target/linux/ubicom32/files/arch/ubicom32/kernel/module.c

   1 /*
   2  * arch/ubicom32/kernel/module.c
   3  *   Ubicom32 architecture loadable module support.
   4  *
   5  * (C) Copyright 2009, Ubicom, Inc.
   6  *
   7  * This file is part of the Ubicom32 Linux Kernel Port.
   8  *
   9  * The Ubicom32 Linux Kernel Port is free software: you can redistribute
  10  * it and/or modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation, either version 2 of the
  12  * License, or (at your option) any later version.
  13  *
  14  * The Ubicom32 Linux Kernel Port is distributed in the hope that it
  15  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  16  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  * the GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with the Ubicom32 Linux Kernel Port.  If not,
  21  * see <http://www.gnu.org/licenses/>.
  22  *
  23  * Ubicom32 implementation derived from (with many thanks):
  24  *   arch/m68knommu
  25  *   arch/blackfin
  26  *   arch/parisc
  27  */
  28 #include <linux/moduleloader.h>
  29 #include <linux/bug.h>
  30 #include <linux/elf.h>
  31 #include <linux/vmalloc.h>
  32 #include <linux/fs.h>
  33 #include <linux/string.h>
  34 #include <linux/kernel.h>
  35 #include <asm/ocm-alloc.h>
  36
  37 #if 0
  38 #define DEBUGP printk
  39 #else
  40 #define DEBUGP(fmt...)
  41 #endif
  42
  43 static void _module_free_ocm(struct module *mod)
  44 {
  45         printk(KERN_INFO "module arch cleanup %s: OCM instruction memory free "
  46                " of %d @%p\n", mod->name, mod->arch.ocm_inst_size,
  47                mod->arch.ocm_inst);
  48
  49         if (mod->arch.ocm_inst) {
  50                 ocm_inst_free(mod->arch.ocm_inst);
  51                 mod->arch.ocm_inst = 0;
  52                 mod->arch.ocm_inst_size = 0;
  53         }
  54 }
  55
  56 void *module_alloc(unsigned long size)
  57 {
  58         if (size == 0)
  59                 return NULL;
  60         return vmalloc(size);
  61 }
  62
  63
  64 /* Free memory returned from module_alloc */
  65 void module_free(struct module *mod, void *module_region)
  66 {
  67         vfree(module_region);
  68         /* FIXME: If module_region == mod->init_region, trim exception
  69            table entries. */
  70
  71         /*
  72          * This is expected to be final module free, use this to prune the
  73          * ocm
  74          */
  75         if (module_region && module_region == mod->module_core)
  76                 _module_free_ocm(mod);
  77
  78 }
  79
  80 /*
  81  * module_frob_arch_sections()
  82  *      Called from kernel/module.c allowing arch specific handling of
  83  *      sections/headers.
  84  */
  85 int module_frob_arch_sections(Elf_Ehdr *hdr,
  86                               Elf_Shdr *sechdrs,
  87                               char *secstrings,
  88                               struct module *mod)
  89 {
  90         Elf_Shdr *s, *sechdrs_end;
  91         void *ocm_inst = NULL;
  92         int ocm_inst_size = 0;
  93
  94         /*
  95          * Ubicom32 v3 and v4 are almost binary compatible but not completely.
  96          * To be safe check that the module was compiled with the correct -march
  97          * which is flags.
  98          */
  99 #ifdef CONFIG_UBICOM32_V4
 100         if ((hdr->e_flags & 0xFFFF) != EF_UBICOM32_V4) {
 101                 printk(KERN_WARNING "Module %s was not compiled for "
 102                        "ubicom32v4, elf_flags:%x,\n",
 103                        mod->name, hdr->e_flags);
 104                 return -ENOEXEC;
 105         }
 106 #elif defined CONFIG_UBICOM32_V3
 107         if ((hdr->e_flags & 0xFFFF) != EF_UBICOM32_V3) {
 108                 printk(KERN_WARNING "Module %s was not compiled for "
 109                        "ubicom32v3, elf_flags:%x\n",
 110                        mod->name, hdr->e_flags);
 111                 return -ENOEXEC;
 112         }
 113 #else
 114 #error Unknown/Unsupported ubicom32 architecture.
