xnu-1228.tar.gz

[apple/xnu.git] / libkern / i386 / OSAtomic.s

diff --git a/libkern/i386/OSAtomic.s b/libkern/i386/OSAtomic.s
index 83ab5e3d0ed3cbc31fbfcb0c2519f28fa95eb29d..2be21d1a88ba08705d36af1499f4fa7459da80f2 100644 (file)
--- a/libkern/i386/OSAtomic.s
+++ b/libkern/i386/OSAtomic.s
@@ -1,16 +1,19 @@
 /*
  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * 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.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * 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
@@ -20,32 +23,82 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
-#;**************************************************************************
-#;* Boolean OSCompareAndSwap(SInt32 oldValue, SInt32 newValue, SInt32 * ptr) *
-#;**************************************************************************
+#;***************************************************************************
+#;* Boolean OSCompareAndSwap(SInt32 oldValue, SInt32 newValue, SInt32 *ptr) *
+#;***************************************************************************
 
        .globl _OSCompareAndSwap
 
 _OSCompareAndSwap:
-       #; this is _lame_, the project will not currently accept asm code that
-       #; requires anything beyond a 386, but that chip:
-       #; - does not support MP
-       #; - does not support the cmpxchgl instruction
-       #; - does not support the lock meta-instruction
-       #; so what is a poor guy to do?  comment it out...
+       movl             4(%esp), %eax  #; oldValue
+       movl             8(%esp), %edx  #; newValue
+       movl            12(%esp), %ecx  #; ptr
+       lock
+       cmpxchgl        %edx, 0(%ecx)   #; CAS (eax is an implicit operand)
+       sete            %al                     #; did CAS succeed? (TZ=1)
+       movzbl          %al, %eax               #; clear out the high bytes
+       ret
+
+#;*****************************************************************************
+#;* Boolean OSCompareAndSwap64(SInt64 oldValue, SInt64 newValue, SInt64 *ptr) *
+#;*****************************************************************************
+
+       .globl _OSCompareAndSwap64
+
+_OSCompareAndSwap64:
        pushl           %edi
-       pushl           %esi
-       movl            0+8+4(%esp),%eax        #; oldValue
-       movl            4+8+4(%esp),%edi        #; newValue
-       movl            8+8+4(%esp),%esi        #; ptr
+       pushl           %ebx
+
+       movl             4+8(%esp), %eax        #; low 32-bits of oldValue
+       movl             8+8(%esp), %edx        #; high 32-bits of oldValue
+       movl            12+8(%esp), %ebx        #; low 32-bits of newValue
+       movl            16+8(%esp), %ecx        #; high 32-bits of newValue
+       movl            20+8(%esp), %edi        #; ptr
        lock
-       cmpxchgl        %edi,0(%esi)            #; CAS (eax is an implicit operand)
-       sete            %al                                     #; did CAS succeed? (TZ=1)
-       andl            $0x000000ff,%eax        #; clear out the high bytes (has to be an easier way...)
-       popl            %esi
+       cmpxchg8b       0(%edi)         #; CAS (eax:edx, ebx:ecx implicit)
+       sete            %al                     #; did CAS succeed? (TZ=1)
+       movzbl          %al, %eax               #; clear out the high bytes
+
+       popl            %ebx
        popl            %edi
        ret
 
+#;*******************************************************
+#;* SInt64 OSAddAtomic64(SInt64 theAmount, SInt64 *ptr) *
+#;*******************************************************
+
+       .globl  _OSAddAtomic64
+_OSAddAtomic64:
+       pushl           %edi
+       pushl           %ebx
+
+       movl            12+8(%esp), %edi        #; ptr
+       movl            0(%edi), %eax           #; load low 32-bits of *ptr
+       movl            4(%edi), %edx           #; load high 32-bits of *ptr
+1:
+       movl            %eax, %ebx              
+       movl            %edx, %ecx              #; ebx:ecx := *ptr
+       addl            4+8(%esp), %ebx
+       adcl            8+8(%esp), %ecx         #; ebx:ecx := *ptr + theAmount
+       lock
+       cmpxchg8b       0(%edi)         #; CAS (eax:edx, ebx:ecx implicit)
+       jnz             1b              #; - failure: eax:edx re-loaded, retry
+                                       #; - success: old value in eax:edx
+       popl            %ebx
+       popl            %edi
+       ret
+
+#;*******************************************************
+#; SInt32 OSAddAtomic(SInt32 delta, SInt32 *address) 
+#;*******************************************************
+
+       .globl  _OSAddAtomic
+_OSAddAtomic:
+       movl    4(%esp), %eax           #; Load addend
+       movl    8(%esp), %ecx           #; Load address of operand
+       lock
+       xaddl   %eax, 0(%ecx)           #; Atomic exchange and add
+       ret