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   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         char                    *link = NULL;
 395
 396         ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
 397
 398         if (!dev)
 399                 return_VALUE(-EINVAL);
 400
 401         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 402         if (!pin) {
 403                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", pci_name(dev)));
 404                 return_VALUE(0);
 405         }
 406         pin--;
 407
 408         if (!dev->bus) {
 409                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n"));
 410                 return_VALUE(-ENODEV);
 411         }
 412
 413         /*
 414          * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
 415          * values override any BIOS-assigned IRQs set during boot.
 416          */
 417         irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 418                 &edge_level, &active_high_low, &link);
 419
 420         /*
 421          * If no PRT entry was found, we'll try to derive an IRQ from the
 422          * device's parent bridge.
 423          */
 424         if (irq < 0)
 425                 irq = acpi_pci_irq_derive(dev, pin, &edge_level,
 426                         &active_high_low, &link);
 427
 428         /*
 429          * No IRQ known to the ACPI subsystem - maybe the BIOS /
 430          * driver reported one, then use it. Exit in any case.
 431          */
 432         if (irq < 0) {
 433                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
 434                         pci_name(dev), ('A' + pin));
 435                 /* Interrupt Line values above 0xF are forbidden */
 436                 if (dev->irq >= 0 && (dev->irq <= 0xF)) {
 437                         printk(" - using IRQ %d\n", dev->irq);
 438                         return_VALUE(0);
 439                 }
 440                 else {
 441                         printk("\n");
 442                         return_VALUE(0);
 443                 }
 444         }
 445
 446         dev->irq = acpi_register_gsi(irq, edge_level, active_high_low);
 447
 448         printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
 449                 pci_name(dev), 'A' + pin);
 450
 451         if (link)
 452                 printk("Link [%s] -> ", link);
 453
 454         printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
 455                 (edge_level == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
 456                 (active_high_low == ACPI_ACTIVE_LOW) ? "low" : "high",
 457                 dev->irq);
 458
 459         return_VALUE(0);
 460 }
 461 EXPORT_SYMBOL(acpi_pci_irq_enable);
 462
 463
 464 #ifdef CONFIG_ACPI_DEALLOCATE_IRQ
 465 void
 466 acpi_pci_irq_disable (
 467         struct pci_dev          *dev)
 468 {
 469         int                     gsi = 0;
 470         u8                      pin = 0;
 471         int                     edge_level = ACPI_LEVEL_SENSITIVE;
 472         int                     active_high_low = ACPI_ACTIVE_LOW;
 473
 474         ACPI_FUNCTION_TRACE("acpi_pci_irq_disable");
 475
 476         if (!dev)
 477                 return_VOID;
 478
 479         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 480         if (!pin)
 481                 return_VOID;
 482         pin--;
 483
 484         if (!dev->bus)
 485                 return_VOID;
 486
 487         /*
 488          * First we check the PCI IRQ routing table (PRT) for an IRQ.
 489          */
 490         gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 491                                   &edge_level, &active_high_low, NULL);
 492         /*
 493          * If no PRT entry was found, we'll try to derive an IRQ from the
 494          * device's parent bridge.
 495          */
 496         if (gsi < 0)
 497                 gsi = acpi_pci_irq_derive(dev, pin,
 498                                           &edge_level, &active_high_low, NULL);
 499         if (gsi < 0)
 500                 return_VOID;
 501
 502         /*
 503          * TBD: It might be worth clearing dev->irq by magic constant
 504          * (e.g. PCI_UNDEFINED_IRQ).
 505          */
 506
 507         printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
 508                pci_name(dev));
 509
 510         acpi_unregister_gsi(gsi);
 511
 512         return_VOID;
 513 }
 514 #endif /* CONFIG_ACPI_DEALLOCATE_IRQ */