cpu: Refactor memory system checks

CPUs need to test that the memory system is in the right mode in two
places, when the CPU is initialized (unless it's switched out) and on
a drainResume(). This led to some code duplication in the CPU
models. This changeset introduces the verifyMemoryMode() method which
is called by BaseCPU::init() if the CPU isn't switched out. The
individual CPU models are responsible for calling this method when
resuming from a drain as this code is CPU model specific.

4 files changed, 22 insertions, 20 deletions

diff --git a/src/cpu/simple/atomic.cc b/src/cpu/simple/atomic.cc
index 7255469a0..7a0778961 100644
--- a/src/cpu/simple/atomic.cc
+++ b/src/cpu/simple/atomic.cc
@@ -84,12 +84,6 @@ AtomicSimpleCPU::init()
 {
     BaseCPU::init();
 
-    if (!params()->switched_out &&
-        system->getMemoryMode() != Enums::atomic) {
-        fatal("The atomic CPU requires the memory system to be in "
-              "'atomic' mode.\n");
-    }
-
     // Initialise the ThreadContext's memory proxies
     tcBase()->initMemProxies(tcBase());
 
@@ -157,10 +151,7 @@ AtomicSimpleCPU::drainResume()
         return;
 
     DPRINTF(SimpleCPU, "Resume\n");
-    if (system->getMemoryMode() != Enums::atomic) {
-        fatal("The atomic CPU requires the memory system to be in "
-              "'atomic' mode.\n");
-    }
+    verifyMemoryMode();
 
     assert(!threadContexts.empty());
     if (threadContexts.size() > 1)
@@ -218,6 +209,14 @@ AtomicSimpleCPU::takeOverFrom(BaseCPU *oldCPU)
     data_write_req.setThreadContext(_cpuId, 0); // Add thread ID here too
 }
 
+void
+AtomicSimpleCPU::verifyMemoryMode() const
+{
+    if (system->getMemoryMode() != Enums::atomic) {
+        fatal("The atomic CPU requires the memory system to be in "
+              "'atomic' mode.\n");
+    }
+}
 
 void
 AtomicSimpleCPU::activateContext(ThreadID thread_num, Cycles delay)
diff --git a/src/cpu/simple/atomic.hh b/src/cpu/simple/atomic.hh
index 684125106..e3eafe8e0 100644
--- a/src/cpu/simple/atomic.hh
+++ b/src/cpu/simple/atomic.hh
@@ -164,6 +164,8 @@ class AtomicSimpleCPU : public BaseSimpleCPU
     void switchOut();
     void takeOverFrom(BaseCPU *oldCPU);
 
+    void verifyMemoryMode() const;
+
     virtual void activateContext(ThreadID thread_num, Cycles delay);
     virtual void suspendContext(ThreadID thread_num);
 
diff --git a/src/cpu/simple/timing.cc b/src/cpu/simple/timing.cc
index f6dc1fbf6..7423d082c 100644
--- a/src/cpu/simple/timing.cc
+++ b/src/cpu/simple/timing.cc
@@ -66,12 +66,6 @@ TimingSimpleCPU::init()
 {
     BaseCPU::init();
 
-    if (!params()->switched_out &&
-        system->getMemoryMode() != Enums::timing) {
-        fatal("The timing CPU requires the memory system to be in "
-              "'timing' mode.\n");
-    }
-
     // Initialise the ThreadContext's memory proxies
     tcBase()->initMemProxies(tcBase());
 
@@ -141,10 +135,7 @@ TimingSimpleCPU::drainResume()
         return;
 
     DPRINTF(SimpleCPU, "Resume\n");
-    if (system->getMemoryMode() != Enums::timing) {
-        fatal("The timing CPU requires the memory system to be in "
-              "'timing' mode.\n");
-    }
+    verifyMemoryMode();
 
     assert(!threadContexts.empty());
     if (threadContexts.size() > 1)
@@ -197,6 +188,14 @@ TimingSimpleCPU::takeOverFrom(BaseCPU *oldCPU)
     previousCycle = curCycle();
 }
 
+void
+TimingSimpleCPU::verifyMemoryMode() const
+{
+    if (system->getMemoryMode() != Enums::timing) {
+        fatal("The timing CPU requires the memory system to be in "
+              "'timing' mode.\n");
+    }
+}
 
 void
 TimingSimpleCPU::activateContext(ThreadID thread_num, Cycles delay)
diff --git a/src/cpu/simple/timing.hh b/src/cpu/simple/timing.hh
index af780265f..348129150 100644
--- a/src/cpu/simple/timing.hh
+++ b/src/cpu/simple/timing.hh
@@ -261,6 +261,8 @@ class TimingSimpleCPU : public BaseSimpleCPU
     void switchOut();
     void takeOverFrom(BaseCPU *oldCPU);
 
+    void verifyMemoryMode() const;
+
     virtual void activateContext(ThreadID thread_num, Cycles delay);
     virtual void suspendContext(ThreadID thread_num);