tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) Paul Mackerras 1997.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9#include <stdarg.h>
10#include <stddef.h>
11#include "string.h"
12#include "stdio.h"
13#include "prom.h"
14
15int (*prom)(void *);
16phandle chosen_handle;
17ihandle stdout;
18
19int call_prom(const char *service, int nargs, int nret, ...)
20{
21 int i;
22 struct prom_args {
23 const char *service;
24 int nargs;
25 int nret;
26 unsigned int args[12];
27 } args;
28 va_list list;
29
30 args.service = service;
31 args.nargs = nargs;
32 args.nret = nret;
33
34 va_start(list, nret);
35 for (i = 0; i < nargs; i++)
36 args.args[i] = va_arg(list, unsigned int);
37 va_end(list);
38
39 for (i = 0; i < nret; i++)
40 args.args[nargs+i] = 0;
41
42 if (prom(&args) < 0)
43 return -1;
44
45 return (nret > 0)? args.args[nargs]: 0;
46}
47
48int call_prom_ret(const char *service, int nargs, int nret,
49 unsigned int *rets, ...)
50{
51 int i;
52 struct prom_args {
53 const char *service;
54 int nargs;
55 int nret;
56 unsigned int args[12];
57 } args;
58 va_list list;
59
60 args.service = service;
61 args.nargs = nargs;
62 args.nret = nret;
63
64 va_start(list, rets);
65 for (i = 0; i < nargs; i++)
66 args.args[i] = va_arg(list, unsigned int);
67 va_end(list);
68
69 for (i = 0; i < nret; i++)
70 args.args[nargs+i] = 0;
71
72 if (prom(&args) < 0)
73 return -1;
74
75 if (rets != (void *) 0)
76 for (i = 1; i < nret; ++i)
77 rets[i-1] = args.args[nargs+i];
78
79 return (nret > 0)? args.args[nargs]: 0;
80}
81
82int write(void *handle, void *ptr, int nb)
83{
84 return call_prom("write", 3, 1, handle, ptr, nb);
85}
86
87/*
88 * Older OF's require that when claiming a specific range of addresses,
89 * we claim the physical space in the /memory node and the virtual
90 * space in the chosen mmu node, and then do a map operation to
91 * map virtual to physical.
92 */
93static int need_map = -1;
94static ihandle chosen_mmu;
95static phandle memory;
96
97/* returns true if s2 is a prefix of s1 */
98static int string_match(const char *s1, const char *s2)
99{
100 for (; *s2; ++s2)
101 if (*s1++ != *s2)
102 return 0;
103 return 1;
104}
105
106static int check_of_version(void)
107{
108 phandle oprom, chosen;
109 char version[64];
110
111 oprom = finddevice("/openprom");
112 if (oprom == (phandle) -1)
113 return 0;
114 if (getprop(oprom, "model", version, sizeof(version)) <= 0)
115 return 0;
116 version[sizeof(version)-1] = 0;
117 printf("OF version = '%s'\r\n", version);
118 if (!string_match(version, "Open Firmware, 1.")
119 && !string_match(version, "FirmWorks,3."))
120 return 0;
121 chosen = finddevice("/chosen");
122 if (chosen == (phandle) -1) {
123 chosen = finddevice("/chosen@0");
124 if (chosen == (phandle) -1) {
125 printf("no chosen\n");
126 return 0;
127 }
128 }
129 if (getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
130 printf("no mmu\n");
131 return 0;
132 }
133 memory = (ihandle) call_prom("open", 1, 1, "/memory");
134 if (memory == (ihandle) -1) {
135 memory = (ihandle) call_prom("open", 1, 1, "/memory@0");
136 if (memory == (ihandle) -1) {
137 printf("no memory node\n");
138 return 0;
139 }
140 }
141 printf("old OF detected\r\n");
142 return 1;
143}
144
145void *claim(unsigned long virt, unsigned long size, unsigned long align)
146{
147 int ret;
148 unsigned int result;
149
150 if (need_map < 0)
151 need_map = check_of_version();
152 if (align || !need_map)
153 return (void *) call_prom("claim", 3, 1, virt, size, align);
154
155 ret = call_prom_ret("call-method", 5, 2, &result, "claim", memory,
156 align, size, virt);
157 if (ret != 0 || result == -1)
158 return (void *) -1;
159 ret = call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
160 align, size, virt);
161 /* 0x12 == coherent + read/write */
162 ret = call_prom("call-method", 6, 1, "map", chosen_mmu,
163 0x12, size, virt, virt);
164 return (void *) virt;
165}