x86_64/memory: clean up dependencies

1 files changed, 3 insertions, 146 deletions

diff --git a/arch/x86_64/src/memory/paging_root.cpp b/arch/x86_64/src/memory/paging_root.cpp
index 078686b..4f88657 100644
--- a/arch/x86_64/src/memory/paging_root.cpp
+++ b/arch/x86_64/src/memory/paging_root.cpp
@@ -1,161 +1,18 @@
 #include "x86_64/memory/paging_root.hpp"
 
-#include "kapi/memory.hpp"
-#include "kapi/system.hpp"
-
-#include "x86_64/memory/page_table.hpp"
-#include "x86_64/memory/page_utilities.hpp"
-#include "x86_64/memory/scoped_mapping.hpp"
-
-#include <cstddef>
 #include <cstdint>
-#include <memory>
-#include <optional>
 
 namespace teachos::memory::x86_64
 {
 
   namespace
   {
-    constexpr auto PML_RECURSIVE_BASE = std::uintptr_t{0177777'776'776'776'776'0000uz};
-
-    //! Perform the actual mapping of the page, via the recursive page map.
-    //!
-    //! On any level above PML1, the entries need to not be no_execute, because the image is densely packed. The entries
-    //! also need to be writable, since the mapping is being performed through the recursive page map hierarchy. When
-    //! setting the final entry in the PML1, the actually desired flags are set as is, with the present bit added, thus
-    //! still enforcing non-writability and non-execution of the affected page.
-    template<std::size_t Level>
-      requires(Level > 1uz && Level < 5uz)
-    auto do_map(recursive_page_table<Level> * pml, page page, page_table::entry::flags flags)
-    {
-      auto index = pml_index<Level>(page);
-      flags = flags & ~page_table::entry::flags::no_execute;
-      flags = flags | page_table::entry::flags::writable;
-      if (!(*pml)[index].present())
-      {
-        auto new_table_frame = active_frame_allocator().allocate();
-        auto mapping = scoped_mapping{page};
-        (*pml)[index].frame(new_table_frame.value(), page_table::entry::flags::present | flags);
-        auto new_table = std::optional{std::construct_at(*pml->next(index))};
-        return new_table;
-      }
-      (*pml)[index] |= flags;
-      return pml->next(index);
-    }
-
-    //! Perform the actual PML1 update.
-    auto do_map(page_table * pml, page page, frame frame, page_table::entry::flags flags) -> std::optional<std::byte *>
-    {
-      auto index = pml_index<1>(page);
-      if ((*pml)[index].present())
-      {
-        system::panic("[x86_64:MEM] Tried to map a page that is already mapped");
-      }
-      (*pml)[index].frame(frame, page_table::entry::flags::present | flags);
-      return std::optional{static_cast<std::byte *>(page.start_address())};
-    }
+    constexpr auto recursive_base = std::uintptr_t{0177777'776'776'776'776'0000uz};
   }  // namespace
 
-  auto paging_root::get() -> paging_root &
-  {
-    auto pml4_address = std::bit_cast<paging_root *>(PML_RECURSIVE_BASE);
-    return *pml4_address;
-  }
-
-  auto paging_root::translate(linear_address address) const -> std::optional<physical_address>
-  {
-    auto offset = address.raw() % page::size;
-    return translate(page::containing(address)).transform([offset](auto frame) -> auto {
-      return physical_address{frame.start_address().raw() + offset};
-    });
-  }
-
-  auto paging_root::translate(page page) const -> std::optional<frame>
-  {
-    auto pml3 = next(pml_index<4>(page));
-
-    if (!pml3)
-    {
-      return std::nullopt;
-    }
-
-    auto handle_huge_page = [&] -> std::optional<frame> {
-      auto pml3_entry = pml3.transform([&](auto pml3) -> auto { return (*pml3)[pml_index<3>(page)]; });
-      if (!pml3_entry)
-      {
-        return std::nullopt;
-      }
-      else if (pml3_entry->huge())
-      {
-        auto pml3_entry_frame = *pml3_entry->frame();
-        return frame{pml3_entry_frame.number() + pml_index<2>(page) * entry_count + pml_index<1>(page)};
-      }
-
-      auto pml2 = (*pml3)->next(pml_index<3>(page));
-      auto pml2_entry = pml2.transform([&](auto pml2) -> auto { return (*pml2)[pml_index<2>(page)]; });
-      if (!pml2_entry)
-      {
-        return std::nullopt;
-      }
-      else if (pml2_entry->huge())
-      {
-        auto pml2_entry_frame = *pml2_entry->frame();
-        return frame{pml2_entry_frame.number() + pml_index<1>(page)};
-      }
-
-      return std::nullopt;
-    };
-
-    return pml3.and_then([&](auto pml3) -> auto { return pml3->next(pml_index<3>(page)); })
-        .and_then([&](auto pml2) -> auto { return pml2->next(pml_index<2>(page)); })
-        .and_then([&](auto pml1) -> auto { return (*pml1)[pml_index<1>(page)].frame(); })
-        .or_else(handle_huge_page);
-  }
-
-  auto paging_root::map(page page, frame frame, page_table::entry::flags flags) -> std::optional<std::byte *>
+  auto paging_root::get() -> paging_root *
   {
-    return std::optional{this}
-        .and_then([&](auto pml) -> auto { return do_map(pml, page, flags); })
-        .and_then([&](auto pml) -> auto { return do_map(pml, page, flags); })
-        .and_then([&](auto pml) -> auto { return do_map(pml, page, flags); })
-        .and_then([&](auto pml) -> auto { return do_map(pml, page, frame, flags); });
-  }
-
-  auto paging_root::unmap(page page) -> void
-  {
-    if (!this->translate(page))
-    {
-      system::panic("[x86_64:MEM] Tried to unmap a page that was not mapped.");
-    }
-
-    auto pml4 = this;
-    auto pml3 = pml4->next(pml_index<4>(page)).value();
-    auto pml2 = pml3->next(pml_index<3>(page)).value();
-    auto pml1 = pml2->next(pml_index<2>(page)).value();
-
-    (*pml1)[pml_index<1>(page)].clear();
-
-    if (pml1->empty())
-    {
-      auto pml1_frame = (*pml2)[pml_index<2>(page)].frame().value();
-      active_frame_allocator().release(pml1_frame);
-      (*pml2)[pml_index<2>(page)].clear();
-    }
-
-    if (pml2->empty())
-    {
-      auto pml2_frame = (*pml3)[pml_index<3>(page)].frame().value();
-      active_frame_allocator().release(pml2_frame);
-      (*pml3)[pml_index<3>(page)].clear();
-    }
-
-    if (pml3->empty())
-    {
-      auto pml3_frame = (*pml4)[pml_index<4>(page)].frame().value();
-      active_frame_allocator().release(pml3_frame);
-      (*pml4)[pml_index<4>(page)].clear();
-    }
+    return std::bit_cast<paging_root *>(recursive_base);
   }
 
 }  // namespace teachos::memory::x86_64
\ No newline at end of file