1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $) 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 * (c) Copyright 2008 Hewlett-Packard Development Company, L.P. 9 * Bjorn Helgaas <bjorn.helgaas@hp.com> 10 */ 11 12 13 #include <linux/dmi.h> 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/types.h> 18 #include <linux/spinlock.h> 19 #include <linux/pm.h> 20 #include <linux/pci.h> 21 #include <linux/acpi.h> 22 #include <linux/slab.h> 23 #include <linux/interrupt.h> 24 25 #define PREFIX "ACPI: " 26 27 #define _COMPONENT ACPI_PCI_COMPONENT 28 ACPI_MODULE_NAME("pci_irq"); 29 30 struct acpi_prt_entry { 31 struct acpi_pci_id id; 32 u8 pin; 33 acpi_handle link; 34 u32 index; /* GSI, or link _CRS index */ 35 }; 36 37 static inline char pin_name(int pin) 38 { 39 return 'A' + pin - 1; 40 } 41 42 /* -------------------------------------------------------------------------- 43 PCI IRQ Routing Table (PRT) Support 44 -------------------------------------------------------------------------- */ 45 46 /* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */ 47 static const struct dmi_system_id medion_md9580[] = { 48 { 49 .ident = "Medion MD9580-F laptop", 50 .matches = { 51 DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"), 52 DMI_MATCH(DMI_PRODUCT_NAME, "A555"), 53 }, 54 }, 55 { } 56 }; 57 58 /* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */ 59 static const struct dmi_system_id dell_optiplex[] = { 60 { 61 .ident = "Dell Optiplex GX1", 62 .matches = { 63 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), 64 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"), 65 }, 66 }, 67 { } 68 }; 69 70 /* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */ 71 static const struct dmi_system_id hp_t5710[] = { 72 { 73 .ident = "HP t5710", 74 .matches = { 75 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 76 DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"), 77 DMI_MATCH(DMI_BOARD_NAME, "098Ch"), 78 }, 79 }, 80 { } 81 }; 82 83 struct prt_quirk { 84 const struct dmi_system_id *system; 85 unsigned int segment; 86 unsigned int bus; 87 unsigned int device; 88 unsigned char pin; 89 const char *source; /* according to BIOS */ 90 const char *actual_source; 91 }; 92 93 #define PCI_INTX_PIN(c) (c - 'A' + 1) 94 95 /* 96 * These systems have incorrect _PRT entries. The BIOS claims the PCI 97 * interrupt at the listed segment/bus/device/pin is connected to the first 98 * link device, but it is actually connected to the second. 99 */ 100 static const struct prt_quirk prt_quirks[] = { 101 { medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'), 102 "\\_SB_.PCI0.ISA_.LNKA", 103 "\\_SB_.PCI0.ISA_.LNKB"}, 104 { dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'), 105 "\\_SB_.LNKB", 106 "\\_SB_.LNKA"}, 107 { hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'), 108 "\\_SB_.PCI0.LNK1", 109 "\\_SB_.PCI0.LNK3"}, 110 }; 111 112 static void do_prt_fixups(struct acpi_prt_entry *entry, 113 struct acpi_pci_routing_table *prt) 114 { 115 int i; 116 const struct prt_quirk *quirk; 117 118 for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) { 119 quirk = &prt_quirks[i]; 120 121 /* All current quirks involve link devices, not GSIs */ 122 if (dmi_check_system(quirk->system) && 123 entry->id.segment == quirk->segment && 124 entry->id.bus == quirk->bus && 125 entry->id.device == quirk->device && 126 entry->pin == quirk->pin && 127 !strcmp(prt->source, quirk->source) && 128 strlen(prt->source) >= strlen(quirk->actual_source)) { 129 printk(KERN_WARNING PREFIX "firmware reports " 130 "%04x:%02x:%02x PCI INT %c connected to %s; " 131 "changing to %s\n", 132 entry->id.segment, entry->id.bus, 133 entry->id.device, pin_name(entry->pin), 134 prt->source, quirk->actual_source); 135 strcpy(prt->source, quirk->actual_source); 136 } 137 } 138 } 139 140 static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev, 141 int pin, struct acpi_pci_routing_table *prt, 142 struct acpi_prt_entry **entry_ptr) 143 { 144 int segment = pci_domain_nr(dev->bus); 145 int bus = dev->bus->number; 146 int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn); 147 struct acpi_prt_entry *entry; 148 149 if (((prt->address >> 16) & 0xffff) != device || 150 prt->pin + 1 != pin) 151 return -ENODEV; 152 153 entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL); 154 if (!entry) 155 return -ENOMEM; 156 157 /* 158 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses 159 * 1=INTA, 2=INTB. We use the PCI encoding throughout, so convert 160 * it here. 161 */ 162 entry->id.segment = segment; 163 entry->id.bus = bus; 164 entry->id.device = (prt->address >> 16) & 0xFFFF; 165 entry->pin = prt->pin + 1; 166 167 do_prt_fixups(entry, prt); 168 169 entry->index = prt->source_index; 170 171 /* 172 * Type 1: Dynamic 173 * --------------- 174 * The 'source' field specifies the PCI interrupt link device used to 175 * configure the IRQ assigned to this slot|dev|pin. The 'source_index' 176 * indicates which resource descriptor in the resource template (of 177 * the link device) this interrupt is allocated from. 178 * 179 * NOTE: Don't query the Link Device for IRQ information at this time 180 * because Link Device enumeration may not have occurred yet 181 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI 182 * namespace). 183 */ 184 if (prt->source[0]) 185 acpi_get_handle(handle, prt->source, &entry->link); 186 187 /* 188 * Type 2: Static 189 * -------------- 190 * The 'source' field is NULL, and the 'source_index' field specifies 191 * the IRQ value, which is hardwired to specific interrupt inputs on 192 * the interrupt controller. 193 */ 194 195 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO, 196 " %04x:%02x:%02x[%c] -> %s[%d]\n", 197 entry->id.segment, entry->id.bus, 198 entry->id.device, pin_name(entry->pin), 199 prt->source, entry->index)); 200 201 *entry_ptr = entry; 202 203 return 0; 204 } 205 206 static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev, 207 int pin, struct acpi_prt_entry **entry_ptr) 208 { 209 acpi_status status; 210 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 211 struct acpi_pci_routing_table *entry; 212 acpi_handle handle = NULL; 213 214 if (dev->bus->bridge) 215 handle = ACPI_HANDLE(dev->bus->bridge); 216 217 if (!handle) 218 return -ENODEV; 219 220 /* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */ 221 status = acpi_get_irq_routing_table(handle, &buffer); 222 if (ACPI_FAILURE(status)) { 223 kfree(buffer.pointer); 224 return -ENODEV; 225 } 226 227 entry = buffer.pointer; 228 while (entry && (entry->length > 0)) { 229 if (!acpi_pci_irq_check_entry(handle, dev, pin, 230 entry, entry_ptr)) 231 break; 232 entry = (struct acpi_pci_routing_table *) 233 ((unsigned long)entry + entry->length); 234 } 235 236 kfree(buffer.pointer); 237 return 0; 238 } 239 240 /* -------------------------------------------------------------------------- 241 PCI Interrupt Routing Support 242 -------------------------------------------------------------------------- */ 243 #ifdef CONFIG_X86_IO_APIC 244 extern int noioapicquirk; 245 extern int noioapicreroute; 246 247 static int bridge_has_boot_interrupt_variant(struct pci_bus *bus) 248 { 249 struct pci_bus *bus_it; 250 251 for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) { 252 if (!bus_it->self) 253 return 0; 254 if (bus_it->self->irq_reroute_variant) 255 return bus_it->self->irq_reroute_variant; 256 } 257 return 0; 258 } 259 260 /* 261 * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ 262 * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does 263 * during interrupt handling). When this INTx generation cannot be disabled, 264 * we reroute these interrupts to their legacy equivalent to get rid of 265 * spurious interrupts. 