posix: Add self-contained pthread spinlock

Turn pthread_spinlock_t into a self-contained object.  On uni-processor
configurations, interrupts are disabled in the lock/trylock operations
and the previous interrupt status is restored in the corresponding
unlock operations.  On SMP configurations, a ticket lock is a acquired
and released in addition.

The self-contained pthread_spinlock_t object is defined by Newlib in
<sys/_pthreadtypes.h>.

typedef struct {
  struct _Ticket_lock_Control _lock;
  __uint32_t                  _interrupt_state;
} pthread_spinlock_t;

This implementation is simple and efficient.  However, this test case of
the Linux Test Project would fail due to call of printf() and sleep()
during spin lock ownership:

https://github.com/linux-test-project/ltp/blob/master/testcases/open_posix_testsuite/conformance/interfaces/pthread_spin_lock/1-2.c

There is only limited support for profiling on SMP configurations.

Delete CORE spinlock implementation.

Update #2674.

11 files changed, 171 insertions, 312 deletions

diff --git a/cpukit/posix/Makefile.am b/cpukit/posix/Makefile.am
index 5bf11c7713..d9a3437b13 100644
--- a/cpukit/posix/Makefile.am
+++ b/cpukit/posix/Makefile.am
@@ -21,6 +21,7 @@ include_rtems_posix_HEADERS += include/rtems/posix/keyimpl.h
 include_rtems_posix_HEADERS += include/rtems/posix/config.h
 include_rtems_posix_HEADERS += include/rtems/posix/posixapi.h
 include_rtems_posix_HEADERS += include/rtems/posix/priorityimpl.h
+include_rtems_posix_HEADERS += include/rtems/posix/spinlockimpl.h
 
 if HAS_PTHREADS
 # include
@@ -52,8 +53,6 @@ include_rtems_posix_HEADERS += include/rtems/posix/barrier.h
 include_rtems_posix_HEADERS += include/rtems/posix/barrierimpl.h
 include_rtems_posix_HEADERS += include/rtems/posix/rwlock.h
 include_rtems_posix_HEADERS += include/rtems/posix/rwlockimpl.h
-include_rtems_posix_HEADERS += include/rtems/posix/spinlock.h
-include_rtems_posix_HEADERS += include/rtems/posix/spinlockimpl.h
 
 ## src
 libposix_a_SOURCES += src/aio_cancel.c src/aio_error.c src/aio_fsync.c \
@@ -168,6 +167,12 @@ libposix_a_SOURCES += src/sigaddset.c src/sigdelset.c src/sigfillset.c \
 
 libposix_a_SOURCES += src/sigprocmask.c
 
+## SPINLOCK_C_FILES
+libposix_a_SOURCES += src/pspindestroy.c
+libposix_a_SOURCES += src/pspininit.c
+libposix_a_SOURCES += src/pspinlock.c
+libposix_a_SOURCES += src/pspinunlock.c
+
 if HAS_PTHREADS
 libposix_a_SOURCES += src/sigpending.c \
     src/sigqueue.c src/sigsuspend.c src/sigtimedwait.c \
@@ -188,11 +193,6 @@ libposix_a_SOURCES += src/semaphore.c src/semaphorecreatesupp.c \
     src/semopen.c src/sempost.c src/semtimedwait.c src/semtrywait.c \
     src/semunlink.c src/semwait.c
 
-## SPINLOCK_C_FILES
-libposix_a_SOURCES += src/pspin.c src/pspindestroy.c src/pspininit.c \
-    src/pspinlock.c src/pspintrylock.c \
-    src/pspinunlock.c
-
 ## TIME_C_FILES
 libposix_a_SOURCES += src/adjtime.c src/clockgetcpuclockid.c
 
diff --git a/cpukit/posix/include/rtems/posix/config.h b/cpukit/posix/include/rtems/posix/config.h
index 636f1e7d79..11c73c2b2f 100644
--- a/cpukit/posix/include/rtems/posix/config.h
+++ b/cpukit/posix/include/rtems/posix/config.h
@@ -111,12 +111,6 @@ typedef struct {
   uint32_t                            maximum_rwlocks;
 
