1 files changed, 193 insertions, 0 deletions
diff --git a/src/core/hle/kernel/k_page_heap.h b/src/core/hle/kernel/k_page_heap.h
new file mode 100644
index 000000000..de5d6a189
--- /dev/null
+++ b/src/core/hle/kernel/k_page_heap.h
@@ -0,0 +1,193 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include <bit>
+#include <vector>
+
+#include "common/alignment.h"
+#include "common/assert.h"
+#include "common/common_funcs.h"
+#include "common/common_types.h"
+#include "core/hle/kernel/k_page_bitmap.h"
+#include "core/hle/kernel/memory_types.h"
+
+namespace Kernel {
+
+class KPageHeap final : NonCopyable {
+public:
+    static constexpr s32 GetAlignedBlockIndex(std::size_t num_pages, std::size_t align_pages) {
+        const auto target_pages{std::max(num_pages, align_pages)};
+        for (std::size_t i = 0; i < NumMemoryBlockPageShifts; i++) {
+            if (target_pages <=
+                (static_cast<std::size_t>(1) << MemoryBlockPageShifts[i]) / PageSize) {
+                return static_cast<s32>(i);
+            }
+        }
+        return -1;
+    }
+
+    static constexpr s32 GetBlockIndex(std::size_t num_pages) {
+        for (s32 i{static_cast<s32>(NumMemoryBlockPageShifts) - 1}; i >= 0; i--) {
+            if (num_pages >= (static_cast<std::size_t>(1) << MemoryBlockPageShifts[i]) / PageSize) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    static constexpr std::size_t GetBlockSize(std::size_t index) {
+        return static_cast<std::size_t>(1) << MemoryBlockPageShifts[index];
+    }
+
+    static constexpr std::size_t GetBlockNumPages(std::size_t index) {
+        return GetBlockSize(index) / PageSize;
+    }
+
+private:
+    static constexpr std::size_t NumMemoryBlockPageShifts{7};
+    static constexpr std::array<std::size_t, NumMemoryBlockPageShifts> MemoryBlockPageShifts{
+        0xC, 0x10, 0x15, 0x16, 0x19, 0x1D, 0x1E,
+    };
+
+    class Block final : NonCopyable {
+    private:
+        KPageBitmap bitmap;
+        VAddr heap_address{};
+        uintptr_t end_offset{};
+        std::size_t block_shift{};
+        std::size_t next_block_shift{};
+
+    public:
+        Block() = default;
+
+        constexpr std::size_t GetShift() const {
+            return block_shift;
+        }
+        constexpr std::size_t GetNextShift() const {
+            return next_block_shift;
+        }
+        constexpr std::size_t GetSize() const {
+            return static_cast<std::size_t>(1) << GetShift();
+        }
+        constexpr std::size_t GetNumPages() const {
+            return GetSize() / PageSize;
+        }
+        constexpr std::size_t GetNumFreeBlocks() const {
+            return bitmap.GetNumBits();
+        }
+        constexpr std::size_t GetNumFreePages() const {
+            return GetNumFreeBlocks() * GetNumPages();
+        }
+
+        u64* Initialize(VAddr addr, std::size_t size, std::size_t bs, std::size_t nbs,
+                        u64* bit_storage) {
+            // Set shifts
+            block_shift = bs;
+            next_block_shift = nbs;
+
+            // Align up the address
+            VAddr end{addr + size};
+            const auto align{(next_block_shift != 0) ? (1ULL << next_block_shift)
+                                                     : (1ULL << block_shift)};
+            addr = Common::AlignDown((addr), align);
+            end = Common::AlignUp((end), align);
+
+            heap_address = addr;
+            end_offset = (end - addr) / (1ULL << block_shift);
+            return bitmap.Initialize(bit_storage, end_offset);
+        }
+
+        VAddr PushBlock(VAddr address) {
+            // Set the bit for the free block
+            std::size_t offset{(address - heap_address) >> GetShift()};
+            bitmap.SetBit(offset);
+
+            // If we have a next shift, try to clear the blocks below and return the address
+            if (GetNextShift()) {
+                const auto diff{1ULL << (GetNextShift() - GetShift())};
+                offset = Common::AlignDown(offset, diff);
+                if (bitmap.ClearRange(offset, diff)) {
+                    return heap_address + (offset << GetShift());
+                }
+            }
+
+            // We couldn't coalesce, or we're already as big as possible
+            return 0;
+        }
+
+        VAddr PopBlock(bool random) {
+            // Find a free block
+            const s64 soffset{bitmap.FindFreeBlock(random)};
+            if (soffset < 0) {
+                return 0;
+            }
+            const auto offset{static_cast<std::size_t>(soffset)};
+
+            // Update our tracking and return it
+            bitmap.ClearBit(offset);
+            return heap_address + (offset << GetShift());
+        }
+
+    public:
+        static constexpr std::size_t CalculateManagementOverheadSize(std::size_t region_size,
+                                                                     std::size_t cur_block_shift,
+                                                                     std::size_t next_block_shift) {
+            const auto cur_block_size{(1ULL << cur_block_shift)};
+            const auto next_block_size{(1ULL << next_block_shift)};
+            const auto align{(next_block_shift != 0) ? next_block_size : cur_block_size};
+            return KPageBitmap::CalculateManagementOverheadSize(
+                (align * 2 + Common::AlignUp(region_size, align)) / cur_block_size);
+        }
+    };
+
+public:
+    KPageHeap() = default;
+
+    constexpr VAddr GetAddress() const {
+        return heap_address;
+    }
+    constexpr std::size_t GetSize() const {
+        return heap_size;
+    }
+    constexpr VAddr GetEndAddress() const {
+        return GetAddress() + GetSize();
+    }
+    constexpr std::size_t GetPageOffset(VAddr block) const {
+        return (block - GetAddress()) / PageSize;
+    }
+
+    void Initialize(VAddr heap_address, std::size_t heap_size, std::size_t metadata_size);
+    VAddr AllocateBlock(s32 index, bool random);
+    void Free(VAddr addr, std::size_t num_pages);
+
+    void UpdateUsedSize() {
+        used_size = heap_size - (GetNumFreePages() * PageSize);
+    }
+
+    static std::size_t CalculateManagementOverheadSize(std::size_t region_size);
+
+private:
+    constexpr std::size_t GetNumFreePages() const {
+        std::size_t num_free{};
+
+        for (const auto& block : blocks) {
+            num_free += block.GetNumFreePages();
+        }
+
+        return num_free;
+    }
+
+    void FreeBlock(VAddr block, s32 index);
+
+    VAddr heap_address{};
+    std::size_t heap_size{};
+    std::size_t used_size{};
+    std::array<Block, NumMemoryBlockPageShifts> blocks{};
+    std::vector<u64> metadata;
+};
+
+} // namespace Kernel