 115 #endif
 116
 117         /*
 118          * XXX: sechdrs are vmalloced in kernel/module.c
 119          * and would be vfreed just after module is loaded,
 120          * so we hack to keep the only information we needed
 121          * in mod->arch to correctly free L1 I/D sram later.
 122          * NOTE: this breaks the semantic of mod->arch structure.
 123          */
 124         sechdrs_end = sechdrs + hdr->e_shnum;
 125         for (s = sechdrs; s < sechdrs_end; ++s) {
 126                 if (strncmp(".ocm_text", secstrings + s->sh_name, 9) == 0)
 127                         ocm_inst_size += s->sh_size;
 128         }
 129
 130         if (!ocm_inst_size)
 131                 return 0;
 132
 133         ocm_inst = ocm_inst_alloc(ocm_inst_size, 0 /* internal */);
 134         if (ocm_inst == NULL) {
 135 #ifdef CONFIG_OCM_MODULES_FALLBACK_TO_DDR
 136                 printk(KERN_WARNING
 137                        "module %s: OCM instruction memory allocation of %d"
 138                        "failed, fallback to DDR\n", mod->name, ocm_inst_size);
 139                 return 0;
 140 #else
 141                 printk(KERN_ERR
 142                        "module %s: OCM instruction memory allocation of %d"
 143                        "failed.\n", mod->name, ocm_inst_size);
 144                 return -ENOMEM;
 145 #endif
 146         }
 147
 148         mod->arch.ocm_inst = ocm_inst;
 149         mod->arch.ocm_inst_size = ocm_inst_size;
 150
 151         printk(KERN_INFO
 152                "module %s: OCM instruction memory allocation of %d @%p\n",
 153                mod->name, mod->arch.ocm_inst_size, mod->arch.ocm_inst);
 154
 155         for (s = sechdrs; s < sechdrs_end; ++s) {
 156                 if (strncmp(".ocm_text", secstrings + s->sh_name, 9) == 0) {
 157                         memcpy(ocm_inst, (void *)s->sh_addr, s->sh_size);
 158                         s->sh_flags &= ~SHF_ALLOC;
 159                         s->sh_addr = (unsigned long)ocm_inst;
 160                         ocm_inst += s->sh_size;
 161                 }
 162         }
 163
 164         return 0;
 165 }
 166
 167 int apply_relocate(Elf32_Shdr *sechdrs,
 168                    const char *strtab,
 169                    unsigned int symindex,
 170                    unsigned int relsec,
 171                    struct module *me)
 172 {
 173         DEBUGP("Invalid Applying relocate section %u to %u\n", relsec,
 174                sechdrs[relsec].sh_info);
 175         return -EINVAL;
 176 }
 177
 178 int apply_relocate_add(Elf32_Shdr *sechdrs,
 179                        const char *strtab,
 180                        unsigned int symindex,
 181                        unsigned int relsec,
 182                        struct module *me)
 183 {
 184         unsigned int i;
 185         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
 186         Elf32_Sym *sym;
 187         uint32_t *location;
 188         uint32_t insn;
 189
 190         DEBUGP("Applying relocate_add section %u to %u\n", relsec,
 191                sechdrs[relsec].sh_info);
 192         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 193                 uint32_t v;
 194                 const int elf32_rtype = ELF32_R_TYPE(rel[i].r_info);
 195
 196                 /* This is where to make the change */
 197                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
 198                         + rel[i].r_offset;
 199                 /* This is the symbol it is referring to.  Note that all
 200                    undefined symbols have been resolved.  */
 201                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 202                         + ELF32_R_SYM(rel[i].r_info);
 203
 204                 v = rel[i].r_addend + sym->st_value;
 205
 206
 207                 switch (elf32_rtype) {
 208                 case R_UBICOM32_32:
 209                 {
 210                         /*
 211                          * Store the 32 bit relocation as is.
 212                          */
 213                         *location = v;
 214                         break;
 215                 }
 216                 case R_UBICOM32_HI24:
 217                 {
 218                         /*
 219                          * 24 bit relocation that is part of the MOVEAI
 220                          * instruction. The 24 bits come from bits 7 - 30 of the
 221                          * relocation. Theses bits eventually get split into 2
 222                          * fields in the instruction encoding.
 223                          *
 224                          * - Bits 7 - 27 of the relocation are encoded into bits
 225                          * 0 - 20 of the instruction.
 226                          *
 227                          *  - Bits 28 - 30 of the relocation are encoded into
 228                          *  bit 24 - 26 of the instruction.
 229                          */
 230                         uint32_t valid24 = (v >> 7) & 0xffffff;
 231                         insn = *location;
 232
 233                         insn &= ~(0x1fffff | (0x7 << 24));
 234                         insn |= (valid24 & 0x1fffff);
 235                         insn |= ((valid24 & 0xe00000) << 3);
 236                         *location = insn;
 237                 }
 238                 break;
 239                 case R_UBICOM32_LO7_S:
 240                 case R_UBICOM32_LO7_2_S:
 241                 case R_UBICOM32_LO7_4_S:
 242                 {
 243                         /*
 244                          * Bits 0 - 6 of the relocation are encoded into the
 245                          * 7bit unsigned immediate fields of the SOURCE-1 field
 246                          * of the instruction.  The immediate value is left
 247                          * shifted by (0, 1, 2) based on the operand size.
 248                          */
 249                         uint32_t valid7 = v & 0x7f;
 250                         insn = *location;
 251
 252                         if (elf32_rtype == R_UBICOM32_LO7_2_S) {
 253                                 valid7 >>= 1;
 254                         } else if (elf32_rtype == R_UBICOM32_LO7_4_S) {
 255                                 valid7 >>= 2;
 256                         }
 257
 258                         insn &= ~(0x1f | (0x3 << 8));
 259                         insn |= (valid7 & 0x1f);
 260                         insn |= ((valid7 & 0x60) << 3);
 261                         *location = insn;
 262                 }
 263                 break;
 264                 case R_UBICOM32_LO7_D:
 265                 case R_UBICOM32_LO7_2_D:
 266                 case R_UBICOM32_LO7_4_D:
 267                 {
 268                         /*
 269                          * Bits 0 - 6 of the relocation are encoded into the
 270                          * 7bit unsigned immediate fields of the DESTINATION
 271                          * field of the instruction.  The immediate value is
 272                          * left shifted by (0, 1, 2) based on the operand size.
 273                          */
 274                         uint32_t valid7 = v & 0x7f;
 275                         insn = *location;
 276
 277                         if (elf32_rtype == R_UBICOM32_LO7_2_D) {
 278                                 valid7 >>= 1;
 279                         } else if (elf32_rtype == R_UBICOM32_LO7_4_D) {
 280                                 valid7 >>= 2;
 281                         }
 282
 283                         insn &= ~((0x1f | (0x3 << 8)) << 16);
 284                         insn |= ((valid7 & 0x1f) << 16);
 285                         insn |= ((valid7 & 0x60) << 19);
 286                         *location = insn;
 287                 }
 288                 break;
 289                 case R_UBICOM32_LO7_CALLI:
 290                 case R_UBICOM32_LO16_CALLI:
 291                 {
 292                         /*
 293                          * Extract the offset for a CALLI instruction. The
 294                          * offsets can be either 7 bits or 18 bits. Since all
 295                          * instructions in ubicom32 architecture are at work
 296                          * aligned addresses the truncated offset is right
 297                          * shifted by 2 before being encoded in the instruction.
 298                          */
 299                         uint32_t val;
 300                         if (elf32_rtype == R_UBICOM32_LO7_CALLI) {
 301                                 val  = v & 0x7f;
 302                         } else {
 303                                 val  = v & 0x3ffff;
 304                         }
 305
 306                         val >>= 2;
 307
 308                         insn = *location;
 309
 310                         insn &= ~0x071f071f;
 311                         insn |= (val & 0x1f) << 0;
 312                         val >>= 5;
 313                         insn |= (val & 0x07) << 8;
 314                         val >>= 3;
 315                         insn |= (val & 0x1f) << 16;
 316                         val >>= 5;
 317                         insn |= (val & 0x07) << 24;
 318                         *location = insn;
 319                 }
 320                 break;
 321                 case R_UBICOM32_24_PCREL:
 322                 {
 323                         /*
 324                          * Extract 26 bit signed PC relative offset for CALL
 325                          * instructions. Since instruction addresses are word
 326                          * aligned the offset is right shited by 2 before
 327                          * encoding into instruction.
 328                          */
 329                         int32_t val = v - (int32_t)location;
 330
 331                         /*
 332                          * Check that the top 7 bits are all equal to the sign
 333                          * bit (26), i.e all 0's or all 1's.  If they are not then
 334                          * the absolute difference is greater than 25 bits.
