From 427b7d06b5ab6d2b06784a9d283eaf836a04c27e Mon Sep 17 00:00:00 2001
From: gdkchan <gab.dark.100@gmail.com>
Date: Sat, 20 Jan 2024 11:11:28 -0300
Subject: Implement a new JIT for Arm devices (#6057)

* Implement a new JIT for Arm devices

* Auto-format

* Make a lot of Assembler members read-only

* More read-only

* Fix more warnings

* ObjectDisposedException.ThrowIf

* New JIT cache for platforms that enforce W^X, currently unused

* Remove unused using

* Fix assert

* Pass memory manager type around

* Safe memory manager mode support + other improvements

* Actual safe memory manager mode masking support

* PR feedback
---
 .../LightningJit/Cache/JitCacheInvalidation.cs     | 79 ++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 src/Ryujinx.Cpu/LightningJit/Cache/JitCacheInvalidation.cs

(limited to 'src/Ryujinx.Cpu/LightningJit/Cache/JitCacheInvalidation.cs')

diff --git a/src/Ryujinx.Cpu/LightningJit/Cache/JitCacheInvalidation.cs b/src/Ryujinx.Cpu/LightningJit/Cache/JitCacheInvalidation.cs
new file mode 100644
index 00000000..cd5f3ede
--- /dev/null
+++ b/src/Ryujinx.Cpu/LightningJit/Cache/JitCacheInvalidation.cs
@@ -0,0 +1,79 @@
+using ARMeilleure.Memory;
+using System;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Cpu.LightningJit.Cache
+{
+    class JitCacheInvalidation
+    {
+        private static readonly int[] _invalidationCode = new int[]
+        {
+            unchecked((int)0xd53b0022), // mrs  x2, ctr_el0
+            unchecked((int)0xd3504c44), // ubfx x4, x2, #16, #4
+            unchecked((int)0x52800083), // mov  w3, #0x4
+            unchecked((int)0x12000c45), // and  w5, w2, #0xf
+            unchecked((int)0x1ac42064), // lsl  w4, w3, w4
+            unchecked((int)0x51000482), // sub  w2, w4, #0x1
+            unchecked((int)0x8a220002), // bic  x2, x0, x2
+            unchecked((int)0x1ac52063), // lsl  w3, w3, w5
+            unchecked((int)0xeb01005f), // cmp  x2, x1
+            unchecked((int)0x93407c84), // sxtw x4, w4
+            unchecked((int)0x540000a2), // b.cs 3c <do_ic_clear>
+            unchecked((int)0xd50b7b22), // dc   cvau, x2
+            unchecked((int)0x8b040042), // add  x2, x2, x4
+            unchecked((int)0xeb02003f), // cmp  x1, x2
+            unchecked((int)0x54ffffa8), // b.hi 2c <dc_clear_loop>
+            unchecked((int)0xd5033b9f), // dsb  ish
+            unchecked((int)0x51000462), // sub  w2, w3, #0x1
+            unchecked((int)0x93407c63), // sxtw x3, w3
+            unchecked((int)0x8a220000), // bic  x0, x0, x2
+            unchecked((int)0xeb00003f), // cmp  x1, x0
+            unchecked((int)0x540000a9), // b.ls 64 <exit>
+            unchecked((int)0xd50b7520), // ic   ivau, x0
+            unchecked((int)0x8b030000), // add  x0, x0, x3
+            unchecked((int)0xeb00003f), // cmp  x1, x0
+            unchecked((int)0x54ffffa8), // b.hi 54 <ic_clear_loop>
+            unchecked((int)0xd5033b9f), // dsb  ish
+            unchecked((int)0xd5033fdf), // isb
+            unchecked((int)0xd65f03c0), // ret
+        };
+
+        private delegate void InvalidateCache(ulong start, ulong end);
+
+        private readonly InvalidateCache _invalidateCache;
+        private readonly ReservedRegion _invalidateCacheCodeRegion;
+
+        private readonly bool _needsInvalidation;
+
+        public JitCacheInvalidation(IJitMemoryAllocator allocator)
+        {
+            // On macOS and Windows, a different path is used to write to the JIT cache, which does the invalidation.
+            if (RuntimeInformation.ProcessArchitecture == Architecture.Arm64)
+            {
+                ulong size = (ulong)_invalidationCode.Length * sizeof(int);
+                ulong mask = (ulong)ReservedRegion.DefaultGranularity - 1;
+
+                size = (size + mask) & ~mask;
+
+                _invalidateCacheCodeRegion = new ReservedRegion(allocator, size);
+                _invalidateCacheCodeRegion.ExpandIfNeeded(size);
+
+                Marshal.Copy(_invalidationCode, 0, _invalidateCacheCodeRegion.Pointer, _invalidationCode.Length);
+
+                _invalidateCacheCodeRegion.Block.MapAsRx(0, size);
+
+                _invalidateCache = Marshal.GetDelegateForFunctionPointer<InvalidateCache>(_invalidateCacheCodeRegion.Pointer);
+
+                _needsInvalidation = true;
+            }
+        }
+
+        public void Invalidate(IntPtr basePointer, ulong size)
+        {
+            if (_needsInvalidation)
+            {
+                _invalidateCache((ulong)basePointer, (ulong)basePointer + size);
+            }
+        }
+    }
+}
-- 
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