Ported #4296 from citra

This will allow us to easily remove the use of "NFC" in "System"

src/core/hle/kernel/client_port.h

@@ -7,13 +7,13 @@
 #include <string>
 #include "common/common_types.h"
 #include "core/hle/kernel/object.h"
+#include "core/hle/kernel/server_port.h"
 #include "core/hle/result.h"
 
 namespace Kernel {
 
 class ClientSession;
 class KernelCore;
-class ServerPort;
 
 class ClientPort final : public Object {
 public:
@@ -30,6 +30,10 @@ public:
         return HANDLE_TYPE;
     }
 
+    SharedPtr<ServerPort> GetServerPort() const {
+        return server_port;
+    }
+
     /**
      * Creates a new Session pair, adds the created ServerSession to the associated ServerPort's
      * list of pending sessions, and signals the ServerPort, causing any threads

src/core/hle/kernel/server_port.h

@@ -11,6 +11,7 @@
 #include "common/common_types.h"
 #include "core/hle/kernel/object.h"
 #include "core/hle/kernel/wait_object.h"
+#include "core/hle/result.h"
 
 namespace Kernel {
 

src/core/hle/service/sm/sm.h

@@ -6,9 +6,12 @@
 
 #include <memory>
 #include <string>
+#include <type_traits>
 #include <unordered_map>
 
+#include "core/hle/kernel/client_port.h"
 #include "core/hle/kernel/object.h"
+#include "core/hle/kernel/server_port.h"
 #include "core/hle/result.h"
 #include "core/hle/service/service.h"
 
@@ -48,6 +51,22 @@ public:
     ResultVal<Kernel::SharedPtr<Kernel::ClientPort>> GetServicePort(const std::string& name);
     ResultVal<Kernel::SharedPtr<Kernel::ClientSession>> ConnectToService(const std::string& name);
 
+    template <typename T>
+    std::shared_ptr<T> GetService(const std::string& service_name) const {
+        static_assert(std::is_base_of_v<Kernel::SessionRequestHandler, T>,
+                      "Not a base of ServiceFrameworkBase");
+        auto service = registered_services.find(service_name);
+        if (service == registered_services.end()) {
+            LOG_DEBUG(Service, "Can't find service: {}", service_name);
+            return nullptr;
+        }
+        auto port = service->second->GetServerPort();
+        if (port == nullptr) {
+            return nullptr;
+        }
+        return std::static_pointer_cast<T>(port->hle_handler);
+    }
+
     void InvokeControlRequest(Kernel::HLERequestContext& context);
 
 private: