rjx-mirror/Ryujinx.Cpu/MemoryManager.cs

538 lines
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C#
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using ARMeilleure.Memory;
using Ryujinx.Memory;
using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Threading;
namespace Ryujinx.Cpu
{
/// <summary>
/// Represents a CPU memory manager.
/// </summary>
public sealed class MemoryManager : IMemoryManager, IDisposable
{
public const int PageBits = 12;
public const int PageSize = 1 << PageBits;
public const int PageMask = PageSize - 1;
private const int PteSize = 8;
private readonly InvalidAccessHandler _invalidAccessHandler;
/// <summary>
/// Address space width in bits.
/// </summary>
public int AddressSpaceBits { get; }
private readonly ulong _addressSpaceSize;
private readonly MemoryBlock _backingMemory;
private readonly MemoryBlock _pageTable;
/// <summary>
/// Page table base pointer.
/// </summary>
public IntPtr PageTablePointer => _pageTable.Pointer;
/// <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>
/// <param name="invalidAccessHandler">Optional function to handle invalid memory accesses</param>
public MemoryManager(MemoryBlock backingMemory, ulong addressSpaceSize, InvalidAccessHandler invalidAccessHandler = null)
{
_invalidAccessHandler = invalidAccessHandler;
ulong asSize = PageSize;
int asBits = PageBits;
while (asSize < addressSpaceSize)
{
asSize <<= 1;
asBits++;
}
AddressSpaceBits = asBits;
_addressSpaceSize = asSize;
_backingMemory = backingMemory;
_pageTable = new MemoryBlock((asSize / PageSize) * PteSize);
}
/// <summary>
/// Maps a virtual memory range into a physical memory range.
/// </summary>
/// <remarks>
/// Addresses and size must be page aligned.
/// </remarks>
/// <param name="va">Virtual memory address</param>
/// <param name="pa">Physical memory address</param>
/// <param name="size">Size to be mapped</param>
public void Map(ulong va, ulong pa, ulong size)
{
while (size != 0)
{
_pageTable.Write((va / PageSize) * PteSize, PaToPte(pa));
va += PageSize;
pa += PageSize;
size -= PageSize;
}
}
/// <summary>
/// Unmaps a previously mapped range of virtual memory.
/// </summary>
/// <param name="va">Virtual address of the range to be unmapped</param>
/// <param name="size">Size of the range to be unmapped</param>
public void Unmap(ulong va, ulong size)
{
while (size != 0)
{
_pageTable.Write((va / PageSize) * PteSize, 0UL);
va += PageSize;
size -= PageSize;
}
}
/// <summary>
/// Reads data from CPU mapped memory.
/// </summary>
/// <typeparam name="T">Type of the data being read</typeparam>
/// <param name="va">Virtual address of the data in memory</param>
/// <returns>The data</returns>
/// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
public T Read<T>(ulong va) where T : unmanaged
{
return MemoryMarshal.Cast<byte, T>(GetSpan(va, Unsafe.SizeOf<T>()))[0];
}
/// <summary>
/// Reads data from CPU mapped memory.
/// </summary>
/// <param name="va">Virtual address of the data in memory</param>
/// <param name="data">Span to store the data being read into</param>
/// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
public void Read(ulong va, Span<byte> data)
{
ReadImpl(va, data);
}
/// <summary>
/// Writes data to CPU mapped memory.
/// </summary>
/// <typeparam name="T">Type of the data being written</typeparam>
/// <param name="va">Virtual address to write the data into</param>
/// <param name="value">Data to be written</param>
/// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
public void Write<T>(ulong va, T value) where T : unmanaged
{
Write(va, MemoryMarshal.Cast<T, byte>(MemoryMarshal.CreateSpan(ref value, 1)));
}
/// <summary>
/// Writes data to CPU mapped memory.
/// </summary>
/// <param name="va">Virtual address to write the data into</param>
/// <param name="data">Data to be written</param>
/// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
public void Write(ulong va, ReadOnlySpan<byte> data)
{
if (data.Length == 0)
{
return;
}
try
{
MarkRegionAsModified(va, (ulong)data.Length);
if (IsContiguousAndMapped(va, data.Length))
{
data.CopyTo(_backingMemory.GetSpan(GetPhysicalAddressInternal(va), data.Length));
}
else
{
int offset = 0, size;
if ((va & PageMask) != 0)
{
ulong pa = GetPhysicalAddressInternal(va);
size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
data.Slice(0, size).CopyTo(_backingMemory.GetSpan(pa, size));
offset += size;
}
for (; offset < data.Length; offset += size)
{
ulong pa = GetPhysicalAddressInternal(va + (ulong)offset);
size = Math.Min(data.Length - offset, PageSize);
data.Slice(offset, size).CopyTo(_backingMemory.GetSpan(pa, size));
}
}
}
catch (InvalidMemoryRegionException)
{
if (_invalidAccessHandler == null || !_invalidAccessHandler(va))
{
throw;
}
}
}
/// <summary>
/// Gets a read-only span of data from CPU mapped memory.
