From 7884d5296dc694100c622470970b18a1dd5c3f71 Mon Sep 17 00:00:00 2001
From: Giacomo Travaglini <giacomo.travaglini@arm.com>
Date: Tue, 7 Jul 2020 15:30:22 +0100
Subject: [PATCH] arch-arm: Move breakpoint/watchpoint check out of the TLB

The breakpoint, watchpoint, vector catch and software step checks
have been moved from the TLB to the SelfDebug class.

This is cleaningup the TLB model which is simply asking the SelfDebug
class if there is a pending debug fault

Change-Id: I1724896b24e4728b32a6b46c5cd51cc6ef279fd7
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/31079
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---
 src/arch/arm/self_debug.cc | 25 +++++++++++++++++++++++++
 src/arch/arm/self_debug.hh |  8 +++++++-
 src/arch/arm/tlb.cc        | 21 +++------------------
 3 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/src/arch/arm/self_debug.cc b/src/arch/arm/self_debug.cc
index 9a60aab68..96c78226c 100644
--- a/src/arch/arm/self_debug.cc
+++ b/src/arch/arm/self_debug.cc
@@ -44,6 +44,31 @@
 using namespace ArmISA;
 using namespace std;
 
+Fault
+SelfDebug::testDebug(ThreadContext *tc, const RequestPtr &req,
+                     BaseTLB::Mode mode)
+{
+    Fault fault = NoFault;
+
+    if (mode == BaseTLB::Execute) {
+        const bool d_step = softStep->advanceSS(tc);
+        if (!d_step) {
+            fault = testVectorCatch(tc, req->getVaddr(), nullptr);
+            if (fault == NoFault)
+                fault = testBreakPoints(tc, req->getVaddr());
+        }
+    } else if (!req->isCacheMaintenance() ||
+             (req->isCacheInvalidate() && !req->isCacheClean())) {
+        bool md = mode == BaseTLB::Write ? true: false;
+        fault = testWatchPoints(tc, req->getVaddr(), md,
+                                req->isAtomic(),
+                                req->getSize(),
+                                req->isCacheMaintenance());
+    }
+
+    return fault;
+}
+
 Fault
 SelfDebug::testBreakPoints(ThreadContext *tc, Addr vaddr)
 {
diff --git a/src/arch/arm/self_debug.hh b/src/arch/arm/self_debug.hh
index 67654d2d7..121ddde44 100644
--- a/src/arch/arm/self_debug.hh
+++ b/src/arch/arm/self_debug.hh
@@ -44,6 +44,7 @@
 #include "arch/arm/system.hh"
 #include "arch/arm/types.hh"
 #include "arch/arm/utility.hh"
+#include "arch/generic/tlb.hh"
 #include "cpu/thread_context.hh"
 
 class ThreadContext;
@@ -322,14 +323,19 @@ class SelfDebug
         delete vcExcpt;
     }
 
+    Fault testDebug(ThreadContext *tc, const RequestPtr &req,
+                    BaseTLB::Mode mode);
+
+  protected:
     Fault testBreakPoints(ThreadContext *tc, Addr vaddr);
     Fault testWatchPoints(ThreadContext *tc, Addr vaddr, bool write,
                           bool atomic, unsigned size, bool cm);
-    Fault testVectorCatch(ThreadContext *tc, Addr addr, ArmFault* flt);
 
     Fault triggerException(ThreadContext * tc, Addr vaddr);
     Fault triggerWatchpointException(ThreadContext *tc, Addr vaddr,
                                      bool write, bool cm);
+  public:
+    Fault testVectorCatch(ThreadContext *tc, Addr addr, ArmFault* flt);
 
     inline BrkPoint* getBrkPoint(uint8_t index)
     {
diff --git a/src/arch/arm/tlb.cc b/src/arch/arm/tlb.cc
index f007f9317..db0d55c97 100644
--- a/src/arch/arm/tlb.cc
+++ b/src/arch/arm/tlb.cc
@@ -1213,24 +1213,9 @@ TLB::translateFs(const RequestPtr &req, ThreadContext *tc, Mode mode,
     //Check for Debug Exceptions
     if (fault == NoFault) {
         auto *isa = static_cast<ArmISA::ISA *>(tc->getIsaPtr());
-        SelfDebug * sd = isa->getSelfDebug();
-        if (mode == Execute)
-        {
-            const bool d_step = sd->getSstep()->advanceSS(tc);
-            if (!d_step) {
-                fault = sd->testVectorCatch(tc, req->getVaddr(), nullptr);
-                if (fault == NoFault)
-                    fault = sd->testBreakPoints(tc, req->getVaddr());
-            }
-        }
-        else if (!req->isCacheMaintenance() ||
-                 (req->isCacheInvalidate() && !req->isCacheClean())) {
-            bool md = mode == Write ? true: false;
-            fault = sd->testWatchPoints(tc, req->getVaddr(), md,
-                                        req->isAtomic(),
-                                        req->getSize(),
-                                        req->isCacheMaintenance());
-        }
+        SelfDebug *sd = isa->getSelfDebug();
+
+        fault = sd->testDebug(tc, req, mode);
     }
 
     return fault;
-- 
2.30.2