266 */ 267 static int acpi_reroute_boot_interrupt(struct pci_dev *dev, 268 struct acpi_prt_entry *entry) 269 { 270 if (noioapicquirk || noioapicreroute) { 271 return 0; 272 } else { 273 switch (bridge_has_boot_interrupt_variant(dev->bus)) { 274 case 0: 275 /* no rerouting necessary */ 276 return 0; 277 case INTEL_IRQ_REROUTE_VARIANT: 278 /* 279 * Remap according to INTx routing table in 6700PXH 280 * specs, intel order number 302628-002, section 281 * 2.15.2. Other chipsets (80332, ...) have the same 282 * mapping and are handled here as well. 283 */ 284 dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy " 285 "IRQ %d\n", entry->index, 286 (entry->index % 4) + 16); 287 entry->index = (entry->index % 4) + 16; 288 return 1; 289 default: 290 dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy " 291 "IRQ: unknown mapping\n", entry->index); 292 return -1; 293 } 294 } 295 } 296 #endif /* CONFIG_X86_IO_APIC */ 297 298 static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin) 299 { 300 struct acpi_prt_entry *entry = NULL; 301 struct pci_dev *bridge; 302 u8 bridge_pin, orig_pin = pin; 303 int ret; 304 305 ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry); 306 if (!ret && entry) { 307 #ifdef CONFIG_X86_IO_APIC 308 acpi_reroute_boot_interrupt(dev, entry); 309 #endif /* CONFIG_X86_IO_APIC */ 310 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n", 311 pci_name(dev), pin_name(pin))); 312 return entry; 313 } 314 315 /* 316 * Attempt to derive an IRQ for this device from a parent bridge's 317 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge). 318 */ 319 bridge = dev->bus->self; 320 while (bridge) { 321 pin = pci_swizzle_interrupt_pin(dev, pin); 322 323 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) { 324 /* PC card has the same IRQ as its cardbridge */ 325 bridge_pin = bridge->pin; 326 if (!bridge_pin) { 327 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 328 "No interrupt pin configured for device %s\n", 329 pci_name(bridge))); 330 return NULL; 331 } 332 pin = bridge_pin; 333 } 334 335 ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry); 336 if (!ret && entry) { 337 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 338 "Derived GSI for %s INT %c from %s\n", 339 pci_name(dev), pin_name(orig_pin), 340 pci_name(bridge))); 341 return entry; 342 } 343 344 dev = bridge; 345 bridge = dev->bus->self; 346 } 347 348 dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n", 349 pin_name(orig_pin)); 350 return NULL; 351 } 352 353 #if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA) 354 static int acpi_isa_register_gsi(struct pci_dev *dev) 355 { 356 u32 dev_gsi; 357 358 /* Interrupt Line values above 0xF are forbidden */ 359 if (dev->irq > 0 && (dev->irq <= 0xF) && 360 acpi_isa_irq_available(dev->irq) && 361 (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) { 362 dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n", 363 pin_name(dev->pin), dev->irq); 364 acpi_register_gsi(&dev->dev, dev_gsi, 365 ACPI_LEVEL_SENSITIVE, 366 ACPI_ACTIVE_LOW); 367 return 0; 368 } 369 return -EINVAL; 370 } 371 #else 372 static inline int acpi_isa_register_gsi(struct pci_dev *dev) 373 { 374 return -ENODEV; 375 } 376 #endif 377 378 static inline bool acpi_pci_irq_valid(struct pci_dev *dev, u8 pin) 379 { 380 #ifdef CONFIG_X86 381 /* 382 * On x86 irq line 0xff means "unknown" or "no connection" 383 * (PCI 3.0, Section 6.2.4, footnote on page 223). 