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/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/types.h>
  36 #include <linux/proc_fs.h>
  37 #include <linux/spinlock.h>
  38 #include <linux/pm.h>
  39 #include <linux/pci.h>
  40
  41 #include <acpi/acpi_bus.h>
  42 #include <acpi/acpi_drivers.h>
  43
  44
  45 #define _COMPONENT              ACPI_PCI_COMPONENT
  46 ACPI_MODULE_NAME                ("pci_link")
  47
  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
  55 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  56
  57 static int acpi_pci_link_add (struct acpi_device *device);
  58 static int acpi_pci_link_remove (struct acpi_device *device, int type);
  59
  60 static struct acpi_driver acpi_pci_link_driver = {
  61         .name =         ACPI_PCI_LINK_DRIVER_NAME,
  62         .class =        ACPI_PCI_LINK_CLASS,
  63         .ids =          ACPI_PCI_LINK_HID,
  64         .ops =          {
  65                                 .add =    acpi_pci_link_add,
  66                                 .remove = acpi_pci_link_remove,
  67                         },
  68 };
  69
  70 struct acpi_pci_link_irq {
  71         u8                      active;                 /* Current IRQ */
  72         u8                      edge_level;             /* All IRQs */
  73         u8                      active_high_low;        /* All IRQs */
  74         u8                      setonboot;
  75         u8                      resource_type;
  76         u8                      possible_count;
  77         u8                      possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  78 };
  79
  80 struct acpi_pci_link {
  81         struct list_head        node;
  82         struct acpi_device      *device;
  83         acpi_handle             handle;
  84         struct acpi_pci_link_irq irq;
  85 };
  86
  87 static struct {
  88         int                     count;
  89         struct list_head        entries;
  90 }                               acpi_link;
  91
  92
  93 /* --------------------------------------------------------------------------
  94                             PCI Link Device Management
  95    -------------------------------------------------------------------------- */
  96
  97 /*
  98  * set context (link) possible list from resource list
  99  */
 100 static acpi_status
 101 acpi_pci_link_check_possible (
 102         struct acpi_resource    *resource,
 103         void                    *context)
 104 {
 105         struct acpi_pci_link    *link = (struct acpi_pci_link *) context;
 106         u32                     i = 0;
 107
 108         ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
 109
 110         switch (resource->id) {
 111         case ACPI_RSTYPE_START_DPF:
 112                 return AE_OK;
 113         case ACPI_RSTYPE_IRQ:
 114         {
 115                 struct acpi_resource_irq *p = &resource->data.irq;
 116                 if (!p || !p->number_of_interrupts) {
 117                         ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Blank IRQ resource\n"));
 118                         return AE_OK;
 119                 }
 120                 for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 121                         if (!p->interrupts[i]) {
 122                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 123                                 continue;
 124                         }
 125                         link->irq.possible[i] = p->interrupts[i];
 126                         link->irq.possible_count++;
 127                 }
 128                 link->irq.edge_level = p->edge_level;
 129                 link->irq.active_high_low = p->active_high_low;
 130                 link->irq.resource_type = ACPI_RSTYPE_IRQ;
 131                 break;
 132         }
 133         case ACPI_RSTYPE_EXT_IRQ:
 134         {
 135                 struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 136                 if (!p || !p->number_of_interrupts) {
 137                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 138                                 "Blank EXT IRQ resource\n"));
 139                         return AE_OK;
 140                 }
 141                 for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 142                         if (!p->interrupts[i]) {
 143                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 144                                 continue;
 145                         }
 146                         link->irq.possible[i] = p->interrupts[i];
 147                         link->irq.possible_count++;
 148                 }
 149                 link->irq.edge_level = p->edge_level;
 150                 link->irq.active_high_low = p->active_high_low;
 151                 link->irq.resource_type = ACPI_RSTYPE_EXT_IRQ;
 152                 break;
 153         }
 154         default:
 155                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 156                         "Resource is not an IRQ entry\n"));
 157                 return AE_OK;
 158         }
 159
 160         return AE_CTRL_TERMINATE;
 161 }
 162
 163
 164 static int
 165 acpi_pci_link_get_possible (
 166         struct acpi_pci_link    *link)
 167 {
 168         acpi_status             status;
 169
 170         ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
 171
 172         if (!link)
 173                 return_VALUE(-EINVAL);
 174
 175         status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
 176                         acpi_pci_link_check_possible, link);
 177         if (ACPI_FAILURE(status)) {
 178                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
 179                 return_VALUE(-ENODEV);
 180         }
 181
 182         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 183                 "Found %d possible IRQs\n", link->irq.possible_count));
 184
 185         return_VALUE(0);
 186 }
 187
 188
 189 static acpi_status
 190 acpi_pci_link_check_current (
 191         struct acpi_resource    *resource,
 192         void                    *context)
 193 {
 194         int                     *irq = (int *) context;
 195
 196         ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
 197
 198         switch (resource->id) {
 199         case ACPI_RSTYPE_IRQ:
 200         {
 201                 struct acpi_resource_irq *p = &resource->data.irq;
 202                 if (!p || !p->number_of_interrupts) {
 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_RSTYPE_EXT_IRQ:
 215         {
 216                 struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 217                 if (!p || !p->number_of_interrupts) {
 218                         /*
 219                          * extended IRQ descriptors must
 220                          * return at least 1 IRQ
 221                          */
 222                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 223                                 "Blank EXT IRQ resource\n"));
 224                         return AE_OK;
 225                 }
 226                 *irq = p->interrupts[0];
 227                 break;
 228         }
 229         default:
 230                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 231                         "Resource isn't an IRQ\n"));
 232                 return AE_OK;
 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
 245 acpi_pci_link_get_current (
 246         struct acpi_pci_link    *link)
 247 {
 248         int                     result = 0;
 249         acpi_status             status = AE_OK;
 250         int                     irq = 0;
 251
 252         ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
 253
 254         if (!link || !link->handle)
 255                 return_VALUE(-EINVAL);
 256
 257         link->irq.active = 0;
 258
 259         /* in practice, status disabled is meaningless, ignore it */
 260         if (acpi_strict) {
 261                 /* Query _STA, set link->device->status */
 262                 result = acpi_bus_get_status(link->device);
 263                 if (result) {
 264                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 265                         goto end;
 266                 }
 267
 268                 if (!link->device->status.enabled) {
 269                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 270                         return_VALUE(0);
 271                 }
 272         }
 273
 274         /*
 275          * Query and parse _CRS to get the current IRQ assignment.
 276          */
 277
 278         status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
 279                         acpi_pci_link_check_current, &irq);
 280         if (ACPI_FAILURE(status)) {
 281                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
 282                 result = -ENODEV;
 283                 goto end;
 284         }
 285
 286         if (acpi_strict && !irq) {
 287                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
 288                 result = -ENODEV;
 289         }
 290
 291         link->irq.active = irq;
 292
 293         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 294
 295 end:
 296         return_VALUE(result);
 297 }
 298
 299 static int
 300 acpi_pci_link_set (
 301         struct acpi_pci_link    *link,
 302         int                     irq)
 303 {
 304         int                     result = 0;
 305         acpi_status             status = AE_OK;
 306         struct {
 307                 struct acpi_resource    res;
 308                 struct acpi_resource    end;
 309         }                       resource;
 310         struct acpi_buffer      buffer = {sizeof(resource)+1, &resource};
 311         int                     i = 0;
 312         int                     valid = 0;
 313
 314         ACPI_FUNCTION_TRACE("acpi_pci_link_set");
 315
 316         if (!link || !irq)
 317                 return_VALUE(-EINVAL);
 318
 319         /* We don't check irqs the first time around */
 320         if (link->irq.setonboot) {
 321                 /* See if we're already at the target IRQ. */
 322                 if (irq == link->irq.active)
 323                         return_VALUE(0);
 324
 325                 /* Make sure the target IRQ in the list of possible IRQs. */
 326                 for (i=0; i<link->irq.possible_count; i++) {
 327                         if (irq == link->irq.possible[i])
 328                                 valid = 1;
 329                 }
 330                 if (!valid) {
 331                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Target IRQ %d invalid\n", irq));
 332                         return_VALUE(-EINVAL);
 333                 }
 334         }
 335
 336         memset(&resource, 0, sizeof(resource));
 337
 338         switch(link->irq.resource_type) {
 339         case ACPI_RSTYPE_IRQ:
 340                 resource.res.id = ACPI_RSTYPE_IRQ;
 341                 resource.res.length = sizeof(struct acpi_resource);
 342                 resource.res.data.irq.edge_level = link->irq.edge_level;
 343                 resource.res.data.irq.active_high_low = link->irq.active_high_low;
 344                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 345                         resource.res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 346                 else
 347                         resource.res.data.irq.shared_exclusive = ACPI_SHARED;
 348                 resource.res.data.irq.number_of_interrupts = 1;
 349                 resource.res.data.irq.interrupts[0] = irq;
 350                 break;
 351
 352         case ACPI_RSTYPE_EXT_IRQ:
 353                 resource.res.id = ACPI_RSTYPE_EXT_IRQ;
 354                 resource.res.length = sizeof(struct acpi_resource);
 355                 resource.res.data.extended_irq.producer_consumer = ACPI_CONSUMER;
 356                 resource.res.data.extended_irq.edge_level = link->irq.edge_level;
 357                 resource.res.data.extended_irq.active_high_low = link->irq.active_high_low;
 358                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 359                         resource.res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 360                 else
 361                         resource.res.data.irq.shared_exclusive = ACPI_SHARED;
 362                 resource.res.data.extended_irq.number_of_interrupts = 1;
 363                 resource.res.data.extended_irq.interrupts[0] = irq;
 364                 /* ignore resource_source, it's optional */
 365                 break;
 366         default:
 367                 printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
 368                 return_VALUE(-EINVAL);
 369
 370         }
 371         resource.end.id = ACPI_RSTYPE_END_TAG;
 372
 373         /* Attempt to set the resource */
 374         status = acpi_set_current_resources(link->handle, &buffer);
 375
 376         /* check for total failure */
 377         if (ACPI_FAILURE(status)) {
 378                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
 379                 return_VALUE(-ENODEV);
 380         }
 381
 382         /* Query _STA, set device->status */
 383         result = acpi_bus_get_status(link->device);
 384         if (result) {
 385                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 386                 return_VALUE(result);
 387         }
 388         if (!link->device->status.enabled) {
 389                 printk(KERN_WARNING PREFIX
 390                         "%s [%s] disabled and referenced, BIOS bug.\n",
 391                         acpi_device_name(link->device),
 392                         acpi_device_bid(link->device));
 393         }
 394
 395         /* Query _CRS, set link->irq.active */
 396         result = acpi_pci_link_get_current(link);
 397         if (result) {
 398                 return_VALUE(result);
 399         }
 400
 401         /*
 402          * Is current setting not what we set?
 403          * set link->irq.active
 404          */
 405         if (link->irq.active != irq) {
 406                 /*
 407                  * policy: when _CRS doesn't return what we just _SRS
 408                  * assume _SRS worked and override _CRS value.
 409                  */
 410                 printk(KERN_WARNING PREFIX
 411                         "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 412                         acpi_device_name(link->device),
 413                         acpi_device_bid(link->device),
 414                         link->irq.active, irq);
 415                 link->irq.active = irq;
 416         }
 417
 418         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 419
 420         return_VALUE(0);
 421 }
 422
 423
 424 /* --------------------------------------------------------------------------
 425                             PCI Link IRQ Management
 426    -------------------------------------------------------------------------- */
 427
 428 /*
 429  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 430  * Link Devices to move the PIRQs around to minimize sharing.
 431  *
 432  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 433  * that the BIOS has already set to active.  This is necessary because
 434  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 435  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 436  * even if acpi_irq_nobalance is set.
 437  *
 438  * A tables of penalties avoids directing PCI interrupts to well known
 439  * ISA IRQs. Boot params are available to over-ride the default table:
 440  *
 441  * List interrupts that are free for PCI use.
 442  * acpi_irq_pci=n[,m]
 443  *
 444  * List interrupts that should not be used for PCI:
 445  * acpi_irq_isa=n[,m]
 446  *
 447  * Note that PCI IRQ routers have a list of possible IRQs,
 448  * which may not include the IRQs this table says are available.
 449  *
 450  * Since this heuristic can't tell the difference between a link
 451  * that no device will attach to, vs. a link which may be shared
 452  * by multiple active devices -- it is not optimal.
 453  *
 454  * If interrupt performance is that important, get an IO-APIC system
 455  * with a pin dedicated to each device.  Or for that matter, an MSI
 456  * enabled system.
 457  */
 458
 459 #define ACPI_MAX_IRQS           256
 460 #define ACPI_MAX_ISA_IRQ        16
 461
 462 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 463 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 464 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 465 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 466 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 467 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 468
 469 static int __initdata acpi_irq_penalty[ACPI_MAX_IRQS] = {
 470         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 471         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 472         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 473         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 474         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 475         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 476         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 477         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 478         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 479         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 480         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 481         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 482         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 483         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 484         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 485         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 486                         /* >IRQ15 */
 487 };
 488
 489 int
 490 acpi_pci_link_check (void)
 491 {
 492         struct list_head        *node = NULL;
 493         struct acpi_pci_link    *link = NULL;
 494         int                     i = 0;
 495
 496         ACPI_FUNCTION_TRACE("acpi_pci_link_check");
 497
 498         /*
 499          * Update penalties to facilitate IRQ balancing.
 500          */
 501         list_for_each(node, &acpi_link.entries) {
 502
 503                 link = list_entry(node, struct acpi_pci_link, node);
 504                 if (!link) {
 505                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 506                         continue;
 507                 }
 508
 509                 /*
 510                  * reflect the possible and active irqs in the penalty table --
 511                  * useful for breaking ties.
 512                  */
 513                 if (link->irq.possible_count) {
 514                         int penalty = PIRQ_PENALTY_PCI_POSSIBLE / link->irq.possible_count;
 515
 516                         for (i = 0; i < link->irq.possible_count; i++) {
 517                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 518                                         acpi_irq_penalty[link->irq.possible[i]] += penalty;
 519                         }
 520
 521                 } else if (link->irq.active) {
 522                         acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_POSSIBLE;
 523                 }
 524         }
 525         /* Add a penalty for the SCI */
 526         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 527
 528         return_VALUE(0);
 529 }
 530
 531 static int acpi_irq_balance;    /* 0: static, 1: balance */
 532
 533 static int acpi_pci_link_allocate(struct acpi_pci_link* link) {
 534         int irq;
 535         int i;
 536
 537         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 538
 539         if (link->irq.setonboot)
 540                 return_VALUE(0);
 541
 542         /*
 543          * search for active IRQ in list of possible IRQs.
 544          */
 545         for (i = 0; i < link->irq.possible_count; ++i) {
 546                 if (link->irq.active == link->irq.possible[i])
 547                         break;
 548         }
 549         /*
 550          * forget active IRQ that is not in possible list
 551          */
 552         if (i == link->irq.possible_count) {
 553                 if (acpi_strict)
 554                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 555                                 " in _PRS\n", link->irq.active);
 556                 link->irq.active = 0;
 557         }
 558
 559         /*
 560          * if active found, use it; else pick entry from end of possible list.
 561          */
 562         if (link->irq.active) {
 563                 irq = link->irq.active;
 564         } else {
 565                 irq = link->irq.possible[link->irq.possible_count - 1];
 566         }
 567
 568         if (acpi_irq_balance || !link->irq.active) {
 569                 /*
 570                  * Select the best IRQ.  This is done in reverse to promote
 571                  * the use of IRQs 9, 10, 11, and >15.
 572                  */
 573                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 574                         if (acpi_irq_penalty[irq] > acpi_irq_penalty[link->irq.possible[i]])
 575                                 irq = link->irq.possible[i];
 576                 }
 577         }
 578
 579         /* Attempt to enable the link device at this IRQ. */
 580         if (acpi_pci_link_set(link, irq)) {
 581                 printk(PREFIX "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
 582                                 "Try pci=noacpi or acpi=off\n",
 583                         acpi_device_name(link->device),
 584                         acpi_device_bid(link->device));
 585                 return_VALUE(-ENODEV);
 586         } else {
 587                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 588                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 589                         acpi_device_name(link->device),
 590                         acpi_device_bid(link->device), link->irq.active);
 591         }
 592
 593         link->irq.setonboot = 1;
 594
 595         return_VALUE(0);
 596 }
 597
 598
 599 int
 600 acpi_pci_link_get_irq (
 601         acpi_handle             handle,
 602         int                     index,
 603         int*                    edge_level,
 604         int*                    active_high_low)
 605 {
 606         int                     result = 0;
 607         struct acpi_device      *device = NULL;
 608         struct acpi_pci_link    *link = NULL;
 609
 610         ACPI_FUNCTION_TRACE("acpi_pci_link_get_irq");
 611
 612         result = acpi_bus_get_device(handle, &device);
 613         if (result) {
 614                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 615                 return_VALUE(0);
 616         }
 617
 618         link = (struct acpi_pci_link *) acpi_driver_data(device);
 619         if (!link) {
 620                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 621                 return_VALUE(0);
 622         }
 623
 624         /* TBD: Support multiple index (IRQ) entries per Link Device */
 625         if (index) {
 626                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
 627                 return_VALUE(0);
 628         }
 629
 630         if (acpi_pci_link_allocate(link))
 631                 return_VALUE(0);
 632
 633         if (!link->irq.active) {
 634                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
 635                 return_VALUE(0);
 636         }
 637
 638         if (edge_level) *edge_level = link->irq.edge_level;
 639         if (active_high_low) *active_high_low = link->irq.active_high_low;
 640         return_VALUE(link->irq.active);
 641 }
 642
 643
 644 /* --------------------------------------------------------------------------
 645                                  Driver Interface
 646    -------------------------------------------------------------------------- */
 647
 648 static int
 649 acpi_pci_link_add (
 650         struct acpi_device *device)
 651 {
 652         int                     result = 0;
 653         struct acpi_pci_link    *link = NULL;
 654         int                     i = 0;
 655         int                     found = 0;
 656
 657         ACPI_FUNCTION_TRACE("acpi_pci_link_add");
 658
 659         if (!device)
 660                 return_VALUE(-EINVAL);
 661
 662         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 663         if (!link)
 664                 return_VALUE(-ENOMEM);
 665         memset(link, 0, sizeof(struct acpi_pci_link));
 666
 667         link->device = device;
 668         link->handle = device->handle;
 669         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 670         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 671         acpi_driver_data(device) = link;
 672
