mem-cache: Return evictions along with victims

For both sector and compressed caches multiple blocks may need
to be evicted in order to make room for a new block.

For example, when replacing a sector, all the blocks in this
sector must be evicted. A replacement, however, does not always
need to evict multiple blocks, as it is in the case of an
insertion of a block whose sector is already present in the cache
(i.e., its corresponding entry in the sector had not been brought
in yet, so it was invalid).

This patch creates the cache framework for that to happen.

Change-Id: I77bedf69637cf899fef4d9432eb6da8529ea398b
Reviewed-on: https://gem5-review.googlesource.com/10142
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/src/mem/cache/tags/base.hh b/src/mem/cache/tags/base.hh
index 167364ff1..27771982a 100644
--- a/src/mem/cache/tags/base.hh
+++ b/src/mem/cache/tags/base.hh
@@ -262,12 +262,20 @@ class BaseTags : public ClockedObject
     }
 
     /**
-     * Find replacement victim based on address.
+     * Find replacement victim based on address. If the address requires
+     * blocks to be evicted, their locations are listed for eviction. If a
+     * conventional cache is being used, the list only contains the victim.
+     * However, if using sector or compressed caches, the victim is one of
+     * the blocks to be evicted, but its location is the only one that will
+     * be assigned to the newly allocated block associated to this address.
+     * @sa insertBlock
      *
      * @param addr Address to find a victim for.
+     * @param evict_blks Cache blocks to be evicted.
      * @return Cache block to be replaced.
      */
-    virtual CacheBlk* findVictim(Addr addr) = 0;
+    virtual CacheBlk* findVictim(Addr addr, std::vector<CacheBlk*>& evict_blks)
+                                                                     const = 0;
 
     virtual CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) = 0;