+/* FIXME: dcache_struct used to have a cache_has_stuff field that was
+ used to record whether the cache had been accessed. This was used
+ to invalidate the cache whenever caching was (re-)enabled (if the
+ cache was disabled and later re-enabled, it could contain stale
+ data). This was not needed because the cache is write through and
+ the code that enables, disables, and deletes memory region all
+ invalidate the cache.
+
+ This is overkill, since it also invalidates cache lines from
+ unrelated regions. One way this could be addressed by adding a
+ new function that takes an address and a length and invalidates
+ only those cache lines that match. */
+