MEM: Make CLREX a first class request operation and clear locks in caches when it in received

src/arch/arm/isa/insts/misc.isa

@@ -669,7 +669,7 @@ let {{
     exec_output += PredOpExecute.subst(setendIop)
 
     clrexCode = '''
-        unsigned memAccessFlags = ArmISA::TLB::Clrex|3|Request::LLSC;
+        unsigned memAccessFlags = Request::CLREX|3|Request::LLSC;
         fault = xc->read(0, (uint32_t&)Mem, memAccessFlags);
     '''
     clrexIop = InstObjParams("clrex", "Clrex","PredOp",

src/arch/arm/isa/templates/misc.isa

@@ -367,7 +367,7 @@ def template ClrexInitiateAcc {{
         if (%(predicate_test)s)
         {
             if (fault == NoFault) {
-                unsigned memAccessFlags = ArmISA::TLB::Clrex|3|Request::LLSC;
+                unsigned memAccessFlags = Request::CLREX|3|Request::LLSC;
                 fault = xc->read(0, (uint32_t&)Mem, memAccessFlags);
             }
         } else {

src/arch/arm/tlb.cc

@@ -358,9 +358,10 @@ TLB::translateFs(RequestPtr req, ThreadContext *tc, Mode mode,
     // If this is a clrex instruction, provide a PA of 0 with no fault
     // This will force the monitor to set the tracked address to 0
     // a bit of a hack but this effectively clrears this processors monitor
-    if (flags & Clrex){
+    if (flags & Request::CLREX){
        req->setPaddr(0);
        req->setFlags(Request::UNCACHEABLE);
+       req->setFlags(Request::CLREX);
        return NoFault;
     }
     if ((req->isInstFetch() && (!sctlr.i)) ||

src/arch/arm/tlb.hh

@@ -78,8 +78,7 @@ class TLB : public BaseTLB
         // Because zero otherwise looks like a valid setting and may be used
         // accidentally, this bit must be non-zero to show it was used on
         // purpose.
-        MustBeOne = 0x20,
-        Clrex = 0x40
+        MustBeOne = 0x20
     };
   protected:
     typedef std::multimap<Addr, int> PageTable;

src/mem/cache/cache_impl.hh

@@ -273,12 +273,14 @@ bool
 Cache<TagStore>::access(PacketPtr pkt, BlkType *&blk,
                         int &lat, PacketList &writebacks)
 {
-    int id = pkt->req->hasContextId() ? pkt->req->contextId() : -1;
-    blk = tags->accessBlock(pkt->getAddr(), lat, id);
-
-    if (pkt->req->isUncacheable())  {
-        if (blk != NULL) {
-            tags->invalidateBlk(blk);
+    if (pkt->req->isUncacheable()) {
+        if (pkt->req->isClrex()) {
+            tags->clearLocks();
+        } else {
+           blk = tags->findBlock(pkt->getAddr());
+           if (blk != NULL) {
+               tags->invalidateBlk(blk);
+           }
         }
 
         blk = NULL;
@@ -286,6 +288,8 @@ Cache<TagStore>::access(PacketPtr pkt, BlkType *&blk,
         return false;
     }
 
+    int id = pkt->req->hasContextId() ? pkt->req->contextId() : -1;
+    blk = tags->accessBlock(pkt->getAddr(), lat, id);
 
     DPRINTF(Cache, "%s%s %x %s\n", pkt->cmdString(),
             pkt->req->isInstFetch() ? " (ifetch)" : "",
@@ -410,11 +414,13 @@ Cache<TagStore>::timingAccess(PacketPtr pkt)
     }
 
     if (pkt->req->isUncacheable()) {
-        int lat = hitLatency;
-        int id = pkt->req->hasContextId() ? pkt->req->contextId() : -1;
-        BlkType *blk = tags->accessBlock(pkt->getAddr(), lat, id);
-        if (blk != NULL) {
-            tags->invalidateBlk(blk);
+        if (pkt->req->isClrex()) {
+            tags->clearLocks();
+        } else {
+            BlkType *blk = tags->findBlock(pkt->getAddr());
+            if (blk != NULL) {
+                tags->invalidateBlk(blk);
+            }
         }
 
