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
  20 void *module_alloc(unsigned long size)
  21 {
  22         void *ret;
  23         ret = (size == 0) ? NULL : vmalloc(size);
  24         pr_debug("module_alloc (%08lx@%08lx)\n", size, (unsigned long int)ret);
  25         return ret;
  26 }
  27
  28 void module_free(struct module *module, void *region)
  29 {
  30         pr_debug("module_free(%s,%08lx)\n", module->name,
  31                                         (unsigned long)region);
  32         vfree(region);
  33 }
  34
  35 int module_frob_arch_sections(Elf_Ehdr *hdr,
  36                                 Elf_Shdr *sechdrs,
  37                                 char *secstrings,
  38                                 struct module *mod)
  39 {
  40         return 0;
  41 }
  42
  43 int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab,
  44         unsigned int symindex, unsigned int relsec, struct module *module)
  45 {
  46         printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
  47                 module->name);
  48         return -ENOEXEC;
  49 }
  50
  51 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
  52         unsigned int symindex, unsigned int relsec, struct module *module)
  53 {
  54
  55         unsigned int i;
  56         Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
  57         Elf32_Sym *sym;
  58         unsigned long int *location;
  59         unsigned long int value;
  60 #if __GNUC__ < 4
  61         unsigned long int old_value;
  62 #endif
  63
  64         pr_debug("Applying add relocation section %u to %u\n",
  65                 relsec, sechdrs[relsec].sh_info);
  66
  67         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
  68
  69                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
  70                                 rela[i].r_offset;
  71                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
  72                         ELF32_R_SYM(rela[i].r_info);
  73                 value = sym->st_value + rela[i].r_addend;
  74
  75                 switch (ELF32_R_TYPE(rela[i].r_info)) {
  76
  77                 /*
  78                  * Be careful! mb-gcc / mb-ld splits the relocs between the
  79                  * text and the reloc table. In general this means we must
  80                  * read the current contents of (*location), add any offset
  81                  * then store the result back in
  82                  */
  83
  84                 case R_MICROBLAZE_32:
  85 #if __GNUC__ < 4
  86                         old_value = *location;
  87                         *location = value + old_value;
  88
  89                         pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n",
  90                                 old_value, value);
  91 #else
  92                         *location = value;
  93 #endif
  94                         break;
  95
  96                 case R_MICROBLAZE_64:
  97 #if __GNUC__ < 4
  98                         /* Split relocs only required/used pre gcc4.1.1 */
  99                         old_value = ((location[0] & 0x0000FFFF) << 16) |
 100                                         (location[1] & 0x0000FFFF);
 101                         value += old_value;
 102 #endif
 103                         location[0] = (location[0] & 0xFFFF0000) |
 104                                         (value >> 16);
 105                         location[1] = (location[1] & 0xFFFF0000) |
 106                                         (value & 0xFFFF);
 107 #if __GNUC__ < 4
 108                         pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n",
 109                                 old_value, value);
 110 #endif
 111                         break;
 112
 113                 case R_MICROBLAZE_64_PCREL:
 114 #if __GNUC__ < 4
 115                         old_value = (location[0] & 0xFFFF) << 16 |
 116                                 (location[1] & 0xFFFF);
 117                         value -= old_value;
 118 #endif
 119                         value -= (unsigned long int)(location) + 4;
 120                         location[0] = (location[0] & 0xFFFF0000) |
 121                                         (value >> 16);
 122                         location[1] = (location[1] & 0xFFFF0000) |
 123                                         (value & 0xFFFF);
 124                         pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
 125                                 value);
 126                         break;
 127
 128                 case R_MICROBLAZE_32_PCREL_LO:
 129                         pr_debug("R_MICROBLAZE_32_PCREL_LO\n");
 130                         break;
 131
 132                 case R_MICROBLAZE_64_NONE:
 133                         pr_debug("R_MICROBLAZE_NONE\n");
 134                         break;
 135
 136                 case R_MICROBLAZE_NONE:
 137                         pr_debug("R_MICROBLAZE_NONE\n");
 138                         break;
 139
 140                 default:
 141                         printk(KERN_ERR "module %s: "
 142                                 "Unknown relocation: %u\n",
 143                                 module->name,
 144                                 ELF32_R_TYPE(rela[i].r_info));
 145                         return -ENOEXEC;
 146                 }
 147         }
 148         return 0;
 149 }
 150
 151 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
 152                 struct module *module)
 153 {
 154         return 0;
 155 }
 156
 157 void module_arch_cleanup(struct module *mod)
 158 {
 159 }