Merge pull request #985 from riscv-software-src/trigger_hit

Implement mcontrol.hit bit

2 files changed, 18 insertions, 11 deletions

diff --git a/riscv/triggers.cc b/riscv/triggers.cc
index 69888bf..4d16a58 100644
--- a/riscv/triggers.cc
+++ b/riscv/triggers.cc
@@ -1,11 +1,12 @@
+#include "debug_defines.h"
 #include "processor.h"
 #include "triggers.h"
 
 namespace triggers {
 
 mcontrol_t::mcontrol_t() :
-  type(2), maskmax(0), select(false), timing(false), chain_bit(false),
-  match(MATCH_EQUAL), m(false), h(false), s(false), u(false),
+  select(false), timing(false), chain_bit(false),
+  match(MATCH_EQUAL), m(false), s(false), u(false),
   execute_bit(false), store_bit(false), load_bit(false)
 {
 }
@@ -13,16 +14,16 @@ mcontrol_t::mcontrol_t() :
 reg_t mcontrol_t::tdata1_read(const processor_t * const proc) const noexcept {
   reg_t v = 0;
   auto xlen = proc->get_xlen();
-  v = set_field(v, MCONTROL_TYPE(xlen), type);
+  v = set_field(v, MCONTROL_TYPE(xlen), MCONTROL_TYPE_MATCH);
   v = set_field(v, MCONTROL_DMODE(xlen), dmode);
-  v = set_field(v, MCONTROL_MASKMAX(xlen), maskmax);
+  v = set_field(v, MCONTROL_MASKMAX(xlen), 0);
+  v = set_field(v, CSR_MCONTROL_HIT, hit);
   v = set_field(v, MCONTROL_SELECT, select);
   v = set_field(v, MCONTROL_TIMING, timing);
   v = set_field(v, MCONTROL_ACTION, action);
   v = set_field(v, MCONTROL_CHAIN, chain_bit);
   v = set_field(v, MCONTROL_MATCH, match);
   v = set_field(v, MCONTROL_M, m);
-  v = set_field(v, MCONTROL_H, h);
   v = set_field(v, MCONTROL_S, s);
   v = set_field(v, MCONTROL_U, u);
   v = set_field(v, MCONTROL_EXECUTE, execute_bit);
@@ -37,6 +38,7 @@ bool mcontrol_t::tdata1_write(processor_t * const proc, const reg_t val) noexcep
   }
   auto xlen = proc->get_xlen();
   dmode = get_field(val, MCONTROL_DMODE(xlen));
+  hit = get_field(val, CSR_MCONTROL_HIT);
   select = get_field(val, MCONTROL_SELECT);
   timing = get_field(val, MCONTROL_TIMING);
   action = (triggers::action_t) get_field(val, MCONTROL_ACTION);
@@ -56,7 +58,6 @@ bool mcontrol_t::tdata1_write(processor_t * const proc, const reg_t val) noexcep
       break;
   }
   m = get_field(val, MCONTROL_M);
-  h = get_field(val, MCONTROL_H);
   s = get_field(val, MCONTROL_S);
   u = get_field(val, MCONTROL_U);
   execute_bit = get_field(val, MCONTROL_EXECUTE);
@@ -133,6 +134,9 @@ match_result_t mcontrol_t::memory_access_match(processor_t * const proc, operati
   }
 
   if (simple_match(xlen, value)) {
+    /* This is OK because this function is only called if the trigger was not
+     * inhibited by the previous trigger in the chain. */
+    hit = true;
     if (timing)
       return MATCH_FIRE_AFTER;
     else
@@ -167,6 +171,12 @@ match_result_t module_t::memory_access_match(action_t * const action, operation_
       continue;
     }
 
+    /* Note: We call memory_access_match for each trigger in a chain as long as
+     * the triggers are matching. This results in "temperature coding" so that
+     * `hit` is set on each of the consecutive triggers that matched, even if the
+     * entire chain did not match. This is allowed by the spec, because the final
+     * trigger in the chain will never get `hit` set unless the entire chain
+     * matches. */
     match_result_t result = triggers[i]->memory_access_match(proc, operation, address, data);
     if (result != MATCH_NONE && !triggers[i]->chain()) {
       *action = triggers[i]->action;
diff --git a/riscv/triggers.h b/riscv/triggers.h
index ad294c8..19fa437 100644
--- a/riscv/triggers.h
+++ b/riscv/triggers.h
@@ -58,11 +58,12 @@ public:
 public:
   bool dmode;
   action_t action;
+  bool hit;
 
   virtual ~trigger_t() {};
 
 protected:
-  trigger_t() : dmode(false), action(ACTION_DEBUG_EXCEPTION) {};
+  trigger_t() : dmode(false), action(ACTION_DEBUG_EXCEPTION), hit(false) {};
 };
 
 class mcontrol_t : public trigger_t {
@@ -96,21 +97,17 @@ private:
   bool simple_match(unsigned xlen, reg_t value) const;
 
 public:
-  uint8_t type;
-  uint8_t maskmax;
   bool select;
   bool timing;
   bool chain_bit;
   match_t match;
   bool m;
-  bool h;
   bool s;
   bool u;
   bool execute_bit;
   bool store_bit;
   bool load_bit;
   reg_t tdata2;
-
 };
 
 class module_t {