1 files changed, 331 insertions, 17 deletions
diff --git a/src/Ryujinx.Memory/VirtualMemoryManagerBase.cs b/src/Ryujinx.Memory/VirtualMemoryManagerBase.cs
index cbec88cc..506e25f6 100644
--- a/src/Ryujinx.Memory/VirtualMemoryManagerBase.cs
+++ b/src/Ryujinx.Memory/VirtualMemoryManagerBase.cs
@@ -1,34 +1,171 @@
+using Ryujinx.Common.Memory;
 using System;
-using System.Numerics;
+using System.Buffers;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 
 namespace Ryujinx.Memory
 {
-    public abstract class VirtualMemoryManagerBase<TVirtual, TPhysical>
-        where TVirtual : IBinaryInteger<TVirtual>
-        where TPhysical : IBinaryInteger<TPhysical>
+    public abstract class VirtualMemoryManagerBase : IWritableBlock
     {
         public const int PageBits = 12;
         public const int PageSize = 1 << PageBits;
         public const int PageMask = PageSize - 1;
 
-        protected abstract TVirtual AddressSpaceSize { get; }
+        protected abstract ulong AddressSpaceSize { get; }
 
-        public virtual void Read(TVirtual va, Span<byte> data)
+        public virtual ReadOnlySequence<byte> GetReadOnlySequence(ulong va, int size, bool tracked = false)
+        {
+            if (size == 0)
+            {
+                return ReadOnlySequence<byte>.Empty;
+            }
+
+            if (tracked)
+            {
+                SignalMemoryTracking(va, (ulong)size, false);
+            }
+
+            if (IsContiguousAndMapped(va, size))
+            {
+                nuint pa = TranslateVirtualAddressUnchecked(va);
+
+                return new ReadOnlySequence<byte>(GetPhysicalAddressMemory(pa, size));
+            }
+            else
+            {
+                AssertValidAddressAndSize(va, size);
+
+                int offset = 0, segmentSize;
+
+                BytesReadOnlySequenceSegment first = null, last = null;
+
+                if ((va & PageMask) != 0)
+                {
+                    nuint pa = TranslateVirtualAddressChecked(va);
+
+                    segmentSize = Math.Min(size, PageSize - (int)(va & PageMask));
+
+                    Memory<byte> memory = GetPhysicalAddressMemory(pa, segmentSize);
+
+                    first = last = new BytesReadOnlySequenceSegment(memory);
+
+                    offset += segmentSize;
+                }
+
+                for (; offset < size; offset += segmentSize)
+                {
+                    nuint pa = TranslateVirtualAddressChecked(va + (ulong)offset);
+
+                    segmentSize = Math.Min(size - offset, PageSize);
+
+                    Memory<byte> memory = GetPhysicalAddressMemory(pa, segmentSize);
+
+                    if (first is null)
+                    {
+                        first = last = new BytesReadOnlySequenceSegment(memory);
+                    }
+                    else
+                    {
+                        if (last.IsContiguousWith(memory, out nuint contiguousStart, out int contiguousSize))
+                        {
+                            last.Replace(GetPhysicalAddressMemory(contiguousStart, contiguousSize));
+                        }
+                        else
+                        {
+                            last = last.Append(memory);
+                        }
+                    }
+                }
+
+                return new ReadOnlySequence<byte>(first, 0, last, (int)(size - last.RunningIndex));
+            }
+        }
+
+        public virtual ReadOnlySpan<byte> GetSpan(ulong va, int size, bool tracked = false)
+        {
+            if (size == 0)
+            {
+                return ReadOnlySpan<byte>.Empty;
+            }
+
+            if (tracked)
+            {
+                SignalMemoryTracking(va, (ulong)size, false);
+            }
+
+            if (IsContiguousAndMapped(va, size))
+            {
+                nuint pa = TranslateVirtualAddressUnchecked(va);
+
+                return GetPhysicalAddressSpan(pa, size);
+            }
+            else
+            {
+                Span<byte> data = new byte[size];
+
+                Read(va, data);
+
+                return data;
+            }
+        }
+
+        public virtual WritableRegion GetWritableRegion(ulong va, int size, bool tracked = false)
+        {
+            if (size == 0)
+            {
+                return new WritableRegion(null, va, Memory<byte>.Empty);
+            }
+
+            if (tracked)
+            {
+                SignalMemoryTracking(va, (ulong)size, true);
+            }
+
+            if (IsContiguousAndMapped(va, size))
+            {
+                nuint pa = TranslateVirtualAddressUnchecked(va);
+
+                return new WritableRegion(null, va, GetPhysicalAddressMemory(pa, size));
+            }
+            else
+            {
+                IMemoryOwner<byte> memoryOwner = ByteMemoryPool.Rent(size);
+
+                Read(va, memoryOwner.Memory.Span);
+
+                return new WritableRegion(this, va, memoryOwner);
+            }
+        }
+
+        public abstract bool IsMapped(ulong va);
+
+        public virtual void MapForeign(ulong va, nuint hostPointer, ulong size)
+        {
+            throw new NotSupportedException();
+        }
+
+        public virtual T Read<T>(ulong va) where T : unmanaged
+        {
+            return MemoryMarshal.Cast<byte, T>(GetSpan(va, Unsafe.SizeOf<T>()))[0];
+        }
+
+        public virtual void Read(ulong va, Span<byte> data)
         {
             if (data.Length == 0)
             {
                 return;
             }
 
