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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 #include <linux/mutex.h>
  42
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45
  46 #define _COMPONENT              ACPI_PCI_COMPONENT
  47 ACPI_MODULE_NAME("pci_link");
  48 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  49 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  50 #define ACPI_PCI_LINK_FILE_INFO         "info"
  51 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  52 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  53 static int acpi_pci_link_add(struct acpi_device *device);
  54 static int acpi_pci_link_remove(struct acpi_device *device, int type);
  55
  56 static struct acpi_device_id link_device_ids[] = {
  57         {"PNP0C0F", 0},
  58         {"", 0},
  59 };
  60 MODULE_DEVICE_TABLE(acpi, link_device_ids);
  61
  62 static struct acpi_driver acpi_pci_link_driver = {
  63         .name = "pci_link",
  64         .class = ACPI_PCI_LINK_CLASS,
  65         .ids = link_device_ids,
  66         .ops = {
  67                 .add = acpi_pci_link_add,
  68                 .remove = acpi_pci_link_remove,
  69                 },
  70 };
  71
  72 /*
  73  * If a link is initialized, we never change its active and initialized
  74  * later even the link is disable. Instead, we just repick the active irq
  75  */
  76 struct acpi_pci_link_irq {
  77         u8 active;              /* Current IRQ */
  78         u8 triggering;          /* All IRQs */
  79         u8 polarity;    /* All IRQs */
  80         u8 resource_type;
  81         u8 possible_count;
  82         u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  83         u8 initialized:1;
  84         u8 reserved:7;
  85 };
  86
  87 struct acpi_pci_link {
  88         struct list_head node;
  89         struct acpi_device *device;
  90         struct acpi_pci_link_irq irq;
  91         int refcnt;
  92 };
  93
  94 static struct {
  95         int count;
  96         struct list_head entries;
  97 } acpi_link;
  98 static DEFINE_MUTEX(acpi_link_lock);
  99
 100 /* --------------------------------------------------------------------------
 101                             PCI Link Device Management
 102    -------------------------------------------------------------------------- */
 103
 104 /*
 105  * set context (link) possible list from resource list
 106  */
 107 static acpi_status
 108 acpi_pci_link_check_possible(struct acpi_resource *resource, void *context)
 109 {
 110         struct acpi_pci_link *link = context;
 111         u32 i = 0;
 112
 113
 114         switch (resource->type) {
 115         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 116         case ACPI_RESOURCE_TYPE_END_TAG:
 117                 return AE_OK;
 118         case ACPI_RESOURCE_TYPE_IRQ:
 119                 {
 120                         struct acpi_resource_irq *p = &resource->data.irq;
 121                         if (!p || !p->interrupt_count) {
 122                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 123                                                   "Blank _PRS IRQ resource\n"));
 124                                 return AE_OK;
 125                         }
 126                         for (i = 0;
 127                              (i < p->interrupt_count
 128                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 129                                 if (!p->interrupts[i]) {
 130                                         printk(KERN_WARNING PREFIX
 131                                                "Invalid _PRS IRQ %d\n",
 132                                                p->interrupts[i]);
 133                                         continue;
 134                                 }
 135                                 link->irq.possible[i] = p->interrupts[i];
 136                                 link->irq.possible_count++;
 137                         }
 138                         link->irq.triggering = p->triggering;
 139                         link->irq.polarity = p->polarity;
 140                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 141                         break;
 142                 }
 143         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 144                 {
 145                         struct acpi_resource_extended_irq *p =
 146                             &resource->data.extended_irq;
 147                         if (!p || !p->interrupt_count) {
 148                                 printk(KERN_WARNING PREFIX
 149                                               "Blank _PRS EXT IRQ resource\n");
 150                                 return AE_OK;
 151                         }
 152                         for (i = 0;
 153                              (i < p->interrupt_count
 154                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 155                                 if (!p->interrupts[i]) {
 156                                         printk(KERN_WARNING PREFIX
