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 #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 #ifdef CONFIG_X86_IO_APIC
  39 #include <asm/mpspec.h>
  40 #endif
  41 #ifdef CONFIG_IOSAPIC
  42 # include <asm/iosapic.h>
  43 #endif
  44 #include <acpi/acpi_bus.h>
  45 #include <acpi/acpi_drivers.h>
  46
  47
  48 #define _COMPONENT              ACPI_PCI_COMPONENT
  49 ACPI_MODULE_NAME                ("pci_irq")
  50
  51 #define PREFIX                  "PCI: "
  52
  53 struct acpi_prt_list            acpi_prt;
  54
  55 #ifdef CONFIG_X86
  56 extern void eisa_set_level_irq(unsigned int irq);
  57 #endif
  58
  59
  60 /* --------------------------------------------------------------------------
  61                          PCI IRQ Routing Table (PRT) Support
  62    -------------------------------------------------------------------------- */
  63
  64 static struct acpi_prt_entry *
  65 acpi_pci_irq_find_prt_entry (
  66         int                     segment,
  67         int                     bus,
  68         int                     device,
  69         int                     pin)
  70 {
  71         struct list_head        *node = NULL;
  72         struct acpi_prt_entry   *entry = NULL;
  73
  74         ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry");
  75
  76         if (!acpi_prt.count)
  77                 return_PTR(NULL);
  78
  79         /*
  80          * Parse through all PRT entries looking for a match on the specified
  81          * PCI device's segment, bus, device, and pin (don't care about func).
  82          *
  83          * TBD: Acquire/release lock
  84          */
  85         list_for_each(node, &acpi_prt.entries) {
  86                 entry = list_entry(node, struct acpi_prt_entry, node);
  87                 if ((segment == entry->id.segment)
  88                         && (bus == entry->id.bus)
  89                         && (device == entry->id.device)
  90                         && (pin == entry->pin)) {
  91                         return_PTR(entry);
  92                 }
  93         }
  94
  95         return_PTR(NULL);
  96 }
  97
  98
  99 static int
 100 acpi_pci_irq_add_entry (
 101         acpi_handle                     handle,
 102         int                             segment,
 103         int                             bus,
 104         struct acpi_pci_routing_table   *prt)
 105 {
 106         struct acpi_prt_entry   *entry = NULL;
 107
 108         ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry");
 109
 110         if (!prt)
 111                 return_VALUE(-EINVAL);
 112
 113         entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
 114         if (!entry)
 115                 return_VALUE(-ENOMEM);
 116         memset(entry, 0, sizeof(struct acpi_prt_entry));
 117
 118         entry->id.segment = segment;
 119         entry->id.bus = bus;
 120         entry->id.device = (prt->address >> 16) & 0xFFFF;
 121         entry->id.function = prt->address & 0xFFFF;
 122         entry->pin = prt->pin;
 123
 124         /*
 125          * Type 1: Dynamic
 126          * ---------------
 127          * The 'source' field specifies the PCI interrupt link device used to
 128          * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
 129          * indicates which resource descriptor in the resource template (of
 130          * the link device) this interrupt is allocated from.
 131          *
 132          * NOTE: Don't query the Link Device for IRQ information at this time
 133          *       because Link Device enumeration may not have occurred yet
 134          *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
 135          *       namespace).
 136          */
 137         if (prt->source[0]) {
 138                 acpi_get_handle(handle, prt->source, &entry->link.handle);
 139                 entry->link.index = prt->source_index;
 140         }
 141         /*
 142          * Type 2: Static
 143          * --------------
 144          * The 'source' field is NULL, and the 'source_index' field specifies
 145          * the IRQ value, which is hardwired to specific interrupt inputs on
 146          * the interrupt controller.
 147          */
 148         else
 149                 entry->link.index = prt->source_index;
 150
 151         ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
 152                 "      %02X:%02X:%02X[%c] -> %s[%d]\n",
 153                 entry->id.segment, entry->id.bus, entry->id.device,
 154                 ('A' + entry->pin), prt->source, entry->link.index));
 155
 156         /* TBD: Acquire/release lock */
 157         list_add_tail(&entry->node, &acpi_prt.entries);
 158         acpi_prt.count++;
 159
 160         return_VALUE(0);
 161 }
 162
 163
 164 int
 165 acpi_pci_irq_add_prt (
 166         acpi_handle             handle,
 167         int                     segment,
 168         int                     bus)
 169 {
 170         acpi_status                     status = AE_OK;
 171         char                            pathname[ACPI_PATHNAME_MAX] = {0};
 172         struct acpi_buffer              buffer = {0, NULL};
 173         struct acpi_pci_routing_table   *prt = NULL;
 174         struct acpi_pci_routing_table   *entry = NULL;
 175         static int                      first_time = 1;
 176
 177         ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt");
 178
 179         if (first_time) {
 180                 acpi_prt.count = 0;
 181                 INIT_LIST_HEAD(&acpi_prt.entries);
 182                 first_time = 0;
 183         }
 184
 185         /*
 186          * NOTE: We're given a 'handle' to the _PRT object's parent device
 187          *       (either a PCI root bridge or PCI-PCI bridge).
