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 locoffs;
  61         unsigned long int value;
  62 #if __GNUC__ < 4
  63         unsigned long int old_value;
  64 #endif
  65
  66         pr_debug("Applying add relocation section %u to %u\n",
  67                 relsec, sechdrs[relsec].sh_info);
  68
  69         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
  70
  71                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
  72                                 rela[i].r_offset;
  73                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
  74                         ELF32_R_SYM(rela[i].r_info);
  75                 value = sym->st_value + rela[i].r_addend;
  76
  77                 switch (ELF32_R_TYPE(rela[i].r_info)) {
  78
  79                 /*
  80                  * Be careful! mb-gcc / mb-ld splits the relocs between the
  81                  * text and the reloc table. In general this means we must
  82                  * read the current contents of (*location), add any offset
  83                  * then store the result back in
  84                  */
  85
  86                 case R_MICROBLAZE_32:
  87 #if __GNUC__ < 4
  88                         old_value = *location;
  89                         *location = value + old_value;
  90
  91                         pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n",
  92                                 old_value, value);
  93 #else
  94                         *location = value;
  95 #endif
  96                         break;
  97
  98                 case R_MICROBLAZE_64:
  99 #if __GNUC__ < 4
 100                         /* Split relocs only required/used pre gcc4.1.1 */
 101                         old_value = ((location[0] & 0x0000FFFF) << 16) |
 102                                         (location[1] & 0x0000FFFF);
 103                         value += old_value;
 104 #endif
 105                         location[0] = (location[0] & 0xFFFF0000) |
 106                                         (value >> 16);
 107                         location[1] = (location[1] & 0xFFFF0000) |
 108                                         (value & 0xFFFF);
 109 #if __GNUC__ < 4
 110                         pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n",
 111                                 old_value, value);
 112 #endif
 113                         break;
 114
 115                 case R_MICROBLAZE_64_PCREL:
 116                         locoffs = (location[0] & 0xFFFF) << 16 |
 117                                 (location[1] & 0xFFFF);
 118                         value -= (unsigned long int)(location) + 4 +
 119                                 locoffs;
 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_NONE:
 129                         pr_debug("R_MICROBLAZE_NONE\n");
 130                         break;
 131
 132                 default:
 133                         printk(KERN_ERR "module %s: "
 134                                 "Unknown relocation: %u\n",
 135                                 module->name,
 136                                 ELF32_R_TYPE(rela->r_info));
 137                         return -ENOEXEC;
 138                 }
 139         }
 140         return 0;
 141 }
 142
 143 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
 144                 struct module *module)
 145 {
 146         return 0;
 147 }
 148
 149 void module_arch_cleanup(struct module *mod)
 150 {
 151 }