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dvma.c revision 1.10 
      1 /*	$NetBSD: dvma.c,v 1.10 2003/11/10 08:51:52 wiz 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  * 3. The name of the author may not be used to endorse or promote products
     15  *    derived from this software without specific prior written permission.
     16  * 4. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *      This product includes software developed by Gordon Ross
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * The easiest way to deal with the need for DVMA mappings is to just
     34  * map the entire megabyte of RAM where we are loaded into DVMA space.
     35  * That way, dvma_mapin can just compute the DVMA alias address, and
     36  * dvma_mapout does nothing.  Note that this assumes all standalone
     37  * programs stay in the range `base_va' .. `base_va + DVMA_MAPLEN'
     38  */
     39 
     40 #include <sys/param.h>
     41 #include <sparc/sparc/asm.h>
     42 #include <machine/pte.h>
     43 #include <machine/ctlreg.h>
     44 
     45 #include <lib/libsa/stand.h>
     46 #include <sparc/stand/common/promdev.h>
     47 
     48 #define	DVMA_BASE	0xFFF00000
     49 #define DVMA_MAPLEN	0xE0000	/* 1 MB - 128K (save MONSHORTSEG) */
     50 
     51 static int base_va;
     52 
     53 /*
     54  * This module is only used on sun4, so:
     55  */
     56 #define	getsegmap(va)		(lduha(va, ASI_SEGMAP))
     57 #define	setsegmap(va, pmeg)	do stha(va, ASI_SEGMAP, pmeg); while(0)
     58 
     59 void
     60 dvma_init()
     61 {
     62 	u_int segva, dmava;
     63 	int nseg;
     64 	extern int start;
     65 
     66 	/*
     67 	 * Align our address base with the DVMA segment.
     68 	 * Allocate one DVMA segment to cover the stack, which
     69 	 * grows downward from `start'.
     70 	 */
     71 	dmava = DVMA_BASE;
     72 	base_va = segva = (((int)&start) & -NBPSG) - NBPSG;
     73 
     74 	/* Then double-map the DVMA addresses */
     75 	nseg = (DVMA_MAPLEN + NBPSG - 1) >> SGSHIFT;
     76 	while (nseg-- > 0) {
     77 		setsegmap(dmava, getsegmap(segva));
     78 		segva += NBPSG;
     79 		dmava += NBPSG;
     80 	}
     81 }
     82 
     83 /*
     84  * Convert a local address to a DVMA address.
     85  */
     86 char *
     87 dvma_mapin(addr, len)
     88 	char *addr;
     89 	size_t len;
     90 {
     91 	int va = (int)addr;
     92 
     93 	va -= base_va;
     94 
     95 #ifndef BOOTXX
     96 	/* Make sure the address is in the DVMA map. */
     97 	if (va < 0 || va >= DVMA_MAPLEN)
     98 		panic("dvma_mapin: va %x (DMA base %x)", va+base_va, base_va);
     99 #endif
    100 
    101 	va += DVMA_BASE;
    102 
    103 	return ((char *)va);
    104 }
    105 
    106 /*
    107  * Convert a DVMA address to a local address.
    108  */
    109 char *
    110 dvma_mapout(addr, len)
    111 	char *addr;
    112 	size_t len;
    113 {
    114 	int va = (int)addr;
    115 
    116 	va -= DVMA_BASE;
    117 
    118 #ifndef BOOTXX
    119 	/* Make sure the address is in the DVMA map. */
    120 	if (va < 0 || va >= DVMA_MAPLEN)
    121 		panic("dvma_mapout: va %x (DMA base %x)", va+base_va, base_va);
    122 #endif
    123 
    124 	va += base_va;
    125 
    126 	return ((char *)va);
    127 }
    128 
    129 char *
    130 dvma_alloc(len)
    131 	int len;
    132 {
    133 	char *mem;
    134 
    135 	mem = alloc(len);
    136 	if (mem == NULL)
    137 		return (mem);
    138 	return (dvma_mapin(mem, len));
    139 }
    140 
    141 void
    142 dvma_free(dvma, len)
    143 	char *dvma;
    144 	int len;
    145 {
    146 	char *mem;
    147 
    148 	mem = dvma_mapout(dvma, len);
    149 	if (mem != NULL)
    150 		free(mem, len);
    151 }
    152