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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 typedef int (*irq_lookup_func)(struct acpi_prt_entry *, int *, int *, char **);
 273
 274 static int
 275 acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
 276         int     *edge_level,
 277         int     *active_high_low,
 278         char    **link)
 279 {
 280         int     irq;
 281
 282         ACPI_FUNCTION_TRACE("acpi_pci_allocate_irq");
 283
 284         if (entry->link.handle) {
 285                 irq = acpi_pci_link_allocate_irq(entry->link.handle,
 286                         entry->link.index, edge_level, active_high_low, link);
 287                 if (irq < 0) {
 288                         ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n"));
 289                         return_VALUE(-1);
 290                 }
 291         } else {
 292                 irq = entry->link.index;
 293                 *edge_level = ACPI_LEVEL_SENSITIVE;
 294                 *active_high_low = ACPI_ACTIVE_LOW;
 295         }
 296
 297         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
 298         return_VALUE(irq);
 299 }
 300
 301 static int
 302 acpi_pci_free_irq(struct acpi_prt_entry *entry,
 303         int     *edge_level,
 304         int     *active_high_low,
 305         char    **link)
 306 {
 307         int     irq;
 308
 309         ACPI_FUNCTION_TRACE("acpi_pci_free_irq");
 310         if (entry->link.handle) {
 311                 irq = acpi_pci_link_free_irq(entry->link.handle);
 312         } else {
 313                 irq = entry->link.index;
 314         }
 315         return_VALUE(irq);
 316 }
 317 /*
 318  * acpi_pci_irq_lookup
 319  * success: return IRQ >= 0
 320  * failure: return -1
 321  */
 322 static int
 323 acpi_pci_irq_lookup (
 324         struct pci_bus          *bus,
 325         int                     device,
 326         int                     pin,
 327         int                     *edge_level,
 328         int                     *active_high_low,
 329         char                    **link,
 330         irq_lookup_func         func)
 331 {
 332         struct acpi_prt_entry   *entry = NULL;
 333         int segment = pci_domain_nr(bus);
 334         int bus_nr = bus->number;
 335         int ret;
 336
 337         ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");
 338
 339         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 340                 "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
 341                 segment, bus_nr, device, ('A' + pin)));
 342
 343         entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
 344         if (!entry) {
 345                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
 346                 return_VALUE(-1);
 347         }
 348
 349         ret = func(entry, edge_level, active_high_low, link);
 350         return_VALUE(ret);
 351 }
 352
 353 /*
 354  * acpi_pci_irq_derive
 355  * success: return IRQ >= 0
 356  * failure: return < 0
 357  */
 358 static int
 359 acpi_pci_irq_derive (
 360         struct pci_dev          *dev,
 361         int                     pin,
 362         int                     *edge_level,
 363         int                     *active_high_low,
 364         char                    **link,
 365         irq_lookup_func         func)
 366 {
 367         struct pci_dev          *bridge = dev;
 368         int                     irq = -1;
 369         u8                      bridge_pin = 0;
 370
 371         ACPI_FUNCTION_TRACE("acpi_pci_irq_derive");
 372
 373         if (!dev)
 374                 return_VALUE(-EINVAL);
 375
 376         /*
 377          * Attempt to derive an IRQ for this device from a parent bridge's
 378          * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
 379          */
 380         while (irq < 0 && bridge->bus->self) {
 381                 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
 382                 bridge = bridge->bus->self;
 383
 384                 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
 385                         /* PC card has the same IRQ as its cardbridge */
 386                         pci_read_config_byte(bridge, PCI_INTERRUPT_PIN, &bridge_pin);
 387                         if (!bridge_pin) {
 388                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 389                                         "No interrupt pin configured for device %s\n", pci_name(bridge)));
 390                                 return_VALUE(-1);
 391                         }
 392                         /* Pin is from 0 to 3 */
 393                         bridge_pin --;
 394                         pin = bridge_pin;
 395                 }
 396
 397                 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
 398                         pin, edge_level, active_high_low, link, func);
 399         }
 400
 401         if (irq < 0) {
 402                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Unable to derive IRQ for device %s\n", pci_name(dev)));
 403                 return_VALUE(-1);
 404         }
 405
 406         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
 407                 irq, pci_name(dev), pci_name(bridge)));
 408
 409         return_VALUE(irq);
 410 }
 411
 412 /*
 413  * acpi_pci_irq_enable
 414  * success: return 0
 415  * failure: return < 0
 416  */
 417
 418 int
 419 acpi_pci_irq_enable (
 420         struct pci_dev          *dev)
 421 {
 422         int                     irq = 0;
 423         u8                      pin = 0;
 424         int                     edge_level = ACPI_LEVEL_SENSITIVE;
 425         int                     active_high_low = ACPI_ACTIVE_LOW;
 426         char                    *link = NULL;
 427         int                     rc;
 428
 429         ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
 430
 431         if (!dev)
 432                 return_VALUE(-EINVAL);
 433
 434         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 435         if (!pin) {
 436                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", pci_name(dev)));
 437                 return_VALUE(0);
 438         }
 439         pin--;
 440
 441         if (!dev->bus) {
 442                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n"));
 443                 return_VALUE(-ENODEV);
 444         }
 445
 446         /*
 447          * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
 448          * values override any BIOS-assigned IRQs set during boot.
