osfmk/i386/hi_res_clock_map.c

   1 /*
   2  * Copyright (c) 2000 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  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * HISTORY
  30  *
  31  * Revision 1.1.1.1  1998/09/22 21:05:36  wsanchez
  32  * Import of Mac OS X kernel (~semeria)
  33  *
  34  * Revision 1.1.1.1  1998/03/07 02:25:37  wsanchez
  35  * Import of OSF Mach kernel (~mburg)
  36  *
  37  * Revision 1.1.7.1  1994/09/23  01:54:44  ezf
  38  *      change marker to not FREE
  39  *      [1994/09/22  21:23:10  ezf]
  40  *
  41  * Revision 1.1.2.2  1993/08/24  09:39:55  rod
  42  *      Created for iX86 common high resolution clock common code.  CR #9400.
  43  *      [1993/08/17  11:26:08  rod]
  44  *
  45  * $EndLog$
  46  */
  47
  48 #include <vm/pmap.h>
  49 #include <i386/hi_res_clock.h>
  50
  51 extern int *high_res_clock;
  52
  53 vm_offset_t
  54 hi_res_clk_mmap(
  55         dev_t           dev,
  56         vm_offset_t     off,
  57         int             prot)
  58 {
  59                if (prot & VM_PROT_WRITE) return (-1);
  60                return (i386_btop(pmap_extract(pmap_kernel(),
  61                                               (vm_offset_t) high_res_clock)));
  62 }