arch/powerpc/boot/prom.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 <stdarg.h>
  10 #include <stddef.h>
  11 #include "string.h"
  12 #include "stdio.h"
  13 #include "prom.h"
  14
  15 int (*prom)(void *);
  16 phandle chosen_handle;
  17 ihandle stdout;
  18
  19 int 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
  48 int 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
  82 int 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  */
  93 static int need_map = -1;
  94 static ihandle chosen_mmu;
  95 static phandle memory;
  96
  97 /* returns true if s2 is a prefix of s1 */
  98 static 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
 106 static 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
 145 void *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 }