linux_dsm_epyc7002/drivers/acpi/reboot.c
Aaron Durbin 4d3870431d 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>
2008-07-16 23:27:08 +02:00

51 lines
1.3 KiB
C

#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);
}