;
 118                              (i < p->interrupt_count
 119                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 120                                 if (!p->interrupts[i]) {
 121                                         printk(KERN_WARNING PREFIX
 122                                                "Invalid _PRS IRQ %d\n",
 123                                                p->interrupts[i]);
 124                                         continue;
 125                                 }
 126                                 link->irq.possible[i] = p->interrupts[i];
 127                                 link->irq.possible_count++;
 128                         }
 129                         link->irq.triggering = p->triggering;
 130                         link->irq.polarity = p->polarity;
 131                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 132                         break;
 133                 }
 134         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 135                 {
 136                         struct acpi_resource_extended_irq *p =
 137                             &resource->data.extended_irq;
 138                         if (!p || !p->interrupt_count) {
 139                                 printk(KERN_WARNING PREFIX
 140                                               "Blank _PRS EXT IRQ resource\n");
 141                                 return AE_OK;
 142                         }
 143                         for (i = 0;
 144                              (i < p->interrupt_count
 145                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 146                                 if (!p->interrupts[i]) {
 147                                         printk(KERN_WARNING PREFIX
 148                                                "Invalid _PRS IRQ %d\n",
 149                                                p->interrupts[i]);
 150                                         continue;
 151                                 }
 152                                 link->irq.possible[i] = p->interrupts[i];
 153                                 link->irq.possible_count++;
 154                         }
 155                         link->irq.triggering = p->triggering;
 156                         link->irq.polarity = p->polarity;
 157                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 158                         break;
 159                 }
 160         default:
 161                 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 162                        resource->type);
 163                 return AE_OK;
 164         }
 165
 166         return AE_CTRL_TERMINATE;
 167 }
 168
 169 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 170 {
 171         acpi_status status;
 172
 173         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 174                                      acpi_pci_link_check_possible, link);
 175         if (ACPI_FAILURE(status)) {
 176                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 177                 return -ENODEV;
 178         }
 179
 180         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 181                           "Found %d possible IRQs\n",
 182                           link->irq.possible_count));
 183
 184         return 0;
 185 }
 186
 187 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 188                                                void *context)
 189 {
 190         int *irq = context;
 191
 192         switch (resource->type) {
 193         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 194         case ACPI_RESOURCE_TYPE_END_TAG:
 195                 return AE_OK;
 196         case ACPI_RESOURCE_TYPE_IRQ:
 197                 {
 198                         struct acpi_resource_irq *p = &resource->data.irq;
 199                         if (!p || !p->interrupt_count) {
 200                                 /*
 201                                  * IRQ descriptors may have no IRQ# bits set,
 202                                  * particularly those those w/ _STA disabled
 203                                  */
 204                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 205                                                   "Blank _CRS IRQ resource\n"));
 206                                 return AE_OK;
 207                         }
 208                         *irq = p->interrupts[0];
 209                         break;
 210                 }
 211         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 212                 {
 213                         struct acpi_resource_extended_irq *p =
 214                             &resource->data.extended_irq;
 215                         if (!p || !p->interrupt_count) {
 216                                 /*
 217                                  * extended IRQ descriptors must
 218                                  * return at least 1 IRQ
 219                                  */
 220                                 printk(KERN_WARNING PREFIX
 221                                               "Blank _CRS EXT IRQ resource\n");
 222                                 return AE_OK;
 223                         }
 224                         *irq = p->interrupts[0];
 225                         break;
 226                 }
 227                 break;
 228         default:
 229                 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 230                        resource->type);
 231                 return AE_OK;
 232         }
 233
 234         return AE_CTRL_TERMINATE;
 235 }
 236
 237 /*
 238  * Run _CRS and set link->irq.active
 239  *
 240  * return value:
 241  * 0 - success
 242  * !0 - failure
 243  */
 244 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 245 {
 246         int result = 0;
 247         acpi_status status;
 248         int irq = 0;
 249
 250         link->irq.active = 0;
 251
 252         /* in practice, status disabled is meaningless, ignore it */
 253         if (acpi_strict) {
 254                 /* Query _STA, set link->device->status */
 255                 result = acpi_bus_get_status(link->device);
 256                 if (result) {
 257                         printk(KERN_ERR PREFIX "Unable to read status\n");
 258                         goto end;
 259                 }
 260
 261                 if (!link->device->status.enabled) {
 262                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 263                         return 0;
 264                 }
 265         }
 266
 267         /*
 268          * Query and parse _CRS to get the current IRQ assignment.