 449          */
 450         irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 451                 &edge_level, &active_high_low, &link, acpi_pci_allocate_irq);
 452
 453         /*
 454          * If no PRT entry was found, we'll try to derive an IRQ from the
 455          * device's parent bridge.
 456          */
 457         if (irq < 0)
 458                 irq = acpi_pci_irq_derive(dev, pin, &edge_level,
 459                         &active_high_low, &link, acpi_pci_allocate_irq);
 460
 461         /*
 462          * No IRQ known to the ACPI subsystem - maybe the BIOS /
 463          * driver reported one, then use it. Exit in any case.
 464          */
 465         if (irq < 0) {
 466                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
 467                         pci_name(dev), ('A' + pin));
 468                 /* Interrupt Line values above 0xF are forbidden */
 469                 if (dev->irq > 0 && (dev->irq <= 0xF)) {
 470                         printk(" - using IRQ %d\n", dev->irq);
 471                         acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_LOW);
 472                         return_VALUE(0);
 473                 }
 474                 else {
 475                         printk("\n");
 476                         return_VALUE(0);
 477                 }
 478         }
 479
 480         rc = acpi_register_gsi(irq, edge_level, active_high_low);
 481         if (rc < 0) {
 482                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
 483                        "to register GSI\n", pci_name(dev), ('A' + pin));
 484                 return_VALUE(rc);
 485         }
 486         dev->irq = rc;
 487
 488         printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
 489                 pci_name(dev), 'A' + pin);
 490
 491         if (link)
 492                 printk("Link [%s] -> ", link);
 493
 494         printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
 495                 (edge_level == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
 496                 (active_high_low == ACPI_ACTIVE_LOW) ? "low" : "high",
 497                 dev->irq);
 498
 499         return_VALUE(0);
 500 }
 501 EXPORT_SYMBOL(acpi_pci_irq_enable);
 502
 503
 504 /* FIXME: implement x86/x86_64 version */
 505 void __attribute__((weak)) acpi_unregister_gsi(u32 i) {}
 506
 507 void
 508 acpi_pci_irq_disable (
 509         struct pci_dev          *dev)
 510 {
 511         int                     gsi = 0;
 512         u8                      pin = 0;
 513         int                     edge_level = ACPI_LEVEL_SENSITIVE;
 514         int                     active_high_low = ACPI_ACTIVE_LOW;
 515
 516         ACPI_FUNCTION_TRACE("acpi_pci_irq_disable");
 517
 518         if (!dev)
 519                 return_VOID;
 520
 521         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 522         if (!pin)
 523                 return_VOID;
 524         pin--;
 525
 526         if (!dev->bus)
 527                 return_VOID;
 528
 529         /*
 530          * First we check the PCI IRQ routing table (PRT) for an IRQ.
 531          */
 532         gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 533                         &edge_level, &active_high_low, NULL, acpi_pci_free_irq);
 534         /*
 535          * If no PRT entry was found, we'll try to derive an IRQ from the
 536          * device's parent bridge.
 537          */
 538         if (gsi < 0)
 539                 gsi = acpi_pci_irq_derive(dev, pin,
 540                         &edge_level, &active_high_low, NULL, acpi_pci_free_irq);
 541         if (gsi < 0)
 542                 return_VOID;
 543
 544         /*
 545          * TBD: It might be worth clearing dev->irq by magic constant
 546          * (e.g. PCI_UNDEFINED_IRQ).
 547          */
 548
 549         printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
 550                pci_name(dev));
 551
 552         acpi_unregister_gsi(gsi);
 553
 554         return_VOID;
 555 }