xnu-1699.22.81.tar.gz

[apple/xnu.git] / iokit / Kernel / i386 / IOSharedLock.s

diff --git a/iokit/Kernel/i386/IOSharedLock.s b/iokit/Kernel/i386/IOSharedLock.s
index de84a9173c7b6caf947c0f1e30f8ecdbacade6fc..9360dce09401bdddad298f8f6a810623ad9fd258 100644 (file)
--- a/iokit/Kernel/i386/IOSharedLock.s
+++ b/iokit/Kernel/i386/IOSharedLock.s
@@ -1,23 +1,64 @@
 /*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1998-2010 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
-#include <IOKit/machine/IOSharedLockImp.h>
 
+#include <architecture/i386/asm_help.h>
+
+       TEXT
+
+/*
+ * void
+ * OSSpinLockUnlock(p)
+ *     int *p;
+ *
+ * Unlock the lock pointed to by p.
+ */
+
+LEAF(_OSSpinLockUnlock, 0)
+LEAF(_IOSpinUnlock, 0)
+LEAF(_ev_unlock, 0)
+       movl            4(%esp), %ecx
+       movl            $0, (%ecx)
+END(_OSSpinLockUnlock)
+
+
+/*
+ * int
+ * OSSpinLockTry(p)
+ *     int *p;
+ *
+ * Try to lock p.  Return zero if not successful.
+ */
+
+LEAF(_OSSpinLockTry, 0)
+LEAF(_IOTrySpinLock, 0)
+LEAF(_ev_try_lock, 0)
+        movl            4(%esp), %ecx 
+       xorl            %eax, %eax
+        lock
+        cmpxchgl        %ecx, (%ecx)
+       jne     1f
+       movl    $1, %eax                /* yes */
+       ret
+1:
+       xorl    %eax, %eax              /* no */
+END(_OSSpinLockTry)