fastmodel: Add CortexA76 model reset port

The model reset is an aggregated logic to reset the whole model. The
port helps us to simulate the reboot process.

Change-Id: I9aacc398b299e26e4675f7229db1afc8f6c8a34f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/58814
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/arm/fastmodel/CortexA76/FastModelCortexA76.py

@@ -31,6 +31,7 @@ from m5.objects.ArmInterrupts import ArmInterrupts
 from m5.objects.ArmISA import ArmISA
 from m5.objects.FastModel import AmbaInitiatorSocket, AmbaTargetSocket
 from m5.objects.FastModelGIC import Gicv3CommsTargetSocket
+from m5.objects.ResetPort import ResetResponsePort
 from m5.objects.IntPin import IntSinkPin
 from m5.objects.Gic import ArmPPI
 from m5.objects.Iris import IrisBaseCPU
@@ -172,6 +173,7 @@ class FastModelCortexA76Cluster(SimObject):
             'all resettable registers in DynamIQ.')
     dbg_reset = IntSinkPin('Initialize the shared debug APB, Cross Trigger ' \
             'Interface (CTI), and Cross Trigger Matrix (CTM) logic.')
+    model_reset = ResetResponsePort('A reset port to reset the whole cluster.')
 
     # These parameters are described in "Fast Models Reference Manual" section
     # 3.4.19, "ARMCortexA7x1CT".

src/arch/arm/fastmodel/CortexA76/cortex_a76.cc

@@ -104,7 +104,8 @@ CortexA76::setResetAddr(Addr addr, bool secure)
 Port &
 CortexA76::getPort(const std::string &if_name, PortID idx)
 {
-    if (if_name == "redistributor" || if_name == "core_reset")
+    if (if_name == "redistributor" || if_name == "core_reset" ||
+        if_name == "poweron_reset")
         return cluster->getEvs()->gem5_getPort(if_name, num);
     else
         return Base::getPort(if_name, idx);
@@ -200,7 +201,7 @@ Port &
 CortexA76Cluster::getPort(const std::string &if_name, PortID idx)
 {
     if (if_name == "amba" || if_name == "top_reset" ||
-        if_name == "dbg_reset") {
+        if_name == "dbg_reset" || if_name == "model_reset") {
         return evs->gem5_getPort(if_name, idx);
     } else {
         return SimObject::getPort(if_name, idx);

src/arch/arm/fastmodel/CortexA76/evs.cc

@@ -70,6 +70,23 @@ ScxEvsCortexA76<Types>::setResetAddr(int core, Addr addr, bool secure)
     this->rvbaraddr[core]->set_state(0, addr);
 }
 
+template <class Types>
+void
+ScxEvsCortexA76<Types>::requestReset()
+{
+    // Reset all cores.
+    for (auto &poweron_reset : this->poweron_reset) {
+        poweron_reset->signal_out.set_state(0, true);
+        poweron_reset->signal_out.set_state(0, false);
+    }
+    // Reset DSU.
+    this->top_reset.signal_out.set_state(0, true);
+    this->top_reset.signal_out.set_state(0, false);
+    // Reset debug APB.
+    this->dbg_reset.signal_out.set_state(0, true);
+    this->dbg_reset.signal_out.set_state(0, false);
+}
+
 template <class Types>
 ScxEvsCortexA76<Types>::ScxEvsCortexA76(
         const sc_core::sc_module_name &mod_name, const Params &p) :
@@ -77,6 +94,7 @@ ScxEvsCortexA76<Types>::ScxEvsCortexA76(
     amba(Base::amba, p.name + ".amba", -1),
     top_reset(p.name + ".top_reset", 0),
     dbg_reset(p.name + ".dbg_reset", 0),
+    model_reset(p.name + ".model_reset", -1, this),
     params(p)
 {
     for (int i = 0; i < CoreCount; i++) {
@@ -178,6 +196,8 @@ ScxEvsCortexA76<Types>::gem5_getPort(const std::string &if_name, int idx)
         return top_reset;
     else if (if_name == "dbg_reset")
         return dbg_reset;
+    else if (if_name == "model_reset")
+        return model_reset;
     else
         return Base::gem5_getPort(if_name, idx);
 }

src/arch/arm/fastmodel/CortexA76/evs.hh

@@ -35,6 +35,7 @@
 #include "arch/arm/fastmodel/common/signal_sender.hh"
 #include "arch/arm/fastmodel/iris/cpu.hh"
 #include "arch/arm/fastmodel/protocol/exported_clock_rate_control.hh"
+#include "dev/reset_port.hh"
 #include "mem/port_proxy.hh"
 #include "params/FastModelScxEvsCortexA76x1.hh"
 #include "params/FastModelScxEvsCortexA76x2.hh"
@@ -98,6 +99,8 @@ class ScxEvsCortexA76 : public Types::Base, public Iris::BaseCpuEvs
 
     SignalSender dbg_reset;
 
+    ResetResponsePort<ScxEvsCortexA76> model_reset;
+
     CortexA76Cluster *gem5CpuCluster;
 
     const Params &params;
@@ -126,6 +129,8 @@ class ScxEvsCortexA76 : public Types::Base, public Iris::BaseCpuEvs
     void setCluster(SimObject *cluster) override;
 
     void setResetAddr(int core, Addr addr, bool secure) override;
+
+    void requestReset();
 };
 
 struct ScxEvsCortexA76x1Types