Ryujinx/Ryujinx.Graphics.Gpu/DmaPusher.cs
gdkchan b8eb6abecc
Refactor shader GPU state and memory access (#1203)
* Refactor shader GPU state and memory access

* Fix NVDEC project build

* Address PR feedback and add missing XML comments
2020-05-06 11:02:28 +10:00

316 lines
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9.5 KiB
C#

using System;
using System.Collections.Concurrent;
using System.Runtime.InteropServices;
using System.Threading;
namespace Ryujinx.Graphics.Gpu
{
/// <summary>
/// GPU DMA pusher, used to push commands to the GPU.
/// </summary>
public class DmaPusher
{
private ConcurrentQueue<CommandBuffer> _commandBufferQueue;
private enum CommandBufferType
{
Prefetch,
NoPrefetch,
}
private struct CommandBuffer
{
/// <summary>
/// The type of the command buffer.
/// </summary>
public CommandBufferType Type;
/// <summary>
/// Fetched data.
/// </summary>
public int[] Words;
/// <summary>
/// The GPFIFO entry address. (used in NoPrefetch mode)
/// </summary>
public ulong EntryAddress;
/// <summary>
/// The count of entries inside this GPFIFO entry.
/// </summary>
public uint EntryCount;
/// <summary>
/// Fetch the command buffer.
/// </summary>
public void Fetch(GpuContext context)
{
if (Words == null)
{
Words = MemoryMarshal.Cast<byte, int>(context.MemoryAccessor.GetSpan(EntryAddress, (int)EntryCount * 4)).ToArray();
}
}
/// <summary>
/// Read inside the command buffer.
/// </summary>
/// <param name="context">The GPU context</param>
/// <param name="index">The index inside the command buffer</param>
/// <returns>The value read</returns>
public int ReadAt(GpuContext context, int index)
{
return Words[index];
}
}
private CommandBuffer _currentCommandBuffer;
private int _wordsPosition;
/// <summary>
/// Internal GPFIFO state.
/// </summary>
private struct DmaState
{
public int Method;
public int SubChannel;
public int MethodCount;
public bool NonIncrementing;
public bool IncrementOnce;
public int LengthPending;
}
private DmaState _state;
private bool _ibEnable;
private GpuContext _context;
private AutoResetEvent _event;
/// <summary>
/// Creates a new instance of the GPU DMA pusher.
/// </summary>
/// <param name="context">GPU context that the pusher belongs to</param>
internal DmaPusher(GpuContext context)
{
_context = context;
_ibEnable = true;
_commandBufferQueue = new ConcurrentQueue<CommandBuffer>();
_event = new AutoResetEvent(false);
}
/// <summary>
/// Signal the pusher that there are new entries to process.
/// </summary>
public void SignalNewEntries()
{
_event.Set();
}
/// <summary>
/// Push a GPFIFO entry in the form of a prefetched command buffer.
/// It is intended to be used by nvservices to handle special cases.
/// </summary>
/// <param name="commandBuffer">The command buffer containing the prefetched commands</param>
public void PushHostCommandBuffer(int[] commandBuffer)
{
_commandBufferQueue.Enqueue(new CommandBuffer
{
Type = CommandBufferType.Prefetch,
Words = commandBuffer,
EntryAddress = ulong.MaxValue,
EntryCount = (uint)commandBuffer.Length
});
}
/// <summary>
/// Create a CommandBuffer from a GPFIFO entry.
/// </summary>
/// <param name="entry">The GPFIFO entry</param>
/// <returns>A new CommandBuffer based on the GPFIFO entry</returns>
private CommandBuffer CreateCommandBuffer(ulong entry)
{
ulong length = (entry >> 42) & 0x1fffff;
ulong startAddress = entry & 0xfffffffffc;
bool noPrefetch = (entry & (1UL << 63)) != 0;
CommandBufferType type = CommandBufferType.Prefetch;
if (noPrefetch)
{
type = CommandBufferType.NoPrefetch;
}
return new CommandBuffer
{
Type = type,
Words = null,
EntryAddress = startAddress,
EntryCount = (uint)length
};
}
/// <summary>
/// Pushes GPFIFO entries.
/// </summary>
/// <param name="entries">GPFIFO entries</param>
public void PushEntries(ReadOnlySpan<ulong> entries)
{
bool beforeBarrier = true;
foreach (ulong entry in entries)
{
CommandBuffer commandBuffer = CreateCommandBuffer(entry);
if (beforeBarrier && commandBuffer.Type == CommandBufferType.Prefetch)
{
commandBuffer.Fetch(_context);
}
if (commandBuffer.Type == CommandBufferType.NoPrefetch)
{
beforeBarrier = false;
}
_commandBufferQueue.Enqueue(commandBuffer);
}
}
/// <summary>
/// Waits until commands are pushed to the FIFO.
/// </summary>
/// <returns>True if commands were received, false if wait timed out</returns>
public bool WaitForCommands()
{
return _event.WaitOne(8);
}
/// <summary>
/// Processes commands pushed to the FIFO.
/// </summary>
public void DispatchCalls()
{
while (Step());
}
/// <summary>
/// Processes a single command on the FIFO.
/// </summary>
/// <returns>True if the FIFO still has commands to be processed, false otherwise</returns>
private bool Step()
{
if (_wordsPosition != _currentCommandBuffer.EntryCount)
{
int word = _currentCommandBuffer.ReadAt(_context, _wordsPosition++);
if (_state.LengthPending != 0)
{
_state.LengthPending = 0;
_state.MethodCount = word & 0xffffff;
}
else if (_state.MethodCount != 0)
{
CallMethod(word);
if (!_state.NonIncrementing)
{
_state.Method++;
}
if (_state.IncrementOnce)
{
_state.NonIncrementing = true;
}
_state.MethodCount--;
}
else
{
int submissionMode = (word >> 29) & 7;
switch (submissionMode)
{
case 1:
// Incrementing.
SetNonImmediateState(word);
_state.NonIncrementing = false;
_state.IncrementOnce = false;
break;
case 3:
// Non-incrementing.
SetNonImmediateState(word);
_state.NonIncrementing = true;
_state.IncrementOnce = false;
break;
case 4:
// Immediate.
_state.Method = (word >> 0) & 0x1fff;
_state.SubChannel = (word >> 13) & 7;
_state.NonIncrementing = true;
_state.IncrementOnce = false;
CallMethod((word >> 16) & 0x1fff);
break;
case 5:
// Increment-once.
SetNonImmediateState(word);
_state.NonIncrementing = false;
_state.IncrementOnce = true;
break;
}
}
}
else if (_ibEnable && _commandBufferQueue.TryDequeue(out CommandBuffer entry))
{
_currentCommandBuffer = entry;
_wordsPosition = 0;
_currentCommandBuffer.Fetch(_context);
}
else
{
return false;
}
return true;
}
/// <summary>
/// Sets current non-immediate method call state.
/// </summary>
/// <param name="word">Compressed method word</param>
private void SetNonImmediateState(int word)
{
_state.Method = (word >> 0) & 0x1fff;
_state.SubChannel = (word >> 13) & 7;
_state.MethodCount = (word >> 16) & 0x1fff;
}
/// <summary>
/// Forwards the method call to GPU engines.
/// </summary>
/// <param name="argument">Call argument</param>
private void CallMethod(int argument)
{
_context.Fifo.CallMethod(new MethodParams(
_state.Method,
argument,
_state.SubChannel,
_state.MethodCount));
}
}
}