drivers/acpi/pci_link.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
   7  *  Copyright (C) 2002       Dominik Brodowski <[email protected]>
   8  *
   9  * TBD:
  10  *      1. Support more than one IRQ resource entry per link device (index).
  11  *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  12  *         for IRQ management (e.g. start()->_SRS).
  13  */
  14
  15 #include <linux/syscore_ops.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/types.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/pm.h>
  22 #include <linux/pci.h>
  23 #include <linux/mutex.h>
  24 #include <linux/slab.h>
  25 #include <linux/acpi.h>
  26 #include <linux/irq.h>
  27
  28 #include "internal.h"
  29
  30 #define _COMPONENT                      ACPI_PCI_COMPONENT
  31 ACPI_MODULE_NAME("pci_link");
  32 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  33 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  34 #define ACPI_PCI_LINK_MAX_POSSIBLE      16
  35
  36 static int acpi_pci_link_add(struct acpi_device *device,
  37                              const struct acpi_device_id *not_used);
  38 static void acpi_pci_link_remove(struct acpi_device *device);
  39
  40 static const struct acpi_device_id link_device_ids[] = {
  41         {"PNP0C0F", 0},
  42         {"", 0},
  43 };
  44
  45 static struct acpi_scan_handler pci_link_handler = {
  46         .ids = link_device_ids,
  47         .attach = acpi_pci_link_add,
  48         .detach = acpi_pci_link_remove,
  49 };
  50
  51 /*
  52  * If a link is initialized, we never change its active and initialized
  53  * later even the link is disable. Instead, we just repick the active irq
  54  */
  55 struct acpi_pci_link_irq {
  56         u32 active;             /* Current IRQ */
  57         u8 triggering;          /* All IRQs */
  58         u8 polarity;            /* All IRQs */
  59         u8 resource_type;
  60         u8 possible_count;
  61         u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  62         u8 initialized:1;
  63         u8 reserved:7;
  64 };
  65
  66 struct acpi_pci_link {
  67         struct list_head                list;
  68         struct acpi_device              *device;
  69         struct acpi_pci_link_irq        irq;
  70         int                             refcnt;
  71 };
  72
  73 static LIST_HEAD(acpi_link_list);
  74 static DEFINE_MUTEX(acpi_link_lock);
  75 static int sci_irq = -1, sci_penalty;
  76
  77 /* --------------------------------------------------------------------------
  78                             PCI Link Device Management
  79    -------------------------------------------------------------------------- */
  80
  81 /*
  82  * set context (link) possible list from resource list
  83  */
  84 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
  85                                                 void *context)
  86 {
  87         struct acpi_pci_link *link = context;
  88         u32 i;
  89
  90         switch (resource->type) {
  91         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
  92         case ACPI_RESOURCE_TYPE_END_TAG:
  93                 return AE_OK;
  94         case ACPI_RESOURCE_TYPE_IRQ:
  95                 {
  96                         struct acpi_resource_irq *p = &resource->data.irq;
  97                         if (!p || !p->interrupt_count) {
  98                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  99                                                   "Blank _PRS IRQ resource\n"));
 100                                 return AE_OK;
 101                         }
 102                         for (i = 0;
 103                              (i < p->interrupt_count
 104                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 105                                 if (!p->interrupts[i]) {
 106                                         printk(KERN_WARNING PREFIX
 107                                                "Invalid _PRS IRQ %d\n",
 108                                                p->interrupts[i]);
 109                                         continue;
 110                                 }
 111                                 link->irq.possible[i] = p->interrupts[i];
 112                                 link->irq.possible_count++;
 113                         }
 114                         link->irq.triggering = p->triggering;
 115                         link->irq.polarity = p->polarity;
 116                         link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
 117                         break;
 118                 }
 119         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 120                 {
 121                         struct acpi_resource_extended_irq *p =
 122                             &resource->data.extended_irq;
 123                         if (!p || !p->interrupt_count) {
 124                                 printk(KERN_WARNING PREFIX
 125                                               "Blank _PRS EXT IRQ resource\n");
 126                                 return AE_OK;
 127                         }
 128                         for (i = 0;
 129                              (i < p->interrupt_count