-            AssertValidAddressAndSize(va, TVirtual.CreateChecked(data.Length));
+            AssertValidAddressAndSize(va, data.Length);
 
             int offset = 0, size;
 
-            if ((int.CreateTruncating(va) & PageMask) != 0)
+            if ((va & PageMask) != 0)
             {
-                TPhysical pa = TranslateVirtualAddressForRead(va);
+                nuint pa = TranslateVirtualAddressChecked(va);
 
-                size = Math.Min(data.Length, PageSize - ((int.CreateTruncating(va) & PageMask)));
+                size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
 
                 GetPhysicalAddressSpan(pa, size).CopyTo(data[..size]);
 
@@ -37,7 +174,7 @@ namespace Ryujinx.Memory
 
             for (; offset < data.Length; offset += size)
             {
-                TPhysical pa = TranslateVirtualAddressForRead(va + TVirtual.CreateChecked(offset));
+                nuint pa = TranslateVirtualAddressChecked(va + (ulong)offset);
 
                 size = Math.Min(data.Length - offset, PageSize);
 
@@ -45,13 +182,84 @@ namespace Ryujinx.Memory
             }
         }
 
+        public virtual T ReadTracked<T>(ulong va) where T : unmanaged
+        {
+            SignalMemoryTracking(va, (ulong)Unsafe.SizeOf<T>(), false);
+
+            return Read<T>(va);
+        }
+
+        public virtual void SignalMemoryTracking(ulong va, ulong size, bool write, bool precise = false, int? exemptId = null)
+        {
+            // No default implementation
+        }
+
+        public virtual void Write(ulong va, ReadOnlySpan<byte> data)
+        {
+            if (data.Length == 0)
+            {
+                return;
+            }
+
+            SignalMemoryTracking(va, (ulong)data.Length, true);
+
+            WriteImpl(va, data);
+        }
+
+        public virtual void Write<T>(ulong va, T value) where T : unmanaged
+        {
+            Write(va, MemoryMarshal.Cast<T, byte>(MemoryMarshal.CreateSpan(ref value, 1)));
+        }
+
+        public virtual void WriteUntracked(ulong va, ReadOnlySpan<byte> data)
+        {
+            if (data.Length == 0)
+            {
+                return;
+            }
+
+            WriteImpl(va, data);
+        }
+
+        public virtual bool WriteWithRedundancyCheck(ulong va, ReadOnlySpan<byte> data)
+        {
+            if (data.Length == 0)
+            {
+                return false;
+            }
+
+            if (IsContiguousAndMapped(va, data.Length))
+            {
+                SignalMemoryTracking(va, (ulong)data.Length, false);
+
+                nuint pa = TranslateVirtualAddressChecked(va);
+
+                var target = GetPhysicalAddressSpan(pa, data.Length);
+
+                bool changed = !data.SequenceEqual(target);
+
+                if (changed)
+                {
+                    data.CopyTo(target);
+                }
+
+                return changed;
+            }
+            else
+            {
+                Write(va, data);
+
+                return true;
+            }
+        }
+
         /// <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>
-        protected void AssertValidAddressAndSize(TVirtual va, TVirtual size)
+        protected void AssertValidAddressAndSize(ulong va, ulong size)
         {
             if (!ValidateAddressAndSize(va, size))
             {
@@ -59,16 +267,82 @@ namespace Ryujinx.Memory
             }
         }
 
