xf86atomic: require CAS support in libatomic_ops

Since AO_compare_and_swap_full() is used by libdrm, AO_REQUIRE_CAS
must be defined before including <atomic_ops.h> so that we are sure
that CAS support will be provided. This is necessary to make sure that
the AO_compare_and_swap_full() function will be provided on all
architectures, including the ones that don't have built-in CAS support
such as SPARCv8.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Acked-by: Eric Engestrom <eric.engestrom@intel.com>

diff --git a/xf86atomic.h b/xf86atomic.h
index 2d733bd..efa47a7 100644 (file)
--- a/xf86atomic.h
+++ b/xf86atomic.h
@@ -54,6 +54,7 @@ typedef struct {
 #endif
 
 #if HAVE_LIB_ATOMIC_OPS
+#define AO_REQUIRE_CAS
 #include <atomic_ops.h>
 
 #define HAS_ATOMIC_OPS 1