UBI: Wire-up fastmap

Make fastmap known to Kconfig, UBI Makefile and MAINTAINERS.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

2 files changed, 22 insertions, 0 deletions

diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig
index 271a842f8c39..36663af56d89 100644
--- a/drivers/mtd/ubi/Kconfig
+++ b/drivers/mtd/ubi/Kconfig
@@ -56,6 +56,27 @@ config MTD_UBI_BEB_LIMIT
 
           Leave the default value if unsure.
 
+config MTD_UBI_FASTMAP
+        bool "UBI Fastmap (Experimental feature)"
+        default n
+        help
+           Important: this feature is experimental so far and the on-flash
+           format for fastmap may change in the next kernel versions
+
+           Fastmap is a mechanism which allows attaching an UBI device
+           in nearly constant time. Instead of scanning the whole MTD device it
+           only has to locate a checkpoint (called fastmap) on the device.
+           The on-flash fastmap contains all information needed to attach
+           the device. Using fastmap makes only sense on large devices where
+           attaching by scanning takes long. UBI will not automatically install
+           a fastmap on old images, but you can set the UBI module parameter
+           fm_autoconvert to 1 if you want so. Please note that fastmap-enabled
+           images are still usable with UBI implementations without
+           fastmap support. On typical flash devices the whole fastmap fits
+           into one PEB. UBI will reserve PEBs to hold two fastmaps.
+
+           If in doubt, say "N".
+
 config MTD_UBI_GLUEBI
         tristate "MTD devices emulation driver (gluebi)"
         help
diff --git a/drivers/mtd/ubi/Makefile b/drivers/mtd/ubi/Makefile
index a0803ac74712..b46b0c978581 100644
--- a/drivers/mtd/ubi/Makefile
+++ b/drivers/mtd/ubi/Makefile
@@ -2,5 +2,6 @@ obj-$(CONFIG_MTD_UBI) += ubi.o
 
 ubi-y += vtbl.o vmt.o upd.o build.o cdev.o kapi.o eba.o io.o wl.o attach.o
 ubi-y += misc.o debug.o
+ubi-$(CONFIG_MTD_UBI_FASTMAP) += fastmap.o
 
 obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o