1 files changed, 27 insertions, 1 deletions

diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index e0700bf4893a..5ef624fe3934 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -23,12 +23,38 @@ config DEV_DAX
 config DEV_DAX_PMEM
         tristate "PMEM DAX: direct access to persistent memory"
         depends on LIBNVDIMM && NVDIMM_DAX && DEV_DAX
+        depends on m # until we can kill DEV_DAX_PMEM_COMPAT
         default DEV_DAX
         help
           Support raw access to persistent memory.  Note that this
           driver consumes memory ranges allocated and exported by the
           libnvdimm sub-system.
 
-          Say Y if unsure
+          Say M if unsure
+
+config DEV_DAX_KMEM
+        tristate "KMEM DAX: volatile-use of persistent memory"
+        default DEV_DAX
+        depends on DEV_DAX
+        depends on MEMORY_HOTPLUG # for add_memory() and friends
+        help
+          Support access to persistent memory as if it were RAM.  This
+          allows easier use of persistent memory by unmodified
+          applications.
+
+          To use this feature, a DAX device must be unbound from the
+          device_dax driver (PMEM DAX) and bound to this kmem driver
+          on each boot.
+
+          Say N if unsure.
+
+config DEV_DAX_PMEM_COMPAT
+        tristate "PMEM DAX: support the deprecated /sys/class/dax interface"
+        depends on DEV_DAX_PMEM
+        default DEV_DAX_PMEM
+        help
+          Older versions of the libdaxctl library expect to find all
+          device-dax instances under /sys/class/dax. If libdaxctl in
+          your distribution is older than v58 say M, otherwise say N.
 
 endif