 130                               && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 131                                 if (!p->interrupts[i]) {
 132                                         printk(KERN_WARNING PREFIX
 133                                                "Invalid _PRS IRQ %d\n",
 134                                                p->interrupts[i]);
 135                                         continue;
 136                                 }
 137                                 link->irq.possible[i] = p->interrupts[i];
 138                                 link->irq.possible_count++;
 139                         }
 140                         link->irq.triggering = p->triggering;
 141                         link->irq.polarity = p->polarity;
 142                         link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 143                         break;
 144                 }
 145         default:
 146                 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n",
 147                        resource->type);
 148                 return AE_OK;
 149         }
 150
 151         return AE_CTRL_TERMINATE;
 152 }
 153
 154 static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
 155 {
 156         acpi_status status;
 157
 158         status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS,
 159                                      acpi_pci_link_check_possible, link);
 160         if (ACPI_FAILURE(status)) {
 161                 acpi_handle_debug(link->device->handle, "_PRS not present or invalid");
 162                 return 0;
 163         }
 164
 165         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 166                           "Found %d possible IRQs\n",
 167                           link->irq.possible_count));
 168
 169         return 0;
 170 }
 171
 172 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
 173                                                void *context)
 174 {
 175         int *irq = context;
 176
 177         switch (resource->type) {
 178         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 179         case ACPI_RESOURCE_TYPE_END_TAG:
 180                 return AE_OK;
 181         case ACPI_RESOURCE_TYPE_IRQ:
 182                 {
 183                         struct acpi_resource_irq *p = &resource->data.irq;
 184                         if (!p || !p->interrupt_count) {
 185                                 /*
 186                                  * IRQ descriptors may have no IRQ# bits set,
 187                                  * particularly those those w/ _STA disabled
 188                                  */
 189                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 190                                                   "Blank _CRS IRQ resource\n"));
 191                                 return AE_OK;
 192                         }
 193                         *irq = p->interrupts[0];
 194                         break;
 195                 }
 196         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 197                 {
 198                         struct acpi_resource_extended_irq *p =
 199                             &resource->data.extended_irq;
 200                         if (!p || !p->interrupt_count) {
 201                                 /*
 202                                  * extended IRQ descriptors must
 203                                  * return at least 1 IRQ
 204                                  */
 205                                 printk(KERN_WARNING PREFIX
 206                                               "Blank _CRS EXT IRQ resource\n");
 207                                 return AE_OK;
 208                         }
 209                         *irq = p->interrupts[0];
 210                         break;
 211                 }
 212                 break;
 213         default:
 214                 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n",
 215                        resource->type);
 216                 return AE_OK;
 217         }
 218
 219         return AE_CTRL_TERMINATE;
 220 }
 221
 222 /*
 223  * Run _CRS and set link->irq.active
 224  *
 225  * return value:
 226  * 0 - success
 227  * !0 - failure
 228  */
 229 static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 230 {
 231         int result = 0;
 232         acpi_status status;
 233         int irq = 0;
 234
 235         link->irq.active = 0;
 236
 237         /* in practice, status disabled is meaningless, ignore it */
 238         if (acpi_strict) {
 239                 /* Query _STA, set link->device->status */
 240                 result = acpi_bus_get_status(link->device);
 241                 if (result) {
 242                         printk(KERN_ERR PREFIX "Unable to read status\n");
 243                         goto end;
 244                 }
 245
 246                 if (!link->device->status.enabled) {
 247                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 248                         return 0;
 249                 }
 250         }
 251
 252         /*
 253          * Query and parse _CRS to get the current IRQ assignment.
