From 770e19f51a0767c8fc2b204d9d50fa504a3c4e44 Mon Sep 17 00:00:00 2001
From: Fernando Sahmkow <fsahmkow27@gmail.com>
Date: Wed, 13 Apr 2022 16:20:34 +0200
Subject: [PATCH] Buffer Cache: Deduce vertex array limit from memory layout
 when limit is the highest possible.

---
 src/video_core/buffer_cache/buffer_cache.h | 10 +++++++---
 src/video_core/memory_manager.cpp          |  2 +-
 src/video_core/memory_manager.h            |  4 ++++
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/video_core/buffer_cache/buffer_cache.h b/src/video_core/buffer_cache/buffer_cache.h
index 6eb672475..2e616cee4 100644
--- a/src/video_core/buffer_cache/buffer_cache.h
+++ b/src/video_core/buffer_cache/buffer_cache.h
@@ -1316,12 +1316,16 @@ void BufferCache<P>::UpdateVertexBuffer(u32 index) {
     const GPUVAddr gpu_addr_begin = array.StartAddress();
     const GPUVAddr gpu_addr_end = limit.LimitAddress() + 1;
     const std::optional<VAddr> cpu_addr = gpu_memory->GpuToCpuAddress(gpu_addr_begin);
-    const u32 address_size = static_cast<u32>(gpu_addr_end - gpu_addr_begin);
-    const u32 size = address_size; // TODO: Analyze stride and number of vertices
-    if (array.enable == 0 || size == 0 || !cpu_addr) {
+    u32 address_size = static_cast<u32>(
+        std::min(gpu_addr_end - gpu_addr_begin, static_cast<u64>(std::numeric_limits<u32>::max())));
+    if (array.enable == 0 || address_size == 0 || !cpu_addr) {
         vertex_buffers[index] = NULL_BINDING;
         return;
     }
+    if (!gpu_memory->IsWithinGPUAddressRange(gpu_addr_end)) {
+        address_size = gpu_memory->MaxContinousRange(gpu_addr_begin, address_size);
+    }
+    const u32 size = address_size; // TODO: Analyze stride and number of vertices
     vertex_buffers[index] = Binding{
         .cpu_addr = *cpu_addr,
         .size = size,
diff --git a/src/video_core/memory_manager.cpp b/src/video_core/memory_manager.cpp
index 4a692448e..3cb2d9224 100644
--- a/src/video_core/memory_manager.cpp
+++ b/src/video_core/memory_manager.cpp
@@ -193,7 +193,7 @@ void MemoryManager::Unmap(GPUVAddr gpu_addr, std::size_t size) {
 }
 
 std::optional<VAddr> MemoryManager::GpuToCpuAddress(GPUVAddr gpu_addr) const {
-    if (gpu_addr >= address_space_size) [[unlikely]] {
+    if (!IsWithinGPUAddressRange(gpu_addr)) [[unlikely]] {
         return std::nullopt;
     }
     if (GetEntry<true>(gpu_addr) != EntryType::Mapped) [[unlikely]] {
diff --git a/src/video_core/memory_manager.h b/src/video_core/memory_manager.h
index 9c08edc20..ae4fd98df 100644
--- a/src/video_core/memory_manager.h
+++ b/src/video_core/memory_manager.h
@@ -110,6 +110,10 @@ public:
 
     size_t MaxContinousRange(GPUVAddr gpu_addr, size_t size) const;
 
+    bool IsWithinGPUAddressRange(GPUVAddr gpu_addr) const {
+        return gpu_addr < address_space_size;
+    }
+
 private:
     template <bool is_big_pages, typename FuncMapped, typename FuncReserved, typename FuncUnmapped>
     inline void MemoryOperation(GPUVAddr gpu_src_addr, std::size_t size, FuncMapped&& func_mapped,