arch/arm64/kernel/insn.c

   1 /*
   2  * Copyright (C) 2013 Huawei Ltd.
   3  * Author: Jiang Liu <liuj97@gmail.com>
   4  *
   5  * Copyright (C) 2014-2016 Zi Shen Lim <zlim.lnx@gmail.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include <linux/bitops.h>
  20 #include <linux/bug.h>
  21 #include <linux/compiler.h>
  22 #include <linux/kernel.h>
  23 #include <linux/mm.h>
  24 #include <linux/smp.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/stop_machine.h>
  27 #include <linux/types.h>
  28 #include <linux/uaccess.h>
  29
  30 #include <asm/cacheflush.h>
  31 #include <asm/debug-monitors.h>
  32 #include <asm/fixmap.h>
  33 #include <asm/opcodes.h>
  34 #include <asm/insn.h>
  35
  36 #define AARCH64_INSN_SF_BIT     BIT(31)
  37 #define AARCH64_INSN_N_BIT      BIT(22)
  38
  39 static int aarch64_insn_encoding_class[] = {
  40         AARCH64_INSN_CLS_UNKNOWN,
  41         AARCH64_INSN_CLS_UNKNOWN,
  42         AARCH64_INSN_CLS_UNKNOWN,
  43         AARCH64_INSN_CLS_UNKNOWN,
  44         AARCH64_INSN_CLS_LDST,
  45         AARCH64_INSN_CLS_DP_REG,
  46         AARCH64_INSN_CLS_LDST,
  47         AARCH64_INSN_CLS_DP_FPSIMD,
  48         AARCH64_INSN_CLS_DP_IMM,
  49         AARCH64_INSN_CLS_DP_IMM,
  50         AARCH64_INSN_CLS_BR_SYS,
  51         AARCH64_INSN_CLS_BR_SYS,
  52         AARCH64_INSN_CLS_LDST,
  53         AARCH64_INSN_CLS_DP_REG,
  54         AARCH64_INSN_CLS_LDST,
  55         AARCH64_INSN_CLS_DP_FPSIMD,
  56 };
  57
  58 enum aarch64_insn_encoding_class __kprobes aarch64_get_insn_class(u32 insn)
  59 {
  60         return aarch64_insn_encoding_class[(insn >> 25) & 0xf];
  61 }
  62
  63 /* NOP is an alias of HINT */
  64 bool __kprobes aarch64_insn_is_nop(u32 insn)
  65 {
  66         if (!aarch64_insn_is_hint(insn))
  67                 return false;
  68
  69         switch (insn & 0xFE0) {
  70         case AARCH64_INSN_HINT_YIELD:
  71         case AARCH64_INSN_HINT_WFE:
  72         case AARCH64_INSN_HINT_WFI:
  73         case AARCH64_INSN_HINT_SEV:
  74         case AARCH64_INSN_HINT_SEVL:
  75                 return false;
  76         default:
  77                 return true;
  78         }
  79 }
  80
  81 bool aarch64_insn_is_branch_imm(u32 insn)
  82 {
  83         return (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn) ||
  84                 aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn) ||
  85                 aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
  86                 aarch64_insn_is_bcond(insn));
  87 }
  88
  89 static DEFINE_RAW_SPINLOCK(patch_lock);
  90
  91 static void __kprobes *patch_map(void *addr, int fixmap)
  92 {
  93         unsigned long uintaddr = (uintptr_t) addr;
  94         bool module = !core_kernel_text(uintaddr);
  95         struct page *page;
  96
  97         if (module && IS_ENABLED(CONFIG_DEBUG_SET_MODULE_RONX))
  98                 page = vmalloc_to_page(addr);
  99         else if (!module)
 100                 page = pfn_to_page(PHYS_PFN(__pa(addr)));
 101         else
 102                 return addr;
 103
 104         BUG_ON(!page);
 105         return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
 106                         (uintaddr & ~PAGE_MASK));
 107 }
 108
 109 static void __kprobes patch_unmap(int fixmap)
 110 {
 111         clear_fixmap(fixmap);
 112 }
 113 /*
 114  * In ARMv8-A, A64 instructions have a fixed length of 32 bits and are always
 115  * little-endian.
 116  */
 117 int __kprobes aarch64_insn_read(void *addr, u32 *insnp)
 118 {
 119         int ret;
 120         u32 val;
 121
 122         ret = probe_kernel_read(&val, addr, AARCH64_INSN_SIZE);
 123         if (!ret)
 124                 *insnp = le32_to_cpu(val);
 125
 126         return ret;
 127 }
 128
 129 static int __kprobes __aarch64_insn_write(void *addr, u32 insn)
 130 {
 131         void *waddr = addr;
 132         unsigned long flags = 0;
 133         int ret;
 134
 135         raw_spin_lock_irqsave(&patch_lock, flags);
 136         waddr = patch_map(addr, FIX_TEXT_POKE0);
 137
 138         ret = probe_kernel_write(waddr, &insn, AARCH64_INSN_SIZE);
 139
 140         patch_unmap(FIX_TEXT_POKE0);
 141         raw_spin_unlock_irqrestore(&patch_lock, flags);
 142
 143         return ret;
 144 }
 145
 146 int __kprobes aarch64_insn_write(void *addr, u32 insn)
 147 {
 148         insn = cpu_to_le32(insn);
 149         return __aarch64_insn_write(addr, insn);
 150 }
 151
 152 static bool __kprobes __aarch64_insn_hotpatch_safe(u32 insn)
 153 {
 154         if (aarch64_get_insn_class(insn) != AARCH64_INSN_CLS_BR_SYS)
 155                 return false;
 156
 157         return  aarch64_insn_is_b(insn) ||
 158                 aarch64_insn_is_bl(insn) ||
 159                 aarch64_insn_is_svc(insn) ||
 160                 aarch64_insn_is_hvc(insn) ||
 161                 aarch64_insn_is_smc(insn) ||
 162                 aarch64_insn_is_brk(insn) ||
 163                 aarch64_insn_is_nop(insn);
 164 }
 165
 166 bool __kprobes aarch64_insn_uses_literal(u32 insn)
 167 {
 168         /* ldr/ldrsw (literal), prfm */
 169
 170         return aarch64_insn_is_ldr_lit(insn) ||
 171                 aarch64_insn_is_ldrsw_lit(insn) ||
 172                 aarch64_insn_is_adr_adrp(insn) ||
 173                 aarch64_insn_is_prfm_lit(insn);
 174 }
 175
 176 bool __kprobes aarch64_insn_is_branch(u32 insn)
 177 {
 178         /* b, bl, cb*, tb*, b.cond, br, blr */
 179
 180         return aarch64_insn_is_b(insn) ||
 181                 aarch64_insn_is_bl(insn) ||
 182                 aarch64_insn_is_cbz(insn) ||
 183                 aarch64_insn_is_cbnz(insn) ||
 184                 aarch64_insn_is_tbz(insn) ||
 185                 aarch64_insn_is_tbnz(insn) ||
 186                 aarch64_insn_is_ret(insn) ||
 187                 aarch64_insn_is_br(insn) ||
 188                 aarch64_insn_is_blr(insn) ||
 189                 aarch64_insn_is_bcond(insn);
 190 }
 191
 192 /*
 193  * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a
 194  * Section B2.6.5 "Concurrent modification and execution of instructions":
 195  * Concurrent modification and execution of instructions can lead to the
 196  * resulting instruction performing any behavior that can be achieved by
 197  * executing any sequence of instructions that can be executed from the
 198  * same Exception level, except where the instruction before modification
 199  * and the instruction after modification is a B, BL, NOP, BKPT, SVC, HVC,
 200  * or SMC instruction.
 201  */
 202 bool __kprobes aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn)
 203 {
 204         return __aarch64_insn_hotpatch_safe(old_insn) &&
 205                __aarch64_insn_hotpatch_safe(new_insn);
 206 }
 207
 208 int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn)
 209 {
 210         u32 *tp = addr;
 211         int ret;
 212
 213         /* A64 instructions must be word aligned */
 214         if ((uintptr_t)tp & 0x3)
 215                 return -EINVAL;
 216
 217         ret = aarch64_insn_write(tp, insn);
 218         if (ret == 0)
 219                 flush_icache_range((uintptr_t)tp,
 220                                    (uintptr_t)tp + AARCH64_INSN_SIZE);
 221
 222         return ret;
 223 }
 224
 225 struct aarch64_insn_patch {
 226         void            **text_addrs;
 227         u32             *new_insns;
 228         int             insn_cnt;
 229         atomic_t        cpu_count;
 230 };
 231
 232 static int __kprobes aarch64_insn_patch_text_cb(void *arg)
 233 {
 234         int i, ret = 0;
 235         struct aarch64_insn_patch *pp = arg;
 236
 237         /* The first CPU becomes master */
 238         if (atomic_inc_return(&pp->cpu_count) == 1) {
 239                 for (i = 0; ret == 0 && i < pp->insn_cnt; i++)
 240                         ret = aarch64_insn_patch_text_nosync(pp->text_addrs[i],
 241                                                              pp->new_insns[i]);
 242                 /*
 243                  * aarch64_insn_patch_text_nosync() calls flush_icache_range(),
 244                  * which ends with "dsb; isb" pair guaranteeing global
 245                  * visibility.
 246                  */
 247                 /* Notify other processors with an additional increment. */
 248                 atomic_inc(&pp->cpu_count);
 249         } else {
 250                 while (atomic_read(&pp->cpu_count) <= num_online_cpus())
 251                         cpu_relax();
 252                 isb();
 253         }
 254
 255         return ret;
 256 }
 257
 258 int __kprobes aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt)
 259 {
 260         struct aarch64_insn_patch patch = {
 261                 .text_addrs = addrs,
 262                 .new_insns = insns,
 263                 .insn_cnt = cnt,
 264                 .cpu_count = ATOMIC_INIT(0),
 265         };
 266
 267         if (cnt <= 0)
 268                 return -EINVAL;
 269
 270         return stop_machine(aarch64_insn_patch_text_cb, &patch,
 271                             cpu_online_mask);
 272 }
 273
 274 int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)
 275 {
 276         int ret;
 277         u32 insn;
 278
 279         /* Unsafe to patch multiple instructions without synchronizaiton */
 280         if (cnt == 1) {
 281                 ret = aarch64_insn_read(addrs[0], &insn);
 282                 if (ret)
 283                         return ret;
 284
 285                 if (aarch64_insn_hotpatch_safe(insn, insns[0])) {
 286                         /*
 287                          * ARMv8 architecture doesn't guarantee all CPUs see
 288                          * the new instruction after returning from function
 289                          * aarch64_insn_patch_text_nosync(). So send IPIs to
 290                          * all other CPUs to achieve instruction
 291                          * synchronization.