 254          */
 255
 256         status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS,
 257                                      acpi_pci_link_check_current, &irq);
 258         if (ACPI_FAILURE(status)) {
 259                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS"));
 260                 result = -ENODEV;
 261                 goto end;
 262         }
 263
 264         if (acpi_strict && !irq) {
 265                 printk(KERN_ERR PREFIX "_CRS returned 0\n");
 266                 result = -ENODEV;
 267         }
 268
 269         link->irq.active = irq;
 270
 271         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 272
 273       end:
 274         return result;
 275 }
 276
 277 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 278 {
 279         int result;
 280         acpi_status status;
 281         struct {
 282                 struct acpi_resource res;
 283                 struct acpi_resource end;
 284         } *resource;
 285         struct acpi_buffer buffer = { 0, NULL };
 286
 287         if (!irq)
 288                 return -EINVAL;
 289
 290         resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
 291         if (!resource)
 292                 return -ENOMEM;
 293
 294         buffer.length = sizeof(*resource) + 1;
 295         buffer.pointer = resource;
 296
 297         switch (link->irq.resource_type) {
 298         case ACPI_RESOURCE_TYPE_IRQ:
 299                 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
 300                 resource->res.length = sizeof(struct acpi_resource);
 301                 resource->res.data.irq.triggering = link->irq.triggering;
 302                 resource->res.data.irq.polarity =
 303                     link->irq.polarity;
 304                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 305                         resource->res.data.irq.shareable =
 306                             ACPI_EXCLUSIVE;
 307                 else
 308                         resource->res.data.irq.shareable = ACPI_SHARED;
 309                 resource->res.data.irq.interrupt_count = 1;
 310                 resource->res.data.irq.interrupts[0] = irq;
 311                 break;
 312
 313         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 314                 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
 315                 resource->res.length = sizeof(struct acpi_resource);
 316                 resource->res.data.extended_irq.producer_consumer =
 317                     ACPI_CONSUMER;
 318                 resource->res.data.extended_irq.triggering =
 319                     link->irq.triggering;
 320                 resource->res.data.extended_irq.polarity =
 321                     link->irq.polarity;
 322                 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
 323                         resource->res.data.extended_irq.shareable =
 324                             ACPI_EXCLUSIVE;
 325                 else
 326                         resource->res.data.extended_irq.shareable = ACPI_SHARED;
 327                 resource->res.data.extended_irq.interrupt_count = 1;
 328                 resource->res.data.extended_irq.interrupts[0] = irq;
 329                 /* ignore resource_source, it's optional */
 330                 break;
 331         default:
 332                 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type);
 333                 result = -EINVAL;
 334                 goto end;
 335
 336         }
 337         resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
 338         resource->end.length = sizeof(struct acpi_resource);
 339
 340         /* Attempt to set the resource */
 341         status = acpi_set_current_resources(link->device->handle, &buffer);
 342
 343         /* check for total failure */
 344         if (ACPI_FAILURE(status)) {
 345                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS"));
 346                 result = -ENODEV;
 347                 goto end;
 348         }
 349
 350         /* Query _STA, set device->status */
 351         result = acpi_bus_get_status(link->device);
 352         if (result) {
 353                 printk(KERN_ERR PREFIX "Unable to read status\n");
 354                 goto end;
 355         }
 356         if (!link->device->status.enabled) {
 357                 printk(KERN_WARNING PREFIX
 358                               "%s [%s] disabled and referenced, BIOS bug\n",
 359                               acpi_device_name(link->device),
 360                               acpi_device_bid(link->device));
 361         }
 362
 363         /* Query _CRS, set link->irq.active */
 364         result = acpi_pci_link_get_current(link);
 365         if (result) {
 366                 goto end;
 367         }
 368
 369         /*
 370          * Is current setting not what we set?
 371          * set link->irq.active
 372          */
 373         if (link->irq.active != irq) {
 374                 /*
 375                  * policy: when _CRS doesn't return what we just _SRS
 376                  * assume _SRS worked and override _CRS value.
 377                  */
 378                 printk(KERN_WARNING PREFIX
 379                               "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 380                               acpi_device_name(link->device),
 381                               acpi_device_bid(link->device), link->irq.active, irq);
 382                 link->irq.active = irq;
 383         }
 384
 385         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 386
 387       end:
 388         kfree(resource);
 389         return result;
 390 }
 391
 392 /* --------------------------------------------------------------------------
 393                             PCI Link IRQ Management
 394    -------------------------------------------------------------------------- */
 395
 396 /*
 397  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 398  * Link Devices to move the PIRQs around to minimize sharing.
 399  *
 400  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 401  * that the BIOS has already set to active.  This is necessary because
 402  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 403  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 404  * even if acpi_irq_nobalance is set.
 405  *
 406  * A tables of penalties avoids directing PCI interrupts to well known
 407  * ISA IRQs. Boot params are available to over-ride the default table:
 408  *
 409  * List interrupts that are free for PCI use.
