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/slab.h>
  16 #include <linux/fs.h>
  17 #include <linux/string.h>
  18
  19 #include <asm/pgtable.h>
  20
  21 void *module_alloc(unsigned long size)
  22 {
  23         void *ret;
  24         ret = (size == 0) ? NULL : vmalloc(size);
  25         pr_debug("module_alloc (%08lx@%08lx)\n", size, (unsigned long int)ret);
  26         return ret;
  27 }
  28
  29 void module_free(struct module *module, void *region)
  30 {
  31         pr_debug("module_free(%s,%08lx)\n", module->name,
  32                                         (unsigned long)region);
  33         vfree(region);
  34 }
  35
  36 int module_frob_arch_sections(Elf_Ehdr *hdr,
  37                                 Elf_Shdr *sechdrs,
  38                                 char *secstrings,
  39                                 struct module *mod)
  40 {
  41         return 0;
  42 }
  43
  44 int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab,
  45         unsigned int symindex, unsigned int relsec, struct module *module)
  46 {
  47         printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
  48                 module->name);
  49         return -ENOEXEC;
  50 }
  51
  52 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
  53         unsigned int symindex, unsigned int relsec, struct module *module)
  54 {
  55
  56         unsigned int i;
  57         Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
  58         Elf32_Sym *sym;
  59         unsigned long int *location;
  60         unsigned long int value;
  61 #if __GNUC__ < 4
  62         unsigned long int old_value;
  63 #endif
  64
  65         pr_debug("Applying add relocation section %u to %u\n",
  66                 relsec, sechdrs[relsec].sh_info);
  67
  68         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
  69
  70                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
  71                                 rela[i].r_offset;
  72                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
  73                         ELF32_R_SYM(rela[i].r_info);
  74                 value = sym->st_value + rela[i].r_addend;
  75
  76                 switch (ELF32_R_TYPE(rela[i].r_info)) {
  77
  78                 /*
  79                  * Be careful! mb-gcc / mb-ld splits the relocs between the
  80                  * text and the reloc table. In general this means we must
  81                  * read the current contents of (*location), add any offset
  82                  * then store the result back in
  83                  */
  84
  85                 case R_MICROBLAZE_32:
  86 #if __GNUC__ < 4
  87                         old_value = *location;
  88                         *location = value + old_value;
  89
  90                         pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n",
  91                                 old_value, value);
  92 #else
  93                         *location = value;
  94 #endif
  95                         break;
  96
  97                 case R_MICROBLAZE_64:
  98 #if __GNUC__ < 4
  99                         /* Split relocs only required/used pre gcc4.1.1 */
 100                         old_value = ((location[0] & 0x0000FFFF) << 16) |
 101                                         (location[1] & 0x0000FFFF);
 102                         value += old_value;
 103 #endif
 104                         location[0] = (location[0] & 0xFFFF0000) |
 105                                         (value >> 16);
 106                         location[1] = (location[1] & 0xFFFF0000) |
 107                                         (value & 0xFFFF);
 108 #if __GNUC__ < 4
 109                         pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n",
 110                                 old_value, value);
 111 #endif
 112                         break;
 113
 114                 case R_MICROBLAZE_64_PCREL:
 115 #if __GNUC__ < 4
 116                         old_value = (location[0] & 0xFFFF) << 16 |
 117                                 (location[1] & 0xFFFF);
 118                         value -= old_value;
 119 #endif
 120                         value -= (unsigned long int)(location) + 4;
 121                         location[0] = (location[0] & 0xFFFF0000) |
 122                                         (value >> 16);
 123                         location[1] = (location[1] & 0xFFFF0000) |
 124                                         (value & 0xFFFF);
 125                         pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
 126                                 value);
 127                         break;
 128
 129                 case R_MICROBLAZE_32_PCREL_LO:
 130                         pr_debug("R_MICROBLAZE_32_PCREL_LO\n");
 131                         break;
 132
 133                 case R_MICROBLAZE_64_NONE:
 134                         pr_debug("R_MICROBLAZE_NONE\n");
 135                         break;
 136
 137                 case R_MICROBLAZE_NONE:
 138                         pr_debug("R_MICROBLAZE_NONE\n");
 139                         break;
 140
 141                 default:
 142                         printk(KERN_ERR "module %s: "
 143                                 "Unknown relocation: %u\n",
 144                                 module->name,
 145                                 ELF32_R_TYPE(rela[i].r_info));
 146                         return -ENOEXEC;
 147                 }
 148         }
 149         return 0;
 150 }
 151
 152 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
 153                 struct module *module)
 154 {
 155         return 0;
 156 }
 157
 158 void module_arch_cleanup(struct module *mod)
 159 {
 160 }