rd: support XIP

Support direct_access XIP method with brd.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 8be67cd3fe01..b6d230b3209f 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -357,6 +357,16 @@ config BLK_DEV_RAM_SIZE
           The default value is 4096 kilobytes. Only change this if you know
           what you are doing.
 
+config BLK_DEV_XIP
+        bool "Support XIP filesystems on RAM block device"
+        depends on BLK_DEV_RAM
+        default n
+        help
+          Support XIP filesystems (such as ext2 with XIP support on) on
+          top of block ram device. This will slightly enlarge the kernel, and
+          will prevent RAM block device backing store memory from being
+          allocated from highmem (only a problem for highmem systems).
+
 config CDROM_PKTCDVD
         tristate "Packet writing on CD/DVD media"
         depends on !UML