selinux: move ibpkeys code under CONFIG_SECURITY_INFINIBAND.

Move cache based pkey sid retrieval code which was added
with commit "409dcf31" under CONFIG_SECURITY_INFINIBAND.
As its going to alloc a new cache which impacts
low RAM devices which was enabled by default.

Suggested-by: Paul Moore <[e-mail]>
Signed-off-by: Ravi Kumar Siddojigari <[e-mail]>
[PM: checkpatch.pl cleanups, fixed capitalization in the description]
Signed-off-by: Paul Moore <[e-mail]>

security/selinux/Makefile

···
 obj-$(CONFIG_SECURITY_SELINUX) := selinux.o
 
 selinux-y := avc.o hooks.o selinuxfs.o netlink.o nlmsgtab.o netif.o \
-	     netnode.o netport.o ibpkey.o \
+	     netnode.o netport.o \
 	     ss/ebitmap.o ss/hashtab.o ss/symtab.o ss/sidtab.o ss/avtab.o \
 	     ss/policydb.o ss/services.o ss/conditional.o ss/mls.o ss/status.o
 
 selinux-$(CONFIG_SECURITY_NETWORK_XFRM) += xfrm.o
 
 selinux-$(CONFIG_NETLABEL) += netlabel.o
+
+selinux-$(CONFIG_SECURITY_INFINIBAND) += ibpkey.o
 
 ccflags-y := -I$(srctree)/security/selinux -I$(srctree)/security/selinux/include
 

security/selinux/include/ibpkey.h

···
 #ifndef _SELINUX_IB_PKEY_H
 #define _SELINUX_IB_PKEY_H
 
+#ifdef CONFIG_SECURITY_INFINIBAND
 void sel_ib_pkey_flush(void);
-
 int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey, u32 *sid);
+#else
+static inline void sel_ib_pkey_flush(void)
+{
+	return;
+}
+static inline int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey, u32 *sid)
+{
+	*sid = SECINITSID_UNLABELED;
+	return 0;
+}
+#endif
 
 #endif