From a7837a3791562899bf5e0e98aef851a2f4aaf376 Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Sat, 5 Jun 2021 06:23:25 -0300
Subject: common/host_memory: Add interface and Windows implementation

---
 src/common/host_memory.h | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 src/common/host_memory.h

(limited to 'src/common/host_memory.h')

diff --git a/src/common/host_memory.h b/src/common/host_memory.h
new file mode 100644
index 000000000..98005df7a
--- /dev/null
+++ b/src/common/host_memory.h
@@ -0,0 +1,62 @@
+// Copyright 2019 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include "common/common_types.h"
+
+namespace Common {
+
+/**
+ * A low level linear memory buffer, which supports multiple mappings
+ * Its purpose is to rebuild a given sparse memory layout, including mirrors.
+ */
+class HostMemory {
+public:
+    explicit HostMemory(size_t backing_size, size_t virtual_size);
+    ~HostMemory();
+
+    /**
+     * Copy constructors. They shall return a copy of the buffer without the mappings.
+     * TODO: Implement them with COW if needed.
+     */
+    HostMemory(const HostMemory& other) = delete;
+    HostMemory& operator=(const HostMemory& other) = delete;
+
+    /**
+     * Move constructors. They will move the buffer and the mappings to the new object.
+     */
+    HostMemory(HostMemory&& other) noexcept;
+    HostMemory& operator=(HostMemory&& other) noexcept;
+
+    void Map(size_t virtual_offset, size_t host_offset, size_t length);
+
+    void Unmap(size_t virtual_offset, size_t length);
+
+    void Protect(size_t virtual_offset, size_t length, bool read, bool write);
+
+    [[nodiscard]] u8* BackingBasePointer() noexcept {
+        return backing_base;
+    }
+    [[nodiscard]] const u8* BackingBasePointer() const noexcept {
+        return backing_base;
+    }
+
+    [[nodiscard]] u8* VirtualBasePointer() noexcept {
+        return virtual_base;
+    }
+    [[nodiscard]] const u8* VirtualBasePointer() const noexcept {
+        return virtual_base;
+    }
+
+private:
+    // Low level handler for the platform dependent memory routines
+    class Impl;
+    std::unique_ptr<Impl> impl;
+    u8* backing_base{};
+    u8* virtual_base{};
+};
+
+} // namespace Common
-- 
cgit v1.2.3


From c4609c92eea30558473f02082733c7e59c2d2013 Mon Sep 17 00:00:00 2001
From: Markus Wick <markus@selfnet.de>
Date: Sat, 5 Jun 2021 11:47:08 +0200
Subject: common/host_memory: Optimize for huge tables.

In theory, if we have 2 MB continously mapped, this should save one layer of TLB.
Let's make it at least more likely by aligning the memory.
---
 src/common/host_memory.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

(limited to 'src/common/host_memory.h')

diff --git a/src/common/host_memory.h b/src/common/host_memory.h
index 98005df7a..eaa7d18ab 100644
--- a/src/common/host_memory.h
+++ b/src/common/host_memory.h
@@ -15,7 +15,7 @@ namespace Common {
  */
 class HostMemory {
 public:
-    explicit HostMemory(size_t backing_size, size_t virtual_size);
+    explicit HostMemory(size_t backing_size_, size_t virtual_size_);
     ~HostMemory();
 
     /**
@@ -52,11 +52,15 @@ public:
     }
 
 private:
+    size_t backing_size{};
+    size_t virtual_size{};
+
     // Low level handler for the platform dependent memory routines
     class Impl;
     std::unique_ptr<Impl> impl;
     u8* backing_base{};
     u8* virtual_base{};
+    size_t virtual_base_offset{};
 };
 
 } // namespace Common
-- 
cgit v1.2.3


From 7f85abb28120fbb57bb813b828ee42f2a2031990 Mon Sep 17 00:00:00 2001
From: Markus Wick <markus@selfnet.de>
Date: Fri, 11 Jun 2021 11:47:23 +0200
Subject: common/host_memory: Implement a fallback if fastmem fails.

This falls back to the old approach of using a virtual buffer.

Windows is untested, but this build should fix support for Windows < 10 v1803. However without fastmem support at all.
---
 src/common/host_memory.h | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'src/common/host_memory.h')

diff --git a/src/common/host_memory.h b/src/common/host_memory.h
index eaa7d18ab..9b8326d0f 100644
--- a/src/common/host_memory.h
+++ b/src/common/host_memory.h
@@ -6,6 +6,7 @@
 
 #include <memory>
 #include "common/common_types.h"
+#include "common/virtual_buffer.h"
 
 namespace Common {
 
@@ -61,6 +62,9 @@ private:
     u8* backing_base{};
     u8* virtual_base{};
     size_t virtual_base_offset{};
+
+    // Fallback if fastmem is not supported on this platform
+    std::unique_ptr<Common::VirtualBuffer<u8>> fallback_buffer;
 };
 
 } // namespace Common
-- 
cgit v1.2.3