xnu-517.tar.gz

[apple/xnu.git] / iokit / IOKit / ppc / IOSharedLockImp.h

diff --git a/iokit/IOKit/ppc/IOSharedLockImp.h b/iokit/IOKit/ppc/IOSharedLockImp.h
index 01bb64e76219fb2c7d35cd43a0d4c53d9145c2ad..c6c062fd57f58ac1db51ad3d438abab8a48ec33b 100644 (file)
--- a/iokit/IOKit/ppc/IOSharedLockImp.h
+++ b/iokit/IOKit/ppc/IOSharedLockImp.h
@@ -3,19 +3,22 @@
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
  *
  * @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,
  * 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@
  */
  * 
  * @APPLE_LICENSE_HEADER_END@
  */


@@ -93,33 +96,47 @@
 
 #ifndef KERNEL
 LEAF(_ev_lock)
 
 #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)
 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
 
 END(_IOSpinLock)
 #endif
 


@@ -156,45 +173,61 @@ END(_IOSpinUnlock)
  */
 
 LEAF(_ev_try_lock)
  */
 
 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)
 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 */
 END(_IOTrySpinLock)
 
 #endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */