From 2e8e57c20e067ed0d83b2a0bf76c3f5dfac424f3 Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Fri, 11 Mar 2022 00:18:35 -0800
Subject: [PATCH] core: hle: kernel: k_page_buffer: Add KPageBuffer primitive.

---
 src/core/CMakeLists.txt             |  1 +
 src/core/hle/kernel/k_page_buffer.h | 40 +++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 src/core/hle/kernel/k_page_buffer.h

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 5db6a1b3a7..43be5e6529 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -207,6 +207,7 @@ add_library(core STATIC
     hle/kernel/k_memory_region.h
     hle/kernel/k_memory_region_type.h
     hle/kernel/k_page_bitmap.h
+    hle/kernel/k_page_buffer.h
     hle/kernel/k_page_heap.cpp
     hle/kernel/k_page_heap.h
     hle/kernel/k_page_linked_list.h
diff --git a/src/core/hle/kernel/k_page_buffer.h b/src/core/hle/kernel/k_page_buffer.h
new file mode 100644
index 0000000000..c8e04a8896
--- /dev/null
+++ b/src/core/hle/kernel/k_page_buffer.h
@@ -0,0 +1,40 @@
+// Copyright 2022 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+
+#include "common/alignment.h"
+#include "common/assert.h"
+#include "common/common_types.h"
+#include "core/core.h"
+#include "core/device_memory.h"
+#include "core/hle/kernel/memory_types.h"
+
+namespace Kernel {
+
+class KPageBuffer final : public KSlabAllocated<KPageBuffer> {
+private:
+    alignas(PageSize) std::array<u8, PageSize> m_buffer;
+
+public:
+    KPageBuffer() {
+        std::memset(&m_buffer, 0, m_buffer.size());
+    }
+
+    PAddr GetPhysicalAddress(Core::System& system) const {
+        return system.DeviceMemory().GetPhysicalAddr(this);
+    }
+
+    static KPageBuffer* FromPhysicalAddress(Core::System& system, PAddr phys_addr) {
+        ASSERT(Common::IsAligned(phys_addr, PageSize));
+        return reinterpret_cast<KPageBuffer*>(system.DeviceMemory().GetPointer(phys_addr));
+    }
+};
+
+static_assert(sizeof(KPageBuffer) == PageSize);
+static_assert(alignof(KPageBuffer) == PageSize);
+
+} // namespace Kernel