 188          */
 189
 190         buffer.length = sizeof(pathname);
 191         buffer.pointer = pathname;
 192         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 193
 194         printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
 195                 pathname);
 196
 197         /*
 198          * Evaluate this _PRT and add its entries to our global list (acpi_prt).
 199          */
 200
 201         buffer.length = 0;
 202         buffer.pointer = NULL;
 203         status = acpi_get_irq_routing_table(handle, &buffer);
 204         if (status != AE_BUFFER_OVERFLOW) {
 205                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
 206                         acpi_format_exception(status)));
 207                 return_VALUE(-ENODEV);
 208         }
 209
 210         prt = kmalloc(buffer.length, GFP_KERNEL);
 211         if (!prt)
 212                 return_VALUE(-ENOMEM);
 213         memset(prt, 0, buffer.length);
 214         buffer.pointer = prt;
 215
 216         status = acpi_get_irq_routing_table(handle, &buffer);
 217         if (ACPI_FAILURE(status)) {
 218                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
 219                         acpi_format_exception(status)));
 220                 kfree(buffer.pointer);
 221                 return_VALUE(-ENODEV);
 222         }
 223
 224         entry = prt;
 225
 226         while (entry && (entry->length > 0)) {
 227                 acpi_pci_irq_add_entry(handle, segment, bus, entry);
 228                 entry = (struct acpi_pci_routing_table *)
 229                         ((unsigned long) entry + entry->length);
 230         }
 231
 232         kfree(prt);
 233
 234         return_VALUE(0);
 235 }
 236
 237
 238 /* --------------------------------------------------------------------------
 239                           PCI Interrupt Routing Support
 240    -------------------------------------------------------------------------- */
 241
 242 int
 243 acpi_pci_irq_lookup (
 244         int                     segment,
 245         int                     bus,
 246         int                     device,
 247         int                     pin)
 248 {
 249         struct acpi_prt_entry   *entry = NULL;
 250
 251         ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");
 252
 253         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 254                 "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
 255                 segment, bus, device, ('A' + pin)));
 256
 257         entry = acpi_pci_irq_find_prt_entry(segment, bus, device, pin);
 258         if (!entry) {
 259                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
 260                 return_VALUE(0);
 261         }
 262
 263         if (!entry->irq && entry->link.handle) {
 264                 entry->irq = acpi_pci_link_get_irq(entry->link.handle, entry->link.index, NULL, NULL);
 265                 if (!entry->irq) {
 266                         ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n"));
 267                         return_VALUE(0);
 268                 }
 269         }
 270         else if (!entry->irq) {
 271                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid static routing entry (IRQ 0)\n"));
 272                 return_VALUE(0);
 273         }
 274
 275         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", entry->irq));
 276
 277         return_VALUE(entry->irq);
 278 }
 279
 280 static int
 281 acpi_pci_irq_derive (
 282         struct pci_dev          *dev,
 283         int                     pin)
 284 {
 285         struct pci_dev          *bridge = dev;
 286         int                     irq = 0;
 287         u8                      bridge_pin = 0;
 288
 289         ACPI_FUNCTION_TRACE("acpi_pci_irq_derive");
 290
 291         if (!dev)
 292                 return_VALUE(-EINVAL);
 293
 294         /*
 295          * Attempt to derive an IRQ for this device from a parent bridge's
 296          * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge)
 297          */
 298         while (!irq && bridge->bus->self) {
 299                 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
 300                 bridge = bridge->bus->self;
 301
 302                 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
 303                         /* PC card has the same IRQ as its cardbridge */
 304                         pci_read_config_byte(bridge, PCI_INTERRUPT_PIN, &bridge_pin);
 305                         if (!bridge_pin) {
 306                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 307                                         "No interrupt pin configured for device %s\n",
 308                                         pci_name(bridge)));
 309                                 return_VALUE(0);
 310                         }
 311                         /* Pin is from 0 to 3 */
 312                         bridge_pin --;
 313                         pin = bridge_pin;
 314                 }
 315
 316                 irq = acpi_pci_irq_lookup(0, bridge->bus->number,
 317                                 PCI_SLOT(bridge->devfn), pin);
 318         }
 319
 320         if (!irq) {
 321                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Unable to derive IRQ for device %s\n", dev->slot_name));
 322                 return_VALUE(0);
 323         }
 324
 325         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
 326                 irq, pci_name(dev), pci_name(bridge)));
 327
 328         return_VALUE(irq);
 329 }
 330
 331
 332 int
 333 acpi_pci_irq_enable (
 334         struct pci_dev          *dev)
 335 {
 336         int                     irq = 0;
 337         u8                      pin = 0;
 338         extern int via_interrupt_line_quirk;
 339
 340         ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
 341
 342         if (!dev)
 343                 return_VALUE(-EINVAL);
 344
 345         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 346         if (!pin) {
 347                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", dev->slot_name));
 348                 return_VALUE(0);
 349         }
 350         pin--;
 351
 352         if (!dev->bus) {
 353                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n"));
 354                 return_VALUE(-ENODEV);
 355         }
 356
 357         /*
 358          * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
 359          * values override any BIOS-assigned IRQs set during boot.
