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 #include <linux/config.h> 28 29 #include <linux/kernel.h> 30 #include <linux/module.h> 31 #include <linux/init.h> 32 #include <linux/types.h> 33 #include <linux/proc_fs.h> 34 #include <linux/spinlock.h> 35 #include <linux/pm.h> 36 #include <linux/pci.h> 37 #include <linux/acpi.h> 38 #include <acpi/acpi_bus.h> 39 #include <acpi/acpi_drivers.h> 40 41 #define _COMPONENT ACPI_PCI_COMPONENT 42 ACPI_MODULE_NAME("pci_irq") 43 44 static struct acpi_prt_list acpi_prt; 45 static DEFINE_SPINLOCK(acpi_prt_lock); 46 47 /* -------------------------------------------------------------------------- 48 PCI IRQ Routing Table (PRT) Support 49 -------------------------------------------------------------------------- */ 50 51 static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(int segment, 52 int bus, 53 int device, int pin) 54 { 55 struct list_head *node = NULL; 56 struct acpi_prt_entry *entry = NULL; 57 58 ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry"); 59 60 if (!acpi_prt.count) 61 return_PTR(NULL); 62 63 /* 64 * Parse through all PRT entries looking for a match on the specified 65 * PCI device's segment, bus, device, and pin (don't care about func). 66 * 67 */ 68 spin_lock(&acpi_prt_lock); 69 list_for_each(node, &acpi_prt.entries) { 70 entry = list_entry(node, struct acpi_prt_entry, node); 71 if ((segment == entry->id.segment) 72 && (bus == entry->id.bus) 73 && (device == entry->id.device) 74 && (pin == entry->pin)) { 75 spin_unlock(&acpi_prt_lock); 76 return_PTR(entry); 77 } 78 } 79 80 spin_unlock(&acpi_prt_lock); 81 return_PTR(NULL); 82 } 83 84 static int 85 acpi_pci_irq_add_entry(acpi_handle handle, 86 int segment, int bus, struct acpi_pci_routing_table *prt) 87 { 88 struct acpi_prt_entry *entry = NULL; 89 90 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry"); 91 92 if (!prt) 93 return_VALUE(-EINVAL); 94 95 entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL); 96 if (!entry) 97 return_VALUE(-ENOMEM); 98 memset(entry, 0, sizeof(struct acpi_prt_entry)); 99 100 entry->id.segment = segment; 101 entry->id.bus = bus; 102 entry->id.device = (prt->address >> 16) & 0xFFFF; 103 entry->id.function = prt->address & 0xFFFF; 104 entry->pin = prt->pin; 105 106 /* 107 * Type 1: Dynamic 108 * --------------- 109 * The 'source' field specifies the PCI interrupt link device used to 110 * configure the IRQ assigned to this slot|dev|pin. The 'source_index' 111 * indicates which resource descriptor in the resource template (of 112 * the link device) this interrupt is allocated from. 113 * 114 * NOTE: Don't query the Link Device for IRQ information at this time 115 * because Link Device enumeration may not have occurred yet 116 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI 117 * namespace). 118 */ 119 if (prt->source[0]) { 120 acpi_get_handle(handle, prt->source, &entry->link.handle); 121 entry->link.index = prt->source_index; 122 } 123 /* 124 * Type 2: Static 125 * -------------- 126 * The 'source' field is NULL, and the 'source_index' field specifies 127 * the IRQ value, which is hardwired to specific interrupt inputs on 128 * the interrupt controller. 