From b0a607539aa58d2b46d8ce46a1ee8d78e1132f9c Mon Sep 17 00:00:00 2001
From: CamilleLaVey <camillelavey99@gmail.com>
Date: Mon, 9 Mar 2026 00:34:12 -0400
Subject: [PATCH] [nce] Added rasterizer caching checks to memory management

---
 src/core/arm/nce/arm_nce.cpp |  4 +++-
 src/core/memory.cpp          | 13 +++++++++++++
 src/core/memory.h            |  4 +++-
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/core/arm/nce/arm_nce.cpp b/src/core/arm/nce/arm_nce.cpp
index 7f8326bf56..3140a78be3 100644
--- a/src/core/arm/nce/arm_nce.cpp
+++ b/src/core/arm/nce/arm_nce.cpp
@@ -199,8 +199,10 @@ bool ArmNce::HandleGuestAccessFault(GuestContext* guest_ctx, void* raw_info, voi
     const Common::ProcessAddress addr = fault_addr & ~Memory::YUZU_PAGEMASK;
     const u64 page_offset = fault_addr & Memory::YUZU_PAGEMASK;
     auto& memory = parent->m_running_thread->GetOwnerProcess()->GetMemory();
+    const bool rasterizer_cached = memory.IsRasterizerCached(addr);
     const bool prefer_precise_channel = ShouldUsePreciseAccessChannel(guest_ctx, fault_addr) ||
-                                        parent->IsPreciseAccessPage(fault_addr);
+                                        parent->IsPreciseAccessPage(fault_addr) ||
+                                        rasterizer_cached;
 
     if (prefer_precise_channel) {
         if (auto next_pc = MatchAndExecuteOneInstruction(memory, &host_ctx, fpctx); next_pc) {
diff --git a/src/core/memory.cpp b/src/core/memory.cpp
index 0ad360c3df..f7031d88b5 100644
--- a/src/core/memory.cpp
+++ b/src/core/memory.cpp
@@ -639,6 +639,15 @@ struct Memory::Impl {
             GetInteger(vaddr), []() {}, []() {});
     }
 
+    [[nodiscard]] bool IsRasterizerCached(const Common::ProcessAddress vaddr) const {
+        const u64 addr = GetInteger(vaddr) & 0xffffffffffffULL;
+        if (!AddressSpaceContains(*current_page_table, addr, 1)) {
+            return false;
+        }
+        return current_page_table->entries[addr >> YUZU_PAGEBITS].ptr.Type() ==
+               Common::PageType::RasterizerCachedMemory;
+    }
+
     /// @brief Reads a particular data type out of memory at the given virtual address.
     /// @param vaddr The virtual address to read the data type from.
     /// @tparam T The data type to read out of memory.
@@ -1036,6 +1045,10 @@ void Memory::RasterizerMarkRegionCached(Common::ProcessAddress vaddr, u64 size,
     impl->RasterizerMarkRegionCached(GetInteger(vaddr), size, cached);
 }
 
+bool Memory::IsRasterizerCached(Common::ProcessAddress vaddr) const {
+    return impl->IsRasterizerCached(vaddr);
+}
+
 void Memory::MarkRegionDebug(Common::ProcessAddress vaddr, u64 size, bool debug) {
     impl->MarkRegionDebug(GetInteger(vaddr), size, debug);
 }
diff --git a/src/core/memory.h b/src/core/memory.h
index 7167efbb84..dcf8ea9656 100644
--- a/src/core/memory.h
+++ b/src/core/memory.h
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: 2014 Citra Emulator Project
@@ -493,6 +493,8 @@ public:
 
     void SetGPUDirtyManagers(std::span<Core::GPUDirtyMemoryManager> managers);
 
+    [[nodiscard]] bool IsRasterizerCached(Common::ProcessAddress vaddr) const;
+
     bool InvalidateNCE(Common::ProcessAddress vaddr, size_t size);
 
     bool InvalidateSeparateHeap(void* fault_address);