 410  * acpi_irq_pci=n[,m]
 411  *
 412  * List interrupts that should not be used for PCI:
 413  * acpi_irq_isa=n[,m]
 414  *
 415  * Note that PCI IRQ routers have a list of possible IRQs,
 416  * which may not include the IRQs this table says are available.
 417  *
 418  * Since this heuristic can't tell the difference between a link
 419  * that no device will attach to, vs. a link which may be shared
 420  * by multiple active devices -- it is not optimal.
 421  *
 422  * If interrupt performance is that important, get an IO-APIC system
 423  * with a pin dedicated to each device.  Or for that matter, an MSI
 424  * enabled system.
 425  */
 426
 427 #define ACPI_MAX_ISA_IRQS       16
 428
 429 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 430 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 431 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 432 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 433 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 434
 435 static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = {
 436         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 437         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 438         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 439         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 440         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 441         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 442         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 443         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 444         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 445         0,                              /* IRQ9  PCI, often acpi */
 446         0,                              /* IRQ10 PCI */
 447         0,                              /* IRQ11 PCI */
 448         PIRQ_PENALTY_ISA_USED,          /* IRQ12 mouse */
 449         PIRQ_PENALTY_ISA_USED,          /* IRQ13 fpe, sometimes */
 450         PIRQ_PENALTY_ISA_USED,          /* IRQ14 ide0 */
 451         PIRQ_PENALTY_ISA_USED,          /* IRQ15 ide1 */
 452         /* >IRQ15 */
 453 };
 454
 455 static int acpi_irq_pci_sharing_penalty(int irq)
 456 {
 457         struct acpi_pci_link *link;
 458         int penalty = 0;
 459         int i;
 460
 461         list_for_each_entry(link, &acpi_link_list, list) {
 462                 /*
 463                  * If a link is active, penalize its IRQ heavily
 464                  * so we try to choose a different IRQ.
 465                  */
 466                 if (link->irq.active && link->irq.active == irq)
 467                         penalty += PIRQ_PENALTY_PCI_USING;
 468
 469                 /*
 470                  * penalize the IRQs PCI might use, but not as severely.
 471                  */
 472                 for (i = 0; i < link->irq.possible_count; i++)
 473                         if (link->irq.possible[i] == irq)
 474                                 penalty += PIRQ_PENALTY_PCI_POSSIBLE /
 475                                         link->irq.possible_count;
 476         }
 477
 478         return penalty;
 479 }
 480
 481 static int acpi_irq_get_penalty(int irq)
 482 {
 483         int penalty = 0;
 484
 485         if (irq == sci_irq)
 486                 penalty += sci_penalty;
 487
 488         if (irq < ACPI_MAX_ISA_IRQS)
 489                 return penalty + acpi_isa_irq_penalty[irq];
 490
 491         return penalty + acpi_irq_pci_sharing_penalty(irq);
 492 }
 493
 494 int __init acpi_irq_penalty_init(void)
 495 {
 496         struct acpi_pci_link *link;
 497         int i;
 498
 499         /*
 500          * Update penalties to facilitate IRQ balancing.
 501          */
 502         list_for_each_entry(link, &acpi_link_list, list) {
 503
 504                 /*
 505                  * reflect the possible and active irqs in the penalty table --
 506                  * useful for breaking ties.
 507                  */
 508                 if (link->irq.possible_count) {
 509                         int penalty =
 510                             PIRQ_PENALTY_PCI_POSSIBLE /
 511                             link->irq.possible_count;
 512
 513                         for (i = 0; i < link->irq.possible_count; i++) {
 514                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
 515                                         acpi_isa_irq_penalty[link->irq.
 516                                                          possible[i]] +=
 517                                             penalty;
 518                         }
 519
 520                 } else if (link->irq.active &&
 521                                 (link->irq.active < ACPI_MAX_ISA_IRQS)) {
 522                         acpi_isa_irq_penalty[link->irq.active] +=
 523                             PIRQ_PENALTY_PCI_POSSIBLE;
 524                 }
 525         }
 526
 527         return 0;
 528 }
 529
 530 static int acpi_irq_balance = -1;       /* 0: static, 1: balance */
 531
 532 static int acpi_pci_link_allocate(struct acpi_pci_link *link)
 533 {
 534         int irq;
 535         int i;
 536
 537         if (link->irq.initialized) {
 538                 if (link->refcnt == 0)
 539                         /* This means the link is disabled but initialized */
 540                         acpi_pci_link_set(link, link->irq.active);
 541                 return 0;
 542         }
 543
 544         /*
 545          * search for active IRQ in list of possible IRQs.
