1 /* $NetBSD: dvma.c,v 1.15 2009/10/21 23:12:09 snj 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 } 140