 292                          */
 293                         ret = aarch64_insn_patch_text_nosync(addrs[0], insns[0]);
 294                         kick_all_cpus_sync();
 295                         return ret;
 296                 }
 297         }
 298
 299         return aarch64_insn_patch_text_sync(addrs, insns, cnt);
 300 }
 301
 302 static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type,
 303                                                 u32 *maskp, int *shiftp)
 304 {
 305         u32 mask;
 306         int shift;
 307
 308         switch (type) {
 309         case AARCH64_INSN_IMM_26:
 310                 mask = BIT(26) - 1;
 311                 shift = 0;
 312                 break;
 313         case AARCH64_INSN_IMM_19:
 314                 mask = BIT(19) - 1;
 315                 shift = 5;
 316                 break;
 317         case AARCH64_INSN_IMM_16:
 318                 mask = BIT(16) - 1;
 319                 shift = 5;
 320                 break;
 321         case AARCH64_INSN_IMM_14:
 322                 mask = BIT(14) - 1;
 323                 shift = 5;
 324                 break;
 325         case AARCH64_INSN_IMM_12:
 326                 mask = BIT(12) - 1;
 327                 shift = 10;
 328                 break;
 329         case AARCH64_INSN_IMM_9:
 330                 mask = BIT(9) - 1;
 331                 shift = 12;
 332                 break;
 333         case AARCH64_INSN_IMM_7:
 334                 mask = BIT(7) - 1;
 335                 shift = 15;
 336                 break;
 337         case AARCH64_INSN_IMM_6:
 338         case AARCH64_INSN_IMM_S:
 339                 mask = BIT(6) - 1;
 340                 shift = 10;
 341                 break;
 342         case AARCH64_INSN_IMM_R:
 343                 mask = BIT(6) - 1;
 344                 shift = 16;
 345                 break;
 346         default:
 347                 return -EINVAL;
 348         }
 349
 350         *maskp = mask;
 351         *shiftp = shift;
 352
 353         return 0;
 354 }
 355
 356 #define ADR_IMM_HILOSPLIT       2
 357 #define ADR_IMM_SIZE            SZ_2M
 358 #define ADR_IMM_LOMASK          ((1 << ADR_IMM_HILOSPLIT) - 1)
 359 #define ADR_IMM_HIMASK          ((ADR_IMM_SIZE >> ADR_IMM_HILOSPLIT) - 1)
 360 #define ADR_IMM_LOSHIFT         29
 361 #define ADR_IMM_HISHIFT         5
 362
 363 u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn)
 364 {
 365         u32 immlo, immhi, mask;
 366         int shift;
 367
 368         switch (type) {
 369         case AARCH64_INSN_IMM_ADR:
 370                 shift = 0;
 371                 immlo = (insn >> ADR_IMM_LOSHIFT) & ADR_IMM_LOMASK;
 372                 immhi = (insn >> ADR_IMM_HISHIFT) & ADR_IMM_HIMASK;
 373                 insn = (immhi << ADR_IMM_HILOSPLIT) | immlo;
 374                 mask = ADR_IMM_SIZE - 1;
 375                 break;
 376         default:
 377                 if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
 378                         pr_err("aarch64_insn_decode_immediate: unknown immediate encoding %d\n",
 379                                type);
 380                         return 0;
 381                 }
 382         }
 383
 384         return (insn >> shift) & mask;
 385 }
 386
 387 u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
 388                                   u32 insn, u64 imm)
 389 {
 390         u32 immlo, immhi, mask;
 391         int shift;
 392
 393         if (insn == AARCH64_BREAK_FAULT)
 394                 return AARCH64_BREAK_FAULT;
 395
 396         switch (type) {
 397         case AARCH64_INSN_IMM_ADR:
 398                 shift = 0;
 399                 immlo = (imm & ADR_IMM_LOMASK) << ADR_IMM_LOSHIFT;
 400                 imm >>= ADR_IMM_HILOSPLIT;
 401                 immhi = (imm & ADR_IMM_HIMASK) << ADR_IMM_HISHIFT;
 402                 imm = immlo | immhi;
 403                 mask = ((ADR_IMM_LOMASK << ADR_IMM_LOSHIFT) |
 404                         (ADR_IMM_HIMASK << ADR_IMM_HISHIFT));
 405                 break;
 406         default:
 407                 if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
 408                         pr_err("aarch64_insn_encode_immediate: unknown immediate encoding %d\n",
 409                                type);
 410                         return AARCH64_BREAK_FAULT;
 411                 }
 412         }
 413
 414         /* Update the immediate field. */
 415         insn &= ~(mask << shift);
 416         insn |= (imm & mask) << shift;
 417
 418         return insn;
 419 }
 420
 421 static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
 422                                         u32 insn,
 423                                         enum aarch64_insn_register reg)
 424 {
 425         int shift;
 426
 427         if (insn == AARCH64_BREAK_FAULT)
 428                 return AARCH64_BREAK_FAULT;
 429
 430         if (reg < AARCH64_INSN_REG_0 || reg > AARCH64_INSN_REG_SP) {
 431                 pr_err("%s: unknown register encoding %d\n", __func__, reg);
 432                 return AARCH64_BREAK_FAULT;
 433         }
 434
 435         switch (type) {
 436         case AARCH64_INSN_REGTYPE_RT:
 437         case AARCH64_INSN_REGTYPE_RD:
 438                 shift = 0;
 439                 break;
 440         case AARCH64_INSN_REGTYPE_RN:
 441                 shift = 5;
 442                 break;
 443         case AARCH64_INSN_REGTYPE_RT2:
 444         case AARCH64_INSN_REGTYPE_RA:
 445                 shift = 10;
 446                 break;
 447         case AARCH64_INSN_REGTYPE_RM:
 448                 shift = 16;
 449                 break;
 450         default:
 451                 pr_err("%s: unknown register type encoding %d\n", __func__,
 452                        type);
 453                 return AARCH64_BREAK_FAULT;
 454         }
 455
 456         insn &= ~(GENMASK(4, 0) << shift);
 457         insn |= reg << shift;
 458
 459         return insn;
 460 }
 461
 462 static u32 aarch64_insn_encode_ldst_size(enum aarch64_insn_size_type type,
 463                                          u32 insn)
 464 {
 465         u32 size;
 466
 467         switch (type) {
 468         case AARCH64_INSN_SIZE_8:
 469                 size = 0;
 470                 break;
 471         case AARCH64_INSN_SIZE_16:
 472                 size = 1;
 473                 break;
 474         case AARCH64_INSN_SIZE_32:
 475                 size = 2;
 476                 break;
 477         case AARCH64_INSN_SIZE_64:
 478                 size = 3;
 479                 break;
 480         default:
 481                 pr_err("%s: unknown size encoding %d\n", __func__, type);
 482                 return AARCH64_BREAK_FAULT;
 483         }
 484
 485         insn &= ~GENMASK(31, 30);
 486         insn |= size << 30;
 487
 488         return insn;
 489 }
 490
 491 static inline long branch_imm_common(unsigned long pc, unsigned long addr,
 492                                      long range)
 493 {
 494         long offset;
 495
 496         if ((pc & 0x3) || (addr & 0x3)) {
 497                 pr_err("%s: A64 instructions must be word aligned\n", __func__);
 498                 return range;
 499         }
 500
 501         offset = ((long)addr - (long)pc);
 502
 503         if (offset < -range || offset >= range) {
 504                 pr_err("%s: offset out of range\n", __func__);
 505                 return range;
 506         }
 507
 508         return offset;
 509 }
 510
 511 u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr,
 512                                           enum aarch64_insn_branch_type type)
 513 {
 514         u32 insn;
 515         long offset;
 516
 517         /*
 518          * B/BL support [-128M, 128M) offset
 519          * ARM64 virtual address arrangement guarantees all kernel and module
 520          * texts are within +/-128M.
 521          */
 522         offset = branch_imm_common(pc, addr, SZ_128M);
 523         if (offset >= SZ_128M)
 524                 return AARCH64_BREAK_FAULT;
 525
 526         switch (type) {
 527         case AARCH64_INSN_BRANCH_LINK:
 528                 insn = aarch64_insn_get_bl_value();
 529                 break;
 530         case AARCH64_INSN_BRANCH_NOLINK:
 531                 insn = aarch64_insn_get_b_value();
 532                 break;
 533         default:
 534                 pr_err("%s: unknown branch encoding %d\n", __func__, type);
 535                 return AARCH64_BREAK_FAULT;
 536         }
 537
 538         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
 539                                              offset >> 2);
 540 }
 541
 542 u32 aarch64_insn_gen_comp_branch_imm(unsigned long pc, unsigned long addr,
 543                                      enum aarch64_insn_register reg,
 544                                      enum aarch64_insn_variant variant,
 545                                      enum aarch64_insn_branch_type type)
 546 {
 547         u32 insn;
 548         long offset;
 549
 550         offset = branch_imm_common(pc, addr, SZ_1M);
 551         if (offset >= SZ_1M)
 552                 return AARCH64_BREAK_FAULT;
 553
 554         switch (type) {
 555         case AARCH64_INSN_BRANCH_COMP_ZERO:
 556                 insn = aarch64_insn_get_cbz_value();
 557                 break;
 558         case AARCH64_INSN_BRANCH_COMP_NONZERO:
 559                 insn = aarch64_insn_get_cbnz_value();
 560                 break;
 561         default:
 562                 pr_err("%s: unknown branch encoding %d\n", __func__, type);
 563                 return AARCH64_BREAK_FAULT;
 564         }
 565
 566         switch (variant) {
 567         case AARCH64_INSN_VARIANT_32BIT:
 568                 break;
 569         case AARCH64_INSN_VARIANT_64BIT:
 570                 insn |= AARCH64_INSN_SF_BIT;
 571                 break;
 572         default:
 573                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
 574                 return AARCH64_BREAK_FAULT;
 575         }
 576
 577         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
 578
 579         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
 580                                              offset >> 2);
 581 }
 582
 583 u32 aarch64_insn_gen_cond_branch_imm(unsigned long pc, unsigned long addr,
 584                                      enum aarch64_insn_condition cond)
 585 {
 586         u32 insn;
 587         long offset;
 588
 589         offset = branch_imm_common(pc, addr, SZ_1M);
 590
 591         insn = aarch64_insn_get_bcond_value();
 592
 593         if (cond < AARCH64_INSN_COND_EQ || cond > AARCH64_INSN_COND_AL) {
 594                 pr_err("%s: unknown condition encoding %d\n", __func__, cond);
 595                 return AARCH64_BREAK_FAULT;
 596         }
 597         insn |= cond;
 598
 599         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
 600                                              offset >> 2);
 601 }
 602
 603 u32 __kprobes aarch64_insn_gen_hint(enum aarch64_insn_hint_op op)
 604 {
 605         return aarch64_insn_get_hint_value() | op;
 606 }
 607
 608 u32 __kprobes aarch64_insn_gen_nop(void)
 609 {
 610         return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP);
 611 }
 612
 613 u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,
 614                                 enum aarch64_insn_branch_type type)
 615 {
 616         u32 insn;
 617
 618         switch (type) {
 619         case AARCH64_INSN_BRANCH_NOLINK:
 620                 insn = aarch64_insn_get_br_value();
 621                 break;
 622         case AARCH64_INSN_BRANCH_LINK:
 623                 insn = aarch64_insn_get_blr_value();
 624                 break;
 625         case AARCH64_INSN_BRANCH_RETURN:
 626                 insn = aarch64_insn_get_ret_value();
 627                 break;
 628         default:
 629                 pr_err("%s: unknown branch encoding %d\n", __func__, type);
 630                 return AARCH64_BREAK_FAULT;
 631         }
 632
 633         return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, reg);
 634 }
 635
 636 u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,
 637                                     enum aarch64_insn_register base,
 638                                     enum aarch64_insn_register offset,
 639                                     enum aarch64_insn_size_type size,
 640                                     enum aarch64_insn_ldst_type type)
 641 {
 642         u32 insn;
 643
 644         switch (type) {
 645         case AARCH64_INSN_LDST_LOAD_REG_OFFSET:
 646                 insn = aarch64_insn_get_ldr_reg_value();
 647                 break;
 648         case AARCH64_INSN_LDST_STORE_REG_OFFSET:
 649                 insn = aarch64_insn_get_str_reg_value();
 650                 break;
 651         default:
 652                 pr_err("%s: unknown load/store encoding %d\n", __func__, type);
 653                 return AARCH64_BREAK_FAULT;
 654         }
 655
 656         insn = aarch64_insn_encode_ldst_size(size, insn);
 657
 658         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
 659
 660         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
 661                                             base);
 662
 663         return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
 664                                             offset);
 665 }
 666
 667 u32 aarch64_insn_gen_load_store_pair(enum aarch64_insn_register reg1,
 668                                      enum aarch64_insn_register reg2,
 669                                      enum aarch64_insn_register base,
 670                                      int offset,
 671                                      enum aarch64_insn_variant variant,
 672                                      enum aarch64_insn_ldst_type type)
 673 {
 674         u32 insn;
 675         int shift;
 676
 677         switch (type) {
 678         case AARCH64_INSN_LDST_LOAD_PAIR_PRE_INDEX:
 679                 insn = aarch64_insn_get_ldp_pre_value();
 680                 break;
 681         case AARCH64_INSN_LDST_STORE_PAIR_PRE_INDEX:
 682                 insn = aarch64_insn_get_stp_pre_value();
 683                 break;
 684         case AARCH64_INSN_LDST_LOAD_PAIR_POST_INDEX:
 685                 insn = aarch64_insn_get_ldp_post_value();
 686                 break;
 687         case AARCH64_INSN_LDST_STORE_PAIR_POST_INDEX:
 688                 insn = aarch64_insn_get_stp_post_value();
 689                 break;
 690         default:
 691                 pr_err("%s: unknown load/store encoding %d\n", __func__, type);
 692                 return AARCH64_BREAK_FAULT;
 693         }
 694
 695         switch (variant) {
 696         case AARCH64_INSN_VARIANT_32BIT:
 697                 if ((offset & 0x3) || (offset < -256) || (offset > 252)) {
 698                         pr_err("%s: offset must be multiples of 4 in the range of [-256, 252] %d\n",
 699                                __func__, offset);
 700                         return AARCH64_BREAK_FAULT;
 701                 }
 702                 shift = 2;
 703                 break;
 704         case AARCH64_INSN_VARIANT_64BIT:
 705                 if ((offset & 0x7) || (offset < -512) || (offset > 504)) {
 706                         pr_err("%s: offset must be multiples of 8 in the range of [-512, 504] %d\n",
 707                                __func__, offset);
 708                         return AARCH64_BREAK_FAULT;
 709                 }
 710                 shift = 3;
 711                 insn |= AARCH64_INSN_SF_BIT;
 712                 break;
 713         default:
 714                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
 715                 return AARCH64_BREAK_FAULT;
 716         }
 717
 718         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
 719                                             reg1);
 720
 721         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
 722                                             reg2);
 723
 724         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
 725                                             base);
 726
 727         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_7, insn,
 728                                              offset >> shift);
 729 }
 730
 731 u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst,
 732                                  enum aarch64_insn_register src,
 733                                  int imm, enum aarch64_insn_variant variant,
 734                                  enum aarch64_insn_adsb_type type)
 735 {
 736         u32 insn;
 737
 738         switch (type) {
 739         case AARCH64_INSN_ADSB_ADD:
 740                 insn = aarch64_insn_get_add_imm_value();
 741                 break;
 742         case AARCH64_INSN_ADSB_SUB:
 743                 insn = aarch64_insn_get_sub_imm_value();
 744                 break;
 745         case AARCH64_INSN_ADSB_ADD_SETFLAGS:
 746                 insn = aarch64_insn_get_adds_imm_value();
 747                 break;
 748         case AARCH64_INSN_ADSB_SUB_SETFLAGS:
 749                 insn = aarch64_insn_get_subs_imm_value();
 750                 break;
 751         default:
 752                 pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
 753                 return AARCH64_BREAK_FAULT;
 754         }
 755
 756         switch (variant) {
 757         case AARCH64_INSN_VARIANT_32BIT:
 758                 break;
 759         case AARCH64_INSN_VARIANT_64BIT:
 760                 insn |= AARCH64_INSN_SF_BIT;
 761                 break;
 762         default:
 763                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
 764                 return AARCH64_BREAK_FAULT;
 765         }
 766
 767         if (imm & ~(SZ_4K - 1)) {
 768                 pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
 769                 return AARCH64_BREAK_FAULT;
 770         }
 771
 772         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
 773
 774         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
 775
 776         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, imm);
 777 }
 778
 779 u32 aarch64_insn_gen_bitfield(enum aarch64_insn_register dst,
 780                               enum aarch64_insn_register src,
 781                               int immr, int imms,
 782                               enum aarch64_insn_variant variant,
 783                               enum aarch64_insn_bitfield_type type)
 784 {
 785         u32 insn;
 786         u32 mask;
 787
 788         switch (type) {
 789         case AARCH64_INSN_BITFIELD_MOVE:
 790                 insn = aarch64_insn_get_bfm_value();
 791                 break;
 792         case AARCH64_INSN_BITFIELD_MOVE_UNSIGNED:
 793                 insn = aarch64_insn_get_ubfm_value();
 794                 break;
 795         case AARCH64_INSN_BITFIELD_MOVE_SIGNED:
 796                 insn = aarch64_insn_get_sbfm_value();
 797                 break;
 798         default:
 799                 pr_err("%s: unknown bitfield encoding %d\n", __func__, type);
 800                 return AARCH64_BREAK_FAULT;
 801         }
 802
 803         switch (variant) {
 804         case AARCH64_INSN_VARIANT_32BIT:
 805                 mask = GENMASK(4, 0);
 806                 break;
 807         case AARCH64_INSN_VARIANT_64BIT:
 808                 insn |= AARCH64_INSN_SF_BIT | AARCH64_INSN_N_BIT;
 809                 mask = GENMASK(5, 0);
 810                 break;
 811         default:
 812                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
 813                 return AARCH64_BREAK_FAULT;
 814         }
 815
 816         if (immr & ~mask) {
 817                 pr_err("%s: invalid immr encoding %d\n", __func__, immr);
 818                 return AARCH64_BREAK_FAULT;
 819         }
 820         if (imms & ~mask) {
 821                 pr_err("%s: invalid imms encoding %d\n", __func__, imms);
 822                 return AARCH64_BREAK_FAULT;
 823         }
 824
 825         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
 826
 827         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
 828
 829         insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr);
 830
 831         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms);
 832 }
 833
 834 u32 aarch64_insn_gen_movewide(enum aarch64_insn_register dst,
 835                               int imm, int shift,
 836                               enum aarch64_insn_variant variant,
 837                               enum aarch64_insn_movewide_type type)
 838 {
 839         u32 insn;
 840
 841         switch (type) {
 842         case AARCH64_INSN_MOVEWIDE_ZERO:
 843                 insn = aarch64_insn_get_movz_value();
 844                 break;
 845         case AARCH64_INSN_MOVEWIDE_KEEP:
 846                 insn = aarch64_insn_get_movk_value();
 847                 break;
 848         case AARCH64_INSN_MOVEWIDE_INVERSE:
 849                 insn = aarch64_insn_get_movn_value();
 850                 break;
 851         default:
 852                 pr_err("%s: unknown movewide encoding %d\n", __func__, type);
 853                 return AARCH64_BREAK_FAULT;
 854         }
 855
 856         if (imm & ~(SZ_64K - 1)) {
 857                 pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
 858                 return AARCH64_BREAK_FAULT;
 859         }
 860
 861         switch (variant) {
 862         case AARCH64_INSN_VARIANT_32BIT:
 863                 if (shift != 0 && shift != 16) {
 864                         pr_err("%s: invalid shift encoding %d\n", __func__,
 865                                shift);
 866                         return AARCH64_BREAK_FAULT;
 867                 }
 868                 break;
 869         case AARCH64_INSN_VARIANT_64BIT:
 870                 insn |= AARCH64_INSN_SF_BIT;
 871                 if (shift != 0 && shift != 16 && shift != 32 && shift != 48) {
 872                         pr_err("%s: invalid shift encoding %d\n", __func__,
 873                                shift);
 874                         return AARCH64_BREAK_FAULT;
 875                 }
 876                 break;
 877         default:
 878                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
 879                 return AARCH64_BREAK_FAULT;
 880         }
 881
 882         insn |= (shift >> 4) << 21;
 883
 884         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
 885
 886         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_16, insn, imm);
 887 }
 888
 889 u32 aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,
 890                                          enum aarch64_insn_register src,
 891                                          enum aarch64_insn_register reg,
 892                                          int shift,
 893                                          enum aarch64_insn_variant variant,
 894                                          enum aarch64_insn_adsb_type type)
 895 {
 896         u32 insn;
 897
 898         switch (type) {
 899         case AARCH64_INSN_ADSB_ADD:
 900                 insn = aarch64_insn_get_add_value();
 901                 break;
 902         case AARCH64_INSN_ADSB_SUB:
 903                 insn = aarch64_insn_get_sub_value();
 904                 break;
 905         case AARCH64_INSN_ADSB_ADD_SETFLAGS:
 906                 insn = aarch64_insn_get_adds_value();
 907                 break;
 908         case AARCH64_INSN_ADSB_SUB_SETFLAGS:
 909                 insn = aarch64_insn_get_subs_value();
 910                 break;
 911         default:
 912                 pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
 913                 return AARCH64_BREAK_FAULT;
 914         }
 915
 916         switch (variant) {
 917         case AARCH64_INSN_VARIANT_32BIT:
 918                 if (shift & ~(SZ_32 - 1)) {
 919                         pr_err("%s: invalid shift encoding %d\n", __func__,
 920                                shift);
 921                         return AARCH64_BREAK_FAULT;
 922                 }
 923                 break;
 924         case AARCH64_INSN_VARIANT_64BIT:
 925                 insn |= AARCH64_INSN_SF_BIT;
 926                 if (shift & ~(SZ_64 - 1)) {
 927                         pr_err("%s: invalid shift encoding %d\n", __func__,
 928                                shift);
 929                         return AARCH64_BREAK_FAULT;
 930                 }
 931                 break;
 932         default:
 933                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
 934                 return AARCH64_BREAK_FAULT;
 935         }
 936
 937
 938         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
 939
 940         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
 941
 942         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
 943
 944         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
 945 }
 946
 947 u32 aarch64_insn_gen_data1(enum aarch64_insn_register dst,
 948                            enum aarch64_insn_register src,
 949                            enum aarch64_insn_variant variant,
 950                            enum aarch64_insn_data1_type type)
 951 {
 952         u32 insn;
 953
 954         switch (type) {
 955         case AARCH64_INSN_DATA1_REVERSE_16:
 956                 insn = aarch64_insn_get_rev16_value();
 957                 break;
 958         case AARCH64_INSN_DATA1_REVERSE_32:
 959                 insn = aarch64_insn_get_rev32_value();
 960                 break;
 961         case AARCH64_INSN_DATA1_REVERSE_64:
 962                 if (variant != AARCH64_INSN_VARIANT_64BIT) {
 963                         pr_err("%s: invalid variant for reverse64 %d\n",
 964                                __func__, variant);
 965                         return AARCH64_BREAK_FAULT;
 966                 }
 967                 insn = aarch64_insn_get_rev64_value();
 968                 break;
 969         default:
 970                 pr_err("%s: unknown data1 encoding %d\n", __func__, type);
 971                 return AARCH64_BREAK_FAULT;
 972         }
 973
 974         switch (variant) {
 975         case AARCH64_INSN_VARIANT_32BIT:
 976                 break;
 977         case AARCH64_INSN_VARIANT_64BIT:
 978                 insn |= AARCH64_INSN_SF_BIT;
 979                 break;
 980         default:
 981                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
 982                 return AARCH64_BREAK_FAULT;
 983         }
 984
 985         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
 986
 987         return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
 988 }
 989
 990 u32 aarch64_insn_gen_data2(enum aarch64_insn_register dst,
 991                            enum aarch64_insn_register src,
 992                            enum aarch64_insn_register reg,
 993                            enum aarch64_insn_variant variant,
 994                            enum aarch64_insn_data2_type type)
 995 {
 996         u32 insn;
 997
 998         switch (type) {
 999         case AARCH64_INSN_DATA2_UDIV:
1000                 insn = aarch64_insn_get_udiv_value();
1001                 break;
1002         case AARCH64_INSN_DATA2_SDIV:
1003                 insn = aarch64_insn_get_sdiv_value();
1004                 break;
1005         case AARCH64_INSN_DATA2_LSLV:
1006                 insn = aarch64_insn_get_lslv_value();
1007                 break;
1008         case AARCH64_INSN_DATA2_LSRV:
1009                 insn = aarch64_insn_get_lsrv_value();
1010                 break;
1011         case AARCH64_INSN_DATA2_ASRV:
1012                 insn = aarch64_insn_get_asrv_value();
1013                 break;
1014         case AARCH64_INSN_DATA2_RORV:
