Add the ability to reset the machine using the RESET_REG in ACPI's FADT table. Signed-off-by: Aaron Durbin <adurbin@xxxxxxxxxx> --- diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index d4336f1..c9906a5 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -21,7 +21,7 @@ obj-$(CONFIG_X86) += blacklist.o # # ACPI Core Subsystem (Interpreter) # -obj-y += osl.o utils.o \ +obj-y += osl.o utils.o reboot.o \ dispatcher/ events/ executer/ hardware/ \ namespace/ parser/ resources/ tables/ \ utilities/ diff --git a/drivers/acpi/reboot.c b/drivers/acpi/reboot.c new file mode 100644 index 0000000..4bb4d3e --- /dev/null +++ b/drivers/acpi/reboot.c @@ -0,0 +1,45 @@ + +#include <linux/pci.h> +#include <acpi/acpi.h> + +void acpi_reboot(void) +{ + struct acpi_generic_address *rr; + struct pci_bus *bus0; + u8 reset_value; + unsigned int devfn; + + rr = &acpi_gbl_FADT.reset_register; + + /* Is the reset register supported? */ + if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER) || + rr->bit_width != 8 || rr->bit_offset != 0) + 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_hw_low_level_write(8, reset_value, rr); + break; + } +} + diff --git a/include/acpi/reboot.h b/include/acpi/reboot.h new file mode 100644 index 0000000..1d8da79 --- /dev/null +++ b/include/acpi/reboot.h @@ -0,0 +1,10 @@ +#ifndef __ACPI_REBOOT_H +#define __ACPI_REBOOT_H + +#ifdef CONFIG_ACPI +extern void acpi_reboot(void); +#else +#define acpi_reboot() +#endif + +#endif - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html