PV-on-HVM: Define atomic_cmpxchg() for old Linux kernels.

Signed-off-by: KUWAMURA Shin'ya <kuwa@jp.fujitsu.com>

diff --git a/unmodified_drivers/linux-2.6/compat-include/xen/platform-compat.h b/unmodified_drivers/linux-2.6/compat-include/xen/platform-compat.h
index eceac2a4ff50f2ffe236725d50bd60619f297ce5..fd696704ee13d0809d6c09730f93e605ffdceb0d 100644 (file)
--- a/unmodified_drivers/linux-2.6/compat-include/xen/platform-compat.h
+++ b/unmodified_drivers/linux-2.6/compat-include/xen/platform-compat.h
@@ -157,4 +157,8 @@ typedef irqreturn_t (*irq_handler_t)(int, void *, struct pt_regs *);
 #define setup_xen_features xen_setup_features
 #endif
 
+#ifndef atomic_cmpxchg
+#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
+#endif
+
 #endif