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