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 83cc4894686ff907e1dc178fddbe0c10f8407ea7..9360dce09401bdddad298f8f6a810623ad9fd258 100644 (file)
--- a/iokit/Kernel/i386/IOSharedLock.s
+++ b/iokit/Kernel/i386/IOSharedLock.s
@@ -1,31 +1,64 @@
 /*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1998-2010 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
+ * @APPLE_LICENSE_HEADER_START@
  * 
- * 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.  The rights granted to you under the 
- * License may not be used to create, or enable the creation or 
- * redistribution of, unlawful or unlicensed copies of an Apple operating 
- * system, or to circumvent, violate, or enable the circumvention or 
- * violation of, any terms of an Apple operating system software license 
- * agreement.
- *
- * Please obtain a copy of the License at 
- * http://www.opensource.apple.com/apsl/ and read it before using this 
+ * 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.
- *
- * 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, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
- * Please see the License for the specific language governing rights and 
+ * 
+ * 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, 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 <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;
  *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
+ * Try to lock p.  Return zero if not successful.
  */
-#include <IOKit/machine/IOSharedLockImp.h>
 
+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)