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 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_FILE_INFO "info" 35 #define ACPI_PCI_LINK_FILE_STATUS "state" 36 #define ACPI_PCI_LINK_MAX_POSSIBLE 16 37 38 static int acpi_pci_link_add(struct acpi_device *device, 39 const struct acpi_device_id *not_used); 40 static void acpi_pci_link_remove(struct acpi_device *device); 41 42 static const struct acpi_device_id link_device_ids[] = { 43 {"PNP0C0F", 0}, 44 {"", 0}, 45 }; 46 47 static struct acpi_scan_handler pci_link_handler = { 48 .ids = link_device_ids, 49 .attach = acpi_pci_link_add, 50 .detach = acpi_pci_link_remove, 51 }; 52 53 /* 54 * If a link is initialized, we never change its active and initialized 55 * later even the link is disable. Instead, we just repick the active irq 56 */ 57 struct acpi_pci_link_irq { 58 u32 active; /* Current IRQ */ 59 u8 triggering; /* All IRQs */ 60 u8 polarity; /* All IRQs */ 61 u8 resource_type; 62 u8 possible_count; 63 u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE]; 64 u8 initialized:1; 65 u8 reserved:7; 66 }; 67 68 struct acpi_pci_link { 69 struct list_head list; 70 struct acpi_device *device; 71 struct acpi_pci_link_irq irq; 72 int refcnt; 73 }; 74 75 static LIST_HEAD(acpi_link_list); 76 static DEFINE_MUTEX(acpi_link_lock); 77 static int sci_irq = -1, sci_penalty; 78 79 /* -------------------------------------------------------------------------- 80 PCI Link Device Management 81 -------------------------------------------------------------------------- */ 82 83 /* 84 * set context (link) possible list from resource list 85 */ 86 static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource, 87 void *context) 88 { 89 struct acpi_pci_link *link = context; 90 u32 i; 91 92 switch (resource->type) { 93 case ACPI_RESOURCE_TYPE_START_DEPENDENT: 94 case ACPI_RESOURCE_TYPE_END_TAG: 95 return AE_OK; 96 case ACPI_RESOURCE_TYPE_IRQ: 97 { 98 struct acpi_resource_irq *p = &resource->data.irq; 99 if (!p || !p->interrupt_count) { 100 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 101 "Blank _PRS IRQ resource\n")); 102 return AE_OK; 103 } 104 for (i = 0; 105 (i < p->interrupt_count 106 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) { 107 if (!p->interrupts[i]) { 108 printk(KERN_WARNING PREFIX 109 "Invalid _PRS IRQ %d\n", 110 p->interrupts[i]); 111 continue; 112 } 113 link->irq.possible[i] = p->interrupts[i]; 114 link->irq.possible_count++; 115 } 116 link->irq.triggering = p->triggering; 117 link->irq.polarity = p->polarity; 118 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ; 119 break; 120 } 121 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: 122 { 123 struct acpi_resource_extended_irq *p = 124 &resource->data.extended_irq; 125 if (!p || !p->interrupt_count) { 126 printk(KERN_WARNING PREFIX 127 "Blank _PRS EXT IRQ resource\n"); 128 return AE_OK; 129 } 130 for (i = 0; 131 (i < p->interrupt_count 132 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) { 133 if (!p->interrupts[i]) { 134 printk(KERN_WARNING PREFIX 135 "Invalid _PRS IRQ %d\n", 136 p->interrupts[i]); 137 continue; 138 } 139 link->irq.possible[i] = p->interrupts[i]; 140 link->irq.possible_count++; 141 } 142 link->irq.triggering = p->triggering; 143 link->irq.polarity = p->polarity; 144 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ; 145 break; 146 } 147 default: 148 printk(KERN_ERR PREFIX "_PRS resource type 0x%x isn't an IRQ\n", 149 resource->type); 150 return AE_OK; 151 } 152 153 return AE_CTRL_TERMINATE; 154 } 155 156 static int acpi_pci_link_get_possible(struct acpi_pci_link *link) 157 { 158 acpi_status status; 159 160 status = acpi_walk_resources(link->device->handle, METHOD_NAME__PRS, 161 acpi_pci_link_check_possible, link); 162 if (ACPI_FAILURE(status)) { 163 acpi_handle_debug(link->device->handle, "_PRS not present or invalid"); 164 return 0; 165 } 166 167 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 168 "Found %d possible IRQs\n", 169 link->irq.possible_count)); 170 171 