 157                                                "Invalid _PRS IRQ %d\n",
 158                                                p->interrupts[i]);
 159                                         continue;
 160                                 }
 161                                 link->irq.possible[i] = p->interrupts[i];
 162                                 link->irq.possible_count++;
 163                         }
 164                         link->irq.triggering = p->triggering;
 165                         link->irq.polarity = p->polarity;
 166                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 167                         break;
 168                 }
 169         default:
 170                 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 171                        resource->type);
 172                 return AE_OK;
 173         }
 174
 175         return AE_CTRL_TERMINATE;
 176 }
 177
 178 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 179 {
 180         acpi_status status;
 181
 182
 183         if (!link)
 184                 return -EINVAL;
 185
 186         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 187                                      acpi_pci_link_check_possible, link);
 188         if (ACPI_FAILURE(status)) {
 189                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRS"));
 190                 return -ENODEV;
 191         }
 192
 193         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 194                           "Found %d possible IRQs\n",
 195                           link->irq.possible_count));
 196
 197         return 0;
 198 }
 199
 200 static acpi_status
 201 acpi_pci_link_check_current(struct acpi_resource *resource, void *context)
 202 {
 203         int *irq = (int *)context;
 204
 205
 206         switch (resource->type) {
 207         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 208         case ACPI_RESOURCE_TYPE_END_TAG:
 209                 return AE_OK;
 210         case ACPI_RESOURCE_TYPE_IRQ:
 211                 {
 212                         struct acpi_resource_irq *p = &resource->data.irq;
 213                         if (!p || !p->interrupt_count) {
 214                                 /*
 215                                  * IRQ descriptors may have no IRQ# bits set,
 216                                  * particularly those those w/ _STA disabled
 217                                  */
 218                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 219                                                   "Blank _CRS IRQ resource\n"));
 220                                 return AE_OK;
 221                         }
 222                         *irq = p->interrupts[0];
 223                         break;
 224                 }
 225         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 226                 {
 227                         struct acpi_resource_extended_irq *p =
 228                             &resource->data.extended_irq;
 229                         if (!p || !p->interrupt_count) {
 230                                 /*
 231                                  * extended IRQ descriptors must
 232                                  * return at least 1 IRQ
 233                                  */
 234                                 printk(KERN_WARNING PREFIX
 235                                               "Blank _CRS EXT IRQ resource\n");
 236                                 return AE_OK;
 237                         }
 238                         *irq = p->interrupts[0];
 239                         break;
 240                 }
 241                 break;
 242         default:
 243                 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 244                        resource->type);
 245                 return AE_OK;
 246         }
 247
 248         return AE_CTRL_TERMINATE;
 249 }
 250
 251 /*
 252  * Run _CRS and set link->irq.active
 253  *
 254  * return value:
 255  * 0 - success
 256  * !0 - failure
 257  */
 258 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 259 {
 260         int result = 0;
 261         acpi_status status = AE_OK;
 262         int irq = 0;
 263
 264         if (!link)
 265                 return -EINVAL;
 266
 267         link->irq.active = 0;
 268
 269         /* in practice, status disabled is meaningless, ignore it */
 270         if (acpi_strict) {
 271                 /* Query _STA, set link->device->status */
 272                 result = acpi_bus_get_status(link->device);
 273                 if (result) {
 274                         printk(KERN_ERR PREFIX "Unable to read status\n");
 275                         goto end;
 276                 }
 277
 278                 if (!link->device->status.enabled) {
 279                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 280                         return 0;
 281                 }
 282         }
 283
 284         /*
 285          * Query and parse _CRS to get the current IRQ assignment.
