err.no Git - linux-2.6/blob - drivers/acpi/pci_irq.c

   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         ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry");
  58
  59         if (!acpi_prt.count)
  60                 return_PTR(NULL);
  61
  62         /*
  63          * Parse through all PRT entries looking for a match on the specified
  64          * PCI device's segment, bus, device, and pin (don't care about func).
  65          *
  66          */
  67         spin_lock(&acpi_prt_lock);
  68         list_for_each(node, &acpi_prt.entries) {
  69                 entry = list_entry(node, struct acpi_prt_entry, node);
  70                 if ((segment == entry->id.segment)
  71                     && (bus == entry->id.bus)
  72                     && (device == entry->id.device)
  73                     && (pin == entry->pin)) {
  74                         spin_unlock(&acpi_prt_lock);
  75                         return_PTR(entry);
  76                 }
  77         }
  78
  79         spin_unlock(&acpi_prt_lock);
  80         return_PTR(NULL);
  81 }
  82
  83 static int
  84 acpi_pci_irq_add_entry(acpi_handle handle,
  85                        int segment, int bus, struct acpi_pci_routing_table *prt)
  86 {
  87         struct acpi_prt_entry *entry = NULL;
  88
  89         ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry");
  90
  91         if (!prt)
  92                 return_VALUE(-EINVAL);
  93
  94         entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
  95         if (!entry)
  96                 return_VALUE(-ENOMEM);
  97         memset(entry, 0, sizeof(struct acpi_prt_entry));
  98
  99         entry->id.segment = segment;
 100         entry->id.bus = bus;
 101         entry->id.device = (prt->address >> 16) & 0xFFFF;
 102         entry->id.function = prt->address & 0xFFFF;
 103         entry->pin = prt->pin;
 104
 105         /*
 106          * Type 1: Dynamic
 107          * ---------------
 108          * The 'source' field specifies the PCI interrupt link device used to
 109          * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
 110          * indicates which resource descriptor in the resource template (of
 111          * the link device) this interrupt is allocated from.
 112          *
 113          * NOTE: Don't query the Link Device for IRQ information at this time
 114          *       because Link Device enumeration may not have occurred yet
 115          *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
 116          *       namespace).
 117          */
 118         if (prt->source[0]) {
 119                 acpi_get_handle(handle, prt->source, &entry->link.handle);
 120                 entry->link.index = prt->source_index;
 121         }
 122         /*
 123          * Type 2: Static
 124          * --------------
 125          * The 'source' field is NULL, and the 'source_index' field specifies
 126          * the IRQ value, which is hardwired to specific interrupt inputs on
 127          * the interrupt controller.
 128          */
 129         else
 130                 entry->link.index = prt->source_index;
 131
 132         ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
 133                               "      %02X:%02X:%02X[%c] -> %s[%d]\n",
 134                               entry->id.segment, entry->id.bus,
 135                               entry->id.device, ('A' + entry->pin), prt->source,
 136                               entry->link.index));
 137
 138         spin_lock(&acpi_prt_lock);
 139         list_add_tail(&entry->node, &acpi_prt.entries);
 140         acpi_prt.count++;
 141         spin_unlock(&acpi_prt_lock);
 142
 143         return_VALUE(0);
 144 }
 145
 146 static void
 147 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry)
 148 {
 149         if (segment == entry->id.segment && bus == entry->id.bus) {
 150                 acpi_prt.count--;
 151                 list_del(&entry->node);
 152                 kfree(entry);
 153         }
 154 }
 155
 156 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
 157 {
 158         acpi_status status = AE_OK;
 159         char *pathname = NULL;
 160         struct acpi_buffer buffer = { 0, NULL };
 161         struct acpi_pci_routing_table *prt = NULL;
 162         struct acpi_pci_routing_table *entry = NULL;
 163         static int first_time = 1;
 164
 165         ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt");
 166
 167         pathname = (char *)kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
 168         if (!pathname)
 169                 return_VALUE(-ENOMEM);
 170         memset(pathname, 0, ACPI_PATHNAME_MAX);
 171
 172         if (first_time) {
 173                 acpi_prt.count = 0;
 174                 INIT_LIST_HEAD(&acpi_prt.entries);
 175                 first_time = 0;
 176         }
 177
 178         /*
 179          * NOTE: We're given a 'handle' to the _PRT object's parent device
 180          *       (either a PCI root bridge or PCI-PCI bridge).
 181          */
 182
 183         buffer.length = ACPI_PATHNAME_MAX;
 184         buffer.pointer = pathname;
 185         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 186
 187         printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
 188                pathname);
 189
 190         /*
 191          * Evaluate this _PRT and add its entries to our global list (acpi_prt).