return 0; 172 } 173 174 static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource, 175 void *context) 176 { 177 int *irq = context; 178 179 switch (resource->type) { 180 case ACPI_RESOURCE_TYPE_START_DEPENDENT: 181 case ACPI_RESOURCE_TYPE_END_TAG: 182 return AE_OK; 183 case ACPI_RESOURCE_TYPE_IRQ: 184 { 185 struct acpi_resource_irq *p = &resource->data.irq; 186 if (!p || !p->interrupt_count) { 187 /* 188 * IRQ descriptors may have no IRQ# bits set, 189 * particularly those those w/ _STA disabled 190 */ 191 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 192 "Blank _CRS IRQ resource\n")); 193 return AE_OK; 194 } 195 *irq = p->interrupts[0]; 196 break; 197 } 198 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: 199 { 200 struct acpi_resource_extended_irq *p = 201 &resource->data.extended_irq; 202 if (!p || !p->interrupt_count) { 203 /* 204 * extended IRQ descriptors must 205 * return at least 1 IRQ 206 */ 207 printk(KERN_WARNING PREFIX 208 "Blank _CRS EXT IRQ resource\n"); 209 return AE_OK; 210 } 211 *irq = p->interrupts[0]; 212 break; 213 } 214 break; 215 default: 216 printk(KERN_ERR PREFIX "_CRS resource type 0x%x isn't an IRQ\n", 217 resource->type); 218 return AE_OK; 219 } 220 221 return AE_CTRL_TERMINATE; 222 } 223 224 /* 225 * Run _CRS and set link->irq.active 226 * 227 * return value: 228 * 0 - success 229 * !0 - failure 230 */ 231 static int acpi_pci_link_get_current(struct acpi_pci_link *link) 232 { 233 int result = 0; 234 acpi_status status; 235 int irq = 0; 236 237 link->irq.active = 0; 238 239 /* in practice, status disabled is meaningless, ignore it */ 240 if (acpi_strict) { 241 /* Query _STA, set link->device->status */ 242 result = acpi_bus_get_status(link->device); 243 if (result) { 244 printk(KERN_ERR PREFIX "Unable to read status\n"); 245 goto end; 246 } 247 248 if (!link->device->status.enabled) { 249 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n")); 250 return 0; 251 } 252 } 253 254 /* 255 * Query and parse _CRS to get the current IRQ assignment. 256 */ 257 258 status = acpi_walk_resources(link->device->handle, METHOD_NAME__CRS, 259 acpi_pci_link_check_current, &irq); 260 if (ACPI_FAILURE(status)) { 261 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _CRS")); 262 result = -ENODEV; 263 goto end; 264 } 265 266 if (acpi_strict && !irq) { 267 printk(KERN_ERR PREFIX "_CRS returned 0\n"); 268 result = -ENODEV; 269 } 270 271 link->irq.active = irq; 272 273 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active)); 274 275 end: 276 return result; 277 } 278 279 static int acpi_pci_link_set(struct acpi_pci_link *link, int irq) 280 { 281 int result; 282 acpi_status status; 283 struct { 284 struct acpi_resource res; 285 struct acpi_resource end; 286 } *resource; 287 struct acpi_buffer buffer = { 0, NULL }; 288 289 if (!irq) 290 return -EINVAL; 291 292 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL); 293 if (!resource) 294 return -ENOMEM; 295 296 buffer.length = sizeof(*resource) + 1; 297 buffer.pointer = resource; 298 299 switch (link->irq.resource_type) { 300 case ACPI_RESOURCE_TYPE_IRQ: 301 resource->res.type = ACPI_RESOURCE_TYPE_IRQ; 302 resource->res.length = sizeof(struct acpi_resource); 303 resource->res.data.irq.triggering = link->irq.triggering; 304 resource->res.data.irq.polarity = 305 link->irq.polarity; 306 if (link->irq.triggering == ACPI_EDGE_SENSITIVE) 307 resource->res.data.irq.shareable = 308 ACPI_EXCLUSIVE; 309 else 310 resource->res.data.irq.shareable = ACPI_SHARED; 311 resource->res.data.irq.interrupt_count = 1; 312 resource->res.data.irq.interrupts[0] = irq; 313 break; 314 315 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: 316 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ; 317 resource->res.length = sizeof(struct acpi_resource); 318 resource->res.data.extended_irq.producer_consumer = 319 ACPI_CONSUMER; 320 resource->res.data.extended_irq.triggering = 321 link->irq.triggering; 322 resource->res.data.extended_irq.polarity = 323 link->irq.polarity; 