From d6bbccb60a656cc63a8ccb9800672aab411d723b Mon Sep 17 00:00:00 2001
From: Vishnu Ramadas <vramadas@wisc.edu>
Date: Mon, 9 Jan 2023 12:48:42 -0600
Subject: [PATCH] gpu-compute : Fix incorrect TLB stats when FunctionalTLB is
 used

When FunctionalTLB is used in SE mode, the stats tlbLatency and
tlbCycles report negative values. This patch fixes it by disabling the
updates that result in negative values when FunctionalTLB is set to true

Change-Id: I6962785fc1730b166b6d5b879e9c7618a8d6d4b3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/67202
Reviewed-by: Matt Sinclair <mattdsinclair.wisc@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matthew Poremba <matthew.poremba@amd.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---
 src/gpu-compute/compute_unit.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/gpu-compute/compute_unit.cc b/src/gpu-compute/compute_unit.cc
index 62cfbf94cf..06fe28f5b8 100644
--- a/src/gpu-compute/compute_unit.cc
+++ b/src/gpu-compute/compute_unit.cc
@@ -1078,7 +1078,9 @@ ComputeUnit::sendRequest(GPUDynInstPtr gpuDynInst, PortID index, PacketPtr pkt)
         fatal("pkt is not a read nor a write\n");
     }
 
-    stats.tlbCycles -= curTick();
+    if (!functionalTLB) {
+        stats.tlbCycles -= curTick();
+    }
     ++stats.tlbRequests;
 
     PortID tlbPort_index = perLaneTLB ? index : 0;