X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/e3027f41d0120b4278cca462f397b6619dcd9ac5..55e303ae13a4cf49d70f2294092726f2fffb9ef2:/iokit/IOKit/ppc/IOSharedLockImp.h

diff --git a/iokit/IOKit/ppc/IOSharedLockImp.h b/iokit/IOKit/ppc/IOSharedLockImp.h
index 030fd4913..c6c062fd5 100644
--- a/iokit/IOKit/ppc/IOSharedLockImp.h
+++ b/iokit/IOKit/ppc/IOSharedLockImp.h
@@ -3,19 +3,22 @@
  *
  * @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@
  */
@@ -93,20 +96,48 @@
 
 #ifndef KERNEL
 LEAF(_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(_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...
+END(_IOSpinLock)
 #endif
 
 /*
@@ -118,7 +149,6 @@ END(_ev_lock)
  */
 
 LEAF(_ev_unlock)
-LEAF(_IOSpinUnlock)
 	sync
 	li	a7,0
 	stw	a7,0(a0)
@@ -126,6 +156,14 @@ LEAF(_IOSpinUnlock)
 	blr
 END(_ev_unlock)
 
+LEAF(_IOSpinUnlock)
+	sync
+	li	a7,0
+	stw	a7,0(a0)
+	ENABLE_PREEMPTION()
+	blr
+END(_IOSpinUnlock)
+
 
 /*
  *	ev_try_lock(p)
@@ -135,25 +173,61 @@ END(_ev_unlock)
  */
 
 LEAF(_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(_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
+		
+END(_IOTrySpinLock)
+
 #endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */