boot/sparc/dvma.c

   1 /*      $OpenBSD: dvma.c,v 1.1 1997/09/17 10:46:18 downsj Exp $ */
   2 /*      $NetBSD: dvma.c,v 1.2 1995/09/17 00:50:56 pk Exp $      */
   3 /*
   4  * Copyright (c) 1995 Gordon W. Ross
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  * 4. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by Gordon Ross
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * The easiest way to deal with the need for DVMA mappings is
  35  * to just map the entire third megabyte of RAM into DVMA space.
  36  * That way, dvma_mapin can just compute the DVMA alias address,
  37  * and dvma_mapout does nothing.  Note that this assumes all
  38  * standalone programs stay in the range SA_MIN_VA .. SA_MAX_VA
  39  */
  40
  41 #include <sys/param.h>
  42 #include <machine/pte.h>
  43 #include <machine/ctlreg.h>
  44
  45 #include <promdev.h>
  46
  47 #define DVMA_BASE       0xFFF00000
  48 #define DVMA_MAPLEN     0xE0000 /* 1 MB - 128K (save MONSHORTSEG) */
  49
  50 #define SA_MIN_VA       (RELOC - 0x40000)       /* XXX - magic constant */
  51 #define SA_MAX_VA       (SA_MIN_VA + DVMA_MAPLEN)
  52
  53 void
  54 dvma_init()
  55 {
  56         register int segva, dmava;
  57
  58         dmava = DVMA_BASE;
  59         for (segva = SA_MIN_VA; segva < SA_MAX_VA; segva += NBPSG) {
  60                 setsegmap(dmava, getsegmap(segva));
  61                 dmava += NBPSG;
  62         }
  63 }
  64
  65 /*
  66  * Convert a local address to a DVMA address.
  67  */
  68 char *
  69 dvma_mapin(char *addr, size_t len)
  70 {
  71         register int va = (int)addr;
  72
  73         /* Make sure the address is in the DVMA map. */
  74         if ((va < SA_MIN_VA) || (va >= SA_MAX_VA))
  75                 panic("dvma_mapin");
  76
  77         va += DVMA_BASE - SA_MIN_VA;
  78
  79         return ((char *)va);
  80 }
  81
  82 /*
  83  * Convert a DVMA address to a local address.
  84  */
  85 char *
  86 dvma_mapout(char *addr, size_t len)
  87 {
  88         int va = (int)addr;
  89
  90         /* Make sure the address is in the DVMA map. */
  91         if ((va < DVMA_BASE) || (va >= (DVMA_BASE + DVMA_MAPLEN)))
  92                 panic("dvma_mapout");
  93
  94         va -= DVMA_BASE - SA_MIN_VA;
  95
  96         return ((char *)va);
  97 }
  98
  99 extern char *alloc __P((int));
 100
 101 char *
 102 dvma_alloc(int len)
 103 {
 104         char *mem;
 105
 106         mem = alloc(len);
 107         if (!mem)
 108                 return (mem);
 109         return (dvma_mapin(mem, len));
 110 }
 111
 112 extern void free(void *ptr, int len);
 113 void
 114 dvma_free(char *dvma, int len)
 115 {
 116         char *mem;
 117
 118         mem = dvma_mapout(dvma, len);
 119         if (mem)
 120                 free(mem, len);
 121 }
 122