 546          */
 547         for (i = 0; i < link->irq.possible_count; ++i) {
 548                 if (link->irq.active == link->irq.possible[i])
 549                         break;
 550         }
 551         /*
 552          * forget active IRQ that is not in possible list
 553          */
 554         if (i == link->irq.possible_count) {
 555                 if (acpi_strict)
 556                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 557                                       " in _PRS\n", link->irq.active);
 558                 link->irq.active = 0;
 559         }
 560
 561         /*
 562          * if active found, use it; else pick entry from end of possible list.
 563          */
 564         if (link->irq.active)
 565                 irq = link->irq.active;
 566         else
 567                 irq = link->irq.possible[link->irq.possible_count - 1];
 568
 569         if (acpi_irq_balance || !link->irq.active) {
 570                 /*
 571                  * Select the best IRQ.  This is done in reverse to promote
 572                  * the use of IRQs 9, 10, 11, and >15.
 573                  */
 574                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 575                         if (acpi_irq_get_penalty(irq) >
 576                             acpi_irq_get_penalty(link->irq.possible[i]))
 577                                 irq = link->irq.possible[i];
 578                 }
 579         }
 580         if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
 581                 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
 582                             "Try pci=noacpi or acpi=off\n",
 583                             acpi_device_name(link->device),
 584                             acpi_device_bid(link->device));
 585                 return -ENODEV;
 586         }
 587
 588         /* Attempt to enable the link device at this IRQ. */
 589         if (acpi_pci_link_set(link, irq)) {
 590                 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
 591                             "Try pci=noacpi or acpi=off\n",
 592                             acpi_device_name(link->device),
 593                             acpi_device_bid(link->device));
 594                 return -ENODEV;
 595         } else {
 596                 if (link->irq.active < ACPI_MAX_ISA_IRQS)
 597                         acpi_isa_irq_penalty[link->irq.active] +=
 598                                 PIRQ_PENALTY_PCI_USING;
 599
 600                 pr_info("%s [%s] enabled at IRQ %d\n",
 601                        acpi_device_name(link->device),
 602                        acpi_device_bid(link->device), link->irq.active);
 603         }
 604
 605         link->irq.initialized = 1;
 606         return 0;
 607 }
 608
 609 /*
 610  * acpi_pci_link_allocate_irq
 611  * success: return IRQ >= 0
 612  * failure: return -1
 613  */
 614 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
 615                                int *polarity, char **name)
 616 {
 617         int result;
 618         struct acpi_device *device;
 619         struct acpi_pci_link *link;
 620
 621         result = acpi_bus_get_device(handle, &device);
 622         if (result) {
 623                 printk(KERN_ERR PREFIX "Invalid link device\n");
 624                 return -1;
 625         }
 626
 627         link = acpi_driver_data(device);
 628         if (!link) {
 629                 printk(KERN_ERR PREFIX "Invalid link context\n");
 630                 return -1;
 631         }
 632
 633         /* TBD: Support multiple index (IRQ) entries per Link Device */
 634         if (index) {
 635                 printk(KERN_ERR PREFIX "Invalid index %d\n", index);
 636                 return -1;
 637         }
 638
 639         mutex_lock(&acpi_link_lock);
 640         if (acpi_pci_link_allocate(link)) {
 641                 mutex_unlock(&acpi_link_lock);
 642                 return -1;
 643         }
 644
 645         if (!link->irq.active) {
 646                 mutex_unlock(&acpi_link_lock);
 647                 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
 648                 return -1;
 649         }
 650         link->refcnt++;
 651         mutex_unlock(&acpi_link_lock);
 652
 653         if (triggering)
 654                 *triggering = link->irq.triggering;
 655         if (polarity)
 656                 *polarity = link->irq.polarity;
 657         if (name)
 658                 *name = acpi_device_bid(link->device);
 659         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 660                           "Link %s is referenced\n",
