diff options
6 files changed, 242 insertions, 93 deletions
diff --git a/arch/x86_64/include/arch/memory/allocator/area_frame_allocator.hpp b/arch/x86_64/include/arch/memory/allocator/area_frame_allocator.hpp index a1b771e..8e971f0 100644 --- a/arch/x86_64/include/arch/memory/allocator/area_frame_allocator.hpp +++ b/arch/x86_64/include/arch/memory/allocator/area_frame_allocator.hpp @@ -45,22 +45,6 @@ namespace teachos::arch::memory::allocator */ auto deallocate_frame(physical_frame physical_frame) -> void; - /** - * @brief Returns the iterator pointing to the first element of the memory area. - * Allows using this class in the for each loop, because it follows the InputIterator template scheme. - * - * @return Iterator pointing to first element of the memory area. - */ - auto begin() -> multiboot::memory_area_iterator; - - /** - * @brief Returns the iterator pointing to one past the last element of the memory area. - * Allows using this class in the for each loop, because it follows the InputIterator template scheme. - * - * @return Iterator pointing to one past the last element of the memory area. - */ - auto end() -> multiboot::memory_area_iterator; - private: /** * @brief Find the next memory area and write it into current_area. @@ -69,12 +53,12 @@ namespace teachos::arch::memory::allocator physical_frame next_free_frame; ///< The physical_frame after the last allocated one. std::optional<multiboot::memory_area> current_area; ///< The current memory area. - multiboot::memory_area_iterator area_begin; ///< Pointer to the first element of all memory areas. - multiboot::memory_area_iterator area_end; ///< Pointer to one pas the last element of all memory areas. - physical_frame const kernel_start; ///< The start address of the kernel code in memory. - physical_frame const kernel_end; ///< The end address of the kernel code in memory. - physical_frame const multiboot_start; ///< The start address of the multiboot code in memory. - physical_frame const multiboot_end; ///< The end address of the multiboot code in memory. + multiboot::memory_area_container const + memory_areas; ///< All memory areas in custom container allows to use std::ranges + physical_frame const kernel_start; ///< The start address of the kernel code in memory. + physical_frame const kernel_end; ///< The end address of the kernel code in memory. + physical_frame const multiboot_start; ///< The start address of the multiboot code in memory. + physical_frame const multiboot_end; ///< The end address of the multiboot code in memory. }; } // namespace teachos::arch::memory::allocator diff --git a/arch/x86_64/include/arch/memory/multiboot/memory_map.hpp b/arch/x86_64/include/arch/memory/multiboot/memory_map.hpp index e30d2c4..f9c902a 100644 --- a/arch/x86_64/include/arch/memory/multiboot/memory_map.hpp +++ b/arch/x86_64/include/arch/memory/multiboot/memory_map.hpp @@ -3,6 +3,7 @@ #include "info.hpp" #include <cstdint> +#include <iterator> namespace teachos::arch::memory::multiboot { @@ -44,48 +45,175 @@ namespace teachos::arch::memory::multiboot }; /** - * @brief Iterator for memory areas. + * @brief Random access iterator for memory areas. */ struct memory_area_iterator { + using iterator_category = std::random_access_iterator_tag; ///< Iterator category of this type. + using difference_type = std::ptrdiff_t; ///< Type when diving one instance of this iterator by another. + using value_type = memory_area; ///< Underlying value pointed to by this iterator. + + /** + * @brief Defaulted constructor. + */ + memory_area_iterator() = default; + /** * @brief Constructor. * - * @param p Underlying address the iterator should point too, ensure to not pass an invalid pointer. + * @param p Underlying address the iterator should point too, ensure to not pass an invalid pointer or the + * constructor will halt execution. */ - explicit memory_area_iterator(memory_area * p); + explicit memory_area_iterator(value_type * p); /** * @brief Dereferences the initally given pointer to its value. * * @return Reference to the value. */ - memory_area & operator*() const; + auto operator*() const -> value_type &; + + /** + * @brief Get underlying value, which is the intially passed pointer. + * + * @return Underlying value passed intially. + */ + auto operator->() const -> value_type *; /** * @brief Post increment operator. Returns a copy of the value. * * @return Copy of the incremented underlying address. */ - memory_area_iterator operator++(int); + auto operator++(int) -> memory_area_iterator; /** * @brief Pre increment operator. Returns a reference to the changed value. * * @return Reference to the incremented underlying address. */ - memory_area_iterator & operator++(); + auto operator++() -> memory_area_iterator &; + + /** + * @brief Addition assignment operator. Returns a reference to the changed value. + * + * @param