xnu-1699.22.73.tar.gz

[apple/xnu.git] / iokit / Kernel / x86_64 / IOSharedLock.s

diff --git a/iokit/Kernel/x86_64/IOSharedLock.s b/iokit/Kernel/x86_64/IOSharedLock.s
index 69183e016ab4cace47a1714829627b271c6d00ee..d5e5ecabc44e70a906f94e05dd79f4f87ddc287f 100644 (file)
--- a/iokit/Kernel/x86_64/IOSharedLock.s
+++ b/iokit/Kernel/x86_64/IOSharedLock.s
@@ -1,19 +1,14 @@
 /*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1998-2010 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_OSREFERENCE_LICENSE_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 file.
+ * 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
@@ -23,7 +18,43 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ * @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            $0, (%rdi)
+END(_OSSpinLockUnlock)
+
+
+/*
+ * int
+ * OSSpinLockTry(p)
+ *     int *p;
+ *
+ * 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)
+       xorl            %eax, %eax
+       orl             $-1, %edx
+       lock
+       cmpxchgl        %edx, (%rdi)
+       setz            %dl
+       movzbl          %dl, %eax
+END(_OSSpinLockTry)