arch/microblaze/kernel/module.c

   1 /*
   2  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2007-2009 PetaLogix
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/moduleloader.h>
  12 #include <linux/kernel.h>
  13 #include <linux/elf.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/fs.h>
  16 #include <linux/string.h>
  17
  18 #include <asm/pgtable.h>
  19 #include <asm/cacheflush.h>
  20
  21 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
  22         unsigned int symindex, unsigned int relsec, struct module *module)
  23 {
  24
  25         unsigned int i;
  26         Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
  27         Elf32_Sym *sym;
  28         unsigned long int *location;
  29         unsigned long int value;
  30 #if __GNUC__ < 4
  31         unsigned long int old_value;
  32 #endif
  33
  34         pr_debug("Applying add relocation section %u to %u\n",
  35                 relsec, sechdrs[relsec].sh_info);
  36
  37         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
  38
  39                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
  40                                 rela[i].r_offset;
  41                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
  42                         ELF32_R_SYM(rela[i].r_info);
  43                 value = sym->st_value + rela[i].r_addend;
  44
  45                 switch (ELF32_R_TYPE(rela[i].r_info)) {
  46
  47                 /*
  48                  * Be careful! mb-gcc / mb-ld splits the relocs between the
  49                  * text and the reloc table. In general this means we must
  50                  * read the current contents of (*location), add any offset
  51                  * then store the result back in
  52                  */
  53
  54                 case R_MICROBLAZE_32:
  55 #if __GNUC__ < 4
  56                         old_value = *location;
  57                         *location = value + old_value;
  58
  59                         pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n",
  60                                 old_value, value);
  61 #else
  62                         *location = value;
  63 #endif
  64                         break;
  65
  66                 case R_MICROBLAZE_64:
  67 #if __GNUC__ < 4
  68                         /* Split relocs only required/used pre gcc4.1.1 */
  69                         old_value = ((location[0] & 0x0000FFFF) << 16) |
  70                                         (location[1] & 0x0000FFFF);
  71                         value += old_value;
  72 #endif
  73                         location[0] = (location[0] & 0xFFFF0000) |
  74                                         (value >> 16);
  75                         location[1] = (location[1] & 0xFFFF0000) |
  76                                         (value & 0xFFFF);
  77 #if __GNUC__ < 4
  78                         pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n",
  79                                 old_value, value);
  80 #endif
  81                         break;
  82
  83                 case R_MICROBLAZE_64_PCREL:
  84 #if __GNUC__ < 4
  85                         old_value = (location[0] & 0xFFFF) << 16 |
  86                                 (location[1] & 0xFFFF);
  87                         value -= old_value;
  88 #endif
  89                         value -= (unsigned long int)(location) + 4;
  90                         location[0] = (location[0] & 0xFFFF0000) |
  91                                         (value >> 16);
  92                         location[1] = (location[1] & 0xFFFF0000) |
  93                                         (value & 0xFFFF);
  94                         pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
  95                                 value);
  96                         break;
  97
  98                 case R_MICROBLAZE_32_PCREL_LO:
  99                         pr_debug("R_MICROBLAZE_32_PCREL_LO\n");
 100                         break;
 101
 102                 case R_MICROBLAZE_64_NONE:
 103                         pr_debug("R_MICROBLAZE_64_NONE\n");
 104                         break;
 105
 106                 case R_MICROBLAZE_NONE:
 107                         pr_debug("R_MICROBLAZE_NONE\n");
 108                         break;
 109
 110                 default:
 111                         printk(KERN_ERR "module %s: "
 112                                 "Unknown relocation: %u\n",
 113                                 module->name,
 114                                 ELF32_R_TYPE(rela[i].r_info));
 115                         return -ENOEXEC;
 116                 }
 117         }
 118         return 0;
 119 }
 120
 121 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
 122                 struct module *module)
 123 {
 124         flush_dcache();
 125         return 0;
 126 }