From 702c5f5b42e975c35a94f1ae3d39a77815f36f70 Mon Sep 17 00:00:00 2001
From: Joel Sherrill <joel.sherrill@OARcorp.com>
Date: Wed, 27 Oct 1999 15:29:18 +0000
Subject: The rxgen960 BSP and i960 RPM support was submitted by Mark Bronson
 <mark@ramix.com> of RAMIX.

---
 c/src/lib/libbsp/i960/rxgen960/shmsupp/lock.c | 76 +++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 c/src/lib/libbsp/i960/rxgen960/shmsupp/lock.c

(limited to 'c/src/lib/libbsp/i960/rxgen960/shmsupp/lock.c')

diff --git a/c/src/lib/libbsp/i960/rxgen960/shmsupp/lock.c b/c/src/lib/libbsp/i960/rxgen960/shmsupp/lock.c
new file mode 100644
index 0000000000..f74188a1b3
--- /dev/null
+++ b/c/src/lib/libbsp/i960/rxgen960/shmsupp/lock.c
@@ -0,0 +1,76 @@
+/*  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) 1989-1997.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may in
+ *  the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+#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, oldlock;
+
+  rtems_interrupt_disable( isr_level );
+    Shm_isrstat = isr_level;
+    while ( 1 ) {
+      atomic_modify( SHM_LOCK_VALUE, &lq_cb->lock, oldlock );
+      if ( !(oldlock & SHM_LOCK_VALUE) )
+        return;
+      delay( 28 );        /* delay 28 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 );
+}
+
-- 
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