 286          */
 287
 288         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 289                                      acpi_pci_link_check_current, &irq);
 290         if (ACPI_FAILURE(status)) {
 291                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 292                 result = -ENODEV;
 293                 goto end;
 294         }
 295
 296         if (acpi_strict && !irq) {
 297                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 298                 result = -ENODEV;
 299         }
 300
 301         link->irq.active = irq;
 302
 303         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 304
 305       end:
 306         return result;
 307 }
 308
 309 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 310 {
 311         int result = 0;
 312         acpi_status status = AE_OK;
 313         struct {
 314                 struct acpi_resource res;
 315                 struct acpi_resource end;
 316         } *resource;
 317         struct acpi_buffer buffer = { 0, NULL };
 318
 319
 320         if (!link || !irq)
 321                 return -EINVAL;
 322
 323         resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 324         if (!resource)
 325                 return -ENOMEM;
 326
 327         buffer.length = sizeof(*resource) + 1;
 328         buffer.pointer = resource;
 329
 330         switch (link->irq.resource_type) {
 331         case ACPI_RESOURCE_TYPE_IRQ:
 332                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 333                 resource->res.length = sizeof(struct acpi_resource);
 334                 resource->res.data.irq.triggering = link->irq.triggering;
 335                 resource->res.data.irq.polarity =
 336                     link->irq.polarity;
 337                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 338                         resource->res.data.irq.sharable =
 339                             ACPI_EXCLUSIVE;
 340                 else
 341                         resource->res.data.irq.sharable = ACPI_SHARED;
 342                 resource->res.data.irq.interrupt_count = 1;
 343                 resource->res.data.irq.interrupts[0] = irq;
 344                 break;
 345
 346         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 347                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 348                 resource->res.length = sizeof(struct acpi_resource);
 349                 resource->res.data.extended_irq.producer_consumer =
 350                     ACPI_CONSUMER;
 351                 resource->res.data.extended_irq.triggering =
 352                     link->irq.triggering;
 353                 resource->res.data.extended_irq.polarity =
 354                     link->irq.polarity;
 355                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 356                         resource->res.data.irq.sharable =
 357                             ACPI_EXCLUSIVE;
 358                 else
 359                         resource->res.data.irq.sharable = ACPI_SHARED;
 360                 resource->res.data.extended_irq.interrupt_count = 1;
 361                 resource->res.data.extended_irq.interrupts[0] = irq;
 362                 /* ignore resource_source, it's optional */
 363                 break;
 364         default:
 365                 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 366                 result = -EINVAL;
 367                 goto end;
 368
 369         }
 370         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 371
 372         /* Attempt to set the resource */
 373         status = acpi_set_current_resources(link->device->handle, &buffer);
 374
 375         /* check for total failure */
 376         if (ACPI_FAILURE(status)) {
 377                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 378                 result = -ENODEV;
 379                 goto end;
 380         }
 381
 382         /* Query _STA, set device->status */
 383         result = acpi_bus_get_status(link->device);
 384         if (result) {
 385                 printk(KERN_ERR PREFIX "Unable to read status\n");
 386                 goto end;
 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                 goto end;
 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), link->irq.active, irq);
 414                 link->irq.active = irq;
 415         }
 416
 417         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 418
 419       end:
 420         kfree(resource);
 421         return result;
 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 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 __init acpi_irq_penalty_init(void)
 490 {
 491         struct list_head *node = NULL;
 492         struct acpi_pci_link *link = NULL;
 493         int i = 0;
 494
 495
 496         /*
 497          * Update penalties to facilitate IRQ balancing.
 498          */
 499         list_for_each(node, &acpi_link.entries) {
 500
 501                 link = list_entry(node, struct acpi_pci_link, node);
 502                 if (!link) {
 503                         printk(KERN_ERR PREFIX "Invalid link context\n");
 504                         continue;
 505                 }
 506
 507                 /*
 508                  * reflect the possible and active irqs in the penalty table --
 509                  * useful for breaking ties.
 510                  */
 511                 if (link->irq.possible_count) {
 512                         int penalty =
 513                             PIRQ_PENALTY_PCI_POSSIBLE /
 514                             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.
 519                                                          possible[i]] +=
 520                                             penalty;
 521                         }
 522
 523                 } else if (link->irq.active) {
 524                         acpi_irq_penalty[link->irq.active] +=
 525                             PIRQ_PENALTY_PCI_POSSIBLE;
 526                 }
 527         }
 528         /* Add a penalty for the SCI */
 529         acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;
 530
 531         return 0;
 532 }
 533
 534 static int acpi_irq_balance;    /* 0: static, 1: balance */
 535
 536 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 537 {
 538         int irq;
 539         int i;
 540
 541
 542         if (link->irq.initialized) {
 543                 if (link->refcnt == 0)
 544                         /* This means the link is disabled but initialized */
 545                         acpi_pci_link_set(link, link->irq.active);
 546                 return 0;
 547         }
 548
 549         /*
 550          * search for active IRQ in list of possible IRQs.
 551          */
 552         for (i = 0; i < link->irq.possible_count; ++i) {
 553                 if (link->irq.active == link->irq.possible[i])
 554                         break;
 555         }
 556         /*
 557          * forget active IRQ that is not in possible list
 558          */
 559         if (i == link->irq.possible_count) {
 560                 if (acpi_strict)
 561                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 562                                       " in _PRS\n", link->irq.active);
 563                 link->irq.active = 0;
 564         }
 565
 566         /*
 567          * if active found, use it; else pick entry from end of possible list.
 568          */
 569         if (link->irq.active) {
 570                 irq = link->irq.active;
 571         } else {
 572                 irq = link->irq.possible[link->irq.possible_count - 1];
 573         }
 574
 575         if (acpi_irq_balance || !link->irq.active) {
 576                 /*
 577                  * Select the best IRQ.  This is done in reverse to promote
 578                  * the use of IRQs 9, 10, 11, and >15.
 579                  */
 580                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 581                         if (acpi_irq_penalty[irq] >
 582                             acpi_irq_penalty[link->irq.possible[i]])
 583                                 irq = link->irq.possible[i];
 584                 }
 585         }
 586
 587         /* Attempt to enable the link device at this IRQ. */
 588         if (acpi_pci_link_set(link, irq)) {
 589                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 590                             "Try pci=noacpi or acpi=off\n",
 591                             acpi_device_name(link->device),
 592                             acpi_device_bid(link->device));
 593                 return -ENODEV;
 594         } else {
 595                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 596                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 597                        acpi_device_name(link->device),
 598                        acpi_device_bid(link->device), link->irq.active);
 599         }
 600
 601         link->irq.initialized = 1;
 602
 603         return 0;
 604 }
 605
 606 /*
 607  * acpi_pci_link_allocate_irq
 608  * success: return IRQ >= 0
 609  * failure: return -1
 610  */
 611
 612 int
 613 acpi_pci_link_allocate_irq(acpi_handle handle,
 614                            int index,
 615                            int *triggering, int *polarity, char **name)
 616 {
 617         int result = 0;
 618         struct acpi_device *device = NULL;
 619         struct acpi_pci_link *link = NULL;
 620
 621
 622         result = acpi_bus_get_device(handle, &device);
 623         if (result) {
 624                 printk(KERN_ERR PREFIX "Invalid link device\n");
 625                 return -1;
 626         }
 627
 628         link = acpi_driver_data(device);
 629         if (!link) {
 630                 printk(KERN_ERR PREFIX "Invalid link context\n");
 631                 return -1;
 632         }
 633
 634         /* TBD: Support multiple index (IRQ) entries per Link Device */
 635         if (index) {
 636                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 637                 return -1;
 638         }
 639
 640         mutex_lock(&acpi_link_lock);
 641         if (acpi_pci_link_allocate(link)) {
 642                 mutex_unlock(&acpi_link_lock);
 643                 return -1;
 644         }
 645
 646         if (!link->irq.active) {
 647                 mutex_unlock(&acpi_link_lock);
 648                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 649                 return -1;
 650         }
 651         link->refcnt++;
 652         mutex_unlock(&acpi_link_lock);
 653
 654         if (triggering)
 655                 *triggering = link->irq.triggering;
 656         if (polarity)
 657                 *polarity = link->irq.polarity;
 658         if (name)
 659                 *name = acpi_device_bid(link->device);
 660         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 661                           "Link %s is referenced\n",
 662                           acpi_device_bid(link->device)));
 663         return (link->irq.active);
 664 }
 665
 666 /*
 667  * We don't change link's irq information here.  After it is reenabled, we
 668  * continue use the info
 669  */
 670 int acpi_pci_link_free_irq(acpi_handle handle)
 671 {
 672         struct acpi_device *device = NULL;
 673         struct acpi_pci_link *link = NULL;
 674         acpi_status result;
 675
 676
 677         result = acpi_bus_get_device(handle, &device);
 678         if (result) {
 679                 printk(KERN_ERR PREFIX "Invalid link device\n");
 680                 return -1;
 681         }
 682
 683         link = acpi_driver_data(device);
 684         if (!link) {
 685                 printk(KERN_ERR PREFIX "Invalid link context\n");
 686                 return -1;
 687         }
 688
 689         mutex_lock(&acpi_link_lock);
 690         if (!link->irq.initialized) {
 691                 mutex_unlock(&acpi_link_lock);
 692                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 693                 return -1;
 694         }
 695 #ifdef  FUTURE_USE
 696         /*
 697          * The Link reference count allows us to _DISable an unused link
 698          * and suspend time, and set it again  on resume.
 699          * However, 2.6.12 still has irq_router.resume
 700          * which blindly restores the link state.
 701          * So we disable the reference count method
 702          * to prevent duplicate acpi_pci_link_set()
 703          * which would harm some systems
 704          */
 705         link->refcnt--;
 706 #endif
 707         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 708                           "Link %s is dereferenced\n",
 709                           acpi_device_bid(link->device)));
 710
 711         if (link->refcnt == 0) {
 712                 acpi_ut_evaluate_object(link->device->handle, "_DIS", 0, NULL);
 713         }
 714         mutex_unlock(&acpi_link_lock);
 715         return (link->irq.active);
 716 }
 717
 718 /* --------------------------------------------------------------------------
 719                                  Driver Interface
 720    -------------------------------------------------------------------------- */
 721
 722 static int acpi_pci_link_add(struct acpi_device *device)
 723 {
 724         int result = 0;
 725         struct acpi_pci_link *link = NULL;
 726         int i = 0;
 727         int found = 0;
 728
 729
 730         if (!device)
 731                 return -EINVAL;
 732
 733         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 734         if (!link)
 735                 return -ENOMEM;
 736
 737         link->device = device;
 738         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 739         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 740         acpi_driver_data(device) = link;
 741
 742         mutex_lock(&acpi_link_lock);
 743         result = acpi_pci_link_get_possible(link);
 744         if (result)
 745                 goto end;
 746
 747         /* query and set link->irq.active */
 748         acpi_pci_link_get_current(link);
 749
 750         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 751                acpi_device_bid(device));
 752         for (i = 0; i < link->irq.possible_count; i++) {
 753                 if (link->irq.active == link->irq.possible[i]) {
 754                         printk(" *%d", link->irq.possible[i]);
 755                         found = 1;
 756                 } else
 757                         printk(" %d", link->irq.possible[i]);
 758         }
 759
 760         printk(")");
 761
 762         if (!found)
 763                 printk(" *%d", link->irq.active);
 764
 765         if (!link->device->status.enabled)
 766                 printk(", disabled.");
 767
 768         printk("\n");
 769
 770         /* TBD: Acquire/release lock */
 771         list_add_tail(&link->node, &acpi_link.entries);
 772         acpi_link.count++;
 773
 774       end:
 775         /* disable all links -- to be activated on use */
 776         acpi_ut_evaluate_object(device->handle, "_DIS", 0, NULL);
 777         mutex_unlock(&acpi_link_lock);
 778
 779         if (result)
 780                 kfree(link);
 781
 782         return result;
 783 }
 784
 785 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 786 {
 787
 788         if (link->refcnt && link->irq.active && link->irq.initialized)
 789                 return (acpi_pci_link_set(link, link->irq.active));
 790         else
 791                 return 0;
 792 }
 793
 794 static int irqrouter_resume(struct sys_device *dev)
 795 {
 796         struct list_head *node = NULL;
 797         struct acpi_pci_link *link = NULL;
 798
 799
 800         /* Make sure SCI is enabled again (Apple firmware bug?) */
 801         acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
 802
 803         list_for_each(node, &acpi_link.entries) {
 804                 link = list_entry(node, struct acpi_pci_link, node);
 805                 if (!link) {
 806                         printk(KERN_ERR PREFIX "Invalid link context\n");
 807                         continue;
 808                 }
 809                 acpi_pci_link_resume(link);
 810         }
 811         return 0;
 812 }
 813
 814 static int acpi_pci_link_remove(struct acpi_device *device, int type)
 815 {
