1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) Paul Mackerras 1997.
4 */
5 #include <stddef.h>
6 #include "types.h"
7 #include "elf.h"
8 #include "string.h"
9 #include "stdio.h"
10 #include "page.h"
11 #include "ops.h"
12
13 #include "of.h"
14
15 typedef u32 prom_arg_t;
16
17 /* The following structure is used to communicate with open firmware.
18 * All arguments in and out are in big endian format. */
19 struct prom_args {
20 __be32 service; /* Address of service name string. */
21 __be32 nargs; /* Number of input arguments. */
22 __be32 nret; /* Number of output arguments. */
23 __be32 args[10]; /* Input/output arguments. */
24 };
25
26 #ifdef __powerpc64__
27 extern int prom(void *);
28 #else
29 static int (*prom) (void *);
30 #endif
31
32 void of_init(void *promptr)
33 {
34 #ifndef __powerpc64__
35 prom = (int (*)(void *))promptr;
36 #endif
37 }
38
39 #define ADDR(x) (u32)(unsigned long)(x)
40
41 int of_call_prom(const char *service, int nargs, int nret, ...)
42 {
43 int i;
44 struct prom_args args;
45 va_list list;
46
47 args.service = cpu_to_be32(ADDR(service));
48 args.nargs = cpu_to_be32(nargs);
49 args.nret = cpu_to_be32(nret);
50
51 va_start(list, nret);
52 for (i = 0; i < nargs; i++)
53 args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
54 va_end(list);
55
56 for (i = 0; i < nret; i++)
57 args.args[nargs+i] = 0;
58
59 if (prom(&args) < 0)
60 return PROM_ERROR;
61
62 return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
63 }
64
65 static int of_call_prom_ret(const char *service, int nargs, int nret,
66 prom_arg_t *rets, ...)
67 {
68 int i;
69 struct prom_args args;
70 va_list list;
71
72 args.service = cpu_to_be32(ADDR(service));
73 args.nargs = cpu_to_be32(nargs);
74 args.nret = cpu_to_be32(nret);
75
76 va_start(list, rets);
77 for (i = 0; i < nargs; i++)
78 args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
79 va_end(list);
80
81 for (i = 0; i < nret; i++)
82 args.args[nargs+i] = 0;
83
84 if (prom(&args) < 0)
85 return PROM_ERROR;
86
87 if (rets != NULL)
88 for (i = 1; i < nret; ++i)
89 rets[i-1] = be32_to_cpu(args.args[nargs+i]);
90
91 return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
92 }
93
94 /* returns true if s2 is a prefix of s1 */
95 static int string_match(const char *s1, const char *s2)
96 {
97 for (; *s2; ++s2)
98 if (*s1++ != *s2)
99 return 0;
100 return 1;
101 }
102
103 /*
104 * Older OF's require that when claiming a specific range of addresses,
105 * we claim the physical space in the /memory node and the virtual
106 * space in the chosen mmu node, and then do a map operation to
107 * map virtual to physical.
108 */
109 static int need_map = -1;
110 static ihandle chosen_mmu;
111 static ihandle memory;
112
113 static int check_of_version(void)
114 {
115 phandle oprom, chosen;
116 char version[64];
117
118 oprom = of_finddevice("/openprom");
119 if (oprom == (phandle) -1)
120 return 0;
121 if (of_getprop(oprom, "model", version, sizeof(version)) <= 0)
122 return 0;
123 version[sizeof(version)-1] = 0;
124 printf("OF version = '%s'\r\n", version);
125 if (!string_match(version, "Open Firmware, 1.")
126 && !string_match(version, "FirmWorks,3."))
127 return 0;
128 chosen = of_finddevice("/chosen");
129 if (chosen == (phandle) -1) {
130 chosen = of_finddevice("/chosen@0");
131 if (chosen == (phandle) -1) {
132 printf("no chosen\n");
133 return 0;
134 }
135 }
136 if (of_getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
137 printf("no mmu\n");
138 return 0;
139 }
140 memory = of_call_prom("open", 1, 1, "/memory");
141 if (memory == PROM_ERROR) {
142 memory = of_call_prom("open", 1, 1, "/memory@0");
143 if (memory == PROM_ERROR) {
144 printf("no memory node\n");
145 return 0;
146 }
147 }
148 printf("old OF detected\r\n");
149 return 1;
150 }
151
152 unsigned int of_claim(unsigned long virt, unsigned long size,
153 unsigned long align)
154 {
155 int ret;
156 prom_arg_t result;
157
158 if (need_map < 0)
159 need_map = check_of_version();
160 if (align || !need_map)
161 return of_call_prom("claim", 3, 1, virt, size, align);
162
163 ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", memory,
164 align, size, virt);
165 if (ret != 0 || result == -1)
166 return -1;
167 ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
168 align, size, virt);
169 /* 0x12 == coherent + read/write */
170 ret = of_call_prom("call-method", 6, 1, "map", chosen_mmu,
171 0x12, size, virt, virt);
172 return virt;
173 }
174
175 void *of_vmlinux_alloc(unsigned long size)
176 {
177 unsigned long start = (unsigned long)_start, end = (unsigned long)_end;
178 unsigned long addr;
179 void *p;
180
181 /* With some older POWER4 firmware we need to claim the area the kernel
182 * will reside in. Newer firmwares don't need this so we just ignore
183 * the return value.
184 */
185 addr = (unsigned long) of_claim(start, end - start, 0);
186 printf("Trying to claim from 0x%lx to 0x%lx (0x%lx) got %lx\r\n",
187 start, end, end - start, addr);
188
189 p = malloc(size);
190 if (!p)
191 fatal("Can't allocate memory for kernel image!\n\r");
192
193 return p;
194 }
195
196 void of_exit(void)
197 {
198 of_call_prom("exit", 0, 0);
199 }
200
201 /*
202 * OF device tree routines
203 */
204 void *of_finddevice(const char *name)
205 {
206 return (void *) (unsigned long) of_call_prom("finddevice", 1, 1, name);
207 }
208
209 int of_getprop(const void *phandle, const char *name, void *buf,
210 const int buflen)
211 {
212 return of_call_prom("getprop", 4, 1, phandle, name, buf, buflen);
213 }
214
215 int of_setprop(const void *phandle, const char *name, const void *buf,
216 const int buflen)
217 {
218 return of_call_prom("setprop", 4, 1, phandle, name, buf, buflen);
219 }
220
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