mem: Make cache terminology easier to understand

This patch changes the name of a bunch of packet flags and MSHR member
functions and variables to make the coherency protocol easier to
understand. In addition the patch adds and updates lots of
descriptions, explicitly spelling out assumptions.

The following name changes are made:

* the packet memInhibit flag is renamed to cacheResponding

* the packet sharedAsserted flag is renamed to hasSharers

* the packet NeedsExclusive attribute is renamed to NeedsWritable

* the packet isSupplyExclusive is renamed responderHadWritable

* the MSHR pendingDirty is renamed to pendingModified

The cache states, Modified, Owned, Exclusive, Shared are also called
out in the cache and MSHR code to make it easier to understand.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/mem/cache/mshr_queue.hh b/src/mem/cache/mshr_queue.hh
index a2ad6d020..45aa1c15f 100644
--- a/src/mem/cache/mshr_queue.hh
+++ b/src/mem/cache/mshr_queue.hh
@@ -188,10 +188,10 @@ class MSHRQueue : public Drainable
      * readyList or deallocates the MSHR if it does not expect a response.
      *
      * @param mshr The MSHR to mark in service.
-     * @param pending_dirty_resp Whether we expect a dirty response
-     *                           from another cache
+     * @param pending_modified_resp Whether we expect a modified response
+     *                              from another cache
      */
-    void markInService(MSHR *mshr, bool pending_dirty_resp);
+    void markInService(MSHR *mshr, bool pending_modified_resp);
 
     /**
      * Mark an in service entry as pending, used to resend a request.