 335                          */
 336                         if (((uint32_t)val & 0xFE000000) != 0xFE000000 &&
 337                                 ((uint32_t)val & 0xFE000000) != 0x0) {
 338                                 /*
 339                                  * The relocation is beyond our addressable
 340                                  * range with a 26 bit call.
 341                                  */
 342                                 printk(KERN_ERR "module %s: PC Relative "
 343                                         "relocation out of range: "
 344                                         "%u (%x->%x, %x)\n",
 345                                         me->name, elf32_rtype,
 346                                         v, (uint32_t) location, val);
 347                                 return -ENOEXEC;
 348                         }
 349
 350                         val = (val & 0x3ffffff) >> 2;
 351                         insn = *location;
 352                         insn = insn & 0xf8e00000;
 353
 354                         insn |= (val >> 21) << 24;
 355                         insn |= (val & 0x1fffff);
 356                         *location = insn;
 357                 }
 358                 break;
 359                 case R_UBICOM32_LO16:
 360                 case R_UBICOM32_HI16:
 361                 {
 362                         /*
 363                          * 16 bit immediate value that is encoded into bit 0 -
 364                          * 15 of the instruction.
 365                          */
 366                         uint32_t val;
 367
 368                         if (elf32_rtype == R_UBICOM32_LO16) {
 369                                 val  = v & 0xffff;
 370                         } else {
 371                                 val  = (v >> 16) & 0xffff;
 372                         }
 373
 374                         insn = *location;
 375                         insn &= 0xffff0000;
 376
 377                         insn |= val;
 378                         *location = insn;
 379                 }
 380                 break;
 381                 case R_UBICOM32_21_PCREL:
 382                 {
 383                         /*
 384                          * Extract 23 bit signed PC relative offset for JMP<cc>
 385                          * instructions. Since instruction addresses are word
 386                          * aligned the offset is right shited by 2 before
 387                          * encoding into instruction.
 388                          */
 389                         int32_t val = v - (int32_t)location;
 390
 391                         val = (val & 0x7fffff) >> 2;
 392                         insn = *location;
 393                         insn = insn & 0xffe00000;
 394
 395                         insn |= (val >> 21) << 24;
 396                         insn |= val;
 397                         *location = insn;
 398                 }
 399                 break;
 400                 default:
 401                         BUG();
 402                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 403                                me->name, elf32_rtype);
 404                         return -ENOEXEC;
 405                 }
 406         }
 407         return 0;
 408 }
 409
 410 int module_finalize(const Elf_Ehdr *hdr,
 411                     const Elf_Shdr *sechdrs,
 412                     struct module *mod)
 413 {
 414         unsigned int i, strindex = 0, symindex = 0;
 415         char *secstrings;
 416         int err;
 417
 418         err = module_bug_finalize(hdr, sechdrs, mod);
 419         if (err)
 420                 return err;
 421
 422         if (!mod->arch.ocm_inst) {
 423                 /*
 424                  * No OCM code, so nothing more to do.
 425                  */
 426                 return 0;
 427         }
 428
 429         secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 430
 431         for (i = 1; i < hdr->e_shnum; i++) {
 432                 /* Internal symbols and strings. */
 433                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
 434                         symindex = i;
 435                         strindex = sechdrs[i].sh_link;
 436                 }
 437         }
 438
 439         for (i = 1; i < hdr->e_shnum; i++) {
 440                 const char *strtab = (char *)sechdrs[strindex].sh_addr;
 441                 unsigned int info = sechdrs[i].sh_info;
 442
 443                 /* Not a valid relocation section? */
 444                 if (info >= hdr->e_shnum)
 445                         continue;
 446
 447                 if ((sechdrs[i].sh_type == SHT_RELA) &&
 448                     (strncmp(".rela.ocm_text",
 449                              secstrings + sechdrs[i].sh_name, 5 + 9) == 0)) {
 450                         err = apply_relocate_add((Elf_Shdr *) sechdrs, strtab,
 451                                                  symindex, i, mod);
 452                         if (err)
 453                                 return err;
 454                 }
 455         }
 456
 457         return 0;
 458 }
 459
 460 void module_arch_cleanup(struct module *mod)
 461 {
 462         module_bug_cleanup(mod);
 463 }