value Value we want to add to the underlying address. + * @return Reference to the changed underlying address. + */ + auto operator+=(difference_type value) -> memory_area_iterator &; + + /** + * @brief Subtraction assignment operator. Returns a reference to the changed value. + * + * @param value Value we want to subtract from the underlying address. + * @return Reference to the changed underlying address. + */ + auto operator-=(difference_type value) -> memory_area_iterator &; + + /** + * @brief Addition operator. Returns the changed value. + * + * @param value Value we want to add to a copy of the underlying address. + * @return Copy of underlying address incremented by the given value. + */ + auto operator+(difference_type value) const -> memory_area_iterator; + + /** + * @brief Subtraction operator. Returns the changed value. + * + * @param value Value we want to subtrcat from a copy of the underlying address. + * @return Copy of underlying address decremented by the given value. + */ + auto operator-(difference_type value) const -> memory_area_iterator; + + /** + * @brief Subtraction operator. Returns the size difference between two iterators. + * + * @param other Other iterator we want to substract the underlying address with ours. + * @return Size difference between the underlying address of this instance and the given iterator. + */ + auto operator-(const memory_area_iterator & other) const -> difference_type; + + /** + * @brief Index operator overload. Returns a reference to the value at the given index. Simply returns the + * dereferenced underlying pointer incremented by the given index. + * + * @param index Index we want to access and get the value from. + * @return Reference to the value at the given index. + */ + auto operator[](difference_type index) const -> value_type &; /** * @brief Defaulted comparsion operator. Simply compares the memory address of both iterators. * * @param other Other iterator to compare to. - * @return Whether poith iterators point to the same underlying address in memory. + * @return Whether both iterators point to the same underlying address in memory. + */ + auto operator==(memory_area_iterator const & other) const -> bool = default; + + /** + * @brief Defaulted threeway comparsion operator. Simply compares the memory address of both iterators. + * + * @param other Other iterator to compare to. + * @return Whether the given iterator is smaller or larger than this iterator. + */ + auto operator<=>(memory_area_iterator const & other) const -> std::strong_ordering = default; + + private: + value_type * ptr; ///< Underlying address the iterator is currently pointing too. + }; + + /** + * @brief Read-only container for memory areas, that allow to easily use the memory_area_iterator in C++20 ranges + * calls. + */ + struct memory_area_container + { + using iterator = memory_area_iterator; ///< Iterators used by this container. + using size_type = std::size_t; ///< Maximum size of this container. + + /** + * @brief Constructor. + * + * @param begin Pointer to the first memory area, will be used to construct the begin iterator. + * @param size Amount of entries in the container we want to construct. + */ + memory_area_container(memory_area_iterator::value_type * begin, size_type size); + + /** + * @brief Returns the iterator pointing to the first element of the memory area. + * Allows using this class in the for each loop, because it follows the InputIterator template scheme. + * + * @return Iterator pointing to first element of the memory area. + */ + auto begin() const -> iterator; + + /** + * @brief Returns the iterator pointing to one past the last element of the memory area. + * Allows using this class in the for each loop, because it follows the InputIterator template scheme. + * + * @return Iterator pointing to one past the last element of the memory area. + */ + auto end() const -> iterator; + + /** + * @brief Calculates the size of this container, simply subtracts the iterator pointing to the first element by the + * last. + * + * @return Actual size of this container. + */ + auto size() const -> size_type; + + /** + * @brief Calcualtes the size and returns true if the size is 0 and the container therefore emtpy. + * + * @return Whether the container is empty, size being 0 or not */ - bool operator==(memory_area_iterator const & other) const = default; + auto empty() const -> bool; private: - memory_area * ptr; ///< Underlying address the iterator is currently pointing too. + iterator area_begin; ///< Pointer to the first element of all memory areas. + iterator area_end; ///< Pointer to one pas the last element of all memory areas. }; } // namespace teachos::arch::memory::multiboot 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 4905e9e..7a8e2c9 100644 --- a/arch/x86_64/include/arch/memory/paging/page_mapper.hpp +++ b/arch/x86_64/include/arch/memory/paging/page_mapper.hpp @@ -95,7 +95,7 @@ namespace teachos::arch::memory::paging auto map_next_free_page_to_frame(T & allocator, virtual_page page, std::bitset<64U> flags) -> void { auto frame = allocator.allocate_frame(); - exception_handling::assert(!frame.has_value(), "[Page mapper] Out of memory exception"); + exception_handling::assert(frame.has_value(), "[Page mapper] Out of memory exception"); map_page_to_frame(allocator, page, frame.value(), flags); } diff --git a/arch/x86_64/src/kernel/main.cpp b/arch/x86_64/src/kernel/main.cpp index ad1eb39..5186c21 100644 --- a/arch/x86_64/src/kernel/main.cpp +++ b/arch/x86_64/src/kernel/main.cpp @@ -22,11 +22,8 @@ namespace teachos::arch::kernel size_t address = 42 * memory::paging::PAGE_TABLE_ENTRY_COUNT * memory::paging::PAGE_TABLE_ENTRY_COUNT * memory::allocator::PAGE_FRAME_SIZE; // 42th P3 entry auto page = memory::paging::virtual_page::containing_address(address); - auto frame = allocator.allocate_frame(); - exception_handling::assert(frame.has_value(), "[Main] Out of memory exception"); + memory::paging::map_next_free_page_to_frame(allocator, page, 0U); auto optional_frame = memory::paging::translate_page(page); - memory::paging::map_page_to_frame(allocator, page, frame.value(), 0U); - optional_frame = memory::paging::translate_page(page); video::vga::text::newline(); video::vga::text::write("Mapped physical frame: ", video::vga::text::common_attributes::green_on_black); video::vga::text::write_number(optional_frame.value().frame_number, diff --git a/arch/x86_64/src/memory/allocator/area_frame_allocator.cpp b/arch/x86_64/src/memory/allocator/area_frame_allocator.cpp index 05b828c..6ed4f28 100644 --- a/arch/x86_64/src/memory/allocator/area_frame_allocator.cpp +++ b/arch/x86_64/src/memory/allocator/area_frame_allocator.cpp @@ -2,13 +2,16 @@ #include "arch/exception_handling/assert.hpp" +#include <algorithm> +#include <array> +#include <ranges> + namespace teachos::arch::memory::allocator { area_frame_allocator::area_frame_allocator(multiboot::memory_information mem_info) : next_free_frame(0) , current_area(std::nullopt) - , area_begin(mem_info.memory_areas) - , area_end(mem_info.memory_areas + mem_info.area_count) + , memory_areas(mem_info.memory_areas, mem_info.area_count) , kernel_start(physical_frame::containing_address(mem_info.kernel_start)) , kernel_end(physical_frame::containing_address(mem_info.kernel_end)) , multiboot_start(physical_frame::containing_address(mem_info.multiboot_start)) @@ -20,26 +23,21 @@ namespace teachos::arch::memory::allocator auto area_frame_allocator::choose_next_area() -> void { current_area = std::nullopt; + auto next_area_with_free_frames = memory_areas | std::views::filter([this](multiboot::memory_area const & area) { + auto address = area.base_address + area.area_length - 1; + return physical_frame::containing_address(address) >= next_free_frame; + }); - for (multiboot::memory_area_iterator it = begin(); it != end(); ++it) - { - multiboot::memory_area & area = *it; + auto lowest_area_with_free_frames = + std::ranges::min_element(next_area_with_free_frames, [](multiboot::memory_area a, multiboot::memory_area b) { + return a.base_address < b.base_address; + }); - std::size_t address = area.base_address + area.area_length - 1; - if (physical_frame::containing_address(address) >= next_free_frame) - { - // The `next_free_frame` address is smaller than the last address of the current area - if (!current_area.has_value() || area.base_address < current_area.value().base_address) - { - current_area.emplace(area); - } - } - } - - if (current_area.has_value()) + if (lowest_area_with_free_frames != next_area_with_free_frames.end()) { + current_area = *lowest_area_with_free_frames; // Update the `next_free_frame` according to the new memory area - physical_frame start_frame = physical_frame::containing_address(current_area->base_address); + auto start_frame = physical_frame::containing_address(current_area.value().base_address); if (next_free_frame < start_frame) { next_free_frame = start_frame; @@ -53,41 +51,38 @@ namespace teachos::arch::memory::allocator * Only try to allocate memory if current_area is not null, because * the current_area is null if there is no more available memory. */ - if (current_area.has_value()) + if (!current_area.has_value()) { - physical_frame physical_frame{next_free_frame.frame_number}; + return std::nullopt; + } - struct physical_frame current_area_last_frame = { - physical_frame::containing_address(current_area->base_address + current_area->area_length - 1)}; + auto address = current_area.value().base_address + current_area.value().area_length - 1; + physical_frame current_area_last_frame = physical_frame::containing_address(address); - if (next_free_frame > current_area_last_frame) - { - // All