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 = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL); 93 if (!entry) 94 return -ENOMEM; 95 memset(entry, 0, sizeof(struct acpi_prt_entry)); 96 97 entry->id.segment = segment; 98 entry->id.bus = bus; 99 entry->id.device = (prt->address >> 16) & 0xFFFF; 100 entry->id.function = prt->address & 0xFFFF; 101 entry->pin = prt->pin; 102 103 /* 104 * Type 1: Dynamic 105 * --------------- 106 * The 'source' field specifies the PCI interrupt link device used to 107 * configure the IRQ assigned to this slot|dev|pin. The 'source_index' 108 * indicates which resource descriptor in the resource template (of 109 * the link device) this interrupt is allocated from. 110 * 111 * NOTE: Don't query the Link Device for IRQ information at this time 112 * because Link Device enumeration may not have occurred yet 113 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI 114 * namespace). 115 */ 116 if (prt->source[0]) { 117 acpi_get_handle(handle, prt->source, &entry->link.handle); 118 entry->link.index = prt->source_index; 119 } 120 /* 121 * Type 2: Static 122 * -------------- 123 * The 'source' field is NULL, and the 'source_index' field specifies 124 * the IRQ value, which is hardwired to specific interrupt inputs on 125 * the interrupt controller. 126 */ 127 else 128 entry->link.index = prt->source_index; 129 130 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO, 131 " %02X:%02X:%02X[%c] -> %s[%d]\n", 132 entry->id.segment, entry->id.bus, 133 entry->id.device, ('A' + entry->pin), prt->source, 134 entry->link.index)); 135 136 spin_lock(&acpi_prt_lock); 137 list_add_tail(&entry->node, &acpi_prt.entries); 138 acpi_prt.count++; 139 spin_unlock(&acpi_prt_lock); 140 141 return 0; 142 } 143 144 static void 145 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry) 146 { 147 if (segment == entry->id.segment && bus == entry->id.bus) { 148 acpi_prt.count--; 149 list_del(&entry->node); 150 kfree(entry); 151 } 152 } 153 154 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus) 155 { 156 acpi_status status = AE_OK; 157 char *pathname = NULL; 158 struct acpi_buffer buffer = { 0, NULL }; 159 struct acpi_pci_routing_table *prt = NULL; 160 struct acpi_pci_routing_table *entry = NULL; 161 static int first_time = 1; 162 163 164 pathname = (char *)kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL); 165 if (!pathname) 166 return -ENOMEM; 167 memset(pathname, 0, ACPI_PATHNAME_MAX); 168 169 if (first_time) { 170 acpi_prt.count = 0; 171 INIT_LIST_HEAD(&acpi_prt.entries); 172 first_time = 0; 173 } 174 175 /* 176 * NOTE: We're given a 'handle' to the _PRT object's parent device 177 * (either a PCI root bridge or PCI-PCI bridge). 178 */ 179 180 buffer.length = ACPI_PATHNAME_MAX; 181 buffer.pointer = pathname; 182 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 183 184 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n", 185 pathname); 186 187 /* 188 * Evaluate this _PRT and add its entries to our global list (acpi_prt). 189 */ 190 191 buffer.length = 0; 192 buffer.pointer = NULL; 193 kfree(pathname); 194 status = acpi_get_irq_routing_table(handle, &buffer); 195 if (status != AE_BUFFER_OVERFLOW) { 196 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]", 197 acpi_format_exception(status))); 198 return -ENODEV; 199 } 200 201 prt = kmalloc(buffer.length, GFP_KERNEL); 202 if (!prt) { 203 return -ENOMEM; 204 } 205 memset(prt, 0, buffer.length); 206 buffer.pointer = prt; 207 208 status = acpi_get_irq_routing_table(handle, &buffer); 209 if (ACPI_FAILURE(status)) { 210 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]", 211 acpi_format_exception(status))); 212 kfree(buffer.pointer); 213 return -ENODEV; 214 } 215 216 entry = prt; 217 218 while (entry && (entry->length > 0)) { 219 