1 /* 2 * pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $) 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de> 7 * 8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or (at 13 * your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, but 16 * WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License along 21 * with this program; if not, write to the Free Software Foundation, Inc., 22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 23 * 24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 25 */ 26 27 28 #include <linux/kernel.h> 29 #include <linux/module.h> 30 #include <linux/init.h> 31 #include <linux/types.h> 32 #include <linux/proc_fs.h> 33 #include <linux/spinlock.h> 34 #include <linux/pm.h> 35 #include <linux/pci.h> 36 #include <linux/acpi.h> 37 #include <acpi/acpi_bus.h> 38 #include <acpi/acpi_drivers.h> 39 40 #define _COMPONENT ACPI_PCI_COMPONENT 41 ACPI_MODULE_NAME("pci_irq"); 42 43 static struct acpi_prt_list acpi_prt; 44 static DEFINE_SPINLOCK(acpi_prt_lock); 45 46 /* -------------------------------------------------------------------------- 47 PCI IRQ Routing Table (PRT) Support 48 -------------------------------------------------------------------------- */ 49 50 static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(int segment, 51 int bus, 52 int device, int pin) 53 { 54 struct list_head *node = NULL; 55 struct acpi_prt_entry *entry = NULL; 56 57 58 if (!acpi_prt.count) 59 return NULL; 60 61 /* 62 * Parse through all PRT entries looking for a match on the specified 63 * PCI device's segment, bus, device, and pin (don't care about func). 64 * 65 */ 66 spin_lock(&acpi_prt_lock); 67 list_for_each(node, &acpi_prt.entries) { 68 entry = list_entry(node, struct acpi_prt_entry, node); 69 if ((segment == entry->id.segment) 70 && (bus == entry->id.bus) 71 && (device == entry->id.device) 72 && (pin == entry->pin)) { 73 spin_unlock(&acpi_prt_lock); 74 return entry; 75 } 76 } 77 78 spin_unlock(&acpi_prt_lock); 79 return NULL; 80 } 81 82 static int 83 acpi_pci_irq_add_entry(acpi_handle handle, 84 int segment, int bus, struct acpi_pci_routing_table *prt) 85 { 86 struct acpi_prt_entry *entry = NULL; 87 88 89 if (!prt) 90 return -EINVAL; 91 92 entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL); 93 if (!entry) 94 return -ENOMEM; 95 96 entry->id.segment = segment; 97 entry->id.bus = bus; 98 entry->id.device = (prt->address >> 16) & 0xFFFF; 99 entry->id.function = prt->address & 0xFFFF; 100 entry->pin = prt->pin; 101 102 /* 103 * Type 1: Dynamic 104 * --------------- 105 * The 'source' field specifies the PCI interrupt link device used to 106 * configure the IRQ assigned to this slot|dev|pin. The 'source_index' 107 * indicates which resource descriptor in the resource template (of 108 * the link device) this interrupt is allocated from. 109 * 110 * NOTE: Don't query the Link Device for IRQ information at this time 111 * because Link Device enumeration may not have occurred yet 112 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI 113 * namespace). 114 */ 115 if (prt->source[0]) { 116 acpi_get_handle(handle, prt->source, &entry->link.handle); 117 entry->link.index = prt->source_index; 118 } 119 /* 120 * Type 2: Static 121 * -------------- 122 * The 'source' field is NULL, and the 'source_index' field specifies 123 * the IRQ value, which is hardwired to specific interrupt inputs on 124 * the interrupt controller. 125 */ 126 else 127 entry->link.index = prt->source_index; 128 129 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO, 130 " %02X:%02X:%02X[%c] -> %s[%d]\n", 131 entry->id.segment, entry->id.bus, 132 entry->id.device, ('A' + entry->pin), prt->source, 133 entry->link.index)); 134 135 spin_lock(&acpi_prt_lock); 136 list_add_tail(&entry->node, &acpi_prt.entries); 137 acpi_prt.count++; 138 spin_unlock(&acpi_prt_lock); 139 140 return 0; 141 } 142 143 static void 144 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry) 145 { 146 if (segment == entry->id.segment && bus == entry->id.bus) { 147 acpi_prt.count--; 148 list_del(&entry->node); 149 kfree(entry); 150 } 151 } 152 153 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus) 154 { 155 acpi_status status = AE_OK; 156 char *pathname = NULL; 157 struct acpi_buffer buffer = { 0, NULL }; 158 struct acpi_pci_routing_table *prt = NULL; 159 struct acpi_pci_routing_table *entry = NULL; 160 static int first_time = 1; 161 162 163 pathname = kzalloc(ACPI_PATHNAME_MAX, GFP_KERNEL); 164 if (!pathname) 165 return -ENOMEM; 166 167 if (first_time) { 168 acpi_prt.count = 0; 169 INIT_LIST_HEAD(&acpi_prt.entries); 170 first_time = 0; 171 } 172 173 /* 174 * NOTE: We're given a 'handle' to the _PRT object's parent device 175 * (either a PCI root bridge or PCI-PCI bridge). 