]> git.saurik.com Git - apple/xnu.git/blobdiff - iokit/IOKit/ppc/IOSharedLockImp.h
xnu-344.23.tar.gz
[apple/xnu.git] / iokit / IOKit / ppc / IOSharedLockImp.h
index c6c062fd57f58ac1db51ad3d438abab8a48ec33b..01bb64e76219fb2c7d35cd43a0d4c53d9145c2ad 100644 (file)
@@ -3,22 +3,19 @@
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * 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.
- * 
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * This 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,
  * 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.
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
 
 #ifndef KERNEL
 LEAF(_ev_lock)
 
 #ifndef KERNEL
 LEAF(_ev_lock)
-
-               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...
-               
-               
+       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
 END(_ev_lock)
 
 LEAF(_IOSpinLock)
 END(_ev_lock)
 
 LEAF(_IOSpinLock)
-
-               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...
+       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
 END(_IOSpinLock)
 #endif
 
 END(_IOSpinLock)
 #endif
 
@@ -173,61 +156,45 @@ END(_IOSpinUnlock)
  */
 
 LEAF(_ev_try_lock)
  */
 
 LEAF(_ev_try_lock)
-       
-               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
-               
+       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
 END(_ev_try_lock)
 
 LEAF(_IOTrySpinLock)
 END(_ev_try_lock)
 
 LEAF(_IOTrySpinLock)
-       
-               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
-               
+       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
 END(_IOTrySpinLock)
 
 #endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */
 END(_IOTrySpinLock)
 
 #endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */