osfmk/ppc/commpage/mach_absolute_time.s

   1 /*
   2  * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25
  26 #define ASSEMBLER
  27 #include <sys/appleapiopts.h>
  28 #include <ppc/asm.h>                                    // EXT, LEXT
  29 #include <machine/cpu_capabilities.h>
  30 #include <machine/commpage.h>
  31
  32         .text
  33         .align  2
  34         .globl  EXT(mach_absolute_time_32)
  35         .globl  EXT(mach_absolute_time_64)
  36
  37
  38 // *********************************************
  39 // * M A C H _ A B S O L U T E _ T I M E _ 3 2 *
  40 // *********************************************
  41
  42 mach_absolute_time_32:
  43 1:
  44         mftbu   r3
  45         mftb    r4
  46         mftbu   r5
  47         cmplw   r3,r5
  48         beqlr+
  49         b               1b
  50
  51         COMMPAGE_DESCRIPTOR(mach_absolute_time_32,_COMM_PAGE_ABSOLUTE_TIME,0,k64Bit,0)
  52
  53
  54 // *********************************************
  55 // * M A C H _ A B S O L U T E _ T I M E _ 6 4 *
  56 // *********************************************
  57 //
  58 // Why bother to special case for 64-bit?  Because the "mftb" variants
  59 // are 10 cycles each, and they are serialized.
  60
  61 mach_absolute_time_64:
  62         mftb    r4
  63         srdi    r3,r4,32
  64         blr
  65
  66         COMMPAGE_DESCRIPTOR(mach_absolute_time_64,_COMM_PAGE_ABSOLUTE_TIME,k64Bit,0,0)
  67
  68