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
 312         ACPI_FUNCTION_TRACE("acpi_pci_link_set");
 313
 314         if (!link || !irq)
 315                 return_VALUE(-EINVAL);
 316
 317         memset(&resource, 0, sizeof(resource));
 318
 319         switch(link->irq.resource_type) {
 320         case ACPI_RSTYPE_IRQ:
 321                 resource.res.id = ACPI_RSTYPE_IRQ;
 322                 resource.res.length = sizeof(struct acpi_resource);
 323                 resource.res.data.irq.edge_level = link->irq.edge_level;
 324                 resource.res.data.irq.active_high_low = link->irq.active_high_low;
 325                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 326                         resource.res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 327                 else
 328                         resource.res.data.irq.shared_exclusive = ACPI_SHARED;
 329                 resource.res.data.irq.number_of_interrupts = 1;
 330                 resource.res.data.irq.interrupts[0] = irq;
 331                 break;
 332
 333         case ACPI_RSTYPE_EXT_IRQ:
 334                 resource.res.id = ACPI_RSTYPE_EXT_IRQ;
 335                 resource.res.length = sizeof(struct acpi_resource);
 336                 resource.res.data.extended_irq.producer_consumer = ACPI_CONSUMER;
 337                 resource.res.data.extended_irq.edge_level = link->irq.edge_level;
 338                 resource.res.data.extended_irq.active_high_low = link->irq.active_high_low;
 339                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 340                         resource.res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 341                 else
 342                         resource.res.data.irq.shared_exclusive = ACPI_SHARED;
 343                 resource.res.data.extended_irq.number_of_interrupts = 1;
 344                 resource.res.data.extended_irq.interrupts[0] = irq;
 345                 /* ignore resource_source, it's optional */
 346                 break;
 347         default:
 348                 printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
 349                 return_VALUE(-EINVAL);
 350
 351         }
 352         resource.end.id = ACPI_RSTYPE_END_TAG;
 353
 354         /* Attempt to set the resource */
 355         status = acpi_set_current_resources(link->handle, &buffer);
 356
 357         /* check for total failure */
 358         if (ACPI_FAILURE(status)) {
 359                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
 360                 return_VALUE(-ENODEV);
 361         }
 362
 363         /* Query _STA, set device->status */
 364         result = acpi_bus_get_status(link->device);
 365         if (result) {
 366                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 367                 return_VALUE(result);
 368         }
 369         if (!link->device->status.enabled) {
 370                 printk(KERN_WARNING PREFIX
 371                         "%s [%s] disabled and referenced, BIOS bug.\n",
 372                         acpi_device_name(link->device),
 373                         acpi_device_bid(link->device));
 374         }
 375
 376         /* Query _CRS, set link->irq.active */
 377         result = acpi_pci_link_get_current(link);
 378         if (result) {
 379                 return_VALUE(result);
 380         }
 381
 382         /*
 383          * Is current setting not what we set?
 384          * set link->irq.active
 385          */
 386         if (link->irq.active != irq) {
 387                 /*
 388                  * policy: when _CRS doesn't return what we just _SRS
 389                  * assume _SRS worked and override _CRS value.
 390                  */
 391                 printk(KERN_WARNING PREFIX
 392                         "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 393                         acpi_device_name(link->device),
 394                         acpi_device_bid(link->device),
 395                         link->irq.active, irq);
 396                 link->irq.active = irq;
 397         }
 398
 399         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 400
 401         return_VALUE(0);
 402 }
 403
 404
 405 /* --------------------------------------------------------------------------
 406                             PCI Link IRQ Management
 407    -------------------------------------------------------------------------- */
 408
 409 /*
 410  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 411  * Link Devices to move the PIRQs around to minimize sharing.
 412  *
 413  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 414  * that the BIOS has already set to active.  This is necessary because
 415  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 416  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 417  * even if acpi_irq_nobalance is set.
 418  *
 419  * A tables of penalties avoids directing PCI interrupts to well known
 420  * ISA IRQs. Boot params are available to over-ride the default table:
 421  *
 422  * List interrupts that are free for PCI use.
 423  * acpi_irq_pci=n[,m]
 424  *
 425  * List interrupts that should not be used for PCI:
 426  * acpi_irq_isa=n[,m]
 427  *
 428  * Note that PCI IRQ routers have a list of possible IRQs,
 429  * which may not include the IRQs this table says are available.
 430  *
 431  * Since this heuristic can't tell the difference between a link
 432  * that no device will attach to, vs. a link which may be shared
 433  * by multiple active devices -- it is not optimal.
 434  *
 435  * If interrupt performance is that important, get an IO-APIC system
 436  * with a pin dedicated to each device.  Or for that matter, an MSI
 437  * enabled system.