 269          */
 270
 271         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 272                                      acpi_pci_link_check_current, &irq);
 273         if (ACPI_FAILURE(status)) {
 274                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 275                 result = -ENODEV;
 276                 goto end;
 277         }
 278
 279         if (acpi_strict && !irq) {
 280                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 281                 result = -ENODEV;
 282         }
 283
 284         link->irq.active = irq;
 285
 286         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 287
 288       end:
 289         return result;
 290 }
 291
 292 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 293 {
 294         int result;
 295         acpi_status status;
 296         struct {
 297                 struct acpi_resource res;
 298                 struct acpi_resource end;
 299         } *resource;
 300         struct acpi_buffer buffer = { 0, NULL };
 301
 302         if (!irq)
 303                 return -EINVAL;
 304
 305         resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 306         if (!resource)
 307                 return -ENOMEM;
 308
 309         buffer.length = sizeof(*resource) + 1;
 310         buffer.pointer = resource;
 311
 312         switch (link->irq.resource_type) {
 313         case ACPI_RESOURCE_TYPE_IRQ:
 314                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 315                 resource->res.length = sizeof(struct acpi_resource);
 316                 resource->res.data.irq.triggering = link->irq.triggering;
 317                 resource->res.data.irq.polarity =
 318                     link->irq.polarity;
 319                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 320                         resource->res.data.irq.sharable =
 321                             ACPI_EXCLUSIVE;
 322                 else
 323                         resource->res.data.irq.sharable = ACPI_SHARED;
 324                 resource->res.data.irq.interrupt_count = 1;
 325                 resource->res.data.irq.interrupts[0] = irq;
 326                 break;
 327
 328         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 329                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 330                 resource->res.length = sizeof(struct acpi_resource);
 331                 resource->res.data.extended_irq.producer_consumer =
 332                     ACPI_CONSUMER;
 333                 resource->res.data.extended_irq.triggering =
 334                     link->irq.triggering;
 335                 resource->res.data.extended_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.extended_irq.interrupt_count = 1;
 343                 resource->res.data.extended_irq.interrupts[0] = irq;
 344                 /* ignore resource_source, it's optional */
 345                 break;
 346         default:
 347                 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 348                 result = -EINVAL;
 349                 goto end;
 350
 351         }
 352         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 353         resource->end.length = sizeof(struct acpi_resource);
 354
 355         /* Attempt to set the resource */
 356         status = acpi_set_current_resources(link->device->handle, &buffer);
 357
 358         /* check for total failure */
 359         if (ACPI_FAILURE(status)) {
 360                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 361                 result = -ENODEV;
 362                 goto end;
 363         }
 364
 365         /* Query _STA, set device->status */
 366         result = acpi_bus_get_status(link->device);
 367         if (result) {
 368                 printk(KERN_ERR PREFIX "Unable to read status\n");
 369                 goto end;
 370         }
 371         if (!link->device->status.enabled) {
 372                 printk(KERN_WARNING PREFIX
 373                               "%s [%s] disabled and referenced, BIOS bug\n",
 374                               acpi_device_name(link->device),
 375                               acpi_device_bid(link->device));
 376         }
 377
 378         /* Query _CRS, set link->irq.active */
 379         result = acpi_pci_link_get_current(link);
 380         if (result) {
 381                 goto end;
 382         }
 383
 384         /*
 385          * Is current setting not what we set?
 386          * set link->irq.active
 387          */
 388         if (link->irq.active != irq) {
 389                 /*
 390                  * policy: when _CRS doesn't return what we just _SRS
 391                  * assume _SRS worked and override _CRS value.