129 */ 130 else 131 entry->link.index = prt->source_index; 132 133 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO, 134 " %02X:%02X:%02X[%c] -> %s[%d]\n", 135 entry->id.segment, entry->id.bus, 136 entry->id.device, ('A' + entry->pin), prt->source, 137 entry->link.index)); 138 139 spin_lock(&acpi_prt_lock); 140 list_add_tail(&entry->node, &acpi_prt.entries); 141 acpi_prt.count++; 142 spin_unlock(&acpi_prt_lock); 143 144 return_VALUE(0); 145 } 146 147 static void 148 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry) 149 { 150 if (segment == entry->id.segment && bus == entry->id.bus) { 151 acpi_prt.count--; 152 list_del(&entry->node); 153 kfree(entry); 154 } 155 } 156 157 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus) 158 { 159 acpi_status status = AE_OK; 160 char *pathname = NULL; 161 struct acpi_buffer buffer = { 0, NULL }; 162 struct acpi_pci_routing_table *prt = NULL; 163 struct acpi_pci_routing_table *entry = NULL; 164 static int first_time = 1; 165 166 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt"); 167 168 pathname = (char *)kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL); 169 if (!pathname) 170 return_VALUE(-ENOMEM); 171 memset(pathname, 0, ACPI_PATHNAME_MAX); 172 173 if (first_time) { 174 acpi_prt.count = 0; 175 INIT_LIST_HEAD(&acpi_prt.entries); 176 first_time = 0; 177 } 178 179 /* 180 * NOTE: We're given a 'handle' to the _PRT object's parent device 181 * (either a PCI root bridge or PCI-PCI bridge). 182 */ 183 184 buffer.length = ACPI_PATHNAME_MAX; 185 buffer.pointer = pathname; 186 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 187 188 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n", 189 pathname); 190 191 /* 192 * Evaluate this _PRT and add its entries to our global list (acpi_prt). 193 */ 194 195 buffer.length = 0; 196 buffer.pointer = NULL; 197 kfree(pathname); 198 status = acpi_get_irq_routing_table(handle, &buffer); 199 if (status != AE_BUFFER_OVERFLOW) { 200 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n", 201 acpi_format_exception(status))); 202 return_VALUE(-ENODEV); 203 } 204 205 prt = kmalloc(buffer.length, GFP_KERNEL); 206 if (!prt) { 207 return_VALUE(-ENOMEM); 208 } 209 memset(prt, 0, buffer.length); 210 buffer.pointer = prt; 211 212 status = acpi_get_irq_routing_table(handle, &buffer); 213 if (ACPI_FAILURE(status)) { 214 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n", 215 acpi_format_exception(status))); 216 kfree(buffer.pointer); 217 return_VALUE(-ENODEV); 218 } 219 220 entry = prt; 221 222 while (entry && (entry->length > 0)) { 223 acpi_pci_irq_add_entry(handle, segment, bus, entry); 224 entry = (struct acpi_pci_routing_table *) 225 ((unsigned long)entry + entry->length); 226 } 227 228 kfree(prt); 229 230 return_VALUE(0); 231 } 232 233 void acpi_pci_irq_del_prt(int segment, int bus) 234 { 235 struct list_head *node = NULL, *n = NULL; 236 struct acpi_prt_entry *entry = NULL; 237 238 if (!acpi_prt.count) { 239 return; 240 } 241 242 printk(KERN_DEBUG 243 "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment, 244 bus); 245 spin_lock(&acpi_prt_lock); 246 list_for_each_safe(node, n, &acpi_prt.entries) { 247 entry = list_entry(node, struct acpi_prt_entry, node); 248 249 acpi_pci_irq_del_entry(segment, bus, entry); 250 } 251 spin_unlock(&acpi_prt_lock); 252 } 253 254 /* -------------------------------------------------------------------------- 255 PCI Interrupt Routing Support 256 -------------------------------------------------------------------------- */ 257 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **); 258 259 static int 260 acpi_pci_allocate_irq(struct acpi_prt_entry *entry, 261 int *edge_level, int *active_high_low, char **link) 262 { 263 int irq; 264 265 