6 files changed, 74 insertions, 44 deletions

diff --git a/src/video_core/renderer_opengl/gl_buffer_cache.cpp b/src/video_core/renderer_opengl/gl_buffer_cache.cpp
index dfd696de6..ed188b435 100644
--- a/src/video_core/renderer_opengl/gl_buffer_cache.cpp
+++ b/src/video_core/renderer_opengl/gl_buffer_cache.cpp
@@ -146,8 +146,12 @@ StagingBufferMap BufferCacheRuntime::UploadStagingBuffer(size_t size) {
     return staging_buffer_pool.RequestUploadBuffer(size);
 }
 
-StagingBufferMap BufferCacheRuntime::DownloadStagingBuffer(size_t size) {
-    return staging_buffer_pool.RequestDownloadBuffer(size);
+StagingBufferMap BufferCacheRuntime::DownloadStagingBuffer(size_t size, bool deferred) {
+    return staging_buffer_pool.RequestDownloadBuffer(size, deferred);
+}
+
+void BufferCacheRuntime::FreeDeferredStagingBuffer(StagingBufferMap& buffer) {
+    staging_buffer_pool.FreeDeferredStagingBuffer(buffer);
 }
 
 u64 BufferCacheRuntime::GetDeviceMemoryUsage() const {
diff --git a/src/video_core/renderer_opengl/gl_buffer_cache.h b/src/video_core/renderer_opengl/gl_buffer_cache.h
index 000f29a82..1e8708f59 100644
--- a/src/video_core/renderer_opengl/gl_buffer_cache.h
+++ b/src/video_core/renderer_opengl/gl_buffer_cache.h
@@ -66,7 +66,9 @@ public:
 
     [[nodiscard]] StagingBufferMap UploadStagingBuffer(size_t size);
 
-    [[nodiscard]] StagingBufferMap DownloadStagingBuffer(size_t size);
+    [[nodiscard]] StagingBufferMap DownloadStagingBuffer(size_t size, bool deferred = false);
+
+    void FreeDeferredStagingBuffer(StagingBufferMap& buffer);
 
     bool CanReorderUpload(const Buffer&, std::span<const VideoCommon::BufferCopy>) {
         return false;
@@ -246,7 +248,7 @@ struct BufferCacheParams {
     static constexpr bool NEEDS_BIND_STORAGE_INDEX = true;
     static constexpr bool USE_MEMORY_MAPS = true;
     static constexpr bool SEPARATE_IMAGE_BUFFER_BINDINGS = true;
-    static constexpr bool IMPLEMENTS_ASYNC_DOWNLOADS = false;
+    static constexpr bool IMPLEMENTS_ASYNC_DOWNLOADS = true;
 
     // TODO: Investigate why OpenGL seems to perform worse with persistently mapped buffer uploads
     static constexpr bool USE_MEMORY_MAPS_FOR_UPLOADS = false;
diff --git a/src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp b/src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp
index bbb06e51f..cadad6507 100644
--- a/src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp
+++ b/src/video_core/renderer_opengl/gl_staging_buffer_pool.cpp
@@ -28,63 +28,69 @@ StagingBuffers::StagingBuffers(GLenum storage_flags_, GLenum map_flags_)
 
 StagingBuffers::~StagingBuffers() = default;
 
-StagingBufferMap StagingBuffers::RequestMap(size_t requested_size, bool insert_fence) {
+StagingBufferMap StagingBuffers::RequestMap(size_t requested_size, bool insert_fence,
+                                            bool deferred) {
     MICROPROFILE_SCOPE(OpenGL_BufferRequest);
 
     const size_t index = RequestBuffer(requested_size);
-    OGLSync* const sync = insert_fence ? &syncs[index] : nullptr;
-    sync_indices[index] = insert_fence ? ++current_sync_index : 0;
+    OGLSync* const sync = insert_fence ? &allocs[index].sync : nullptr;
+    allocs[index].sync_index = insert_fence ? ++current_sync_index : 0;
+    allocs[index].deferred = deferred;
     return StagingBufferMap{
-        .mapped_span = std::span(maps[index], requested_size),
+        .mapped_span = std::span(allocs[index].map, requested_size),
         .sync = sync,
-        .buffer = buffers[index].handle,
+        .buffer = allocs[index].buffer.handle,
+        .index = index,
     };
 }
 
+void StagingBuffers::FreeDeferredStagingBuffer(size_t index) {
+    ASSERT(allocs[index].deferred);
+    allocs[index].deferred = false;
+}
+
 size_t StagingBuffers::RequestBuffer(size_t requested_size) {
     if (const std::optional<size_t> index = FindBuffer(requested_size); index) {
         return *index;
     }
-
-    OGLBuffer& buffer = buffers.emplace_back();
-    buffer.Create();
+    StagingBufferAlloc alloc;
+    alloc.buffer.Create();
     const auto next_pow2_size = Common::NextPow2(requested_size);
-    glNamedBufferStorage(buffer.handle, next_pow2_size, nullptr,
+    glNamedBufferStorage(alloc.buffer.handle, next_pow2_size, nullptr,
                          storage_flags | GL_MAP_PERSISTENT_BIT);
-    maps.push_back(static_cast<u8*>(glMapNamedBufferRange(buffer.handle, 0, next_pow2_size,
-                                                          map_flags | GL_MAP_PERSISTENT_BIT)));
-    syncs.emplace_back();
-    sync_indices.emplace_back();
-    sizes.push_back(next_pow2_size);
-
-    ASSERT(syncs.size() == buffers.size() && buffers.size() == maps.size() &&
-           maps.size() == sizes.size());
-
-    return buffers.size() - 1;
+    alloc.map = static_cast<u8*>(glMapNamedBufferRange(alloc.buffer.handle, 0, next_pow2_size,
+                                                       map_flags | GL_MAP_PERSISTENT_BIT));
+    alloc.size = next_pow2_size;
+    allocs.emplace_back(std::move(alloc));
+    return allocs.size() - 1;
 }
 
