1 files changed, 75 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/mvme136/shmsupp/lock.c b/c/src/lib/libbsp/m68k/mvme136/shmsupp/lock.c
new file mode 100644
index 0000000000..5ccc406af5
--- /dev/null
+++ b/c/src/lib/libbsp/m68k/mvme136/shmsupp/lock.c
@@ -0,0 +1,75 @@
+/*  Shared Memory Lock Routines
+ *
+ *  This shared memory locked queue support routine need to be
+ *  able to lock the specified locked queue.  Interrupts are
+ *  disabled while the queue is locked to prevent preemption
+ *  and deadlock when two tasks poll for the same lock.
+ *  previous level.
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+#include <shm.h>
+
+/*
+ *  Shm_Initialize_lock
+ *
+ *  Initialize the lock for the specified locked queue.
+ */
+
+void Shm_Initialize_lock(
+  Shm_Locked_queue_Control *lq_cb
+)
+{
+  lq_cb->lock = LQ_UNLOCKED;
+}
+
+/*  void _Shm_Lock( &lq_cb )
+ *
+ *  This shared memory locked queue support routine locks the
+ *  specified locked queue.  It disables interrupts to prevent
+ *  a deadlock condition.
+ */
+
+void Shm_Lock(
+  Shm_Locked_queue_Control *lq_cb
+)
+{
+  rtems_unsigned32 isr_level;
+  rtems_unsigned32 *lockptr = (rtems_unsigned32 *)&lq_cb->lock;
+
+  rtems_interrupt_disable( isr_level );
+    Shm_isrstat = isr_level;
+    asm volatile( "lockit:"    : : );
+    asm volatile( "tas %0@"    : "=a" (lockptr) : "0" (lockptr) );
+    asm volatile( "bne lockit" : : );
+/* should delay */
+}
+
+/*
+ *  Shm_Unlock
+ *
+ *  Unlock the lock for the specified locked queue.
+ */
+
+void Shm_Unlock(
+  Shm_Locked_queue_Control *lq_cb
+)
+{
+  rtems_unsigned32 isr_level;
+
+  lq_cb->lock = SHM_UNLOCK_VALUE;
+  isr_level = Shm_isrstat;
+  rtems_interrupt_enable( isr_level );
+}
+