arch/powerpc/boot/oflib.c

   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 typedef u32 prom_arg_t;
  20
  21 /* The following structure is used to communicate with open firmware.
  22  * All arguments in and out are in big endian format. */
  23 struct prom_args {
  24         __be32 service; /* Address of service name string. */
  25         __be32 nargs;   /* Number of input arguments. */
  26         __be32 nret;    /* Number of output arguments. */
  27         __be32 args[10];        /* Input/output arguments. */
  28 };
  29
  30 #ifdef __powerpc64__
  31 extern int prom(void *);
  32 #else
  33 static int (*prom) (void *);
  34 #endif
  35
  36 void of_init(void *promptr)
  37 {
  38 #ifndef __powerpc64__
  39         prom = (int (*)(void *))promptr;
  40 #endif
  41 }
  42
  43 #define ADDR(x)         (u32)(unsigned long)(x)
  44
  45 int of_call_prom(const char *service, int nargs, int nret, ...)
  46 {
  47         int i;
  48         struct prom_args args;
  49         va_list list;
  50
  51         args.service = cpu_to_be32(ADDR(service));
  52         args.nargs = cpu_to_be32(nargs);
  53         args.nret = cpu_to_be32(nret);
  54
  55         va_start(list, nret);
  56         for (i = 0; i < nargs; i++)
  57                 args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
  58         va_end(list);
  59
  60         for (i = 0; i < nret; i++)
  61                 args.args[nargs+i] = 0;
  62
  63         if (prom(&args) < 0)
  64                 return PROM_ERROR;
  65
  66         return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
  67 }
  68
  69 static int of_call_prom_ret(const char *service, int nargs, int nret,
  70                             prom_arg_t *rets, ...)
  71 {
  72         int i;
  73         struct prom_args args;
  74         va_list list;
  75
  76         args.service = cpu_to_be32(ADDR(service));
  77         args.nargs = cpu_to_be32(nargs);
  78         args.nret = cpu_to_be32(nret);
  79
  80         va_start(list, rets);
  81         for (i = 0; i < nargs; i++)
  82                 args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
  83         va_end(list);
  84
  85         for (i = 0; i < nret; i++)
  86                 args.args[nargs+i] = 0;
  87
  88         if (prom(&args) < 0)
  89                 return PROM_ERROR;
  90
  91         if (rets != NULL)
  92                 for (i = 1; i < nret; ++i)
  93                         rets[i-1] = be32_to_cpu(args.args[nargs+i]);
  94
  95         return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
  96 }
  97
  98 /* returns true if s2 is a prefix of s1 */
  99 static int string_match(const char *s1, const char *s2)
 100 {
 101         for (; *s2; ++s2)
 102                 if (*s1++ != *s2)
 103                         return 0;
 104         return 1;
 105 }
 106
 107 /*
 108  * Older OF's require that when claiming a specific range of addresses,
 109  * we claim the physical space in the /memory node and the virtual
 110  * space in the chosen mmu node, and then do a map operation to
 111  * map virtual to physical.
 112  */
 113 static int need_map = -1;
 114 static ihandle chosen_mmu;
 115 static ihandle memory;
 116
 117 static int check_of_version(void)
 118 {
 119         phandle oprom, chosen;
 120         char version[64];
 121
 122         oprom = of_finddevice("/openprom");
 123         if (oprom == (phandle) -1)
 124                 return 0;
 125         if (of_getprop(oprom, "model", version, sizeof(version)) <= 0)
 126                 return 0;
 127         version[sizeof(version)-1] = 0;
 128         printf("OF version = '%s'\r\n", version);
 129         if (!string_match(version, "Open Firmware, 1.")
 130             && !string_match(version, "FirmWorks,3."))
 131                 return 0;
 132         chosen = of_finddevice("/chosen");
 133         if (chosen == (phandle) -1) {
 134                 chosen = of_finddevice("/chosen@0");
 135                 if (chosen == (phandle) -1) {
 136                         printf("no chosen\n");
 137                         return 0;
 138                 }
 139         }
 140         if (of_getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
 141                 printf("no mmu\n");
 142                 return 0;
 143         }
 144         memory = of_call_prom("open", 1, 1, "/memory");
 145         if (memory == PROM_ERROR) {
 146                 memory = of_call_prom("open", 1, 1, "/memory@0");
 147                 if (memory == PROM_ERROR) {
 148                         printf("no memory node\n");
 149                         return 0;
 150                 }
 151         }
 152         printf("old OF detected\r\n");
 153         return 1;
 154 }
 155
 156 unsigned int of_claim(unsigned long virt, unsigned long size,
 157                       unsigned long align)
 158 {
 159         int ret;
 160         prom_arg_t result;
 161
 162         if (need_map < 0)
 163                 need_map = check_of_version();
 164         if (align || !need_map)
 165                 return of_call_prom("claim", 3, 1, virt, size, align);
 166
 167         ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", memory,
 168                                align, size, virt);
 169         if (ret != 0 || result == -1)
 170                 return  -1;
 171         ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
 172                                align, size, virt);
 173         /* 0x12 == coherent + read/write */
 174         ret = of_call_prom("call-method", 6, 1, "map", chosen_mmu,
 175                            0x12, size, virt, virt);
 176         return virt;
 177 }
 178
 179 void *of_vmlinux_alloc(unsigned long size)
 180 {
 181         unsigned long start = (unsigned long)_start, end = (unsigned long)_end;
 182         unsigned long addr;
 183         void *p;
 184
 185         /* With some older POWER4 firmware we need to claim the area the kernel
 186          * will reside in.  Newer firmwares don't need this so we just ignore
 187          * the return value.
 188          */
 189         addr = (unsigned long) of_claim(start, end - start, 0);
 190         printf("Trying to claim from 0x%lx to 0x%lx (0x%lx) got %lx\r\n",
 191                start, end, end - start, addr);
 192
 193         p = malloc(size);
 194         if (!p)
 195                 fatal("Can't allocate memory for kernel image!\n\r");
 196
 197         return p;
 198 }
 199
 200 void of_exit(void)
 201 {
 202         of_call_prom("exit", 0, 0);
 203 }
 204
 205 /*
 206  * OF device tree routines
 207  */
 208 void *of_finddevice(const char *name)
 209 {
 210         return (void *) (unsigned long) of_call_prom("finddevice", 1, 1, name);
 211 }
 212
 213 int of_getprop(const void *phandle, const char *name, void *buf,
 214                const int buflen)
 215 {
 216         return of_call_prom("getprop", 4, 1, phandle, name, buf, buflen);
 217 }
 218
 219 int of_setprop(const void *phandle, const char *name, const void *buf,
 220                const int buflen)
 221 {
 222         return of_call_prom("setprop", 4, 1, phandle, name, buf, buflen);
 223 }