 std::optional<size_t> StagingBuffers::FindBuffer(size_t requested_size) {
     size_t known_unsignaled_index = current_sync_index + 1;
     size_t smallest_buffer = std::numeric_limits<size_t>::max();
     std::optional<size_t> found;
-    const size_t num_buffers = sizes.size();
+    const size_t num_buffers = allocs.size();
     for (size_t index = 0; index < num_buffers; ++index) {
-        const size_t buffer_size = sizes[index];
+        StagingBufferAlloc& alloc = allocs[index];
+        const size_t buffer_size = alloc.size;
         if (buffer_size < requested_size || buffer_size >= smallest_buffer) {
             continue;
         }
-        if (syncs[index].handle != 0) {
-            if (sync_indices[index] >= known_unsignaled_index) {
+        if (alloc.deferred) {
+            continue;
+        }
+        if (alloc.sync.handle != 0) {
+            if (alloc.sync_index >= known_unsignaled_index) {
                 // This fence is later than a fence that is known to not be signaled
                 continue;
             }
-            if (!syncs[index].IsSignaled()) {
+            if (!alloc.sync.IsSignaled()) {
                 // Since this fence hasn't been signaled, it's safe to assume all later
                 // fences haven't been signaled either
-                known_unsignaled_index = std::min(known_unsignaled_index, sync_indices[index]);
+                known_unsignaled_index = std::min(known_unsignaled_index, alloc.sync_index);
                 continue;
             }
-            syncs[index].Release();
+            alloc.sync.Release();
         }
         smallest_buffer = buffer_size;
         found = index;
@@ -143,8 +149,12 @@ StagingBufferMap StagingBufferPool::RequestUploadBuffer(size_t size) {
     return upload_buffers.RequestMap(size, true);
 }
 
-StagingBufferMap StagingBufferPool::RequestDownloadBuffer(size_t size) {
-    return download_buffers.RequestMap(size, false);
+StagingBufferMap StagingBufferPool::RequestDownloadBuffer(size_t size, bool deferred) {
+    return download_buffers.RequestMap(size, false, deferred);
+}
+
+void StagingBufferPool::FreeDeferredStagingBuffer(StagingBufferMap& buffer) {
+    download_buffers.FreeDeferredStagingBuffer(buffer.index);
 }
 
 } // namespace OpenGL
diff --git a/src/video_core/renderer_opengl/gl_staging_buffer_pool.h b/src/video_core/renderer_opengl/gl_staging_buffer_pool.h
index 60f72d3a0..07a56b4d2 100644
--- a/src/video_core/renderer_opengl/gl_staging_buffer_pool.h
+++ b/src/video_core/renderer_opengl/gl_staging_buffer_pool.h
@@ -26,23 +26,30 @@ struct StagingBufferMap {
     size_t offset = 0;
     OGLSync* sync;
     GLuint buffer;
+    size_t index;
 };
 
 struct StagingBuffers {
     explicit StagingBuffers(GLenum storage_flags_, GLenum map_flags_);
     ~StagingBuffers();
 
-    StagingBufferMap RequestMap(size_t requested_size, bool insert_fence);
+    StagingBufferMap RequestMap(size_t requested_size, bool insert_fence, bool deferred = false);
+
+    void FreeDeferredStagingBuffer(size_t index);
 
     size_t RequestBuffer(size_t requested_size);
 
     std::optional<size_t> FindBuffer(size_t requested_size);
 
-    std::vector<OGLSync> syncs;
-    std::vector<OGLBuffer> buffers;
-    std::vector<u8*> maps;
-    std::vector<size_t> sizes;
-    std::vector<size_t> sync_indices;
+    struct StagingBufferAlloc {
+        OGLSync sync;
+        OGLBuffer buffer;
+        u8* map;
+        size_t size;
+        size_t sync_index;
+        bool deferred;
+    };
+    std::vector<StagingBufferAlloc> allocs;
     GLenum storage_flags;
     GLenum map_flags;
     size_t current_sync_index = 0;
@@ -85,7 +92,8 @@ public:
     ~StagingBufferPool() = default;
 
     StagingBufferMap RequestUploadBuffer(size_t size);
-    StagingBufferMap RequestDownloadBuffer(size_t size);
+    StagingBufferMap RequestDownloadBuffer(size_t size, bool deferred = false);
+    void FreeDeferredStagingBuffer(StagingBufferMap& buffer);
 
 private:
     StagingBuffers upload_buffers{GL_MAP_WRITE_BIT, GL_MAP_WRITE_BIT | GL_MAP_FLUSH_EXPLICIT_BIT};
diff --git a/src/video_core/renderer_opengl/gl_texture_cache.cpp b/src/video_core/renderer_opengl/gl_texture_cache.cpp
index 512eef575..66a5ca03e 100644
--- a/src/video_core/renderer_opengl/gl_texture_cache.cpp
+++ b/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 {
diff --git a/src/video_core/renderer_opengl/gl_texture_cache.h b/src/video_core/renderer_opengl/gl_texture_cache.h
index e71b87e99..34870c81f 100644
--- a/src/video_core/renderer_opengl/gl_texture_cache.h
+++ b/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;
 };