gpu: Rewrite virtual memory manager using PageTable.

src/video_core/memory_manager.h

@@ -1,79 +1,147 @@
-// Copyright 2018 yuzu emulator team
+// Copyright 2018 yuzu emulator team
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
 #pragma once
 
-#include <array>
-#include <memory>
+#include <map>
 #include <optional>
-#include <vector>
 
 #include "common/common_types.h"
+#include "common/page_table.h"
 
 namespace Tegra {
 
+/**
+ * Represents a VMA in an address space. A VMA is a contiguous region of virtual addressing space
+ * with homogeneous attributes across its extents. In this particular implementation each VMA is
+ * also backed by a single host memory allocation.
+ */
+struct VirtualMemoryArea {
+    enum class Type : u8 {
+        Unmapped,
+        Allocated,
+        Mapped,
+    };
+
+    /// Virtual base address of the region.
+    GPUVAddr base{};
+    /// Size of the region.
+    u64 size{};
+    /// Memory area mapping type.
+    Type type{Type::Unmapped};
+    /// CPU memory mapped address corresponding to this memory area.
+    VAddr backing_addr{};
+    /// Offset into the backing_memory the mapping starts from.
+    std::size_t offset{};
+    /// Pointer backing this VMA.
+    u8* backing_memory{};
+
+    /// Tests if this area can be merged to the right with `next`.
+    bool CanBeMergedWith(const VirtualMemoryArea& next) const;
+};
+
 class MemoryManager final {
 public:
     MemoryManager();
 
     GPUVAddr AllocateSpace(u64 size, u64 align);
     GPUVAddr AllocateSpace(GPUVAddr gpu_addr, u64 size, u64 align);
-    GPUVAddr MapBufferEx(VAddr cpu_addr, u64 size);
-    GPUVAddr MapBufferEx(VAddr cpu_addr, GPUVAddr gpu_addr, u64 size);
+    GPUVAddr MapBufferEx(GPUVAddr cpu_addr, u64 size);
+    GPUVAddr MapBufferEx(GPUVAddr cpu_addr, GPUVAddr gpu_addr, u64 size);
     GPUVAddr UnmapBuffer(GPUVAddr gpu_addr, u64 size);
-    GPUVAddr GetRegionEnd(GPUVAddr region_start) const;
     std::optional<VAddr> GpuToCpuAddress(GPUVAddr gpu_addr);
 
-    static constexpr u64 PAGE_BITS = 16;
-    static constexpr u64 PAGE_SIZE = 1 << PAGE_BITS;
-    static constexpr u64 PAGE_MASK = PAGE_SIZE - 1;
+    template <typename T>
+    T Read(GPUVAddr vaddr);
 
-    u8 Read8(GPUVAddr addr);
-    u16 Read16(GPUVAddr addr);
-    u32 Read32(GPUVAddr addr);
-    u64 Read64(GPUVAddr addr);
-
-    void Write8(GPUVAddr addr, u8 data);
-    void Write16(GPUVAddr addr, u16 data);
-    void Write32(GPUVAddr addr, u32 data);
-    void Write64(GPUVAddr addr, u64 data);
+    template <typename T>
+    void Write(GPUVAddr vaddr, T data);
 
     u8* GetPointer(GPUVAddr vaddr);
 
     void ReadBlock(GPUVAddr src_addr, void* dest_buffer, std::size_t size);
     void WriteBlock(GPUVAddr dest_addr, const void* src_buffer, std::size_t size);
-    void CopyBlock(VAddr dest_addr, VAddr src_addr, std::size_t size);
+    void CopyBlock(GPUVAddr dest_addr, GPUVAddr src_addr, std::size_t size);
 
 private:
-    enum class PageStatus : u64 {
-        Unmapped = 0xFFFFFFFFFFFFFFFFULL,
-        Allocated = 0xFFFFFFFFFFFFFFFEULL,
-        Reserved = 0xFFFFFFFFFFFFFFFDULL,
-    };
+    using VMAMap = std::map<GPUVAddr, VirtualMemoryArea>;
+    using VMAHandle = VMAMap::const_iterator;
+    using VMAIter = VMAMap::iterator;
 
-    std::optional<GPUVAddr> FindFreeBlock(GPUVAddr region_start, u64 size, u64 align,
-                                          PageStatus status);
-    VAddr& PageSlot(GPUVAddr gpu_addr);
+    void MapPages(GPUVAddr base, u64 size, u8* memory, Common::PageType type,
+                  VAddr backing_addr = 0);
+    void MapMemoryRegion(GPUVAddr base, u64 size, u8* target, VAddr backing_addr);
+    void UnmapRegion(GPUVAddr base, u64 size);
 
-    static constexpr u64 MAX_ADDRESS{0x10000000000ULL};
-    static constexpr u64 PAGE_TABLE_BITS{10};
-    static constexpr u64 PAGE_TABLE_SIZE{1 << PAGE_TABLE_BITS};
-    static constexpr u64 PAGE_TABLE_MASK{PAGE_TABLE_SIZE - 1};
-    static constexpr u64 PAGE_BLOCK_BITS{14};
-    static constexpr u64 PAGE_BLOCK_SIZE{1 << PAGE_BLOCK_BITS};
-    static constexpr u64 PAGE_BLOCK_MASK{PAGE_BLOCK_SIZE - 1};
+    /// Finds the VMA in which the given address is included in, or `vma_map.end()`.
+    VMAHandle FindVMA(GPUVAddr target) const;
 
-    using PageBlock = std::array<VAddr, PAGE_BLOCK_SIZE>;
-    std::array<std::unique_ptr<PageBlock>, PAGE_TABLE_SIZE> page_table{};
+    VMAHandle AllocateMemory(GPUVAddr target, std::size_t offset, u64 size);
 
-    struct MappedRegion {
-        VAddr cpu_addr;
-        GPUVAddr gpu_addr;
-        u64 size;
-    };
+    /**
+     * Maps an unmanaged host memory pointer at a given address.
+     *
+     * @param target The guest address to start the mapping at.
+     * @param memory The memory to be mapped.
+     * @param size Size of the mapping.
+     * @param state MemoryState tag to attach to the VMA.
+     */
+    VMAHandle MapBackingMemory(GPUVAddr target, u8* memory, u64 size, VAddr backing_addr);
 
-    std::vector<MappedRegion> mapped_regions;
+    /// Unmaps a range of addresses, splitting VMAs as necessary.
+    void UnmapRange(GPUVAddr target, u64 size);
+
+    /// Converts a VMAHandle to a mutable VMAIter.
+    VMAIter StripIterConstness(const VMAHandle& iter);
+
+    /// Unmaps the given VMA.
+    VMAIter Unmap(VMAIter vma);
+
+    /**
+     * Carves a VMA of a specific size at the specified address by splitting Free VMAs while doing
+     * the appropriate error checking.
+     */
+    VMAIter CarveVMA(GPUVAddr base, u64 size);
+
+    /**
+     * Splits the edges of the given range of non-Free VMAs so that there is a VMA split at each
+     * end of the range.
+     */
+    VMAIter CarveVMARange(GPUVAddr base, u64 size);
+
+    /**
+     * Splits a VMA in two, at the specified offset.
+     * @returns the right side of the split, with the original iterator becoming the left side.
+     */
+    VMAIter SplitVMA(VMAIter vma, u64 offset_in_vma);
+
+    /**
+     * Checks for and merges the specified VMA with adjacent ones if possible.
+     * @returns the merged VMA or the original if no merging was possible.
+     */
+    VMAIter MergeAdjacent(VMAIter vma);
+
+    /// Updates the pages corresponding to this VMA so they match the VMA's attributes.
+    void UpdatePageTableForVMA(const VirtualMemoryArea& vma);
+
+    GPUVAddr FindFreeRegion(GPUVAddr region_start, u64 size, u64 align,
+                            VirtualMemoryArea::Type vma_type);
+
+private:
+    static constexpr u64 page_bits{16};
+    static constexpr u64 page_size{1 << page_bits};
+    static constexpr u64 page_mask{page_size - 1};
+
+    /// Address space in bits, this is fairly arbitrary but sufficiently large.
+    static constexpr u32 address_space_width = 39;
+    /// Start address for mapping, this is fairly arbitrary but must be non-zero.
+    static constexpr GPUVAddr address_space_base = 0x100000;
+    /// End of address space, based on address space in bits.
+    static constexpr GPUVAddr address_space_end = 1ULL << address_space_width;
+
+    Common::PageTable page_table{page_bits};
+    VMAMap vma_map;
 };
 
 } // namespace Tegra