 192          */
 193
 194         buffer.length = 0;
 195         buffer.pointer = NULL;
 196         kfree(pathname);
 197         status = acpi_get_irq_routing_table(handle, &buffer);
 198         if (status != AE_BUFFER_OVERFLOW) {
 199                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
 200                                   acpi_format_exception(status)));
 201                 return_VALUE(-ENODEV);
 202         }
 203
 204         prt = kmalloc(buffer.length, GFP_KERNEL);
 205         if (!prt) {
 206                 return_VALUE(-ENOMEM);
 207         }
 208         memset(prt, 0, buffer.length);
 209         buffer.pointer = prt;
 210
 211         status = acpi_get_irq_routing_table(handle, &buffer);
 212         if (ACPI_FAILURE(status)) {
 213                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
 214                                   acpi_format_exception(status)));
 215                 kfree(buffer.pointer);
 216                 return_VALUE(-ENODEV);
 217         }
 218
 219         entry = prt;
 220
 221         while (entry && (entry->length > 0)) {
 222                 acpi_pci_irq_add_entry(handle, segment, bus, entry);
 223                 entry = (struct acpi_pci_routing_table *)
 224                     ((unsigned long)entry + entry->length);
 225         }
 226
 227         kfree(prt);
 228
 229         return_VALUE(0);
 230 }
 231
 232 void acpi_pci_irq_del_prt(int segment, int bus)
 233 {
 234         struct list_head *node = NULL, *n = NULL;
 235         struct acpi_prt_entry *entry = NULL;
 236
 237         if (!acpi_prt.count) {
 238                 return;
 239         }
 240
 241         printk(KERN_DEBUG
 242                "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment,
 243                bus);
 244         spin_lock(&acpi_prt_lock);
 245         list_for_each_safe(node, n, &acpi_prt.entries) {
 246                 entry = list_entry(node, struct acpi_prt_entry, node);
 247
 248                 acpi_pci_irq_del_entry(segment, bus, entry);
 249         }
 250         spin_unlock(&acpi_prt_lock);
 251 }
 252
 253 /* --------------------------------------------------------------------------
 254                           PCI Interrupt Routing Support
 255    -------------------------------------------------------------------------- */
 256 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **);
 257
 258 static int
 259 acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
 260                       int *triggering, int *polarity, char **link)
 261 {
 262         int irq;
 263
 264         ACPI_FUNCTION_TRACE("acpi_pci_allocate_irq");
 265
 266         if (entry->link.handle) {
 267                 irq = acpi_pci_link_allocate_irq(entry->link.handle,
 268                                                  entry->link.index, triggering,
 269                                                  polarity, link);
 270                 if (irq < 0) {
 271                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 272                                           "Invalid IRQ link routing entry\n"));
 273                         return_VALUE(-1);
 274                 }
 275         } else {
 276                 irq = entry->link.index;
 277                 *triggering = ACPI_LEVEL_SENSITIVE;
 278                 *polarity = ACPI_ACTIVE_LOW;
 279         }
 280
 281         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
 282         return_VALUE(irq);
 283 }
 284
 285 static int
 286 acpi_pci_free_irq(struct acpi_prt_entry *entry,
 287                   int *triggering, int *polarity, char **link)
 288 {
 289         int irq;
 290
 291         ACPI_FUNCTION_TRACE("acpi_pci_free_irq");
 292         if (entry->link.handle) {
 293                 irq = acpi_pci_link_free_irq(entry->link.handle);
 294         } else {
 295                 irq = entry->link.index;
 296         }
 297         return_VALUE(irq);
 298 }
 299
 300 /*
 301  * acpi_pci_irq_lookup
 302  * success: return IRQ >= 0
 303  * failure: return -1
 304  */
 305 static int
 306 acpi_pci_irq_lookup(struct pci_bus *bus,
 307                     int device,
 308                     int pin,
 309                     int *triggering,
 310                     int *polarity, char **link, irq_lookup_func func)
 311 {
 312         struct acpi_prt_entry *entry = NULL;
 313         int segment = pci_domain_nr(bus);
 314         int bus_nr = bus->number;
 315         int ret;
 316
 317         ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");
 318
 319         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 320                           "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
 321                           segment, bus_nr, device, ('A' + pin)));
 322
 323         entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
 324         if (!entry) {
 325                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
 326                 return_VALUE(-1);
 327         }
 328
 329         ret = func(entry, triggering, polarity, link);
 330         return_VALUE(ret);
 331 }
 332
 333 /*
 334  * acpi_pci_irq_derive
 335  * success: return IRQ >= 0
 336  * failure: return < 0
 337  */
 338 static int
 339 acpi_pci_irq_derive(struct pci_dev *dev,
 340                     int pin,
 341                     int *triggering,
 342                     int *polarity, char **link, irq_lookup_func func)
 343 {
 344         struct pci_dev *bridge = dev;
 345         int irq = -1;
 346         u8 bridge_pin = 0;
 347
 348         ACPI_FUNCTION_TRACE("acpi_pci_irq_derive");
 349
 350         if (!dev)
 351                 return_VALUE(-EINVAL);
 352
 353         /*
 354          * Attempt to derive an IRQ for this device from a parent bridge's
 355          * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
 356          */
 357         while (irq < 0 && bridge->bus->self) {
 358                 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
 359                 bridge = bridge->bus->self;
 360
 361                 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
 362                         /* PC card has the same IRQ as its cardbridge */
 363                         bridge_pin = bridge->pin;
 364                         if (!bridge_pin) {
 365                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 366                                                   "No interrupt pin configured for device %s\n",
