aarch cycle_count - use a version of code from elsewhere

mirage · Mar 11, 2024 · c443b60 · c443b60
1 parent 20ed49f
commit c443b60
Showing 1 changed file with 2 additions and 3 deletions.
diff --git a/src/native/entropy_cpu_stubs.c b/src/native/entropy_cpu_stubs.c
@@ -111,12 +111,11 @@ static inline uint32_t read_virtual_count (void)
 #endif /* arm */
 
 #if defined (__aarch64__)
-#define	isb() __asm__ __volatile__("isb" : : : "memory")
+/* from https://github.com/ARM-software/synchronization-benchmarks/blob/master/benchmarks/lockhammer/include/perf_timer.h */
 static inline uint64_t read_virtual_count(void)
 {
   uint64_t c;
-  isb();
-  __asm__ __volatile__("mrs %0, cntvct_el0":"=r"(c));
+  __asm__ __volatile__("isb; mrs %0, cntvct_el0":"=r"(c));
   return c;
 }
 #endif /* aarch64 */