O3,ARM: fix some problems with drain/switchout functionality and add Drain DPRINTFs

This patch fixes some problems with the drain/switchout functionality
for the O3 cpu and for the ARM ISA and adds some useful debug print
statements.

This is an incremental fix as there are still a few bugs/mem leaks with the
switchout code. Particularly when switching from an O3CPU to a
TimingSimpleCPU. However, when switching from O3 to O3 cores with the ARM ISA
I haven't encountered any more assertion failures; now the kernel will
typically panic inside of simulation.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/arch/arm/table_walker.hh b/src/arch/arm/table_walker.hh
index db6b01cd4..1b95182c8 100644
--- a/src/arch/arm/table_walker.hh
+++ b/src/arch/arm/table_walker.hh
@@ -364,6 +364,9 @@ class TableWalker : public MemObject
     /** Port to issue translation requests from */
     SnoopingDmaPort port;
 
+    /** If we're draining keep the drain event around until we're drained */
+    Event *drainEvent;
+
     /** TLB that is initiating these table walks */
     TLB *tlb;
 
@@ -389,6 +392,8 @@ class TableWalker : public MemObject
         return dynamic_cast<const Params *>(_params);
     }
 
+    /** Checks if all state is cleared and if so, completes drain */
+    void completeDrain();
     virtual unsigned int drain(Event *de);
     virtual void resume();
     virtual MasterPort& getMasterPort(const std::string &if_name,