 816         struct acpi_pci_link *link = NULL;
 817
 818
 819         if (!device || !acpi_driver_data(device))
 820                 return -EINVAL;
 821
 822         link = acpi_driver_data(device);
 823
 824         mutex_lock(&acpi_link_lock);
 825         list_del(&link->node);
 826         mutex_unlock(&acpi_link_lock);
 827
 828         kfree(link);
 829
 830         return 0;
 831 }
 832
 833 /*
 834  * modify acpi_irq_penalty[] from cmdline
 835  */
 836 static int __init acpi_irq_penalty_update(char *str, int used)
 837 {
 838         int i;
 839
 840         for (i = 0; i < 16; i++) {
 841                 int retval;
 842                 int irq;
 843
 844                 retval = get_option(&str, &irq);
 845
 846                 if (!retval)
 847                         break;  /* no number found */
 848
 849                 if (irq < 0)
 850                         continue;
 851
 852                 if (irq >= ACPI_MAX_IRQS)
 853                         continue;
 854
 855                 if (used)
 856                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 857                 else
 858                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 859
 860                 if (retval != 2)        /* no next number */
 861                         break;
 862         }
 863         return 1;
 864 }
 865
 866 /*
 867  * We'd like PNP to call this routine for the
 868  * single ISA_USED value for each legacy device.
 869  * But instead it calls us with each POSSIBLE setting.
 870  * There is no ISA_POSSIBLE weight, so we simply use
 871  * the (small) PCI_USING penalty.
 872  */
 873 void acpi_penalize_isa_irq(int irq, int active)
 874 {
 875         if (active)
 876                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 877         else
 878                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 879 }
 880
 881 /*
 882  * Over-ride default table to reserve additional IRQs for use by ISA
 883  * e.g. acpi_irq_isa=5
 884  * Useful for telling ACPI how not to interfere with your ISA sound card.
 885  */
 886 static int __init acpi_irq_isa(char *str)
 887 {
 888         return acpi_irq_penalty_update(str, 1);
 889 }
 890
 891 __setup("acpi_irq_isa=", acpi_irq_isa);
 892
 893 /*
 894  * Over-ride default table to free additional IRQs for use by PCI
 895  * e.g. acpi_irq_pci=7,15
 896  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 897  */
 898 static int __init acpi_irq_pci(char *str)
 899 {
 900         return acpi_irq_penalty_update(str, 0);
 901 }
 902
 903 __setup("acpi_irq_pci=", acpi_irq_pci);
 904
 905 static int __init acpi_irq_nobalance_set(char *str)
 906 {
 907         acpi_irq_balance = 0;
 908         return 1;
 909 }
 910
 911 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 912
 913 int __init acpi_irq_balance_set(char *str)
 914 {
 915         acpi_irq_balance = 1;
 916         return 1;
 917 }
 918
 919 __setup("acpi_irq_balance", acpi_irq_balance_set);
 920
 921 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 922 static struct sysdev_class irqrouter_sysdev_class = {
 923         .name = "irqrouter",
 924         .resume = irqrouter_resume,
 925 };
 926
 927 static struct sys_device device_irqrouter = {
 928         .id = 0,
 929         .cls = &irqrouter_sysdev_class,
 930 };
 931
 932 static int __init irqrouter_init_sysfs(void)
 933 {
 934         int error;
 935
 936
 937         if (acpi_disabled || acpi_noirq)
 938                 return 0;
 939
 940         error = sysdev_class_register(&irqrouter_sysdev_class);
 941         if (!error)
 942                 error = sysdev_register(&device_irqrouter);
 943
 944         return error;
 945 }
 946
 947 device_initcall(irqrouter_init_sysfs);
 948
 949 static int __init acpi_pci_link_init(void)
 950 {
 951
 952         if (acpi_noirq)
 953                 return 0;
 954
 955         acpi_link.count = 0;
 956         INIT_LIST_HEAD(&acpi_link.entries);
 957
 958         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 959                 return -ENODEV;
 960
 961         return 0;
 962 }
 963
 964 subsys_initcall(acpi_pci_link_init);