linux/drivers/acpi/pci_root.c
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   1/*
   2 *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
   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 *
   7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8 *
   9 *  This program is free software; you can redistribute it and/or modify
  10 *  it under the terms of the GNU General Public License as published by
  11 *  the Free Software Foundation; either version 2 of the License, or (at
  12 *  your option) any later version.
  13 *
  14 *  This program is distributed in the hope that it will be useful, but
  15 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 *  General Public License for more details.
  18 *
  19 *  You should have received a copy of the GNU General Public License along
  20 *  with this program; if not, write to the Free Software Foundation, Inc.,
  21 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22 *
  23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24 */
  25
  26#include <linux/kernel.h>
  27#include <linux/module.h>
  28#include <linux/init.h>
  29#include <linux/types.h>
  30#include <linux/proc_fs.h>
  31#include <linux/spinlock.h>
  32#include <linux/pm.h>
  33#include <linux/pci.h>
  34#include <linux/acpi.h>
  35#include <acpi/acpi_bus.h>
  36#include <acpi/acpi_drivers.h>
  37
  38#define _COMPONENT              ACPI_PCI_COMPONENT
  39ACPI_MODULE_NAME("pci_root");
  40#define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  41#define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  42static int acpi_pci_root_add(struct acpi_device *device);
  43static int acpi_pci_root_remove(struct acpi_device *device, int type);
  44static int acpi_pci_root_start(struct acpi_device *device);
  45
  46static struct acpi_device_id root_device_ids[] = {
  47        {"PNP0A03", 0},
  48        {"", 0},
  49};
  50MODULE_DEVICE_TABLE(acpi, root_device_ids);
  51
  52static struct acpi_driver acpi_pci_root_driver = {
  53        .name = "pci_root",
  54        .class = ACPI_PCI_ROOT_CLASS,
  55        .ids = root_device_ids,
  56        .ops = {
  57                .add = acpi_pci_root_add,
  58                .remove = acpi_pci_root_remove,
  59                .start = acpi_pci_root_start,
  60                },
  61};
  62
  63struct acpi_pci_root {
  64        struct list_head node;
  65        struct acpi_device * device;
  66        struct acpi_pci_id id;
  67        struct pci_bus *bus;
  68};
  69
  70static LIST_HEAD(acpi_pci_roots);
  71
  72static struct acpi_pci_driver *sub_driver;
  73
  74int acpi_pci_register_driver(struct acpi_pci_driver *driver)
  75{
  76        int n = 0;
  77        struct list_head *entry;
  78
  79        struct acpi_pci_driver **pptr = &sub_driver;
  80        while (*pptr)
  81                pptr = &(*pptr)->next;
  82        *pptr = driver;
  83
  84        if (!driver->add)
  85                return 0;
  86
  87        list_for_each(entry, &acpi_pci_roots) {
  88                struct acpi_pci_root *root;
  89                root = list_entry(entry, struct acpi_pci_root, node);
  90                driver->add(root->device->handle);
  91                n++;
  92        }
  93
  94        return n;
  95}
  96
  97EXPORT_SYMBOL(acpi_pci_register_driver);
  98
  99void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
 100{
 101        struct list_head *entry;
 102
 103        struct acpi_pci_driver **pptr = &sub_driver;
 104        while (*pptr) {
 105                if (*pptr == driver)
 106                        break;
 107                pptr = &(*pptr)->next;
 108        }
 109        BUG_ON(!*pptr);
 110        *pptr = (*pptr)->next;
 111
 112        if (!driver->remove)
 113                return;
 114
 115        list_for_each(entry, &acpi_pci_roots) {
 116                struct acpi_pci_root *root;
 117                root = list_entry(entry, struct acpi_pci_root, node);
 118                driver->remove(root->device->handle);
 119        }
 120}
 121
 122EXPORT_SYMBOL(acpi_pci_unregister_driver);
 123
