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  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * HISTORY
  28  *
  29  * Revision 1.1.1.1  1998/09/22 21:05:36  wsanchez
  30  * Import of Mac OS X kernel (~semeria)
  31  *
  32  * Revision 1.1.1.1  1998/03/07 02:25:37  wsanchez
  33  * Import of OSF Mach kernel (~mburg)
  34  *
  35  * Revision 1.1.7.1  1994/09/23  01:54:44  ezf
  36  *      change marker to not FREE
  37  *      [1994/09/22  21:23:10  ezf]
  38  *
  39  * Revision 1.1.2.2  1993/08/24  09:39:55  rod
  40  *      Created for iX86 common high resolution clock common code.  CR #9400.
  41  *      [1993/08/17  11:26:08  rod]
  42  *
  43  * $EndLog$
  44  */
  45
  46 #include <vm/pmap.h>
  47 #include <i386/hi_res_clock.h>
  48
  49 extern int *high_res_clock;
  50
  51 vm_offset_t
  52 hi_res_clk_mmap(
  53         dev_t           dev,
  54         vm_offset_t     off,
  55         int             prot)
  56 {
  57                if (prot & VM_PROT_WRITE) return (-1);
  58                return (i386_btop(pmap_extract(pmap_kernel(),
  59                                               (vm_offset_t) high_res_clock)));
  60 }