/// </summary>
/// <remarks>
/// This may perform a allocation if the data is not contiguous in memory.
/// For this reason, the span is read-only, you can't modify the data.
/// </remarks>
/// <param name="va">Virtual address of the data</param>
/// <param name="size">Size of the data</param>
/// <returns>A read-only span of the data</returns>
/// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
public ReadOnlySpan<byte> GetSpan(ulong va, int size)
{
if (size == 0)
{
return ReadOnlySpan<byte>.Empty;
}
if (IsContiguousAndMapped(va, size))
{
return _backingMemory.GetSpan(GetPhysicalAddressInternal(va), size);
}
else
{
Span<byte> data = new byte[size];
ReadImpl(va, data);
return data;
}
}
/// <summary>
/// Gets a region of memory that can be written to.
/// </summary>
/// <remarks>
/// If the requested region is not contiguous in physical memory,
/// this will perform an allocation, and flush the data (writing it
/// back to guest memory) on disposal.
/// </remarks>
/// <param name="va">Virtual address of the data</param>
/// <param name="size">Size of the data</param>
/// <returns>A writable region of memory containing the data</returns>
/// <exception cref="InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
public WritableRegion GetWritableRegion(ulong va, int size)
{
if (size == 0)
{
return new WritableRegion(null, va, Memory<byte>.Empty);
}
if (IsContiguousAndMapped(va, size))
{
return new WritableRegion(null, va, _backingMemory.GetMemory(GetPhysicalAddressInternal(va), size));
}
else
{
Memory<byte> memory = new byte[size];
GetSpan(va, size).CopyTo(memory.Span);
return new WritableRegion(this, va, memory);
}
}
/// <summary>
/// Gets a reference for the given type at the specified virtual memory address.
/// </summary>
/// <remarks>
/// The data must be located at a contiguous memory region.
/// </remarks>
/// <typeparam name="T">Type of the data to get the reference</typeparam>
/// <param name="va">Virtual address of the data</param>
/// <returns>A reference to the data in memory</returns>
/// <exception cref="MemoryNotContiguousException">Throw if the specified memory region is not contiguous in physical memory</exception>
public ref T GetRef<T>(ulong va) where T : unmanaged
{
if (!IsContiguous(va, Unsafe.SizeOf<T>()))
{
ThrowMemoryNotContiguous();
}
MarkRegionAsModified(va, (ulong)Unsafe.SizeOf<T>());
return ref _backingMemory.GetRef<T>(GetPhysicalAddressInternal(va));
}
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))
{
return false;
}
ulong endVa = (va + (ulong)size + PageMask) & ~(ulong)PageMask;
va &= ~(ulong)PageMask;
int pages = (int)((endVa - va) / PageSize);
for (int page = 0; page < pages - 1; page++)
{
if (!ValidateAddress(va + PageSize))
{
return false;
}
if (GetPhysicalAddressInternal(va) + PageSize != GetPhysicalAddressInternal(va + PageSize))
{
return false;
}
va += PageSize;
}
return true;
}
private void ReadImpl(ulong va, Span<byte> data)
{
if (data.Length == 0)
{
return;
}
try
{
int offset = 0, size;
if ((va & PageMask) != 0)
{
ulong pa = GetPhysicalAddressInternal(va);
size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
_backingMemory.GetSpan(pa, size).CopyTo(data.Slice(0, size));
offset += size;
}
for (; offset < data.Length; offset += size)
{
ulong pa = GetPhysicalAddressInternal(va + (ulong)offset);
size = Math.Min(data.Length - offset, PageSize);
_backingMemory.GetSpan(pa, size).CopyTo(data.Slice(offset, size));
}
}
catch (InvalidMemoryRegionException)
{
if (_invalidAccessHandler == null || !_invalidAccessHandler(va))
{
throw;
}
}
}
/// <summary>
/// Checks if a specified virtual memory region has been modified by the CPU since the last call.
/// </summary>
/// <param name="va">Virtual address of the region</param>
/// <param name="size">Size of the region</param>
/// <param name="id">Resource identifier number (maximum is 15)</param>
/// <param name="modifiedRanges">Optional array where the modified ranges should be written</param>
/// <returns>The number of modified ranges</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public int QueryModified(ulong va, ulong size, int id, (ulong, ulong)[] modifiedRanges = null)
{
if (!ValidateAddress(va))
{
return 0;
}
ulong maxSize = _addressSpaceSize - va;
if (size > maxSize)
{
size = maxSize;
}
// We need to ensure that the tagged pointer value is negative,
// JIT generated code checks that to take the slow paths and call the MemoryManager Read/Write methods.
long tag = (0x8000L | (1L << id)) << 48;
ulong endVa = (va + size + PageMask) & ~(ulong)PageMask;
va &= ~(ulong)PageMask;
ulong rgStart = va;
ulong rgSize = 0;
int rangeIndex = 0;
for (; va < endVa; va += PageSize)
{
while (true)
{
ref long pte = ref _pageTable.GetRef<long>((va >> PageBits) * PteSize);
long pteValue = pte;
// If the PTE value is 0, that means that the page is unmapped.
// We behave as if the page was not modified, since modifying a page
// that is not even mapped is impossible.
if ((pteValue & tag) == tag || pteValue == 0)
{
if (rgSize != 0)
{
if (modifiedRanges != null && rangeIndex < modifiedRanges.Length)
{
modifiedRanges[rangeIndex] = (rgStart, rgSize);
}
rangeIndex++;
rgSize = 0;
}
break;
}
else
{
if (Interlocked.CompareExchange(ref pte, pteValue | tag, pteValue) == pteValue)
{
if (rgSize == 0)
{
rgStart = va;
}
rgSize += PageSize;
break;
}
}
}
}
if (rgSize != 0)
{
if (modifiedRanges != null && rangeIndex < modifiedRanges.Length)
{
modifiedRanges[rangeIndex] = (rgStart, rgSize);
}
rangeIndex++;
}
return rangeIndex;
}
/// <summary>
/// Checks if the page at a given CPU virtual address.
/// </summary>
/// <param name="va">Virtual address to check</param>
/// <returns>True if the address is mapped, false otherwise</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public bool IsMapped(ulong va)
{
if (!ValidateAddress(va))
{
return false;
}
return _pageTable.Read<ulong>((va / PageSize) * PteSize) != 0;
}
private bool ValidateAddress(ulong va)
{
return va < _addressSpaceSize;
}
/// <summary>
/// Performs address translation of the address inside a CPU mapped memory range.
/// </summary>
/// <remarks>
/// If the address is invalid or unmapped, -1 will be returned.
/// </remarks>
/// <param name="va">Virtual address to be translated</param>
/// <returns>The physical address</returns>
public ulong GetPhysicalAddress(ulong va)
{
// We return -1L if the virtual address is invalid or unmapped.
if (!ValidateAddress(va) || !IsMapped(va))
{
return ulong.MaxValue;
}
return GetPhysicalAddressInternal(va);
}
private ulong GetPhysicalAddressInternal(ulong va)
{
return PteToPa(_pageTable.Read<ulong>((va / PageSize) * PteSize) & ~(0xffffUL << 48)) + (va & PageMask);
}
/// <summary>
/// Marks a region of memory as modified by the CPU.
/// </summary>
/// <param name="va">Virtual address of the region</param>
/// <param name="size">Size of the region</param>
public void MarkRegionAsModified(ulong va, ulong size)
{
ulong endVa = (va + size + PageMask) & ~(ulong)PageMask;
while (va < endVa)
{
ref long pageRef = ref _pageTable.GetRef<long>((va >> PageBits) * PteSize);
long pte;
do
{
pte = Volatile.Read(ref pageRef);
if (pte >= 0)
{
break;
}
}
while (Interlocked.CompareExchange(ref pageRef, pte & ~(0xffffL << 48), pte) != pte);
va += PageSize;
}
}
private ulong PaToPte(ulong pa)
{
return (ulong)_backingMemory.GetPointer(pa, PageSize).ToInt64();
}
private ulong PteToPa(ulong pte)
{
return (ulong)((long)pte - _backingMemory.Pointer.ToInt64());
}
/// <summary>
/// Disposes of resources used by the memory manager.
/// </summary>
public void Dispose() => _pageTable.Dispose();
}
}