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 42 #define _COMPONENT ACPI_PCI_COMPONENT 43 ACPI_MODULE_NAME ("pci_irq") 44 45 static struct acpi_prt_list acpi_prt; 46 static DEFINE_SPINLOCK(acpi_prt_lock); 47 48 /* -------------------------------------------------------------------------- 49 PCI IRQ Routing Table (PRT) Support 50 -------------------------------------------------------------------------- */ 51 52 static struct acpi_prt_entry * 53 acpi_pci_irq_find_prt_entry ( 54 int segment, 55 int bus, 56 int device, 57 int pin) 58 { 59 struct list_head *node = NULL; 60 struct acpi_prt_entry *entry = NULL; 61 62 ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry"); 63 64 if (!acpi_prt.count) 65 return_PTR(NULL); 66 67 /* 68 * Parse through all PRT entries looking for a match on the specified 69 * PCI device's segment, bus, device, and pin (don't care about func). 70 * 71 */ 72 spin_lock(&acpi_prt_lock); 73 list_for_each(node, &acpi_prt.entries) { 74 entry = list_entry(node, struct acpi_prt_entry, node); 75 if ((segment == entry->id.segment) 76 && (bus == entry->id.bus) 77 && (device == entry->id.device) 78 && (pin == entry->pin)) { 79 spin_unlock(&acpi_prt_lock); 80 return_PTR(entry); 81 } 82 } 83 84 spin_unlock(&acpi_prt_lock); 85 return_PTR(NULL); 86 } 87 88 89 static int 90 acpi_pci_irq_add_entry ( 91 acpi_handle handle, 92 int segment, 93 int bus, 94 struct acpi_pci_routing_table *prt) 95 { 96 struct acpi_prt_entry *entry = NULL; 97 98 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry"); 99 100 if (!prt) 101 return_VALUE(-EINVAL); 102 103 entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL); 104 if (!entry) 105 return_VALUE(-ENOMEM); 106 memset(entry, 0, sizeof(struct acpi_prt_entry)); 107 108 entry->id.segment = segment; 109 entry->id.bus = bus; 110 entry->id.device = (prt->address >> 16) & 0xFFFF; 111 entry->id.function = prt->address & 0xFFFF; 112 entry->pin = prt->pin; 113 114 /* 115 * Type 1: Dynamic 116 * --------------- 117 * The 'source' field specifies the PCI interrupt link device used to 118 * configure the IRQ assigned to this slot|dev|pin. The 'source_index' 119 * indicates which resource descriptor in the resource template (of 120 * the link device) this interrupt is allocated from. 121 * 122 * NOTE: Don't query the Link Device for IRQ information at this time 123 * because Link Device enumeration may not have occurred yet 124 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI 125 * namespace). 126 */ 127 if (prt->source[0]) { 128 acpi_get_handle(handle, prt->source, &entry->link.handle); 129 entry->link.index = prt->source_index; 130 } 131 /* 132 * Type 2: Static 133 * -------------- 134 * The 'source' field is NULL, and the 'source_index' field specifies 135 * the IRQ value, which is hardwired to specific interrupt inputs on 136 * the interrupt controller. 137 */ 138 else 139 entry->link.index = prt->source_index; 140 141 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO, 142 " %02X:%02X:%02X[%c] -> %s[%d]\n", 143 entry->id.segment, entry->id.bus, entry->id.device, 144 ('A' + entry->pin), prt->source, entry->link.index)); 145 146 spin_lock(&acpi_prt_lock); 147 list_add_tail(&entry->node, &acpi_prt.entries); 148 acpi_prt.count++; 149 spin_unlock(&acpi_prt_lock); 150 151 return_VALUE(0); 152 } 153 154 155 static void 156 acpi_pci_irq_del_entry ( 157 int segment, 158 int bus, 159 struct acpi_prt_entry *entry) 160 { 161 if (segment == entry->id.segment && bus == entry->id.bus){ 162 acpi_prt.count--; 163 list_del(&entry->node); 164 kfree(entry); 165 } 166 } 167 168 169 int 170 acpi_pci_irq_add_prt ( 171 acpi_handle handle, 172 int segment, 173 int bus) 174 { 175 acpi_status status = AE_OK; 176 char *pathname = NULL; 177 struct acpi_buffer buffer = {0, NULL}; 178 struct acpi_pci_routing_table *prt = NULL; 179 struct acpi_pci_routing_table *entry = NULL; 180 static int first_time = 1; 181 182 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt"); 183 184 pathname = (char *) kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL); 185 if(!pathname) 186 return_VALUE(-ENOMEM); 187 memset(pathname, 0, ACPI_PATHNAME_MAX); 188 189 if (first_time) { 190 acpi_prt.count = 0; 191 INIT_LIST_HEAD(&acpi_prt.entries); 192 first_time = 0; 193 } 194 195 /* 196 * NOTE: We're given a 'handle' to the _PRT object's parent device 197 * (either a PCI root bridge or PCI-PCI bridge). 