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authorNikos Nikoleris <nikos.nikoleris@arm.com>2016-11-21 10:12:25 +0000
committerNikos Nikoleris <nikos.nikoleris@arm.com>2018-06-19 08:05:30 +0000
commit699ef82eba4ffe4ba49645968d2969b56599b617 (patch)
treeefb7e2e1af54c8a814467fdd54ab7cb1b4836424 /src
parent05c4c2b566ce351ab217b2bd7035562aa7a76570 (diff)
downloadgem5-699ef82eba4ffe4ba49645968d2969b56599b617.tar.xz
mem-cache: Fix support for secure blocks in the FALRU cache
Fully associative caches use an unordered map to enable efficient lookups of existing blocks. Previously this map was indexed using the tag of the block. Security extentions allow secure and non secure versions of a block with the same tag to co-exist in the cache. This patch amends the block map to allow correct lookups for FALRU caches. Change-Id: Iccf07464deab56d1d270bae14bb3b154047e3556 Reviewed-on: https://gem5-review.googlesource.com/11309 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Diffstat (limited to 'src')
-rw-r--r--src/mem/cache/tags/fa_lru.cc28
-rw-r--r--src/mem/cache/tags/fa_lru.hh22
2 files changed, 22 insertions, 28 deletions
diff --git a/src/mem/cache/tags/fa_lru.cc b/src/mem/cache/tags/fa_lru.cc
index bcf785e27..60998e254 100644
--- a/src/mem/cache/tags/fa_lru.cc
+++ b/src/mem/cache/tags/fa_lru.cc
@@ -107,16 +107,6 @@ FALRU::regStats()
cacheTracking.regStats(name());
}
-FALRUBlk *
-FALRU::hashLookup(Addr addr) const
-{
- tagIterator iter = tagHash.find(addr);
- if (iter != tagHash.end()) {
- return (*iter).second;
- }
- return nullptr;
-}
-
void
FALRU::invalidate(CacheBlk *blk)
{
@@ -129,7 +119,7 @@ FALRU::invalidate(CacheBlk *blk)
moveToTail((FALRUBlk*)blk);
// Erase block entry in the hash table
- tagHash.erase(blk->tag);
+ tagHash.erase(std::make_pair(blk->tag, blk->isSecure()));
}
CacheBlk*
@@ -145,7 +135,7 @@ FALRU::accessBlock(Addr addr, bool is_secure, Cycles &lat,
CachesMask mask = 0;
FALRUBlk* blk = static_cast<FALRUBlk*>(findBlock(addr, is_secure));
- if (blk != nullptr) {
+ if (blk && blk->isValid()) {
// If a cache hit
lat = accessLatency;
// Check if the block to be accessed is available. If not,
@@ -175,15 +165,19 @@ FALRU::accessBlock(Addr addr, bool is_secure, Cycles &lat,
CacheBlk*
FALRU::findBlock(Addr addr, bool is_secure) const
{
+ FALRUBlk* blk = nullptr;
+
Addr tag = extractTag(addr);
- FALRUBlk* blk = hashLookup(tag);
+ auto iter = tagHash.find(std::make_pair(tag, is_secure));
+ if (iter != tagHash.end()) {
+ blk = (*iter).second;
+ }
if (blk && blk->isValid()) {
assert(blk->tag == tag);
assert(blk->isSecure() == is_secure);
- } else {
- blk = nullptr;
}
+
return blk;
}
@@ -225,7 +219,7 @@ FALRU::insertBlock(const PacketPtr pkt, CacheBlk *blk)
moveToHead(falruBlk);
// Insert new block in the hash table
- tagHash[falruBlk->tag] = falruBlk;
+ tagHash[std::make_pair(blk->tag, blk->isSecure())] = falruBlk;
}
void
@@ -406,7 +400,7 @@ FALRU::CacheTracking::recordAccess(FALRUBlk *blk)
}
// Record stats for the actual cache too
- if (blk) {
+ if (blk && blk->isValid()) {
hits[numTrackedCaches]++;
} else {
misses[numTrackedCaches]++;
diff --git a/src/mem/cache/tags/fa_lru.hh b/src/mem/cache/tags/fa_lru.hh
index 35413c253..876219b00 100644
--- a/src/mem/cache/tags/fa_lru.hh
+++ b/src/mem/cache/tags/fa_lru.hh
@@ -111,19 +111,19 @@ class FALRU : public BaseTags
FALRUBlk *tail;
/** Hash table type mapping addresses to cache block pointers. */
- typedef std::unordered_map<Addr, FALRUBlk *, std::hash<Addr> > hash_t;
- /** Iterator into the address hash table. */
- typedef hash_t::const_iterator tagIterator;
+ struct PairHash
+ {
+ template <class T1, class T2>
+ std::size_t operator()(const std::pair<T1, T2> &p) const
+ {
+ return std::hash<T1>()(p.first) ^ std::hash<T2>()(p.second);
+ }
+ };
+ typedef std::pair<Addr, bool> TagHashKey;
+ typedef std::unordered_map<TagHashKey, FALRUBlk *, PairHash> TagHash;
/** The address hash table. */
- hash_t tagHash;
-
- /**
- * Find the cache block for the given address.
- * @param addr The address to find.
- * @return The cache block of the address, if any.
- */
- FALRUBlk * hashLookup(Addr addr) const;
+ TagHash tagHash;
/**
* Move a cache block to the MRU position.