FreeBSD/Linux Kernel Cross Reference
sys/mach/vm_param.h

     /* 
      * Mach Operating System
      * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
      * All Rights Reserved.
      * 
      * Permission to use, copy, modify and distribute this software and its
      * documentation is hereby granted, provided that both the copyright
      * notice and this permission notice appear in all copies of the
      * software, derivative works or modified versions, and any portions
     * thereof, and that both notices appear in supporting documentation.
     * 
     * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
     * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     * 
     * Carnegie Mellon requests users of this software to return to
     * 
     *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
     *  School of Computer Science
     *  Carnegie Mellon University
     *  Pittsburgh PA 15213-3890
     * 
     * any improvements or extensions that they make and grant Carnegie Mellon
     * the rights to redistribute these changes.
     */
    /*
     * HISTORY
     * $Log:        vm_param.h,v $
     * Revision 2.5  93/01/14  17:49:06  danner
     *      Standardized include symbol name.
     *      [92/06/10            pds]
     *      64bit cleanup.
     *      [92/12/01            af]
     * 
     * Revision 2.4  91/05/14  17:02:53  mrt
     *      Correcting copyright
     * 
     * Revision 2.3  91/02/05  17:37:34  mrt
     *      Changed to new Mach copyright
     *      [91/02/01  17:22:32  mrt]
     * 
     * Revision 2.2  90/06/02  15:00:23  rpd
     *      Removed user definitions; added page_aligned.
     *      [90/03/26  22:42:42  rpd]
     * 
     * Revision 2.1  89/08/03  16:06:40  rwd
     * Created.
     * 
     * Revision 2.3  89/02/25  18:42:23  gm0w
     *      Changes for cleanup.
     * 
     * 15-May-87  Avadis Tevanian (avie) at Carnegie-Mellon University
     *      Coalesced includes, documented use of PAGE_SIZE and PAGE_SHIFT.
     *
     * 15-Nov-86  Avadis Tevanian (avie) at Carnegie-Mellon University
     *      Removed include of <mach_init.h> before non-kernel definitions
     *      of trunc/round page macros.  When this is included, it makes it
     *      impossible for user programs to include system header files to
     *      retrieve kernel data structures.  (For example, the user level
     *      mach_init will cause a task to be a port, making it impossible
     *      to get the real kernel definition of a task).
     *
     *  7-Nov-86  Michael Young (mwyoung) at Carnegie-Mellon University
     *      Added non-KERNEL definitions of round_page, trunc_page.
     *
     * 21-May-86  David Golub (dbg) at Carnegie-Mellon University
     *      Added page_mask.  Changed types of page_size and page_mask
     *      to vm_size_t.
     *
     *  9-Jun-85  Avadis Tevanian (avie) at Carnegie-Mellon University
     *      Created.
     *
     */
    /*
     *      File:   mach/vm_param.h
     *      Author: Avadis Tevanian, Jr., Michael Wayne Young
     *      Date:   1985
     *
     *      Machine independent virtual memory parameters.
     *
     */
    
    #ifndef _MACH_VM_PARAM_H_
    #define _MACH_VM_PARAM_H_
    
    #ifndef KERNEL
    
    ;YOU HAVE MADE A MISTAKE BY INCLUDING THIS FILE;
    
    THIS FILE SHOULD NOT BE VISIBLE TO USER PROGRAMS.
    
    USE <mach/machine/vm_param.h> TO GET MACHINE-DEPENDENT ADDRESS
    SPACE AND PAGE SIZE ITEMS.
    
    USE <mach/machine/vm_types.h> TO GET TYPE DECLARATIONS USED IN
    THE MACH KERNEL INTERFACE.
    
    IN ALL PROBABILITY, YOU SHOULD GET ALL OF THE TYPES USED IN THE
    INTERFACE FROM <mach/mach_types.h>
   
   #endif  /* KERNEL */
   
   #include <mach/machine/vm_param.h>
   #include <mach/machine/vm_types.h>
   
   /*
    *      The machine independent pages are refered to as PAGES.  A page
    *      is some number of hardware pages, depending on the target machine.
    */
   
   /*
    *      All references to the size of a page should be done with PAGE_SIZE
    *      or PAGE_SHIFT.  The fact they are variables is hidden here so that
    *      we can easily make them constant if we so desire.
    */
   
   /*
    *      Regardless whether it is implemented with a constant or a variable,
    *      the PAGE_SIZE is assumed to be a power of two throughout the
    *      virtual memory system implementation.
    */
   
   #ifndef PAGE_SIZE_FIXED
   #define PAGE_SIZE       page_size       /* size of page in addressible units */
   #define PAGE_SHIFT      page_shift      /* number of bits to shift for pages */
   #endif  /* PAGE_SIZE_FIXED */
   
   #ifndef ASSEMBLER
   /*
    *      Convert addresses to pages and vice versa.
    *      No rounding is used.
    */
   
   #define atop(x)         (((vm_size_t)(x)) >> page_shift)
   #define ptoa(x)         ((vm_offset_t)((x) << page_shift))
   
   /*
    *      Round off or truncate to the nearest page.  These will work
    *      for either addresses or counts.  (i.e. 1 byte rounds to 1 page
    *      bytes.
    */
   
   #define round_page(x)   ((vm_offset_t)((((vm_offset_t)(x)) + page_mask) & ~page_mask))
   #define trunc_page(x)   ((vm_offset_t)(((vm_offset_t)(x)) & ~page_mask))
   
   /*
    *      Determine whether an address is page-aligned, or a count is
    *      an exact page multiple.
    */
   
   #define page_aligned(x) ((((vm_offset_t) (x)) & page_mask) == 0)
   
   #ifndef PAGE_SIZE_FIXED
   extern vm_size_t        page_size;      /* machine independent page size */
   extern vm_size_t        page_mask;      /* page_size - 1; mask for
                                                      offset within page */
   extern int              page_shift;     /* shift to use for page size */
   #else   /* PAGE_SIZE_FIXED */
   #define page_mask       (PAGE_SIZE-1)
   #endif  /* PAGE_SIZE_FIXED */
   
   extern vm_size_t        mem_size;       /* size of physical memory (bytes) */
   extern vm_offset_t      first_addr;     /* first physical page */
   extern vm_offset_t      last_addr;      /* last physical page */
   
   #endif  /* ASSEMBLER */
   #endif  /* _MACH_VM_PARAM_H_ */

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