From 06ea6cd46241c2f2b8488a980f9fb898331a214e Mon Sep 17 00:00:00 2001
From: Martin Stein <martin.stein@genode-labs.com>
Date: Sun, 16 Mar 2014 11:41:51 +0100
Subject: [PATCH] hw: simplify result of Kernel::access_thread_regs

ref #1101
---
 base-hw/src/core/kernel/core_interface.h | 20 +++++++++-----------
 base-hw/src/core/kernel/thread.cc        |  8 ++++----
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/base-hw/src/core/kernel/core_interface.h b/base-hw/src/core/kernel/core_interface.h
index ea8c78444..026cd6f7f 100644
--- a/base-hw/src/core/kernel/core_interface.h
+++ b/base-hw/src/core/kernel/core_interface.h
@@ -177,13 +177,11 @@ namespace Kernel
 	 * \param read_values   base of value buffer for read operations
 	 * \param write_values  base of value buffer for write operations
 	 *
-	 * \retval  0  all operations done
-	 * \retval >0  amount of undone operations
-	 * \retval -1  failed to start processing operations
+	 * \return  amount of undone operations according to the execution order
 	 *
-	 * Operations are processed in order of the appearance of the register
-	 * names in the callers UTCB. If reads = 0, read_values is of no relevance.
-	 * If writes = 0, write_values is of no relevance.
+	 * Operations are executed in order of the appearance of the register names
+	 * in the callers UTCB. If reads = 0, read_values is of no relevance. If
+	 * writes = 0, write_values is of no relevance.
 	 *
 	 * Expected structure at the callers UTCB base:
 	 *
@@ -200,11 +198,11 @@ namespace Kernel
 	 *                  ...                   ...
 	 *         (writes - 1) * sizeof(addr_t): write value #writes
 	 */
-	inline int access_thread_regs(unsigned const thread_id,
-	                              unsigned const reads,
-	                              unsigned const writes,
-	                              addr_t * const read_values,
-	                              addr_t * const write_values)
+	inline unsigned access_thread_regs(unsigned const thread_id,
+	                                   unsigned const reads,
+	                                   unsigned const writes,
+	                                   addr_t * const read_values,
+	                                   addr_t * const write_values)
 	{
 		return call(call_id_access_thread_regs(), thread_id, reads, writes,
 		            (Call_arg)read_values, (Call_arg)write_values);
diff --git a/base-hw/src/core/kernel/thread.cc b/base-hw/src/core/kernel/thread.cc
index a9360f30e..b16b4ad88 100644
--- a/base-hw/src/core/kernel/thread.cc
+++ b/base-hw/src/core/kernel/thread.cc
@@ -553,9 +553,11 @@ unsigned Thread_event::signal_context_id() const
 void Thread::_call_access_thread_regs()
 {
 	/* check permissions */
+	unsigned const reads = user_arg_2();
+	unsigned const writes = user_arg_3();
 	if (!_core()) {
 		PWRN("not entitled to access thread regs");
-		user_arg_0(-1);
+		user_arg_0(reads + writes);
 		return;
 	}
 	/* get targeted thread */
@@ -563,12 +565,10 @@ void Thread::_call_access_thread_regs()
 	Thread * const t = Thread::pool()->object(thread_id);
 	if (!t) {
 		PWRN("unknown thread");
-		user_arg_0(-1);
+		user_arg_0(reads + writes);
 		return;
 	}
 	/* execute read operations */
-	unsigned const reads = user_arg_2();
-	unsigned const writes = user_arg_3();
 	addr_t * const utcb = (addr_t *)_utcb_phys->base();
 	addr_t * const read_ids = &utcb[0];
 	addr_t * const read_values = (addr_t *)user_arg_4();