From f73c3708a5b3113f52636fc1921b3a84acca678c Mon Sep 17 00:00:00 2001
From: zilmar <zilmar@pj64-emu.com>
Date: Thu, 5 Oct 2023 14:45:17 +1030
Subject: [PATCH] Core: Fix up tlb Probe and call EXC_MOD when tlb is not dirty

---
 .../N64System/Mips/Register.cpp               |  7 ++-
 Source/Project64-core/N64System/Mips/TLB.cpp  | 52 ++++++++++---------
 Source/Project64-core/N64System/Mips/TLB.h    |  2 +-
 Source/Project64-core/N64System/N64System.cpp |  4 +-
 4 files changed, 37 insertions(+), 28 deletions(-)

diff --git a/Source/Project64-core/N64System/Mips/Register.cpp b/Source/Project64-core/N64System/Mips/Register.cpp
index eadf949e0..f7bba36dc 100644
--- a/Source/Project64-core/N64System/Mips/Register.cpp
+++ b/Source/Project64-core/N64System/Mips/Register.cpp
@@ -788,7 +788,12 @@ void CRegisters::TriggerAddressException(uint64_t Address, uint32_t ExceptionCod
     bool SpecialOffset = false;
     if (ExceptionCode == EXC_RMISS || ExceptionCode == EXC_WMISS)
     {
-        SpecialOffset = !m_TLB.AddressDefined(Address);
+        bool Dirty;
+        SpecialOffset = !m_TLB.AddressDefined(Address, Dirty);
+        if (!Dirty)
+        {
+            ExceptionCode = EXC_MOD;
+        }
     }
 
     BAD_VADDR_REGISTER = Address;
diff --git a/Source/Project64-core/N64System/Mips/TLB.cpp b/Source/Project64-core/N64System/Mips/TLB.cpp
index e7843eb25..11ccd11e5 100644
--- a/Source/Project64-core/N64System/Mips/TLB.cpp
+++ b/Source/Project64-core/N64System/Mips/TLB.cpp
@@ -53,21 +53,26 @@ void CTLB::Reset(bool InvalidateTLB)
     COP0StatusChanged();
 }
 
-bool CTLB::AddressDefined(uint64_t VAddr)
+bool CTLB::AddressDefined(uint64_t VAddr, bool & Dirty)
 {
-    if (VAddr >= 0x80000000 && VAddr <= 0xBFFFFFFF)
+    Dirty = true;
+    MemorySegment Segment = VAddrMemorySegment(VAddr);
+    if (Segment == MemorySegment_Mapped)
     {
-        return true;
-    }
-
-    for (uint32_t i = 0; i < 64; i++)
-    {
-        if (m_FastTlb[i].ValidEntry &&
-            VAddr >= m_FastTlb[i].VSTART &&
-            VAddr <= m_FastTlb[i].VEND)
+        for (uint32_t i = 0; i < 64; i++)
         {
+            if (!m_FastTlb[i].GLOBAL || !m_FastTlb[i].ValidEntry || VAddr < m_FastTlb[i].VSTART || VAddr > m_FastTlb[i].VEND + 1)
+            {
+                continue;
+            }
+            if (!m_FastTlb[i].VALID)
+            {
+                return true;
+            }
+            Dirty = m_FastTlb[i].DIRTY;
             return true;
         }
+        return false;
     }
     return false;
 }
@@ -88,23 +93,22 @@ void CTLB::Probe()
             continue;
         }
 
-        uint64_t & TlbEntryHiValue = m_tlb[i].EntryHi.Value;
-        uint32_t Mask = (uint32_t)(~m_tlb[i].PageMask.Mask << 13);
-        uint32_t TlbValueMasked = TlbEntryHiValue & Mask;
-        uint32_t EntryHiMasked = m_Reg.ENTRYHI_REGISTER.Value & Mask;
+        const COP0EntryHi & TlbEntryHiValue = m_tlb[i].EntryHi;
+        uint64_t Mask = ~m_tlb[i].PageMask.Mask << 13;
+        uint64_t TlbValueMasked = TlbEntryHiValue.Value & Mask;
+        uint64_t EntryHiMasked = m_Reg.ENTRYHI_REGISTER.Value & Mask;
 
-        if (TlbValueMasked == EntryHiMasked)
+        if (TlbValueMasked != EntryHiMasked || 
+            TlbEntryHiValue.R != m_Reg.ENTRYHI_REGISTER.R ||
+            (m_tlb[i].EntryLo0.GLOBAL == 0 || m_tlb[i].EntryLo1.GLOBAL == 0) && TlbEntryHiValue.ASID != m_Reg.ENTRYHI_REGISTER.ASID)
         {
-            if ((TlbEntryHiValue & 0x100) != 0 ||                                    // Global
-                ((TlbEntryHiValue & 0xFF) == (m_Reg.ENTRYHI_REGISTER.Value & 0xFF))) // SameAsid
-            {
-                m_Reg.INDEX_REGISTER = i;
-                uint32_t FastIndx = i << 1;
-                m_FastTlb[FastIndx].Probed = true;
-                m_FastTlb[FastIndx + 1].Probed = true;
-                return;
-            }
+            continue;
         }
+        m_Reg.INDEX_REGISTER = i;
+        uint32_t FastIndx = i << 1;
+        m_FastTlb[FastIndx].Probed = true;
+        m_FastTlb[FastIndx + 1].Probed = true;
+        break;
     }
     WriteTrace(TraceTLB, TraceDebug, "Done");
 }
diff --git a/Source/Project64-core/N64System/Mips/TLB.h b/Source/Project64-core/N64System/Mips/TLB.h
index 0af20b635..b2c6f1006 100644
--- a/Source/Project64-core/N64System/Mips/TLB.h
+++ b/Source/Project64-core/N64System/Mips/TLB.h
@@ -58,7 +58,7 @@ public:
     void ReadEntry();
     void WriteEntry(uint32_t Index, bool Random);
     void COP0StatusChanged(void);
-    bool AddressDefined(uint64_t VAddr);
+    bool AddressDefined(uint64_t VAddr, bool & Dirty); 
     TLB_ENTRY & TlbEntry(int32_t Entry);
 
     bool VAddrToPAddr(uint64_t VAddr, uint32_t & PAddr, bool & MemoryUnused);
diff --git a/Source/Project64-core/N64System/N64System.cpp b/Source/Project64-core/N64System/N64System.cpp
index 85c927d9d..ccb64cd3c 100644
--- a/Source/Project64-core/N64System/N64System.cpp
+++ b/Source/Project64-core/N64System/N64System.cpp
@@ -2028,13 +2028,13 @@ bool CN64System::LoadState(const char * FileName)
                 LoadedZipFile = true;
                 continue;
             }
-            if (LoadedZipFile && Value == SaveID_1 && port == UNZ_OK)
+            if (LoadedZipFile && SaveID == SaveID_1 && port == UNZ_OK)
             {
                 // Extra info v1
                 // System timers info
                 m_SystemTimer.LoadData(file);
             }
-            if (LoadedZipFile && Value == SaveID_2 && port == UNZ_OK)
+            if (LoadedZipFile && SaveID == SaveID_2 && port == UNZ_OK)
             {
                 // Extra info v2 (Project64 2.4)
                 // Disk interface info