From 847c8cccd986996959688f6626850ac8ebc5698a Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Wed, 25 Jul 2012 13:59:50 +0200
Subject: [PATCH] Add 'Timer::Session::elapsed_ms' function

This function allows a timer-session client to request a wall-clock
time value from the timer.
---
 os/include/timer_session/client.h             |  2 ++
 os/include/timer_session/timer_session.h      | 14 +++++++++++++-
 .../timer/foc/timer_session_component.h       | 19 ++++++++++++++++---
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/os/include/timer_session/client.h b/os/include/timer_session/client.h
index 2806632d7..1a240f59e 100644
--- a/os/include/timer_session/client.h
+++ b/os/include/timer_session/client.h
@@ -25,6 +25,8 @@ namespace Timer {
 		: Genode::Rpc_client<Session>(session) { }
 
 		void msleep(unsigned ms) { call<Rpc_msleep>(ms); }
+
+		unsigned long elapsed_ms() const { return call<Rpc_elapsed_ms>(); }
 	};
 }
 
diff --git a/os/include/timer_session/timer_session.h b/os/include/timer_session/timer_session.h
index 9d160243d..58e9cac41 100644
--- a/os/include/timer_session/timer_session.h
+++ b/os/include/timer_session/timer_session.h
@@ -29,14 +29,26 @@ namespace Timer {
 		 */
 		virtual void msleep(unsigned ms) = 0;
 
+		/**
+		 * Return number of elapsed milliseconds since session creation
+		 */
+		virtual unsigned long elapsed_ms() const
+		{
+			/*
+			 * XXX Remove default implementation by implementing the
+			 *     interface in all timer variants.
+			 */
+			return 0; }
+
 
 		/*********************
 		 ** RPC declaration **
 		 *********************/
 
 		GENODE_RPC(Rpc_msleep, void, msleep, unsigned);
+		GENODE_RPC(Rpc_elapsed_ms, unsigned long, elapsed_ms);
 
-		GENODE_RPC_INTERFACE(Rpc_msleep);
+		GENODE_RPC_INTERFACE(Rpc_msleep, Rpc_elapsed_ms);
 	};
 }
 
diff --git a/os/src/drivers/timer/foc/timer_session_component.h b/os/src/drivers/timer/foc/timer_session_component.h
index 9f9812c86..761f34322 100644
--- a/os/src/drivers/timer/foc/timer_session_component.h
+++ b/os/src/drivers/timer/foc/timer_session_component.h
@@ -18,10 +18,12 @@
 /* Genode includes */
 #include <base/rpc_server.h>
 #include <timer_session/capability.h>
+#include <os/attached_rom_dataspace.h>
 
 /* Fiasco.OC includes */
 namespace Fiasco {
 #include <l4/sys/ipc.h>
+#include <l4/sys/kip.h>
 }
 
 
@@ -63,8 +65,11 @@ namespace Timer {
 	{
 		private:
 
-			Genode::Rpc_entrypoint _entrypoint;
-			Session_capability     _session_cap;
+			Genode::Rpc_entrypoint           _entrypoint;
+			Session_capability               _session_cap;
+			Genode::Attached_rom_dataspace   _kip_ds;
+			Fiasco::l4_kernel_info_t * const _kip;
+			Fiasco::l4_cpu_time_t const      _initial_clock_value;
 
 		public:
 
@@ -74,7 +79,10 @@ namespace Timer {
 			Session_component(Genode::Cap_session *cap)
 			:
 				_entrypoint(cap, STACK_SIZE, "timer_session_ep"),
-				_session_cap(_entrypoint.manage(this))
+				_session_cap(_entrypoint.manage(this)),
+				_kip_ds("l4v2_kip"),
+				_kip(_kip_ds.local_addr<Fiasco::l4_kernel_info_t>()),
+				_initial_clock_value(_kip->clock)
 			{ }
 
 			/**
@@ -109,6 +117,11 @@ namespace Timer {
 
 				l4_ipc_sleep(l4_timeout(L4_IPC_TIMEOUT_NEVER, mus_to_timeout(1000*ms)));
 			}
+
+			unsigned long elapsed_ms() const
+			{
+				return (_kip->clock - _initial_clock_value) / 1000;
+			}
 	};
 }