xref: /netbsd-src/sys/arch/sparc/stand/common/dvma.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
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  * 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(void)
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(char *addr, size_t len)
88 {
89 	int va = (int)addr;
90 
91 	va -= base_va;
92 
93 #ifndef BOOTXX
94 	/* Make sure the address is in the DVMA map. */
95 	if (va < 0 || va >= DVMA_MAPLEN)
96 		panic("dvma_mapin: va %x (DMA base %x)", va+base_va, base_va);
97 #endif
98 
99 	va += DVMA_BASE;
100 
101 	return ((char *)va);
102 }
103 
104 /*
105  * Convert a DVMA address to a local address.
106  */
107 char *
108 dvma_mapout(char *addr, size_t len)
109 {
110 	int va = (int)addr;
111 
112 	va -= DVMA_BASE;
113 
114 #ifndef BOOTXX
115 	/* Make sure the address is in the DVMA map. */
116 	if (va < 0 || va >= DVMA_MAPLEN)
117 		panic("dvma_mapout: va %x (DMA base %x)", va+base_va, base_va);
118 #endif
119 
120 	va += base_va;
121 
122 	return ((char *)va);
123 }
124 
125 char *
126 dvma_alloc(int len)
127 {
128 	char *mem;
129 
130 	mem = alloc(len);
131 	if (mem == NULL)
132 		return (mem);
133 	return (dvma_mapin(mem, len));
134 }
135 
136 void
137 dvma_free(char *dvma, int len)
138 {
139 	char *mem;
140 
141 	mem = dvma_mapout(dvma, len);
142 	if (mem != NULL)
143 		dealloc(mem, len);
144 }
145