1 files changed, 97 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/sparc/leon3/shmsupp/lock.c b/c/src/lib/libbsp/sparc/leon3/shmsupp/lock.c
new file mode 100644
index 0000000000..a750f818ac
--- /dev/null
+++ b/c/src/lib/libbsp/sparc/leon3/shmsupp/lock.c
@@ -0,0 +1,97 @@
+/*  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) 1989-1999.
+ *  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.com/license/LICENSE.
+ *
+ *  lock.c,v 1.9.4.1 2003/09/04 18:44:56 joel Exp
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+#include <shm_driver.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.
+ */
+
+asm(
+    ".text\n"
+    ".align 4\n"
+"LEON3_Atomic_Swap:\n"
+"	retl\n"	
+"	swapa [%o1] 1, %o0\n"
+); 
+									
+
+
+void Shm_Lock(
+  Shm_Locked_queue_Control *lq_cb
+)
+{
+  rtems_unsigned32 isr_level;
+  rtems_unsigned32 *lockptr = (rtems_unsigned32 *) &lq_cb->lock;
+  rtems_unsigned32 lock_value;
+
+  lock_value = SHM_LOCK_VALUE;
+  rtems_interrupt_disable( isr_level );
+
+    Shm_isrstat = isr_level;
+    while ( lock_value ) {
+      lock_value = LEON3_Atomic_Swap(lock_value, lockptr);
+/*       asm volatile( "" */
+/*                          : "=r" (lockptr), "=r" (lock_value) */
+/*                          : "0" (lockptr),  "1" (lock_value) */
+/*                   ); */
+      /*
+       *  If not available, then may want to delay to reduce load on lock.
+       */
+
+/*       if ( lock_value ) */
+/*         rtems_bsp_delay( 10 );   /\* approximately 10 microseconds *\/ */
+   }
+}
+
+/*
+ *  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 );
+}
+