Move away from PCSX2 fastmem

third_party/host_memory/virtual_buffer.cpp

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <sys/mman.h>
+#endif
+
+#include "host_memory/virtual_buffer.h"
+
+namespace Common {
+
+void* AllocateMemoryPages(std::size_t size) noexcept {
+#ifdef _WIN32
+    void* base{VirtualAlloc(nullptr, size, MEM_COMMIT, PAGE_READWRITE)};
+#else
+    void* base{mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0)};
+
+    if (base == MAP_FAILED) {
+        base = nullptr;
+    }
+#endif
+
+    if (!base) {
+		Helpers::panic("Failed to allocate memory pages");
+    }
+
+    return base;
+}
+
+void FreeMemoryPages(void* base, [[maybe_unused]] std::size_t size) noexcept {
+    if (!base) {
+        return;
+    }
+#ifdef _WIN32
+	if (!VirtualFree(base, 0, MEM_RELEASE)) {
+		Helpers::panic("Failed to free memory pages");
+	}
+#else
+	if (munmap(base, size) != 0) {
+		Helpers::panic("Failed to free memory pages");
+    }
+#endif
+}
+
+} // namespace Common