sapi: SMP support for chains

Add ISR lock to chain control for proper SMP protection.  Replace
rtems_chain_extract() with rtems_chain_explicit_extract() and
rtems_chain_insert() with rtems_chain_explicit_insert() on SMP
configurations.  Use rtems_chain_explicit_extract() and
rtems_chain_explicit_insert() to provide SMP support.

1 files changed, 138 insertions, 0 deletions

diff --git a/cpukit/sapi/src/chainsmp.c b/cpukit/sapi/src/chainsmp.c
new file mode 100644
index 0000000000..ea8de83a0b
--- /dev/null
+++ b/cpukit/sapi/src/chainsmp.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2013 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/chain.h>
+
+#if defined( RTEMS_SMP )
+
+void rtems_chain_explicit_extract(
+  rtems_chain_control *chain,
+  rtems_chain_node *node
+)
+{
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  _Chain_Extract_unprotected( node );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+}
+
+rtems_chain_node *rtems_chain_get( rtems_chain_control *chain )
+{
+  rtems_chain_node *node;
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  node = _Chain_Get_unprotected( &chain->Chain );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+
+  return node;
+}
+
+void rtems_chain_explicit_insert(
+  rtems_chain_control *chain,
+  rtems_chain_node *after_node,
+  rtems_chain_node *node
+)
+{
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  _Chain_Insert_unprotected( after_node, node );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+}
+
+void rtems_chain_append(
+  rtems_chain_control *chain,
+  rtems_chain_node *node
+)
+{
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  _Chain_Append_unprotected( &chain->Chain, node );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+}
+
+void rtems_chain_prepend(
+  rtems_chain_control *chain,
+  rtems_chain_node *node
+)
+{
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  _Chain_Prepend_unprotected( &chain->Chain, node );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+}
+
+bool rtems_chain_append_with_empty_check(
+  rtems_chain_control *chain,
+  rtems_chain_node *node
+)
+{
+  bool was_empty;
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  was_empty = _Chain_Append_with_empty_check_unprotected(
+    &chain->Chain,
+    node
+  );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+
+  return was_empty;
+}
+
+bool rtems_chain_prepend_with_empty_check(
+  rtems_chain_control *chain,
+  rtems_chain_node *node
+)
+{
+  bool was_empty;
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  was_empty = _Chain_Prepend_with_empty_check_unprotected(
+    &chain->Chain,
+    node
+  );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+
+  return was_empty;
+}
+
+bool rtems_chain_get_with_empty_check(
+  rtems_chain_control *chain,
+  rtems_chain_node **node
+)
+{
+  bool is_empty_now;
+  ISR_Level level;
+
+  _ISR_lock_ISR_disable_and_acquire( &chain->Lock, level );
+  is_empty_now = _Chain_Get_with_empty_check_unprotected(
+    &chain->Chain,
+    node
+  );
+  _ISR_lock_Release_and_ISR_enable( &chain->Lock, level );
+
+  return is_empty_now;
+}
+
+#endif /* defined( RTEMS_SMP ) */