176 */ 177 178 buffer.length = ACPI_PATHNAME_MAX; 179 buffer.pointer = pathname; 180 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 181 182 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n", 183 pathname); 184 185 /* 186 * Evaluate this _PRT and add its entries to our global list (acpi_prt). 187 */ 188 189 buffer.length = 0; 190 buffer.pointer = NULL; 191 kfree(pathname); 192 status = acpi_get_irq_routing_table(handle, &buffer); 193 if (status != AE_BUFFER_OVERFLOW) { 194 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]", 195 acpi_format_exception(status))); 196 return -ENODEV; 197 } 198 199 prt = kzalloc(buffer.length, GFP_KERNEL); 200 if (!prt) { 201 return -ENOMEM; 202 } 203 buffer.pointer = prt; 204 205 status = acpi_get_irq_routing_table(handle, &buffer); 206 if (ACPI_FAILURE(status)) { 207 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]", 208 acpi_format_exception(status))); 209 kfree(buffer.pointer); 210 return -ENODEV; 211 } 212 213 entry = prt; 214 215 while (entry && (entry->length > 0)) { 216 acpi_pci_irq_add_entry(handle, segment, bus, entry); 217 entry = (struct acpi_pci_routing_table *) 218 ((unsigned long)entry + entry->length); 219 } 220 221 kfree(prt); 222 223 return 0; 224 } 225 226 void acpi_pci_irq_del_prt(int segment, int bus) 227 { 228 struct list_head *node = NULL, *n = NULL; 229 struct acpi_prt_entry *entry = NULL; 230 231 if (!acpi_prt.count) { 232 return; 233 } 234 235 printk(KERN_DEBUG 236 "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment, 237 bus); 238 spin_lock(&acpi_prt_lock); 239 list_for_each_safe(node, n, &acpi_prt.entries) { 240 entry = list_entry(node, struct acpi_prt_entry, node); 241 242 acpi_pci_irq_del_entry(segment, bus, entry); 243 } 244 spin_unlock(&acpi_prt_lock); 245 } 246 247 /* -------------------------------------------------------------------------- 248 PCI Interrupt Routing Support 249 -------------------------------------------------------------------------- */ 250 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **); 251 252 static int 253 acpi_pci_allocate_irq(struct acpi_prt_entry *entry, 254 int *triggering, int *polarity, char **link) 255 { 256 int irq; 257 258 259 if (entry->link.handle) { 260 irq = acpi_pci_link_allocate_irq(entry->link.handle, 261 entry->link.index, triggering, 262 polarity, link); 263 if (irq < 0) { 264 printk(KERN_WARNING PREFIX 265 "Invalid IRQ link routing entry\n"); 266 return -1; 267 } 268 } else { 269 irq = entry->link.index; 270 *triggering = ACPI_LEVEL_SENSITIVE; 271 *polarity = ACPI_ACTIVE_LOW; 272 } 273 274 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq)); 275 return irq; 276 } 277 278 static int 279 acpi_pci_free_irq(struct acpi_prt_entry *entry, 280 int *triggering, int *polarity, char **link) 281 { 282 int irq; 283 284 if (entry->link.handle) { 285 irq = acpi_pci_link_free_irq(entry->link.handle); 286 } else { 287 irq = entry->link.index; 288 } 289 return irq; 290 } 291 292 /* 293 * acpi_pci_irq_lookup 294 * success: return IRQ >= 0 295 * failure: return -1 296 */ 297 static int 298 acpi_pci_irq_lookup(struct pci_bus *bus, 299 int device, 300 int pin, 301 int *triggering, 302 int *polarity, char **link, irq_lookup_func func) 303 { 304 struct acpi_prt_entry *entry = NULL; 305 int segment = pci_domain_nr(bus); 306 int bus_nr = bus->number; 307 int ret; 308 309 310 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 311 "Searching for PRT entry for %02x:%02x:%02x[%c]\n", 312 segment, bus_nr, device, ('A' + pin))); 313 314 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin); 315 if (!entry) { 316 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n")); 317 return -1; 318 } 319 320 ret = func(entry, triggering, polarity, link); 321 return ret; 322 } 323 324 /* 325 * acpi_pci_irq_derive 326 * success: return IRQ >= 0 327 * failure: return < 0 328 */ 329 static int 330 acpi_pci_irq_derive(struct pci_dev *dev, 331 int pin, 332 int *triggering, 333 int *polarity, char **link, irq_lookup_func func) 334 { 335 struct pci_dev *bridge = dev; 336 int irq = -1; 337 u8 bridge_pin = 0; 338 339 340 if (!dev) 341 return -EINVAL; 342 343 /* 344 * Attempt to derive an IRQ for this device from a parent bridge's 345 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge). 