FreeBSD/Linux Kernel Cross Reference
sys/i386/include/param.h

     /*-
      * SPDX-License-Identifier: BSD-3-Clause
      *
      * Copyright (c) 1990 The Regents of the University of California.
      * All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * William Jolitz.
      *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      from: @(#)param.h       5.8 (Berkeley) 6/28/91
     * $FreeBSD: head/sys/i386/include/param.h 343567 2019-01-30 02:07:13Z kib $
     */
    
    
    #ifndef _I386_INCLUDE_PARAM_H_
    #define _I386_INCLUDE_PARAM_H_
    
    #include <machine/_align.h>
    
    /*
     * Machine dependent constants for Intel 386.
     */
    
    
    #define __HAVE_ACPI
    #define __HAVE_PIR
    #define __PCI_REROUTE_INTERRUPT
    
    #ifndef MACHINE
    #define MACHINE         "i386"
    #endif
    #ifndef MACHINE_ARCH
    #define MACHINE_ARCH    "i386"
    #endif
    #define MID_MACHINE     MID_I386
    
    #if defined(SMP) || defined(KLD_MODULE)
    #ifndef MAXCPU
    #define MAXCPU          32
    #endif
    #else
    #define MAXCPU          1
    #endif /* SMP || KLD_MODULE */
    
    #ifndef MAXMEMDOM
    #define MAXMEMDOM       1
    #endif
    
    #define ALIGNBYTES      _ALIGNBYTES
    #define ALIGN(p)        _ALIGN(p)
    /*
     * ALIGNED_POINTER is a boolean macro that checks whether an address
     * is valid to fetch data elements of type t from on this architecture.
     * This does not reflect the optimal alignment, just the possibility
     * (within reasonable limits). 
     */
    #define ALIGNED_POINTER(p, t)   1
    
    /*
     * CACHE_LINE_SIZE is the compile-time maximum cache line size for an
     * architecture.  It should be used with appropriate caution.
     */
    #define CACHE_LINE_SHIFT        6
    #define CACHE_LINE_SIZE         (1 << CACHE_LINE_SHIFT)
    
    #define PAGE_SHIFT      12              /* LOG2(PAGE_SIZE) */
    #define PAGE_SIZE       (1 << PAGE_SHIFT)       /* bytes/page */
    #define PAGE_MASK       (PAGE_SIZE - 1)
    #define NPTEPG          (PAGE_SIZE / sizeof(pt_entry_t))
    
    /* Size in bytes of the page directory */
    #define NBPTD           (NPGPTD << PAGE_SHIFT)
    /* Number of PDEs in page directory, 2048 for PAE, 1024 for non-PAE */
    #define NPDEPTD         (NBPTD / sizeof(pd_entry_t))
    /* Number of PDEs in one page of the page directory, 512 vs. 1024 */
   #define NPDEPG          (PAGE_SIZE / sizeof(pd_entry_t))
   #define PDRMASK         (NBPDR - 1)
   #ifndef PDRSHIFT
   #define PDRSHIFT        i386_pmap_PDRSHIFT
   #endif
   #ifndef NBPDR
   #define NBPDR           (1 << PDRSHIFT) /* bytes/page dir */
   #endif
   
   #define MAXPAGESIZES    2       /* maximum number of supported page sizes */
   
   #define IOPAGES 2               /* pages of i/o permission bitmap */
   
   #ifndef KSTACK_PAGES
   #define KSTACK_PAGES 4          /* Includes pcb! */
   #endif
   #define KSTACK_GUARD_PAGES 1    /* pages of kstack guard; 0 disables */
   #if KSTACK_PAGES < 4
   #define TD0_KSTACK_PAGES 4
   #else
   #define TD0_KSTACK_PAGES KSTACK_PAGES
   #endif
   
   /*
    * Ceiling on amount of swblock kva space, can be changed via
    * the kern.maxswzone /boot/loader.conf variable.
    *
    * 276 is sizeof(struct swblock), but we do not always have a definition
    * in scope for struct swblock, so we have to hardcode it.  Each struct
    * swblock holds metadata for 32 pages, so in theory, this is enough for
    * 16 GB of swap.  In practice, however, the usable amount is considerably
    * lower due to fragmentation.
    */
   #ifndef VM_SWZONE_SIZE_MAX
   #define VM_SWZONE_SIZE_MAX      (276 * 128 * 1024)
   #endif
   
   /*
    * Ceiling on size of buffer cache (really only effects write queueing,
    * the VM page cache is not effected), can be changed via
    * the kern.maxbcache /boot/loader.conf variable.
    *
    * The value is equal to the size of the auto-tuned buffer map for
    * the machine with 4GB of RAM, see vfs_bio.c:kern_vfs_bio_buffer_alloc().
    */
   #ifndef VM_BCACHE_SIZE_MAX
   #define VM_BCACHE_SIZE_MAX      (7224 * 16 * 1024)
   #endif
   
   /*
    * Mach derived conversion macros
    */
   #define trunc_page(x)           ((x) & ~PAGE_MASK)
   #define round_page(x)           (((x) + PAGE_MASK) & ~PAGE_MASK)
   #define trunc_4mpage(x)         ((x) & ~PDRMASK)
   #define round_4mpage(x)         ((((x)) + PDRMASK) & ~PDRMASK)
   
   #define atop(x)                 ((x) >> PAGE_SHIFT)
   #define ptoa(x)                 ((x) << PAGE_SHIFT)
   
   #define i386_btop(x)            ((x) >> PAGE_SHIFT)
   #define i386_ptob(x)            ((x) << PAGE_SHIFT)
   
   #define pgtok(x)                ((x) * (PAGE_SIZE / 1024))
   
   #define INKERNEL(va)            (TRUE)
   
   #endif /* !_I386_INCLUDE_PARAM_H_ */

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