+ /*
+ * Make sure the context image is complete before we submit it to HW.
+ *
+ * Ostensibly, writes (including the WCB) should be flushed prior to
+ * an uncached write such as our mmio register access, the empirical
+ * evidence (esp. on Braswell) suggests that the WC write into memory
+ * may not be visible to the HW prior to the completion of the UC
+ * register write and that we may begin execution from the context
+ * before its image is complete leading to invalid PD chasing.
+ */
+ wmb();