buffer_cache: Simplify uniform disabling logic

src/video_core/buffer_cache/buffer_cache.h

@@ -110,6 +110,8 @@ public:
 
     void BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAddr gpu_addr, u32 size);
 
+    void DisableGraphicsUniformBuffer(size_t stage, u32 index);
+
     void UpdateGraphicsBuffers(bool is_indexed);
 
     void UpdateComputeBuffers();
@@ -419,10 +421,6 @@ template <class P>
 void BufferCache<P>::BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAddr gpu_addr,
                                                u32 size) {
     const std::optional<VAddr> cpu_addr = gpu_memory.GpuToCpuAddress(gpu_addr);
-    if (!cpu_addr) {
-        uniform_buffers[stage][index] = NULL_BINDING;
-        return;
-    }
     const Binding binding{
         .cpu_addr = *cpu_addr,
         .size = size,
@@ -431,6 +429,11 @@ void BufferCache<P>::BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAddr
     uniform_buffers[stage][index] = binding;
 }
 
+template <class P>
+void BufferCache<P>::DisableGraphicsUniformBuffer(size_t stage, u32 index) {
+    uniform_buffers[stage][index] = NULL_BINDING;
+}
+
 template <class P>
 void BufferCache<P>::UpdateGraphicsBuffers(bool is_indexed) {
     MICROPROFILE_SCOPE(GPU_PrepareBuffers);

src/video_core/engines/maxwell_3d.cpp

@@ -578,8 +578,12 @@ void Maxwell3D::ProcessCBBind(size_t stage_index) {
     buffer.size = regs.const_buffer.cb_size;
 
     const bool is_enabled = bind_data.valid.Value() != 0;
-    const GPUVAddr gpu_addr = is_enabled ? regs.const_buffer.BufferAddress() : 0;
-    const u32 size = is_enabled ? regs.const_buffer.cb_size : 0;
+    if (!is_enabled) {
+        rasterizer->DisableGraphicsUniformBuffer(stage_index, bind_data.index);
+        return;
+    }
+    const GPUVAddr gpu_addr = regs.const_buffer.BufferAddress();
+    const u32 size = regs.const_buffer.cb_size;
     rasterizer->BindGraphicsUniformBuffer(stage_index, bind_data.index, gpu_addr, size);
 }
 

src/video_core/memory_manager.cpp

@@ -163,6 +163,9 @@ std::optional<GPUVAddr> MemoryManager::FindFreeRange(std::size_t size, std::size
 }
 
 std::optional<VAddr> MemoryManager::GpuToCpuAddress(GPUVAddr gpu_addr) const {
+    if (gpu_addr == 0) {
+        return std::nullopt;
+    }
     const auto page_entry{GetPageEntry(gpu_addr)};
     if (!page_entry.IsValid()) {
         return std::nullopt;

src/video_core/rasterizer_interface.h

@@ -54,6 +54,9 @@ public:
     virtual void BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAddr gpu_addr,
                                            u32 size) = 0;
 
+    /// Signal disabling of a uniform buffer
+    virtual void DisableGraphicsUniformBuffer(size_t stage, u32 index) = 0;
+
     /// Signal a GPU based semaphore as a fence
     virtual void SignalSemaphore(GPUVAddr addr, u32 value) = 0;
 

src/video_core/renderer_opengl/gl_rasterizer.cpp

@@ -526,6 +526,10 @@ void RasterizerOpenGL::BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAd
     buffer_cache.BindGraphicsUniformBuffer(stage, index, gpu_addr, size);
 }
 
+void RasterizerOpenGL::DisableGraphicsUniformBuffer(size_t stage, u32 index) {
+    buffer_cache.DisableGraphicsUniformBuffer(stage, index);
+}
+
 void RasterizerOpenGL::FlushAll() {}
 
 void RasterizerOpenGL::FlushRegion(VAddr addr, u64 size) {

src/video_core/renderer_opengl/gl_rasterizer.h

@@ -72,6 +72,7 @@ public:
     void ResetCounter(VideoCore::QueryType type) override;
     void Query(GPUVAddr gpu_addr, VideoCore::QueryType type, std::optional<u64> timestamp) override;
     void BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAddr gpu_addr, u32 size) override;
+    void DisableGraphicsUniformBuffer(size_t stage, u32 index) override;
     void FlushAll() override;
     void FlushRegion(VAddr addr, u64 size) override;
     bool MustFlushRegion(VAddr addr, u64 size) override;

src/video_core/renderer_vulkan/vk_rasterizer.cpp

@@ -476,6 +476,10 @@ void RasterizerVulkan::BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAd
     buffer_cache.BindGraphicsUniformBuffer(stage, index, gpu_addr, size);
 }
 
+void Vulkan::RasterizerVulkan::DisableGraphicsUniformBuffer(size_t stage, u32 index) {
+    buffer_cache.DisableGraphicsUniformBuffer(stage, index);
+}
+
 void RasterizerVulkan::FlushAll() {}
 
 void RasterizerVulkan::FlushRegion(VAddr addr, u64 size) {

src/video_core/renderer_vulkan/vk_rasterizer.h

@@ -64,6 +64,7 @@ public:
     void ResetCounter(VideoCore::QueryType type) override;
     void Query(GPUVAddr gpu_addr, VideoCore::QueryType type, std::optional<u64> timestamp) override;
     void BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAddr gpu_addr, u32 size) override;
+    void DisableGraphicsUniformBuffer(size_t stage, u32 index) override;
     void FlushAll() override;
     void FlushRegion(VAddr addr, u64 size) override;
     bool MustFlushRegion(VAddr addr, u64 size) override;