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