sys/arch/sparc/stand/common/dvma.c

   1 /*      $NetBSD: dvma.c,v 1.14 2006/07/13 20:03:34 uwe Exp $    */
   2 /*
   3  * Copyright (c) 1995 Gordon W. Ross
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 /*
  28  * The easiest way to deal with the need for DVMA mappings is to just
  29  * map the entire megabyte of RAM where we are loaded into DVMA space.
  30  * That way, dvma_mapin can just compute the DVMA alias address, and
  31  * dvma_mapout does nothing.  Note that this assumes all standalone
  32  * programs stay in the range `base_va' .. `base_va + DVMA_MAPLEN'
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sparc/sparc/asm.h>
  37 #include <machine/pte.h>
  38 #include <machine/ctlreg.h>
  39
  40 #include <lib/libsa/stand.h>
  41 #include <sparc/stand/common/promdev.h>
  42
  43 #define DVMA_BASE       0xFFF00000
  44 #define DVMA_MAPLEN     0xE0000 /* 1 MB - 128K (save MONSHORTSEG) */
  45
  46 static int base_va;
  47
  48 /*
  49  * This module is only used on sun4, so:
  50  */
  51 #define getsegmap(va)           (lduha(va, ASI_SEGMAP))
  52 #define setsegmap(va, pmeg)     do stha(va, ASI_SEGMAP, pmeg); while(0)
  53
  54 void
  55 dvma_init(void)
  56 {
  57         u_int segva, dmava;
  58         int nseg;
  59         extern int start;
  60
  61         /*
  62          * Align our address base with the DVMA segment.
  63          * Allocate one DVMA segment to cover the stack, which
  64          * grows downward from `start'.
  65          */
  66         dmava = DVMA_BASE;
  67         base_va = segva = (((int)&start) & -NBPSG) - NBPSG;
  68
  69         /* Then double-map the DVMA addresses */
  70         nseg = (DVMA_MAPLEN + NBPSG - 1) >> SGSHIFT;
  71         while (nseg-- > 0) {
  72                 setsegmap(dmava, getsegmap(segva));
  73                 segva += NBPSG;
  74                 dmava += NBPSG;
  75         }
  76 }
  77
  78 /*
  79  * Convert a local address to a DVMA address.
  80  */
  81 char *
  82 dvma_mapin(char *addr, size_t len)
  83 {
  84         int va = (int)addr;
  85
  86         va -= base_va;
  87
  88 #ifndef BOOTXX
  89         /* Make sure the address is in the DVMA map. */
  90         if (va < 0 || va >= DVMA_MAPLEN)
  91                 panic("dvma_mapin: va %x (DMA base %x)", va+base_va, base_va);
  92 #endif
  93
  94         va += DVMA_BASE;
  95
  96         return ((char *)va);
  97 }
  98
  99 /*
 100  * Convert a DVMA address to a local address.
 101  */
 102 char *
 103 dvma_mapout(char *addr, size_t len)
 104 {
 105         int va = (int)addr;
 106
 107         va -= DVMA_BASE;
 108
 109 #ifndef BOOTXX
 110         /* Make sure the address is in the DVMA map. */
 111         if (va < 0 || va >= DVMA_MAPLEN)
 112                 panic("dvma_mapout: va %x (DMA base %x)", va+base_va, base_va);
 113 #endif
 114
 115         va += base_va;
 116
 117         return ((char *)va);
 118 }
 119
 120 char *
 121 dvma_alloc(int len)
 122 {
 123         char *mem;
 124
 125         mem = alloc(len);
 126         if (mem == NULL)
 127                 return (mem);
 128         return (dvma_mapin(mem, len));
 129 }
 130
 131 void
 132 dvma_free(char *dvma, int len)
 133 {
 134         char *mem;
 135
 136         mem = dvma_mapout(dvma, len);
 137         if (mem != NULL)
 138                 dealloc(mem, len);
 139 }