   /**
-   * This field contains the maximum number of POSIX API
-   * spinlocks which are configured for this application.
-   */
-  uint32_t                            maximum_spinlocks;
-
-  /**
    * This field contains the number of POSIX API Initialization
    * threads listed in @a User_initialization_thread_table.
    */
diff --git a/cpukit/posix/include/rtems/posix/spinlock.h b/cpukit/posix/include/rtems/posix/spinlock.h
deleted file mode 100644
index 8da451ce22..0000000000
--- a/cpukit/posix/include/rtems/posix/spinlock.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/**
- * @file
- * 
- * @brief POSIX Spinlock Support
- *
- * This include file contains all the constants and structures associated
- * with the POSIX Spinlock Manager.
- *
- *  Directives provided are:
- *
- *   - create a spinlock
- *   - delete a spinlock
- *   - wait for a spinlock
- */
-
-/*
- *  COPYRIGHT (c) 1989-2011.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
- */
-
-#ifndef _RTEMS_POSIX_SPINLOCK_H
-#define _RTEMS_POSIX_SPINLOCK_H
-
-#include <rtems/score/object.h>
-#include <rtems/score/corespinlock.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
- * @defgroup POSIX_SPINLOCK POSIX Spinlock Support
- *
- * @ingroup POSIXAPI
- *
- * @brief Constants and Structures Associated with the POSIX Spinlock Manager
- * 
- */
-/**@{**/
-
-/**
- * This type defines the control block used to manage each spinlock.
- */
-
-typedef struct {
-  /** This is used to manage a spinlock as an object. */
-  Objects_Control          Object;
-  /** This is used to implement the spinlock. */
-  CORE_spinlock_Control    Spinlock;
-}   POSIX_Spinlock_Control;
-
-/** @} */
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
-/*  end of include file */
diff --git a/cpukit/posix/include/rtems/posix/spinlockimpl.h b/cpukit/posix/include/rtems/posix/spinlockimpl.h
index f1b5639bd1..36ef6677a0 100644
--- a/cpukit/posix/include/rtems/posix/spinlockimpl.h
+++ b/cpukit/posix/include/rtems/posix/spinlockimpl.h
@@ -11,6 +11,8 @@
  *  COPYRIGHT (c) 1989-2011.
  *  On-Line Applications Research Corporation (OAR).
  *
+ *  Copyright (c) 2016 embedded brains GmbH
+ *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
  *  http://www.rtems.org/license/LICENSE.
@@ -19,62 +21,55 @@
 #ifndef _RTEMS_POSIX_SPINLOCKIMPL_H
 #define _RTEMS_POSIX_SPINLOCKIMPL_H
 
-#include <rtems/posix/spinlock.h>
-#include <rtems/score/corespinlockimpl.h>
-#include <rtems/score/objectimpl.h>
-
 #include <pthread.h>
 
+#include <rtems/score/isrlevel.h>
+
+#if defined(RTEMS_SMP)
+#include <rtems/score/percpu.h>
+#include <rtems/score/smplockticket.h>
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/**
- * The following defines the information control block used to manage
- * this class of objects.
- */
+#if SIZEOF_PTHREAD_SPINLOCK_T > 4
+#define POSIX_SPINLOCKS_ARE_SELF_CONTAINED
+#endif
 
-extern Objects_Information _POSIX_Spinlock_Information;
+typedef struct {
+#if defined(RTEMS_SMP)
+  SMP_ticket_lock_Control Lock;
+#else
+  unsigned int reserved[ 2 ];
+#endif
+  ISR_Level interrupt_state;
+} POSIX_Spinlock_Control;
 
-/**
- * @brief Allocate a spinlock control block.
- *
- * This function allocates a spinlock control block from
- * the inactive chain of free spinlock control blocks.
- */
-RTEMS_INLINE_ROUTINE POSIX_Spinlock_Control *_POSIX_Spinlock_Allocate( void )
-{
-  return (POSIX_Spinlock_Control *) 
-    _Objects_Allocate( &_POSIX_Spinlock_Information );
-}
+#if !defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+#if defined(RTEMS_SMP)
+extern POSIX_Spinlock_Control _POSIX_Spinlock_Global;
 
-/**
- * @brief Free a spinlock control block.
- *
- * This routine frees a spinlock control block to the
- * inactive chain of free spinlock control blocks.
- */
-RTEMS_INLINE_ROUTINE void _POSIX_Spinlock_Free (
-  POSIX_Spinlock_Control *the_spinlock
-)
-{
-  _Objects_Free( &_POSIX_Spinlock_Information, &the_spinlock->Object );
-}
+extern uint32_t _POSIX_Spinlock_Owner;
+#endif
+
+extern int _POSIX_Spinlock_Nest_level;
+#endif
 
 RTEMS_INLINE_ROUTINE POSIX_Spinlock_Control *_POSIX_Spinlock_Get(
-  pthread_spinlock_t *spinlock,
-  ISR_lock_Context   *lock_context
+  pthread_spinlock_t *lock
 )
 {
-  if ( spinlock == NULL ) {
-    return NULL;
-  }
-
-  return (POSIX_Spinlock_Control *) _Objects_Get(
-    *spinlock,
-    lock_context,
-    &_POSIX_Spinlock_Information
-  );
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+  return (POSIX_Spinlock_Control *) lock;
+#elif defined(RTEMS_SMP)
+  (void) lock;
+  return &_POSIX_Spinlock_Global;
+#else
+  (void) lock;
+  return NULL;
+#endif
 }
 
 #ifdef __cplusplus
diff --git a/cpukit/posix/preinstall.am b/cpukit/posix/preinstall.am
index 1d035e7425..4f1b220fe1 100644
--- a/cpukit/posix/preinstall.am
+++ b/cpukit/posix/preinstall.am
@@ -47,6 +47,10 @@ $(PROJECT_INCLUDE)/rtems/posix/priorityimpl.h: include/rtems/posix/priorityimpl.
 	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/posix/priorityimpl.h
 PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/posix/priorityimpl.h
 
+$(PROJECT_INCLUDE)/rtems/posix/spinlockimpl.h: include/rtems/posix/spinlockimpl.h $(PROJECT_INCLUDE)/rtems/posix/$(dirstamp)
+	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/posix/spinlockimpl.h
+PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/posix/spinlockimpl.h
+
 if HAS_PTHREADS
 $(PROJECT_INCLUDE)/aio.h: include/aio.h $(PROJECT_INCLUDE)/$(dirstamp)
 	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/aio.h
@@ -144,14 +148,6 @@ PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/posix/rwlock.h
 $(PROJECT_INCLUDE)/rtems/posix/rwlockimpl.h: include/rtems/posix/rwlockimpl.h $(PROJECT_INCLUDE)/rtems/posix/$(dirstamp)
 	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/posix/rwlockimpl.h
 PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/posix/rwlockimpl.h
-
-$(PROJECT_INCLUDE)/rtems/posix/spinlock.h: include/rtems/posix/spinlock.h $(PROJECT_INCLUDE)/rtems/posix/$(dirstamp)
-	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/posix/spinlock.h
-PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/posix/spinlock.h
-
-$(PROJECT_INCLUDE)/rtems/posix/spinlockimpl.h: include/rtems/posix/spinlockimpl.h $(PROJECT_INCLUDE)/rtems/posix/$(dirstamp)
-	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/rtems/posix/spinlockimpl.h
-PREINSTALL_FILES += $(PROJECT_INCLUDE)/rtems/posix/spinlockimpl.h
 endif
 if HAS_PTHREADS
 endif
diff --git a/cpukit/posix/src/pspin.c b/cpukit/posix/src/pspin.c
deleted file mode 100644
index 6c466bcab5..0000000000
--- a/cpukit/posix/src/pspin.c
+++ /dev/null
@@ -1,51 +0,0 @@
-/**
- *  @file
- *
- *  This file contains the initialization of the POSIX Spinlock Manager.
- */
-
-/*
- *  COPYRIGHT (c) 1989-2013.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include <limits.h>
-
-#include <rtems/system.h>
-#include <rtems/config.h>
-#include <rtems/sysinit.h>
-#include <rtems/posix/spinlockimpl.h>
-
-Objects_Information _POSIX_Spinlock_Information;
-
-/**
- *  @brief _POSIX_Spinlock_Manager_initialization
- */
-static void _POSIX_Spinlock_Manager_initialization(void)
-{
-  _Objects_Initialize_information(
-    &_POSIX_Spinlock_Information,    /* object information table */
-    OBJECTS_POSIX_API,               /* object API */
-    OBJECTS_POSIX_SPINLOCKS,         /* object class */
-    Configuration_POSIX_API.maximum_spinlocks,
-                                     /* maximum objects of this class */
-    sizeof( POSIX_Spinlock_Control ),/* size of this object's control block */
-    true,                            /* true if the name is a string */
-    _POSIX_PATH_MAX,                 /* maximum length of each object's name */
-    NULL                             /* Proxy extraction support callout */
-  );
-}
-
-RTEMS_SYSINIT_ITEM(
-  _POSIX_Spinlock_Manager_initialization,
-  RTEMS_SYSINIT_POSIX_SPINLOCK,
-  RTEMS_SYSINIT_ORDER_MIDDLE
-);
diff --git a/cpukit/posix/src/pspindestroy.c b/cpukit/posix/src/pspindestroy.c
index 42a6e76806..f5de88f04b 100644
--- a/cpukit/posix/src/pspindestroy.c
+++ b/cpukit/posix/src/pspindestroy.c
@@ -9,6 +9,8 @@
  *  COPYRIGHT (c) 1989-2007.
  *  On-Line Applications Research Corporation (OAR).
  *
+ *  Copyright (c) 2016 embedded brains GmbH
+ *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
  *  http://www.rtems.org/license/LICENSE.
@@ -20,33 +22,13 @@
 
 #include <rtems/posix/spinlockimpl.h>
 
-#include <errno.h>
-
 int pthread_spin_destroy( pthread_spinlock_t *spinlock )
 {
+#if defined(RTEMS_SMP) && defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
   POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-
-  _Objects_Allocator_lock();
-
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    _Objects_Allocator_unlock();
-    return EINVAL;
-  }
 
-  _CORE_spinlock_Acquire_critical( &the_spinlock->Spinlock, &lock_context );
-
-  if ( _CORE_spinlock_Is_busy( &the_spinlock->Spinlock ) ) {
-    _CORE_spinlock_Release( &the_spinlock->Spinlock, &lock_context );
-    _Objects_Allocator_unlock();
-    return EBUSY;
-  }
-
-  _CORE_spinlock_Release( &the_spinlock->Spinlock, &lock_context );
-
-  _Objects_Close( &_POSIX_Spinlock_Information, &the_spinlock->Object );
-  _POSIX_Spinlock_Free( the_spinlock );
-  _Objects_Allocator_unlock();
+  the_spinlock = _POSIX_Spinlock_Get( spinlock );
+  _SMP_ticket_lock_Destroy( &the_spinlock->Lock );
+#endif
   return 0;
 }
diff --git a/cpukit/posix/src/pspininit.c b/cpukit/posix/src/pspininit.c
index bc131e2e81..313633a11e 100644
--- a/cpukit/posix/src/pspininit.c
+++ b/cpukit/posix/src/pspininit.c
@@ -11,6 +11,8 @@
  *  COPYRIGHT (c) 1989-2006.
  *  On-Line Applications Research Corporation (OAR).
  *
+ *  Copyright (c) 2016 embedded brains GmbH
+ *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
  *  http://www.rtems.org/license/LICENSE.
@@ -20,58 +22,18 @@
 #include "config.h"
 #endif
 
-#include <pthread.h>
-#include <errno.h>
-
-#include <rtems/system.h>
 #include <rtems/posix/spinlockimpl.h>
 
-/*
- *  pthread_spinlock_init
- *
- *  This directive creates a spinlock.  A spinlock id is returned.
- *
- *  Input parameters:
- *    spinlock         - pointer to spinlock id
- *    pshared          - is this spinlock shared between processes
- *
- *  Output parameters:
- *    spinlock     - spinlock id
- *    0           - if successful
- *    error code  - if unsuccessful
- */
-
 int pthread_spin_init(
   pthread_spinlock_t  *spinlock,
   int                  pshared
 )
 {
-  POSIX_Spinlock_Control   *the_spinlock;
+#if defined(RTEMS_SMP) && defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+  POSIX_Spinlock_Control *the_spinlock;
 
