Initial support for CPU switching. New SamplingCPU object encompasses a set

of CPUs that get switched round-robin (though currently we're only shooting for
two CPUs and one switch event, and even that doesn't quite work yet).  Registration
of ExecContexts with System/Process object factored out so we can create two CPUs
but only register one of them at a time.  Also worked at making behavior and naming
in System and Process objects more consistent.

arch/alpha/ev5.cc:
    Rename ipr_init to initIPRs and get rid of unused mem arg.
arch/alpha/fake_syscall.cc:
    Process:numCpus is now a function (not a data member).
base/remote_gdb.hh:
    Support for ExecContext switching.
cpu/base_cpu.cc:
cpu/base_cpu.hh:
cpu/exec_context.cc:
cpu/exec_context.hh:
cpu/simple_cpu/simple_cpu.hh:
    Support for ExecContext switching.
    Renamed contexts array to execContexts to be consistent with Process.
    CPU ID now auto-assigned by system object.
cpu/simple_cpu/simple_cpu.cc:
    Support for ExecContext switching.
    Renamed contexts array to execContexts to be consistent with Process.
    CPU ID now auto-assigned by system object.
    Cleaned up MP full-system initialization a bit.
dev/alpha_console.cc:
    Renamed xcvec array to execContexts to be consistent with Process.
kern/tru64/tru64_system.cc:
kern/tru64/tru64_system.hh:
    Support for ExecContext switching.
    CPU ID now auto-assigned by system object.
sim/prog.cc:
sim/prog.hh:
    Support for ExecContext switching.
    Process:numCpus is now a function (not a data member).
sim/system.cc:
sim/system.hh:
    Support for ExecContext switching.
    Renamed xcvec array to execContexts to be consistent with Process.

--HG--
extra : convert_revision : 79649cffad5bf3e83de8df44236941907926d791

1 files changed, 58 insertions, 6 deletions

diff --git a/cpu/base_cpu.cc b/cpu/base_cpu.cc
index 90e090d5e..74d2ceada 100644
--- a/cpu/base_cpu.cc
+++ b/cpu/base_cpu.cc
@@ -52,8 +52,8 @@ BaseCPU::BaseCPU(const string &_name, int _number_of_threads,
                  Counter max_insts_all_threads,
                  Counter max_loads_any_thread,
                  Counter max_loads_all_threads,
-                 System *_system, int num, Tick freq)
-    : SimObject(_name), number(num), frequency(freq),
+                 System *_system, Tick freq)
+    : SimObject(_name), frequency(freq),
       number_of_threads(_number_of_threads), system(_system)
 #else
 BaseCPU::BaseCPU(const string &_name, int _number_of_threads,
@@ -120,27 +120,73 @@ BaseCPU::BaseCPU(const string &_name, int _number_of_threads,
                 max_loads_all_threads, *counter);
     }
 
-
 #ifdef FULL_SYSTEM
     memset(interrupts, 0, sizeof(interrupts));
     intstatus = 0;
 #endif
 }
 
+
 void
 BaseCPU::regStats()
 {
-    int size = contexts.size();
+    int size = execContexts.size();
     if (size > 1) {
         for (int i = 0; i < size; ++i) {
             stringstream namestr;
             ccprintf(namestr, "%s.ctx%d", name(), i);
-            contexts[i]->regStats(namestr.str());
+            execContexts[i]->regStats(namestr.str());
         }
     } else if (size == 1)
-        contexts[0]->regStats(name());
+        execContexts[0]->regStats(name());
+}
+
+
+void
+BaseCPU::registerExecContexts()
+{
+    for (int i = 0; i < execContexts.size(); ++i) {
+        ExecContext *xc = execContexts[i];
+        int cpu_id;
+
+#ifdef FULL_SYSTEM
+        cpu_id = system->registerExecContext(xc);
+#else
+        cpu_id = xc->process->registerExecContext(xc);
+#endif
+
+        xc->cpu_id = cpu_id;
+    }
+}
+
+
+void
+BaseCPU::switchOut()
+{
+    // default: do nothing
 }
 
+void
+BaseCPU::takeOverFrom(BaseCPU *oldCPU)
+{
+    assert(execContexts.size() == oldCPU->execContexts.size());
+
+    for (int i = 0; i < execContexts.size(); ++i) {
+        ExecContext *newXC = execContexts[i];
+        ExecContext *oldXC = oldCPU->execContexts[i];
+
+        newXC->takeOverFrom(oldXC);
+        assert(newXC->cpu_id == oldXC->cpu_id);
+#ifdef FULL_SYSTEM
+        system->replaceExecContext(newXC->cpu_id, newXC);
+#else
+        assert(newXC->process == oldXC->process);
+        newXC->process->replaceExecContext(newXC->cpu_id, newXC);
+#endif
+    }
+}
+
+
 #ifdef FULL_SYSTEM
 void
 BaseCPU::post_interrupt(int int_num, int index)
@@ -185,4 +231,10 @@ BaseCPU::clear_interrupts()
 
 #endif // FULL_SYSTEM
 
+//
+// This declaration is not needed now that SamplingCPU provides a
+// BaseCPUBuilder object.
+//
+#if 0
 DEFINE_SIM_OBJECT_CLASS_NAME("BaseCPU", BaseCPU)
+#endif