Linux Kernel  3.7.1
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oflib.c
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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 <stddef.h>
10 #include "types.h"
11 #include "elf.h"
12 #include "string.h"
13 #include "stdio.h"
14 #include "page.h"
15 #include "ops.h"
16 
17 #include "of.h"
18 
19 static int (*prom) (void *);
20 
21 void of_init(void *promptr)
22 {
23  prom = (int (*)(void *))promptr;
24 }
25 
26 int of_call_prom(const char *service, int nargs, int nret, ...)
27 {
28  int i;
29  struct prom_args {
30  const char *service;
31  int nargs;
32  int nret;
33  unsigned int args[12];
34  } args;
35  va_list list;
36 
37  args.service = service;
38  args.nargs = nargs;
39  args.nret = nret;
40 
41  va_start(list, nret);
42  for (i = 0; i < nargs; i++)
43  args.args[i] = va_arg(list, unsigned int);
44  va_end(list);
45 
46  for (i = 0; i < nret; i++)
47  args.args[nargs+i] = 0;
48 
49  if (prom(&args) < 0)
50  return -1;
51 
52  return (nret > 0)? args.args[nargs]: 0;
53 }
54 
55 static int of_call_prom_ret(const char *service, int nargs, int nret,
56  unsigned int *rets, ...)
57 {
58  int i;
59  struct prom_args {
60  const char *service;
61  int nargs;
62  int nret;
63  unsigned int args[12];
64  } args;
65  va_list list;
66 
67  args.service = service;
68  args.nargs = nargs;
69  args.nret = nret;
70 
71  va_start(list, rets);
72  for (i = 0; i < nargs; i++)
73  args.args[i] = va_arg(list, unsigned int);
74  va_end(list);
75 
76  for (i = 0; i < nret; i++)
77  args.args[nargs+i] = 0;
78 
79  if (prom(&args) < 0)
80  return -1;
81 
82  if (rets != (void *) 0)
83  for (i = 1; i < nret; ++i)
84  rets[i-1] = args.args[nargs+i];
85 
86  return (nret > 0)? args.args[nargs]: 0;
87 }
88 
89 /* returns true if s2 is a prefix of s1 */
90 static int string_match(const char *s1, const char *s2)
91 {
92  for (; *s2; ++s2)
93  if (*s1++ != *s2)
94  return 0;
95  return 1;
96 }
97 
98 /*
99  * Older OF's require that when claiming a specific range of addresses,
100  * we claim the physical space in the /memory node and the virtual
101  * space in the chosen mmu node, and then do a map operation to
102  * map virtual to physical.
103  */
104 static int need_map = -1;
105 static ihandle chosen_mmu;
106 static phandle memory;
107 
108 static int check_of_version(void)
109 {
110  phandle oprom, chosen;
111  char version[64];
112 
113  oprom = of_finddevice("/openprom");
114  if (oprom == (phandle) -1)
115  return 0;
116  if (of_getprop(oprom, "model", version, sizeof(version)) <= 0)
117  return 0;
118  version[sizeof(version)-1] = 0;
119  printf("OF version = '%s'\r\n", version);
120  if (!string_match(version, "Open Firmware, 1.")
121  && !string_match(version, "FirmWorks,3."))
122  return 0;
123  chosen = of_finddevice("/chosen");
124  if (chosen == (phandle) -1) {
125  chosen = of_finddevice("/chosen@0");
126  if (chosen == (phandle) -1) {
127  printf("no chosen\n");
128  return 0;
129  }
130  }
131  if (of_getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
132  printf("no mmu\n");
133  return 0;
134  }
135  memory = (ihandle) of_call_prom("open", 1, 1, "/memory");
136  if (memory == (ihandle) -1) {
137  memory = (ihandle) of_call_prom("open", 1, 1, "/memory@0");
138  if (memory == (ihandle) -1) {
139  printf("no memory node\n");
140  return 0;
141  }
142  }
143  printf("old OF detected\r\n");
144  return 1;
145 }
146 
147 void *of_claim(unsigned long virt, unsigned long size, unsigned long align)
148 {
149  int ret;
150  unsigned int result;
151 
152  if (need_map < 0)
153  need_map = check_of_version();
154  if (align || !need_map)
155  return (void *) of_call_prom("claim", 3, 1, virt, size, align);
156 
157  ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", memory,
158  align, size, virt);
159  if (ret != 0 || result == -1)
160  return (void *) -1;
161  ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
162  align, size, virt);
163  /* 0x12 == coherent + read/write */
164  ret = of_call_prom("call-method", 6, 1, "map", chosen_mmu,
165  0x12, size, virt, virt);
166  return (void *) virt;
167 }
168 
169 void *of_vmlinux_alloc(unsigned long size)
170 {
171  unsigned long start = (unsigned long)_start, end = (unsigned long)_end;
172  void *addr;
173  void *p;
174 
175  /* With some older POWER4 firmware we need to claim the area the kernel
176  * will reside in. Newer firmwares don't need this so we just ignore
177  * the return value.
178  */
179  addr = of_claim(start, end - start, 0);
180  printf("Trying to claim from 0x%lx to 0x%lx (0x%lx) got %p\r\n",
181  start, end, end - start, addr);
182 
183  p = malloc(size);
184  if (!p)
185  fatal("Can't allocate memory for kernel image!\n\r");
186 
187  return p;
188 }
189 
190 void of_exit(void)
191 {
192  of_call_prom("exit", 0, 0);
193 }
194 
195 /*
196  * OF device tree routines
197  */
198 void *of_finddevice(const char *name)
199 {
200  return (phandle) of_call_prom("finddevice", 1, 1, name);
201 }
202 
203 int of_getprop(const void *phandle, const char *name, void *buf,
204  const int buflen)
205 {
206  return of_call_prom("getprop", 4, 1, phandle, name, buf, buflen);
207 }
208 
209 int of_setprop(const void *phandle, const char *name, const void *buf,
210  const int buflen)
211 {
212  return of_call_prom("setprop", 4, 1, phandle, name, buf, buflen);
213 }