198 */ 199 200 buffer.length = ACPI_PATHNAME_MAX; 201 buffer.pointer = pathname; 202 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 203 204 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n", 205 pathname); 206 207 /* 208 * Evaluate this _PRT and add its entries to our global list (acpi_prt). 209 */ 210 211 buffer.length = 0; 212 buffer.pointer = NULL; 213 kfree(pathname); 214 status = acpi_get_irq_routing_table(handle, &buffer); 215 if (status != AE_BUFFER_OVERFLOW) { 216 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n", 217 acpi_format_exception(status))); 218 return_VALUE(-ENODEV); 219 } 220 221 prt = kmalloc(buffer.length, GFP_KERNEL); 222 if (!prt){ 223 return_VALUE(-ENOMEM); 224 } 225 memset(prt, 0, buffer.length); 226 buffer.pointer = prt; 227 228 status = acpi_get_irq_routing_table(handle, &buffer); 229 if (ACPI_FAILURE(status)) { 230 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n", 231 acpi_format_exception(status))); 232 kfree(buffer.pointer); 233 return_VALUE(-ENODEV); 234 } 235 236 entry = prt; 237 238 while (entry && (entry->length > 0)) { 239 acpi_pci_irq_add_entry(handle, segment, bus, entry); 240 entry = (struct acpi_pci_routing_table *) 241 ((unsigned long) entry + entry->length); 242 } 243 244 kfree(prt); 245 246 return_VALUE(0); 247 } 248 249 void 250 acpi_pci_irq_del_prt (int segment, int bus) 251 { 252 struct list_head *node = NULL, *n = NULL; 253 struct acpi_prt_entry *entry = NULL; 254 255 if (!acpi_prt.count) { 256 return; 257 } 258 259 printk(KERN_DEBUG "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", 260 segment, bus); 261 spin_lock(&acpi_prt_lock); 262 list_for_each_safe(node, n, &acpi_prt.entries) { 263 entry = list_entry(node, struct acpi_prt_entry, node); 264 265 acpi_pci_irq_del_entry(segment, bus, entry); 266 } 267 spin_unlock(&acpi_prt_lock); 268 } 269 /* -------------------------------------------------------------------------- 270 PCI Interrupt Routing Support 271 -------------------------------------------------------------------------- */ 272 273 /* 274 * acpi_pci_irq_lookup 275 * success: return IRQ >= 0 276 * failure: return -1 277 */ 278 static int 279 acpi_pci_irq_lookup ( 280 struct pci_bus *bus, 281 int device, 282 int pin, 283 int *edge_level, 284 int *active_high_low, 285 char **link) 286 { 287 struct acpi_prt_entry *entry = NULL; 288 int segment = pci_domain_nr(bus); 289 int bus_nr = bus->number; 290 int irq; 291 292 ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup"); 293 294 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 295 "Searching for PRT entry for %02x:%02x:%02x[%c]\n", 296 segment, bus_nr, device, ('A' + pin))); 297 298 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin); 299 if (!entry) { 300 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n")); 301 return_VALUE(-1); 302 } 303 304 if (entry->link.handle) { 305 irq = acpi_pci_link_get_irq(entry->link.handle, 306 entry->link.index, edge_level, active_high_low, link); 307 if (irq < 0) { 308 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n")); 309 return_VALUE(-1); 310 } 311 } else { 312 irq = entry->link.index; 313 *edge_level = ACPI_LEVEL_SENSITIVE; 314 *active_high_low = ACPI_ACTIVE_LOW; 315 } 316 317 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq)); 318 319 return_VALUE(irq); 320 } 321 322 /* 323 * acpi_pci_irq_derive 324 * success: return IRQ >= 0 325 * failure: return < 0 326 */ 327 static int 328 acpi_pci_irq_derive ( 329 struct pci_dev *dev, 330 int pin, 331 int *edge_level, 332 int *active_high_low, 333 char **link) 334 { 335 struct pci_dev *bridge = dev; 336 int irq = -1; 337 u8 bridge_pin = 0; 338 339 ACPI_FUNCTION_TRACE("acpi_pci_irq_derive"); 340 341 if (!dev) 342 return_VALUE(-EINVAL); 343 344 /* 345 * Attempt to derive an IRQ for this device from a parent bridge's 346 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge). 