+ * In cases where we want to make sure that a write has been flushed
+ * out of the write buffer before we proceed, for example when masking
+ * a device interrupt before re-enabling IRQs in CPSR, we can use this
+ * function, ixp2000_reg_wrb, which performs a write, a readback, and
+ * issues a dummy instruction dependent on the value of the readback
+ * (mov rX, rX) to make sure that the readback has completed before we
+ * continue.