Add deadman timer (only ten cycles!) based on time between interruptable points.

3 files changed, 5 insertions, 1 deletions

diff --git a/Plan b/Plan
index 9e102f2..13f50b4 100644
--- a/Plan
+++ b/Plan
@@ -1,6 +1,5 @@
 vim: set sw=8 noet :
 
-        * Deadman timer
         * D-side cache
                 * Store forwarding
                 * Cache consistency between I and D side
diff --git a/uarch/core.cpp b/uarch/core.cpp
index 503e286..ce58df2 100644
--- a/uarch/core.cpp
+++ b/uarch/core.cpp
@@ -364,6 +364,9 @@ bail_out:
         if (interrupt || oldctlregs != ctlregs)
             if (!restarttr.has_value())
                 restarttr = infra::pt::toplevel();
+        cycles_since_progress = 0;
+    } else {
+        assert(++cycles_since_progress < 10);
     }
 
     if (restarttr.has_value()) {
diff --git a/uarch/core.h b/uarch/core.h
index b8473e6..ebfd388 100644
--- a/uarch/core.h
+++ b/uarch/core.h
@@ -78,6 +78,8 @@ struct indir_stage : public infra::sim {
 struct exec_stage : public infra::sim {
     core &c;
 
+    unsigned int cycles_since_progress = 0;
+
     unsigned int gen = 0;
 
     unsigned int stores_sent = 0;