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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * HISTORY
  27  *
  28  * Revision 1.1.1.1  1998/09/22 21:05:36  wsanchez
  29  * Import of Mac OS X kernel (~semeria)
  30  *
  31  * Revision 1.1.1.1  1998/03/07 02:25:37  wsanchez
  32  * Import of OSF Mach kernel (~mburg)
  33  *
  34  * Revision 1.1.7.1  1994/09/23  01:54:44  ezf
  35  *      change marker to not FREE
  36  *      [1994/09/22  21:23:10  ezf]
  37  *
  38  * Revision 1.1.2.2  1993/08/24  09:39:55  rod
  39  *      Created for iX86 common high resolution clock common code.  CR #9400.
  40  *      [1993/08/17  11:26:08  rod]
  41  *
  42  * $EndLog$
  43  */
  44
  45 #include <vm/pmap.h>
  46 #include <i386/hi_res_clock.h>
  47
  48 extern int *high_res_clock;
  49
  50 vm_offset_t
  51 hi_res_clk_mmap(
  52         dev_t           dev,
  53         vm_offset_t     off,
  54         int             prot)
  55 {
  56                if (prot & VM_PROT_WRITE) return (-1);
  57                return (i386_btop(pmap_extract(pmap_kernel(),
  58                                               (vm_offset_t) high_res_clock)));
  59 }