346 */ 347 while (irq < 0 && bridge->bus->self) { 348 pin = (pin + PCI_SLOT(bridge->devfn)) % 4; 349 bridge = bridge->bus->self; 350 351 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) { 352 /* PC card has the same IRQ as its cardbridge */ 353 bridge_pin = bridge->pin; 354 if (!bridge_pin) { 355 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 356 "No interrupt pin configured for device %s\n", 357 pci_name(bridge))); 358 return -1; 359 } 360 /* Pin is from 0 to 3 */ 361 bridge_pin--; 362 pin = bridge_pin; 363 } 364 365 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn), 366 pin, triggering, polarity, 367 link, func); 368 } 369 370 if (irq < 0) { 371 printk(KERN_WARNING PREFIX "Unable to derive IRQ for device %s\n", 372 pci_name(dev)); 373 return -1; 374 } 375 376 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n", 377 irq, pci_name(dev), pci_name(bridge))); 378 379 return irq; 380 } 381 382 /* 383 * acpi_pci_irq_enable 384 * success: return 0 385 * failure: return < 0 386 */ 387 388 int acpi_pci_irq_enable(struct pci_dev *dev) 389 { 390 int irq = 0; 391 u8 pin = 0; 392 int triggering = ACPI_LEVEL_SENSITIVE; 393 int polarity = ACPI_ACTIVE_LOW; 394 char *link = NULL; 395 int rc; 396 397 398 if (!dev) 399 return -EINVAL; 400 401 pin = dev->pin; 402 if (!pin) { 403 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 404 "No interrupt pin configured for device %s\n", 405 pci_name(dev))); 406 return 0; 407 } 408 pin--; 409 410 if (!dev->bus) { 411 printk(KERN_ERR PREFIX "Invalid (NULL) 'bus' field\n"); 412 return -ENODEV; 413 } 414 415 /* 416 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT 417 * values override any BIOS-assigned IRQs set during boot. 418 */ 419 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 420 &triggering, &polarity, &link, 421 acpi_pci_allocate_irq); 422 423 /* 424 * If no PRT entry was found, we'll try to derive an IRQ from the 425 * device's parent bridge. 426 */ 427 if (irq < 0) 428 irq = acpi_pci_irq_derive(dev, pin, &triggering, 429 &polarity, &link, 430 acpi_pci_allocate_irq); 431 432 if (irq < 0) { 433 /* 434 * IDE legacy mode controller IRQs are magic. Why do compat 435 * extensions always make such a nasty mess. 436 */ 437 if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && 438 (dev->class & 0x05) == 0) 439 return 0; 440 } 441 /* 442 * No IRQ known to the ACPI subsystem - maybe the BIOS / 443 * driver reported one, then use it. Exit in any case. 444 */ 445 if (irq < 0) { 446 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI", 447 pci_name(dev), ('A' + pin)); 448 /* Interrupt Line values above 0xF are forbidden */ 449 if (dev->irq > 0 && (dev->irq <= 0xF)) { 450 printk(" - using IRQ %d\n", dev->irq); 451 acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE, 452 ACPI_ACTIVE_LOW); 453 return 0; 454 } else { 455 printk("\n"); 456 return 0; 457 } 458 } 459 460 rc = acpi_register_gsi(irq, triggering, polarity); 461 if (rc < 0) { 462 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed " 463 "to register GSI\n", pci_name(dev), ('A' + pin)); 464 return rc; 465 } 466 dev->irq = rc; 467 468 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ", 469 pci_name(dev), 'A' + pin); 470 471 if (link) 472 printk("Link [%s] -> ", link); 473 474 printk("GSI %u (%s, %s) -> IRQ %d\n", irq, 475 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge", 476 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq); 477 478 return 0; 479 } 480 481 EXPORT_SYMBOL(acpi_pci_irq_enable); 482 483 /* FIXME: implement x86/x86_64 version */ 484 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i) 485 { 486 } 487 488 void acpi_pci_irq_disable(struct pci_dev *dev) 489 { 490 int gsi = 0; 491 u8 pin = 0; 492 int triggering = ACPI_LEVEL_SENSITIVE; 493 int polarity = ACPI_ACTIVE_LOW; 494 495 496 if (!dev || !dev->bus) 497 return; 498 499 pin = dev->pin; 500 if (!pin) 501 return; 502 pin--; 503 504 /* 505 * First we check the PCI IRQ routing table (PRT) for an IRQ. 506 */ 507 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 508 &triggering, &polarity, NULL, 509 acpi_pci_free_irq); 510 /* 511 * If no PRT entry was found, we'll try to derive an IRQ from the 512 * device's parent bridge. 513 */ 514 if (gsi < 0) 515 gsi = acpi_pci_irq_derive(dev, pin, 516 &triggering, &polarity, NULL, 517 acpi_pci_free_irq); 518 if (gsi < 0) 519 return; 520 521 /* 522 * TBD: It might be worth clearing dev->irq by magic constant 523 * (e.g. PCI_UNDEFINED_IRQ). 524 */ 525 526 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n", 527 pci_name(dev)); 528 529 acpi_unregister_gsi(gsi); 530 531 return; 532 } 533