-  if ( !spinlock )
-    return EINVAL;
-
-  switch ( pshared ) {
-    case PTHREAD_PROCESS_PRIVATE:    /* only supported values */
-      break;
-    case PTHREAD_PROCESS_SHARED:
-    default:
-      return EINVAL;
-  }
-
-  the_spinlock = _POSIX_Spinlock_Allocate();
-
-  if ( !the_spinlock ) {
-    _Objects_Allocator_unlock();
-    return EAGAIN;
-  }
-
-  _CORE_spinlock_Initialize( &the_spinlock->Spinlock );
-
-  _Objects_Open_u32( &_POSIX_Spinlock_Information, &the_spinlock->Object, 0 );
-
-  *spinlock = the_spinlock->Object.id;
-
-  _Objects_Allocator_unlock();
+  the_spinlock = _POSIX_Spinlock_Get( spinlock );
+  _SMP_ticket_lock_Initialize( &the_spinlock->Lock );
+#endif
   return 0;
 }
diff --git a/cpukit/posix/src/pspinlock.c b/cpukit/posix/src/pspinlock.c
index a2db911698..a9b04d8392 100644
--- a/cpukit/posix/src/pspinlock.c
+++ b/cpukit/posix/src/pspinlock.c
@@ -9,6 +9,8 @@
  *  COPYRIGHT (c) 1989-2007.
  *  On-Line Applications Research Corporation (OAR).
  *
+ *  Copyright (c) 2016 embedded brains GmbH
+ *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
  *  http://www.rtems.org/license/LICENSE.
@@ -19,24 +21,92 @@
 #endif
 
 #include <rtems/posix/spinlockimpl.h>
-#include <rtems/posix/posixapi.h>
+
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+RTEMS_STATIC_ASSERT(
+#if defined(RTEMS_SMP)
+  offsetof( POSIX_Spinlock_Control, Lock.next_ticket )
+#else
+  offsetof( POSIX_Spinlock_Control, reserved[ 0 ] )
+#endif
+    == offsetof( pthread_spinlock_t, _Lock._next_ticket ),
+  POSIX_SPINLOCK_T_LOCK_NEXT_TICKET
+);
+
+RTEMS_STATIC_ASSERT(
+#if defined(RTEMS_SMP)
+  offsetof( POSIX_Spinlock_Control, Lock.now_serving )
+#else
+  offsetof( POSIX_Spinlock_Control, reserved[ 1 ] )
+#endif
+    == offsetof( pthread_spinlock_t, _Lock._now_serving ),
+  POSIX_SPINLOCK_T_LOCK_NOW_SERVING
+);
+
+RTEMS_STATIC_ASSERT(
+  offsetof( POSIX_Spinlock_Control, interrupt_state )
+    == offsetof( pthread_spinlock_t, _interrupt_state ),
+  POSIX_SPINLOCK_T_INTERRUPT_STATE
+);
+
+RTEMS_STATIC_ASSERT(
+  sizeof( POSIX_Spinlock_Control ) == sizeof( pthread_spinlock_t ),
+  POSIX_SPINLOCK_T_SIZE
+);
+#else
+#if defined(RTEMS_SMP)
+POSIX_Spinlock_Control _POSIX_Spinlock_Global;
+
+uint32_t _POSIX_Spinlock_Owner = 0xffffffff;
+#endif
+
+int _POSIX_Spinlock_Nest_level;
+#endif
 
 int pthread_spin_lock( pthread_spinlock_t *spinlock )
 {
   POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-  Status_Control          status;
+  ISR_Level               level;
+#if defined(RTEMS_SMP) && defined(RTEMS_PROFILING)
+  Per_CPU_Control        *cpu_self;
+#endif
 
