From 174da8e2da6a896d2e97bc264f9c827a0f4c35ac Mon Sep 17 00:00:00 2001
From: "Daniel R. Carvalho" <odanrc@yahoo.com.br>
Date: Wed, 28 Nov 2018 13:54:42 +0100
Subject: 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>
---
 src/mem/cache/cache_blk.hh | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

(limited to 'src/mem/cache/cache_blk.hh')

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();
     }
 
@@ -260,6 +265,30 @@ class CacheBlk : public ReplaceableEntry
         status |= BlkSecure;
     }
 
+    /**
+     * 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
-- 
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