324 if (link->irq.triggering == ACPI_EDGE_SENSITIVE) 325 resource->res.data.irq.shareable = 326 ACPI_EXCLUSIVE; 327 else 328 resource->res.data.irq.shareable = ACPI_SHARED; 329 resource->res.data.extended_irq.interrupt_count = 1; 330 resource->res.data.extended_irq.interrupts[0] = irq; 331 /* ignore resource_source, it's optional */ 332 break; 333 default: 334 printk(KERN_ERR PREFIX "Invalid Resource_type %d\n", link->irq.resource_type); 335 result = -EINVAL; 336 goto end; 337 338 } 339 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG; 340 resource->end.length = sizeof(struct acpi_resource); 341 342 /* Attempt to set the resource */ 343 status = acpi_set_current_resources(link->device->handle, &buffer); 344 345 /* check for total failure */ 346 if (ACPI_FAILURE(status)) { 347 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRS")); 348 result = -ENODEV; 349 goto end; 350 } 351 352 /* Query _STA, set device->status */ 353 result = acpi_bus_get_status(link->device); 354 if (result) { 355 printk(KERN_ERR PREFIX "Unable to read status\n"); 356 goto end; 357 } 358 if (!link->device->status.enabled) { 359 printk(KERN_WARNING PREFIX 360 "%s [%s] disabled and referenced, BIOS bug\n", 361 acpi_device_name(link->device), 362 acpi_device_bid(link->device)); 363 } 364 365 /* Query _CRS, set link->irq.active */ 366 result = acpi_pci_link_get_current(link); 367 if (result) { 368 goto end; 369 } 370 371 /* 372 * Is current setting not what we set? 373 * set link->irq.active 374 */ 375 if (link->irq.active != irq) { 376 /* 377 * policy: when _CRS doesn't return what we just _SRS 378 * assume _SRS worked and override _CRS value. 379 */ 380 printk(KERN_WARNING PREFIX 381 "%s [%s] BIOS reported IRQ %d, using IRQ %d\n", 382 acpi_device_name(link->device), 383 acpi_device_bid(link->device), link->irq.active, irq); 384 link->irq.active = irq; 385 } 386 387 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active)); 388 389 end: 390 kfree(resource); 391 return result; 392 } 393 394 /* -------------------------------------------------------------------------- 395 PCI Link IRQ Management 396 -------------------------------------------------------------------------- */ 397 398 /* 399 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt 400 * Link Devices to move the PIRQs around to minimize sharing. 401 * 402 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs 403 * that the BIOS has already set to active. This is necessary because 404 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that 405 * if the BIOS doesn't set a Link Device active, ACPI needs to program it 406 * even if acpi_irq_nobalance is set. 407 * 408 * A tables of penalties avoids directing PCI interrupts to well known 409 * ISA IRQs. Boot params are available to over-ride the default table: 410 * 411 * List interrupts that are free for PCI use. 412 * acpi_irq_pci=n[,m] 413 * 414 * List interrupts that should not be used for PCI: 415 * acpi_irq_isa=n[,m] 416 * 417 * Note that PCI IRQ routers have a list of possible IRQs, 418 * which may not include the IRQs this table says are available. 419 * 420 * Since this heuristic can't tell the difference between a link 421 * that no device will attach to, vs. a link which may be shared 422 * by multiple active devices -- it is not optimal. 423 * 424 * If interrupt performance is that important, get an IO-APIC system 425 * with a pin dedicated to each device. Or for that matter, an MSI 426 * enabled system. 