 661                           acpi_device_bid(link->device)));
 662         return link->irq.active;
 663 }
 664
 665 /*
 666  * We don't change link's irq information here.  After it is reenabled, we
 667  * continue use the info
 668  */
 669 int acpi_pci_link_free_irq(acpi_handle handle)
 670 {
 671         struct acpi_device *device;
 672         struct acpi_pci_link *link;
 673         acpi_status result;
 674
 675         result = acpi_bus_get_device(handle, &device);
 676         if (result) {
 677                 printk(KERN_ERR PREFIX "Invalid link device\n");
 678                 return -1;
 679         }
 680
 681         link = acpi_driver_data(device);
 682         if (!link) {
 683                 printk(KERN_ERR PREFIX "Invalid link context\n");
 684                 return -1;
 685         }
 686
 687         mutex_lock(&acpi_link_lock);
 688         if (!link->irq.initialized) {
 689                 mutex_unlock(&acpi_link_lock);
 690                 printk(KERN_ERR PREFIX "Link isn't initialized\n");
 691                 return -1;
 692         }
 693 #ifdef  FUTURE_USE
 694         /*
 695          * The Link reference count allows us to _DISable an unused link
 696          * and suspend time, and set it again  on resume.
 697          * However, 2.6.12 still has irq_router.resume
 698          * which blindly restores the link state.
 699          * So we disable the reference count method
 700          * to prevent duplicate acpi_pci_link_set()
 701          * which would harm some systems
 702          */
 703         link->refcnt--;
 704 #endif
 705         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 706                           "Link %s is dereferenced\n",
 707                           acpi_device_bid(link->device)));
 708
 709         if (link->refcnt == 0)
 710                 acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
 711
 712         mutex_unlock(&acpi_link_lock);
 713         return link->irq.active;
 714 }
 715
 716 /* --------------------------------------------------------------------------
 717                                  Driver Interface
 718    -------------------------------------------------------------------------- */
 719
 720 static int acpi_pci_link_add(struct acpi_device *device,
 721                              const struct acpi_device_id *not_used)
 722 {
 723         int result;
 724         struct acpi_pci_link *link;
 725         int i;
 726         int found = 0;
 727
 728         link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 729         if (!link)
 730                 return -ENOMEM;
 731
 732         link->device = device;
 733         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 734         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 735         device->driver_data = link;
 736
 737         mutex_lock(&acpi_link_lock);
 738         result = acpi_pci_link_get_possible(link);
 739         if (result)
 740                 goto end;
 741
 742         /* query and set link->irq.active */
 743         acpi_pci_link_get_current(link);
 744
 745         printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 746                acpi_device_bid(device));
 747         for (i = 0; i < link->irq.possible_count; i++) {
 748                 if (link->irq.active == link->irq.possible[i]) {
 749                         printk(KERN_CONT " *%d", link->irq.possible[i]);
 750                         found = 1;
 751                 } else
 752                         printk(KERN_CONT " %d", link->irq.possible[i]);
 753         }
 754
 755         printk(KERN_CONT ")");
 756
 757         if (!found)
 758                 printk(KERN_CONT " *%d", link->irq.active);
 759
 760         if (!link->device->status.enabled)
 761                 printk(KERN_CONT ", disabled.");
 762
 763         printk(KERN_CONT "\n");
 764
 765         list_add_tail(&link->list, &acpi_link_list);
 766
 767       end:
 768         /* disable all links -- to be activated on use */
 769         acpi_evaluate_object(device->handle, "_DIS", NULL, NULL);
 770         mutex_unlock(&acpi_link_lock);
 771
 772         if (result)
 773                 kfree(link);
 774
 775         return result < 0 ? result : 1;
 776 }
 777
 778 static int acpi_pci_link_resume(struct acpi_pci_link *link)
 779 {
 780         if (link->refcnt && link->irq.active && link->irq.initialized)
 781                 return (acpi_pci_link_set(link, link->irq.active));
 782
 783         return 0;
 784 }
 785
 786 static void irqrouter_resume(void)
