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cpu-minor: fix store-release issuing

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Store with release flag are treated like store conditionals and are not
bufferable. Also they are only sent when the store buffer is empty to
satisfy the release semantics.

Change-Id: I253ec5ecd39901b14d0dc8efbc82cf7e4b07f08f
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27135
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
This commit is contained in:
Tiago Mück
2019-07-26 15:18:56 -05:00
parent 24dbb7ab93
commit 2b63ba5700
1 changed files with 12 additions and 2 deletions
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14
src/cpu/minor/lsq.cc
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@@ -1,5 +1,5 @@
/*
* Copyright (c) 2013-2014,2017-2018 ARM Limited
* Copyright (c) 2013-2014,2017-2018,2020 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
@@ -1029,10 +1029,11 @@ LSQ::tryToSendToTransfers(LSQRequestPtr request)
bool is_load = request->isLoad;
bool is_llsc = request->request->isLLSC();
bool is_release = request->request->isRelease();
bool is_swap = request->request->isSwap();
bool is_atomic = request->request->isAtomic();
bool bufferable = !(request->request->isStrictlyOrdered() ||
is_llsc || is_swap || is_atomic);
is_llsc || is_swap || is_atomic || is_release);
if (is_load) {
if (numStoresInTransfers != 0) {
@@ -1050,6 +1051,15 @@ LSQ::tryToSendToTransfers(LSQRequestPtr request)
}
}
// Process store conditionals or store release after all previous
// stores are completed
if (((!is_load && is_llsc) || is_release) &&
!storeBuffer.isDrained()) {
DPRINTF(MinorMem, "Memory access needs to wait for store buffer"
" to drain\n");
return;
}
/* Check if this is the head instruction (and so must be executable as
* its stream sequence number was checked above) for loads which must
* not be speculatively issued and stores which must be issued here */