1 files changed, 101 insertions, 0 deletions
diff --git a/cpukit/score/cpu/arm/rtems/score/cpusmplock.h b/cpukit/score/cpu/arm/rtems/score/cpusmplock.h
new file mode 100644
index 0000000000..46592f432b
--- /dev/null
+++ b/cpukit/score/cpu/arm/rtems/score/cpusmplock.h
@@ -0,0 +1,101 @@
+/**
+ * @file
+ *
+ * @ingroup ScoreSMPLockARM
+ *
+ * @brief ARM SMP Lock Implementation
+ */
+
+/*
+ * 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_ARM_SMPLOCK_H
+#define _RTEMS_SCORE_ARM_SMPLOCK_H
+
+#include <rtems/score/cpu.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @defgroup ScoreSMPLockARM ARM SMP Locks
+ *
+ * @ingroup ScoreSMPLock
+ *
+ * A ticket lock implementation is used.
+ *
+ * @{
+ */
+
+typedef struct {
+  uint32_t next_ticket;
+  uint32_t now_serving;
+} CPU_SMP_lock_Control;
+
+#define CPU_SMP_LOCK_INITIALIZER { 0, 0 }
+
+static inline void _CPU_SMP_lock_Initialize( CPU_SMP_lock_Control *lock )
+{
+  lock->next_ticket = 0;
+  lock->now_serving = 0;
+}
+
+static inline void _CPU_SMP_lock_Acquire( CPU_SMP_lock_Control *lock )
+{
+  uint32_t my_ticket;
+  uint32_t next_ticket;
+  uint32_t status;
+
+  __asm__ volatile (
+    "1: ldrex %[my_ticket], [%[next_ticket_addr]]\n"
+    "add %[next_ticket], %[my_ticket], #1\n"
+    "strex %[status], %[next_ticket], [%[next_ticket_addr]]\n"
+    "teq %[status], #0\n"
+    "bne 1b"
+    : [my_ticket] "=&r" (my_ticket),
+      [next_ticket] "=&r" (next_ticket),
+      [status] "=&r" (status)
+    : [next_ticket_addr] "r" (&lock->next_ticket)
+    : "cc", "memory"
+  );
+
+  while ( my_ticket != lock->now_serving ) {
+    _ARM_Wait_for_event();
+  }
+
+  _ARM_Data_memory_barrier();
+}
+
+static inline void _CPU_SMP_lock_Release( CPU_SMP_lock_Control *lock )
+{
+  _ARM_Data_memory_barrier();
+  ++lock->now_serving;
+  _ARM_Data_synchronization_barrier();
+  _ARM_Send_event();
+}
+
+#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_ARM_SMPLOCK_H */