347 */ 348 while (irq < 0 && bridge->bus->self) { 349 pin = (pin + PCI_SLOT(bridge->devfn)) % 4; 350 bridge = bridge->bus->self; 351 352 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) { 353 /* PC card has the same IRQ as its cardbridge */ 354 pci_read_config_byte(bridge, PCI_INTERRUPT_PIN, &bridge_pin); 355 if (!bridge_pin) { 356 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 357 "No interrupt pin configured for device %s\n", pci_name(bridge))); 358 return_VALUE(-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, edge_level, active_high_low, link); 367 } 368 369 if (irq < 0) { 370 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Unable to derive IRQ for device %s\n", pci_name(dev))); 371 return_VALUE(-1); 372 } 373 374 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n", 375 irq, pci_name(dev), pci_name(bridge))); 376 377 return_VALUE(irq); 378 } 379 380 /* 381 * acpi_pci_irq_enable 382 * success: return 0 383 * failure: return < 0 384 */ 385 386 int 387 acpi_pci_irq_enable ( 388 struct pci_dev *dev) 389 { 390 int irq = 0; 391 u8 pin = 0; 392 int edge_level = ACPI_LEVEL_SENSITIVE; 393 int active_high_low = ACPI_ACTIVE_LOW; 394 extern int via_interrupt_line_quirk; 395 char *link = NULL; 396 397 ACPI_FUNCTION_TRACE("acpi_pci_irq_enable"); 398 399 if (!dev) 400 return_VALUE(-EINVAL); 401 402 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); 403 if (!pin) { 404 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", pci_name(dev))); 405 return_VALUE(0); 406 } 407 pin--; 408 409 if (!dev->bus) { 410 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n")); 411 return_VALUE(-ENODEV); 412 } 413 414 /* 415 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT 416 * values override any BIOS-assigned IRQs set during boot. 417 */ 418 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 419 &edge_level, &active_high_low, &link); 420 421 /* 422 * If no PRT entry was found, we'll try to derive an IRQ from the 423 * device's parent bridge. 424 */ 425 if (irq < 0) 426 irq = acpi_pci_irq_derive(dev, pin, &edge_level, 427 &active_high_low, &link); 428 429 /* 430 * No IRQ known to the ACPI subsystem - maybe the BIOS / 431 * driver reported one, then use it. Exit in any case. 432 */ 433 if (irq < 0) { 434 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI", 435 pci_name(dev), ('A' + pin)); 436 /* Interrupt Line values above 0xF are forbidden */ 437 if (dev->irq >= 0 && (dev->irq <= 0xF)) { 438 printk(" - using IRQ %d\n", dev->irq); 439 return_VALUE(0); 440 } 441 else { 442 printk("\n"); 443 return_VALUE(0); 444 } 445 } 446 447 if (via_interrupt_line_quirk) 448 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq & 15); 449 450 dev->irq = acpi_register_gsi(irq, edge_level, active_high_low); 451 452 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ", 453 pci_name(dev), 'A' + pin); 454 455 if (link) 456 printk("Link [%s] -> ", link); 457 458 printk("GSI %u (%s, %s) -> IRQ %d\n", irq, 459 (edge_level == ACPI_LEVEL_SENSITIVE) ? "level" : "edge", 460 (active_high_low == ACPI_ACTIVE_LOW) ? "low" : "high", 461 dev->irq); 462 463 return_VALUE(0); 464 } 465 EXPORT_SYMBOL(acpi_pci_irq_enable); 466 467 468 #ifdef CONFIG_ACPI_DEALLOCATE_IRQ 469 void 470 acpi_pci_irq_disable ( 471 struct pci_dev *dev) 472 { 473 int gsi = 0; 474 u8 pin = 0; 475 int edge_level = ACPI_LEVEL_SENSITIVE; 476 int active_high_low = ACPI_ACTIVE_LOW; 477 478 ACPI_FUNCTION_TRACE("acpi_pci_irq_disable"); 479 480 if (!dev) 481 return_VOID; 482 483 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); 484 if (!pin) 485 return_VOID; 486 pin--; 487 488 if (!dev->bus) 489 return_VOID; 490 491 /* 492 * First we check the PCI IRQ routing table (PRT) for an IRQ. 493 */ 494 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 495 &edge_level, &active_high_low, NULL); 496 /* 497 * If no PRT entry was found, we'll try to derive an IRQ from the 498 * device's parent bridge. 499 */ 500 if (gsi < 0) 501 gsi = acpi_pci_irq_derive(dev, pin, 502 &edge_level, &active_high_low, NULL); 503 if (gsi < 0) 504 return_VOID; 505 506 /* 507 * TBD: It might be worth clearing dev->irq by magic constant 508 * (e.g. PCI_UNDEFINED_IRQ). 509 */ 510 511 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n", 512 pci_name(dev)); 513 514 acpi_unregister_gsi(gsi); 515 516 return_VOID; 517 } 518 #endif /* CONFIG_ACPI_DEALLOCATE_IRQ */ 519