1 files changed, 118 insertions, 0 deletions
diff --git a/src/core/hle/kernel/memory/address_space_info.cpp b/src/core/hle/kernel/memory/address_space_info.cpp
new file mode 100644
index 000000000..27fae05e7
--- /dev/null
+++ b/src/core/hle/kernel/memory/address_space_info.cpp
@@ -0,0 +1,118 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+// This file references various implementation details from Atmosphère, an open-source firmware for
+// the Nintendo Switch. Copyright 2018-2020 Atmosphère-NX.
+
+#include <array>
+
+#include "common/assert.h"
+#include "core/hle/kernel/memory/address_space_info.h"
+
+namespace Kernel::Memory {
+
+namespace {
+
+enum : u64 {
+    Size_1_MB = 0x100000,
+    Size_2_MB = 2 * Size_1_MB,
+    Size_128_MB = 128 * Size_1_MB,
+    Size_1_GB = 0x40000000,
+    Size_2_GB = 2 * Size_1_GB,
+    Size_4_GB = 4 * Size_1_GB,
+    Size_6_GB = 6 * Size_1_GB,
+    Size_64_GB = 64 * Size_1_GB,
+    Size_512_GB = 512 * Size_1_GB,
+    Invalid = std::numeric_limits<u64>::max(),
+};
+
+// clang-format off
+constexpr std::array<AddressSpaceInfo, 13> AddressSpaceInfos{{
+   { 32 /*bit_width*/, Size_2_MB   /*addr*/, Size_1_GB   - Size_2_MB   /*size*/, AddressSpaceInfo::Type::Is32Bit,    },
+   { 32 /*bit_width*/, Size_1_GB   /*addr*/, Size_4_GB   - Size_1_GB   /*size*/, AddressSpaceInfo::Type::Small64Bit, },
+   { 32 /*bit_width*/, Invalid     /*addr*/, Size_1_GB                 /*size*/, AddressSpaceInfo::Type::Heap,       },
+   { 32 /*bit_width*/, Invalid     /*addr*/, Size_1_GB                 /*size*/, AddressSpaceInfo::Type::Alias,      },
+   { 36 /*bit_width*/, Size_128_MB /*addr*/, Size_2_GB   - Size_128_MB /*size*/, AddressSpaceInfo::Type::Is32Bit,    },
+   { 36 /*bit_width*/, Size_2_GB   /*addr*/, Size_64_GB  - Size_2_GB   /*size*/, AddressSpaceInfo::Type::Small64Bit, },
+   { 36 /*bit_width*/, Invalid     /*addr*/, Size_6_GB                 /*size*/, AddressSpaceInfo::Type::Heap,       },
+   { 36 /*bit_width*/, Invalid     /*addr*/, Size_6_GB                 /*size*/, AddressSpaceInfo::Type::Alias,      },
+   { 39 /*bit_width*/, Size_128_MB /*addr*/, Size_512_GB - Size_128_MB /*size*/, AddressSpaceInfo::Type::Large64Bit, },
+   { 39 /*bit_width*/, Invalid     /*addr*/, Size_64_GB                /*size*/, AddressSpaceInfo::Type::Is32Bit     },
+   { 39 /*bit_width*/, Invalid     /*addr*/, Size_6_GB                 /*size*/, AddressSpaceInfo::Type::Heap,       },
+   { 39 /*bit_width*/, Invalid     /*addr*/, Size_64_GB                /*size*/, AddressSpaceInfo::Type::Alias,      },
+   { 39 /*bit_width*/, Invalid     /*addr*/, Size_2_GB                 /*size*/, AddressSpaceInfo::Type::Stack,      },
+}};
+// clang-format on
+
+constexpr bool IsAllowedIndexForAddress(std::size_t index) {
+    return index < std::size(AddressSpaceInfos) && AddressSpaceInfos[index].GetAddress() != Invalid;
+}
+
+constexpr std::size_t
+    AddressSpaceIndices32Bit[static_cast<std::size_t>(AddressSpaceInfo::Type::Count)]{
+        0, 1, 0, 2, 0, 3,
+    };
+
+constexpr std::size_t
+    AddressSpaceIndices36Bit[static_cast<std::size_t>(AddressSpaceInfo::Type::Count)]{
+        4, 5, 4, 6, 4, 7,
+    };
+
+constexpr std::size_t
+    AddressSpaceIndices39Bit[static_cast<std::size_t>(AddressSpaceInfo::Type::Count)]{
+        9, 8, 8, 10, 12, 11,
+    };
+
+constexpr bool IsAllowed32BitType(AddressSpaceInfo::Type type) {
+    return type < AddressSpaceInfo::Type::Count && type != AddressSpaceInfo::Type::Large64Bit &&
+           type != AddressSpaceInfo::Type::Stack;
+}
+
+constexpr bool IsAllowed36BitType(AddressSpaceInfo::Type type) {
+    return type < AddressSpaceInfo::Type::Count && type != AddressSpaceInfo::Type::Large64Bit &&
+           type != AddressSpaceInfo::Type::Stack;
+}
+
+constexpr bool IsAllowed39BitType(AddressSpaceInfo::Type type) {
+    return type < AddressSpaceInfo::Type::Count && type != AddressSpaceInfo::Type::Small64Bit;
+}
+
+} // namespace
+
+u64 AddressSpaceInfo::GetAddressSpaceStart(std::size_t width, AddressSpaceInfo::Type type) {
+    const std::size_t index{static_cast<std::size_t>(type)};
+    switch (width) {
+    case 32:
+        ASSERT(IsAllowed32BitType(type));
+        ASSERT(IsAllowedIndexForAddress(AddressSpaceIndices32Bit[index]));
+        return AddressSpaceInfos[AddressSpaceIndices32Bit[index]].GetAddress();
+    case 36:
+        ASSERT(IsAllowed36BitType(type));
+        ASSERT(IsAllowedIndexForAddress(AddressSpaceIndices36Bit[index]));
+        return AddressSpaceInfos[AddressSpaceIndices36Bit[index]].GetAddress();
+    case 39:
+        ASSERT(IsAllowed39BitType(type));
+        ASSERT(IsAllowedIndexForAddress(AddressSpaceIndices39Bit[index]));
+        return AddressSpaceInfos[AddressSpaceIndices39Bit[index]].GetAddress();
+    }
+    UNREACHABLE();
+}
+
+std::size_t AddressSpaceInfo::GetAddressSpaceSize(std::size_t width, AddressSpaceInfo::Type type) {
+    const std::size_t index{static_cast<std::size_t>(type)};
+    switch (width) {
+    case 32:
+        ASSERT(IsAllowed32BitType(type));
+        return AddressSpaceInfos[AddressSpaceIndices32Bit[index]].GetSize();
+    case 36:
+        ASSERT(IsAllowed36BitType(type));
+        return AddressSpaceInfos[AddressSpaceIndices36Bit[index]].GetSize();
+    case 39:
+        ASSERT(IsAllowed39BitType(type));
+        return AddressSpaceInfos[AddressSpaceIndices39Bit[index]].GetSize();
+    }
+    UNREACHABLE();
+}
+
+} // namespace Kernel::Memory