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   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
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44
  45
  46 #define _COMPONENT              ACPI_PCI_COMPONENT
  47 ACPI_MODULE_NAME                ("pci_link")
  48
  49 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  50 #define ACPI_PCI_LINK_HID               "PNP0C0F"
  51 #define ACPI_PCI_LINK_DRIVER_NAME       "ACPI PCI Interrupt Link Driver"
  52 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  53 #define ACPI_PCI_LINK_FILE_INFO         "info"
  54 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  55
  56 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  57
  58 static int acpi_pci_link_add (struct acpi_device *device);
  59 static int acpi_pci_link_remove (struct acpi_device *device, int type);
  60
  61 static struct acpi_driver acpi_pci_link_driver = {
  62         .name =         ACPI_PCI_LINK_DRIVER_NAME,
  63         .class =        ACPI_PCI_LINK_CLASS,
  64         .ids =          ACPI_PCI_LINK_HID,
  65         .ops =          {
  66                                 .add =    acpi_pci_link_add,
  67                                 .remove = acpi_pci_link_remove,
  68                         },
  69 };
  70
  71 struct acpi_pci_link_irq {
  72         u8                      active;                 /* Current IRQ */
  73         u8                      edge_level;             /* All IRQs */
  74         u8                      active_high_low;        /* All IRQs */
  75         u8                      resource_type;
  76         u8                      possible_count;
  77         u8                      possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  78         u8                      initialized:1;
  79         u8                      suspend_resume:1;
  80         u8                      reserved:6;
  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 };
  89
  90 static struct {
  91         int                     count;
  92         struct list_head        entries;
  93 }                               acpi_link;
  94
  95
  96 /* --------------------------------------------------------------------------
  97                             PCI Link Device Management
  98    -------------------------------------------------------------------------- */
  99
 100 /*
 101  * set context (link) possible list from resource list
 102  */
 103 static acpi_status
 104 acpi_pci_link_check_possible (
 105         struct acpi_resource    *resource,
 106         void                    *context)
 107 {
 108         struct acpi_pci_link    *link = (struct acpi_pci_link *) context;
 109         u32                     i = 0;
 110
 111         ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
 112
 113         switch (resource->id) {
 114         case ACPI_RSTYPE_START_DPF:
 115                 return_ACPI_STATUS(AE_OK);
 116         case ACPI_RSTYPE_IRQ:
 117         {
 118                 struct acpi_resource_irq *p = &resource->data.irq;
 119                 if (!p || !p->number_of_interrupts) {
 120                         ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Blank IRQ resource\n"));
 121                         return_ACPI_STATUS(AE_OK);
 122                 }
 123                 for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 124                         if (!p->interrupts[i]) {
 125                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 126                                 continue;
 127                         }
 128                         link->irq.possible[i] = p->interrupts[i];
 129                         link->irq.possible_count++;
 130                 }
 131                 link->irq.edge_level = p->edge_level;
 132                 link->irq.active_high_low = p->active_high_low;
 133                 link->irq.resource_type = ACPI_RSTYPE_IRQ;
 134                 break;
 135         }
 136         case ACPI_RSTYPE_EXT_IRQ:
 137         {
 138                 struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 139                 if (!p || !p->number_of_interrupts) {
 140                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 141                                 "Blank EXT IRQ resource\n"));
 142                         return_ACPI_STATUS(AE_OK);
 143                 }
 144                 for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 145                         if (!p->interrupts[i]) {
 146                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 147                                 continue;
 148                         }