 673         result = acpi_pci_link_get_possible(link);
 674         if (result)
 675                 goto end;
 676
 677         /* query and set link->irq.active */
 678         acpi_pci_link_get_current(link);
 679
 680         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 681                 acpi_device_bid(device));
 682         for (i = 0; i < link->irq.possible_count; i++) {
 683                 if (link->irq.active == link->irq.possible[i]) {
 684                         printk(" *%d", link->irq.possible[i]);
 685                         found = 1;
 686                 }
 687                 else
 688                         printk(" %d", link->irq.possible[i]);
 689         }
 690
 691         printk(")");
 692
 693         if (!found)
 694                 printk(" *%d", link->irq.active);
 695
 696         if(!link->device->status.enabled)
 697                 printk(", disabled.");
 698
 699         printk("\n");
 700
 701         /* TBD: Acquire/release lock */
 702         list_add_tail(&link->node, &acpi_link.entries);
 703         acpi_link.count++;
 704
 705 end:
 706         if (result)
 707                 kfree(link);
 708
 709         return_VALUE(result);
 710 }
 711
 712
 713 static int
 714 acpi_pci_link_remove (
 715         struct acpi_device      *device,
 716         int                     type)
 717 {
 718         struct acpi_pci_link *link = NULL;
 719
 720         ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
 721
 722         if (!device || !acpi_driver_data(device))
 723                 return_VALUE(-EINVAL);
 724
 725         link = (struct acpi_pci_link *) acpi_driver_data(device);
 726
 727         /* TBD: Acquire/release lock */
 728         list_del(&link->node);
 729
 730         kfree(link);
 731
 732         return_VALUE(0);
 733 }
 734
 735 /*
 736  * modify acpi_irq_penalty[] from cmdline
 737  */
 738 static int __init acpi_irq_penalty_update(char *str, int used)
 739 {
 740         int i;
 741
 742         for (i = 0; i < 16; i++) {
 743                 int retval;
 744                 int irq;
 745
 746                 retval = get_option(&str,&irq);
 747
 748                 if (!retval)
 749                         break;  /* no number found */
 750
 751                 if (irq < 0)
 752                         continue;
 753
 754                 if (irq >= ACPI_MAX_IRQS)
 755                         continue;
 756
 757                 if (used)
 758                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 759                 else
 760                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 761
 762                 if (retval != 2)        /* no next number */
 763                         break;
 764         }
 765         return 1;
 766 }
 767
 768 /*
 769  * Over-ride default table to reserve additional IRQs for use by ISA
 770  * e.g. acpi_irq_isa=5
 771  * Useful for telling ACPI how not to interfere with your ISA sound card.
 772  */
 773 static int __init acpi_irq_isa(char *str)
 774 {
 775         return(acpi_irq_penalty_update(str, 1));
 776 }
 777 __setup("acpi_irq_isa=", acpi_irq_isa);
 778
 779 /*
 780  * Over-ride default table to free additional IRQs for use by PCI
 781  * e.g. acpi_irq_pci=7,15
 782  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 783  */
 784 static int __init acpi_irq_pci(char *str)
 785 {
 786         return(acpi_irq_penalty_update(str, 0));
 787 }
 788 __setup("acpi_irq_pci=", acpi_irq_pci);
 789
 790 static int __init acpi_irq_nobalance_set(char *str)
 791 {
 792         acpi_irq_balance = 0;
 793         return(1);
 794 }
 795 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 796
 797 int __init acpi_irq_balance_set(char *str)
 798 {
 799         acpi_irq_balance = 1;
 800         return(1);
 801 }
 802 __setup("acpi_irq_balance", acpi_irq_balance_set);
 803
 804
 805 static int __init acpi_pci_link_init (void)
 806 {
 807         ACPI_FUNCTION_TRACE("acpi_pci_link_init");
 808
 809         if (acpi_pci_disabled)
 810                 return_VALUE(0);
 811
 812         acpi_link.count = 0;
 813         INIT_LIST_HEAD(&acpi_link.entries);
 814
 815         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 816                 return_VALUE(-ENODEV);
 817
 818         return_VALUE(0);
 819 }
 820
 821 subsys_initcall(acpi_pci_link_init);