arm: use a_ll/a_sc atomics when building for ARMv6T2

ARMv6 cores with support for Thumb2 can take advantage of the "ldrex"
and "strex" based implementations of a_ll and a_sc.

diff --git a/arch/arm/atomic_arch.h b/arch/arm/atomic_arch.h
index 5ff1be1b3dc7b0ed1f75f0a176c3275012283996..62458b45237ab46d59e436065a38dda77b4d918e 100644 (file)
--- a/arch/arm/atomic_arch.h
+++ b/arch/arm/atomic_arch.h
@@ -8,7 +8,7 @@ extern uintptr_t __attribute__((__visibility__("hidden")))
        __a_cas_ptr, __a_barrier_ptr;
 
 #if ((__ARM_ARCH_6__ || __ARM_ARCH_6K__ || __ARM_ARCH_6KZ__ || __ARM_ARCH_6ZK__) && !__thumb__) \
- || __ARM_ARCH_7A__ || __ARM_ARCH_7R__ ||  __ARM_ARCH >= 7
+ || __ARM_ARCH_6T2__ || __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
 
 #define a_ll a_ll
 static inline int a_ll(volatile int *p)