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 acpi_prt_entry *entry = NULL;
  55
  56         if (!acpi_prt.count)
  57                 return NULL;
  58
  59         /*
  60          * Parse through all PRT entries looking for a match on the specified
  61          * PCI device's segment, bus, device, and pin (don't care about func).
  62          *
  63          */
  64         spin_lock(&acpi_prt_lock);
  65         list_for_each_entry(entry, &acpi_prt.entries, node) {
  66                 if ((segment == entry->id.segment)
  67                     && (bus == entry->id.bus)
  68                     && (device == entry->id.device)
  69                     && (pin == entry->pin)) {
  70                         spin_unlock(&acpi_prt_lock);
  71                         return entry;
  72                 }
  73         }
  74
  75         spin_unlock(&acpi_prt_lock);
  76         return NULL;
  77 }
  78
  79 static int
  80 acpi_pci_irq_add_entry(acpi_handle handle,
  81                        int segment, int bus, struct acpi_pci_routing_table *prt)
  82 {
  83         struct acpi_prt_entry *entry = NULL;
  84
  85
  86         if (!prt)
  87                 return -EINVAL;
  88
  89         entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
  90         if (!entry)
  91                 return -ENOMEM;
  92
  93         entry->id.segment = segment;
  94         entry->id.bus = bus;
  95         entry->id.device = (prt->address >> 16) & 0xFFFF;
  96         entry->id.function = prt->address & 0xFFFF;
  97         entry->pin = prt->pin;
  98
  99         /*
 100          * Type 1: Dynamic
 101          * ---------------
 102          * The 'source' field specifies the PCI interrupt link device used to
 103          * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
 104          * indicates which resource descriptor in the resource template (of
 105          * the link device) this interrupt is allocated from.
 106          *
 107          * NOTE: Don't query the Link Device for IRQ information at this time
 108          *       because Link Device enumeration may not have occurred yet
 109          *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
 110          *       namespace).
 111          */
 112         if (prt->source[0]) {
 113                 acpi_get_handle(handle, prt->source, &entry->link.handle);
 114                 entry->link.index = prt->source_index;
 115         }
 116         /*
 117          * Type 2: Static
 118          * --------------
 119          * The 'source' field is NULL, and the 'source_index' field specifies
 120          * the IRQ value, which is hardwired to specific interrupt inputs on
 121          * the interrupt controller.
 122          */
 123         else
 124                 entry->link.index = prt->source_index;
 125
 126         ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
 127                               "      %02X:%02X:%02X[%c] -> %s[%d]\n",
 128                               entry->id.segment, entry->id.bus,
 129                               entry->id.device, ('A' + entry->pin), prt->source,
 130                               entry->link.index));
 131
 132         spin_lock(&acpi_prt_lock);
 133         list_add_tail(&entry->node, &acpi_prt.entries);
 134         acpi_prt.count++;
 135         spin_unlock(&acpi_prt_lock);
 136
 137         return 0;
 138 }
 139
 140 static void
 141 acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry)
 142 {
 143         if (segment == entry->id.segment && bus == entry->id.bus) {
 144                 acpi_prt.count--;
 145                 list_del(&entry->node);
 146                 kfree(entry);
 147         }
 148 }
 149
 150 int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
 151 {
 152         acpi_status status = AE_OK;
 153         char *pathname = NULL;
 154         struct acpi_buffer buffer = { 0, NULL };
 155         struct acpi_pci_routing_table *prt = NULL;
 156         struct acpi_pci_routing_table *entry = NULL;
 157         static int first_time = 1;
 158
 159
 160         pathname = kzalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
 161         if (!pathname)
 162                 return -ENOMEM;
 163
 164         if (first_time) {
 165                 acpi_prt.count = 0;
 166                 INIT_LIST_HEAD(&acpi_prt.entries);
 167                 first_time = 0;
 168         }
 169
 170         /*
 171          * NOTE: We're given a 'handle' to the _PRT object's parent device
 172          *       (either a PCI root bridge or PCI-PCI bridge).
 173          */
 174
 175         buffer.length = ACPI_PATHNAME_MAX;
 176         buffer.pointer = pathname;
 177         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 178
 179         printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
 180                pathname);
 181
 182         /*
 183          * Evaluate this _PRT and add its entries to our global list (acpi_prt).