ACPI_FUNCTION_TRACE("acpi_pci_allocate_irq"); 266 267 if (entry->link.handle) { 268 irq = acpi_pci_link_allocate_irq(entry->link.handle, 269 entry->link.index, edge_level, 270 active_high_low, link); 271 if (irq < 0) { 272 ACPI_DEBUG_PRINT((ACPI_DB_WARN, 273 "Invalid IRQ link routing entry\n")); 274 return_VALUE(-1); 275 } 276 } else { 277 irq = entry->link.index; 278 *edge_level = ACPI_LEVEL_SENSITIVE; 279 *active_high_low = ACPI_ACTIVE_LOW; 280 } 281 282 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq)); 283 return_VALUE(irq); 284 } 285 286 static int 287 acpi_pci_free_irq(struct acpi_prt_entry *entry, 288 int *edge_level, int *active_high_low, char **link) 289 { 290 int irq; 291 292 ACPI_FUNCTION_TRACE("acpi_pci_free_irq"); 293 if (entry->link.handle) { 294 irq = acpi_pci_link_free_irq(entry->link.handle); 295 } else { 296 irq = entry->link.index; 297 } 298 return_VALUE(irq); 299 } 300 301 /* 302 * acpi_pci_irq_lookup 303 * success: return IRQ >= 0 304 * failure: return -1 305 */ 306 static int 307 acpi_pci_irq_lookup(struct pci_bus *bus, 308 int device, 309 int pin, 310 int *edge_level, 311 int *active_high_low, char **link, irq_lookup_func func) 312 { 313 struct acpi_prt_entry *entry = NULL; 314 int segment = pci_domain_nr(bus); 315 int bus_nr = bus->number; 316 int ret; 317 318 ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup"); 319 320 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 321 "Searching for PRT entry for %02x:%02x:%02x[%c]\n", 322 segment, bus_nr, device, ('A' + pin))); 323 324 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin); 325 if (!entry) { 326 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n")); 327 return_VALUE(-1); 328 } 329 330 ret = func(entry, edge_level, active_high_low, link); 331 return_VALUE(ret); 332 } 333 334 /* 335 * acpi_pci_irq_derive 336 * success: return IRQ >= 0 337 * failure: return < 0 338 */ 339 static int 340 acpi_pci_irq_derive(struct pci_dev *dev, 341 int pin, 342 int *edge_level, 343 int *active_high_low, char **link, irq_lookup_func func) 344 { 345 struct pci_dev *bridge = dev; 346 int irq = -1; 347 u8 bridge_pin = 0; 348 349 ACPI_FUNCTION_TRACE("acpi_pci_irq_derive"); 350 351 if (!dev) 352 return_VALUE(-EINVAL); 353 354 /* 355 * Attempt to derive an IRQ for this device from a parent bridge's 356 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge). 357 */ 358 while (irq < 0 && bridge->bus->self) { 359 pin = (pin + PCI_SLOT(bridge->devfn)) % 4; 360 bridge = bridge->bus->self; 361 362 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) { 363 /* PC card has the same IRQ as its cardbridge */ 364 bridge_pin = bridge->pin; 365 if (!bridge_pin) { 366 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 367 "No interrupt pin configured for device %s\n", 368 pci_name(bridge))); 369 return_VALUE(-1); 370 } 371 /* Pin is from 0 to 3 */ 372 bridge_pin--; 373 pin = bridge_pin; 374 } 375 376 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn), 377 pin, edge_level, active_high_low, 378 link, func); 379 } 380 381 if (irq < 0) { 382 ACPI_DEBUG_PRINT((ACPI_DB_WARN, 383 "Unable to derive IRQ for device %s\n", 384 pci_name(dev))); 385 return_VALUE(-1); 386 } 387 388 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n", 389 irq, pci_name(dev), pci_name(bridge))); 390 391 return_VALUE(irq); 392 } 393 394 /* 395 * acpi_pci_irq_enable 396 * success: return 0 397 * failure: return < 0 398 */ 399 400 int acpi_pci_irq_enable(struct