x86_64/memory: clean up dependencies

4 files changed, 62 insertions, 24 deletions

diff --git a/arch/x86_64/include/x86_64/memory/kernel_mapper.hpp b/arch/x86_64/include/x86_64/memory/kernel_mapper.hpp
index 1f217ae..5b9c2fd 100644
--- a/arch/x86_64/include/x86_64/memory/kernel_mapper.hpp
+++ b/arch/x86_64/include/x86_64/memory/kernel_mapper.hpp
@@ -1,6 +1,8 @@
 #ifndef TEACHOS_X86_64_KERNEL_MAPPER_HPP
 #define TEACHOS_X86_64_KERNEL_MAPPER_HPP
 
+#include "kapi/memory.hpp"
+
 #include <elf/format.hpp>
 #include <elf/section_header.hpp>
 #include <multiboot2/information.hpp>
@@ -16,10 +18,10 @@ namespace teachos::memory::x86_64
 
     explicit kernel_mapper(multiboot2::information_view const * mbi);
 
-    auto remap_kernel() -> void;
+    auto remap_kernel(page_mapper & mapper) -> void;
 
   private:
-    auto map_section(section_header_type const & section, std::string_view name) -> void;
+    auto map_section(section_header_type const & section, std::string_view name, page_mapper & mapper) -> void;
 
     multiboot2::information_view const * m_mbi;
     std::uintptr_t m_kernel_load_base;
diff --git a/arch/x86_64/include/x86_64/memory/page_table.hpp b/arch/x86_64/include/x86_64/memory/page_table.hpp
index 3bc2a2b..71ba5b7 100644
--- a/arch/x86_64/include/x86_64/memory/page_table.hpp
+++ b/arch/x86_64/include/x86_64/memory/page_table.hpp
@@ -3,6 +3,8 @@
 
 #include "kapi/memory.hpp"
 
+#include "x86_64/memory/page_utilities.hpp"
+
 #include <kstd/ext/bitfield_enum>
 
 #include <array>
@@ -183,6 +185,58 @@ namespace teachos::memory::x86_64
       });
     }
 
+    [[nodiscard]] auto translate(linear_address address) const -> std::optional<physical_address>
+      requires(Level == 4)
+    {
+      auto offset = address.raw() % page::size;
+      return translate(page::containing(address)).transform([offset](auto frame) -> auto {
+        return physical_address{frame.start_address().raw() + offset};
+      });
+    }
+
+    [[nodiscard]] auto translate(page page) const -> std::optional<frame>
+      requires(Level == 4)
+    {
+      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);
+    }
+
   private:
     //! The number of address bits used to represent the page index per level.
     constexpr auto static level_bits = 9;
diff --git a/arch/x86_64/include/x86_64/memory/paging_root.hpp b/arch/x86_64/include/x86_64/memory/paging_root.hpp
index 75ba120..47ee2f9 100644
--- a/arch/x86_64/include/x86_64/memory/paging_root.hpp
+++ b/arch/x86_64/include/x86_64/memory/paging_root.hpp
@@ -1,19 +1,15 @@
 #ifndef TEACHOS_X86_64_PAGING_ROOT_HPP
 #define TEACHOS_X86_64_PAGING_ROOT_HPP
 
-#include "kapi/memory.hpp"
-
 #include "x86_64/memory/page_table.hpp"
 
-#include <optional>
-
 namespace teachos::memory::x86_64
 {
 
   //! The active, recursively mapped, root map (e.g. PML4)
   struct paging_root : recursive_page_table<4>
   {
-    auto static get() -> paging_root &;
+    auto static get() -> paging_root *;
 
     paging_root(paging_root const &) = delete;
     paging_root(paging_root &&) = delete;
@@ -22,22 +18,6 @@ namespace teachos::memory::x86_64
 
     ~paging_root() = delete;
 
-    [[nodiscard]] auto translate(linear_address address) const -> std::optional<physical_address>;
-    [[nodiscard]] auto translate(page page) const -> std::optional<frame>;
-
-    //! Map the given page into the given frame using the given flags.
-    //!
-    //! @param page A page to map.
-    //! @param frame The frame into which to map the page.
-    //! @param flags The flags to apply to the mapping.
-    auto map(page page, frame frame, entry::flags flags) -> std::optional<std::byte *>;
-
-    //! Unmap the given page from virtual memory.
-    //!
-    //! @warning If the page has not previously been mapped, this function will panic.
-    //! @param page The page to unmap
-    auto unmap(page page) -> void;
-
   private:
     paging_root() = default;
   };
diff --git a/arch/x86_64/include/x86_64/memory/scoped_mapping.hpp b/arch/x86_64/include/x86_64/memory/scoped_mapping.hpp
index 415ea8e..835e2df 100644
--- a/arch/x86_64/include/x86_64/memory/scoped_mapping.hpp
+++ b/arch/x86_64/include/x86_64/memory/scoped_mapping.hpp
@@ -22,7 +22,8 @@ namespace teachos::memory::x86_64
 
     //! Construct a new scoped mapping, which can be used to map a frame to the given unused page.
     //! @param page An unused page. If the page is already mapped, this constructor will panic.
-    explicit scoped_mapping(page page);
+    //! @param mapper The page mapper to use for mapping and unmapping of the page.
+    explicit scoped_mapping(page page, page_mapper & mapper);
 
     //! Unmap the mapped frame if one was mapped.
     //! @note Any page tables that were allocated to support the mapping will be released.
@@ -56,6 +57,7 @@ namespace teachos::memory::x86_64
 
   private:
     page m_page;
+    page_mapper * m_mapper;
     bool m_mapped;
   };