gl_texture_cache: Enable async downloads

src/video_core/renderer_opengl/gl_buffer_cache.cpp

@@ -151,7 +151,7 @@ StagingBufferMap BufferCacheRuntime::DownloadStagingBuffer(size_t size, bool def
 }
 
 void BufferCacheRuntime::FreeDeferredStagingBuffer(StagingBufferMap& buffer) {
-    staging_buffer_pool.FreeDeferredStagingBuffer(buffer.index);
+    staging_buffer_pool.FreeDeferredStagingBuffer(buffer);
 }
 
 u64 BufferCacheRuntime::GetDeviceMemoryUsage() const {

src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp

@@ -45,6 +45,7 @@ StagingBufferMap StagingBuffers::RequestMap(size_t requested_size, bool insert_f
 }
 
 void StagingBuffers::FreeDeferredStagingBuffer(size_t index) {
+    ASSERT(allocs[index].deferred);
     allocs[index].deferred = false;
 }
 
@@ -152,8 +153,8 @@ StagingBufferMap StagingBufferPool::RequestDownloadBuffer(size_t size, bool defe
     return download_buffers.RequestMap(size, false, deferred);
 }
 
-void StagingBufferPool::FreeDeferredStagingBuffer(size_t index) {
-    download_buffers.FreeDeferredStagingBuffer(index);
+void StagingBufferPool::FreeDeferredStagingBuffer(StagingBufferMap& buffer) {
+    download_buffers.FreeDeferredStagingBuffer(buffer.index);
 }
 
 } // namespace OpenGL

src/video_core/renderer_opengl/gl_staging_buffer_pool.h

@@ -93,7 +93,7 @@ public:
 
     StagingBufferMap RequestUploadBuffer(size_t size);
     StagingBufferMap RequestDownloadBuffer(size_t size, bool deferred = false);
-    void FreeDeferredStagingBuffer(size_t index);
+    void FreeDeferredStagingBuffer(StagingBufferMap& buffer);
 
 private:
     StagingBuffers upload_buffers{GL_MAP_WRITE_BIT, GL_MAP_WRITE_BIT | GL_MAP_FLUSH_EXPLICIT_BIT};

src/video_core/renderer_opengl/gl_texture_cache.cpp

@@ -557,8 +557,12 @@ StagingBufferMap TextureCacheRuntime::UploadStagingBuffer(size_t size) {
     return staging_buffer_pool.RequestUploadBuffer(size);
 }
 
-StagingBufferMap TextureCacheRuntime::DownloadStagingBuffer(size_t size) {
-    return staging_buffer_pool.RequestDownloadBuffer(size);
+StagingBufferMap TextureCacheRuntime::DownloadStagingBuffer(size_t size, bool deferred) {
+    return staging_buffer_pool.RequestDownloadBuffer(size, deferred);
+}
+
+void TextureCacheRuntime::FreeDeferredStagingBuffer(StagingBufferMap& buffer) {
+    staging_buffer_pool.FreeDeferredStagingBuffer(buffer);
 }
 
 u64 TextureCacheRuntime::GetDeviceMemoryUsage() const {

src/video_core/renderer_opengl/gl_texture_cache.h

@@ -74,7 +74,9 @@ public:
 
     StagingBufferMap UploadStagingBuffer(size_t size);
 
-    StagingBufferMap DownloadStagingBuffer(size_t size);
+    StagingBufferMap DownloadStagingBuffer(size_t size, bool deferred = false);
+
+    void FreeDeferredStagingBuffer(StagingBufferMap& buffer);
 
     u64 GetDeviceLocalMemory() const {
         return device_access_memory;
@@ -359,7 +361,7 @@ struct TextureCacheParams {
     static constexpr bool FRAMEBUFFER_BLITS = true;
     static constexpr bool HAS_EMULATED_COPIES = true;
     static constexpr bool HAS_DEVICE_MEMORY_INFO = true;
-    static constexpr bool IMPLEMENTS_ASYNC_DOWNLOADS = false;
+    static constexpr bool IMPLEMENTS_ASYNC_DOWNLOADS = true;
 
     using Runtime = OpenGL::TextureCacheRuntime;
     using Image = OpenGL::Image;
@@ -367,7 +369,7 @@ struct TextureCacheParams {
     using ImageView = OpenGL::ImageView;
     using Sampler = OpenGL::Sampler;
     using Framebuffer = OpenGL::Framebuffer;
-    using AsyncBuffer = u32;
+    using AsyncBuffer = OpenGL::StagingBufferMap;
     using BufferType = GLuint;
 };