xref: /netbsd-src/sys/arch/sparc/stand/common/dvma.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: dvma.c,v 1.1 1997/06/01 03:39:33 mrg 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
34  * to just map the entire third megabyte of RAM into DVMA space.
35  * That way, dvma_mapin can just compute the DVMA alias address,
36  * and dvma_mapout does nothing.  Note that this assumes all
37  * standalone programs stay in the range SA_MIN_VA .. SA_MAX_VA
38  */
39 
40 #include <sys/param.h>
41 #include <machine/pte.h>
42 #include <machine/ctlreg.h>
43 
44 #include <sparc/stand/common/promdev.h>
45 
46 #define	DVMA_BASE	0xFFF00000
47 #define DVMA_MAPLEN	0xE0000	/* 1 MB - 128K (save MONSHORTSEG) */
48 
49 #define SA_MIN_VA	(RELOC - 0x40000)	/* XXX - magic constant */
50 #define SA_MAX_VA	(SA_MIN_VA + DVMA_MAPLEN)
51 
52 void
53 dvma_init()
54 {
55 	register int segva, dmava;
56 
57 	dmava = DVMA_BASE;
58 	for (segva = SA_MIN_VA; segva < SA_MAX_VA; segva += NBPSG) {
59 		setsegmap(dmava, getsegmap(segva));
60 		dmava += NBPSG;
61 	}
62 }
63 
64 /*
65  * Convert a local address to a DVMA address.
66  */
67 char *
68 dvma_mapin(char *addr, size_t len)
69 {
70 	register int va = (int)addr;
71 
72 	/* Make sure the address is in the DVMA map. */
73 	if ((va < SA_MIN_VA) || (va >= SA_MAX_VA))
74 		panic("dvma_mapin");
75 
76 	va += DVMA_BASE - SA_MIN_VA;
77 
78 	return ((char *)va);
79 }
80 
81 /*
82  * Convert a DVMA address to a local address.
83  */
84 char *
85 dvma_mapout(char *addr, size_t len)
86 {
87 	int va = (int)addr;
88 
89 	/* Make sure the address is in the DVMA map. */
90 	if ((va < DVMA_BASE) || (va >= (DVMA_BASE + DVMA_MAPLEN)))
91 		panic("dvma_mapout");
92 
93 	va -= DVMA_BASE - SA_MIN_VA;
94 
95 	return ((char *)va);
96 }
97 
98 extern char *alloc __P((int));
99 
100 char *
101 dvma_alloc(int len)
102 {
103 	char *mem;
104 
105 	mem = alloc(len);
106 	if (!mem)
107 		return (mem);
108 	return (dvma_mapin(mem, len));
109 }
110 
111 extern void free(void *ptr, int len);
112 void
113 dvma_free(char *dvma, int len)
114 {
115 	char *mem;
116 
117 	mem = dvma_mapout(dvma, len);
118 	if (mem)
119 		free(mem, len);
120 }
121