 392                  */
 393                 printk(KERN_WARNING PREFIX
 394                               "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 395                               acpi_device_name(link->device),
 396                               acpi_device_bid(link->device), link->irq.active, irq);
 397                 link->irq.active = irq;
 398         }
 399
 400         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 401
 402       end:
 403         kfree(resource);
 404         return result;
 405 }
 406
 407 /* --------------------------------------------------------------------------
 408                             PCI Link IRQ Management
 409    -------------------------------------------------------------------------- */
 410
 411 /*
 412  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 413  * Link Devices to move the PIRQs around to minimize sharing.
 414  *
 415  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 416  * that the BIOS has already set to active.  This is necessary because
 417  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 418  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 419  * even if acpi_irq_nobalance is set.
 420  *
 421  * A tables of penalties avoids directing PCI interrupts to well known
 422  * ISA IRQs. Boot params are available to over-ride the default table:
 423  *
 424  * List interrupts that are free for PCI use.
 425  * acpi_irq_pci=n[,m]
 426  *
 427  * List interrupts that should not be used for PCI:
 428  * acpi_irq_isa=n[,m]
 429  *
 430  * Note that PCI IRQ routers have a list of possible IRQs,
 431  * which may not include the IRQs this table says are available.
 432  *
 433  * Since this heuristic can't tell the difference between a link
 434  * that no device will attach to, vs. a link which may be shared
 435  * by multiple active devices -- it is not optimal.
 436  *
 437  * If interrupt performance is that important, get an IO-APIC system
 438  * with a pin dedicated to each device.  Or for that matter, an MSI
 439  * enabled system.
 440  */
 441
 442 #define ACPI_MAX_ISA_IRQS       16
 443
 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_isa_irq_penalty[ACPI_MAX_ISA_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         0,                              /* IRQ9  PCI, often acpi */
 461         0,                              /* IRQ10 PCI */
 462         0,                              /* 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 static int acpi_irq_pci_sharing_penalty(int irq)
 471 {
 472         struct acpi_pci_link *link;
 473         int penalty = 0;
 474         int i;
 475
 476         list_for_each_entry(link, &acpi_link_list, list) {
 477                 /*
 478                  * If a link is active, penalize its IRQ heavily
 479                  * so we try to choose a different IRQ.
 480                  */
 481                 if (link->irq.active && link->irq.active == irq)
 482                         penalty += PIRQ_PENALTY_PCI_USING;
 483
 484                 /*
 485                  * penalize the IRQs PCI might use, but not as severely.
 486                  */
 487                 for (i = 0; i < link->irq.possible_count; i++)
 488                         if (link->irq.possible[i] == irq)
 489                                 penalty += PIRQ_PENALTY_PCI_POSSIBLE /
 490                                         link->irq.possible_count;
 491         }
 492
 493         return penalty;
 494 }
 495
 496 static int acpi_irq_get_penalty(int irq)
 497 {
 498         int penalty = 0;
 499
 500         if (irq == sci_irq)
 501                 penalty += sci_penalty;
 502
 503         if (irq < ACPI_MAX_ISA_IRQS)
 504                 return penalty + acpi_isa_irq_penalty[irq];
 505
 506         return penalty + acpi_irq_pci_sharing_penalty(irq);
 507 }
 508
 509 int __init acpi_irq_penalty_init(void)
 510 {
 511         struct acpi_pci_link *link;
 512         int i;
 513
 514         /*
 515          * Update penalties to facilitate IRQ balancing.
 516          */
 517         list_for_each_entry(link, &acpi_link_list, list) {
 518
 519                 /*
 520                  * reflect the possible and active irqs in the penalty table --
 521                  * useful for breaking ties.
 522                  */
 523                 if (link->irq.possible_count) {
 524                         int penalty =
 525                             PIRQ_PENALTY_PCI_POSSIBLE /
 526                             link->irq.possible_count;
 527
 528                         for (i = 0; i < link->irq.possible_count; i++) {
 529                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
 530                                         acpi_isa_irq_penalty[link->irq.
