+#ifdef CONFIG_CPU_LOONGSON2F
+ /*
+ * Clear BTB (branch target buffer), forbid RAS (return address
+ * stack) to workaround the Out-of-order Issue in Loongson2F
+ * via its diagnostic register.
+ */
+ move k0, ra
+ jal 1f
+ nop
+1: jal 1f
+ nop
+1: jal 1f
+ nop
+1: jal 1f
+ nop
+1: move ra, k0
+ li k0, 3
+ mtc0 k0, $22
+#endif /* CONFIG_CPU_LOONGSON2F */