blob: a6c77e8b37bde54c266cae17d620c441a896e3b9 [file] [log] [blame]
Aaron Durbin4d387042008-07-16 23:27:08 +02001
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
Matthew Garrett95cf3e12011-03-11 16:12:20 -050018 /* ACPI reset register was only introduced with v2 of the FADT */
19
20 if (acpi_gbl_FADT.header.revision < 2)
21 return;
22
Matthew Garrett6734fe52011-03-11 16:12:19 -050023 /* 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))
Aaron Durbin4d387042008-07-16 23:27:08 +020027 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");
Lin Ming2ee62612008-12-16 16:40:31 +080051 acpi_reset();
Aaron Durbin4d387042008-07-16 23:27:08 +020052 break;
53 }
Aaron Durbin4d387042008-07-16 23:27:08 +020054}