 531                                                          possible[i]] +=
 532                                             penalty;
 533                         }
 534
 535                 } else if (link->irq.active &&
 536                                 (link->irq.active < ACPI_MAX_ISA_IRQS)) {
 537                         acpi_isa_irq_penalty[link->irq.active] +=
 538                             PIRQ_PENALTY_PCI_POSSIBLE;
 539                 }
 540         }
 541
 542         return 0;
 543 }
 544
 545 static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 546
 547 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 548 {
 549         int irq;
 550         int i;
 551
 552         if (link->irq.initialized) {
 553                 if (link->refcnt == 0)
 554                         /* This means the link is disabled but initialized */
 555                         acpi_pci_link_set(link, link->irq.active);
 556                 return 0;
 557         }
 558
 559         /*
 560          * search for active IRQ in list of possible IRQs.
 561          */
 562         for (i = 0; i < link->irq.possible_count; ++i) {
 563                 if (link->irq.active == link->irq.possible[i])
 564                         break;
 565         }
 566         /*
 567          * forget active IRQ that is not in possible list
 568          */
 569         if (i == link->irq.possible_count) {
 570                 if (acpi_strict)
 571                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 572                                       " in _PRS\n", link->irq.active);
 573                 link->irq.active = 0;
 574         }
 575
 576         /*
 577          * if active found, use it; else pick entry from end of possible list.
 578          */
 579         if (link->irq.active)
 580                 irq = link->irq.active;
 581         else
 582                 irq = link->irq.possible[link->irq.possible_count - 1];
 583
 584         if (acpi_irq_balance || !link->irq.active) {
 585                 /*
 586                  * Select the best IRQ.  This is done in reverse to promote
 587                  * the use of IRQs 9, 10, 11, and >15.
 588                  */
 589                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 590                         if (acpi_irq_get_penalty(irq) >
 591                             acpi_irq_get_penalty(link->irq.possible[i]))
 592                                 irq = link->irq.possible[i];
 593                 }
 594         }
 595         if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
 596                 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
 597                             "Try pci=noacpi or acpi=off\n",
 598                             acpi_device_name(link->device),
 599                             acpi_device_bid(link->device));
 600                 return -ENODEV;
 601         }
 602
 603         /* Attempt to enable the link device at this IRQ. */
 604         if (acpi_pci_link_set(link, irq)) {
 605                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 606                             "Try pci=noacpi or acpi=off\n",
 607                             acpi_device_name(link->device),
 608                             acpi_device_bid(link->device));
 609                 return -ENODEV;
 610         } else {
 611                 if (link->irq.active < ACPI_MAX_ISA_IRQS)
 612                         acpi_isa_irq_penalty[link->irq.active] +=
 613                                 PIRQ_PENALTY_PCI_USING;
 614
 615                 printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
 616                        acpi_device_name(link->device),
 617                        acpi_device_bid(link->device), link->irq.active);
 618         }
 619
 620         link->irq.initialized = 1;
 621         return 0;
 622 }
 623
 624 /*
 625  * acpi_pci_link_allocate_irq
 626  * success: return IRQ >= 0
 627  * failure: return -1
 628  */
 629 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 630                                int *polarity, char **name)
 631 {
 632         int result;
 633         struct acpi_device *device;
 634         struct acpi_pci_link *link;
 635
 636         result = acpi_bus_get_device(handle, &device);
 637         if (result) {
 638                 printk(KERN_ERR PREFIX "Invalid link device\n");
 639                 return -1;
 640         }
 641
 642         link = acpi_driver_data(device);
 643         if (!link) {
 644                 printk(KERN_ERR PREFIX "Invalid link context\n");
 645                 return -1;
 646         }
 647
 648         /* TBD: Support multiple index (IRQ) entries per Link Device */
 649         if (index) {
 650                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 651                 return -1;
 652         }
 653
 654         mutex_lock(&acpi_link_lock);
 655         if (acpi_pci_link_allocate(link)) {
