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-rw-r--r--src/common/address_space.h150
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diff --git a/src/common/address_space.h b/src/common/address_space.h
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+// SPDX-FileCopyrightText: 2021 Skyline Team and Contributors
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <concepts>
+#include <functional>
+#include <mutex>
+#include <vector>
+
+#include "common/common_types.h"
+
+namespace Common {
+template <typename VaType, size_t AddressSpaceBits>
+concept AddressSpaceValid = std::is_unsigned_v<VaType> && sizeof(VaType) * 8 >= AddressSpaceBits;
+
+struct EmptyStruct {};
+
+/**
+ * @brief FlatAddressSpaceMap provides a generic VA->PA mapping implementation using a sorted vector
+ */
+template <typename VaType, VaType UnmappedVa, typename PaType, PaType UnmappedPa,
+ bool PaContigSplit, size_t AddressSpaceBits, typename ExtraBlockInfo = EmptyStruct>
+requires AddressSpaceValid<VaType, AddressSpaceBits>
+class FlatAddressSpaceMap {
+public:
+ /// The maximum VA that this AS can technically reach
+ static constexpr VaType VaMaximum{(1ULL << (AddressSpaceBits - 1)) +
+ ((1ULL << (AddressSpaceBits - 1)) - 1)};
+
+ explicit FlatAddressSpaceMap(VaType va_limit,
+ std::function<void(VaType, VaType)> unmap_callback = {});
+
+ FlatAddressSpaceMap() = default;
+
+ void Map(VaType virt, PaType phys, VaType size, ExtraBlockInfo extra_info = {}) {
+ std::scoped_lock lock(block_mutex);
+ MapLocked(virt, phys, size, extra_info);
+ }
+
+ void Unmap(VaType virt, VaType size) {
+ std::scoped_lock lock(block_mutex);
+ UnmapLocked(virt, size);
+ }
+
+ VaType GetVALimit() const {
+ return va_limit;
+ }
+
+protected:
+ /**
+ * @brief Represents a block of memory in the AS, the physical mapping is contiguous until
+ * another block with a different phys address is hit
+ */
+ struct Block {
+ /// VA of the block
+ VaType virt{UnmappedVa};
+ /// PA of the block, will increase 1-1 with VA until a new block is encountered
+ PaType phys{UnmappedPa};
+ [[no_unique_address]] ExtraBlockInfo extra_info;
+
+ Block() = default;
+
+ Block(VaType virt_, PaType phys_, ExtraBlockInfo extra_info_)
+ : virt(virt_), phys(phys_), extra_info(extra_info_) {}
+
+ bool Valid() const {
+ return virt != UnmappedVa;
+ }
+
+ bool Mapped() const {
+ return phys != UnmappedPa;
+ }
+
+ bool Unmapped() const {
+ return phys == UnmappedPa;
+ }
+
+ bool operator<(const VaType& p_virt) const {
+ return virt < p_virt;
+ }
+ };
+
+ /**
+ * @brief Maps a PA range into the given AS region
+ * @note block_mutex MUST be locked when calling this
+ */
+ void MapLocked(VaType virt, PaType phys, VaType size, ExtraBlockInfo extra_info);
+
+ /**
+ * @brief Unmaps the given range and merges it with other unmapped regions
+ * @note block_mutex MUST be locked when calling this
+ */
+ void UnmapLocked(VaType virt, VaType size);
+
+ std::mutex block_mutex;
+ std::vector<Block> blocks{Block{}};
+
+ /// a soft limit on the maximum VA of the AS
+ VaType va_limit{VaMaximum};
+
+private:
+ /// Callback called when the mappings in an region have changed
+ std::function<void(VaType, VaType)> unmap_callback{};
+};
+
+/**
+ * @brief FlatMemoryManager specialises FlatAddressSpaceMap to work as an allocator, with an
+ * initial, fast linear pass and a subsequent slower pass that iterates until it finds a free block
+ */
+template <typename VaType, VaType UnmappedVa, size_t AddressSpaceBits>
+requires AddressSpaceValid<VaType, AddressSpaceBits>
+class FlatAllocator
+ : public FlatAddressSpaceMap<VaType, UnmappedVa, bool, false, false, AddressSpaceBits> {
+private:
+ using Base = FlatAddressSpaceMap<VaType, UnmappedVa, bool, false, false, AddressSpaceBits>;
+
+public:
+ explicit FlatAllocator(VaType virt_start, VaType va_limit = Base::VaMaximum);
+
+ /**
+ * @brief Allocates a region in the AS of the given size and returns its address
+ */
+ VaType Allocate(VaType size);
+
+ /**
+ * @brief Marks the given region in the AS as allocated
+ */
+ void AllocateFixed(VaType virt, VaType size);
+
+ /**
+ * @brief Frees an AS region so it can be used again
+ */
+ void Free(VaType virt, VaType size);
+
+ VaType GetVAStart() const {
+ return virt_start;
+ }
+
+private:
+ /// The base VA of the allocator, no allocations will be below this
+ VaType virt_start;
+
+ /**
+ * The end address for the initial linear allocation pass
+ * Once this reaches the AS limit the slower allocation path will be used
+ */
+ VaType current_linear_alloc_end;
+};
+} // namespace Common