diff options
| author | Aaron Durbin <adurbin@google.com> | 2008-07-16 23:27:08 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2008-07-16 23:27:08 +0200 |
| commit | 4d3870431d17346c4fdd80e087b7d76f1b5941d5 (patch) | |
| tree | a8d3dcc5ab984ed7cbf67965372d58145bc90e9a | |
| parent | c83642d5123225a22cccd75adea6e97c245714cb (diff) | |
| download | lwn-4d3870431d17346c4fdd80e087b7d76f1b5941d5.tar.gz lwn-4d3870431d17346c4fdd80e087b7d76f1b5941d5.zip | |
Add the ability to reset the machine using the RESET_REG in ACPI's FADT table.
Signed-off-by: Aaron Durbin <adurbin@google.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | drivers/acpi/Makefile | 2 | ||||
| -rw-r--r-- | drivers/acpi/reboot.c | 50 | ||||
| -rw-r--r-- | include/acpi/reboot.h | 14 |
3 files changed, 59 insertions, 7 deletions
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 40b0fcae4c78..4efbe598c817 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 000000000000..a6b662c00b67 --- /dev/null +++ b/drivers/acpi/reboot.c @@ -0,0 +1,50 @@ + +#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; + + /* 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.\n"); + acpi_hw_low_level_write(8, reset_value, rr); + break; + } + /* Wait ten seconds */ + acpi_os_stall(10000000); +} diff --git a/include/acpi/reboot.h b/include/acpi/reboot.h index 8857f57e0b78..0419184ce886 100644 --- a/include/acpi/reboot.h +++ b/include/acpi/reboot.h @@ -1,9 +1,11 @@ +#ifndef __ACPI_REBOOT_H +#define __ACPI_REBOOT_H + +#ifdef CONFIG_ACPI +extern void acpi_reboot(void); +#else +static inline void acpi_reboot(void) { } +#endif -/* - * Dummy placeholder to make the EFI patches apply to the x86 tree. - * Andrew/Len, please just kill this file if you encounter it. - */ -#ifndef acpi_reboot -# define acpi_reboot() do { } while (0) #endif |