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>

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 40b0fcae4c78a71ac083119c96f6396e6e3bab07..4efbe598c817cfdeb58b8c41a4e67a33a08623c5 100644 (file)
--- 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 (file)
index 0000000..a6b662c
--- /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 8857f57e0b7804d0e931c8d05876913b09b052a0..0419184ce8867664164de63b2a232da985af718f 100644 (file)
--- 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