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pci_root.c

/*
 *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/pm.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#define _COMPONENT            ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_root");
#define ACPI_PCI_ROOT_CLASS         "pci_bridge"
#define ACPI_PCI_ROOT_DEVICE_NAME   "PCI Root Bridge"
static int acpi_pci_root_add(struct acpi_device *device);
static int acpi_pci_root_remove(struct acpi_device *device, int type);
static int acpi_pci_root_start(struct acpi_device *device);

static struct acpi_device_id root_device_ids[] = {
      {"PNP0A03", 0},
      {"", 0},
};
MODULE_DEVICE_TABLE(acpi, root_device_ids);

static struct acpi_driver acpi_pci_root_driver = {
      .name = "pci_root",
      .class = ACPI_PCI_ROOT_CLASS,
      .ids = root_device_ids,
      .ops = {
            .add = acpi_pci_root_add,
            .remove = acpi_pci_root_remove,
            .start = acpi_pci_root_start,
            },
};

struct acpi_pci_root {
      struct list_head node;
      struct acpi_device * device;
      struct acpi_pci_id id;
      struct pci_bus *bus;
};

static LIST_HEAD(acpi_pci_roots);

static struct acpi_pci_driver *sub_driver;

int acpi_pci_register_driver(struct acpi_pci_driver *driver)
{
      int n = 0;
      struct list_head *entry;

      struct acpi_pci_driver **pptr = &sub_driver;
      while (*pptr)
            pptr = &(*pptr)->next;
      *pptr = driver;

      if (!driver->add)
            return 0;

      list_for_each(entry, &acpi_pci_roots) {
            struct acpi_pci_root *root;
            root = list_entry(entry, struct acpi_pci_root, node);
            driver->add(root->device->handle);
            n++;
      }

      return n;
}

EXPORT_SYMBOL(acpi_pci_register_driver);

void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
{
      struct list_head *entry;

      struct acpi_pci_driver **pptr = &sub_driver;
      while (*pptr) {
            if (*pptr == driver)
                  break;
            pptr = &(*pptr)->next;
      }
      BUG_ON(!*pptr);
      *pptr = (*pptr)->next;

      if (!driver->remove)
            return;

      list_for_each(entry, &acpi_pci_roots) {
            struct acpi_pci_root *root;
            root = list_entry(entry, struct acpi_pci_root, node);
            driver->remove(root->device->handle);
      }
}

EXPORT_SYMBOL(acpi_pci_unregister_driver);

acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
{
      struct acpi_pci_root *tmp;
      
      list_for_each_entry(tmp, &acpi_pci_roots, node) {
            if ((tmp->id.segment == (u16) seg) && (tmp->id.bus == (u16) bus))
                  return tmp->device->handle;
      }
      return NULL;            
}

EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);

static acpi_status
get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
{
      int *busnr = data;
      struct acpi_resource_address64 address;

      if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
          resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
          resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
            return AE_OK;

      acpi_resource_to_address64(resource, &address);
      if ((address.address_length > 0) &&
          (address.resource_type == ACPI_BUS_NUMBER_RANGE))
            *busnr = address.minimum;

      return AE_OK;
}

static acpi_status try_get_root_bridge_busnr(acpi_handle handle, int *busnum)
{
      acpi_status status;

      *busnum = -1;
      status =
          acpi_walk_resources(handle, METHOD_NAME__CRS,
                        get_root_bridge_busnr_callback, busnum);
      if (ACPI_FAILURE(status))
            return status;
      /* Check if we really get a bus number from _CRS */
      if (*busnum == -1)
            return AE_ERROR;
      return AE_OK;
}

static void acpi_pci_bridge_scan(struct acpi_device *device)
{
      int status;
      struct acpi_device *child = NULL;

      if (device->flags.bus_address)
            if (device->parent && device->parent->ops.bind) {
                  status = device->parent->ops.bind(device);
                  if (!status) {
                        list_for_each_entry(child, &device->children, node)
                              acpi_pci_bridge_scan(child);
                  }
            }
}

static int acpi_pci_root_add(struct acpi_device *device)
{
      int result = 0;
      struct acpi_pci_root *root = NULL;
      struct acpi_pci_root *tmp;
      acpi_status status = AE_OK;
      unsigned long value = 0;
      acpi_handle handle = NULL;
      struct acpi_device *child;


      if (!device)
            return -EINVAL;

      root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
      if (!root)
            return -ENOMEM;
      INIT_LIST_HEAD(&root->node);

      root->device = device;
      strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
      strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
      acpi_driver_data(device) = root;

      device->ops.bind = acpi_pci_bind;

