arch/blackfin/kernel/module.c

   1 /*
   2  * File:         arch/blackfin/kernel/module.c
   3  * Based on:
   4  * Author:
   5  *
   6  * Created:
   7  * Description:
   8  *
   9  * Modified:
  10  *               Copyright 2004-2006 Analog Devices Inc.
  11  *
  12  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, see the file COPYING, or write
  26  * to the Free Software Foundation, Inc.,
  27  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  28  */
  29
  30
  31 #include <linux/moduleloader.h>
  32 #include <linux/elf.h>
  33 #include <linux/vmalloc.h>
  34 #include <linux/fs.h>
  35 #include <linux/string.h>
  36 #include <linux/kernel.h>
  37 #include <asm/dma.h>
  38 #include <asm/cacheflush.h>
  39
  40 /*
  41  * handle arithmetic relocations.
  42  * See binutils/bfd/elf32-bfin.c for more details
  43  */
  44 #define RELOC_STACK_SIZE 100
  45 static uint32_t reloc_stack[RELOC_STACK_SIZE];
  46 static unsigned int reloc_stack_tos;
  47
  48 #define is_reloc_stack_empty() ((reloc_stack_tos > 0)?0:1)
  49
  50 static void reloc_stack_push(uint32_t value)
  51 {
  52         reloc_stack[reloc_stack_tos++] = value;
  53 }
  54
  55 static uint32_t reloc_stack_pop(void)
  56 {
  57         return reloc_stack[--reloc_stack_tos];
  58 }
  59
  60 static uint32_t reloc_stack_operate(unsigned int oper, struct module *mod)
  61 {
  62         uint32_t value;
  63
  64         switch (oper) {
  65         case R_add:
  66                 value = reloc_stack[reloc_stack_tos - 2] +
  67                         reloc_stack[reloc_stack_tos - 1];
  68                 reloc_stack_tos -= 2;
  69                 break;
  70         case R_sub:
  71                 value = reloc_stack[reloc_stack_tos - 2] -
  72                         reloc_stack[reloc_stack_tos - 1];
  73                 reloc_stack_tos -= 2;
  74                 break;
  75         case R_mult:
  76                 value = reloc_stack[reloc_stack_tos - 2] *
  77                         reloc_stack[reloc_stack_tos - 1];
  78                 reloc_stack_tos -= 2;
  79                 break;
  80         case R_div:
  81                 value = reloc_stack[reloc_stack_tos - 2] /
  82                         reloc_stack[reloc_stack_tos - 1];
  83                 reloc_stack_tos -= 2;
  84                 break;
  85         case R_mod:
  86                 value = reloc_stack[reloc_stack_tos - 2] %
  87                         reloc_stack[reloc_stack_tos - 1];
  88                 reloc_stack_tos -= 2;
  89                 break;
  90         case R_lshift:
  91                 value = reloc_stack[reloc_stack_tos - 2] <<
  92                         reloc_stack[reloc_stack_tos - 1];
  93                 reloc_stack_tos -= 2;
  94                 break;
  95         case R_rshift:
  96                 value = reloc_stack[reloc_stack_tos - 2] >>
  97                         reloc_stack[reloc_stack_tos - 1];
  98                 reloc_stack_tos -= 2;
  99                 break;
 100         case R_and:
 101                 value = reloc_stack[reloc_stack_tos - 2] &
 102                         reloc_stack[reloc_stack_tos - 1];
 103                 reloc_stack_tos -= 2;
 104                 break;
 105         case R_or:
 106                 value = reloc_stack[reloc_stack_tos - 2] |
 107                         reloc_stack[reloc_stack_tos - 1];
 108                 reloc_stack_tos -= 2;
 109                 break;
 110         case R_xor:
 111                 value = reloc_stack[reloc_stack_tos - 2] ^
 112                         reloc_stack[reloc_stack_tos - 1];
 113                 reloc_stack_tos -= 2;
 114                 break;
 115         case R_land:
 116                 value = reloc_stack[reloc_stack_tos - 2] &&
 117                         reloc_stack[reloc_stack_tos - 1];
 118                 reloc_stack_tos -= 2;
 119                 break;
 120         case R_lor:
 121                 value = reloc_stack[reloc_stack_tos - 2] ||
 122                         reloc_stack[reloc_stack_tos - 1];
 123                 reloc_stack_tos -= 2;
 124                 break;
 125         case R_neg:
 126                 value = -reloc_stack[reloc_stack_tos - 1];
 127                 reloc_stack_tos--;
 128                 break;
 129         case R_comp:
 130                 value = ~reloc_stack[reloc_stack_tos - 1];
 131                 reloc_stack_tos -= 1;
 132                 break;
 133         default:
 134                 printk(KERN_WARNING "module %s: unhandled reloction\n",
 135                                 mod->name);
 136                 return 0;
 137         }
 138
 139         /* now push the new value back on stack */
 140         reloc_stack_push(value);
 141
 142         return value;
 143 }
 144
 145 void *module_alloc(unsigned long size)
 146 {
 147         if (size == 0)
 148                 return NULL;
 149         return vmalloc(size);
 150 }
 151
 152 /* Free memory returned from module_alloc */
 153 void module_free(struct module *mod, void *module_region)
 154 {
 155         vfree(module_region);
 156 }
 157
 158 /* Transfer the section to the L1 memory */
 159 int
 160 module_frob_arch_sections(Elf_Ehdr * hdr, Elf_Shdr * sechdrs,
 161                           char *secstrings, struct module *mod)
 162 {
 163         Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
 164         void *dest = NULL;
 165
 166         for (s = sechdrs; s < sechdrs_end; ++s) {
 167                 if ((strcmp(".l1.text", secstrings + s->sh_name) == 0) ||
 168                     ((strcmp(".text", secstrings + s->sh_name) == 0) &&
 169                      (hdr->e_flags & FLG_CODE_IN_L1) && (s->sh_size > 0))) {
 170                         mod->arch.text_l1 = s;
 171                         dest = l1_inst_sram_alloc(s->sh_size);
 172                         if (dest == NULL) {
 173                                 printk(KERN_ERR
 174                                        "module %s: L1 instruction memory allocation failed\n",
 175                                        mod->name);
 176                                 return -1;
 177                         }
 178                         dma_memcpy(dest, (void *)s->sh_addr, s->sh_size);
 179                         s->sh_flags &= ~SHF_ALLOC;
 180                         s->sh_addr = (unsigned long)dest;
 181                 }
 182                 if ((strcmp(".l1.data", secstrings + s->sh_name) == 0) ||
 183                     ((strcmp(".data", secstrings + s->sh_name) == 0) &&
 184                      (hdr->e_flags & FLG_DATA_IN_L1) && (s->sh_size > 0))) {
 185                         mod->arch.data_a_l1 = s;
 186                         dest = l1_data_sram_alloc(s->sh_size);
 187                         if (dest == NULL) {
 188                                 printk(KERN_ERR
 189                                         "module %s: L1 data memory allocation failed\n",
 190                                         mod->name);
 191                                 return -1;
 192                         }
 193                         memcpy(dest, (void *)s->sh_addr, s->sh_size);
 194                         s->sh_flags &= ~SHF_ALLOC;
 195                         s->sh_addr = (unsigned long)dest;
 196                 }
 197                 if (strcmp(".l1.bss", secstrings + s->sh_name) == 0 ||
 198                     ((strcmp(".bss", secstrings + s->sh_name) == 0) &&
 199                      (hdr->e_flags & FLG_DATA_IN_L1) && (s->sh_size > 0))) {
 200                         mod->arch.bss_a_l1 = s;
 201                         dest = l1_data_sram_alloc(s->sh_size);
 202                         if (dest == NULL) {
 203                                 printk(KERN_ERR
 204                                         "module %s: L1 data memory allocation failed\n",
 205                                         mod->name);
 206                                 return -1;
 207                         }
 208                         memset(dest, 0, s->sh_size);
 209                         s->sh_flags &= ~SHF_ALLOC;
 210                         s->sh_addr = (unsigned long)dest;
 211                 }
 212                 if (strcmp(".l1.data.B", secstrings + s->sh_name) == 0) {
 213                         mod->arch.data_b_l1 = s;
 214                         dest = l1_data_B_sram_alloc(s->sh_size);
 215                         if (dest == NULL) {
 216                                 printk(KERN_ERR
 217                                         "module %s: L1 data memory allocation failed\n",
 218                                         mod->name);
 219                                 return -1;
 220                         }
 221                         memcpy(dest, (void *)s->sh_addr, s->sh_size);
 222                         s->sh_flags &= ~SHF_ALLOC;
 223                         s->sh_addr = (unsigned long)dest;
 224                 }
 225                 if (strcmp(".l1.bss.B", secstrings + s->sh_name) == 0) {
 226                         mod->arch.bss_b_l1 = s;
 227                         dest = l1_data_B_sram_alloc(s->sh_size);
 228                         if (dest == NULL) {
 229                                 printk(KERN_ERR
 230                                         "module %s: L1 data memory allocation failed\n",
 231                                         mod->name);
 232                                 return -1;
 233                         }
 234                         memset(dest, 0, s->sh_size);
 235                         s->sh_flags &= ~SHF_ALLOC;
 236                         s->sh_addr = (unsigned long)dest;
 237                 }
 238         }
 239         return 0;
 240 }
 241
 242 int
 243 apply_relocate(Elf_Shdr * sechdrs, const char *strtab,
 244                unsigned int symindex, unsigned int relsec, struct module *me)
 245 {
 246         printk(KERN_ERR "module %s: .rel unsupported\n", me->name);
 247         return -ENOEXEC;
 248 }
 249
 250 /*************************************************************************/
 251 /* FUNCTION : apply_relocate_add                                         */
 252 /* ABSTRACT : Blackfin specific relocation handling for the loadable     */
 253 /*            modules. Modules are expected to be .o files.              */
 254 /*            Arithmetic relocations are handled.                        */
 255 /*            We do not expect LSETUP to be split and hence is not       */
 256 /*            handled.                                                   */
 257 /*            R_byte and R_byte2 are also not handled as the gas         */
 258 /*            does not generate it.                                      */
 259 /*************************************************************************/
 260 int
 261 apply_relocate_add(Elf_Shdr * sechdrs, const char *strtab,
 262                    unsigned int symindex, unsigned int relsec,
 263                    struct module *mod)
 264 {
 265         unsigned int i;
 266         unsigned short tmp;
 267         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
 268         Elf32_Sym *sym;
 269         uint32_t *location32;
 270         uint16_t *location16;
 271         uint32_t value;
 272
 273         pr_debug("Applying relocate section %u to %u\n", relsec,
 274                sechdrs[relsec].sh_info);
 275         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 276                 /* This is where to make the change */
 277                 location16 =
 278                     (uint16_t *) (sechdrs[sechdrs[relsec].sh_info].sh_addr +
 279                                   rel[i].r_offset);
 280                 location32 = (uint32_t *) location16;
 281                 /* This is the symbol it is referring to. Note that all
 282                    undefined symbols have been resolved. */
 283                 sym = (Elf32_Sym *) sechdrs[symindex].sh_addr
 284                     + ELF32_R_SYM(rel[i].r_info);
 285                 if (is_reloc_stack_empty()) {
 286                         value = sym->st_value;
 287                 } else {
 288                         value = reloc_stack_pop();
 289                 }
 290                 value += rel[i].r_addend;
 291                 pr_debug("location is %x, value is %x type is %d \n",
 292                          (unsigned int) location32, value,
 293                          ELF32_R_TYPE(rel[i].r_info));
 294
 295                 switch (ELF32_R_TYPE(rel[i].r_info)) {
 296
 297                 case R_pcrel24:
 298                 case R_pcrel24_jump_l:
 299                         /* Add the value, subtract its postition */
 300                         location16 =
 301                             (uint16_t *) (sechdrs[sechdrs[relsec].sh_info].
 302                                           sh_addr + rel[i].r_offset - 2);
 303                         location32 = (uint32_t *) location16;
 304                         value -= (uint32_t) location32;
 305                         value >>= 1;
 306                         pr_debug("value is %x, before %x-%x after %x-%x\n", value,
 307                                *location16, *(location16 + 1),
 308                                (*location16 & 0xff00) | (value >> 16 & 0x00ff),
 309                                value & 0xffff);
 310                         *location16 =
 311                             (*location16 & 0xff00) | (value >> 16 & 0x00ff);
 312                         *(location16 + 1) = value & 0xffff;
 313                         break;
 314                 case R_pcrel12_jump:
 315                 case R_pcrel12_jump_s:
 316                         value -= (uint32_t) location32;
 317                         value >>= 1;
 318                         *location16 = (value & 0xfff);
 319                         break;
 320                 case R_pcrel10:
 321                         value -= (uint32_t) location32;
 322                         value >>= 1;
 323                         *location16 = (value & 0x3ff);
 324                         break;
 325                 case R_luimm16:
 326                         pr_debug("before %x after %x\n", *location16,
 327                                        (value & 0xffff));
 328                         tmp = (value & 0xffff);
 329                         if ((unsigned long)location16 >= L1_CODE_START) {
 330                                 dma_memcpy(location16, &tmp, 2);
 331                         } else
 332                                 *location16 = tmp;
 333                         break;
 334                 case R_huimm16:
 335                         pr_debug("before %x after %x\n", *location16,
 336                                        ((value >> 16) & 0xffff));
 337                         tmp = ((value >> 16) & 0xffff);
 338                         if ((unsigned long)location16 >= L1_CODE_START) {
 339                                 dma_memcpy(location16, &tmp, 2);
 340                         } else
 341                                 *location16 = tmp;
 342                         break;
 343                 case R_rimm16:
 344                         *location16 = (value & 0xffff);
 345                         break;
 346                 case R_byte4_data:
 347                         pr_debug("before %x after %x\n", *location32, value);
 348                         *location32 = value;
 349                         break;
 350                 case R_push:
 351                         reloc_stack_push(value);
 352                         break;
 353                 case R_const:
 354                         reloc_stack_push(rel[i].r_addend);
 355                         break;
 356                 case R_add:
 357                 case R_sub:
 358                 case R_mult:
 359                 case R_div:
 360                 case R_mod:
 361                 case R_lshift:
 362                 case R_rshift:
 363                 case R_and:
 364                 case R_or:
 365                 case R_xor:
 366                 case R_land:
 367                 case R_lor:
 368                 case R_neg:
 369                 case R_comp:
 370                         reloc_stack_operate(ELF32_R_TYPE(rel[i].r_info), mod);
 371                         break;
 372                 default:
 373                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 374                                mod->name, ELF32_R_TYPE(rel[i].r_info));
 375                         return -ENOEXEC;
 376                 }
 377         }
 378         return 0;
 379 }
 380
 381 int
 382 module_finalize(const Elf_Ehdr * hdr,
 383                 const Elf_Shdr * sechdrs, struct module *mod)
 384 {
 385         unsigned int i, strindex = 0, symindex = 0;
 386         char *secstrings;
 387
 388         secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 389
 390         for (i = 1; i < hdr->e_shnum; i++) {
 391                 /* Internal symbols and strings. */
 392                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
 393                         symindex = i;
 394                         strindex = sechdrs[i].sh_link;
 395                 }
 396         }
 397
 398         for (i = 1; i < hdr->e_shnum; i++) {
 399                 const char *strtab = (char *)sechdrs[strindex].sh_addr;
 400                 unsigned int info = sechdrs[i].sh_info;
 401
 402                 /* Not a valid relocation section? */
 403                 if (info >= hdr->e_shnum)
 404                         continue;
 405
 406                 if ((sechdrs[i].sh_type == SHT_RELA) &&
 407                     ((strcmp(".rela.l1.text", secstrings + sechdrs[i].sh_name) == 0) ||
 408                     ((strcmp(".rela.text", secstrings + sechdrs[i].sh_name) == 0) &&
 409                          (hdr->e_flags & FLG_CODE_IN_L1)))) {
 410                         apply_relocate_add((Elf_Shdr *) sechdrs, strtab,
 411                                            symindex, i, mod);
 412                 }
 413         }
 414         return 0;
 415 }
 416
 417 void module_arch_cleanup(struct module *mod)
 418 {
 419         if ((mod->arch.text_l1) && (mod->arch.text_l1->sh_addr))
 420                 l1_inst_sram_free((void *)mod->arch.text_l1->sh_addr);
 421         if ((mod->arch.data_a_l1) && (mod->arch.data_a_l1->sh_addr))
 422                 l1_data_sram_free((void *)mod->arch.data_a_l1->sh_addr);
 423         if ((mod->arch.bss_a_l1) && (mod->arch.bss_a_l1->sh_addr))
 424                 l1_data_sram_free((void *)mod->arch.bss_a_l1->sh_addr);
 425         if ((mod->arch.data_b_l1) && (mod->arch.data_b_l1->sh_addr))
 426                 l1_data_B_sram_free((void *)mod->arch.data_b_l1->sh_addr);
 427         if ((mod->arch.bss_b_l1) && (mod->arch.bss_b_l1->sh_addr))
 428                 l1_data_B_sram_free((void *)mod->arch.bss_b_l1->sh_addr);
 429 }