From 1c833ddc3c6c58c18187ae87fb43c62e1c517dc8 Mon Sep 17 00:00:00 2001
From: Pokechu22 <Pokechu022@gmail.com>
Date: Wed, 20 Jul 2022 17:44:49 -0700
Subject: [PATCH] Create constant for GPFifo physical address

---
 Source/Core/Core/HW/GPFifo.h                                 | 4 ++++
 Source/Core/Core/HW/MMIO.h                                   | 3 ++-
 .../Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp | 3 ++-
 Source/Core/Core/PowerPC/MMU.cpp                             | 5 +++--
 Source/UnitTests/Core/MMIOTest.cpp                           | 5 +++--
 5 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/Source/Core/Core/HW/GPFifo.h b/Source/Core/Core/HW/GPFifo.h
index 2925e82c05..b29b1b9fde 100644
--- a/Source/Core/Core/HW/GPFifo.h
+++ b/Source/Core/Core/HW/GPFifo.h
@@ -9,6 +9,10 @@ class PointerWrap;
 
 namespace GPFifo
 {
+// This address is configurable in the WPAR SPR, but all games put it at this address
+// (and presumably the hardware backing this system uses this address).
+constexpr u32 GATHER_PIPE_PHYSICAL_ADDRESS = 0x0C008000;
+
 constexpr u32 GATHER_PIPE_SIZE = 32;
 constexpr u32 GATHER_PIPE_EXTRA_SIZE = GATHER_PIPE_SIZE * 16;
 
diff --git a/Source/Core/Core/HW/MMIO.h b/Source/Core/Core/HW/MMIO.h
index d1be58bcfe..92c35bc5f3 100644
--- a/Source/Core/Core/HW/MMIO.h
+++ b/Source/Core/Core/HW/MMIO.h
@@ -13,6 +13,7 @@
 #include "Common/BitUtils.h"
 #include "Common/CommonTypes.h"
 #include "Core/ConfigManager.h"
+#include "Core/HW/GPFifo.h"
 #include "Core/HW/MMIOHandlers.h"
 
 namespace MMIO
@@ -43,7 +44,7 @@ const u32 NUM_MMIOS = NUM_BLOCKS * BLOCK_SIZE;
 // interface.
 inline bool IsMMIOAddress(u32 address)
 {
-  if (address == 0x0C008000)
+  if (address == GPFifo::GATHER_PIPE_PHYSICAL_ADDRESS)
     return false;  // WG Pipe
   if ((address & 0xFFFF0000) == 0x0C000000)
     return true;  // GameCube MMIOs
diff --git a/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp b/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
index 04b305ce37..b7da980db3 100644
--- a/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
+++ b/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
@@ -341,7 +341,8 @@ void Interpreter::mtspr(UGeckoInstruction inst)
     break;
 
   case SPR_WPAR:
-    ASSERT_MSG(POWERPC, rGPR[inst.RD] == 0x0C008000, "Gather pipe @ {:08x}", PC);
+    ASSERT_MSG(POWERPC, rSPR(SPR_WPAR) == GPFifo::GATHER_PIPE_PHYSICAL_ADDRESS,
+               "Gather pipe changed to unexpected address {:08x} @ PC {:08x}", rSPR(SPR_WPAR), PC);
     GPFifo::ResetGatherPipe();
     break;
 
diff --git a/Source/Core/Core/PowerPC/MMU.cpp b/Source/Core/Core/PowerPC/MMU.cpp
index 6c0867deb6..0ff7ccd88e 100644
--- a/Source/Core/Core/PowerPC/MMU.cpp
+++ b/Source/Core/Core/PowerPC/MMU.cpp
@@ -285,7 +285,8 @@ static void WriteToHardware(u32 em_address, const u32 data, const u32 size)
   // Check for a gather pipe write.
   // Note that we must mask the address to correctly emulate certain games;
   // Pac-Man World 3 in particular is affected by this.
-  if (flag == XCheckTLBFlag::Write && (em_address & 0xFFFFF000) == 0x0C008000)
+  if (flag == XCheckTLBFlag::Write &&
+      (em_address & 0xFFFFF000) == GPFifo::GATHER_PIPE_PHYSICAL_ADDRESS)
   {
     switch (size)
     {
@@ -1086,7 +1087,7 @@ bool IsOptimizableGatherPipeWrite(u32 address)
     return false;
 
   // Check whether the translated address equals the address in WPAR.
-  return address == 0x0C008000;
+  return address == GPFifo::GATHER_PIPE_PHYSICAL_ADDRESS;
 }
 
 TranslateResult JitCache_TranslateAddress(u32 address)
diff --git a/Source/UnitTests/Core/MMIOTest.cpp b/Source/UnitTests/Core/MMIOTest.cpp
index 480ba7f7b4..e10ee4e0ce 100644
--- a/Source/UnitTests/Core/MMIOTest.cpp
+++ b/Source/UnitTests/Core/MMIOTest.cpp
@@ -8,6 +8,7 @@
 #include "Common/CommonTypes.h"
 #include "Common/Config/Config.h"
 #include "Common/FileUtil.h"
+#include "Core/HW/GPFifo.h"
 #include "Core/HW/MMIO.h"
 #include "UICommon/UICommon.h"
 
@@ -40,7 +41,7 @@ TEST(IsMMIOAddress, SpecialAddresses)
   SConfig::GetInstance().bWii = true;
 
   // WG Pipe address, should not be handled by MMIO.
-  EXPECT_FALSE(MMIO::IsMMIOAddress(0x0C008000));
+  EXPECT_FALSE(MMIO::IsMMIOAddress(GPFifo::GATHER_PIPE_PHYSICAL_ADDRESS));
 
   // Locked L1 cache allocation.
   EXPECT_FALSE(MMIO::IsMMIOAddress(0xE0000000));
@@ -52,7 +53,7 @@ TEST(IsMMIOAddress, SpecialAddresses)
   // addresses.
   EXPECT_FALSE(MMIO::IsMMIOAddress(0xCC0000E0));
 
-  // And lets check some valid addresses too
+  // And let's check some valid addresses too
   EXPECT_TRUE(MMIO::IsMMIOAddress(0x0C0000E0));  // GameCube MMIOs
   EXPECT_TRUE(MMIO::IsMMIOAddress(0x0D00008C));  // Wii MMIOs
   EXPECT_TRUE(MMIO::IsMMIOAddress(0x0D800F10));  // Mirror of Wii MMIOs