pstore: Allow the user to explicitly choose a backend

pstore only allows one backend to be registered at present, but the
system may provide several. Add a parameter to allow the user to choose
which backend will be used rather than just relying on load order.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/pstore b/Documentation/ABI/testing/pstore
index ddf451ee2a08..ff1df4e3b059 100644
--- a/Documentation/ABI/testing/pstore
+++ b/Documentation/ABI/testing/pstore
@@ -39,3 +39,9 @@ Description:	Generic interface to platform dependent persistent storage.
                 multiple) files based on the record size of the underlying
                 persistent storage until at least this amount is reached.
                 Default is 10 Kbytes.
+
+                Pstore only supports one backend at a time. If multiple
+                backends are available, the preferred backend may be
+                set by passing the pstore.backend= argument to the kernel at
+                boot time.
+