      /* 
       * Segment
       * -------
       * Obtained via _SEG, if exists, otherwise assumed to be zero (0).
       */
      status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
                               &value);
      switch (status) {
      case AE_OK:
            root->id.segment = (u16) value;
            break;
      case AE_NOT_FOUND:
            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Assuming segment 0 (no _SEG)\n"));
            root->id.segment = 0;
            break;
      default:
            ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SEG"));
            result = -ENODEV;
            goto end;
      }

      /* 
       * Bus
       * ---
       * Obtained via _BBN, if exists, otherwise assumed to be zero (0).
       */
      status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL,
                               &value);
      switch (status) {
      case AE_OK:
            root->id.bus = (u16) value;
            break;
      case AE_NOT_FOUND:
            ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Assuming bus 0 (no _BBN)\n"));
            root->id.bus = 0;
            break;
      default:
            ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BBN"));
            result = -ENODEV;
            goto end;
      }

      /* Some systems have wrong _BBN */
      list_for_each_entry(tmp, &acpi_pci_roots, node) {
            if ((tmp->id.segment == root->id.segment)
                && (tmp->id.bus == root->id.bus)) {
                  int bus = 0;
                  acpi_status status;

                  printk(KERN_ERR PREFIX
                            "Wrong _BBN value, reboot"
                            " and use option 'pci=noacpi'\n");

                  status = try_get_root_bridge_busnr(device->handle, &bus);
                  if (ACPI_FAILURE(status))
                        break;
                  if (bus != root->id.bus) {
                        printk(KERN_INFO PREFIX
                               "PCI _CRS %d overrides _BBN 0\n", bus);
                        root->id.bus = bus;
                  }
                  break;
            }
      }
      /*
       * Device & Function
       * -----------------
       * Obtained from _ADR (which has already been evaluated for us).
       */
      root->id.device = device->pnp.bus_address >> 16;
      root->id.function = device->pnp.bus_address & 0xFFFF;

      /*
       * TBD: Need PCI interface for enumeration/configuration of roots.
       */

      /* TBD: Locking */
      list_add_tail(&root->node, &acpi_pci_roots);

      printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
             acpi_device_name(device), acpi_device_bid(device),
             root->id.segment, root->id.bus);

      /*
       * Scan the Root Bridge
       * --------------------
       * Must do this prior to any attempt to bind the root device, as the
       * PCI namespace does not get created until this call is made (and 
       * thus the root bridge's pci_dev does not exist).
       */
      root->bus = pci_acpi_scan_root(device, root->id.segment, root->id.bus);
      if (!root->bus) {
            printk(KERN_ERR PREFIX
                      "Bus %04x:%02x not present in PCI namespace\n",
                      root->id.segment, root->id.bus);
            result = -ENODEV;
            goto end;
      }

      /*
       * Attach ACPI-PCI Context
       * -----------------------
       * Thus binding the ACPI and PCI devices.
       */
      result = acpi_pci_bind_root(device, &root->id, root->bus);
      if (result)
            goto end;

      /*
       * PCI Routing Table
       * -----------------
       * Evaluate and parse _PRT, if exists.
       */
      status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
      if (ACPI_SUCCESS(status))
            result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
                                    root->id.bus);

      /*
       * Scan and bind all _ADR-Based Devices
       */
      list_for_each_entry(child, &device->children, node)
            acpi_pci_bridge_scan(child);

      end:
      if (result) {
            if (!list_empty(&root->node))
                  list_del(&root->node);
            kfree(root);
      }

      return result;
}

static int acpi_pci_root_start(struct acpi_device *device)
{
      struct acpi_pci_root *root;


      list_for_each_entry(root, &acpi_pci_roots, node) {
            if (root->device == device) {
                  pci_bus_add_devices(root->bus);
                  return 0;
            }
      }
      return -ENODEV;
}

static int acpi_pci_root_remove(struct acpi_device *device, int type)
{
      struct acpi_pci_root *root = NULL;


      if (!device || !acpi_driver_data(device))
            return -EINVAL;

      root = acpi_driver_data(device);

      kfree(root);

      return 0;
}

static int __init acpi_pci_root_init(void)
{

      if (acpi_pci_disabled)
            return 0;

      /* DEBUG:
         acpi_dbg_layer = ACPI_PCI_COMPONENT;
         acpi_dbg_level = 0xFFFFFFFF;
       */

      if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
            return -ENODEV;

      return 0;
}

subsys_initcall(acpi_pci_root_init);

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