 367                                                   pci_name(bridge)));
 368                                 return_VALUE(-1);
 369                         }
 370                         /* Pin is from 0 to 3 */
 371                         bridge_pin--;
 372                         pin = bridge_pin;
 373                 }
 374
 375                 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
 376                                           pin, triggering, polarity,
 377                                           link, func);
 378         }
 379
 380         if (irq < 0) {
 381                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 382                                   "Unable to derive IRQ for device %s\n",
 383                                   pci_name(dev)));
 384                 return_VALUE(-1);
 385         }
 386
 387         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
 388                           irq, pci_name(dev), pci_name(bridge)));
 389
 390         return_VALUE(irq);
 391 }
 392
 393 /*
 394  * acpi_pci_irq_enable
 395  * success: return 0
 396  * failure: return < 0
 397  */
 398
 399 int acpi_pci_irq_enable(struct pci_dev *dev)
 400 {
 401         int irq = 0;
 402         u8 pin = 0;
 403         int triggering = ACPI_LEVEL_SENSITIVE;
 404         int polarity = ACPI_ACTIVE_LOW;
 405         char *link = NULL;
 406         int rc;
 407
 408         ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
 409
 410         if (!dev)
 411                 return_VALUE(-EINVAL);
 412
 413         pin = dev->pin;
 414         if (!pin) {
 415                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 416                                   "No interrupt pin configured for device %s\n",
 417                                   pci_name(dev)));
 418                 return_VALUE(0);
 419         }
 420         pin--;
 421
 422         if (!dev->bus) {
 423                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 424                                   "Invalid (NULL) 'bus' field\n"));
 425                 return_VALUE(-ENODEV);
 426         }
 427
 428         /*
 429          * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
 430          * values override any BIOS-assigned IRQs set during boot.
 431          */
 432         irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 433                                   &triggering, &polarity, &link,
 434                                   acpi_pci_allocate_irq);
 435
 436         /*
 437          * If no PRT entry was found, we'll try to derive an IRQ from the
 438          * device's parent bridge.
 439          */
 440         if (irq < 0)
 441                 irq = acpi_pci_irq_derive(dev, pin, &triggering,
 442                                           &polarity, &link,
 443                                           acpi_pci_allocate_irq);
 444
 445         /*
 446          * No IRQ known to the ACPI subsystem - maybe the BIOS /
 447          * driver reported one, then use it. Exit in any case.
 448          */
 449         if (irq < 0) {
 450                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
 451                        pci_name(dev), ('A' + pin));
 452                 /* Interrupt Line values above 0xF are forbidden */
 453                 if (dev->irq > 0 && (dev->irq <= 0xF)) {
 454                         printk(" - using IRQ %d\n", dev->irq);
 455                         acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
 456                                           ACPI_ACTIVE_LOW);
 457                         return_VALUE(0);
 458                 } else {
 459                         printk("\n");
 460                         return_VALUE(0);
 461                 }
 462         }
 463
 464         rc = acpi_register_gsi(irq, triggering, polarity);
 465         if (rc < 0) {
 466                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
 467                        "to register GSI\n", pci_name(dev), ('A' + pin));
 468                 return_VALUE(rc);
 469         }
 470         dev->irq = rc;
 471
 472         printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
 473                pci_name(dev), 'A' + pin);
 474
 475         if (link)
 476                 printk("Link [%s] -> ", link);
 477
 478         printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
 479                (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
 480                (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
 481
 482         return_VALUE(0);
 483 }
 484
 485 EXPORT_SYMBOL(acpi_pci_irq_enable);
 486
 487 /* FIXME: implement x86/x86_64 version */
 488 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
 489 {
 490 }
 491
 492 void acpi_pci_irq_disable(struct pci_dev *dev)
 493 {
 494         int gsi = 0;
 495         u8 pin = 0;
 496         int triggering = ACPI_LEVEL_SENSITIVE;
 497         int polarity = ACPI_ACTIVE_LOW;
 498
 499         ACPI_FUNCTION_TRACE("acpi_pci_irq_disable");
 500
 501         if (!dev || !dev->bus)
 502                 return_VOID;
 503
 504         pin = dev->pin;
 505         if (!pin)
 506                 return_VOID;
 507         pin--;
 508
 509         /*
 510          * First we check the PCI IRQ routing table (PRT) for an IRQ.
 511          */
 512         gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 513                                   &triggering, &polarity, NULL,
 514                                   acpi_pci_free_irq);
 515         /*
 516          * If no PRT entry was found, we'll try to derive an IRQ from the
 517          * device's parent bridge.
 518          */
 519         if (gsi < 0)
 520                 gsi = acpi_pci_irq_derive(dev, pin,
 521                                           &triggering, &polarity, NULL,
 522                                           acpi_pci_free_irq);
 523         if (gsi < 0)
 524                 return_VOID;
 525
 526         /*
 527          * TBD: It might be worth clearing dev->irq by magic constant
 528          * (e.g. PCI_UNDEFINED_IRQ).
 529          */
 530
 531         printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
 532                pci_name(dev));
 533
 534         acpi_unregister_gsi(gsi);
 535
 536         return_VOID;
 537 }