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    return EINVAL;
+  the_spinlock = _POSIX_Spinlock_Get( spinlock );
+  _ISR_Local_disable( level );
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+#if defined(RTEMS_SMP)
+#if defined(RTEMS_PROFILING)
+  /* The lock statistics are incorrect in case of nested pthread spinlocks */
+  cpu_self = _Per_CPU_Get();
+#endif
+  _SMP_ticket_lock_Acquire(
+    &the_spinlock->Lock,
+    &cpu_self->Lock_stats,
+    &cpu_self->Lock_stats_context
+  );
+#endif
+  the_spinlock->interrupt_state = level;
+#else
+#if defined(RTEMS_SMP)
+  if ( _POSIX_Spinlock_Owner != _SMP_Get_current_processor() ) {
+#if defined(RTEMS_PROFILING)
+    cpu_self = _Per_CPU_Get();
+#endif
+    _SMP_ticket_lock_Acquire(
+      &the_spinlock->Lock,
+      &cpu_self->Lock_stats,
+      &cpu_self->Lock_stats_context
+    );
+    _POSIX_Spinlock_Owner = _SMP_Get_current_processor();
+#endif
   }
 
-  status = _CORE_spinlock_Seize(
-    &the_spinlock->Spinlock,
-    true,
-    0,
-    &lock_context
-  );
-  return _POSIX_Get_error( status );
+  if ( ++_POSIX_Spinlock_Nest_level == 1) {
+    the_spinlock->interrupt_state = level;
+  }
+#endif
+  return 0;
 }
+
+int pthread_spin_trylock( pthread_spinlock_t *spinlock )
+  RTEMS_ALIAS( pthread_spin_lock );
diff --git a/cpukit/posix/src/pspintrylock.c b/cpukit/posix/src/pspintrylock.c
deleted file mode 100644
index a8264aba97..0000000000
--- a/cpukit/posix/src/pspintrylock.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/**
- * @file
- *
- * @brief Wait at a Spinlock
- * @ingroup POSIXAPI
- */
-
-/*
- *  COPYRIGHT (c) 1989-2007.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include <rtems/posix/spinlockimpl.h>
-#include <rtems/posix/posixapi.h>
-
-int pthread_spin_trylock( pthread_spinlock_t *spinlock )
-{
-  POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-  Status_Control          status;
-
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    return EINVAL;
-  }
-
-  status = _CORE_spinlock_Seize(
-    &the_spinlock->Spinlock,
-    false,
-    0,
-    &lock_context
-  );
-  return _POSIX_Get_error( status );
-}
diff --git a/cpukit/posix/src/pspinunlock.c b/cpukit/posix/src/pspinunlock.c
index b92473d7c1..b508df7384 100644
--- a/cpukit/posix/src/pspinunlock.c
+++ b/cpukit/posix/src/pspinunlock.c
@@ -11,6 +11,8 @@
  *  COPYRIGHT (c) 1989-2007.
  *  On-Line Applications Research Corporation (OAR).
  *
+ *  Copyright (c) 2016 embedded brains GmbH
+ *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
  *  http://www.rtems.org/license/LICENSE.
@@ -21,19 +23,33 @@
 #endif
 
 #include <rtems/posix/spinlockimpl.h>
-#include <rtems/posix/posixapi.h>
 
-int pthread_spin_unlock( pthread_spinlock_t *spinlock )
+int pthread_spin_unlock( pthread_spinlock_t *lock )
 {
   POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-  Status_Control          status;
+  ISR_Level               level;
 
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    return EINVAL;
+  the_spinlock = _POSIX_Spinlock_Get( lock );
+  level = the_spinlock->interrupt_state;
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+#if defined(RTEMS_SMP)
+  _SMP_ticket_lock_Release(
+    &the_spinlock->Lock,
+    &_Per_CPU_Get()->Lock_stats_context
+  );
+#endif
+  _ISR_Local_enable( level );
+#else
+  if ( --_POSIX_Spinlock_Nest_level == 0 ) {
+#if defined(RTEMS_SMP)
+    _POSIX_Spinlock_Owner = 0xffffffff;
+    _SMP_ticket_lock_Release(
+      &the_spinlock->Lock,
+      &_Per_CPU_Get()->Lock_stats_context
+    );
+#endif
+    _ISR_Local_enable( level );
   }
-
-  status = _CORE_spinlock_Surrender( &the_spinlock->Spinlock, &lock_context );
-  return _POSIX_Get_error( status );
+#endif
+  return 0;
 }