X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=configure.ac;h=3e1b50141efc49fc5ba6d316b16c7453ba207db3;hp=69ce396ef07956e98d0480103a879fc8ed382305;hb=5e626e0ea1c03a239cca95bf8c3fc9d4fbebde12;hpb=6aca01252647cb7f035ae731d2ce3cf1b02ab501

diff --git a/configure.ac b/configure.ac
index 69ce396..3e1b501 100644
--- a/configure.ac
+++ b/configure.ac
@@ -20,6 +20,7 @@ AH_TEMPLATE([CONFIG_RCU_HAVE_FENCE], [Defined when on a system that has memory f
 AH_TEMPLATE([CONFIG_RCU_HAVE_FUTEX], [Defined when on a system with futex support.])
 AH_TEMPLATE([CONFIG_RCU_COMPAT_ARCH], [Compatibility mode for i386 which lacks
 cmpxchg instruction.])
+AH_TEMPLATE([CONFIG_ARM_HAVE_DMB], [Use the dmb instruction is available for use on ARM.])
 
 # Checks for programs.
 AC_PROG_CC
@@ -56,6 +57,25 @@ case $host_cpu in
 	*) ARCHTYPE="unknown";;
 esac
 
+if test "x$ARCHTYPE" = "xarm" ; then
+AC_MSG_CHECKING([checking for dmb instruction])
+AC_TRY_COMPILE(
+[
+],
+[
+asm volatile("dmb":::"memory");
+],
+[
+	AC_MSG_RESULT([yes])
+	AC_DEFINE([CONFIG_ARM_HAVE_DMB], [1])
+]
+,
+[
+	AC_MSG_RESULT([no])
+]
+)
+fi
+
 UATOMICSRC=urcu/uatomic_arch_$ARCHTYPE.h
 ARCHSRC=urcu/arch_$ARCHTYPE.h
 if test "x$ARCHTYPE" != xx86 -a "x$ARCHTYPE" != xppc; then