 438  */
 439
 440 #define ACPI_MAX_IRQS           256
 441 #define ACPI_MAX_ISA_IRQ        16
 442
 443 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 444 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 445 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 446 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 447 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 448 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 449
 450 static int __initdata acpi_irq_penalty[ACPI_MAX_IRQS] = {
 451         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 452         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 453         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 454         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 455         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 456         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 457         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 458         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 459         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 460         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 461         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 462         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 463         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 464         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 465         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 466         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 467                         /* >IRQ15 */
 468 };
 469
 470 int
 471 acpi_irq_penalty_init(void)
 472 {
 473         struct list_head        *node = NULL;
 474         struct acpi_pci_link    *link = NULL;
 475         int                     i = 0;
 476
 477         ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");
 478
 479         /*
 480          * Update penalties to facilitate IRQ balancing.
 481          */
 482         list_for_each(node, &acpi_link.entries) {
 483
 484                 link = list_entry(node, struct acpi_pci_link, node);
 485                 if (!link) {
 486                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 487                         continue;
 488                 }
 489
 490                 /*
 491                  * reflect the possible and active irqs in the penalty table --
 492                  * useful for breaking ties.
 493                  */
 494                 if (link->irq.possible_count) {
 495                         int penalty = PIRQ_PENALTY_PCI_POSSIBLE / link->irq.possible_count;
 496
 497                         for (i = 0; i < link->irq.possible_count; i++) {
 498                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 499                                         acpi_irq_penalty[link->irq.possible[i]] += penalty;
 500                         }
 501
 502                 } else if (link->irq.active) {
 503                         acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_POSSIBLE;
 504                 }
 505         }
 506         /* Add a penalty for the SCI */
 507         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 508
 509         return_VALUE(0);
 510 }
 511
 512 static int acpi_irq_balance;    /* 0: static, 1: balance */
 513
 514 static int acpi_pci_link_allocate(struct acpi_pci_link* link) {
 515         int irq;
 516         int i;
 517
 518         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 519
 520         if (link->irq.setonboot)
 521                 return_VALUE(0);
 522
 523         /*
 524          * search for active IRQ in list of possible IRQs.
 525          */
 526         for (i = 0; i < link->irq.possible_count; ++i) {
 527                 if (link->irq.active == link->irq.possible[i])
 528                         break;
 529         }
 530         /*
 531          * forget active IRQ that is not in possible list
 532          */
 533         if (i == link->irq.possible_count) {
 534                 if (acpi_strict)
 535                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 536                                 " in _PRS\n", link->irq.active);
 537                 link->irq.active = 0;
 538         }
 539
 540         /*
 541          * if active found, use it; else pick entry from end of possible list.
 542          */
 543         if (link->irq.active) {
 544                 irq = link->irq.active;
 545         } else {
 546                 irq = link->irq.possible[link->irq.possible_count - 1];
 547         }
 548
 549         if (acpi_irq_balance || !link->irq.active) {
 550                 /*
 551                  * Select the best IRQ.  This is done in reverse to promote
 552                  * the use of IRQs 9, 10, 11, and >15.
 553                  */
 554                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 555                         if (acpi_irq_penalty[irq] > acpi_irq_penalty[link->irq.possible[i]])
 556                                 irq = link->irq.possible[i];
 557                 }
 558         }
 559
 560         /* Attempt to enable the link device at this IRQ. */
 561         if (acpi_pci_link_set(link, irq)) {
 562                 printk(PREFIX "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
 563                                 "Try pci=noacpi or acpi=off\n",
 564                         acpi_device_name(link->device),
 565                         acpi_device_bid(link->device));
 566                 return_VALUE(-ENODEV);
 567         } else {
 568                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 569                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 570                         acpi_device_name(link->device),
 571                         acpi_device_bid(link->device), link->irq.active);
 572         }
 573
 574         link->irq.setonboot = 1;
 575
 576         return_VALUE(0);
 577 }
 578
 579
 580 int
 581 acpi_pci_link_get_irq (
 582         acpi_handle             handle,
 583         int                     index,
 584         int*                    edge_level,
 585         int*                    active_high_low)
 586 {
 587         int                     result = 0;
 588         struct acpi_device      *device = NULL;
 589         struct acpi_pci_link    *link = NULL;
 590
 591         ACPI_FUNCTION_TRACE("acpi_pci_link_get_irq");
 592
 593         result = acpi_bus_get_device(handle, &device);
 594         if (result) {
 595                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 596                 return_VALUE(0);
