Improve kernel IPC related syscalls (#1379)

* Implement session count decrement when the handle is closed

* Remove unused field

* Implement SendSyncRequestWithUserBuffer, SendAsyncRequestWithUserBuffer and ReplyAndReceiveWithUserBuffer syscalls

* Nits

* Fix swapped copy dst/src

* Add missing pointer buffer descriptor write on reply

* Fix IPC unaligned buffer copy and restoring client attributes on reply

* Oops

* Fix SetIpcMappingPermission

* Fix unaligned copy bugs

* Free memory used for temporary IPC buffers

6 files changed, 117 insertions, 66 deletions

diff --git a/Ryujinx.HLE/HOS/Kernel/Ipc/KBufferDescriptorTable.cs b/Ryujinx.HLE/HOS/Kernel/Ipc/KBufferDescriptorTable.cs
index 6aa211dd..0986adf7 100644
--- a/Ryujinx.HLE/HOS/Kernel/Ipc/KBufferDescriptorTable.cs
+++ b/Ryujinx.HLE/HOS/Kernel/Ipc/KBufferDescriptorTable.cs
@@ -115,19 +115,20 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
 
                 ulong clientEndAddrTruncated = BitUtils.AlignDown(clientEndAddr, KMemoryManager.PageSize);
                 ulong clientEndAddrRounded   = BitUtils.AlignUp  (clientEndAddr, KMemoryManager.PageSize);
-                ulong serverEndAddrTruncated = BitUtils.AlignDown(clientEndAddr, KMemoryManager.PageSize);
+                ulong serverEndAddrTruncated = BitUtils.AlignDown(serverEndAddr, KMemoryManager.PageSize);
 
-                if (clientEndAddrTruncated < clientAddrRounded)
+                if (clientEndAddrTruncated < clientEndAddrRounded &&
+                    (clientAddrTruncated == clientAddrRounded || clientAddrTruncated < clientEndAddrTruncated))
                 {
-                    KernelResult result = memoryManager.CopyDataToCurrentProcess(
+                    KernelResult result = memoryManager.CopyDataFromCurrentProcess(
                         clientEndAddrTruncated,
                         clientEndAddr - clientEndAddrTruncated,
-                        serverEndAddrTruncated,
                         stateMask,
                         stateMask,
                         MemoryPermission.ReadAndWrite,
                         attributeMask,
-                        MemoryAttribute.None);
+                        MemoryAttribute.None,
+                        serverEndAddrTruncated);
 
                     if (result != KernelResult.Success)
                     {
diff --git a/Ryujinx.HLE/HOS/Kernel/Ipc/KClientPort.cs b/Ryujinx.HLE/HOS/Kernel/Ipc/KClientPort.cs
index 9c542ca0..8d6669cf 100644
--- a/Ryujinx.HLE/HOS/Kernel/Ipc/KClientPort.cs
+++ b/Ryujinx.HLE/HOS/Kernel/Ipc/KClientPort.cs
@@ -1,21 +1,19 @@
 using Ryujinx.HLE.HOS.Kernel.Common;
 using Ryujinx.HLE.HOS.Kernel.Process;
 using Ryujinx.HLE.HOS.Services;
+using System.Threading;
 
 namespace Ryujinx.HLE.HOS.Kernel.Ipc
 {
     class KClientPort : KSynchronizationObject
     {
         private int _sessionsCount;
-        private int _currentCapacity;
         private readonly int _maxSessions;
 
         private readonly KPort _parent;
 
         public bool IsLight => _parent.IsLight;
 
-        private readonly object _countIncLock;
-
         // TODO: Remove that, we need it for now to allow HLE
         // SM implementation to work with the new IPC system.
         public IpcService Service { get; set; }
@@ -24,8 +22,6 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
         {
             _maxSessions = maxSessions;
             _parent      = parent;
-
-            _countIncLock = new object();
         }
 
         public KernelResult Connect(out KClientSession clientSession)
@@ -40,26 +36,14 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
                 return KernelResult.ResLimitExceeded;
             }
 
-            lock (_countIncLock)
+            if (!IncrementSessionsCount())
             {
-                if (_sessionsCount < _maxSessions)
-                {
-                    _sessionsCount++;
-                }
-                else
-                {
-                    currentProcess.ResourceLimit?.Release(LimitableResource.Session, 1);
-
-                    return KernelResult.SessionCountExceeded;
-                }
+                currentProcess.ResourceLimit?.Release(LimitableResource.Session, 1);
 
-                if (_currentCapacity < _sessionsCount)
-                {
-                    _currentCapacity = _sessionsCount;
-                }
+                return KernelResult.SessionCountExceeded;
             }
 
-            KSession session = new KSession(KernelContext);
+            KSession session = new KSession(KernelContext, this);
 
             if (Service != null)
             {
@@ -93,18 +77,11 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
                 return KernelResult.ResLimitExceeded;
             }
 
