root/arch/powerpc/boot/oflib.c

DEFINITIONS

1. of_init
2. of_call_prom
3. of_call_prom_ret
4. string_match
5. check_of_version
6. of_claim
7. of_vmlinux_alloc
8. of_exit
9. of_finddevice
10. of_getprop
11. of_setprop

   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 }