1 files changed, 100 insertions, 0 deletions
diff --git a/cpukit/score/cpu/i386/rtems/score/cpusmplock.h b/cpukit/score/cpu/i386/rtems/score/cpusmplock.h
new file mode 100644
index 0000000000..6fadfef419
--- /dev/null
+++ b/cpukit/score/cpu/i386/rtems/score/cpusmplock.h
@@ -0,0 +1,100 @@
+/**
+ * @file
+ *
+ * @ingroup ScoreSMPLockI386
+ *
+ * @brief i386 SMP Lock Implementation
+ */
+
+/*
+ * COPYRIGHT (c) 1989-2011.
+ * On-Line Applications Research Corporation (OAR).
+ *
+ * Copyright (c) 2013 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.com/license/LICENSE.
+ */
+
+#ifndef _RTEMS_SCORE_I386_SMPLOCK_H
+#define _RTEMS_SCORE_I386_SMPLOCK_H
+
+#include <rtems/score/cpu.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @defgroup ScoreSMPLockI386 i386 SMP Locks
+ *
+ * @ingroup ScoreSMPLock
+ *
+ * The implementation is Test and Swap.
+ *
+ * @{
+ */
+
+typedef struct {
+  uint32_t locked;
+} CPU_SMP_lock_Control;
+
+#define CPU_SMP_LOCK_INITIALIZER { 0 }
+
+static inline void _CPU_SMP_lock_Initialize( CPU_SMP_lock_Control *lock )
+{
+  lock->locked = 0;
+}
+
+static inline uint32_t _I386_Atomic_swap(
+  volatile uint32_t *address,
+  uint32_t value
+)
+{
+  uint32_t previous;
+
+  asm volatile(
+    "lock; xchgl %0, %1"
+    : "+m" (*address), "=a" (previous)
+    : "1" (value)
+    : "cc"
+  );
+
+  return previous;
+}
+
+static inline void _CPU_SMP_lock_Acquire( CPU_SMP_lock_Control *lock )
+{
+  do {
+    while ( lock->locked ) {
+      /* Do nothing */
+    }
+  } while ( _I386_Atomic_swap( &lock->locked, 1 ) );
+}
+
+static inline void _CPU_SMP_lock_Release( CPU_SMP_lock_Control *lock )
+{
+  RTEMS_COMPILER_MEMORY_BARRIER();
+  lock->locked = 0;
+}
+
+#define _CPU_SMP_lock_ISR_disable_and_acquire( lock, isr_cookie ) \
+  do { \
+    _CPU_ISR_Disable( isr_cookie ); \
+    _CPU_SMP_lock_Acquire( lock ); \
+  } while (0)
+
+#define _CPU_SMP_lock_Release_and_ISR_enable( lock, isr_cookie ) \
+  do { \
+    _CPU_SMP_lock_Release( lock ); \
+    _CPU_ISR_Enable( isr_cookie ); \
+  } while (0)
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* _RTEMS_SCORE_I386_SMPLOCK_H */