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