-            lock (_countIncLock)
+            if (!IncrementSessionsCount())
             {
-                if (_sessionsCount < _maxSessions)
-                {
-                    _sessionsCount++;
-                }
-                else
-                {
-                    currentProcess.ResourceLimit?.Release(LimitableResource.Session, 1);
+                currentProcess.ResourceLimit?.Release(LimitableResource.Session, 1);
 
-                    return KernelResult.SessionCountExceeded;
-                }
+                return KernelResult.SessionCountExceeded;
             }
 
             KLightSession session = new KLightSession(KernelContext);
@@ -124,6 +101,43 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
             return result;
         }
 
+        private bool IncrementSessionsCount()
+        {
+            while (true)
+            {
+                int currentCount = _sessionsCount;
+
+                if (currentCount < _maxSessions)
+                {
+                    if (Interlocked.CompareExchange(ref _sessionsCount, currentCount + 1, currentCount) == currentCount)
+                    {
+                        return true;
+                    }
+                }
+                else
+                {
+                    return false;
+                }
+            }
+        }
+
+        public void Disconnect()
+        {
+            KernelContext.CriticalSection.Enter();
+
+            SignalIfMaximumReached(Interlocked.Decrement(ref _sessionsCount));
+
+            KernelContext.CriticalSection.Leave();
+        }
+
+        private void SignalIfMaximumReached(int value)
+        {
+            if (value == _maxSessions)
+            {
+                Signal();
+            }
+        }
+
         public new static KernelResult RemoveName(KernelContext context, string name)
         {
             KAutoObject foundObj = FindNamedObject(context, name);
diff --git a/Ryujinx.HLE/HOS/Kernel/Ipc/KClientSession.cs b/Ryujinx.HLE/HOS/Kernel/Ipc/KClientSession.cs
index b99dd1cb..262058d9 100644
--- a/Ryujinx.HLE/HOS/Kernel/Ipc/KClientSession.cs
+++ b/Ryujinx.HLE/HOS/Kernel/Ipc/KClientSession.cs
@@ -13,18 +13,22 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
 
         public ChannelState State { get; set; }
 
+        public KClientPort ParentPort { get; }
+
         // TODO: Remove that, we need it for now to allow HLE
         // services implementation to work with the new IPC system.
         public IpcService Service { get; set; }
 
-        public KClientSession(KernelContext context, KSession parent) : base(context)
+        public KClientSession(KernelContext context, KSession parent, KClientPort parentPort) : base(context)
         {
-            _parent = parent;
+            _parent    = parent;
+            ParentPort = parentPort;
+
+            parentPort?.IncrementReferenceCount();
 
             State = ChannelState.Open;
 
             CreatorProcess = context.Scheduler.GetCurrentProcess();
-
             CreatorProcess.IncrementReferenceCount();
         }
 
@@ -51,6 +55,30 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
             return result;
         }
 
+        public KernelResult SendAsyncRequest(KWritableEvent asyncEvent, ulong customCmdBuffAddr = 0, ulong customCmdBuffSize = 0)
+        {
+            KThread currentThread = KernelContext.Scheduler.GetCurrentThread();
+
+            KSessionRequest request = new KSessionRequest(currentThread, customCmdBuffAddr, customCmdBuffSize, asyncEvent);
+
+            KernelContext.CriticalSection.Enter();
+
+            KernelResult result = _parent.ServerSession.EnqueueRequest(request);
+
+            KernelContext.CriticalSection.Leave();
+
+            return result;
+        }
+
+        public void DisconnectFromPort()
+        {
+            if (ParentPort != null)
+            {
+                ParentPort.Disconnect();
+                ParentPort.DecrementReferenceCount();
+            }
+        }
+
         protected override void Destroy()
         {
             _parent.DisconnectClient();
diff --git a/Ryujinx.HLE/HOS/Kernel/Ipc/KServerSession.cs b/Ryujinx.HLE/HOS/Kernel/Ipc/KServerSession.cs
index 70b54d05..48669832 100644
--- a/Ryujinx.HLE/HOS/Kernel/Ipc/KServerSession.cs
+++ b/Ryujinx.HLE/HOS/Kernel/Ipc/KServerSession.cs
@@ -633,7 +633,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
             {
                 CloseAllHandles(clientMsg, serverHeader, clientProcess);
 
-                CancelRequest(request, clientResult);
+                FinishRequest(request, clientResult);
             }
 
             if (clientHeader.ReceiveListType < 2 &&
@@ -770,6 +770,8 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
 
                 PointerBufferDesc descriptor = new PointerBufferDesc(pointerDesc);
 
+                ulong recvListBufferAddress = 0;
+
                 if (descriptor.BufferSize != 0)
                 {
                     clientResult = GetReceiveListAddress(
@@ -778,8 +780,8 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
                         clientHeader.ReceiveListType,
                         serverHeader.MessageSizeInWords,
                         receiveList,
-                        ref       recvListDstOffset,
-                        out ulong recvListBufferAddress);
+                        ref recvListDstOffset,
+                        out recvListBufferAddress);
 
                     if (clientResult != KernelResult.Success)
                     {
@@ -806,6 +808,17 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
                     }
                 }
 
