1 files changed, 90 insertions, 0 deletions
diff --git a/bsps/sparc/leon3/mpci/lock.c b/bsps/sparc/leon3/mpci/lock.c
new file mode 100644
index 0000000000..5b118f24b6
--- /dev/null
+++ b/bsps/sparc/leon3/mpci/lock.c
@@ -0,0 +1,90 @@
+/**
+ *  @file
+ *
+ *  LEON3 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) 1989-2012.
+ *  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.
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+#include <shm_driver.h>
+
+
+/*
+ *  Initialize the lock for the specified locked queue.
+ */
+void Shm_Initialize_lock(
+  Shm_Locked_queue_Control *lq_cb
+)
+{
+  lq_cb->lock = LQ_UNLOCKED;
+}
+
+/*
+ *  This shared memory locked queue support routine locks the
+ *  specified locked queue.  It disables interrupts to prevent
+ *  a deadlock condition.
+ */
+extern unsigned int LEON3_Atomic_Swap(uint32_t value, uint32_t *address);
+
+__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
+)
+{
+  uint32_t isr_level;
+  uint32_t *lockptr = (uint32_t *) &lq_cb->lock;
+  uint32_t 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);
+      /*
+       *  If not available, then may want to delay to reduce load on lock.
+       */
+   }
+}
+
+/*
+ *  Shm_Unlock
+ *
+ *  Unlock the lock for the specified locked queue.
+ */
+
+void Shm_Unlock(
+  Shm_Locked_queue_Control *lq_cb
+)
+{
+  uint32_t isr_level;
+
+  lq_cb->lock = SHM_UNLOCK_VALUE;
+  isr_level = Shm_isrstat;
+  rtems_interrupt_enable( isr_level );
+}
+