 124acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 125{
 126        struct acpi_pci_root *tmp;
 127        
 128        list_for_each_entry(tmp, &acpi_pci_roots, node) {
 129                if ((tmp->id.segment == (u16) seg) && (tmp->id.bus == (u16) bus))
 130                        return tmp->device->handle;
 131        }
 132        return NULL;            
 133}
 134
 135EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
 136
 137static acpi_status
 138get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 139{
 140        int *busnr = data;
 141        struct acpi_resource_address64 address;
 142
 143        if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
 144            resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
 145            resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
 146                return AE_OK;
 147
 148        acpi_resource_to_address64(resource, &address);
 149        if ((address.address_length > 0) &&
 150            (address.resource_type == ACPI_BUS_NUMBER_RANGE))
 151                *busnr = address.minimum;
 152
 153        return AE_OK;
 154}
 155
 156static acpi_status try_get_root_bridge_busnr(acpi_handle handle, int *busnum)
 157{
 158        acpi_status status;
 159
 160        *busnum = -1;
 161        status =
 162            acpi_walk_resources(handle, METHOD_NAME__CRS,
 163                                get_root_bridge_busnr_callback, busnum);
 164        if (ACPI_FAILURE(status))
 165                return status;
 166        /* Check if we really get a bus number from _CRS */
 167        if (*busnum == -1)
 168                return AE_ERROR;
 169        return AE_OK;
 170}
 171
 172static void acpi_pci_bridge_scan(struct acpi_device *device)
 173{
 174        int status;
 175        struct acpi_device *child = NULL;
 176
 177        if (device->flags.bus_address)
 178                if (device->parent && device->parent->ops.bind) {
 179                        status = device->parent->ops.bind(device);
 180                        if (!status) {
 181                                list_for_each_entry(child, &device->children, node)
 182                                        acpi_pci_bridge_scan(child);
 183                        }
 184                }
 185}
 186
 187static int __devinit acpi_pci_root_add(struct acpi_device *device)
 188{
 189        int result = 0;
 190        struct acpi_pci_root *root = NULL;
 191        struct acpi_pci_root *tmp;
 192        acpi_status status = AE_OK;
 193        unsigned long long value = 0;
 194        acpi_handle handle = NULL;
 195        struct acpi_device *child;
 196
 197
 198        if (!device)
 199                return -EINVAL;
 200
 201        root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 202        if (!root)
 203                return -ENOMEM;
 204        INIT_LIST_HEAD(&root->node);
 205
 206        root->device = device;
 207        strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 208        strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 209        device->driver_data = root;
 210
 211        device->ops.bind = acpi_pci_bind;
 212
 213        /* 
 214         * Segment
 215         * -------
 216         * Obtained via _SEG, if exists, otherwise assumed to be zero (0).
 217         */
 218        status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
 219                                       &value);
 220        switch (status) {
 221        case AE_OK:
 222                root->id.segment = (u16) value;
 223                break;
 224        case AE_NOT_FOUND:
 225                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 226                                  "Assuming segment 0 (no _SEG)\n"));
 227                root->id.segment = 0;
 228                break;
 229        default:
 230                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SEG"));
 231                result = -ENODEV;
 232                goto end;
 233        }
 234
 235        /* 
 236         * Bus
 237         * ---
 238         * Obtained via _BBN, if exists, otherwise assumed to be zero (0).
