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author | Daniel R. Carvalho <odanrc@yahoo.com.br> | 2018-11-28 13:54:42 +0100 |
---|---|---|
committer | Daniel Carvalho <odanrc@yahoo.com.br> | 2018-12-04 10:34:26 +0000 |
commit | 174da8e2da6a896d2e97bc264f9c827a0f4c35ac (patch) | |
tree | b362adf7f2abf0cf309bf421ba0240c164791932 /src/mem/cache | |
parent | fc09f4a24e22988cb89650b1d5b1f3716cf5c893 (diff) | |
download | gem5-174da8e2da6a896d2e97bc264f9c827a0f4c35ac.tar.xz |
mem-cache: Add getter and setter to CacheBlk::whenReady
Add a getter and a setter function to access CacheBlk::whenReady
to encapsulate the variable and allow error checking. This error
checking consists on verifying that writes to a block after it
has been inserted follow a chronological order.
As a side effect, tickInserted retain its value until updated,
that is, it is not reset in invalidate().
Change-Id: Idc3c5a99c3f002ee9acc2424f00e554877fd3a69
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14715
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Diffstat (limited to 'src/mem/cache')
-rw-r--r-- | src/mem/cache/base.cc | 20 | ||||
-rw-r--r-- | src/mem/cache/cache_blk.hh | 37 |
2 files changed, 43 insertions, 14 deletions
diff --git a/src/mem/cache/base.cc b/src/mem/cache/base.cc index 244d7ce4e..bad24f7ee 100644 --- a/src/mem/cache/base.cc +++ b/src/mem/cache/base.cc @@ -900,10 +900,11 @@ BaseCache::calculateAccessLatency(const CacheBlk* blk, } // Check if the block to be accessed is available. If not, apply the - // access latency on top of block->whenReady. - if (blk->whenReady > curTick() && - ticksToCycles(blk->whenReady - curTick()) > lat) { - lat += ticksToCycles(blk->whenReady - curTick()); + // access latency on top of when the block is ready to be accessed. + const Tick when_ready = blk->getWhenReady(); + if (when_ready > curTick() && + ticksToCycles(when_ready - curTick()) > lat) { + lat += ticksToCycles(when_ready - curTick()); } } @@ -1024,8 +1025,8 @@ BaseCache::access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat, DPRINTF(Cache, "%s new state is %s\n", __func__, blk->print()); incHitCount(pkt); // populate the time when the block will be ready to access. - blk->whenReady = clockEdge(fillLatency) + pkt->headerDelay + - pkt->payloadDelay; + blk->setWhenReady(clockEdge(fillLatency) + pkt->headerDelay + + pkt->payloadDelay); return true; } else if (pkt->cmd == MemCmd::CleanEvict) { if (blk) { @@ -1081,8 +1082,8 @@ BaseCache::access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat, incHitCount(pkt); // populate the time when the block will be ready to access. - blk->whenReady = clockEdge(fillLatency) + pkt->headerDelay + - pkt->payloadDelay; + blk->setWhenReady(clockEdge(fillLatency) + pkt->headerDelay + + pkt->payloadDelay); // if this a write-through packet it will be sent to cache // below return !pkt->writeThrough(); @@ -1212,8 +1213,7 @@ BaseCache::handleFill(PacketPtr pkt, CacheBlk *blk, PacketList &writebacks, pkt->writeDataToBlock(blk->data, blkSize); } // We pay for fillLatency here. - blk->whenReady = clockEdge() + fillLatency * clockPeriod() + - pkt->payloadDelay; + blk->setWhenReady(clockEdge(fillLatency) + pkt->payloadDelay); return blk; } diff --git a/src/mem/cache/cache_blk.hh b/src/mem/cache/cache_blk.hh index d7530d656..9ace496ce 100644 --- a/src/mem/cache/cache_blk.hh +++ b/src/mem/cache/cache_blk.hh @@ -105,7 +105,10 @@ class CacheBlk : public ReplaceableEntry /** The current status of this block. @sa CacheBlockStatusBits */ State status; - /** Which curTick() will this block be accessible */ + /** + * Which curTick() will this block be accessible. Its value is only + * meaningful if the block is valid. + */ Tick whenReady; /** Number of references to this block since it was brought in. */ @@ -114,7 +117,10 @@ class CacheBlk : public ReplaceableEntry /** holds the source requestor ID for this block. */ int srcMasterId; - /** Tick on which the block was inserted in the cache. */ + /** + * Tick on which the block was inserted in the cache. Its value is only + * meaningful if the block is valid. + */ Tick tickInserted; protected: @@ -160,7 +166,7 @@ class CacheBlk : public ReplaceableEntry std::list<Lock> lockList; public: - CacheBlk() : data(nullptr) + CacheBlk() : data(nullptr), tickInserted(0) { invalidate(); } @@ -211,7 +217,6 @@ class CacheBlk : public ReplaceableEntry whenReady = MaxTick; refCount = 0; srcMasterId = Request::invldMasterId; - tickInserted = MaxTick; lockList.clear(); } @@ -261,6 +266,30 @@ class CacheBlk : public ReplaceableEntry } /** + * Get tick at which block's data will be available for access. + * + * @return Data ready tick. + */ + Tick getWhenReady() const + { + return whenReady; + } + + /** + * Set tick at which block's data will be available for access. The new + * tick must be chronologically sequential with respect to previous + * accesses. + * + * @param tick New data ready tick. + */ + void setWhenReady(const Tick tick) + { + assert((whenReady == MaxTick) || (tick >= whenReady)); + assert(tick >= tickInserted); + whenReady = tick; + } + + /** * Set member variables when a block insertion occurs. Resets reference * count to 1 (the insertion counts as a reference), and touch block if * it hadn't been touched previously. Sets the insertion tick to the |