         // writes go in write buffer, reads use MSHR

src/mem/cache/tags/base.hh

@@ -140,6 +140,12 @@ class BaseTags
      * exits.
      */
     virtual void cleanupRefs() {}
+
+    /**
+     *iterated through all blocks and clear all locks
+     *Needed to clear all lock tracking at once
+     */
+    virtual void clearLocks() {}
 };
 
 class BaseTagsCallback : public Callback

src/mem/cache/tags/fa_lru.cc

@@ -286,3 +286,11 @@ FALRU::check()
     }
     return true;
 }
+
+void
+FALRU::clearLocks()
+{
+    for (int i = 0; i < numBlocks; i++){
+        blks[i].clearLoadLocks();
+    }
+}

src/mem/cache/tags/fa_lru.hh

@@ -280,6 +280,12 @@ public:
     {
         return (tag);
     }
+
+    /**
+     *iterated through all blocks and clear all locks
+     *Needed to clear all lock tracking at once
+     */
+    virtual void clearLocks();
 };
 
 #endif // __MEM_CACHE_TAGS_FA_LRU_HH__

src/mem/cache/tags/iic.cc

@@ -631,6 +631,14 @@ IIC::invalidateBlk(IIC::BlkType *tag_ptr)
     }
 }
 
+void
+IIC::clearLocks()
+{
+    for (int i = 0; i < numTags; i++){
+        tagStore[i].clearLoadLocks();
+    }
+}
+
 void
 IIC::cleanupRefs()
 {

src/mem/cache/tags/iic.hh

@@ -439,6 +439,11 @@ class IIC : public BaseTags
     IICTag* findVictim(Addr addr, PacketList &writebacks);
 
     void insertBlock(Addr addr, BlkType *blk, int context_src);
+    /**
+     *iterated through all blocks and clear all locks
+     *Needed to clear all lock tracking at once
+     */
+    virtual void clearLocks();
 
     /**
      * Called at end of simulation to complete average block reference stats.
@@ -497,6 +502,7 @@ private:
      * @param data_ptr The data block to free.
      */
     void freeDataBlock(unsigned long data_ptr);
+
 };
 #endif // __IIC_HH__
 

src/mem/cache/tags/lru.cc

@@ -216,6 +216,14 @@ LRU::invalidateBlk(BlkType *blk)
     }
 }
 
+void
+LRU::clearLocks()
+{
+    for (int i = 0; i < numBlocks; i++){
+        blks[i].clearLoadLocks();
+    }
+}
+
 void
 LRU::cleanupRefs()
 {

src/mem/cache/tags/lru.hh

@@ -224,6 +224,11 @@ public:
     {
         return hitLatency;
     }
+    /**
+     *iterated through all blocks and clear all locks
+     *Needed to clear all lock tracking at once
+     */
+    virtual void clearLocks();
 
     /**
      * Called at end of simulation to complete average block reference stats.

src/mem/request.hh

@@ -71,6 +71,8 @@ class Request : public FastAlloc
     static const FlagsType UNCACHEABLE                 = 0x00001000;
     /** This request is to a memory mapped register. */
     static const FlagsType MMAPED_IPR                  = 0x00002000;
+    /** This request is a clear exclusive. */
+    static const FlagsType CLREX                       = 0x00004000;
 
     /** The request should ignore unaligned access faults */
     static const FlagsType NO_ALIGN_FAULT              = 0x00020000;
@@ -456,6 +458,7 @@ class Request : public FastAlloc
     bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
     bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
     bool isMmapedIpr() const { return _flags.isSet(MMAPED_IPR); }
+    bool isClrex() const { return _flags.isSet(CLREX); }
 
     bool
     isMisaligned() const