[ARM] 4567/1: Fix 'Oops - undefined instruction' when CONFIG_VFP=y on non VFP device
vfp_init() takes care of the condition when CONFIG_VFP=y but no real VFP
device exists. However, when this condition is true, a compiler might
misplace code lines in a way that will break this support. (To be more
specific - fmrx(FPSID) might be executed before vfp_testing_entry
assignment, which will end up with Oops - undefined instruction).
This patch adds a barrier() to guarantee the right execution ordering.
Signed-off-by: Assaf Hoffman
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 04ddab2..eea3f50 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -323,6 +323,7 @@
* we just need to read the VFPSID register.
*/
vfp_vector = vfp_testing_entry;
+ barrier();
vfpsid = fmrx(FPSID);
barrier();
vfp_vector = vfp_null_entry;