pci_dev *dev) 401 { 402 int irq = 0; 403 u8 pin = 0; 404 int edge_level = ACPI_LEVEL_SENSITIVE; 405 int active_high_low = ACPI_ACTIVE_LOW; 406 char *link = NULL; 407 int rc; 408 409 ACPI_FUNCTION_TRACE("acpi_pci_irq_enable"); 410 411 if (!dev) 412 return_VALUE(-EINVAL); 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_VALUE(0); 420 } 421 pin--; 422 423 if (!dev->bus) { 424 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 425 "Invalid (NULL) 'bus' field\n")); 426 return_VALUE(-ENODEV); 427 } 428 429 /* 430 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT 431 * values override any BIOS-assigned IRQs set during boot. 432 */ 433 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 434 &edge_level, &active_high_low, &link, 435 acpi_pci_allocate_irq); 436 437 /* 438 * If no PRT entry was found, we'll try to derive an IRQ from the 439 * device's parent bridge. 440 */ 441 if (irq < 0) 442 irq = acpi_pci_irq_derive(dev, pin, &edge_level, 443 &active_high_low, &link, 444 acpi_pci_allocate_irq); 445 446 /* 447 * No IRQ known to the ACPI subsystem - maybe the BIOS / 448 * driver reported one, then use it. Exit in any case. 449 */ 450 if (irq < 0) { 451 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI", 452 pci_name(dev), ('A' + pin)); 453 /* Interrupt Line values above 0xF are forbidden */ 454 if (dev->irq > 0 && (dev->irq <= 0xF)) { 455 printk(" - using IRQ %d\n", dev->irq); 456 acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE, 457 ACPI_ACTIVE_LOW); 458 return_VALUE(0); 459 } else { 460 printk("\n"); 461 return_VALUE(0); 462 } 463 } 464 465 rc = acpi_register_gsi(irq, edge_level, active_high_low); 466 if (rc < 0) { 467 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed " 468 "to register GSI\n", pci_name(dev), ('A' + pin)); 469 return_VALUE(rc); 470 } 471 dev->irq = rc; 472 473 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ", 474 pci_name(dev), 'A' + pin); 475 476 if (link) 477 printk("Link [%s] -> ", link); 478 479 printk("GSI %u (%s, %s) -> IRQ %d\n", irq, 480 (edge_level == ACPI_LEVEL_SENSITIVE) ? "level" : "edge", 481 (active_high_low == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq); 482 483 return_VALUE(0); 484 } 485 486 EXPORT_SYMBOL(acpi_pci_irq_enable); 487 488 /* FIXME: implement x86/x86_64 version */ 489 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i) 490 { 491 } 492 493 void acpi_pci_irq_disable(struct pci_dev *dev) 494 { 495 int gsi = 0; 496 u8 pin = 0; 497 int edge_level = ACPI_LEVEL_SENSITIVE; 498 int active_high_low = ACPI_ACTIVE_LOW; 499 500 ACPI_FUNCTION_TRACE("acpi_pci_irq_disable"); 501 502 if (!dev || !dev->bus) 503 return_VOID; 504 505 pin = dev->pin; 506 if (!pin) 507 return_VOID; 508 pin--; 509 510 /* 511 * First we check the PCI IRQ routing table (PRT) for an IRQ. 512 */ 513 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 514 &edge_level, &active_high_low, NULL, 515 acpi_pci_free_irq); 516 /* 517 * If no PRT entry was found, we'll try to derive an IRQ from the 518 * device's parent bridge. 519 */ 520 if (gsi < 0) 521 gsi = acpi_pci_irq_derive(dev, pin, 522 &edge_level, &active_high_low, NULL, 523 acpi_pci_free_irq); 524 if (gsi < 0) 525 return_VOID; 526 527 /* 528 * TBD: It might be worth clearing dev->irq by magic constant 529 * (e.g. PCI_UNDEFINED_IRQ). 530 */ 531 532 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n", 533 pci_name(dev)); 534 535 acpi_unregister_gsi(gsi); 536 537 return_VOID; 538 } 539