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