smp: only write rvbar if needed

Signed-off-by: Yureka <[email protected]>

Author: yuyuyureka

src/smp.c

@@ -140,7 +140,9 @@ static void smp_start_cpu(int index, int die, int cluster, int core, u64 impl, u
 
     sysop("dsb sy");
 
-    write64(impl, (u64)_vectors_start);
+    if ((read64(impl) & 0xfffffffff000) != (u64)_vectors_start) {
+        write64(impl, (u64)_vectors_start);
+    }
 
     cpu_start_base += die * PMGR_DIE_OFFSET;