427 */ 428 429 #define ACPI_MAX_ISA_IRQS 16 430 431 #define PIRQ_PENALTY_PCI_POSSIBLE (16*16) 432 #define PIRQ_PENALTY_PCI_USING (16*16*16) 433 #define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16) 434 #define PIRQ_PENALTY_ISA_USED (16*16*16*16*16) 435 #define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16) 436 437 static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = { 438 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */ 439 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */ 440 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */ 441 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */ 442 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */ 443 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */ 444 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */ 445 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */ 446 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */ 447 0, /* IRQ9 PCI, often acpi */ 448 0, /* IRQ10 PCI */ 449 0, /* IRQ11 PCI */ 450 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */ 451 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */ 452 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */ 453 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */ 454 /* >IRQ15 */ 455 }; 456 457 static int acpi_irq_pci_sharing_penalty(int irq) 458 { 459 struct acpi_pci_link *link; 460 int penalty = 0; 461 int i; 462 463 list_for_each_entry(link, &acpi_link_list, list) { 464 /* 465 * If a link is active, penalize its IRQ heavily 466 * so we try to choose a different IRQ. 467 */ 468 if (link->irq.active && link->irq.active == irq) 469 penalty += PIRQ_PENALTY_PCI_USING; 470 471 /* 472 * penalize the IRQs PCI might use, but not as severely. 473 */ 474 for (i = 0; i < link->irq.possible_count; i++) 475 if (link->irq.possible[i] == irq) 476 penalty += PIRQ_PENALTY_PCI_POSSIBLE / 477 link->irq.possible_count; 478 } 479 480 return penalty; 481 } 482 483 static int acpi_irq_get_penalty(int irq) 484 { 485 int penalty = 0; 486 487 if (irq == sci_irq) 488 penalty += sci_penalty; 489 490 if (irq < ACPI_MAX_ISA_IRQS) 491 return penalty + acpi_isa_irq_penalty[irq]; 492 493 return penalty + acpi_irq_pci_sharing_penalty(irq); 494 } 495 496 int __init acpi_irq_penalty_init(void) 497 { 498 struct acpi_pci_link *link; 499 int i; 500 501 /* 502 * Update penalties to facilitate IRQ balancing. 503 */ 504 list_for_each_entry(link, &acpi_link_list, list) { 505 506 /* 507 * reflect the possible and active irqs in the penalty table -- 508 * useful for breaking ties. 509 */ 510 if (link->irq.possible_count) { 511 int penalty = 512 PIRQ_PENALTY_PCI_POSSIBLE / 513 link->irq.possible_count; 514 515 for (i = 0; i < link->irq.possible_count; i++) { 516 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS) 517 acpi_isa_irq_penalty[link->irq. 518 possible[i]] += 519 penalty; 520 } 521 522 } else if (link->irq.active && 523 (link->irq.active < ACPI_MAX_ISA_IRQS)) { 524 acpi_isa_irq_penalty[link->irq.active] += 525 PIRQ_PENALTY_PCI_POSSIBLE; 526 } 527 } 528 529 return 0; 530 } 531 532 static int acpi_irq_balance = -1; /* 0: static, 1: balance */ 533 534 static int acpi_pci_link_allocate(struct acpi_pci_link *link) 535 { 536 int irq; 537 int i; 538 539 if (link->irq.initialized) { 540 if (link->refcnt == 0) 541 /* This means the link is disabled but initialized */ 542 acpi_pci_link_set(link, link->irq.active); 543 return 0; 544 } 545 546 /* 547 * search for active IRQ in list of possible IRQs. 548 */ 549 for (i = 0; i < link->irq.possible_count; ++i) { 550 if (link->irq.active == link->irq.possible[i]) 551 break; 552 } 553 /* 554 * forget active IRQ that is not in possible list 555 */ 556 if (i == link->irq.possible_count) { 557 if (acpi_strict) 558 printk(KERN_WARNING PREFIX "_CRS %d not found" 559 " in _PRS\n", link->irq.active); 560 link->irq.active = 0; 561 } 562 563 /* 564 * if active found, use it; else pick entry from end of possible list. 565 */ 566 if (link->irq.active) 567 irq = link->irq.active; 568 else 569 irq = link->irq.possible[link->irq.possible_count - 1]; 570 571 if (acpi_irq_balance || !link->irq.active) { 572 /* 573 * Select the best IRQ. This is done in reverse to promote 574 * the use of IRQs 9, 10, 11, and >15. 575 */ 576 for (i = (link->irq.possible_count - 1); i >= 0; i--) { 577 if (acpi_irq_get_penalty(irq) > 578 acpi_irq_get_penalty(link->irq.possible[i])) 579 irq = link->irq.possible[i]; 580 } 581 } 582 if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) { 583 printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. " 584 "Try pci=noacpi or acpi=off\n", 585 acpi_device_name(link->device), 586 acpi_device_bid(link->device)); 587 return -ENODEV; 588 } 589 590 /* Attempt to enable the link device at this IRQ. */ 591 if (acpi_pci_link_set(link, irq)) { 592 printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. " 593 "Try pci=noacpi or acpi=off\n", 594 acpi_device_name(link->device), 595 acpi_device_bid(link->device)); 596 return -ENODEV; 597 } else { 598 if (link->irq.active < ACPI_MAX_ISA_IRQS) 599 acpi_isa_irq_penalty[link->irq.active] += 600 PIRQ_PENALTY_PCI_USING; 601 602 pr_info("%s [%s] enabled at IRQ %d\n", 603 acpi_device_name(link->device), 604 acpi_device_bid(link->device), link->irq.active); 605 } 606 607 link->irq.initialized = 1; 608 return 0; 609 } 610 611 /* 612 * acpi_pci_link_allocate_irq 613 * success: return IRQ >= 0 614 * failure: return -1 615 */ 616 int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering, 617 int *polarity, char **name) 618 { 619 int result; 620 struct acpi_device *device; 621 struct acpi_pci_link *link; 622 623 result = acpi_bus_get_device(handle, &device); 624 if (result) { 625 printk(KERN_ERR PREFIX "Invalid link device\n"); 626 return -1; 627 } 628 629 link = acpi_driver_data(device); 630 if (!link) { 631 printk(KERN_ERR PREFIX "Invalid link context\n"); 632 return -1; 633 } 634 635 /* TBD: Support multiple index (IRQ) entries per Link Device */ 636 if (index) { 637 printk(KERN_ERR PREFIX "Invalid index %d\n", index); 638 return -1; 639 } 640 641 mutex_lock(&acpi_link_lock); 642 if (acpi_pci_link_allocate(link)) { 643 mutex_unlock(&acpi_link_lock); 644 return -1; 645 } 646 647 if (!link->irq.active) { 648 mutex_unlock(&acpi_link_lock); 649 printk(KERN_ERR PREFIX "Link active IRQ is 0!\n"); 650 return -1; 651 } 652 link->refcnt++; 653 mutex_unlock(&acpi_link_lock); 654 655 if (triggering) 656 *triggering = link->irq.triggering; 657 if (polarity) 658 *polarity = link->irq.polarity; 659 if (name) 660 *name = acpi_device_bid(link->device); 661 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 662 "Link %s is referenced\n", 663 acpi_device_bid(link->device))); 664 return link->irq.active; 665 } 666 667 /* 668 * We don't change link's irq information here. After it is reenabled, we 669 * continue use the info 670 */ 671 int acpi_pci_link_free_irq(acpi_handle handle) 672 { 673 struct acpi_device *device; 674 struct acpi_pci_link *link; 675 acpi_status result; 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_evaluate_object(link->device->handle, "_DIS", NULL, 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 const struct acpi_device_id *not_used) 724 { 725 int result; 726 struct acpi_pci_link *link; 727 int i; 728 int found = 0; 729 730 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL); 731 if (!link) 732 return -ENOMEM; 733 734 link->device = device; 735 strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME); 736 strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS); 737 device->driver_data = link; 738 739 mutex_lock(&acpi_link_lock); 740 result = acpi_pci_link_get_possible(link); 741 if (result) 742 goto end; 743 744 /* query and set link->irq.active */ 745 acpi_pci_link_get_current(link); 746 747 printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device), 748 acpi_device_bid(device)); 749 for (i = 0; i < link->irq.possible_count; i++) { 750 if (link->irq.active == link->irq.possible[i]) { 751 printk(KERN_CONT " *%d", link->irq.possible[i]); 752 found = 1; 753 } else 754 printk(KERN_CONT " %d", link->irq.possible[i]); 755 } 756 757 printk(KERN_CONT ")"); 758 759 if (!found) 760 printk(KERN_CONT " *%d", link->irq.active); 761 762 if (!link->device->status.enabled) 763 printk(KERN_CONT ", disabled."); 764 765 printk(KERN_CONT "\n"); 766 767 list_add_tail(&link->list, &acpi_link_list); 768 769 end: 770 /* disable all links -- to be activated on use */ 771 acpi_evaluate_object(device->handle, "_DIS", NULL, NULL); 772 