kapi: move frame and address to KAPI

3 files changed, 143 insertions, 1 deletions

diff --git a/kapi/include/kapi/memory.hpp b/kapi/include/kapi/memory.hpp
index 842a2fa..3ad5ac5 100644
--- a/kapi/include/kapi/memory.hpp
+++ b/kapi/include/kapi/memory.hpp
@@ -1,9 +1,12 @@
 #ifndef TEACHOS_KAPI_MEMORY_HPP
 #define TEACHOS_KAPI_MEMORY_HPP
 
+#include "kapi/memory/address.hpp"  // IWYU pragma: export
+#include "kapi/memory/frame.hpp"    // IWYU pragma: export
+
 namespace teachos::memory
 {
   auto init() -> void;
-}
+}  // namespace teachos::memory
 
 #endif
diff --git a/kapi/include/kapi/memory/address.hpp b/kapi/include/kapi/memory/address.hpp
new file mode 100644
index 0000000..585807a
--- /dev/null
+++ b/kapi/include/kapi/memory/address.hpp
@@ -0,0 +1,47 @@
+#ifndef TEACHOS_KAPI_MEMORY_ADDRESS_HPP
+#define TEACHOS_KAPI_MEMORY_ADDRESS_HPP
+
+#include <bit>
+#include <compare>
+#include <cstddef>
+#include <cstdint>
+
+namespace teachos::memory
+{
+
+  enum struct address_type : bool
+  {
+    linear,
+    physical,
+  };
+
+  template<address_type Type>
+  struct address
+  {
+    constexpr explicit address(std::uintptr_t value) noexcept
+        : m_value{value}
+    {
+    }
+
+    explicit address(std::byte * pointer) noexcept
+        : m_value{std::bit_cast<std::uintptr_t>(pointer)}
+    {
+    }
+
+    explicit operator std::byte *() const noexcept { return std::bit_cast<std::byte *>(m_value); }
+
+    auto constexpr operator<=>(address const &) const noexcept -> std::strong_ordering = default;
+    auto constexpr operator==(address const &) const noexcept -> bool = default;
+
+    auto constexpr raw() const noexcept -> std::uintptr_t { return m_value; }
+
+  private:
+    std::uintptr_t m_value{};
+  };
+
+  using linear_address = address<address_type::linear>;
+  using physical_address = address<address_type::physical>;
+
+}  // namespace teachos::memory
+
+#endif
\ No newline at end of file
diff --git a/kapi/include/kapi/memory/frame.hpp b/kapi/include/kapi/memory/frame.hpp
new file mode 100644
index 0000000..1251e51
--- /dev/null
+++ b/kapi/include/kapi/memory/frame.hpp
@@ -0,0 +1,92 @@
+#ifndef TEACHOS_KAPI_MEMORY_FRAME_HPP
+#define TEACHOS_KAPI_MEMORY_FRAME_HPP
+
+#include "kapi/memory/address.hpp"
+
+#include <bit>
+#include <compare>
+#include <cstddef>
+#include <cstdint>
+
+namespace teachos::memory
+{
+
+  extern std::size_t const PLATFORM_FRAME_SIZE;
+
+  struct frame
+  {
+    constexpr frame() = default;
+
+    explicit constexpr frame(std::size_t number)
+        : m_number{number}
+    {
+    }
+
+    /**
+     * @brief Returns the physical frame the given address is contained in.
+     *
+     * @param address Physical address we want to get the corresponding physical frame for.
+     * @return Frame the given address is contained in.
+     */
+    auto constexpr static containing(physical_address address) noexcept -> frame
+    {
+      return frame{address.raw() / PLATFORM_FRAME_SIZE};
+    }
+
+    /**
+     * @brief Get the start address of this physical frame.
+     *
+     * @return Start address of the physical frame.
+     */
+    auto constexpr start_address() const noexcept -> physical_address
+    {
+      return physical_address{m_number * PLATFORM_FRAME_SIZE};
+    }
+
+    /**
+     * @brief Get the nth next frame.
+     *
+     * @param offset
+     * @return A new frame n frames after this one.
+     */
+    auto constexpr operator+(std::size_t n) const noexcept -> frame { return frame{m_number + n}; }
+
+    /**
+     * @brief Increment this frame to refer to the next one, returning a copy.
+     *
+     * @return Copy of the incremented underlying frame number.
+     */
+    auto constexpr operator++(int) noexcept -> frame
+    {
+      auto copy = *this;
+      return ++copy;
+    }
+
+    /**
+     * @brief Increment this frame to refer to the next one, returning a this frame.
+     *
+     * @return Reference to the incremented underlying frame number.
+     */
+    auto constexpr operator++() noexcept -> frame &
+    {
+      ++m_number;
+      return *this;
+    }
+
+    /**
+     * @brief Check if this frame refers to the same frame as @p other.
+     */
+    auto constexpr operator==(frame const & other) const noexcept -> bool = default;
+
+    /**
+     * @brief Lexicographically compare this frame to @p other.
+     */
+    auto constexpr operator<=>(frame const & other) const noexcept -> std::strong_ordering = default;
+
+  private:
+    std::size_t m_number{};
+  };
+
+}  // namespace teachos::memory
+
+#endif
\ No newline at end of file