 656                 mutex_unlock(&acpi_link_lock);
 657                 return -1;
 658         }
 659
 660         if (!link->irq.active) {
 661                 mutex_unlock(&acpi_link_lock);
 662                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 663                 return -1;
 664         }
 665         link->refcnt++;
 666         mutex_unlock(&acpi_link_lock);
 667
 668         if (triggering)
 669                 *triggering = link->irq.triggering;
 670         if (polarity)
 671                 *polarity = link->irq.polarity;
 672         if (name)
 673                 *name = acpi_device_bid(link->device);
 674         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 675                           "Link %s is referenced\n",
 676                           acpi_device_bid(link->device)));
 677         return (link->irq.active);
 678 }
 679
 680 /*
 681  * We don't change link's irq information here.  After it is reenabled, we
 682  * continue use the info
 683  */
 684 int acpi_pci_link_free_irq(acpi_handle handle)
 685 {
 686         struct acpi_device *device;
 687         struct acpi_pci_link *link;
 688         acpi_status result;
 689
 690         result = acpi_bus_get_device(handle, &device);
 691         if (result) {
 692                 printk(KERN_ERR PREFIX "Invalid link device\n");
 693                 return -1;
 694         }
 695
 696         link = acpi_driver_data(device);
 697         if (!link) {
 698                 printk(KERN_ERR PREFIX "Invalid link context\n");
 699                 return -1;
 700         }
 701
 702         mutex_lock(&acpi_link_lock);
 703         if (!link->irq.initialized) {
 704                 mutex_unlock(&acpi_link_lock);
 705                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 706                 return -1;
 707         }
 708 #ifdef  FUTURE_USE
 709         /*
 710          * The Link reference count allows us to _DISable an unused link
 711          * and suspend time, and set it again  on resume.
 712          * However, 2.6.12 still has irq_router.resume
 713          * which blindly restores the link state.
 714          * So we disable the reference count method
 715          * to prevent duplicate acpi_pci_link_set()
 716          * which would harm some systems
 717          */
 718         link->refcnt--;
 719 #endif
 720         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 721                           "Link %s is dereferenced\n",
 722                           acpi_device_bid(link->device)));
 723
 724         if (link->refcnt == 0)
 725                 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 726
 727         mutex_unlock(&acpi_link_lock);
 728         return (link->irq.active);
 729 }
 730
 731 /* --------------------------------------------------------------------------
 732                                  Driver Interface
 733    -------------------------------------------------------------------------- */
 734
 735 static int acpi_pci_link_add(struct acpi_device *device,
 736                              const struct acpi_device_id *not_used)
 737 {
 738         int result;
 739         struct acpi_pci_link *link;
 740         int i;
 741         int found = 0;
 742
 743         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 744         if (!link)
 745                 return -ENOMEM;
 746
 747         link->device = device;
 748         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 749         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 750         device->driver_data = link;
 751
 752         mutex_lock(&acpi_link_lock);
 753         result = acpi_pci_link_get_possible(link);
 754         if (result)
 755                 goto end;
 756
 757         /* query and set link->irq.active */
 758         acpi_pci_link_get_current(link);
 759
 760         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 761                acpi_device_bid(device));
 762         for (i = 0; i < link->irq.possible_count; i++) {
 763                 if (link->irq.active == link->irq.possible[i]) {
 764                         printk(KERN_CONT " *%d", link->irq.possible[i]);
 765                         found = 1;
 766                 } else
 767                         printk(KERN_CONT " %d", link->irq.possible[i]);
 768         }
 769
 770         printk(KERN_CONT ")");
 771
 772         if (!found)
 773                 printk(KERN_CONT " *%d", link->irq.active);
 774
 775         if (!link->device->status.enabled)
 776                 printk(KERN_CONT ", disabled.");
 777
 778         printk(KERN_CONT "\n");
 779
 780         list_add_tail(&link->list, &acpi_link_list);
 781
 782       end:
 783         /* disable all links -- to be activated on use */
 784         acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 785         mutex_unlock(&acpi_link_lock);
 786
 787         if (result)
 788                 kfree(link);
 789
 790         return result < 0 ? result : 1;
 791 }
 792
 793 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 794 {
 795         if (link->refcnt && link->irq.active && link->irq.initialized)
 796                 return (acpi_pci_link_set(link, link->irq.active));
 797
 798         return 0;
 799 }
 800
 801 static void irqrouter_resume(void)
 802 {
 803         struct acpi_pci_link *link;
 804
 805         list_for_each_entry(link, &acpi_link_list, list) {
 806                 acpi_pci_link_resume(link);
 807         }
 808 }
 809
 810 static void acpi_pci_link_remove(struct acpi_device *device)
 811 {
 812         struct acpi_pci_link *link;
 813
 814         link = acpi_driver_data(device);
 815
 816         mutex_lock(&acpi_link_lock);
 817         list_del(&link->list);
 818         mutex_unlock(&acpi_link_lock);
 819
 820         kfree(link);
 821 }
 822
 823 /*
 824  * modify acpi_isa_irq_penalty[] from cmdline
 825  */
 826 static int __init acpi_irq_penalty_update(char *str, int used)
 827 {
 828         int i;
 829
 830         for (i = 0; i < 16; i++) {
 831                 int retval;
 832                 int irq;
 833                 int new_penalty;
 834
 835                 retval = get_option(&str, &irq);
 836
 837                 if (!retval)
 838                         break;  /* no number found */
 839
 840                 /* see if this is a ISA IRQ */
 841                 if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
 842                         continue;
 843
 844                 if (used)
 845                         new_penalty = acpi_isa_irq_penalty[irq] +
 846                                         PIRQ_PENALTY_ISA_USED;
 847                 else
 848                         new_penalty = 0;
 849
 850                 acpi_isa_irq_penalty[irq] = new_penalty;
 851                 if (retval != 2)        /* no next number */
 852                         break;
 853         }
 854         return 1;
 855 }
 856
 857 /*
 858  * We'd like PNP to call this routine for the
 859  * single ISA_USED value for each legacy device.
 860  * But instead it calls us with each POSSIBLE setting.
 861  * There is no ISA_POSSIBLE weight, so we simply use
 862  * the (small) PCI_USING penalty.
 863  */
 864 void acpi_penalize_isa_irq(int irq, int active)
 865 {
 866         if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
 867                 acpi_isa_irq_penalty[irq] +=
 868                   (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
 869 }
 870
 871 bool acpi_isa_irq_available(int irq)
 872 {
 873         return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
 874                     acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
 875 }
 876
 877 void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 878 {
 879         sci_irq = irq;
 880
 881         if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
 882             polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
 883                 sci_penalty = PIRQ_PENALTY_PCI_USING;
 884         else
 885                 sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
 886 }
 887
 888 /*
 889  * Over-ride default table to reserve additional IRQs for use by ISA
 890  * e.g. acpi_irq_isa=5
 891  * Useful for telling ACPI how not to interfere with your ISA sound card.
 892  */
 893 static int __init acpi_irq_isa(char *str)
 894 {
 895         return acpi_irq_penalty_update(str, 1);
 896 }
 897
 898 __setup("acpi_irq_isa=", acpi_irq_isa);
 899
 900 /*
 901  * Over-ride default table to free additional IRQs for use by PCI
 902  * e.g. acpi_irq_pci=7,15
 903  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 904  */
 905 static int __init acpi_irq_pci(char *str)
 906 {
 907         return acpi_irq_penalty_update(str, 0);
 908 }
 909
 910 __setup("acpi_irq_pci=", acpi_irq_pci);
 911
 912 static int __init acpi_irq_nobalance_set(char *str)
 913 {
 914         acpi_irq_balance = 0;
 915         return 1;
 916 }
 917
 918 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 919
 920 static int __init acpi_irq_balance_set(char *str)
 921 {
 922         acpi_irq_balance = 1;
 923         return 1;
 924 }
 925
 926 __setup("acpi_irq_balance", acpi_irq_balance_set);
 927
 928 static struct syscore_ops irqrouter_syscore_ops = {
 929         .resume = irqrouter_resume,
 930 };
 931
 932 void __init acpi_pci_link_init(void)
 933 {
 934         if (acpi_noirq)
 935                 return;
 936
 937         if (acpi_irq_balance == -1) {
 938                 /* no command line switch: enable balancing in IOAPIC mode */
 939                 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 940                         acpi_irq_balance = 1;
 941                 else
 942                         acpi_irq_balance = 0;
 943         }
 944         register_syscore_ops(&irqrouter_syscore_ops);
 945         acpi_scan_add_handler(&pci_link_handler);
 946 }