From e3fb9b5e0049b87a25c551219d4b009550af5f6d Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Fri, 14 Apr 2023 22:53:37 -0400
Subject: vulkan: use plain fences when timeline semaphores are not available

---
 .../renderer_vulkan/vk_master_semaphore.cpp        | 139 ++++++++++++++++++++-
 1 file changed, 138 insertions(+), 1 deletion(-)

(limited to 'src/video_core/renderer_vulkan/vk_master_semaphore.cpp')

diff --git a/src/video_core/renderer_vulkan/vk_master_semaphore.cpp b/src/video_core/renderer_vulkan/vk_master_semaphore.cpp
index 8aa07ef9d..47c74e4d8 100644
--- a/src/video_core/renderer_vulkan/vk_master_semaphore.cpp
+++ b/src/video_core/renderer_vulkan/vk_master_semaphore.cpp
@@ -10,7 +10,14 @@
 
 namespace Vulkan {
 
-MasterSemaphore::MasterSemaphore(const Device& device) {
+MasterSemaphore::MasterSemaphore(const Device& device_) : device(device_) {
+    if (!device.HasTimelineSemaphore()) {
+        static constexpr VkFenceCreateInfo fence_ci{
+            .sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO, .pNext = nullptr, .flags = 0};
+        fence = device.GetLogical().CreateFence(fence_ci);
+        return;
+    }
+
     static constexpr VkSemaphoreTypeCreateInfo semaphore_type_ci{
         .sType = VK_STRUCTURE_TYPE_SEMAPHORE_TYPE_CREATE_INFO,
         .pNext = nullptr,
@@ -42,4 +49,134 @@ MasterSemaphore::MasterSemaphore(const Device& device) {
 
 MasterSemaphore::~MasterSemaphore() = default;
 
+void MasterSemaphore::Refresh() {
+    if (!semaphore) {
+        // If we don't support timeline semaphores, there's nothing to refresh
+        return;
+    }
+
+    u64 this_tick{};
+    u64 counter{};
+    do {
+        this_tick = gpu_tick.load(std::memory_order_acquire);
+        counter = semaphore.GetCounter();
+        if (counter < this_tick) {
+            return;
+        }
+    } while (!gpu_tick.compare_exchange_weak(this_tick, counter, std::memory_order_release,
+                                             std::memory_order_relaxed));
+}
+
+void MasterSemaphore::Wait(u64 tick) {
+    if (!semaphore) {
+        // If we don't support timeline semaphores, use an atomic wait
+        while (true) {
+            u64 current_value = gpu_tick.load(std::memory_order_relaxed);
+            if (current_value >= tick) {
+                return;
+            }
+            gpu_tick.wait(current_value);
+        }
+
+        return;
+    }
+
+    // No need to wait if the GPU is ahead of the tick
+    if (IsFree(tick)) {
+        return;
+    }
+
+    // Update the GPU tick and try again
+    Refresh();
+
+    if (IsFree(tick)) {
+        return;
+    }
+
+    // If none of the above is hit, fallback to a regular wait
+    while (!semaphore.Wait(tick)) {
+    }
+
+    Refresh();
+}
+
+VkResult MasterSemaphore::SubmitQueue(vk::CommandBuffer& cmdbuf, VkSemaphore signal_semaphore,
+                                      VkSemaphore wait_semaphore, u64 host_tick) {
+    if (semaphore) {
+        return SubmitQueueTimeline(cmdbuf, signal_semaphore, wait_semaphore, host_tick);
+    } else {
+        return SubmitQueueFence(cmdbuf, signal_semaphore, wait_semaphore, host_tick);
+    }
+}
+
+static constexpr std::array<VkPipelineStageFlags, 2> wait_stage_masks{
+    VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
+    VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
+};
+
+VkResult MasterSemaphore::SubmitQueueTimeline(vk::CommandBuffer& cmdbuf,
+                                              VkSemaphore signal_semaphore,
+                                              VkSemaphore wait_semaphore, u64 host_tick) {
+    const VkSemaphore timeline_semaphore = *semaphore;
+
+    const u32 num_signal_semaphores = signal_semaphore ? 2 : 1;
+    const std::array signal_values{host_tick, u64(0)};
+    const std::array signal_semaphores{timeline_semaphore, signal_semaphore};
+
+    const u32 num_wait_semaphores = wait_semaphore ? 2 : 1;
+    const std::array wait_values{host_tick - 1, u64(1)};
+    const std::array wait_semaphores{timeline_semaphore, wait_semaphore};
+
+    const VkTimelineSemaphoreSubmitInfo timeline_si{
+        .sType = VK_STRUCTURE_TYPE_TIMELINE_SEMAPHORE_SUBMIT_INFO,
+        .pNext = nullptr,
+        .waitSemaphoreValueCount = num_wait_semaphores,
+        .pWaitSemaphoreValues = wait_values.data(),
+        .signalSemaphoreValueCount = num_signal_semaphores,
+        .pSignalSemaphoreValues = signal_values.data(),
+    };
+    const VkSubmitInfo submit_info{
+        .sType = VK_STRUCTURE_TYPE_SUBMIT_INFO,
+        .pNext = &timeline_si,
+        .waitSemaphoreCount = num_wait_semaphores,
+        .pWaitSemaphores = wait_semaphores.data(),
+        .pWaitDstStageMask = wait_stage_masks.data(),
+        .commandBufferCount = 1,
+        .pCommandBuffers = cmdbuf.address(),
+        .signalSemaphoreCount = num_signal_semaphores,
+        .pSignalSemaphores = signal_semaphores.data(),
+    };
+
+    return device.GetGraphicsQueue().Submit(submit_info);
+}
+
+VkResult MasterSemaphore::SubmitQueueFence(vk::CommandBuffer& cmdbuf, VkSemaphore signal_semaphore,
+                                           VkSemaphore wait_semaphore, u64 host_tick) {
+    const u32 num_signal_semaphores = signal_semaphore ? 1 : 0;
+    const u32 num_wait_semaphores = wait_semaphore ? 1 : 0;
+
+    const VkSubmitInfo submit_info{
+        .sType = VK_STRUCTURE_TYPE_SUBMIT_INFO,
+        .pNext = nullptr,
+        .waitSemaphoreCount = num_wait_semaphores,
+        .pWaitSemaphores = &wait_semaphore,
+        .pWaitDstStageMask = wait_stage_masks.data(),
+        .commandBufferCount = 1,
+        .pCommandBuffers = cmdbuf.address(),
+        .signalSemaphoreCount = num_signal_semaphores,
+        .pSignalSemaphores = &signal_semaphore,
+    };
+
+    auto result = device.GetGraphicsQueue().Submit(submit_info, *fence);
+
+    if (result == VK_SUCCESS) {
+        fence.Wait();
+        fence.Reset();
+        gpu_tick.store(host_tick);
+        gpu_tick.notify_all();
+    }
+
+    return result;
+}
+
 } // namespace Vulkan
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