 597         }
 598
 599         link = (struct acpi_pci_link *) acpi_driver_data(device);
 600         if (!link) {
 601                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 602                 return_VALUE(0);
 603         }
 604
 605         /* TBD: Support multiple index (IRQ) entries per Link Device */
 606         if (index) {
 607                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
 608                 return_VALUE(0);
 609         }
 610
 611         if (acpi_pci_link_allocate(link))
 612                 return_VALUE(0);
 613
 614         if (!link->irq.active) {
 615                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
 616                 return_VALUE(0);
 617         }
 618
 619         if (edge_level) *edge_level = link->irq.edge_level;
 620         if (active_high_low) *active_high_low = link->irq.active_high_low;
 621         return_VALUE(link->irq.active);
 622 }
 623
 624
 625 /* --------------------------------------------------------------------------
 626                                  Driver Interface
 627    -------------------------------------------------------------------------- */
 628
 629 static int
 630 acpi_pci_link_add (
 631         struct acpi_device *device)
 632 {
 633         int                     result = 0;
 634         struct acpi_pci_link    *link = NULL;
 635         int                     i = 0;
 636         int                     found = 0;
 637
 638         ACPI_FUNCTION_TRACE("acpi_pci_link_add");
 639
 640         if (!device)
 641                 return_VALUE(-EINVAL);
 642
 643         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 644         if (!link)
 645                 return_VALUE(-ENOMEM);
 646         memset(link, 0, sizeof(struct acpi_pci_link));
 647
 648         link->device = device;
 649         link->handle = device->handle;
 650         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 651         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 652         acpi_driver_data(device) = link;
 653
 654         result = acpi_pci_link_get_possible(link);
 655         if (result)
 656                 goto end;
 657
 658         /* query and set link->irq.active */
 659         acpi_pci_link_get_current(link);
 660
 661         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 662                 acpi_device_bid(device));
 663         for (i = 0; i < link->irq.possible_count; i++) {
 664                 if (link->irq.active == link->irq.possible[i]) {
 665                         printk(" *%d", link->irq.possible[i]);
 666                         found = 1;
 667                 }
 668                 else
 669                         printk(" %d", link->irq.possible[i]);
 670         }
 671
 672         printk(")");
 673
 674         if (!found)
 675                 printk(" *%d", link->irq.active);
 676
 677         if(!link->device->status.enabled)
 678                 printk(", disabled.");
 679
 680         printk("\n");
 681
 682         /* TBD: Acquire/release lock */
 683         list_add_tail(&link->node, &acpi_link.entries);
 684         acpi_link.count++;
 685
 686 end:
 687         /* disable all links -- to be activated on use */
 688         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 689
 690         if (result)
 691                 kfree(link);
 692
 693         return_VALUE(result);
 694 }
 695
 696
 697 static int
 698 acpi_pci_link_remove (
 699         struct acpi_device      *device,
 700         int                     type)
 701 {
 702         struct acpi_pci_link *link = NULL;
 703
 704         ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
 705
 706         if (!device || !acpi_driver_data(device))
 707                 return_VALUE(-EINVAL);
 708
 709         link = (struct acpi_pci_link *) acpi_driver_data(device);
 710
 711         /* TBD: Acquire/release lock */
 712         list_del(&link->node);
 713
 714         kfree(link);
 715
 716         return_VALUE(0);
 717 }
 718
 719 /*
 720  * modify acpi_irq_penalty[] from cmdline
 721  */
 722 static int __init acpi_irq_penalty_update(char *str, int used)
 723 {
 724         int i;
 725
 726         for (i = 0; i < 16; i++) {
 727                 int retval;
 728                 int irq;
 729
 730                 retval = get_option(&str,&irq);
 731
 732                 if (!retval)
 733                         break;  /* no number found */
 734
 735                 if (irq < 0)
 736                         continue;
 737
 738                 if (irq >= ACPI_MAX_IRQS)
 739                         continue;
 740
 741                 if (used)
 742                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 743                 else
 744                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 745
 746                 if (retval != 2)        /* no next number */
 747                         break;
 748         }
 749         return 1;
 750 }
 751
 752 /*
 753  * Over-ride default table to reserve additional IRQs for use by ISA
 754  * e.g. acpi_irq_isa=5
 755  * Useful for telling ACPI how not to interfere with your ISA sound card.
 756  */
 757 static int __init acpi_irq_isa(char *str)
 758 {
 759         return(acpi_irq_penalty_update(str, 1));
 760 }
 761 __setup("acpi_irq_isa=", acpi_irq_isa);
 762
 763 /*
 764  * Over-ride default table to free additional IRQs for use by PCI
 765  * e.g. acpi_irq_pci=7,15
 766  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 767  */
 768 static int __init acpi_irq_pci(char *str)
 769 {
 770         return(acpi_irq_penalty_update(str, 0));
 771 }
 772 __setup("acpi_irq_pci=", acpi_irq_pci);
 773
 774 static int __init acpi_irq_nobalance_set(char *str)
 775 {
 776         acpi_irq_balance = 0;
 777         return(1);
 778 }
 779 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 780
 781 int __init acpi_irq_balance_set(char *str)
 782 {
 783         acpi_irq_balance = 1;
 784         return(1);
 785 }
 786 __setup("acpi_irq_balance", acpi_irq_balance_set);
 787
 788
 789 static int __init acpi_pci_link_init (void)
 790 {
 791         ACPI_FUNCTION_TRACE("acpi_pci_link_init");
 792
 793         if (acpi_pci_disabled)
 794                 return_VALUE(0);
 795
 796         acpi_link.count = 0;
 797         INIT_LIST_HEAD(&acpi_link.entries);
 798
 799         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 800                 return_VALUE(-ENODEV);
 801
 802         return_VALUE(0);
 803 }
 804
 805 subsys_initcall(acpi_pci_link_init);