acpi_pci_irq_add_entry(handle, segment, bus, entry); 220 entry = (struct acpi_pci_routing_table *) 221 ((unsigned long)entry + entry->length); 222 } 223 224 kfree(prt); 225 226 return 0; 227 } 228 229 void acpi_pci_irq_del_prt(int segment, int bus) 230 { 231 struct list_head *node = NULL, *n = NULL; 232 struct acpi_prt_entry *entry = NULL; 233 234 if (!acpi_prt.count) { 235 return; 236 } 237 238 printk(KERN_DEBUG 239 "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment, 240 bus); 241 spin_lock(&acpi_prt_lock); 242 list_for_each_safe(node, n, &acpi_prt.entries) { 243 entry = list_entry(node, struct acpi_prt_entry, node); 244 245 acpi_pci_irq_del_entry(segment, bus, entry); 246 } 247 spin_unlock(&acpi_prt_lock); 248 } 249 250 /* -------------------------------------------------------------------------- 251 PCI Interrupt Routing Support 252 -------------------------------------------------------------------------- */ 253 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **); 254 255 static int 256 acpi_pci_allocate_irq(struct acpi_prt_entry *entry, 257 int *triggering, int *polarity, char **link) 258 { 259 int irq; 260 261 262 if (entry->link.handle) { 263 irq = acpi_pci_link_allocate_irq(entry->link.handle, 264 entry->link.index, triggering, 265 polarity, link); 266 if (irq < 0) { 267 printk(KERN_WARNING PREFIX 268 "Invalid IRQ link routing entry\n"); 269 return -1; 270 } 271 } else { 272 irq = entry->link.index; 273 *triggering = ACPI_LEVEL_SENSITIVE; 274 *polarity = ACPI_ACTIVE_LOW; 275 } 276 277 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq)); 278 return irq; 279 } 280 281 static int 282 acpi_pci_free_irq(struct acpi_prt_entry *entry, 283 int *triggering, int *polarity, char **link) 284 { 285 int irq; 286 287 if (entry->link.handle) { 288 irq = acpi_pci_link_free_irq(entry->link.handle); 289 } else { 290 irq = entry->link.index; 291 } 292 return irq; 293 } 294 295 /* 296 * acpi_pci_irq_lookup 297 * success: return IRQ >= 0 298 * failure: return -1 299 */ 300 static int 301 acpi_pci_irq_lookup(struct pci_bus *bus, 302 int device, 303 int pin, 304 int *triggering, 305 int *polarity, char **link, irq_lookup_func func) 306 { 307 struct acpi_prt_entry *entry = NULL; 308 int segment = pci_domain_nr(bus); 309 int bus_nr = bus->number; 310 int ret; 311 312 313 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 314 "Searching for PRT entry for %02x:%02x:%02x[%c]\n", 315 segment, bus_nr, device, ('A' + pin))); 316 317 entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin); 318 if (!entry) { 319 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n")); 320 return -1; 321 } 322 323 ret = func(entry, triggering, polarity, link); 324 return ret; 325 } 326 327 /* 328 * acpi_pci_irq_derive 329 * success: return IRQ >= 0 330 * failure: return < 0 331 */ 332 static int 333 acpi_pci_irq_derive(struct pci_dev *dev, 334 int pin, 335 int *triggering, 336 int *polarity, char **link, irq_lookup_func func) 337 { 338 struct pci_dev *bridge = dev; 339 int irq = -1; 340 u8 bridge_pin = 0; 341 342 343 if (!dev) 344 return -EINVAL; 345 346 /* 347 * Attempt to derive an IRQ for this device from a parent bridge's 348 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge). 349 */ 350 while (irq < 0 && bridge->bus->self) { 351 pin = (pin + PCI_SLOT(bridge->devfn)) % 4; 352 bridge = bridge->bus->self; 353 354 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) { 355 /* PC card has the same IRQ as its cardbridge */ 356 bridge_pin = bridge->pin; 357 if (!bridge_pin) { 358 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 359 "No interrupt pin configured for device %s\n", 360 pci_name(bridge))); 361 return -1; 362 } 363 /* Pin is from 0 to 3 */ 364 bridge_pin--; 365 pin = bridge_pin; 366 } 367 368 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn), 