 149                         link->irq.possible[i] = p->interrupts[i];
 150                         link->irq.possible_count++;
 151                 }
 152                 link->irq.edge_level = p->edge_level;
 153                 link->irq.active_high_low = p->active_high_low;
 154                 link->irq.resource_type = ACPI_RSTYPE_EXT_IRQ;
 155                 break;
 156         }
 157         default:
 158                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 159                         "Resource is not an IRQ entry\n"));
 160                 return_ACPI_STATUS(AE_OK);
 161         }
 162
 163         return_ACPI_STATUS(AE_CTRL_TERMINATE);
 164 }
 165
 166
 167 static int
 168 acpi_pci_link_get_possible (
 169         struct acpi_pci_link    *link)
 170 {
 171         acpi_status             status;
 172
 173         ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
 174
 175         if (!link)
 176                 return_VALUE(-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_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
 182                 return_VALUE(-ENODEV);
 183         }
 184
 185         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 186                 "Found %d possible IRQs\n", link->irq.possible_count));
 187
 188         return_VALUE(0);
 189 }
 190
 191
 192 static acpi_status
 193 acpi_pci_link_check_current (
 194         struct acpi_resource    *resource,
 195         void                    *context)
 196 {
 197         int                     *irq = (int *) context;
 198
 199         ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
 200
 201         switch (resource->id) {
 202         case ACPI_RSTYPE_IRQ:
 203         {
 204                 struct acpi_resource_irq *p = &resource->data.irq;
 205                 if (!p || !p->number_of_interrupts) {
 206                         /*
 207                          * IRQ descriptors may have no IRQ# bits set,
 208                          * particularly those those w/ _STA disabled
 209                          */
 210                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 211                                 "Blank IRQ resource\n"));
 212                         return_ACPI_STATUS(AE_OK);
 213                 }
 214                 *irq = p->interrupts[0];
 215                 break;
 216         }
 217         case ACPI_RSTYPE_EXT_IRQ:
 218         {
 219                 struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 220                 if (!p || !p->number_of_interrupts) {
 221                         /*
 222                          * extended IRQ descriptors must
 223                          * return at least 1 IRQ
 224                          */
 225                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 226                                 "Blank EXT IRQ resource\n"));
 227                         return_ACPI_STATUS(AE_OK);
 228                 }
 229                 *irq = p->interrupts[0];
 230                 break;
 231         }
 232         default:
 233                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 234                         "Resource isn't an IRQ\n"));
 235                 return_ACPI_STATUS(AE_OK);
 236         }
 237         return_ACPI_STATUS(AE_CTRL_TERMINATE);
 238 }
 239
 240 /*
 241  * Run _CRS and set link->irq.active
 242  *
 243  * return value:
 244  * 0 - success
 245  * !0 - failure
 246  */
 247 static int
 248 acpi_pci_link_get_current (
 249         struct acpi_pci_link    *link)
 250 {
 251         int                     result = 0;
 252         acpi_status             status = AE_OK;
 253         int                     irq = 0;
 254
 255         ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
 256
 257         if (!link || !link->handle)
 258                 return_VALUE(-EINVAL);
 259
 260         link->irq.active = 0;
 261
 262         /* in practice, status disabled is meaningless, ignore it */
 263         if (acpi_strict) {
 264                 /* Query _STA, set link->device->status */
 265                 result = acpi_bus_get_status(link->device);
 266                 if (result) {
 267                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 268                         goto end;
 269                 }
 270
 271                 if (!link->device->status.enabled) {
 272                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 273                         return_VALUE(0);
 274                 }
 275         }
 276
 277         /*
 278          * Query and parse _CRS to get the current IRQ assignment.
 279          */
 280
 281         status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
 282                         acpi_pci_link_check_current, &irq);
 283         if (ACPI_FAILURE(status)) {
 284                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
 285                 result = -ENODEV;
 286                 goto end;
 287         }
 288
 289         if (acpi_strict && !irq) {
 290                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
 291                 result = -ENODEV;
 292         }
 293
 294         link->irq.active = irq;
 295
 296         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 297
 298 end:
 299         return_VALUE(result);
 300 }
 301
 302 static int
 303 acpi_pci_link_set (
 304         struct acpi_pci_link    *link,
 305         int                     irq)
 306 {
 307         int                     result = 0;
 308         acpi_status             status = AE_OK;
 309         struct {
 310                 struct acpi_resource    res;
 311                 struct acpi_resource    end;
 312         }    *resource;
 313         struct acpi_buffer      buffer = {0, NULL};
 314
 315         ACPI_FUNCTION_TRACE("acpi_pci_link_set");
 316
 317         if (!link || !irq)
 318                 return_VALUE(-EINVAL);
 319
 320         resource = kmalloc( sizeof(*resource)+1, GFP_KERNEL);
 321         if(!resource)
 322                 return_VALUE(-ENOMEM);
 323
 324         memset(resource, 0, sizeof(*resource)+1);
 325         buffer.length = sizeof(*resource) +1;
 326         buffer.pointer = resource;
 327
 328         switch(link->irq.resource_type) {
 329         case ACPI_RSTYPE_IRQ:
 330                 resource->res.id = ACPI_RSTYPE_IRQ;
 331                 resource->res.length = sizeof(struct acpi_resource);
 332                 resource->res.data.irq.edge_level = link->irq.edge_level;
 333                 resource->res.data.irq.active_high_low = link->irq.active_high_low;
 334                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 335                         resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 336                 else
 337                         resource->res.data.irq.shared_exclusive = ACPI_SHARED;
 338                 resource->res.data.irq.number_of_interrupts = 1;
 339                 resource->res.data.irq.interrupts[0] = irq;
 340                 break;
 341
 342         case ACPI_RSTYPE_EXT_IRQ:
 343                 resource->res.id = ACPI_RSTYPE_EXT_IRQ;
 344                 resource->res.length = sizeof(struct acpi_resource);
 345                 resource->res.data.extended_irq.producer_consumer = ACPI_CONSUMER;
 346                 resource->res.data.extended_irq.edge_level = link->irq.edge_level;
 347                 resource->res.data.extended_irq.active_high_low = link->irq.active_high_low;
 348                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 349                         resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 350                 else
 351                         resource->res.data.irq.shared_exclusive = ACPI_SHARED;
 352                 resource->res.data.extended_irq.number_of_interrupts = 1;
 353                 resource->res.data.extended_irq.interrupts[0] = irq;
 354                 /* ignore resource_source, it's optional */
 355                 break;
 356         default:
 357                 printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
 358                 result = -EINVAL;
 359                 goto end;
 360
 361         }
 362         resource->end.id = ACPI_RSTYPE_END_TAG;
 363
 364         /* Attempt to set the resource */
 365         status = acpi_set_current_resources(link->handle, &buffer);
 366
 367         /* check for total failure */
 368         if (ACPI_FAILURE(status)) {
 369                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
 370                 result = -ENODEV;
 371                 goto end;
 372         }
 373
 374         /* Query _STA, set device->status */
 375         result = acpi_bus_get_status(link->device);
 376         if (result) {
 377                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 378                 goto end;
 379         }
 380         if (!link->device->status.enabled) {
 381                 printk(KERN_WARNING PREFIX
 382                         "%s [%s] disabled and referenced, BIOS bug.\n",
 383                         acpi_device_name(link->device),
 384                         acpi_device_bid(link->device));
 385         }
 386
 387         /* Query _CRS, set link->irq.active */
 388         result = acpi_pci_link_get_current(link);
 389         if (result) {
 390                 goto end;
 391         }
 392
 393         /*
 394          * Is current setting not what we set?
 395          * set link->irq.active
 396          */
 397         if (link->irq.active != irq) {
 398                 /*
 399                  * policy: when _CRS doesn't return what we just _SRS
 400                  * assume _SRS worked and override _CRS value.
 401                  */
 402                 printk(KERN_WARNING PREFIX
 403                         "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 404                         acpi_device_name(link->device),
 405                         acpi_device_bid(link->device),
 406                         link->irq.active, irq);
 407                 link->irq.active = irq;
 408         }
 409
 410         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 411
 412 end:
 413         kfree(resource);
 414         return_VALUE(result);
 415 }
 416
 417
 418 /* --------------------------------------------------------------------------
 419                             PCI Link IRQ Management
 420    -------------------------------------------------------------------------- */
 421
 422 /*
 423  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 424  * Link Devices to move the PIRQs around to minimize sharing.
 425  *
 426  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 427  * that the BIOS has already set to active.  This is necessary because
 428  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 429  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 430  * even if acpi_irq_nobalance is set.
 431  *
 432  * A tables of penalties avoids directing PCI interrupts to well known
 433  * ISA IRQs. Boot params are available to over-ride the default table:
 434  *
 435  * List interrupts that are free for PCI use.
 436  * acpi_irq_pci=n[,m]
 437  *
 438  * List interrupts that should not be used for PCI:
 439  * acpi_irq_isa=n[,m]
 440  *
 441  * Note that PCI IRQ routers have a list of possible IRQs,
 442  * which may not include the IRQs this table says are available.
 443  *
 444  * Since this heuristic can't tell the difference between a link
 445  * that no device will attach to, vs. a link which may be shared
 446  * by multiple active devices -- it is not optimal.
 447  *
 448  * If interrupt performance is that important, get an IO-APIC system
 449  * with a pin dedicated to each device.  Or for that matter, an MSI
 450  * enabled system.
 451  */
 452
 453 #define ACPI_MAX_IRQS           256
 454 #define ACPI_MAX_ISA_IRQ        16
 455
 456 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 457 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 458 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 459 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 460 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 461 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 462
 463 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 464         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 465         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 466         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 467         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 468         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 469         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 470         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 471         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 472         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 473         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 474         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 475         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 476         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 477         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 478         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 479         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 480                         /* >IRQ15 */
 481 };
 482
 483 int __init
 484 acpi_irq_penalty_init(void)
 485 {
 486         struct list_head        *node = NULL;
 487         struct acpi_pci_link    *link = NULL;
 488         int                     i = 0;
 489
 490         ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");
 491
 492         /*
 493          * Update penalties to facilitate IRQ balancing.
 494          */
 495         list_for_each(node, &acpi_link.entries) {
 496
 497                 link = list_entry(node, struct acpi_pci_link, node);
 498                 if (!link) {
 499                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 500                         continue;
 501                 }
 502
 503                 /*
 504                  * reflect the possible and active irqs in the penalty table --
 505                  * useful for breaking ties.
 506                  */
 507                 if (link->irq.possible_count) {
 508                         int penalty = PIRQ_PENALTY_PCI_POSSIBLE / link->irq.possible_count;
 509
 510                         for (i = 0; i < link->irq.possible_count; i++) {
 511                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 512                                         acpi_irq_penalty[link->irq.possible[i]] += penalty;
 513                         }
 514
 515                 } else if (link->irq.active) {
 516                         acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_POSSIBLE;
 517                 }
 518         }
 519         /* Add a penalty for the SCI */
 520         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 521
 522         return_VALUE(0);
 523 }
 524
 525 static int acpi_irq_balance;    /* 0: static, 1: balance */
 526
 527 static int acpi_pci_link_allocate(
 528         struct acpi_pci_link    *link)
 529 {
 530         int                     irq;
 531         int                     i;
 532
 533         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 534
 535         if (link->irq.suspend_resume) {
 536                 acpi_pci_link_set(link, link->irq.active);
 537                 link->irq.suspend_resume = 0;
 538         }
 539         if (link->irq.initialized)
 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.initialized = 1;
 594
 595         return_VALUE(0);
 596 }
 597
 598 /*
 599  * acpi_pci_link_get_irq
 600  * success: return IRQ >= 0
 601  * failure: return -1
 602  */
 603
 604 int
 605 acpi_pci_link_get_irq (
 606         acpi_handle             handle,
 607         int                     index,
 608         int                     *edge_level,
 609         int                     *active_high_low,
 610         char                    **name)
 611 {
 612         int                     result = 0;
 613         struct acpi_device      *device = NULL;
 614         struct acpi_pci_link    *link = NULL;
 615
 616         ACPI_FUNCTION_TRACE("acpi_pci_link_get_irq");
 617
 618         result = acpi_bus_get_device(handle, &device);
 619         if (result) {
 620                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 621                 return_VALUE(-1);
 622         }
 623
 624         link = (struct acpi_pci_link *) acpi_driver_data(device);
 625         if (!link) {
 626                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 627                 return_VALUE(-1);
 628         }
 629
 630         /* TBD: Support multiple index (IRQ) entries per Link Device */
 631         if (index) {
 632                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
 633                 return_VALUE(-1);
 634         }
 635
 636         if (acpi_pci_link_allocate(link))
 637                 return_VALUE(-1);
 638
 639         if (!link->irq.active) {
 640                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
 641                 return_VALUE(-1);
 642         }
 643
 644         if (edge_level) *edge_level = link->irq.edge_level;
 645         if (active_high_low) *active_high_low = link->irq.active_high_low;
 646         if (name) *name = acpi_device_bid(link->device);
 647         return_VALUE(link->irq.active);
 648 }
 649
 650
 651 /* --------------------------------------------------------------------------
 652                                  Driver Interface
 653    -------------------------------------------------------------------------- */
 654
 655 static int
 656 acpi_pci_link_add (
 657         struct acpi_device *device)
 658 {
 659         int                     result = 0;
 660         struct acpi_pci_link    *link = NULL;
 661         int                     i = 0;
 662         int                     found = 0;
 663
 664         ACPI_FUNCTION_TRACE("acpi_pci_link_add");
 665
 666         if (!device)
 667                 return_VALUE(-EINVAL);
 668
 669         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 670         if (!link)
 671                 return_VALUE(-ENOMEM);
 672         memset(link, 0, sizeof(struct acpi_pci_link));
 673
 674         link->device = device;
 675         link->handle = device->handle;
 676         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 677         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 678         acpi_driver_data(device) = link;
 679
 680         result = acpi_pci_link_get_possible(link);
 681         if (result)
 682                 goto end;
 683
 684         /* query and set link->irq.active */
 685         acpi_pci_link_get_current(link);
 686
 687         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 688                 acpi_device_bid(device));
 689         for (i = 0; i < link->irq.possible_count; i++) {
 690                 if (link->irq.active == link->irq.possible[i]) {
 691                         printk(" *%d", link->irq.possible[i]);
 692                         found = 1;
 693                 }
 694                 else
 695                         printk(" %d", link->irq.possible[i]);
 696         }
 697
 698         printk(")");
 699
 700         if (!found)
 701                 printk(" *%d", link->irq.active);
 702
 703         if(!link->device->status.enabled)
 704                 printk(", disabled.");
 705
 706         printk("\n");
 707
 708         /* TBD: Acquire/release lock */
 709         list_add_tail(&link->node, &acpi_link.entries);
 710         acpi_link.count++;
 711
 712 end:
 713         /* disable all links -- to be activated on use */
 714         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 715
 716         if (result)
 717                 kfree(link);
 718
 719         return_VALUE(result);
 720 }
 721
 722 static int
 723 irqrouter_suspend(
 724         struct sys_device *dev,
 725         u32     state)
 726 {
 727         struct list_head        *node = NULL;
 728         struct acpi_pci_link    *link = NULL;
 729
 730         ACPI_FUNCTION_TRACE("irqrouter_suspend");
 731
 732         list_for_each(node, &acpi_link.entries) {
 733                 link = list_entry(node, struct acpi_pci_link, node);
 734                 if (!link) {
 735                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 736                         continue;
 737                 }
 738                 if (link->irq.active && link->irq.initialized)
 739                         link->irq.suspend_resume = 1;
 740         }
 741         return_VALUE(0);
 742 }
 743
 744
 745 static int
 746 acpi_pci_link_remove (
 747         struct acpi_device      *device,
 748         int                     type)
 749 {
 750         struct acpi_pci_link *link = NULL;
 751
 752         ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
 753
 754         if (!device || !acpi_driver_data(device))
 755                 return_VALUE(-EINVAL);
 756
 757         link = (struct acpi_pci_link *) acpi_driver_data(device);
 758
 759         /* TBD: Acquire/release lock */
 760         list_del(&link->node);
 761
 762         kfree(link);
 763
 764         return_VALUE(0);
 765 }
 766
 767 /*
 768  * modify acpi_irq_penalty[] from cmdline
 769  */
 770 static int __init acpi_irq_penalty_update(char *str, int used)
 771 {
 772         int i;
 773
 774         for (i = 0; i < 16; i++) {
 775                 int retval;
 776                 int irq;
 777
 778                 retval = get_option(&str,&irq);
 779
 780                 if (!retval)
 781                         break;  /* no number found */
 782
 783                 if (irq < 0)
 784                         continue;
 785
 786                 if (irq >= ACPI_MAX_IRQS)
 787                         continue;
 788
 789                 if (used)
 790                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 791                 else
 792                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 793
 794                 if (retval != 2)        /* no next number */
 795                         break;
 796         }
 797         return 1;
 798 }
 799
 800 /*
 801  * We'd like PNP to call this routine for the
 802  * single ISA_USED value for each legacy device.
 803  * But instead it calls us with each POSSIBLE setting.
 804  * There is no ISA_POSSIBLE weight, so we simply use
 805  * the (small) PCI_USING penalty.
 806  */
 807 void acpi_penalize_isa_irq(int irq, int active)
 808 {
 809         if (active)
 810                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 811         else
 812                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 813 }
 814
 815 /*
 816  * Over-ride default table to reserve additional IRQs for use by ISA
 817  * e.g. acpi_irq_isa=5
 818  * Useful for telling ACPI how not to interfere with your ISA sound card.
 819  */
 820 static int __init acpi_irq_isa(char *str)
 821 {
 822         return acpi_irq_penalty_update(str, 1);
 823 }
 824 __setup("acpi_irq_isa=", acpi_irq_isa);
 825
 826 /*
 827  * Over-ride default table to free additional IRQs for use by PCI
 828  * e.g. acpi_irq_pci=7,15
 829  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 830  */
 831 static int __init acpi_irq_pci(char *str)
 832 {
 833         return acpi_irq_penalty_update(str, 0);
 834 }
 835 __setup("acpi_irq_pci=", acpi_irq_pci);
 836
 837 static int __init acpi_irq_nobalance_set(char *str)
 838 {
 839         acpi_irq_balance = 0;
 840         return 1;
 841 }
 842 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 843
 844 int __init acpi_irq_balance_set(char *str)
 845 {
 846         acpi_irq_balance = 1;
 847         return 1;
 848 }
 849 __setup("acpi_irq_balance", acpi_irq_balance_set);
 850
 851
 852 static struct sysdev_class irqrouter_sysdev_class = {
 853         set_kset_name("irqrouter"),
 854         .suspend = irqrouter_suspend,
 855 };
 856
 857
 858 static struct sys_device device_irqrouter = {
 859         .id     = 0,
 860         .cls    = &irqrouter_sysdev_class,
 861 };
 862
 863
 864 static int __init irqrouter_init_sysfs(void)
 865 {
 866         int error;
 867
 868         ACPI_FUNCTION_TRACE("irqrouter_init_sysfs");
 869
 870         if (acpi_disabled || acpi_noirq)
 871                 return_VALUE(0);
 872
 873         error = sysdev_class_register(&irqrouter_sysdev_class);
 874         if (!error)
 875                 error = sysdev_register(&device_irqrouter);
 876
 877         return_VALUE(error);
 878 }
 879
 880 device_initcall(irqrouter_init_sysfs);
 881
 882
 883 static int __init acpi_pci_link_init (void)
 884 {
 885         ACPI_FUNCTION_TRACE("acpi_pci_link_init");
 886
 887         if (acpi_noirq)
 888                 return_VALUE(0);
 889
 890         acpi_link.count = 0;
 891         INIT_LIST_HEAD(&acpi_link.entries);
 892
 893         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 894                 return_VALUE(-ENODEV);
 895
 896         return_VALUE(0);
 897 }
 898
 899 subsys_initcall(acpi_pci_link_init);