-        protected abstract Span<byte> GetPhysicalAddressSpan(TPhysical pa, int size);
+        /// <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>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected void AssertValidAddressAndSize(ulong va, int size)
+            => AssertValidAddressAndSize(va, (ulong)size);
+
+        /// <summary>
+        /// Computes the number of pages in a virtual address range.
+        /// </summary>
+        /// <param name="va">Virtual address of the range</param>
+        /// <param name="size">Size of the range</param>
+        /// <param name="startVa">The virtual address of the beginning of the first page</param>
+        /// <remarks>This function does not differentiate between allocated and unallocated pages.</remarks>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected static int GetPagesCount(ulong va, ulong 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);
+        }
+
+        protected abstract Memory<byte> GetPhysicalAddressMemory(nuint pa, int size);
+
+        protected abstract Span<byte> GetPhysicalAddressSpan(nuint pa, int size);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected bool IsContiguous(ulong va, int size) => IsContiguous(va, (ulong)size);
+
+        protected virtual bool IsContiguous(ulong va, ulong size)
+        {
+            if (!ValidateAddress(va) || !ValidateAddressAndSize(va, size))
+            {
+                return false;
+            }
+
+            int pages = GetPagesCount(va, size, out va);
+
+            for (int page = 0; page < pages - 1; page++)
+            {
+                if (!ValidateAddress(va + PageSize))
+                {
+                    return false;
+                }
+
+                if (TranslateVirtualAddressUnchecked(va) + PageSize != TranslateVirtualAddressUnchecked(va + PageSize))
+                {
+                    return false;
+                }
+
+                va += PageSize;
+            }
+
+            return true;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected bool IsContiguousAndMapped(ulong va, int size)
+            => IsContiguous(va, size) && IsMapped(va);
 
-        protected abstract TPhysical TranslateVirtualAddressForRead(TVirtual va);
+        protected abstract nuint TranslateVirtualAddressChecked(ulong va);
+
+        protected abstract nuint TranslateVirtualAddressUnchecked(ulong va);
 
         /// <summary>
         /// Checks if the virtual address is part of the addressable space.
         /// </summary>
         /// <param name="va">Virtual address</param>
         /// <returns>True if the virtual address is part of the addressable space</returns>
-        protected bool ValidateAddress(TVirtual va)
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected bool ValidateAddress(ulong va)
         {
             return va < AddressSpaceSize;
         }
@@ -79,13 +353,53 @@ namespace Ryujinx.Memory
         /// <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>
-        protected bool ValidateAddressAndSize(TVirtual va, TVirtual size)
+        protected bool ValidateAddressAndSize(ulong va, ulong size)
         {
-            TVirtual endVa = va + size;
+            ulong endVa = va + size;
             return endVa >= va && endVa >= size && endVa <= AddressSpaceSize;
         }
 
         protected static void ThrowInvalidMemoryRegionException(string message)
             => throw new InvalidMemoryRegionException(message);
+
+        protected static void ThrowMemoryNotContiguous()
+            => throw new MemoryNotContiguousException();
+
+        protected virtual void WriteImpl(ulong va, ReadOnlySpan<byte> data)
+        {
+            AssertValidAddressAndSize(va, data.Length);
+
+            if (IsContiguousAndMapped(va, data.Length))
+            {
+                nuint pa = TranslateVirtualAddressUnchecked(va);
+
+                data.CopyTo(GetPhysicalAddressSpan(pa, data.Length));
+            }
+            else
+            {
+                int offset = 0, size;
+
+                if ((va & PageMask) != 0)
+                {
+                    nuint pa = TranslateVirtualAddressChecked(va);
+
+                    size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
+
+                    data[..size].CopyTo(GetPhysicalAddressSpan(pa, size));
+
+                    offset += size;
+                }
+
+                for (; offset < data.Length; offset += size)
+                {
+                    nuint pa = TranslateVirtualAddressChecked(va + (ulong)offset);
+
+                    size = Math.Min(data.Length - offset, PageSize);
+
+                    data.Slice(offset, size).CopyTo(GetPhysicalAddressSpan(pa, size));
+                }
+            }
+        }
+
     }
 }