 787 {
 788         struct acpi_pci_link *link;
 789
 790         list_for_each_entry(link, &acpi_link_list, list) {
 791                 acpi_pci_link_resume(link);
 792         }
 793 }
 794
 795 static void acpi_pci_link_remove(struct acpi_device *device)
 796 {
 797         struct acpi_pci_link *link;
 798
 799         link = acpi_driver_data(device);
 800
 801         mutex_lock(&acpi_link_lock);
 802         list_del(&link->list);
 803         mutex_unlock(&acpi_link_lock);
 804
 805         kfree(link);
 806 }
 807
 808 /*
 809  * modify acpi_isa_irq_penalty[] from cmdline
 810  */
 811 static int __init acpi_irq_penalty_update(char *str, int used)
 812 {
 813         int i;
 814
 815         for (i = 0; i < 16; i++) {
 816                 int retval;
 817                 int irq;
 818                 int new_penalty;
 819
 820                 retval = get_option(&str, &irq);
 821
 822                 if (!retval)
 823                         break;  /* no number found */
 824
 825                 /* see if this is a ISA IRQ */
 826                 if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
 827                         continue;
 828
 829                 if (used)
 830                         new_penalty = acpi_isa_irq_penalty[irq] +
 831                                         PIRQ_PENALTY_ISA_USED;
 832                 else
 833                         new_penalty = 0;
 834
 835                 acpi_isa_irq_penalty[irq] = new_penalty;
 836                 if (retval != 2)        /* no next number */
 837                         break;
 838         }
 839         return 1;
 840 }
 841
 842 /*
 843  * We'd like PNP to call this routine for the
 844  * single ISA_USED value for each legacy device.
 845  * But instead it calls us with each POSSIBLE setting.
 846  * There is no ISA_POSSIBLE weight, so we simply use
 847  * the (small) PCI_USING penalty.
 848  */
 849 void acpi_penalize_isa_irq(int irq, int active)
 850 {
 851         if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
 852                 acpi_isa_irq_penalty[irq] +=
 853                   (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
 854 }
 855
 856 bool acpi_isa_irq_available(int irq)
 857 {
 858         return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
 859                     acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
 860 }
 861
 862 void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 863 {
 864         sci_irq = irq;
 865
 866         if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
 867             polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
 868                 sci_penalty = PIRQ_PENALTY_PCI_USING;
 869         else
 870                 sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
 871 }
 872
 873 /*
 874  * Over-ride default table to reserve additional IRQs for use by ISA
 875  * e.g. acpi_irq_isa=5
 876  * Useful for telling ACPI how not to interfere with your ISA sound card.
 877  */
 878 static int __init acpi_irq_isa(char *str)
 879 {
 880         return acpi_irq_penalty_update(str, 1);
 881 }
 882
 883 __setup("acpi_irq_isa=", acpi_irq_isa);
 884
 885 /*
 886  * Over-ride default table to free additional IRQs for use by PCI
 887  * e.g. acpi_irq_pci=7,15
 888  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 889  */
 890 static int __init acpi_irq_pci(char *str)
 891 {
 892         return acpi_irq_penalty_update(str, 0);
 893 }
 894
 895 __setup("acpi_irq_pci=", acpi_irq_pci);
 896
 897 static int __init acpi_irq_nobalance_set(char *str)
 898 {
 899         acpi_irq_balance = 0;
 900         return 1;
 901 }
 902
 903 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 904
 905 static int __init acpi_irq_balance_set(char *str)
 906 {
 907         acpi_irq_balance = 1;
 908         return 1;
 909 }
 910
 911 __setup("acpi_irq_balance", acpi_irq_balance_set);
 912
 913 static struct syscore_ops irqrouter_syscore_ops = {
 914         .resume = irqrouter_resume,
 915 };
 916
 917 void __init acpi_pci_link_init(void)
 918 {
 919         if (acpi_noirq)
 920                 return;
 921
 922         if (acpi_irq_balance == -1) {
 923                 /* no command line switch: enable balancing in IOAPIC mode */
 924                 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 925                         acpi_irq_balance = 1;
 926                 else
 927                         acpi_irq_balance = 0;
 928         }
 929         register_syscore_ops(&irqrouter_syscore_ops);
 930         acpi_scan_add_handler(&pci_link_handler);
 931 }