Use DMB only on ARMv7

[urcu.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index d1d43e645c3366e457c5d34d8475a21af5cc80e2..daa967a738a057a61dc69b5e93c9c047c4b71524 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -21,7 +21,6 @@ m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 AC_REQUIRE_AUX_FILE([tap-driver.sh])
 
 AH_TEMPLATE([CONFIG_RCU_SMP], [Enable SMP support. With SMP support enabled, uniprocessors are also supported. With SMP support disabled, UP systems work fine, but the behavior of SMP systems is undefined.])
-AH_TEMPLATE([CONFIG_RCU_ARM_HAVE_DMB], [Use the dmb instruction if available for use on ARM.])
 AH_TEMPLATE([CONFIG_RCU_TLS], [TLS provided by the compiler.])
 AH_TEMPLATE([CONFIG_RCU_HAVE_CLOCK_GETTIME], [clock_gettime() is detected.])
 AH_TEMPLATE([CONFIG_RCU_FORCE_SYS_MEMBARRIER], [Require the operating system to support the membarrier system call for default and bulletproof flavors.])
@@ -124,24 +123,6 @@ AS_IF([test "$host_cpu" = "armv7l"],[
        AM_CFLAGS="$AM_CFLAGS -mcpu=cortex-a9 -mtune=cortex-a9 -O1"
 ])
 
-# ARM-specific checks
-AS_CASE([$host_cpu], [arm*], [
-       AC_MSG_CHECKING([for dmb instruction])
-       AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
-                               int main()
-                               {
-                                       asm volatile("dmb":::"memory");
-                                       return 0;
-                               }
-               ]])
-       ],[
-               AC_MSG_RESULT([yes])
-               AC_DEFINE([CONFIG_RCU_ARM_HAVE_DMB], [1])
-       ],[
-               AC_MSG_RESULT([no])
-       ])
-])
-
 # Search for clock_gettime
 AC_SEARCH_LIBS([clock_gettime], [rt], [
        AC_DEFINE([CONFIG_RCU_HAVE_CLOCK_GETTIME], [1])