frames of current area are used, switch to next area - choose_next_area(); - } - else if (physical_frame >= kernel_start && physical_frame <= kernel_end) - { - // `physical_frame` is used by the kernel - next_free_frame = allocator::physical_frame{kernel_end.frame_number + 1}; - } - else if (physical_frame >= multiboot_start && physical_frame <= multiboot_end) - { - // `physical_frame` is used by the multiboot information structure - next_free_frame = allocator::physical_frame{multiboot_end.frame_number + 1}; - } - else - { - // Frame is unused, increment `next_free_frame` and return it - next_free_frame.frame_number += 1; - return physical_frame; - } - - // `physical_frame` was not valid, try it again with the updated `next_free_frame` - return allocate_frame(); + if (next_free_frame > current_area_last_frame) + { + // All frames of current area are used, switch to next area. + choose_next_area(); + } + else if (next_free_frame >= kernel_start && next_free_frame <= kernel_end) + { + // `physical_frame` is used by the kernel or multiboot information structure. + next_free_frame = allocator::physical_frame{kernel_end.frame_number + 1}; + } + else if (next_free_frame >= multiboot_start && next_free_frame <= multiboot_end) + { + // `physical_frame` is used by the kernel or multiboot information structure. + next_free_frame = allocator::physical_frame{multiboot_end.frame_number + 1}; + } + else + { + // Frame is unused, increment `next_free_frame` and return it. + next_free_frame.frame_number += 1; + return next_free_frame; } - // no free frames left - return std::nullopt; + // `physical_frame` was not valid, try it again with the updated `next_free_frame`. + return allocate_frame(); } auto area_frame_allocator::deallocate_frame(physical_frame physical_frame) -> void @@ -95,8 +90,4 @@ namespace teachos::arch::memory::allocator exception_handling::assert(false && physical_frame.frame_number == 0, "[deallocate_frame] Not implemented Exception"); } - - auto area_frame_allocator::begin() -> multiboot::memory_area_iterator { return area_begin; } - - auto area_frame_allocator::end() -> multiboot::memory_area_iterator { return area_end; } } // namespace teachos::arch::memory::allocator diff --git a/arch/x86_64/src/memory/multiboot/memory_map.cpp b/arch/x86_64/src/memory/multiboot/memory_map.cpp index 6b1d1d4..b5e2759 100644 --- a/arch/x86_64/src/memory/multiboot/memory_map.cpp +++ b/arch/x86_64/src/memory/multiboot/memory_map.cpp @@ -1,19 +1,24 @@ #include "arch/memory/multiboot/memory_map.hpp" +#include "arch/exception_handling/assert.hpp" + namespace teachos::arch::memory::multiboot { - memory_area_iterator::memory_area_iterator(multiboot::memory_area * p) + memory_area_iterator::memory_area_iterator(value_type * p) : ptr(p) { - // Nothing to do + exception_handling::assert(ptr, "[Memory Area] Attempted to pass nullptr as iterator"); } - multiboot::memory_area & memory_area_iterator::operator*() const { return *ptr; } + auto memory_area_iterator::operator*() const -> value_type & { return *ptr; } + + auto memory_area_iterator::operator->() const -> value_type * { return ptr; } auto memory_area_iterator::operator++(int) -> memory_area_iterator { - ++(*this); - return *this; + memory_area_iterator old_value = *this; + ++ptr; + return old_value; } auto memory_area_iterator::operator++() -> memory_area_iterator & @@ -21,4 +26,48 @@ namespace teachos::arch::memory::multiboot ++ptr; return *this; } + + auto memory_area_iterator::operator+=(difference_type value) -> memory_area_iterator & + { + ptr += value; + return *this; + } + + auto memory_area_iterator::operator-=(difference_type value) -> memory_area_iterator & + { + ptr -= value; + return *this; + } + + auto memory_area_iterator::operator+(difference_type value) const -> memory_area_iterator + { + return memory_area_iterator{ptr + value}; + } + + auto memory_area_iterator::operator-(difference_type value) const -> memory_area_iterator + { + return memory_area_iterator{ptr - value}; + } + + auto memory_area_iterator::operator-(const memory_area_iterator & other) const -> difference_type + { + return ptr - other.ptr; + } + + auto memory_area_iterator::operator[](difference_type index) const -> value_type & { return *(ptr + index); } + + memory_area_container::memory_area_container(memory_area * begin, std::size_t size) + : area_begin(begin) + , area_end(begin + size) + { + // Nothing to do + } + + auto memory_area_container::begin() const -> multiboot::memory_area_iterator { return area_begin; } + + auto memory_area_container::end() const -> multiboot::memory_area_iterator { return area_end; } + + auto memory_area_container::size() const -> size_type { return std::distance(begin(), end()); } + + auto memory_area_container::empty() const -> bool { return size() == 0; } } // namespace teachos::arch::memory::multiboot |