service/apm: Add the apm:sys service

Adds the basic skeleton of the apm:sys service based off the information
on Switch Brew.

src/core/hle/kernel/client_port.cpp

@@ -14,8 +14,8 @@
 
 namespace Kernel {
 
-ClientPort::ClientPort() = default;
-ClientPort::~ClientPort() = default;
+ClientPort::ClientPort() {}
+ClientPort::~ClientPort() {}
 
 ResultVal<SharedPtr<ClientSession>> ClientPort::Connect() {
     // Note: Threads do not wait for the server endpoint to call
@@ -40,12 +40,4 @@ ResultVal<SharedPtr<ClientSession>> ClientPort::Connect() {
     return MakeResult(std::get<SharedPtr<ClientSession>>(sessions));
 }
 
-void ClientPort::ConnectionClosed() {
-    if (active_sessions == 0) {
-        return;
-    }
-
-    --active_sessions;
-}
-
 } // namespace Kernel

src/core/hle/kernel/client_port.h

@@ -37,20 +37,14 @@ public:
      */
     ResultVal<SharedPtr<ClientSession>> Connect();
 
-    /**
-     * Signifies that a previously active connection has been closed,
-     * decreasing the total number of active connections to this port.
-     */
-    void ConnectionClosed();
+    SharedPtr<ServerPort> server_port; ///< ServerPort associated with this client port.
+    u32 max_sessions;    ///< Maximum number of simultaneous sessions the port can have
+    u32 active_sessions; ///< Number of currently open sessions to this port
+    std::string name;    ///< Name of client port (optional)
 
 private:
     ClientPort();
     ~ClientPort() override;
-
-    SharedPtr<ServerPort> server_port; ///< ServerPort associated with this client port.
-    u32 max_sessions = 0;    ///< Maximum number of simultaneous sessions the port can have
-    u32 active_sessions = 0; ///< Number of currently open sessions to this port
-    std::string name;        ///< Name of client port (optional)
 };
 
 } // namespace Kernel

src/core/hle/kernel/server_session.cpp

@@ -27,7 +27,7 @@ ServerSession::~ServerSession() {
 
     // Decrease the port's connection count.
     if (parent->port)
-        parent->port->ConnectionClosed();
+        parent->port->active_sessions--;
 
     // TODO(Subv): Wake up all the ClientSession's waiting threads and set
     // the SendSyncRequest result to 0xC920181A.

src/core/hle/service/apm/apm.cpp

@@ -13,6 +13,7 @@ void InstallInterfaces(SM::ServiceManager& service_manager) {
     auto module_ = std::make_shared<Module>();
     std::make_shared<APM>(module_, "apm")->InstallAsService(service_manager);
     std::make_shared<APM>(module_, "apm:p")->InstallAsService(service_manager);
+    std::make_shared<APM_Sys>()->InstallAsService(service_manager);
 }
 
 } // namespace Service::APM

src/core/hle/service/apm/interface.cpp

@@ -74,6 +74,31 @@ void APM::OpenSession(Kernel::HLERequestContext& ctx) {
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
     rb.PushIpcInterface<ISession>();
+
+    LOG_DEBUG(Service_APM, "called");
+}
+
+APM_Sys::APM_Sys() : ServiceFramework{"apm:sys"} {
+    // clang-format off
+    static const FunctionInfo functions[] = {
+        {0, nullptr, "RequestPerformanceMode"},
+        {1, &APM_Sys::GetPerformanceEvent, "GetPerformanceEvent"},
+        {2, nullptr, "GetThrottlingState"},
+        {3, nullptr, "GetLastThrottlingState"},
+        {4, nullptr, "ClearLastThrottlingState"},
+        {5, nullptr, "LoadAndApplySettings"},
+    };
+    // clang-format on
+
+    RegisterHandlers(functions);
+}
+
+void APM_Sys::GetPerformanceEvent(Kernel::HLERequestContext& ctx) {
+    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+    rb.Push(RESULT_SUCCESS);
+    rb.PushIpcInterface<ISession>();
+
+    LOG_DEBUG(Service_APM, "called");
 }
 
 } // namespace Service::APM

src/core/hle/service/apm/interface.h

@@ -19,4 +19,12 @@ private:
     std::shared_ptr<Module> apm;
 };
 
+class APM_Sys final : public ServiceFramework<APM_Sys> {
+public:
+    explicit APM_Sys();
+
+private:
+    void GetPerformanceEvent(Kernel::HLERequestContext& ctx);
+};
+
 } // namespace Service::APM