ocf: add ocf submodule

This patch adds OCF as spdk submodule. By default ocf submodule is unused.
Type ./configure --with-ocf to enable ocf compliation.

Signed-off-by: Piotr Pelplinski <piotr.pelplinski@intel.com>
Change-Id: I7df228481c4228e6dbdea2ef0dc1d5513069ee08

Reviewed-on: https://review.gerrithub.io/c/444256
Reviewed-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "isa-l"]
 	path = isa-l
 	url = https://github.com/spdk/isa-l.git
+[submodule "ocf"]
+	path = ocf
+	url = https://github.com/Open-CAS/ocf.git

configure

@@ -69,6 +69,7 @@ function usage()
 	echo " ocf                       Required to build OCF module."
 	echo "                           If argument is directory, interpret it as root of OCF repo"
 	echo "                           If argument is file, interpret it as compiled OCF lib"
+	echo "                           If no argument is specified, OCF git submodule is used by default"
 	echo "                           example: /usr/src/ocf/"
 	echo " isal                      Enabled by default on x86 architecture. Can be built without though."
 	echo "                           No path required."
@@ -285,6 +286,10 @@ for i in "$@"; do
 		--without-ftl)
 			CONFIG[FTL]=n
 			;;
+		--with-ocf)
+			CONFIG[OCF]=y
+			CONFIG[OCF_PATH]=$(readlink -f "./ocf")
+			;;
 		--with-ocf=*)
 			CONFIG[OCF]=y
 			CONFIG[OCF_PATH]=$(readlink -f ${i#*=})
@@ -456,12 +461,6 @@ if [[ "${CONFIG[REDUCE]}" = "y" ]]; then
 fi
 
 if [[ "${CONFIG[OCF]}" = "y" ]]; then
-	if [ -z "${CONFIG[OCF_PATH]}" ]; then
-		echo "When OCF module is enabled, you must specify"
-		echo "the OCF directory or path to OCF library using --with-ocf=path"
-		exit 1
-	fi
-
 	# If OCF_PATH is a file, assume it is a library and use it to compile with
 	if [ -f ${CONFIG[OCF_PATH]} ]; then
 		CONFIG[CUSTOMOCF]=y

ocf

@@ -0,0 +1 @@
+Subproject commit 2074495935888683a94b3915f70630ecb2a25e0d