mem-ruby: Use check_on_cache_probe to protect locked lines from eviction

This change uses check_on_cache_probe statement to check if the cacheline
subject to eviction is locked in MESI Two Level. Other protocols should
be updated accordingly.

Signed-off-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Change-Id: Idcdbc8ee528eb5e4e2f8d56a268a3a92eadd95b1
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/16809
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

diff --git a/src/mem/protocol/MESI_Two_Level-L1cache.sm b/src/mem/protocol/MESI_Two_Level-L1cache.sm
index 87684ce10bb28e093b5ede8a25795e076b900cec..51d3f621c0d7ffa1b04ae54ab2b29f95413babe1 100644 (file)
--- a/src/mem/protocol/MESI_Two_Level-L1cache.sm
+++ b/src/mem/protocol/MESI_Two_Level-L1cache.sm
@@ -472,9 +472,14 @@ machine(MachineType:L1Cache, "MESI Directory L1 Cache CMP")
                       L1Icache_entry, TBEs[in_msg.LineAddress]);
             } else {
               // No room in the L1, so we need to make room in the L1
-              trigger(Event:L1_Replacement, L1Icache.cacheProbe(in_msg.LineAddress),
-                      getL1ICacheEntry(L1Icache.cacheProbe(in_msg.LineAddress)),
-                      TBEs[L1Icache.cacheProbe(in_msg.LineAddress)]);
+
+              // Check if the line we want to evict is not locked
+              Addr addr := L1Icache.cacheProbe(in_msg.LineAddress);
+              check_on_cache_probe(mandatoryQueue_in, addr);
+
+              trigger(Event:L1_Replacement, addr,
+                      getL1ICacheEntry(addr),
+                      TBEs[addr]);
             }
           }
         } else {
@@ -502,9 +507,14 @@ machine(MachineType:L1Cache, "MESI Directory L1 Cache CMP")
                       L1Dcache_entry, TBEs[in_msg.LineAddress]);
             } else {
               // No room in the L1, so we need to make room in the L1
-              trigger(Event:L1_Replacement, L1Dcache.cacheProbe(in_msg.LineAddress),
-                      getL1DCacheEntry(L1Dcache.cacheProbe(in_msg.LineAddress)),
-                      TBEs[L1Dcache.cacheProbe(in_msg.LineAddress)]);
+
+              // Check if the line we want to evict is not locked
+              Addr addr := L1Dcache.cacheProbe(in_msg.LineAddress);
+              check_on_cache_probe(mandatoryQueue_in, addr);
+
+              trigger(Event:L1_Replacement, addr,
+                      getL1DCacheEntry(addr),
+                      TBEs[addr]);
             }
           }
         }