384 */ 385 if (dev->irq == 0xff) { 386 dev->irq = IRQ_NOTCONNECTED; 387 dev_warn(&dev->dev, "PCI INT %c: not connected\n", 388 pin_name(pin)); 389 return false; 390 } 391 #endif 392 return true; 393 } 394 395 int acpi_pci_irq_enable(struct pci_dev *dev) 396 { 397 struct acpi_prt_entry *entry; 398 int gsi; 399 u8 pin; 400 int triggering = ACPI_LEVEL_SENSITIVE; 401 /* 402 * On ARM systems with the GIC interrupt model, level interrupts 403 * are always polarity high by specification; PCI legacy 404 * IRQs lines are inverted before reaching the interrupt 405 * controller and must therefore be considered active high 406 * as default. 407 */ 408 int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ? 409 ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW; 410 char *link = NULL; 411 char link_desc[16]; 412 int rc; 413 414 pin = dev->pin; 415 if (!pin) { 416 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 417 "No interrupt pin configured for device %s\n", 418 pci_name(dev))); 419 return 0; 420 } 421 422 if (dev->irq_managed && dev->irq > 0) 423 return 0; 424 425 entry = acpi_pci_irq_lookup(dev, pin); 426 if (!entry) { 427 /* 428 * IDE legacy mode controller IRQs are magic. Why do compat 429 * extensions always make such a nasty mess. 430 */ 431 if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && 432 (dev->class & 0x05) == 0) 433 return 0; 434 } 435 436 if (entry) { 437 if (entry->link) 438 gsi = acpi_pci_link_allocate_irq(entry->link, 439 entry->index, 440 &triggering, &polarity, 441 &link); 442 else 443 gsi = entry->index; 444 } else 445 gsi = -1; 446 447 if (gsi < 0) { 448 /* 449 * No IRQ known to the ACPI subsystem - maybe the BIOS / 450 * driver reported one, then use it. Exit in any case. 451 */ 452 if (!acpi_pci_irq_valid(dev, pin)) { 453 kfree(entry); 454 return 0; 455 } 456 457 if (acpi_isa_register_gsi(dev)) 458 dev_warn(&dev->dev, "PCI INT %c: no GSI\n", 459 pin_name(pin)); 460 461 kfree(entry); 462 return 0; 463 } 464 465 rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity); 466 if (rc < 0) { 467 dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n", 468 pin_name(pin)); 469 kfree(entry); 470 return rc; 471 } 472 dev->irq = rc; 473 dev->irq_managed = 1; 474 475 if (link) 476 snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link); 477 else 478 link_desc[0] = '\0'; 479 480 dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n", 481 pin_name(pin), link_desc, gsi, 482 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge", 483 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq); 484 485 kfree(entry); 486 return 0; 487 } 488 489 void acpi_pci_irq_disable(struct pci_dev *dev) 490 { 491 struct acpi_prt_entry *entry; 492 int gsi; 493 u8 pin; 494 495 pin = dev->pin; 496 if (!pin || !dev->irq_managed || dev->irq <= 0) 497 return; 498 499 /* Keep IOAPIC pin configuration when suspending */ 500 if (dev->dev.power.is_prepared) 501 return; 502 #ifdef CONFIG_PM 503 if (dev->dev.power.runtime_status == RPM_SUSPENDING) 504 return; 505 #endif 506 507 entry = acpi_pci_irq_lookup(dev, pin); 508 if (!entry) 509 return; 510 511 if (entry->link) 512 gsi = acpi_pci_link_free_irq(entry->link); 513 else 514 gsi = entry->index; 515 516 kfree(entry); 517 518 /* 519 * TBD: It might be worth clearing dev->irq by magic constant 520 * (e.g. PCI_UNDEFINED_IRQ). 521 */ 522 523 dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin)); 524 if (gsi >= 0) { 525 acpi_unregister_gsi(gsi); 526 dev->irq_managed = 0; 527 } 528 } 529