1 2 #include <linux/pci.h> 3 #include <linux/acpi.h> 4 #include <acpi/reboot.h> 5 6 void 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 /* ACPI reset register was only introduced with v2 of the FADT */ 19 20 if (acpi_gbl_FADT.header.revision < 2) 21 return; 22 23 /* Is the reset register supported? The spec says we should be 24 * checking the bit width and bit offset, but Windows ignores 25 * these fields */ 26 if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER)) 27 return; 28 29 reset_value = acpi_gbl_FADT.reset_value; 30 31 /* The reset register can only exist in I/O, Memory or PCI config space 32 * on a device on bus 0. */ 33 switch (rr->space_id) { 34 case ACPI_ADR_SPACE_PCI_CONFIG: 35 /* The reset register can only live on bus 0. */ 36 bus0 = pci_find_bus(0, 0); 37 if (!bus0) 38 return; 39 /* Form PCI device/function pair. */ 40 devfn = PCI_DEVFN((rr->address >> 32) & 0xffff, 41 (rr->address >> 16) & 0xffff); 42 printk(KERN_DEBUG "Resetting with ACPI PCI RESET_REG."); 43 /* Write the value that resets us. */ 44 pci_bus_write_config_byte(bus0, devfn, 45 (rr->address & 0xffff), reset_value); 46 break; 47 48 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 49 case ACPI_ADR_SPACE_SYSTEM_IO: 50 printk(KERN_DEBUG "ACPI MEMORY or I/O RESET_REG.\n"); 51 acpi_reset(); 52 break; 53 } 54 } 55