 184          */
 185
 186         buffer.length = 0;
 187         buffer.pointer = NULL;
 188         kfree(pathname);
 189         status = acpi_get_irq_routing_table(handle, &buffer);
 190         if (status != AE_BUFFER_OVERFLOW) {
 191                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
 192                                 acpi_format_exception(status)));
 193                 return -ENODEV;
 194         }
 195
 196         prt = kzalloc(buffer.length, GFP_KERNEL);
 197         if (!prt) {
 198                 return -ENOMEM;
 199         }
 200         buffer.pointer = prt;
 201
 202         status = acpi_get_irq_routing_table(handle, &buffer);
 203         if (ACPI_FAILURE(status)) {
 204                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
 205                                 acpi_format_exception(status)));
 206                 kfree(buffer.pointer);
 207                 return -ENODEV;
 208         }
 209
 210         entry = prt;
 211
 212         while (entry && (entry->length > 0)) {
 213                 acpi_pci_irq_add_entry(handle, segment, bus, entry);
 214                 entry = (struct acpi_pci_routing_table *)
 215                     ((unsigned long)entry + entry->length);
 216         }
 217
 218         kfree(prt);
 219
 220         return 0;
 221 }
 222
 223 void acpi_pci_irq_del_prt(int segment, int bus)
 224 {
 225         struct list_head *node = NULL, *n = NULL;
 226         struct acpi_prt_entry *entry = NULL;
 227
 228         if (!acpi_prt.count) {
 229                 return;
 230         }
 231
 232         printk(KERN_DEBUG
 233                "ACPI: Delete PCI Interrupt Routing Table for %x:%x\n", segment,
 234                bus);
 235         spin_lock(&acpi_prt_lock);
 236         list_for_each_safe(node, n, &acpi_prt.entries) {
 237                 entry = list_entry(node, struct acpi_prt_entry, node);
 238
 239                 acpi_pci_irq_del_entry(segment, bus, entry);
 240         }
 241         spin_unlock(&acpi_prt_lock);
 242 }
 243
 244 /* --------------------------------------------------------------------------
 245                           PCI Interrupt Routing Support
 246    -------------------------------------------------------------------------- */
 247 typedef int (*irq_lookup_func) (struct acpi_prt_entry *, int *, int *, char **);
 248
 249 static int
 250 acpi_pci_allocate_irq(struct acpi_prt_entry *entry,
 251                       int *triggering, int *polarity, char **link)
 252 {
 253         int irq;
 254
 255
 256         if (entry->link.handle) {
 257                 irq = acpi_pci_link_allocate_irq(entry->link.handle,
 258                                                  entry->link.index, triggering,
 259                                                  polarity, link);
 260                 if (irq < 0) {
 261                         printk(KERN_WARNING PREFIX
 262                                       "Invalid IRQ link routing entry\n");
 263                         return -1;
 264                 }
 265         } else {
 266                 irq = entry->link.index;
 267                 *triggering = ACPI_LEVEL_SENSITIVE;
 268                 *polarity = ACPI_ACTIVE_LOW;
 269         }
 270
 271         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", irq));
 272         return irq;
 273 }
 274
 275 static int
 276 acpi_pci_free_irq(struct acpi_prt_entry *entry,
 277                   int *triggering, int *polarity, char **link)
 278 {
 279         int irq;
 280
 281         if (entry->link.handle) {
 282                 irq = acpi_pci_link_free_irq(entry->link.handle);
 283         } else {
 284                 irq = entry->link.index;
 285         }
 286         return irq;
 287 }
 288
 289 /*
 290  * acpi_pci_irq_lookup
 291  * success: return IRQ >= 0
 292  * failure: return -1
 293  */
 294 static int
 295 acpi_pci_irq_lookup(struct pci_bus *bus,
 296                     int device,
 297                     int pin,
 298                     int *triggering,
 299                     int *polarity, char **link, irq_lookup_func func)
 300 {
 301         struct acpi_prt_entry *entry = NULL;
 302         int segment = pci_domain_nr(bus);
 303         int bus_nr = bus->number;
 304         int ret;
 305
 306
 307         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 308                           "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
 309                           segment, bus_nr, device, ('A' + pin)));
 310
 311         entry = acpi_pci_irq_find_prt_entry(segment, bus_nr, device, pin);
 312         if (!entry) {
 313                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
 314                 return -1;
 315         }
 316
 317         ret = func(entry, triggering, polarity, link);
 318         return ret;
 319 }
 320
 321 /*
 322  * acpi_pci_irq_derive
 323  * success: return IRQ >= 0
 324  * failure: return < 0
 325  */
 326 static int
 327 acpi_pci_irq_derive(struct pci_dev *dev,
 328                     int pin,
 329                     int *triggering,
 330                     int *polarity, char **link, irq_lookup_func func)
 331 {
 332         struct pci_dev *bridge = dev;
 333         int irq = -1;
 334         u8 bridge_pin = 0;
 335
 336
 337         if (!dev)
 338                 return -EINVAL;
 339
 340         /*
 341          * Attempt to derive an IRQ for this device from a parent bridge's
 342          * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
 343          */
 344         while (irq < 0 && bridge->bus->self) {
 345                 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
 346                 bridge = bridge->bus->self;
 347
 348                 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
 349                         /* PC card has the same IRQ as its cardbridge */
 350                         bridge_pin = bridge->pin;
 351                         if (!bridge_pin) {
 352                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 353                                                   "No interrupt pin configured for device %s\n",
 354                                                   pci_name(bridge)));
 355                                 return -1;
 356                         }
 357                         /* Pin is from 0 to 3 */
 358                         bridge_pin--;
 359                         pin = bridge_pin;
 360                 }
 361
 362                 irq = acpi_pci_irq_lookup(bridge->bus, PCI_SLOT(bridge->devfn),
 363                                           pin, triggering, polarity,
 364                                           link, func);
 365         }
 366
 367         if (irq < 0) {
 368                 printk(KERN_WARNING PREFIX "Unable to derive IRQ for device %s\n",
 369                               pci_name(dev));
 370                 return -1;
 371         }
 372
 373         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
 374                           irq, pci_name(dev), pci_name(bridge)));
 375
 376         return irq;
 377 }
 378
 379 /*
 380  * acpi_pci_irq_enable
 381  * success: return 0
 382  * failure: return < 0
 383  */
 384
 385 int acpi_pci_irq_enable(struct pci_dev *dev)
 386 {
 387         int irq = 0;
 388         u8 pin = 0;
 389         int triggering = ACPI_LEVEL_SENSITIVE;
 390         int polarity = ACPI_ACTIVE_LOW;
 391         char *link = NULL;
 392         int rc;
 393
 394
 395         if (!dev)
 396                 return -EINVAL;
 397
 398         pin = dev->pin;
 399         if (!pin) {
 400                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 401                                   "No interrupt pin configured for device %s\n",
 402                                   pci_name(dev)));
 403                 return 0;
 404         }
 405         pin--;
 406
 407         if (!dev->bus) {
 408                 printk(KERN_ERR PREFIX "Invalid (NULL) 'bus' field\n");
 409                 return -ENODEV;
 410         }
 411
 412         /*
 413          * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
 414          * values override any BIOS-assigned IRQs set during boot.
 415          */
 416         irq = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 417                                   &triggering, &polarity, &link,
 418                                   acpi_pci_allocate_irq);
 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, &triggering,
 426                                           &polarity, &link,
 427                                           acpi_pci_allocate_irq);
 428
 429         if (irq < 0) {
 430                 /*
 431                  * IDE legacy mode controller IRQs are magic. Why do compat
 432                  * extensions always make such a nasty mess.
 433                  */
 434                 if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
 435                                 (dev->class & 0x05) == 0)
 436                         return 0;
 437         }
 438         /*
 439          * No IRQ known to the ACPI subsystem - maybe the BIOS /
 440          * driver reported one, then use it. Exit in any case.
 441          */
 442         if (irq < 0) {
 443                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
 444                        pci_name(dev), ('A' + pin));
 445                 /* Interrupt Line values above 0xF are forbidden */
 446                 if (dev->irq > 0 && (dev->irq <= 0xF)) {
 447                         printk(" - using IRQ %d\n", dev->irq);
 448                         acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE,
 449                                           ACPI_ACTIVE_LOW);
 450                         return 0;
 451                 } else {
 452                         printk("\n");
 453                         return 0;
 454                 }
 455         }
 456
 457         rc = acpi_register_gsi(irq, triggering, polarity);
 458         if (rc < 0) {
 459                 printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: failed "
 460                        "to register GSI\n", pci_name(dev), ('A' + pin));
 461                 return rc;
 462         }
 463         dev->irq = rc;
 464
 465         printk(KERN_INFO PREFIX "PCI Interrupt %s[%c] -> ",
 466                pci_name(dev), 'A' + pin);
 467
 468         if (link)
 469                 printk("Link [%s] -> ", link);
 470
 471         printk("GSI %u (%s, %s) -> IRQ %d\n", irq,
 472                (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
 473                (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
 474
 475         return 0;
 476 }
 477
 478 /* FIXME: implement x86/x86_64 version */
 479 void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
 480 {
 481 }
 482
 483 void acpi_pci_irq_disable(struct pci_dev *dev)
 484 {
 485         int gsi = 0;
 486         u8 pin = 0;
 487         int triggering = ACPI_LEVEL_SENSITIVE;
 488         int polarity = ACPI_ACTIVE_LOW;
 489
 490
 491         if (!dev || !dev->bus)
 492                 return;
 493
 494         pin = dev->pin;
 495         if (!pin)
 496                 return;
 497         pin--;
 498
 499         /*
 500          * First we check the PCI IRQ routing table (PRT) for an IRQ.
 501          */
 502         gsi = acpi_pci_irq_lookup(dev->bus, PCI_SLOT(dev->devfn), pin,
 503                                   &triggering, &polarity, NULL,
 504                                   acpi_pci_free_irq);
 505         /*
 506          * If no PRT entry was found, we'll try to derive an IRQ from the
 507          * device's parent bridge.
 508          */
 509         if (gsi < 0)
 510                 gsi = acpi_pci_irq_derive(dev, pin,
 511                                           &triggering, &polarity, NULL,
 512                                           acpi_pci_free_irq);
 513         if (gsi < 0)
 514                 return;
 515
 516         /*
 517          * TBD: It might be worth clearing dev->irq by magic constant
 518          * (e.g. PCI_UNDEFINED_IRQ).
 519          */
 520
 521         printk(KERN_INFO PREFIX "PCI interrupt for device %s disabled\n",
 522                pci_name(dev));
 523
 524         acpi_unregister_gsi(gsi);
 525
 526         return;
 527 }