diff options
Diffstat (limited to 'arch/x86_64/include')
| -rw-r--r-- | arch/x86_64/include/arch/memory/paging/page_mapper.hpp | 4 | ||||
| -rw-r--r-- | arch/x86_64/include/arch/memory/paging/page_table.hpp | 77 | ||||
| -rw-r--r-- | arch/x86_64/include/arch/memory/paging/virtual_page.hpp | 2 |
3 files changed, 22 insertions, 61 deletions
diff --git a/arch/x86_64/include/arch/memory/paging/page_mapper.hpp b/arch/x86_64/include/arch/memory/paging/page_mapper.hpp index a874f75..0806f58 100644 --- a/arch/x86_64/include/arch/memory/paging/page_mapper.hpp +++ b/arch/x86_64/include/arch/memory/paging/page_mapper.hpp @@ -60,7 +60,7 @@ namespace teachos::arch::memory::paging { auto current_handle = create_or_get(); - for (auto level = page_table::LEVEL4; level != page_table::LEVEL1; level--) + for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; level--) { auto level_index = page.get_level_index(level); auto next_handle = current_handle.next_table(level_index); @@ -82,7 +82,7 @@ namespace teachos::arch::memory::paging current_handle = next_handle.value(); } - auto level1_entry = current_handle[page.get_level_index(page_table::LEVEL1)]; + auto level1_entry = current_handle[page.get_level_index(page_table_handle::LEVEL1)]; arch::exception_handling::assert(!level1_entry.contains_flags(entry::HUGE_PAGE), "[Page Mapper] Unable to map huge pages"); arch::exception_handling::assert(!level1_entry.is_unused(), "[Page Mapper] Page table entry is already used"); diff --git a/arch/x86_64/include/arch/memory/paging/page_table.hpp b/arch/x86_64/include/arch/memory/paging/page_table.hpp index a1c8abe..91ce81c 100644 --- a/arch/x86_64/include/arch/memory/paging/page_table.hpp +++ b/arch/x86_64/include/arch/memory/paging/page_table.hpp @@ -11,12 +11,20 @@ namespace teachos::arch::memory::paging } /** - * @brief A Page table containing 512 entries. + * @brief Forward delcaration of the page_table, because it should only be accessible over the handle, the actual + * methods or constructor are not defined meaning they are not callable from outside. Instead the struct is only fully + * defined in the implementation (.cpp) file of the page table, and therefore also only accesible in that file. */ - struct page_table + struct page_table; + + /** + * @brief Handle that ensures accessing the page table is safe because it adds additional checks to the next_table + * method and ensures it can only be called if the table level is not LEVEL1. + */ + struct page_table_handle { /** - * @brief Level of the page table, level 1 should not be able to call next_table anymore, because it would result in + * @brief Level of the page table, level 1 will not be able to call next_table anymore, because it would result in * attempting to access memory that it should not. */ enum level : uint8_t @@ -28,61 +36,12 @@ namespace teachos::arch::memory::paging }; /** - * @brief Deleted constructor. Object can only be created by casting from the fixed Level 4 - * page table address `reinterpret_cast<page_table *>(0xfffffffffffff000)`. - */ - page_table() = delete; - - /** - * @brief Set every entry of the page to unused. - */ - auto zero_entries() -> void; - - /** - * @brief Returns the next page table level from the given page table index. Meaning we - * use an index into a Level 4 page table to get the according Level 3 page table. This method should not be called - * on a Level 1 page table, because there is no furthere page table and mangeling up and returning the physical - * address would cause hard to debug issues. - * - * @param table_index Index of this page table in the page table one level lower. - */ - auto next_table(std::size_t table_index) const -> std::optional<page_table *>; - - /** - * @brief Index operator overload to access specific entries directy. - * - * @param index Index of the entry we want to access and read or write too. - * @return Entry at the given table index. - */ - auto operator[](std::size_t index) const -> entry; - - private: - /** - * @brief Calculates the address of the next page table level for the given table index. The next page table address - * is only valid if the corresponding entry is present and not a huge page. Meaning we use an index into a - * Level 4 page table to get the according Level 3 page table address. - * - * @param table_index Index of this page table in the page table one level higher. - * @return An optional of the address of the next page table or null. - */ - auto next_table_address(std::size_t table_index) const -> std::optional<std::size_t>; - - entry entries[PAGE_TABLE_ENTRY_COUNT]; ///< Entries containing addresses to page tables of a level below or actual - ///< virtual addresses for the level 1 page table. - }; - - auto operator--(page_table::level & level, int) -> page_table::level; - - /** - * @brief Handle that ensures accessing the page table is safe because it adds additional checks to the next_table - * method and ensures it can only be called if the table level is not LEVEL1. - */ - struct page_table_handle - { - /** * @brief Constructor. + * + * @param handle Underlying page table the handle should point to. + * @param handle_level Level the underlying page table is on, used to ensure safety. */ - page_table_handle(page_table * handle, page_table::level handle_level); + page_table_handle(page_table * handle, level handle_level); /** * @brief Set every entry of the page to unused. @@ -109,9 +68,11 @@ namespace teachos::arch::memory::paging private: page_table * handle; ///< Handle to underlying page table, can never be null (invariant ensured by constructor) - page_table::level handle_level; ///< Level page table is currently on, depends on how often next_level was - ///< called successfully. + level handle_level; ///< Level page table is currently on, depends on how often next_level was + ///< called successfully. }; + + auto operator--(page_table_handle::level & level, int) -> page_table_handle::level; } // namespace teachos::arch::memory::paging #endif // TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_TABLE_HPP diff --git a/arch/x86_64/include/arch/memory/paging/virtual_page.hpp b/arch/x86_64/include/arch/memory/paging/virtual_page.hpp index f8dfbf0..ca11b3c 100644 --- a/arch/x86_64/include/arch/memory/paging/virtual_page.hpp +++ b/arch/x86_64/include/arch/memory/paging/virtual_page.hpp @@ -43,7 +43,7 @@ namespace teachos::arch::memory::paging * @param level Level of the page table we want to calculate the index for. * @return Index into the page table with the given level. */ - auto get_level_index(page_table::level level) const -> uint64_t; + auto get_level_index(page_table_handle::level level) const -> uint64_t; /** * @brief Defaulted equals operator. |