1 files changed, 470 insertions, 0 deletions
diff --git a/src/Ryujinx.Memory/AddressSpaceManager.cs b/src/Ryujinx.Memory/AddressSpaceManager.cs
new file mode 100644
index 00000000..ac89fca6
--- /dev/null
+++ b/src/Ryujinx.Memory/AddressSpaceManager.cs
@@ -0,0 +1,470 @@
+using Ryujinx.Memory.Range;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Memory
+{
+    /// <summary>
+    /// Represents a address space manager.
+    /// Supports virtual memory region mapping, address translation and read/write access to mapped regions.
+    /// </summary>
+    public sealed class AddressSpaceManager : IVirtualMemoryManager, IWritableBlock
+    {
+        public const int PageBits = PageTable<nuint>.PageBits;
+        public const int PageSize = PageTable<nuint>.PageSize;
+        public const int PageMask = PageTable<nuint>.PageMask;
+
+        /// <inheritdoc/>
+        public bool Supports4KBPages => true;
+
+        /// <summary>
+        /// Address space width in bits.
+        /// </summary>
+        public int AddressSpaceBits { get; }
+
+        private readonly ulong _addressSpaceSize;
+
+        private readonly MemoryBlock _backingMemory;
+        private readonly PageTable<nuint> _pageTable;
+
+        /// <summary>
+        /// Creates a new instance of the memory manager.
+        /// </summary>
+        /// <param name="backingMemory">Physical backing memory where virtual memory will be mapped to</param>
+        /// <param name="addressSpaceSize">Size of the address space</param>
+        public AddressSpaceManager(MemoryBlock backingMemory, ulong addressSpaceSize)
+        {
+            ulong asSize = PageSize;
+            int asBits = PageBits;
+
+            while (asSize < addressSpaceSize)
+            {
+                asSize <<= 1;
+                asBits++;
+            }
+
+            AddressSpaceBits = asBits;
+            _addressSpaceSize = asSize;
+            _backingMemory = backingMemory;
+            _pageTable = new PageTable<nuint>();
+        }
+
+        /// <inheritdoc/>
+        public void Map(ulong va, ulong pa, ulong size, MemoryMapFlags flags)
+        {
+            AssertValidAddressAndSize(va, size);
+
+            while (size != 0)
+            {
+                _pageTable.Map(va, (nuint)(ulong)_backingMemory.GetPointer(pa, PageSize));
+
+                va += PageSize;
+                pa += PageSize;
+                size -= PageSize;
+            }
+        }
+
+        /// <inheritdoc/>
+        public void MapForeign(ulong va, nuint hostPointer, ulong size)
+        {
+            AssertValidAddressAndSize(va, size);
+
+            while (size != 0)
+            {
+                _pageTable.Map(va, hostPointer);
+
+                va += PageSize;
+                hostPointer += PageSize;
+                size -= PageSize;
+            }
+        }
+
+        /// <inheritdoc/>
+        public void Unmap(ulong va, ulong size)
+        {
+            AssertValidAddressAndSize(va, size);
+
+            while (size != 0)
+            {
+                _pageTable.Unmap(va);
+
+                va += PageSize;
+                size -= PageSize;
+            }
+        }
+
+        /// <inheritdoc/>
+        public T Read<T>(ulong va) where T : unmanaged
+        {
+            return MemoryMarshal.Cast<byte, T>(GetSpan(va, Unsafe.SizeOf<T>()))[0];
+        }
+
+        /// <inheritdoc/>
+        public void Read(ulong va, Span<byte> data)
+        {
+            ReadImpl(va, data);
+        }
+
+        /// <inheritdoc/>
+        public void Write<T>(ulong va, T value) where T : unmanaged
+        {
+            Write(va, MemoryMarshal.Cast<T, byte>(MemoryMarshal.CreateSpan(ref value, 1)));
+        }
+
+        /// <inheritdoc/>
+        public void Write(ulong va, ReadOnlySpan<byte> data)
+        {
+            if (data.Length == 0)
+            {
+                return;
+            }
+
+            AssertValidAddressAndSize(va, (ulong)data.Length);
+
+            if (IsContiguousAndMapped(va, data.Length))
+            {
+                data.CopyTo(GetHostSpanContiguous(va, data.Length));
+            }
+            else
+            {
+                int offset = 0, size;
+
+                if ((va & PageMask) != 0)
+                {
+                    size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
+
+                    data.Slice(0, size).CopyTo(GetHostSpanContiguous(va, size));
+
+                    offset += size;
+                }
+
+                for (; offset < data.Length; offset += size)
+                {
+                    size = Math.Min(data.Length - offset, PageSize);
+
+                    data.Slice(offset, size).CopyTo(GetHostSpanContiguous(va + (ulong)offset, size));
+                }
+            }
+        }
+
+        /// <inheritdoc/>
+        public bool WriteWithRedundancyCheck(ulong va, ReadOnlySpan<byte> data)
+        {
+            Write(va, data);
+
+            return true;
+        }
+
+        /// <inheritdoc/>
+        public ReadOnlySpan<byte> GetSpan(ulong va, int size, bool tracked = false)
+        {
+            if (size == 0)
+            {
+                return ReadOnlySpan<byte>.Empty;
+            }
+
+            if (IsContiguousAndMapped(va, size))
+            {
+                return GetHostSpanContiguous(va, size);
+            }
+            else
+            {
+                Span<byte> data = new byte[size];
+
+                ReadImpl(va, data);
+
+                return data;
+            }
+        }
+
+        /// <inheritdoc/>
+        public unsafe WritableRegion GetWritableRegion(ulong va, int size, bool tracked = false)
+        {
+            if (size == 0)
+            {
+                return new WritableRegion(null, va, Memory<byte>.Empty);
+            }
+
+            if (IsContiguousAndMapped(va, size))
+            {
+                return new WritableRegion(null, va, new NativeMemoryManager<byte>((byte*)GetHostAddress(va), size).Memory);
+            }
+            else
+            {
+                Memory<byte> memory = new byte[size];
+
+                GetSpan(va, size).CopyTo(memory.Span);
+
+                return new WritableRegion(this, va, memory);
+            }
+        }
+
+        /// <inheritdoc/>
+        public unsafe ref T GetRef<T>(ulong va) where T : unmanaged
+        {
+            if (!IsContiguous(va, Unsafe.SizeOf<T>()))
+            {
+                ThrowMemoryNotContiguous();
+            }
+
+            return ref *(T*)GetHostAddress(va);
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private int GetPagesCount(ulong va, uint size, out ulong startVa)
+        {
+            // WARNING: Always check if ulong does not overflow during the operations.
+            startVa = va & ~(ulong)PageMask;
+            ulong vaSpan = (va - startVa + size + PageMask) & ~(ulong)PageMask;
+
+            return (int)(vaSpan / PageSize);
+        }
+
+        private void ThrowMemoryNotContiguous() => throw new MemoryNotContiguousException();
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private bool IsContiguousAndMapped(ulong va, int size) => IsContiguous(va, size) && IsMapped(va);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private bool IsContiguous(ulong va, int size)
+        {
+            if (!ValidateAddress(va) || !ValidateAddressAndSize(va, (ulong)size))
+            {
+                return false;
+            }
+
+            int pages = GetPagesCount(va, (uint)size, out va);
+
+            for (int page = 0; page < pages - 1; page++)
+            {
+                if (!ValidateAddress(va + PageSize))
+                {
+                    return false;
+                }
+
+                if (GetHostAddress(va) + PageSize != GetHostAddress(va + PageSize))
+                {
+                    return false;
+                }
+
+                va += PageSize;
+            }
+
+            return true;
+        }
+
+        /// <inheritdoc/>
+        public IEnumerable<HostMemoryRange> GetHostRegions(ulong va, ulong size)
+        {
+            if (size == 0)
+            {
+                return Enumerable.Empty<HostMemoryRange>();
+            }
+
+            return GetHostRegionsImpl(va, size);
+        }
+
+        /// <inheritdoc/>
+        public IEnumerable<MemoryRange> GetPhysicalRegions(ulong va, ulong size)
+        {
+            if (size == 0)
+            {
+                return Enumerable.Empty<MemoryRange>();
+            }
+
+            var hostRegions = GetHostRegionsImpl(va, size);
+            if (hostRegions == null)
+            {
+                return null;
+            }
+
+            var regions = new MemoryRange[hostRegions.Count];
+
+            ulong backingStart = (ulong)_backingMemory.Pointer;
+            ulong backingEnd = backingStart + _backingMemory.Size;
+
+            int count = 0;
+
+            for (int i = 0; i < regions.Length; i++)
+            {
+                var hostRegion = hostRegions[i];
+
+                if ((ulong)hostRegion.Address >= backingStart && (ulong)hostRegion.Address < backingEnd)
+                {
+                    regions[count++] = new MemoryRange((ulong)hostRegion.Address - backingStart, hostRegion.Size);
+                }
+            }
+
+            if (count != regions.Length)
+            {
+                return new ArraySegment<MemoryRange>(regions, 0, count);
+            }
+
+            return regions;
+        }
+
+        private List<HostMemoryRange> GetHostRegionsImpl(ulong va, ulong size)
+        {
+            if (!ValidateAddress(va) || !ValidateAddressAndSize(va, size))
+            {
+                return null;
+            }
+
+            int pages = GetPagesCount(va, (uint)size, out va);
+
+            var regions = new List<HostMemoryRange>();
+
+            nuint regionStart = GetHostAddress(va);
+            ulong regionSize = PageSize;
+
+            for (int page = 0; page < pages - 1; page++)
+            {
+                if (!ValidateAddress(va + PageSize))
+                {
+                    return null;
+                }
+
+                nuint newHostAddress = GetHostAddress(va + PageSize);
+
+                if (GetHostAddress(va) + PageSize != newHostAddress)
+                {
+                    regions.Add(new HostMemoryRange(regionStart, regionSize));
+                    regionStart = newHostAddress;
+                    regionSize = 0;
+                }
+
+                va += PageSize;
+                regionSize += PageSize;
+            }
+
+            regions.Add(new HostMemoryRange(regionStart, regionSize));
+
+            return regions;
+        }
+
+        private void ReadImpl(ulong va, Span<byte> data)
+        {
+            if (data.Length == 0)
+            {
+                return;
+            }
+
+            AssertValidAddressAndSize(va, (ulong)data.Length);
+
+            int offset = 0, size;
+
+            if ((va & PageMask) != 0)
+            {
+                size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
+
+                GetHostSpanContiguous(va, size).CopyTo(data.Slice(0, size));
+
+                offset += size;
+            }
+
+            for (; offset < data.Length; offset += size)
+            {
+                size = Math.Min(data.Length - offset, PageSize);
+
+                GetHostSpanContiguous(va + (ulong)offset, size).CopyTo(data.Slice(offset, size));
+            }
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool IsMapped(ulong va)
+        {
+            if (!ValidateAddress(va))
+            {
+                return false;
+            }
+
+            return _pageTable.Read(va) != 0;
+        }
+
+        /// <inheritdoc/>
+        public bool IsRangeMapped(ulong va, ulong size)
+        {
+            if (size == 0UL)
+            {
+                return true;
+            }
+
+            if (!ValidateAddressAndSize(va, size))
+            {
+                return false;
+            }
+
+            int pages = GetPagesCount(va, (uint)size, out va);
+
+            for (int page = 0; page < pages; page++)
+            {
+                if (!IsMapped(va))
+                {
+                    return false;
+                }
+
+                va += PageSize;
+            }
+
+            return true;
+        }
+
+        private bool ValidateAddress(ulong va)
+        {
+            return va < _addressSpaceSize;
+        }
+
+        /// <summary>
+        /// Checks if the combination of virtual address and size is part of the addressable space.
+        /// </summary>
+        /// <param name="va">Virtual address of the range</param>
+        /// <param name="size">Size of the range in bytes</param>
+        /// <returns>True if the combination of virtual address and size is part of the addressable space</returns>
+        private bool ValidateAddressAndSize(ulong va, ulong size)
+        {
+            ulong endVa = va + size;
+            return endVa >= va && endVa >= size && endVa <= _addressSpaceSize;
+        }
+
+        /// <summary>
+        /// Ensures the combination of virtual address and size is part of the addressable space.
+        /// </summary>
+        /// <param name="va">Virtual address of the range</param>
+        /// <param name="size">Size of the range in bytes</param>
+        /// <exception cref="InvalidMemoryRegionException">Throw when the memory region specified outside the addressable space</exception>
+        private void AssertValidAddressAndSize(ulong va, ulong size)
+        {
+            if (!ValidateAddressAndSize(va, size))
+            {
+                throw new InvalidMemoryRegionException($"va=0x{va:X16}, size=0x{size:X16}");
+            }
+        }
+
+        private unsafe Span<byte> GetHostSpanContiguous(ulong va, int size)
+        {
+            return new Span<byte>((void*)GetHostAddress(va), size);
+        }
+
+        private nuint GetHostAddress(ulong va)
+        {
+            return _pageTable.Read(va) + (nuint)(va & PageMask);
+        }
+
+        /// <inheritdoc/>
+        public void TrackingReprotect(ulong va, ulong size, MemoryPermission protection)
+        {
+            throw new NotImplementedException();
+        }
+
+        /// <inheritdoc/>
+        public void SignalMemoryTracking(ulong va, ulong size, bool write, bool precise = false, int? exemptId = null)
+        {
+            // Only the ARM Memory Manager has tracking for now.
+        }
+    }
+}