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authorAaron Durbin <adurbin@google.com>2008-07-16 17:27:08 -0400
committerAndi Kleen <andi@basil.nowhere.org>2008-07-16 17:27:08 -0400
commit4d3870431d17346c4fdd80e087b7d76f1b5941d5 (patch)
treea8d3dcc5ab984ed7cbf67965372d58145bc90e9a /drivers
parentc83642d5123225a22cccd75adea6e97c245714cb (diff)
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/Makefile2
-rw-r--r--drivers/acpi/reboot.c50
2 files changed, 51 insertions, 1 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
21# 21#
22# ACPI Core Subsystem (Interpreter) 22# ACPI Core Subsystem (Interpreter)
23# 23#
24obj-y += osl.o utils.o \ 24obj-y += osl.o utils.o reboot.o\
25 dispatcher/ events/ executer/ hardware/ \ 25 dispatcher/ events/ executer/ hardware/ \
26 namespace/ parser/ resources/ tables/ \ 26 namespace/ parser/ resources/ tables/ \
27 utilities/ 27 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 @@
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_hw_low_level_write(8, reset_value, rr);
46 break;
47 }
48 /* Wait ten seconds */
49 acpi_os_stall(10000000);
50}