xnu-792.tar.gz

[apple/xnu.git] / libkern / ppc / OSAtomic.s

diff --git a/libkern/ppc/OSAtomic.s b/libkern/ppc/OSAtomic.s
index 39481085db98673826604017716b0d9e5a14a64d..f1834d9980a51a5d2d1b3562774b3f2049348174 100644 (file)
--- a/libkern/ppc/OSAtomic.s
+++ b/libkern/ppc/OSAtomic.s
@@ -41,67 +41,57 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 .macro ENTRY
-       .text
-       .align          2
-       .globl          $0
+    .text
+    .align     2
+    .globl     $0
 $0:
 .endmacro
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 /*
-int OSCompareAndSwap( UInt32 oldVal, UInt32 newVal, UInt32 * addr )
+int     OSCompareAndSwap( UInt32 oldVal, UInt32 newVal, UInt32 * addr )
+    This is now an alias to hw_compare_and_store, see xnu/libkern/Makefile.
+
+void * OSDequeueAtomic(void ** inList, SInt32 inOffset)
+    This is also aliased, to hw_dequeue_atomic.
+    
+void   OSEnqueueAtomic(void ** inList, void * inNewLink, SInt32 inOffset)
+    This is aliased to hw_queue_atomic.
 */
 
-
-       ENTRY   _OSCompareAndSwap
-
-       lwarx   r6,     0,r5            /* CEMV10 */
-.L_CASretry:
-       lwarx   r6,     0,r5
-       cmpw    r6,     r3
-       bne-    .L_CASfail
-       stwcx.  r4,     0,r5
-       bne-    .L_CASretry
-       isync
-       li      r3,     1
-       blr
-.L_CASfail:
-       li      r3,     0
-       blr
-
-
+/*
+Note:  We can not use the hw_atomic routines provided by osfmk/ppc as
+the return the result of the addition not the original value.
+*/
 /*
 SInt32 OSDecrementAtomic(SInt32 * value)
 */
-       ENTRY   _OSDecrementAtomic
-       mr      r4, r3
-       li      r3, -1
-       b       _OSAddAtomic
+    ENTRY      _OSDecrementAtomic
+    mr         r4, r3
+    li         r3, -1
+    b          _OSAddAtomic
 
 /*
 SInt32 OSIncrementAtomic(SInt32 * value)
 */
 
-       ENTRY   _OSIncrementAtomic
-       mr      r4, r3
-       li      r3, 1
+    .align     5
+
+    ENTRY      _OSIncrementAtomic
+    mr         r4, r3
+    li         r3, 1
 
 /*
 SInt32 OSAddAtomic(SInt32 amount, SInt32 * value)
 */
 
-       ENTRY   _OSAddAtomic
-
-       mr      r5,r3                           /* Save the increment */
-       lwarx   r3,0,r4                         /* CEMV10 */
+    ENTRY      _OSAddAtomic
 
+    mr         r5,r3           /* Save the increment */
 .L_AAretry:
-       lwarx   r3, 0, r4                       /* Grab the area value */
-       add     r6, r3, r5                      /* Add the value */
-       stwcx.  r6, 0, r4                       /* Try to save the new value */
-       bne-    .L_AAretry                      /* Didn't get it, try again... */
-       blr                                     /* Return the original value */
-
-
-
+    lwarx      r3, 0, r4       /* Grab the area value */
+    add                r6, r3, r5      /* Add the value */
+    stwcx.     r6, 0, r4       /* Try to save the new value */
+    bne-       .L_AAretry      /* Didn't get it, try again... */
+    blr                                /* Return the original value */