moves mmu related code into mmu unit

src/iss/mem/memory_if.cpp

@@ -0,0 +1,67 @@
+#include "memory_if.h"
+#include <algorithm>
+
+namespace iss {
+namespace mem {
+void memory_hierarchy::root(memory_elem& e) {
+    hierarchy.push_front(&e);
+    root_set=true;
+    update_chain();
+}
+void memory_hierarchy::prepend(memory_elem& e) {
+    if(root_set)
+        hierarchy.insert(hierarchy.begin()+1, &e);
+    else
+        hierarchy.push_front(&e);
+    update_chain();
+}
+void memory_hierarchy::append(memory_elem& e) {
+    hierarchy.push_back(&e);
+    update_chain();
+}
+void memory_hierarchy::insert_before(memory_elem&) {}
+void memory_hierarchy::insert_after(memory_elem&) {}
+void memory_hierarchy::replace_last(memory_elem& e) {
+    hierarchy.pop_back();
+    hierarchy.push_back(&e);
+}
+void memory_hierarchy::update_chain() {
+    bool tail = false;
+    for(size_t i = 0; i < hierarchy.size(); ++i) {
+        hierarchy[i]->register_csrs();
+        if(i)
+            hierarchy[i - 1]->set_next(hierarchy[i]->get_mem_if());
+    }
+}
+
+void memory_hierarchy::prepend(std::unique_ptr<memory_elem>&& p) {
+    prepend(*p);
+    owned_elems.push_back(std::move(p));
+}
+
+void memory_hierarchy::append(std::unique_ptr<memory_elem>&& p) {
+    append(*p);
+    owned_elems.push_back(std::move(p));
+}
+
+void memory_hierarchy::insert_before(std::unique_ptr<memory_elem>&& p) {
+    insert_before(*p);
+    owned_elems.push_back(std::move(p));
+}
+
+void memory_hierarchy::insert_after(std::unique_ptr<memory_elem>&& p) {
+    insert_after(*p);
+    owned_elems.push_back(std::move(p));
+}
+
+void memory_hierarchy::replace_last(std::unique_ptr<memory_elem>&& p) {
+    auto e = hierarchy.back();
+    replace_last(*p);
+    auto it  = std::find_if(std::begin(owned_elems), std::end(owned_elems), [e](std::unique_ptr<memory_elem> const& p) {return p.get()==e;});
+    if(it!=std::end(owned_elems))
+        owned_elems.erase(it);
+    owned_elems.push_back(std::move(p));
+}
+
+} // namespace mem
+} // namespace iss