+                ulong dstDescAddress = clientMsg.DramAddress + offset * 4;
+
+                ulong clientPointerDesc =
+                    (recvListBufferAddress << 32) |
+                    ((recvListBufferAddress >> 20) & 0xf000) |
+                    ((recvListBufferAddress >> 30) & 0xffc0);
+
+                clientPointerDesc |= pointerDesc & 0xffff000f;
+
+                KernelContext.Memory.Write(dstDescAddress + 0, clientPointerDesc);
+
                 offset += 2;
             }
 
@@ -860,16 +873,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
             }
 
             // Unmap buffers from server.
-            clientResult = request.BufferDescriptorTable.UnmapServerBuffers(serverProcess.MemoryManager);
-
-            if (clientResult != KernelResult.Success)
-            {
-                CleanUpForError();
-
-                return serverResult;
-            }
-
-            WakeClientThread(request, clientResult);
+            FinishRequest(request, clientResult);
 
             return serverResult;
         }
@@ -1109,7 +1113,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
         {
             foreach (KSessionRequest request in IterateWithRemovalOfAllRequests())
             {
-                CancelRequest(request, KernelResult.PortRemoteClosed);
+                FinishRequest(request, KernelResult.PortRemoteClosed);
             }
         }
 
@@ -1180,7 +1184,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
             return hasRequest;
         }
 
-        private void CancelRequest(KSessionRequest request, KernelResult result)
+        private void FinishRequest(KSessionRequest request, KernelResult result)
         {
             KProcess clientProcess = request.ClientThread.Owner;
             KProcess serverProcess = request.ServerProcess;
@@ -1221,14 +1225,15 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
         {
             KProcess clientProcess = request.ClientThread.Owner;
 
-            ulong address = clientProcess.MemoryManager.GetDramAddressFromVa(request.CustomCmdBuffAddr);
+            if (result != KernelResult.Success)
+            {
+                ulong address = clientProcess.MemoryManager.GetDramAddressFromVa(request.CustomCmdBuffAddr);
 
-            KernelContext.Memory.Write<ulong>(address, 0);
-            KernelContext.Memory.Write(address + 8, (int)result);
+                KernelContext.Memory.Write<ulong>(address, 0);
+                KernelContext.Memory.Write(address + 8, (int)result);
+            }
 
-            clientProcess.MemoryManager.UnborrowIpcBuffer(
-                request.CustomCmdBuffAddr,
-                request.CustomCmdBuffSize);
+            clientProcess.MemoryManager.UnborrowIpcBuffer(request.CustomCmdBuffAddr, request.CustomCmdBuffSize);
 
             request.AsyncEvent.Signal();
         }
diff --git a/Ryujinx.HLE/HOS/Kernel/Ipc/KSession.cs b/Ryujinx.HLE/HOS/Kernel/Ipc/KSession.cs
index 25e6eee5..4b5886a9 100644
--- a/Ryujinx.HLE/HOS/Kernel/Ipc/KSession.cs
+++ b/Ryujinx.HLE/HOS/Kernel/Ipc/KSession.cs
@@ -11,10 +11,10 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
 
         private bool _hasBeenInitialized;
 
-        public KSession(KernelContext context) : base(context)
+        public KSession(KernelContext context, KClientPort parentPort = null) : base(context)
         {
             ServerSession = new KServerSession(context, this);
-            ClientSession = new KClientSession(context, this);
+            ClientSession = new KClientSession(context, this, parentPort);
 
             _hasBeenInitialized = true;
         }
@@ -54,10 +54,11 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
         {
             if (_hasBeenInitialized)
             {
+                ClientSession.DisconnectFromPort();
+
                 KProcess creatorProcess = ClientSession.CreatorProcess;
 
                 creatorProcess.ResourceLimit?.Release(LimitableResource.Session, 1);
-
                 creatorProcess.DecrementReferenceCount();
             }
         }
diff --git a/Ryujinx.HLE/HOS/Kernel/Ipc/KSessionRequest.cs b/Ryujinx.HLE/HOS/Kernel/Ipc/KSessionRequest.cs
index f3467f39..31ddfc9c 100644
--- a/Ryujinx.HLE/HOS/Kernel/Ipc/KSessionRequest.cs
+++ b/Ryujinx.HLE/HOS/Kernel/Ipc/KSessionRequest.cs
@@ -17,13 +17,15 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
         public ulong CustomCmdBuffSize { get; }
 
         public KSessionRequest(
-            KThread clientThread,
-            ulong   customCmdBuffAddr,
-            ulong   customCmdBuffSize)
+            KThread        clientThread,
+            ulong          customCmdBuffAddr,
+            ulong          customCmdBuffSize,
+            KWritableEvent asyncEvent = null)
         {
             ClientThread      = clientThread;
             CustomCmdBuffAddr = customCmdBuffAddr;
             CustomCmdBuffSize = customCmdBuffSize;
+            AsyncEvent        = asyncEvent;
 
             BufferDescriptorTable = new KBufferDescriptorTable();
         }