Mem: Use range operations in bus in preparation for striping

This patch transitions the bus to use the AddrRange operations instead
of directly accessing the start and end. The change facilitates the
move to a more elaborate AddrRange class that also supports address
striping in the bus by specifying interleaving bits in the ranges.

Two new functions are added to the AddrRange to determine if two
ranges intersect, and if one is a subset of another. The bus
propagation of address ranges is also tweaked such that an update is
only propagated if the bus received information from all the
downstream slave modules. This avoids the iteration and need for the
cycle-breaking scheme that was previously used.

1 files changed, 2 insertions, 6 deletions

diff --git a/src/mem/addr_mapper.cc b/src/mem/addr_mapper.cc
index 53e8277cc..28fc85245 100644
--- a/src/mem/addr_mapper.cc
+++ b/src/mem/addr_mapper.cc
@@ -272,14 +272,10 @@ RangeAddrMapper::getAddrRanges() const
         AddrRange range = *r;
 
         for (int j = 0; j < originalRanges.size(); ++j) {
-            if ((range.start < originalRanges[j].start &&
-                 range.end >= originalRanges[j].start) ||
-                (range.start < originalRanges[j].end &&
-                 range.end >= originalRanges[j].end))
+            if (range.intersects(originalRanges[j]))
                 fatal("Cannot remap range that intersects the original"
                       " ranges but are not a subset.\n");
-            if (range.start >= originalRanges[j].start &&
-                range.end <= originalRanges[j].end) {
+            if (range.isSubset(originalRanges[j])) {
                 // range is a subset
                 Addr offset = range.start - originalRanges[j].start;
                 range.start -= offset;