 360          */
 361         irq = acpi_pci_irq_lookup(0, dev->bus->number, PCI_SLOT(dev->devfn), pin);
 362
 363         /*
 364          * If no PRT entry was found, we'll try to derive an IRQ from the
 365          * device's parent bridge.
 366          */
 367         if (!irq)
 368                 irq = acpi_pci_irq_derive(dev, pin);
 369
 370         /*
 371          * No IRQ known to the ACPI subsystem - maybe the BIOS /
 372          * driver reported one, then use it. Exit in any case.
 373          */
 374         if (!irq) {
 375                 printk(KERN_WARNING PREFIX "No IRQ known for interrupt pin %c of device %s", ('A' + pin), dev->slot_name);
 376                 /* Interrupt Line values above 0xF are forbidden */
 377                 if (dev->irq && (dev->irq <= 0xF)) {
 378                         printk(" - using IRQ %d\n", dev->irq);
 379                         return_VALUE(dev->irq);
 380                 }
 381                 else {
 382                         printk("\n");
 383                         return_VALUE(0);
 384                 }
 385         }
 386
 387         if (via_interrupt_line_quirk)
 388                 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq & 15);
 389
 390         dev->irq = irq;
 391
 392         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device %s using IRQ %d\n", dev->slot_name, dev->irq));
 393
 394         /*
 395          * Make sure all (legacy) PCI IRQs are set as level-triggered.
 396          */
 397 #ifdef CONFIG_X86
 398         {
 399                 static u16 irq_mask;
 400                 if ((dev->irq < 16) &&  !((1 << dev->irq) & irq_mask)) {
 401                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Setting IRQ %d as level-triggered\n", dev->irq));
 402                         irq_mask |= (1 << dev->irq);
 403                         eisa_set_level_irq(dev->irq);
 404                 }
 405         }
 406 #endif
 407 #ifdef CONFIG_IOSAPIC
 408         if (acpi_irq_model == ACPI_IRQ_MODEL_IOSAPIC)
 409                 iosapic_enable_intr(dev->irq);
 410 #endif
 411
 412         return_VALUE(dev->irq);
 413 }
 414
 415
 416 int __init
 417 acpi_pci_irq_init (void)
 418 {
 419         struct pci_dev          *dev = NULL;
 420
 421         ACPI_FUNCTION_TRACE("acpi_pci_irq_init");
 422
 423         if (!acpi_prt.count) {
 424                 printk(KERN_WARNING PREFIX "ACPI tables contain no PCI IRQ "
 425                         "routing entries\n");
 426                 return_VALUE(-ENODEV);
 427         }
 428
 429         /* Make sure all link devices have a valid IRQ. */
 430         if (acpi_pci_link_check()) {
 431                 return_VALUE(-ENODEV);
 432         }
 433
 434 #ifdef CONFIG_X86_IO_APIC
 435         /* Program IOAPICs using data from PRT entries. */
 436         if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
 437                 mp_parse_prt();
 438 #endif
 439 #ifdef CONFIG_IOSAPIC
 440         if (acpi_irq_model == ACPI_IRQ_MODEL_IOSAPIC)
 441                 iosapic_parse_prt();
 442 #endif
 443
 444         pci_for_each_dev(dev)
 445                 acpi_pci_irq_enable(dev);
 446
 447         return_VALUE(0);
 448 }