mem: Add a FromCache packet attribute

This patch adds a FromCache attribute to the packet, and updates a
number of the existing request commands to reflect that the request
originates from a cache. The attribute simplifies checking if a
requests came from a cache or not, and this is used by both the cache
and snoop filter in follow-on patches.

Change-Id: Ib0a7a080bbe4d6036ddd84b46fd45bc7eb41cd8f
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Steve Reinhardt <stever@gmail.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/src/mem/cache/cache.cc b/src/mem/cache/cache.cc
index 15c2b7a54..c3f289123 100644
--- a/src/mem/cache/cache.cc
+++ b/src/mem/cache/cache.cc
@@ -191,14 +191,8 @@ Cache::satisfyCpuSideRequest(PacketPtr pkt, CacheBlk *blk,
         assert(pkt->hasRespData());
         pkt->setDataFromBlock(blk->data, blkSize);
 
-        // determine if this read is from a (coherent) cache, or not
-        // by looking at the command type; we could potentially add a
-        // packet attribute such as 'FromCache' to make this check a
-        // bit cleaner
-        if (pkt->cmd == MemCmd::ReadExReq ||
-            pkt->cmd == MemCmd::ReadSharedReq ||
-            pkt->cmd == MemCmd::ReadCleanReq ||
-            pkt->cmd == MemCmd::SCUpgradeFailReq) {
+        // determine if this read is from a (coherent) cache or not
+        if (pkt->fromCache()) {
             assert(pkt->getSize() == blkSize);
             // special handling for coherent block requests from
             // upper-level caches