xnu-517.tar.gz

[apple/xnu.git] / iokit / IOKit / i386 / IOSharedLockImp.h

diff --git a/iokit/IOKit/i386/IOSharedLockImp.h b/iokit/IOKit/i386/IOSharedLockImp.h
index 0478bc429482438269765c2adbefd267389c91a1..20be6ebf5d1ff1c6f7d0f06a1cc118ce35fc806b 100644 (file)
--- a/iokit/IOKit/i386/IOSharedLockImp.h
+++ b/iokit/IOKit/i386/IOSharedLockImp.h
@@ -75,16 +75,15 @@
 #ifndef KERNEL
 LEAF(_ev_lock, 0)
 LEAF(_IOSpinLock, 0)
-       push    %eax
-       push    %ecx
-       movl    $1, %ecx
-       movl    12(%esp), %eax  
-_spin:
-       xchgl   %ecx,0(%eax)
-       cmp     $0, %ecx
-       jne     _spin
-       pop     %ecx
-       pop     %eax
+       movl            4(%esp), %ecx
+0:
+       xorl            %eax, %eax
+       rep
+       nop             /* pause for hyperthreaded CPU's */
+       lock
+       cmpxchgl        %ecx, (%ecx)
+       jne             0b
+       ret
 END(_ev_lock)
 #endif
 
@@ -97,11 +96,10 @@ END(_ev_lock)
  */
 LEAF(_ev_unlock, 0)
 LEAF(_IOSpinUnlock, 0)
-       push    %eax
-       movl    8(%esp),%eax
-       movl    $0,0(%eax)
+       movl            4(%esp), %ecx
+       movl            $0, (%ecx)
        ENABLE_PREEMPTION()
-       pop     %eax
+       ret
 END(_ev_unlock)
 
 
@@ -117,9 +115,11 @@ END(_ev_unlock)
 LEAF(_ev_try_lock, 0)
 LEAF(_IOTrySpinLock, 0)
         DISABLE_PREEMPTION()
-       movl    4(%esp), %eax
-   lock;bts    $0, 0(%eax)
-       jb      1f
+        movl            4(%esp), %ecx 
+       xorl            %eax, %eax
+        lock
+        cmpxchgl        %ecx, (%ecx)
+       jne     1f
        movl    $1, %eax                /* yes */
        ret
 1: