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
 111         switch (resource->type) {
 112         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 113                 return AE_OK;
 114         case ACPI_RESOURCE_TYPE_IRQ:
 115                 {
 116                         struct acpi_resource_irq *p = &resource->data.irq;
 117                         if (!p || !p->interrupt_count) {
 118                                 printk(KERN_WARNING PREFIX "Blank IRQ resource\n");
 119                                 return AE_OK;
 120                         }
 121                         for (i = 0;
 122                              (i < p->interrupt_count
 123                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 124                                 if (!p->interrupts[i]) {
 125                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
 126                                                       p->interrupts[i]);
 127                                         continue;
 128                                 }
 129                                 link->irq.possible[i] = p->interrupts[i];
 130                                 link->irq.possible_count++;
 131                         }
 132                         link->irq.triggering = p->triggering;
 133                         link->irq.polarity = p->polarity;
 134                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 135                         break;
 136                 }
 137         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 138                 {
 139                         struct acpi_resource_extended_irq *p =
 140                             &resource->data.extended_irq;
 141                         if (!p || !p->interrupt_count) {
 142                                 printk(KERN_WARNING PREFIX
 143                                               "Blank EXT IRQ resource\n");
 144                                 return AE_OK;
 145                         }
 146                         for (i = 0;
 147                              (i < p->interrupt_count
 148                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 149                                 if (!p->interrupts[i]) {
 150                                         printk(KERN_WARNING PREFIX "Invalid IRQ %d\n",
 151                                                       p->interrupts[i]);
 152                                         continue;
 153                                 }
 154                                 link->irq.possible[i] = p->interrupts[i];
 155                                 link->irq.possible_count++;
 156                         }
 157                         link->irq.triggering = p->triggering;
 158                         link->irq.polarity = p->polarity;
 159                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 160                         break;
 161                 }
 162         default:
 163                 printk(KERN_ERR PREFIX "Resource is not an IRQ entry\n");
 164                 return AE_OK;
 165         }
 166
 167         return AE_CTRL_TERMINATE;
 168 }
 169
 170 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 171 {
 172         acpi_status status;
 173
 174
 175         if (!link)
 176                 return -EINVAL;
 177
 178         status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
 179                                      acpi_pci_link_check_possible, link);
 180         if (ACPI_FAILURE(status)) {
 181                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 182                 return -ENODEV;
 183         }
 184
 185         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 186                           "Found %d possible IRQs\n",
 187                           link->irq.possible_count));
 188
 189         return 0;
 190 }
 191
 192 static acpi_status
 193 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
 194 {
 195         int *irq = (int *)context;
 196
 197
 198         switch (resource->type) {
 199         case ACPI_RESOURCE_TYPE_IRQ:
 200                 {
 201                         struct acpi_resource_irq *p = &resource->data.irq;
 202                         if (!p || !p->interrupt_count) {
 203                                 /*
 204                                  * IRQ descriptors may have no IRQ# bits set,
 205                                  * particularly those those w/ _STA disabled
 206                                  */
 207                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 208                                                   "Blank IRQ resource\n"));
 209                                 return AE_OK;
 210                         }
 211                         *irq = p->interrupts[0];
 212                         break;
 213                 }
 214         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 215                 {
 216                         struct acpi_resource_extended_irq *p =
 217                             &resource->data.extended_irq;
 218                         if (!p || !p->interrupt_count) {
 219                                 /*
 220                                  * extended IRQ descriptors must
 221                                  * return at least 1 IRQ
 222                                  */
 223                                 printk(KERN_WARNING PREFIX
 224                                               "Blank EXT IRQ resource\n");
 225                                 return AE_OK;
 226                         }
 227                         *irq = p->interrupts[0];
 228                         break;
 229                 }
 230                 break;
 231         default:
 232                 printk(KERN_ERR PREFIX "Resource %d isn't an IRQ\n", resource->type);
 233         case ACPI_RESOURCE_TYPE_END_TAG:
 234                 return AE_OK;
 235         }
 236         return AE_CTRL_TERMINATE;
 237 }
 238
 239 /*
 240  * Run _CRS and set link->irq.active
 241  *
 242  * return value:
 243  * 0 - success
 244  * !0 - failure
 245  */
 246 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 247 {
 248         int result = 0;
 249         acpi_status status = AE_OK;
 250         int irq = 0;
 251
 252
 253         if (!link || !link->handle)
 254                 return -EINVAL;
 255
 256         link->irq.active = 0;
 257
 258         /* in practice, status disabled is meaningless, ignore it */
 259         if (acpi_strict) {
 260                 /* Query _STA, set link->device->status */
 261                 result = acpi_bus_get_status(link->device);
 262                 if (result) {
 263                         printk(KERN_ERR PREFIX "Unable to read status\n");
 264                         goto end;
 265                 }
 266
 267                 if (!link->device->status.enabled) {
 268                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 269                         return 0;
 270                 }
 271         }
 272
 273         /*
 274          * Query and parse _CRS to get the current IRQ assignment.
 275          */
 276
 277         status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
 278                                      acpi_pci_link_check_current, &irq);
 279         if (ACPI_FAILURE(status)) {
 280                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 281                 result = -ENODEV;
 282                 goto end;
 283         }
 284
 285         if (acpi_strict && !irq) {
 286                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 287                 result = -ENODEV;
 288         }
 289
 290         link->irq.active = irq;
 291
 292         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 293
 294       end:
 295         return result;
 296 }
 297
 298 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 299 {
 300         int result = 0;
 301         acpi_status status = AE_OK;
 302         struct {
 303                 struct acpi_resource res;
 304                 struct acpi_resource end;
 305         } *resource;
 306         struct acpi_buffer buffer = { 0, NULL };
 307
 308
 309         if (!link || !irq)
 310                 return -EINVAL;
 311
 312         resource = kmalloc(sizeof(*resource) + 1, GFP_ATOMIC);
 313         if (!resource)
 314                 return -ENOMEM;
 315
 316         memset(resource, 0, sizeof(*resource) + 1);
 317         buffer.length = sizeof(*resource) + 1;
 318         buffer.pointer = resource;
 319
 320         switch (link->irq.resource_type) {
 321         case ACPI_RESOURCE_TYPE_IRQ:
 322                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 323                 resource->res.length = sizeof(struct acpi_resource);
 324                 resource->res.data.irq.triggering = link->irq.triggering;
 325                 resource->res.data.irq.polarity =
 326                     link->irq.polarity;
 327                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 328                         resource->res.data.irq.sharable =
 329                             ACPI_EXCLUSIVE;
 330                 else
 331                         resource->res.data.irq.sharable = ACPI_SHARED;
 332                 resource->res.data.irq.interrupt_count = 1;
 333                 resource->res.data.irq.interrupts[0] = irq;
 334                 break;
 335
 336         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 337                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 338                 resource->res.length = sizeof(struct acpi_resource);
 339                 resource->res.data.extended_irq.producer_consumer =
 340                     ACPI_CONSUMER;
 341                 resource->res.data.extended_irq.triggering =
 342                     link->irq.triggering;
 343                 resource->res.data.extended_irq.polarity =
 344                     link->irq.polarity;
 345                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 346                         resource->res.data.irq.sharable =
 347                             ACPI_EXCLUSIVE;
 348                 else
 349                         resource->res.data.irq.sharable = ACPI_SHARED;
 350                 resource->res.data.extended_irq.interrupt_count = 1;
 351                 resource->res.data.extended_irq.interrupts[0] = irq;
 352                 /* ignore resource_source, it's optional */
 353                 break;
 354         default:
 355                 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 356                 result = -EINVAL;
 357                 goto end;
 358
 359         }
 360         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 361
 362         /* Attempt to set the resource */
 363         status = acpi_set_current_resources(link->handle, &buffer);
 364
 365         /* check for total failure */
 366         if (ACPI_FAILURE(status)) {
 367                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 368                 result = -ENODEV;
 369                 goto end;
 370         }
 371
 372         /* Query _STA, set device->status */
 373         result = acpi_bus_get_status(link->device);
 374         if (result) {
 375                 printk(KERN_ERR PREFIX "Unable to read status\n");
 376                 goto end;
 377         }
 378         if (!link->device->status.enabled) {
 379                 printk(KERN_WARNING PREFIX
 380                               "%s [%s] disabled and referenced, BIOS bug\n",
 381                               acpi_device_name(link->device),
 382                               acpi_device_bid(link->device));
 383         }
 384
 385         /* Query _CRS, set link->irq.active */
 386         result = acpi_pci_link_get_current(link);
 387         if (result) {
 388                 goto end;
 389         }
 390
 391         /*
 392          * Is current setting not what we set?
 393          * set link->irq.active
 394          */
 395         if (link->irq.active != irq) {
 396                 /*
 397                  * policy: when _CRS doesn't return what we just _SRS
 398                  * assume _SRS worked and override _CRS value.
 399                  */
 400                 printk(KERN_WARNING PREFIX
 401                               "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 402                               acpi_device_name(link->device),
 403                               acpi_device_bid(link->device), link->irq.active, irq);
 404                 link->irq.active = irq;
 405         }
 406
 407         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 408
 409       end:
 410         kfree(resource);
 411         return result;
 412 }
 413
 414 /* --------------------------------------------------------------------------
 415                             PCI Link IRQ Management
 416    -------------------------------------------------------------------------- */
 417
 418 /*
 419  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 420  * Link Devices to move the PIRQs around to minimize sharing.
 421  *
 422  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 423  * that the BIOS has already set to active.  This is necessary because
 424  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 425  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 426  * even if acpi_irq_nobalance is set.
 427  *
 428  * A tables of penalties avoids directing PCI interrupts to well known
 429  * ISA IRQs. Boot params are available to over-ride the default table:
 430  *
 431  * List interrupts that are free for PCI use.
 432  * acpi_irq_pci=n[,m]
 433  *
 434  * List interrupts that should not be used for PCI:
 435  * acpi_irq_isa=n[,m]
 436  *
 437  * Note that PCI IRQ routers have a list of possible IRQs,
 438  * which may not include the IRQs this table says are available.
 439  *
 440  * Since this heuristic can't tell the difference between a link
 441  * that no device will attach to, vs. a link which may be shared
 442  * by multiple active devices -- it is not optimal.
 443  *
 444  * If interrupt performance is that important, get an IO-APIC system
 445  * with a pin dedicated to each device.  Or for that matter, an MSI
 446  * enabled system.
 447  */
 448
 449 #define ACPI_MAX_IRQS           256
 450 #define ACPI_MAX_ISA_IRQ        16
 451
 452 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 453 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 454 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 455 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 456 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 457 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 458
 459 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 460         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 461         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 462         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 463         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 464         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 465         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 466         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 467         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 468         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 469         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 470         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 471         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 472         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 473         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 474         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 475         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 476         /* >IRQ15 */
 477 };
 478
 479 int __init acpi_irq_penalty_init(void)
 480 {
 481         struct list_head *node = NULL;
 482         struct acpi_pci_link *link = NULL;
 483         int i = 0;
 484
 485
 486         /*
 487          * Update penalties to facilitate IRQ balancing.
 488          */
 489         list_for_each(node, &acpi_link.entries) {
 490
 491                 link = list_entry(node, struct acpi_pci_link, node);
 492                 if (!link) {
 493                         printk(KERN_ERR PREFIX "Invalid link context\n");
 494                         continue;
 495                 }
 496
 497                 /*
 498                  * reflect the possible and active irqs in the penalty table --
 499                  * useful for breaking ties.
 500                  */
 501                 if (link->irq.possible_count) {
 502                         int penalty =
 503                             PIRQ_PENALTY_PCI_POSSIBLE /
 504                             link->irq.possible_count;
 505
 506                         for (i = 0; i < link->irq.possible_count; i++) {
 507                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 508                                         acpi_irq_penalty[link->irq.
 509                                                          possible[i]] +=
 510                                             penalty;
 511                         }
 512
 513                 } else if (link->irq.active) {
 514                         acpi_irq_penalty[link->irq.active] +=
 515                             PIRQ_PENALTY_PCI_POSSIBLE;
 516                 }
 517         }
 518         /* Add a penalty for the SCI */
 519         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 520
 521         return 0;
 522 }
 523
 524 static int acpi_irq_balance;    /* 0: static, 1: balance */
 525
 526 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 527 {
 528         int irq;
 529         int i;
 530
 531
 532         if (link->irq.initialized) {
 533                 if (link->refcnt == 0)
 534                         /* This means the link is disabled but initialized */
 535                         acpi_pci_link_set(link, link->irq.active);
 536                 return 0;
 537         }
 538
 539         /*
 540          * search for active IRQ in list of possible IRQs.
 541          */
 542         for (i = 0; i < link->irq.possible_count; ++i) {
 543                 if (link->irq.active == link->irq.possible[i])
 544                         break;
 545         }
 546         /*
 547          * forget active IRQ that is not in possible list
 548          */
 549         if (i == link->irq.possible_count) {
 550                 if (acpi_strict)
 551                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 552                                       " in _PRS\n", link->irq.active);
 553                 link->irq.active = 0;
 554         }
 555
 556         /*
 557          * if active found, use it; else pick entry from end of possible list.
 558          */
 559         if (link->irq.active) {
 560                 irq = link->irq.active;
 561         } else {
 562                 irq = link->irq.possible[link->irq.possible_count - 1];
 563         }
 564
 565         if (acpi_irq_balance || !link->irq.active) {
 566                 /*
 567                  * Select the best IRQ.  This is done in reverse to promote
 568                  * the use of IRQs 9, 10, 11, and >15.
 569                  */
 570                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 571                         if (acpi_irq_penalty[irq] >
 572                             acpi_irq_penalty[link->irq.possible[i]])
 573                                 irq = link->irq.possible[i];
 574                 }
 575         }
 576
 577         /* Attempt to enable the link device at this IRQ. */
 578         if (acpi_pci_link_set(link, irq)) {
 579                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 580                             "Try pci=noacpi or acpi=off\n",
 581                             acpi_device_name(link->device),
 582                             acpi_device_bid(link->device));
 583                 return -ENODEV;
 584         } else {
 585                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 586                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 587                        acpi_device_name(link->device),
 588                        acpi_device_bid(link->device), link->irq.active);
 589         }
 590
 591         link->irq.initialized = 1;
 592
 593         return 0;
 594 }
 595
 596 /*
 597  * acpi_pci_link_allocate_irq
 598  * success: return IRQ >= 0
 599  * failure: return -1
 600  */
 601
 602 int
 603 acpi_pci_link_allocate_irq(acpi_handle handle,
 604                            int index,
 605                            int *triggering, int *polarity, char **name)
 606 {
 607         int result = 0;
 608         struct acpi_device *device = NULL;
 609         struct acpi_pci_link *link = NULL;
 610
 611
 612         result = acpi_bus_get_device(handle, &device);
 613         if (result) {
 614                 printk(KERN_ERR PREFIX "Invalid link device\n");
 615                 return -1;
 616         }
 617
 618         link = (struct acpi_pci_link *)acpi_driver_data(device);
 619         if (!link) {
 620                 printk(KERN_ERR PREFIX "Invalid link context\n");
 621                 return -1;
 622         }
 623
 624         /* TBD: Support multiple index (IRQ) entries per Link Device */
 625         if (index) {
 626                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 627                 return -1;
 628         }
 629
 630         mutex_lock(&acpi_link_lock);
 631         if (acpi_pci_link_allocate(link)) {
 632                 mutex_unlock(&acpi_link_lock);
 633                 return -1;
 634         }
 635
 636         if (!link->irq.active) {
 637                 mutex_unlock(&acpi_link_lock);
 638                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 639                 return -1;
 640         }
 641         link->refcnt++;
 642         mutex_unlock(&acpi_link_lock);
 643
 644         if (triggering)
 645                 *triggering = link->irq.triggering;
 646         if (polarity)
 647                 *polarity = link->irq.polarity;
 648         if (name)
 649                 *name = acpi_device_bid(link->device);
 650         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 651                           "Link %s is referenced\n",
 652                           acpi_device_bid(link->device)));
 653         return (link->irq.active);
 654 }
 655
 656 /*
 657  * We don't change link's irq information here.  After it is reenabled, we
 658  * continue use the info
 659  */
 660 int acpi_pci_link_free_irq(acpi_handle handle)
 661 {
 662         struct acpi_device *device = NULL;
 663         struct acpi_pci_link *link = NULL;
 664         acpi_status result;
 665
 666
 667         result = acpi_bus_get_device(handle, &device);
 668         if (result) {
 669                 printk(KERN_ERR PREFIX "Invalid link device\n");
 670                 return -1;
 671         }
 672
 673         link = (struct acpi_pci_link *)acpi_driver_data(device);
 674         if (!link) {
 675                 printk(KERN_ERR PREFIX "Invalid link context\n");
 676                 return -1;
 677         }
 678
 679         mutex_lock(&acpi_link_lock);
 680         if (!link->irq.initialized) {
 681                 mutex_unlock(&acpi_link_lock);
 682                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 683                 return -1;
 684         }
 685 #ifdef  FUTURE_USE
 686         /*
 687          * The Link reference count allows us to _DISable an unused link
 688          * and suspend time, and set it again  on resume.
 689          * However, 2.6.12 still has irq_router.resume
 690          * which blindly restores the link state.
 691          * So we disable the reference count method
 692          * to prevent duplicate acpi_pci_link_set()
 693          * which would harm some systems
 694          */
 695         link->refcnt--;
 696 #endif
 697         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 698                           "Link %s is dereferenced\n",
 699                           acpi_device_bid(link->device)));
 700
 701         if (link->refcnt == 0) {
 702                 acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 703         }
 704         mutex_unlock(&acpi_link_lock);
 705         return (link->irq.active);
 706 }
 707
 708 /* --------------------------------------------------------------------------
 709                                  Driver Interface
 710    -------------------------------------------------------------------------- */
 711
 712 static int acpi_pci_link_add(struct acpi_device *device)
 713 {
 714         int result = 0;
 715         struct acpi_pci_link *link = NULL;
 716         int i = 0;
 717         int found = 0;
 718
 719
 720         if (!device)
 721                 return -EINVAL;
 722
 723         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 724         if (!link)
 725                 return -ENOMEM;
 726         memset(link, 0, sizeof(struct acpi_pci_link));
 727
 728         link->device = device;
 729         link->handle = device->handle;
 730         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 731         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 732         acpi_driver_data(device) = link;
 733
 734         mutex_lock(&acpi_link_lock);
 735         result = acpi_pci_link_get_possible(link);
 736         if (result)
 737                 goto end;
 738
 739         /* query and set link->irq.active */
 740         acpi_pci_link_get_current(link);
 741
 742         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 743                acpi_device_bid(device));
 744         for (i = 0; i < link->irq.possible_count; i++) {
 745                 if (link->irq.active == link->irq.possible[i]) {
 746                         printk(" *%d", link->irq.possible[i]);
 747                         found = 1;
 748                 } else
 749                         printk(" %d", link->irq.possible[i]);
 750         }
 751
 752         printk(")");
 753
 754         if (!found)
 755                 printk(" *%d", link->irq.active);
 756
 757         if (!link->device->status.enabled)
 758                 printk(", disabled.");
 759
 760         printk("\n");
 761
 762         /* TBD: Acquire/release lock */
 763         list_add_tail(&link->node, &acpi_link.entries);
 764         acpi_link.count++;
 765
 766       end:
 767         /* disable all links -- to be activated on use */
 768         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 769         mutex_unlock(&acpi_link_lock);
 770
 771         if (result)
 772                 kfree(link);
 773
 774         return result;
 775 }
 776
 777 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 778 {
 779
 780         if (link->refcnt && link->irq.active && link->irq.initialized)
 781                 return (acpi_pci_link_set(link, link->irq.active));
 782         else
 783                 return 0;
 784 }
 785
 786 /*
 787  * FIXME: this is a workaround to avoid nasty warning.  It will be removed
 788  * after every device calls pci_disable_device in .resume.
 789  */
 790 int acpi_in_resume;
 791 static int irqrouter_resume(struct sys_device *dev)
 792 {
 793         struct list_head *node = NULL;
 794         struct acpi_pci_link *link = NULL;
 795
 796
 797         /* Make sure SCI is enabled again (Apple firmware bug?) */
 798         acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1, ACPI_MTX_DO_NOT_LOCK);
 799
 800         acpi_in_resume = 1;
 801         list_for_each(node, &acpi_link.entries) {
 802                 link = list_entry(node, struct acpi_pci_link, node);
 803                 if (!link) {
 804                         printk(KERN_ERR PREFIX "Invalid link context\n");
 805                         continue;
 806                 }
 807                 acpi_pci_link_resume(link);
 808         }
 809         acpi_in_resume = 0;
 810         return 0;
 811 }
 812
 813 static int acpi_pci_link_remove(struct acpi_device *device, int type)
 814 {
 815         struct acpi_pci_link *link = NULL;
 816
 817
 818         if (!device || !acpi_driver_data(device))
 819                 return -EINVAL;
 820
 821         link = (struct acpi_pci_link *)acpi_driver_data(device);
 822
 823         mutex_lock(&acpi_link_lock);
 824         list_del(&link->node);
 825         mutex_unlock(&acpi_link_lock);
 826
 827         kfree(link);
 828
 829         return 0;
 830 }
 831
 832 /*
 833  * modify acpi_irq_penalty[] from cmdline
 834  */
 835 static int __init acpi_irq_penalty_update(char *str, int used)
 836 {
 837         int i;
 838
 839         for (i = 0; i < 16; i++) {
 840                 int retval;
 841                 int irq;
 842
 843                 retval = get_option(&str, &irq);
 844
 845                 if (!retval)
 846                         break;  /* no number found */
 847
 848                 if (irq < 0)
 849                         continue;
 850
 851                 if (irq >= ACPI_MAX_IRQS)
 852                         continue;
 853
 854                 if (used)
 855                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 856                 else
 857                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 858
 859                 if (retval != 2)        /* no next number */
 860                         break;
 861         }
 862         return 1;
 863 }
 864
 865 /*
 866  * We'd like PNP to call this routine for the
 867  * single ISA_USED value for each legacy device.
 868  * But instead it calls us with each POSSIBLE setting.
 869  * There is no ISA_POSSIBLE weight, so we simply use
 870  * the (small) PCI_USING penalty.
 871  */
 872 void acpi_penalize_isa_irq(int irq, int active)
 873 {
 874         if (active)
 875                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 876         else
 877                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 878 }
 879
 880 /*
 881  * Over-ride default table to reserve additional IRQs for use by ISA
 882  * e.g. acpi_irq_isa=5
 883  * Useful for telling ACPI how not to interfere with your ISA sound card.
 884  */
 885 static int __init acpi_irq_isa(char *str)
 886 {
 887         return acpi_irq_penalty_update(str, 1);
 888 }
 889
 890 __setup("acpi_irq_isa=", acpi_irq_isa);
 891
 892 /*
 893  * Over-ride default table to free additional IRQs for use by PCI
 894  * e.g. acpi_irq_pci=7,15
 895  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 896  */
 897 static int __init acpi_irq_pci(char *str)
 898 {
 899         return acpi_irq_penalty_update(str, 0);
 900 }
 901
 902 __setup("acpi_irq_pci=", acpi_irq_pci);
 903
 904 static int __init acpi_irq_nobalance_set(char *str)
 905 {
 906         acpi_irq_balance = 0;
 907         return 1;
 908 }
 909
 910 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 911
 912 int __init acpi_irq_balance_set(char *str)
 913 {
 914         acpi_irq_balance = 1;
 915         return 1;
 916 }
 917
 918 __setup("acpi_irq_balance", acpi_irq_balance_set);
 919
 920 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 921 static struct sysdev_class irqrouter_sysdev_class = {
 922         set_kset_name("irqrouter"),
 923         .resume = irqrouter_resume,
 924 };
 925
 926 static struct sys_device device_irqrouter = {
 927         .id = 0,
 928         .cls = &irqrouter_sysdev_class,
 929 };
 930
 931 static int __init irqrouter_init_sysfs(void)
 932 {
 933         int error;
 934
 935
 936         if (acpi_disabled || acpi_noirq)
 937                 return 0;
 938
 939         error = sysdev_class_register(&irqrouter_sysdev_class);
 940         if (!error)
 941                 error = sysdev_register(&device_irqrouter);
 942
 943         return error;
 944 }
 945
 946 device_initcall(irqrouter_init_sysfs);
 947
 948 static int __init acpi_pci_link_init(void)
 949 {
 950
 951         if (acpi_noirq)
 952                 return 0;
 953
 954         acpi_link.count = 0;
 955         INIT_LIST_HEAD(&acpi_link.entries);
 956
 957         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 958                 return -ENODEV;
 959
 960         return 0;
 961 }
 962
 963 subsys_initcall(acpi_pci_link_init);