This patch adds debugging/testing support to ERST. A misc device is
implemented to export raw ERST read/write/clear etc operations to user
space. With this patch, we can add ERST testing support to
linuxfirmwarekit ISO (linuxfirmwarekit.org) to verify the kernel
support and the firmware implementation.
Signed-off-by: Huang Ying
Acked-by: Randy Dunlap
Signed-off-by: Andi Kleen
Signed-off-by: Len Brown