*
* @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.
+ * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
*
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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 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@
*/
#ifndef KERNEL
LEAF(_ev_lock)
- li a6,1 // lock value
- lwarx a7,0,a0 // CEMV10
-9:
- sync
- lwarx a7,0,a0 // read the lock
- cmpwi cr0,a7,0 // is it busy?
- bne- 9b // yes, spin
- sync
- stwcx. a6,0,a0 // try to get the lock
- bne- 9b // failed, try again
- isync
- blr // got it, return
+
+ li a6,1 // lock value
+
+8: lwz a7,0(a0) // Get lock word
+ mr. a7,a7 // Is it held?
+ bne-- 8b // Yup...
+
+9: lwarx a7,0,a0 // read the lock
+ mr. a7,a7 // Is it held?
+ bne-- 7f // yes, kill reservation
+ stwcx. a6,0,a0 // try to get the lock
+ bne-- 9b // failed, try again
+ isync
+ blr // got it, return
+
+7: li a7,-4 // Point to a spot in the red zone
+ stwcx. a7,a7,r1 // Kill reservation
+ b 8b // Go wait some more...
+
+
END(_ev_lock)
LEAF(_IOSpinLock)
- li a6,1 // lock value
- lwarx a7,0,a0 // CEMV10
-9:
- sync
- lwarx a7,0,a0 // read the lock
- cmpwi cr0,a7,0 // is it busy?
- bne- 9b // yes, spin
- sync
- stwcx. a6,0,a0 // try to get the lock
- bne- 9b // failed, try again
- isync
- blr // got it, return
+
+ li a6,1 // lock value
+
+8: lwz a7,0(a0) // Get lock word
+ mr. a7,a7 // Is it held?
+ bne-- 8b // Yup...
+
+9: lwarx a7,0,a0 // read the lock
+ mr. a7,a7 // Is it held?
+ bne-- 7f // yes, kill reservation
+ stwcx. a6,0,a0 // try to get the lock
+ bne-- 9b // failed, try again
+ isync
+ blr // got it, return
+
+7: li a7,-4 // Point to a spot in the red zone
+ stwcx. a7,a7,r1 // Kill reservation
+ b 8b // Go wait some more...
END(_IOSpinLock)
#endif
*/
LEAF(_ev_try_lock)
- li a6,1 // lock value
- DISABLE_PREEMPTION()
- lwarx a7,0,a0 // CEMV10
-8:
- sync
- lwarx a7,0,a0 // read the lock
- cmpwi cr0,a7,0 // is it busy?
- bne- 9f // yes, give up
- sync
- stwcx. a6,0,a0 // try to get the lock
- bne- 8b // failed, try again
- li a0,1 // return TRUE
- isync
- blr
-9:
- ENABLE_PREEMPTION()
- li a0,0 // return FALSE
- blr
+
+ DISABLE_PREEMPTION()
+
+ li a6,1 // lock value
+
+ lwz a7,0(a0) // Get lock word
+ mr. a7,a7 // Is it held?
+ bne-- 6f // Yup...
+
+9: lwarx a7,0,a0 // read the lock
+ mr. a7,a7 // Is it held?
+ bne-- 7f // yes, kill reservation
+ stwcx. a6,0,a0 // try to get the lock
+ bne-- 9b // failed, try again
+ li a0,1 // return TRUE
+ isync
+ blr // got it, return
+
+7: li a7,-4 // Point to a spot in the red zone
+ stwcx. a7,a7,r1 // Kill reservation
+
+6:
+ ENABLE_PREEMPTION()
+ li a0,0 // return FALSE
+ blr
+
END(_ev_try_lock)
LEAF(_IOTrySpinLock)
- li a6,1 // lock value
- DISABLE_PREEMPTION()
- lwarx a7,0,a0 // CEMV10
-8:
- sync
- lwarx a7,0,a0 // read the lock
- cmpwi cr0,a7,0 // is it busy?
- bne- 9f // yes, give up
- sync
- stwcx. a6,0,a0 // try to get the lock
- bne- 8b // failed, try again
- li a0,1 // return TRUE
- isync
- blr
-9:
- ENABLE_PREEMPTION()
- li a0,0 // return FALSE
- blr
+
+ DISABLE_PREEMPTION()
+
+ li a6,1 // lock value
+
+ lwz a7,0(a0) // Get lock word
+ mr. a7,a7 // Is it held?
+ bne-- 6f // Yup...
+
+9: lwarx a7,0,a0 // read the lock
+ mr. a7,a7 // Is it held?
+ bne-- 7f // yes, kill reservation
+ stwcx. a6,0,a0 // try to get the lock
+ bne-- 9b // failed, try again
+ li a0,1 // return TRUE
+ isync
+ blr // got it, return
+
+7: li a7,-4 // Point to a spot in the red zone
+ stwcx. a7,a7,r1 // Kill reservation
+
+6:
+ ENABLE_PREEMPTION()
+ li a0,0 // return FALSE
+ blr
+
END(_IOTrySpinLock)
#endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */
projects / apple / xnu.git / blobdiff