mutex_unlock(&acpi_link_lock); 773 774 if (result) 775 kfree(link); 776 777 return result < 0 ? result : 1; 778 } 779 780 static int acpi_pci_link_resume(struct acpi_pci_link *link) 781 { 782 if (link->refcnt && link->irq.active && link->irq.initialized) 783 return (acpi_pci_link_set(link, link->irq.active)); 784 785 return 0; 786 } 787 788 static void irqrouter_resume(void) 789 { 790 struct acpi_pci_link *link; 791 792 list_for_each_entry(link, &acpi_link_list, list) { 793 acpi_pci_link_resume(link); 794 } 795 } 796 797 static void acpi_pci_link_remove(struct acpi_device *device) 798 { 799 struct acpi_pci_link *link; 800 801 link = acpi_driver_data(device); 802 803 mutex_lock(&acpi_link_lock); 804 list_del(&link->list); 805 mutex_unlock(&acpi_link_lock); 806 807 kfree(link); 808 } 809 810 /* 811 * modify acpi_isa_irq_penalty[] from cmdline 812 */ 813 static int __init acpi_irq_penalty_update(char *str, int used) 814 { 815 int i; 816 817 for (i = 0; i < 16; i++) { 818 int retval; 819 int irq; 820 int new_penalty; 821 822 retval = get_option(&str, &irq); 823 824 if (!retval) 825 break; /* no number found */ 826 827 /* see if this is a ISA IRQ */ 828 if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS)) 829 continue; 830 831 if (used) 832 new_penalty = acpi_isa_irq_penalty[irq] + 833 PIRQ_PENALTY_ISA_USED; 834 else 835 new_penalty = 0; 836 837 acpi_isa_irq_penalty[irq] = new_penalty; 838 if (retval != 2) /* no next number */ 839 break; 840 } 841 return 1; 842 } 843 844 /* 845 * We'd like PNP to call this routine for the 846 * single ISA_USED value for each legacy device. 847 * But instead it calls us with each POSSIBLE setting. 848 * There is no ISA_POSSIBLE weight, so we simply use 849 * the (small) PCI_USING penalty. 850 */ 851 void acpi_penalize_isa_irq(int irq, int active) 852 { 853 if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty))) 854 acpi_isa_irq_penalty[irq] += 855 (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING); 856 } 857 858 bool acpi_isa_irq_available(int irq) 859 { 860 return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) || 861 acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS); 862 } 863 864 void acpi_penalize_sci_irq(int irq, int trigger, int polarity) 865 { 866 sci_irq = irq; 867 868 if (trigger == ACPI_MADT_TRIGGER_LEVEL && 869 polarity == ACPI_MADT_POLARITY_ACTIVE_LOW) 870 sci_penalty = PIRQ_PENALTY_PCI_USING; 871 else 872 sci_penalty = PIRQ_PENALTY_ISA_ALWAYS; 873 } 874 875 /* 876 * Over-ride default table to reserve additional IRQs for use by ISA 877 * e.g. acpi_irq_isa=5 878 * Useful for telling ACPI how not to interfere with your ISA sound card. 879 */ 880 static int __init acpi_irq_isa(char *str) 881 { 882 return acpi_irq_penalty_update(str, 1); 883 } 884 885 __setup("acpi_irq_isa=", acpi_irq_isa); 886 887 /* 888 * Over-ride default table to free additional IRQs for use by PCI 889 * e.g. acpi_irq_pci=7,15 890 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing. 891 */ 892 static int __init acpi_irq_pci(char *str) 893 { 894 return acpi_irq_penalty_update(str, 0); 895 } 896 897 __setup("acpi_irq_pci=", acpi_irq_pci); 898 899 static int __init acpi_irq_nobalance_set(char *str) 900 { 901 acpi_irq_balance = 0; 902 return 1; 903 } 904 905 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set); 906 907 static int __init acpi_irq_balance_set(char *str) 908 { 909 acpi_irq_balance = 1; 910 return 1; 911 } 912 913 __setup("acpi_irq_balance", acpi_irq_balance_set); 914 915 static struct syscore_ops irqrouter_syscore_ops = { 916 .resume = irqrouter_resume, 917 }; 918 919 void __init acpi_pci_link_init(void) 920 { 921 if (acpi_noirq) 922 return; 923 924 if (acpi_irq_balance == -1) { 925 /* no command line switch: enable balancing in IOAPIC mode */ 926 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC) 927 acpi_irq_balance = 1; 928 else 929 acpi_irq_balance = 0; 930 } 931 register_syscore_ops(&irqrouter_syscore_ops); 932 acpi_scan_add_handler(&pci_link_handler); 933 } 934