From e580073430d1857a70c566dffc1378f6f2bdcce1 Mon Sep 17 00:00:00 2001
From: IndecisiveTurtle <47210458+raphaelthegreat@users.noreply.github.com>
Date: Mon, 23 Jun 2025 01:10:22 +0300
Subject: [PATCH] liverpool: Use pending downloads API for rewind

Prevents creating huge buffers
---
 src/video_core/amdgpu/liverpool.cpp              |  8 ++------
 src/video_core/buffer_cache/buffer_cache.cpp     | 10 +++++++---
 src/video_core/buffer_cache/buffer_cache.h       |  2 +-
 src/video_core/renderer_vulkan/vk_rasterizer.cpp |  4 ++--
 src/video_core/renderer_vulkan/vk_rasterizer.h   |  2 +-
 src/video_core/renderer_vulkan/vk_scheduler.h    |  4 ++--
 6 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/video_core/amdgpu/liverpool.cpp b/src/video_core/amdgpu/liverpool.cpp
index fd38e3fbf..65dad7da8 100644
--- a/src/video_core/amdgpu/liverpool.cpp
+++ b/src/video_core/amdgpu/liverpool.cpp
@@ -708,9 +708,7 @@ Liverpool::Task Liverpool::ProcessGraphics(std::span<const u32> dcb, std::span<c
             }
             case PM4ItOpcode::Rewind: {
                 if (rasterizer) {
-                    const VAddr flush_addr = VAddr(reinterpret_cast<const u32*>(header));
-                    const u32 flush_size = dcb.size_bytes();
-                    rasterizer->ReadMemory(flush_addr, flush_size);
+                    rasterizer->CommitPendingDownloads(true);
                 }
                 const PM4CmdRewind* rewind = reinterpret_cast<const PM4CmdRewind*>(header);
                 while (!rewind->Valid()) {
@@ -915,9 +913,7 @@ Liverpool::Task Liverpool::ProcessCompute(const u32* acb, u32 acb_dwords, u32 vq
         }
         case PM4ItOpcode::Rewind: {
             if (rasterizer) {
-                const VAddr flush_addr = VAddr(reinterpret_cast<const u32*>(header));
-                const u32 flush_size = acb_dwords * sizeof(u32);
-                rasterizer->ReadMemory(flush_addr, flush_size);
+                rasterizer->CommitPendingDownloads(true);
             }
             const PM4CmdRewind* rewind = reinterpret_cast<const PM4CmdRewind*>(header);
             while (!rewind->Valid()) {
diff --git a/src/video_core/buffer_cache/buffer_cache.cpp b/src/video_core/buffer_cache/buffer_cache.cpp
index 70bc9c226..54d516e71 100644
--- a/src/video_core/buffer_cache/buffer_cache.cpp
+++ b/src/video_core/buffer_cache/buffer_cache.cpp
@@ -27,7 +27,7 @@ static constexpr size_t UboStreamBufferSize = 128_MB;
 static constexpr size_t DownloadBufferSize = 128_MB;
 static constexpr size_t DeviceBufferSize = 128_MB;
 static constexpr size_t MaxPageFaults = 1024;
-static constexpr size_t DownloadSizeThreshold = 2_MB;
+static constexpr size_t DownloadSizeThreshold = 1_MB;
 
 BufferCache::BufferCache(const Vulkan::Instance& instance_, Vulkan::Scheduler& scheduler_,
                          AmdGpu::Liverpool* liverpool_, TextureCache& texture_cache_,
@@ -188,7 +188,7 @@ void BufferCache::DownloadBufferMemory(const Buffer& buffer, VAddr device_addr,
     }
 }
 
-bool BufferCache::CommitPendingDownloads() {
+bool BufferCache::CommitPendingDownloads(bool wait_done) {
     if (pending_download_ranges.Empty()) {
         return false;
     }
@@ -254,7 +254,11 @@ bool BufferCache::CommitPendingDownloads() {
             }
         }
     });
-    scheduler.Flush();
+    if (wait_done) {
+        scheduler.Finish();
+    } else {
+        scheduler.Flush();
+    }
     return true;
 }
 
diff --git a/src/video_core/buffer_cache/buffer_cache.h b/src/video_core/buffer_cache/buffer_cache.h
index 8e6253633..48e27ba81 100644
--- a/src/video_core/buffer_cache/buffer_cache.h
+++ b/src/video_core/buffer_cache/buffer_cache.h
@@ -128,7 +128,7 @@ public:
     void CopyBuffer(VAddr dst, VAddr src, u32 num_bytes, bool dst_gds, bool src_gds);
 
     /// Schedules pending GPU modified ranges since last commit to be copied back the host memory.
-    bool CommitPendingDownloads();
+    bool CommitPendingDownloads(bool wait_done);
 
     /// Obtains a buffer for the specified region.
     [[nodiscard]] std::pair<Buffer*, u32> ObtainBuffer(VAddr gpu_addr, u32 size, bool is_written,
diff --git a/src/video_core/renderer_vulkan/vk_rasterizer.cpp b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
index 21b6ee057..b3a2a53ba 100644
--- a/src/video_core/renderer_vulkan/vk_rasterizer.cpp
+++ b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
@@ -60,9 +60,9 @@ void Rasterizer::CpSync() {
                            vk::DependencyFlagBits::eByRegion, ib_barrier, {}, {});
 }
 
-bool Rasterizer::CommitPendingDownloads() {
+bool Rasterizer::CommitPendingDownloads(bool wait_done) {
     scheduler.PopPendingOperations();
-    return buffer_cache.CommitPendingDownloads();
+    return buffer_cache.CommitPendingDownloads(wait_done);
 }
 
 bool Rasterizer::FilterDraw() {
diff --git a/src/video_core/renderer_vulkan/vk_rasterizer.h b/src/video_core/renderer_vulkan/vk_rasterizer.h
index 1ae615b52..dfcb9f775 100644
--- a/src/video_core/renderer_vulkan/vk_rasterizer.h
+++ b/src/video_core/renderer_vulkan/vk_rasterizer.h
@@ -65,7 +65,7 @@ public:
     void UnmapMemory(VAddr addr, u64 size);
 
     void CpSync();
-    bool CommitPendingDownloads();
+    bool CommitPendingDownloads(bool wait_done = false);
     u64 Flush();
     void Finish();
     void ProcessFaults();
diff --git a/src/video_core/renderer_vulkan/vk_scheduler.h b/src/video_core/renderer_vulkan/vk_scheduler.h
index 84c28ac67..c19c326c7 100644
--- a/src/video_core/renderer_vulkan/vk_scheduler.h
+++ b/src/video_core/renderer_vulkan/vk_scheduler.h
@@ -357,8 +357,8 @@ public:
     }
 
     /// Defers an operation until the gpu has reached the current cpu tick.
-    void DeferOperation(Common::UniqueFunction<void>&& func, bool prev_tick = false) {
-        pending_ops.emplace(std::move(func), prev_tick ? CurrentTick() - 1 : CurrentTick());
+    void DeferOperation(Common::UniqueFunction<void>&& func) {
+        pending_ops.emplace(std::move(func), CurrentTick());
     }
 
     static std::mutex submit_mutex;