From cb198d7985a4af00d9fdb656e9aeb16c158ce335 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Wed, 13 Mar 2019 03:09:27 -0400
Subject: core/hle/kernel: Split transfer memory handling out into its own
 class

Within the kernel, shared memory and transfer memory facilities exist as
completely different kernel objects. They also have different validity
checking as well. Therefore, we shouldn't be treating the two as the
same kind of memory.

They also differ in terms of their behavioral aspect as well. Shared
memory is intended for sharing memory between processes, while transfer
memory is intended to be for transferring memory to other processes.

This breaks out the handling for transfer memory into its own class and
treats it as its own kernel object. This is also important when we
consider resource limits as well. Particularly because transfer memory
is limited by the resource limit value set for it.

While we currently don't handle resource limit testing against objects
yet (but we do allow setting them), this will make implementing that
behavior much easier in the future, as we don't need to distinguish
between shared memory and transfer memory allocations in the same place.
---
 src/core/hle/kernel/transfer_memory.cpp | 73 +++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 src/core/hle/kernel/transfer_memory.cpp

(limited to 'src/core/hle/kernel/transfer_memory.cpp')

diff --git a/src/core/hle/kernel/transfer_memory.cpp b/src/core/hle/kernel/transfer_memory.cpp
new file mode 100644
index 000000000..23228e1b5
--- /dev/null
+++ b/src/core/hle/kernel/transfer_memory.cpp
@@ -0,0 +1,73 @@
+// Copyright 2019 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/hle/kernel/errors.h"
+#include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/process.h"
+#include "core/hle/kernel/shared_memory.h"
+#include "core/hle/kernel/transfer_memory.h"
+#include "core/hle/result.h"
+
+namespace Kernel {
+
+TransferMemory::TransferMemory(KernelCore& kernel) : Object{kernel} {}
+TransferMemory::~TransferMemory() = default;
+
+SharedPtr<TransferMemory> TransferMemory::Create(KernelCore& kernel, VAddr base_address,
+                                                 size_t size, MemoryPermission permissions) {
+    SharedPtr<TransferMemory> transfer_memory{new TransferMemory(kernel)};
+
+    transfer_memory->base_address = base_address;
+    transfer_memory->memory_size = size;
+    transfer_memory->owner_permissions = permissions;
+    transfer_memory->owner_process = kernel.CurrentProcess();
+
+    return transfer_memory;
+}
+
+ResultCode TransferMemory::MapMemory(VAddr address, size_t size, MemoryPermission permissions) {
+    if (memory_size != size) {
+        return ERR_INVALID_SIZE;
+    }
+
+    if (owner_permissions != permissions) {
+        return ERR_INVALID_STATE;
+    }
+
+    if (is_mapped) {
+        return ERR_INVALID_STATE;
+    }
+
+    const auto map_state = owner_permissions == MemoryPermission::None
+                               ? MemoryState::TransferMemoryIsolated
+                               : MemoryState::TransferMemory;
+    auto& vm_manager = owner_process->VMManager();
+    const auto map_result = vm_manager.MapMemoryBlock(
+        address, std::make_shared<std::vector<u8>>(size), 0, size, map_state);
+
+    if (map_result.Failed()) {
+        return map_result.Code();
+    }
+
+    is_mapped = true;
+    return RESULT_SUCCESS;
+}
+
+ResultCode TransferMemory::UnmapMemory(VAddr address, size_t size) {
+    if (memory_size != size) {
+        return ERR_INVALID_SIZE;
+    }
+
+    auto& vm_manager = owner_process->VMManager();
+    const auto result = vm_manager.UnmapRange(address, size);
+
+    if (result.IsError()) {
+        return result;
+    }
+
+    is_mapped = false;
+    return RESULT_SUCCESS;
+}
+
+} // namespace Kernel
-- 
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