 239         */
 240        status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL,
 241                                       &value);
 242        switch (status) {
 243        case AE_OK:
 244                root->id.bus = (u16) value;
 245                break;
 246        case AE_NOT_FOUND:
 247                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Assuming bus 0 (no _BBN)\n"));
 248                root->id.bus = 0;
 249                break;
 250        default:
 251                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BBN"));
 252                result = -ENODEV;
 253                goto end;
 254        }
 255
 256        /* Some systems have wrong _BBN */
 257        list_for_each_entry(tmp, &acpi_pci_roots, node) {
 258                if ((tmp->id.segment == root->id.segment)
 259                    && (tmp->id.bus == root->id.bus)) {
 260                        int bus = 0;
 261                        acpi_status status;
 262
 263                        printk(KERN_ERR PREFIX
 264                                    "Wrong _BBN value, reboot"
 265                                    " and use option 'pci=noacpi'\n");
 266
 267                        status = try_get_root_bridge_busnr(device->handle, &bus);
 268                        if (ACPI_FAILURE(status))
 269                                break;
 270                        if (bus != root->id.bus) {
 271                                printk(KERN_INFO PREFIX
 272                                       "PCI _CRS %d overrides _BBN 0\n", bus);
 273                                root->id.bus = bus;
 274                        }
 275                        break;
 276                }
 277        }
 278        /*
 279         * Device & Function
 280         * -----------------
 281         * Obtained from _ADR (which has already been evaluated for us).
 282         */
 283        root->id.device = device->pnp.bus_address >> 16;
 284        root->id.function = device->pnp.bus_address & 0xFFFF;
 285
 286        /*
 287         * TBD: Need PCI interface for enumeration/configuration of roots.
 288         */
 289
 290        /* TBD: Locking */
 291        list_add_tail(&root->node, &acpi_pci_roots);
 292
 293        printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
 294               acpi_device_name(device), acpi_device_bid(device),
 295               root->id.segment, root->id.bus);
 296
 297        /*
 298         * Scan the Root Bridge
 299         * --------------------
 300         * Must do this prior to any attempt to bind the root device, as the
 301         * PCI namespace does not get created until this call is made (and 
 302         * thus the root bridge's pci_dev does not exist).
 303         */
 304        root->bus = pci_acpi_scan_root(device, root->id.segment, root->id.bus);
 305        if (!root->bus) {
 306                printk(KERN_ERR PREFIX
 307                            "Bus %04x:%02x not present in PCI namespace\n",
 308                            root->id.segment, root->id.bus);
 309                result = -ENODEV;
 310                goto end;
 311        }
 312
 313        /*
 314         * Attach ACPI-PCI Context
 315         * -----------------------
 316         * Thus binding the ACPI and PCI devices.
 317         */
 318        result = acpi_pci_bind_root(device, &root->id, root->bus);
 319        if (result)
 320                goto end;
 321
 322        /*
 323         * PCI Routing Table
 324         * -----------------
 325         * Evaluate and parse _PRT, if exists.
 326         */
 327        status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
 328        if (ACPI_SUCCESS(status))
 329                result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
 330                                              root->id.bus);
 331
 332        /*
 333         * Scan and bind all _ADR-Based Devices
 334         */
 335        list_for_each_entry(child, &device->children, node)
 336                acpi_pci_bridge_scan(child);
 337
 338      end:
 339        if (result) {
 340                if (!list_empty(&root->node))
 341                        list_del(&root->node);
 342                kfree(root);
 343        }
 344
 345        return result;
 346}
 347
 348static int acpi_pci_root_start(struct acpi_device *device)
 349{
 350        struct acpi_pci_root *root;
 351
 352
 353        list_for_each_entry(root, &acpi_pci_roots, node) {
 354                if (root->device == device) {
 355                        pci_bus_add_devices(root->bus);
 356                        return 0;
 357                }
 358        }
 359        return -ENODEV;
 360}
 361
 362static int acpi_pci_root_remove(struct acpi_device *device, int type)
 363{
 364        struct acpi_pci_root *root = NULL;
 365
 366
 367        if (!device || !acpi_driver_data(device))
 368                return -EINVAL;
 369
 370        root = acpi_driver_data(device);
 371
 372        kfree(root);
 373
 374        return 0;
 375}
 376
 377static int __init acpi_pci_root_init(void)
 378{
 379        if (acpi_pci_disabled)
 380                return 0;
 381
 382        if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
 383                return -ENODEV;
 384
 385        return 0;
 386}
 387
 388subsys_initcall(acpi_pci_root_init);
 389
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