mem-cache: Insert on block allocation

When a block is being replaced in an allocation, if successfull,
the block will be inserted. Therefore we move the insertion
functionality to allocateBlock().

allocateBlock's signature has been modified to allow this
modification.

Change-Id: I60d17a83ff4f3021fdc976378868ccde6c7507bc
Reviewed-on: https://gem5-review.googlesource.com/10812
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

diff --git a/src/mem/cache/base.cc b/src/mem/cache/base.cc
index a5ad07d6c83ed4f7634990cfa937c89d69cc9034..e43c3d9200d969c882e0266691d68d99fc82f87f 100644 (file)
--- a/src/mem/cache/base.cc
+++ b/src/mem/cache/base.cc
@@ -970,13 +970,12 @@ BaseCache::access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat,
 
         if (!blk) {
             // need to do a replacement
-            blk = allocateBlock(pkt->getAddr(), pkt->isSecure(), writebacks);
+            blk = allocateBlock(pkt, writebacks);
             if (!blk) {
                 // no replaceable block available: give up, fwd to next level.
                 incMissCount(pkt);
                 return false;
             }
-            tags->insertBlock(pkt, blk);
 
             blk->status |= (BlkValid | BlkReadable);
         }
@@ -1028,15 +1027,13 @@ BaseCache::access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat,
                 return false;
             } else {
                 // a writeback that misses needs to allocate a new block
-                blk = allocateBlock(pkt->getAddr(), pkt->isSecure(),
-                                    writebacks);
+                blk = allocateBlock(pkt, writebacks);
                 if (!blk) {
                     // no replaceable block available: give up, fwd to
                     // next level.
                     incMissCount(pkt);
                     return false;
                 }
-                tags->insertBlock(pkt, blk);
 
                 blk->status |= (BlkValid | BlkReadable);
             }
@@ -1124,7 +1121,7 @@ BaseCache::handleFill(PacketPtr pkt, CacheBlk *blk, PacketList &writebacks,
 
         // need to do a replacement if allocating, otherwise we stick
         // with the temporary storage
-        blk = allocate ? allocateBlock(addr, is_secure, writebacks) : nullptr;
+        blk = allocate ? allocateBlock(pkt, writebacks) : nullptr;
 
         if (!blk) {
             // No replaceable block or a mostly exclusive
@@ -1135,8 +1132,6 @@ BaseCache::handleFill(PacketPtr pkt, CacheBlk *blk, PacketList &writebacks,
             tempBlock->insert(addr, is_secure);
             DPRINTF(Cache, "using temp block for %#llx (%s)\n", addr,
                     is_secure ? "s" : "ns");
-        } else {
-            tags->insertBlock(pkt, blk);
         }
 
         // we should never be overwriting a valid block
@@ -1205,8 +1200,14 @@ BaseCache::handleFill(PacketPtr pkt, CacheBlk *blk, PacketList &writebacks,
 }
 
 CacheBlk*
-BaseCache::allocateBlock(Addr addr, bool is_secure, PacketList &writebacks)
+BaseCache::allocateBlock(const PacketPtr pkt, PacketList &writebacks)
 {
+    // Get address
+    const Addr addr = pkt->getAddr();
+
+    // Get secure bit
+    const bool is_secure = pkt->isSecure();
+
     // Find replacement victim
     std::vector<CacheBlk*> evict_blks;
     CacheBlk *victim = tags->findVictim(addr, is_secure, evict_blks);
@@ -1257,6 +1258,9 @@ BaseCache::allocateBlock(Addr addr, bool is_secure, PacketList &writebacks)
         }
     }
 
+    // Insert new block at victimized entry
+    tags->insertBlock(pkt, victim);
+
     return victim;
 }
 

diff --git a/src/mem/cache/base.hh b/src/mem/cache/base.hh
index 6600aeba6bfccdf8a8e67ee57fe02b979cbd55ff..4ba256b95dbef1a521abd5a50da54bbe040a9ba8 100644 (file)
--- a/src/mem/cache/base.hh
+++ b/src/mem/cache/base.hh
@@ -659,14 +659,14 @@ class BaseCache : public MemObject
      *
      * Find a victim block and if necessary prepare writebacks for any
      * existing data. May return nullptr if there are no replaceable
-     * blocks.
+     * blocks. If a replaceable block is found, it inserts the new block in
+     * its place. The new block, however, is not set as valid yet.
      *
-     * @param addr Physical address of the new block
-     * @param is_secure Set if the block should be secure
+     * @param pkt Packet holding the address to update
      * @param writebacks A list of writeback packets for the evicted blocks
      * @return the allocated block
      */
-    CacheBlk *allocateBlock(Addr addr, bool is_secure, PacketList &writebacks);
+    CacheBlk *allocateBlock(const PacketPtr pkt, PacketList &writebacks);
     /**
      * Evict a cache block.
      *