LXR linux/drivers/acpi/reboot.c

   1
   2#include <linux/pci.h>
   3#include <linux/acpi.h>
   4#include <acpi/reboot.h>
   5
   6void acpi_reboot(void)
   7{
   8        struct acpi_generic_address *rr;
   9        struct pci_bus *bus0;
  10        u8 reset_value;
  11        unsigned int devfn;
  12
  13        if (acpi_disabled)
  14                return;
  15
  16        rr = &acpi_gbl_FADT.reset_register;
  17
  18        /* Is the reset register supported? */
  19        if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER) ||
  20            rr->bit_width != 8 || rr->bit_offset != 0)
  21                return;
  22
  23        reset_value = acpi_gbl_FADT.reset_value;
  24
  25        /* The reset register can only exist in I/O, Memory or PCI config space
  26         * on a device on bus 0. */
  27        switch (rr->space_id) {
  28        case ACPI_ADR_SPACE_PCI_CONFIG:
  29                /* The reset register can only live on bus 0. */
  30                bus0 = pci_find_bus(0, 0);
  31                if (!bus0)
  32                        return;
  33                /* Form PCI device/function pair. */
  34                devfn = PCI_DEVFN((rr->address >> 32) & 0xffff,
  35                                  (rr->address >> 16) & 0xffff);
  36                printk(KERN_DEBUG "Resetting with ACPI PCI RESET_REG.");
  37                /* Write the value that resets us. */
  38                pci_bus_write_config_byte(bus0, devfn,
  39                                (rr->address & 0xffff), reset_value);
  40                break;
  41
  42        case ACPI_ADR_SPACE_SYSTEM_MEMORY:
  43        case ACPI_ADR_SPACE_SYSTEM_IO:
  44                printk(KERN_DEBUG "ACPI MEMORY or I/O RESET_REG.\n");
  45                acpi_reset();
  46                break;
  47        }
  48        /* Wait ten seconds */
  49        acpi_os_stall(10000000);
  50}
  51