efivars: Allow disabling use as a pstore backend

Add a new option, CONFIG_EFI_VARS_PSTORE, which can be set to N to
avoid using efivars as a backend to pstore, as some users may want to
compile out the code completely.

Set the default to Y to maintain backwards compatability, since this
feature has always been enabled until now.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 9b00072a020f..898023d8e486 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -53,6 +53,15 @@ config EFI_VARS
           Subsequent efibootmgr releases may be found at:
           <http://linux.dell.com/efibootmgr>
 
+config EFI_VARS_PSTORE
+        bool "Register efivars backend for pstore"
+        depends on EFI_VARS && PSTORE
+        default y
+        help
+          Say Y here to enable use efivars as a backend to pstore. This
+          will allow writing console messages, crash dumps, or anything
+          else supported by pstore to EFI variables.
+
 config EFI_PCDP
         bool "Console device selection via EFI PCDP or HCDP table"
         depends on ACPI && EFI && IA64