3 files changed, 32 insertions, 2 deletions

diff --git a/src/mem/cache/mshr.hh b/src/mem/cache/mshr.hh
index 56b81b6b2..b94dfb9c5 100644
--- a/src/mem/cache/mshr.hh
+++ b/src/mem/cache/mshr.hh
@@ -514,6 +514,16 @@ class MSHR : public QueueEntry, public Printable
     bool trySatisfyFunctional(PacketPtr pkt);
 
     /**
+     * Adds a delay relative to the current tick to the current MSHR
+     * @param delay_ticks the desired delay in ticks
+     */
+    void delay(Tick delay_ticks)
+    {
+        assert(readyTime <= curTick());
+        readyTime = curTick() + delay_ticks;
+    }
+
+    /**
      * Prints the contents of this MSHR for debugging.
      */
     void print(std::ostream &os,
diff --git a/src/mem/cache/mshr_queue.cc b/src/mem/cache/mshr_queue.cc
index e44a21954..f4b80540c 100644
--- a/src/mem/cache/mshr_queue.cc
+++ b/src/mem/cache/mshr_queue.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2013, 2015-2016 ARM Limited
+ * Copyright (c) 2012-2013, 2015-2016, 2018 ARM Limited
  * All rights reserved.
  *
  * The license below extends only to copyright in the software and shall
@@ -85,6 +85,17 @@ MSHRQueue::moveToFront(MSHR *mshr)
 }
 
 void
+MSHRQueue::delay(MSHR *mshr, Tick delay_ticks)
+{
+    mshr->delay(delay_ticks);
+    auto it = std::find_if(mshr->readyIter, readyList.end(),
+                            [mshr] (const MSHR* _mshr) {
+                                return mshr->readyTime >= _mshr->readyTime;
+                            });
+    readyList.splice(it, readyList, mshr->readyIter);
+}
+
+void
 MSHRQueue::markInService(MSHR *mshr, bool pending_modified_resp)
 {
     mshr->markInService(pending_modified_resp);
diff --git a/src/mem/cache/mshr_queue.hh b/src/mem/cache/mshr_queue.hh
index 1b960a5a2..1e4eaeb51 100644
--- a/src/mem/cache/mshr_queue.hh
+++ b/src/mem/cache/mshr_queue.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2013, 2015-2016 ARM Limited
+ * Copyright (c) 2012-2013, 2015-2016, 2018 ARM Limited
  * All rights reserved.
  *
  * The license below extends only to copyright in the software and shall
@@ -107,6 +107,15 @@ class MSHRQueue : public Queue<MSHR>
     void moveToFront(MSHR *mshr);
 
     /**
+     * Adds a delay to the provided MSHR and moves MSHRs that will be
+     * ready earlier than this entry to the top of the list
+     *
+     * @param mshr that needs to be delayed
+     * @param delay_ticks ticks of the desired delay
+     */
+    void delay(MSHR *mshr, Tick delay_ticks);
+
+    /**
      * Mark the given MSHR as in service. This removes the MSHR from the
      * readyList or deallocates the MSHR if it does not expect a response.
      *