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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 #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                         pci_read_config_byte(bridge, PCI_INTERRUPT_PIN,
 365                                              &bridge_pin);
 366                         if (!bridge_pin) {
 367                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 368                                                   "No interrupt pin configured for device %s\n",
 369                                                   pci_name(bridge)));
 370                                 return_VALUE(-1);
 371                         }
 372                         /* Pin is from 0 to 3 */
 373                         bridge_pin--;
 374                         pin = bridge_pin;
 375                 }
 376
 377                 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
 378                                           pin, edge_level, active_high_low,
 379                                           link, func);
 380         }
 381
 382         if (irq < 0) {
 383                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 384                                   "Unable to derive IRQ for device %s\n",
 385                                   pci_name(dev)));
 386                 return_VALUE(-1);
 387         }
 388
 389         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
 390                           irq, pci_name(dev), pci_name(bridge)));
 391
 392         return_VALUE(irq);
 393 }
 394
 395 /*
 396  * acpi_pci_irq_enable
 397  * success: return 0
 398  * failure: return < 0
 399  */
 400
 401 int acpi_pci_irq_enable(struct pci_dev *dev)
 402 {
 403         int irq = 0;
 404         u8 pin = 0;
 405         int edge_level = ACPI_LEVEL_SENSITIVE;
 406         int active_high_low = ACPI_ACTIVE_LOW;
 407         char *link = NULL;
 408         int rc;
 409
 410         ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
 411
 412         if (!dev)
 413                 return_VALUE(-EINVAL);
 414
 415         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 416         if (!pin) {
 417                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 418                                   "No interrupt pin configured for device %s\n",
 419                                   pci_name(dev)));
 420                 return_VALUE(0);
 421         }
 422         pin--;
 423
 424         if (!dev->bus) {
 425                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 426                                   "Invalid (NULL) 'bus' field\n"));
 427                 return_VALUE(-ENODEV);
 428         }
 429
 430         /*
 431          * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
 432          * values override any BIOS-assigned IRQs set during boot.
 433          */
 434         irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 435                                   &edge_level, &active_high_low, &link,
 436                                   acpi_pci_allocate_irq);
 437
 438         /*
 439          * If no PRT entry was found, we'll try to derive an IRQ from the
 440          * device's parent bridge.
 441          */
 442         if (irq < 0)
 443                 irq = acpi_pci_irq_derive(dev, pin, &edge_level,
 444                                           &active_high_low, &link,
 445                                           acpi_pci_allocate_irq);
 446
 447         /*
 448          * No IRQ known to the ACPI subsystem - maybe the BIOS /
 449          * driver reported one, then use it. Exit in any case.
 450          */
 451         if (irq < 0) {
 452                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
 453                        pci_name(dev), ('A' + pin));
 454                 /* Interrupt Line values above 0xF are forbidden */
 455                 if (dev->irq > 0 && (dev->irq <= 0xF)) {
 456                         printk(" - using IRQ %d\n", dev->irq);
 457                         acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
 458                                           ACPI_ACTIVE_LOW);
 459                         return_VALUE(0);
 460                 } else {
 461                         printk("\n");
 462                         return_VALUE(0);
 463                 }
 464         }
 465
 466         rc = acpi_register_gsi(irq, edge_level, active_high_low);
 467         if (rc < 0) {
 468                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
 469                        "to register GSI\n", pci_name(dev), ('A' + pin));
 470                 return_VALUE(rc);
 471         }
 472         dev->irq = rc;
 473
 474         printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
 475                pci_name(dev), 'A' + pin);
 476
 477         if (link)
 478                 printk("Link [%s] -> ", link);
 479
 480         printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
 481                (edge_level == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
 482                (active_high_low == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
 483
 484         return_VALUE(0);
 485 }
 486
 487 EXPORT_SYMBOL(acpi_pci_irq_enable);
 488
 489 /* FIXME: implement x86/x86_64 version */
 490 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
 491 {
 492 }
 493
 494 void acpi_pci_irq_disable(struct pci_dev *dev)
 495 {
 496         int gsi = 0;
 497         u8 pin = 0;
 498         int edge_level = ACPI_LEVEL_SENSITIVE;
 499         int active_high_low = ACPI_ACTIVE_LOW;
 500
 501         ACPI_FUNCTION_TRACE("acpi_pci_irq_disable");
 502
 503         if (!dev || !dev->bus)
 504                 return_VOID;
 505
 506         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 507         if (!pin)
 508                 return_VOID;
 509         pin--;
 510
 511         /*
 512          * First we check the PCI IRQ routing table (PRT) for an IRQ.
 513          */
 514         gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 515                                   &edge_level, &active_high_low, NULL,
 516                                   acpi_pci_free_irq);
 517         /*
 518          * If no PRT entry was found, we'll try to derive an IRQ from the
 519          * device's parent bridge.
 520          */
 521         if (gsi < 0)
 522                 gsi = acpi_pci_irq_derive(dev, pin,
 523                                           &edge_level, &active_high_low, NULL,
 524                                           acpi_pci_free_irq);
 525         if (gsi < 0)
 526                 return_VOID;
 527
 528         /*
 529          * TBD: It might be worth clearing dev->irq by magic constant
 530          * (e.g. PCI_UNDEFINED_IRQ).
 531          */
 532
 533         printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
 534                pci_name(dev));
 535
 536         acpi_unregister_gsi(gsi);
 537
 538         return_VOID;
 539 }