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