1 files changed, 17 insertions, 0 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index e79de2bd12cd..a0cd086df16b 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -654,3 +654,20 @@ config DEFERRED_STRUCT_PAGE_INIT
           when kswapd starts. This has a potential performance impact on
           processes running early in the lifetime of the systemm until kswapd
           finishes the initialisation.
+
+config ZONE_DEVICE
+        bool "Device memory (pmem, etc...) hotplug support" if EXPERT
+        default !ZONE_DMA
+        depends on !ZONE_DMA
+        depends on MEMORY_HOTPLUG
+        depends on MEMORY_HOTREMOVE
+        depends on X86_64 #arch_add_memory() comprehends device memory
+
+        help
+          Device memory hotplug support allows for establishing pmem,
+          or other device driver discovered memory regions, in the
+          memmap. This allows pfn_to_page() lookups of otherwise
+          "device-physical" addresses which is needed for using a DAX
+          mapping in an O_DIRECT operation, among other things.
+
+          If FS_DAX is enabled, then say Y.