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 <andrew.grover@intel.com> 6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 7 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de> 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 31ACPI_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 36static int acpi_pci_link_add(struct acpi_device *device, 37 const struct acpi_device_id *not_used); 38static void acpi_pci_link_remove(struct acpi_device *device); 39 40static const struct acpi_device_id link_device_ids[] = { 41 {"PNP0C0F", 0}, 42 {"", 0}, 43}; 44 45static 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 */ 55struct 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 66struct 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 73static LIST_HEAD(acpi_link_list); 74static DEFINE_MUTEX(acpi_link_lock); 75static 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 */ 84static 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 154static 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 172static 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 */ 229static 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 277static 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 435static 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 455static 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 481static 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 494int __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 530static int acpi_irq_balance = -1; /* 0: static, 1: balance */ 531 532static 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 */ 614int 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 */ 669int 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 720static 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 778static 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 786static 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 795static 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 */ 811static 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 */ 849void 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 856bool 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 862void 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 */ 878static 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 */ 890static 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 897static 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 905static 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 913static struct syscore_ops irqrouter_syscore_ops = { 914 .resume = irqrouter_resume, 915}; 916 917void __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} 932