369 pin, triggering, polarity, 370 link, func); 371 } 372 373 if (irq < 0) { 374 printk(KERN_WARNING PREFIX "Unable to derive IRQ for device %s\n", 375 pci_name(dev)); 376 return -1; 377 } 378 379 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n", 380 irq, pci_name(dev), pci_name(bridge))); 381 382 return irq; 383 } 384 385 /* 386 * acpi_pci_irq_enable 387 * success: return 0 388 * failure: return < 0 389 */ 390 391 int acpi_pci_irq_enable(struct pci_dev *dev) 392 { 393 int irq = 0; 394 u8 pin = 0; 395 int triggering = ACPI_LEVEL_SENSITIVE; 396 int polarity = ACPI_ACTIVE_LOW; 397 char *link = NULL; 398 int rc; 399 400 401 if (!dev) 402 return -EINVAL; 403 404 pin = dev->pin; 405 if (!pin) { 406 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 407 "No interrupt pin configured for device %s\n", 408 pci_name(dev))); 409 return 0; 410 } 411 pin--; 412 413 if (!dev->bus) { 414 printk(KERN_ERR PREFIX "Invalid (NULL) 'bus' field\n"); 415 return -ENODEV; 416 } 417 418 /* 419 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT 420 * values override any BIOS-assigned IRQs set during boot. 421 */ 422 irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 423 &triggering, &polarity, &link, 424 acpi_pci_allocate_irq); 425 426 /* 427 * If no PRT entry was found, we'll try to derive an IRQ from the 428 * device's parent bridge. 429 */ 430 if (irq < 0) 431 irq = acpi_pci_irq_derive(dev, pin, &triggering, 432 &polarity, &link, 433 acpi_pci_allocate_irq); 434 435 /* 436 * No IRQ known to the ACPI subsystem - maybe the BIOS / 437 * driver reported one, then use it. Exit in any case. 438 */ 439 if (irq < 0) { 440 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI", 441 pci_name(dev), ('A' + pin)); 442 /* Interrupt Line values above 0xF are forbidden */ 443 if (dev->irq > 0 && (dev->irq <= 0xF)) { 444 printk(" - using IRQ %d\n", dev->irq); 445 acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE, 446 ACPI_ACTIVE_LOW); 447 return 0; 448 } else { 449 printk("\n"); 450 return 0; 451 } 452 } 453 454 rc = acpi_register_gsi(irq, triggering, polarity); 455 if (rc < 0) { 456 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed " 457 "to register GSI\n", pci_name(dev), ('A' + pin)); 458 return rc; 459 } 460 dev->irq = rc; 461 462 printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ", 463 pci_name(dev), 'A' + pin); 464 465 if (link) 466 printk("Link [%s] -> ", link); 467 468 printk("GSI %u (%s, %s) -> IRQ %d\n", irq, 469 (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge", 470 (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq); 471 472 return 0; 473 } 474 475 EXPORT_SYMBOL(acpi_pci_irq_enable); 476 477 /* FIXME: implement x86/x86_64 version */ 478 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i) 479 { 480 } 481 482 void acpi_pci_irq_disable(struct pci_dev *dev) 483 { 484 int gsi = 0; 485 u8 pin = 0; 486 int triggering = ACPI_LEVEL_SENSITIVE; 487 int polarity = ACPI_ACTIVE_LOW; 488 489 490 if (!dev || !dev->bus) 491 return; 492 493 pin = dev->pin; 494 if (!pin) 495 return; 496 pin--; 497 498 /* 499 * First we check the PCI IRQ routing table (PRT) for an IRQ. 500 */ 501 gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin, 502 &triggering, &polarity, NULL, 503 acpi_pci_free_irq); 504 /* 505 * If no PRT entry was found, we'll try to derive an IRQ from the 506 * device's parent bridge. 507 */ 508 if (gsi < 0) 509 gsi = acpi_pci_irq_derive(dev, pin, 510 &triggering, &polarity, NULL, 511 acpi_pci_free_irq); 512 if (gsi < 0) 513 return; 514 515 /* 516 * TBD: It might be worth clearing dev->irq by magic constant 517 * (e.g. PCI_UNDEFINED_IRQ). 518 */ 519 520 printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n", 521 pci_name(dev)); 522 523 acpi_unregister_gsi(gsi); 524 525 return; 526 } 527