text: /*	$OpenBSD: dvma.c,v 1.3 2003/08/14 17:13:57 deraadt Exp $	*/
  /*	$NetBSD: dvma.c,v 1.2 1995/09/17 00:50:56 pk Exp $	*/
  /*
   * Copyright (c) 1995 Gordon W. Ross
   * All rights reserved.
   *
   * 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. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   * 4. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *      This product includes software developed by Gordon Ross
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
   */
  
  /*
   * The easiest way to deal with the need for DVMA mappings is
   * to just map the entire third megabyte of RAM into DVMA space.
   * That way, dvma_mapin can just compute the DVMA alias address,
   * and dvma_mapout does nothing.  Note that this assumes all
   * standalone programs stay in the range SA_MIN_VA .. SA_MAX_VA
   */
  
  #include <sys/param.h>
  #include <machine/pte.h>
  #include <machine/ctlreg.h>
  
  #include <sparc/stand/common/promdev.h>
  
  #define	DVMA_BASE	0xFFF00000
  #define DVMA_MAPLEN	0xE0000	/* 1 MB - 128K (save MONSHORTSEG) */
  
  #define SA_MIN_VA	(RELOC - 0x40000)	/* XXX - magic constant */
  #define SA_MAX_VA	(SA_MIN_VA + DVMA_MAPLEN)
  
  void
  dvma_init(void)
  {
  	register int segva, dmava;
  
  	dmava = DVMA_BASE;
  	for (segva = SA_MIN_VA; segva < SA_MAX_VA; segva += NBPSG) {
  		setsegmap(dmava, getsegmap(segva));
  		dmava += NBPSG;
  	}
  }
  
  /*
   * Convert a local address to a DVMA address.
   */
  char *
  dvma_mapin(char *addr, size_t len)
  {
  	register int va = (int)addr;
  
  	/* Make sure the address is in the DVMA map. */
  	if ((va < SA_MIN_VA) || (va >= SA_MAX_VA))
  		panic("dvma_mapin");
  
  	va += DVMA_BASE - SA_MIN_VA;
  
  	return ((char *)va);
  }
  
  /*
   * Convert a DVMA address to a local address.
   */
  char *
  dvma_mapout(char *addr, size_t len)
  {
  	int va = (int)addr;
  
  	/* Make sure the address is in the DVMA map. */
  	if ((va < DVMA_BASE) || (va >= (DVMA_BASE + DVMA_MAPLEN)))
  		panic("dvma_mapout");
  
  	va -= DVMA_BASE - SA_MIN_VA;
  
  	return ((char *)va);
  }
  
  extern char *alloc(int);
  
  char *
  dvma_alloc(int len)
  {
  	char *mem;
  
  	mem = alloc(len);
  	if (!mem)
  		return (mem);
  	return (dvma_mapin(mem, len));
  }
  
  extern void free(void *ptr, int len);
  void
  dvma_free(char *dvma, int len)
  {
  	char *mem;
  
  	mem = dvma_mapout(dvma, len);
  	if (mem)
  		free(mem, len);
  }
  