1 files changed, 75 insertions, 0 deletions
diff --git a/src/Ryujinx.HLE/HOS/Kernel/Memory/KSharedMemory.cs b/src/Ryujinx.HLE/HOS/Kernel/Memory/KSharedMemory.cs
new file mode 100644
index 00000000..5ec3cd72
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Kernel/Memory/KSharedMemory.cs
@@ -0,0 +1,75 @@
+using Ryujinx.Common;
+using Ryujinx.HLE.HOS.Kernel.Common;
+using Ryujinx.HLE.HOS.Kernel.Process;
+using Ryujinx.Horizon.Common;
+using Ryujinx.Memory;
+
+namespace Ryujinx.HLE.HOS.Kernel.Memory
+{
+    class KSharedMemory : KAutoObject
+    {
+        private readonly KPageList _pageList;
+
+        private readonly ulong _ownerPid;
+
+        private readonly KMemoryPermission _ownerPermission;
+        private readonly KMemoryPermission _userPermission;
+
+        public KSharedMemory(
+            KernelContext context,
+            SharedMemoryStorage storage,
+            ulong ownerPid,
+            KMemoryPermission ownerPermission,
+            KMemoryPermission userPermission) : base(context)
+        {
+            _pageList = storage.GetPageList();
+            _ownerPid = ownerPid;
+            _ownerPermission = ownerPermission;
+            _userPermission = userPermission;
+        }
+
+        public Result MapIntoProcess(
+            KPageTableBase memoryManager,
+            ulong address,
+            ulong size,
+            KProcess process,
+            KMemoryPermission permission)
+        {
+            if (_pageList.GetPagesCount() != BitUtils.DivRoundUp<ulong>(size, KPageTableBase.PageSize))
+            {
+                return KernelResult.InvalidSize;
+            }
+
+            KMemoryPermission expectedPermission = process.Pid == _ownerPid
+                ? _ownerPermission
+                : _userPermission;
+
+            if (permission != expectedPermission)
+            {
+                return KernelResult.InvalidPermission;
+            }
+
+            // On platforms with page size > 4 KB, this can fail due to the address not being page aligned,
+            // we can return an error to force the application to retry with a different address.
+
+            try
+            {
+                return memoryManager.MapPages(address, _pageList, MemoryState.SharedMemory, permission);
+            }
+            catch (InvalidMemoryRegionException)
+            {
+                return KernelResult.InvalidMemState;
+            }
+        }
+
+        public Result UnmapFromProcess(KPageTableBase memoryManager, ulong address, ulong size, KProcess process)
+        {
+            if (_pageList.GetPagesCount() != BitUtils.DivRoundUp<ulong>(size, KPageTableBase.PageSize))
+            {
+                return KernelResult.InvalidSize;
+            }
+
+            return memoryManager.UnmapPages(address, _pageList, MemoryState.SharedMemory);
+        }
+    }
+}
+\ No newline at end of file