#include <linux/pci.h>
  #include <linux/acpi.h>
  #include <acpi/reboot.h>
  
  void acpi_reboot(void)
  {
  	struct acpi_generic_address *rr;
  	struct pci_bus *bus0;
  	u8 reset_value;
  	unsigned int devfn;
  
  	if (acpi_disabled)
  		return;
  
  	rr = &acpi_gbl_FADT.reset_register;

  	/* ACPI reset register was only introduced with v2 of the FADT */
  
  	if (acpi_gbl_FADT.header.revision < 2)
  		return;

  	/* Is the reset register supported? The spec says we should be
  	 * checking the bit width and bit offset, but Windows ignores
  	 * these fields */

  	if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER))
  		return;

  
  	reset_value = acpi_gbl_FADT.reset_value;
  
  	/* The reset register can only exist in I/O, Memory or PCI config space
  	 * on a device on bus 0. */
  	switch (rr->space_id) {
  	case ACPI_ADR_SPACE_PCI_CONFIG:
  		/* The reset register can only live on bus 0. */
  		bus0 = pci_find_bus(0, 0);
  		if (!bus0)
  			return;
  		/* Form PCI device/function pair. */
  		devfn = PCI_DEVFN((rr->address >> 32) & 0xffff,
  				  (rr->address >> 16) & 0xffff);
  		printk(KERN_DEBUG "Resetting with ACPI PCI RESET_REG.");
  		/* Write the value that resets us. */
  		pci_bus_write_config_byte(bus0, devfn,
  				(rr->address & 0xffff), reset_value);
  		break;
  
  	case ACPI_ADR_SPACE_SYSTEM_MEMORY:
  	case ACPI_ADR_SPACE_SYSTEM_IO:
  		printk(KERN_DEBUG "ACPI MEMORY or I/O RESET_REG.
  ");

  		acpi_reset();

  		break;
  	}

  }