1015                 insn = aarch64_insn_get_rorv_value();
1016                 break;
1017         default:
1018                 pr_err("%s: unknown data2 encoding %d\n", __func__, type);
1019                 return AARCH64_BREAK_FAULT;
1020         }
1021
1022         switch (variant) {
1023         case AARCH64_INSN_VARIANT_32BIT:
1024                 break;
1025         case AARCH64_INSN_VARIANT_64BIT:
1026                 insn |= AARCH64_INSN_SF_BIT;
1027                 break;
1028         default:
1029                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1030                 return AARCH64_BREAK_FAULT;
1031         }
1032
1033         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1034
1035         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1036
1037         return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
1038 }
1039
1040 u32 aarch64_insn_gen_data3(enum aarch64_insn_register dst,
1041                            enum aarch64_insn_register src,
1042                            enum aarch64_insn_register reg1,
1043                            enum aarch64_insn_register reg2,
1044                            enum aarch64_insn_variant variant,
1045                            enum aarch64_insn_data3_type type)
1046 {
1047         u32 insn;
1048
1049         switch (type) {
1050         case AARCH64_INSN_DATA3_MADD:
1051                 insn = aarch64_insn_get_madd_value();
1052                 break;
1053         case AARCH64_INSN_DATA3_MSUB:
1054                 insn = aarch64_insn_get_msub_value();
1055                 break;
1056         default:
1057                 pr_err("%s: unknown data3 encoding %d\n", __func__, type);
1058                 return AARCH64_BREAK_FAULT;
1059         }
1060
1061         switch (variant) {
1062         case AARCH64_INSN_VARIANT_32BIT:
1063                 break;
1064         case AARCH64_INSN_VARIANT_64BIT:
1065                 insn |= AARCH64_INSN_SF_BIT;
1066                 break;
1067         default:
1068                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1069                 return AARCH64_BREAK_FAULT;
1070         }
1071
1072         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1073
1074         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RA, insn, src);
1075
1076         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
1077                                             reg1);
1078
1079         return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
1080                                             reg2);
1081 }
1082
1083 u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,
1084                                          enum aarch64_insn_register src,
1085                                          enum aarch64_insn_register reg,
1086                                          int shift,
1087                                          enum aarch64_insn_variant variant,
1088                                          enum aarch64_insn_logic_type type)
1089 {
1090         u32 insn;
1091
1092         switch (type) {
1093         case AARCH64_INSN_LOGIC_AND:
1094                 insn = aarch64_insn_get_and_value();
1095                 break;
1096         case AARCH64_INSN_LOGIC_BIC:
1097                 insn = aarch64_insn_get_bic_value();
1098                 break;
1099         case AARCH64_INSN_LOGIC_ORR:
1100                 insn = aarch64_insn_get_orr_value();
1101                 break;
1102         case AARCH64_INSN_LOGIC_ORN:
1103                 insn = aarch64_insn_get_orn_value();
1104                 break;
1105         case AARCH64_INSN_LOGIC_EOR:
1106                 insn = aarch64_insn_get_eor_value();
1107                 break;
1108         case AARCH64_INSN_LOGIC_EON:
1109                 insn = aarch64_insn_get_eon_value();
1110                 break;
1111         case AARCH64_INSN_LOGIC_AND_SETFLAGS:
1112                 insn = aarch64_insn_get_ands_value();
1113                 break;
1114         case AARCH64_INSN_LOGIC_BIC_SETFLAGS:
1115                 insn = aarch64_insn_get_bics_value();
1116                 break;
1117         default:
1118                 pr_err("%s: unknown logical encoding %d\n", __func__, type);
1119                 return AARCH64_BREAK_FAULT;
1120         }
1121
1122         switch (variant) {
1123         case AARCH64_INSN_VARIANT_32BIT:
1124                 if (shift & ~(SZ_32 - 1)) {
1125                         pr_err("%s: invalid shift encoding %d\n", __func__,
1126                                shift);
1127                         return AARCH64_BREAK_FAULT;
1128                 }
1129                 break;
1130         case AARCH64_INSN_VARIANT_64BIT:
1131                 insn |= AARCH64_INSN_SF_BIT;
1132                 if (shift & ~(SZ_64 - 1)) {
1133                         pr_err("%s: invalid shift encoding %d\n", __func__,
1134                                shift);
1135                         return AARCH64_BREAK_FAULT;
1136                 }
1137                 break;
1138         default:
1139                 pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1140                 return AARCH64_BREAK_FAULT;
1141         }
1142
1143
1144         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1145
1146         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1147
1148         insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
1149
1150         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
1151 }
1152
1153 /*
1154  * Decode the imm field of a branch, and return the byte offset as a
1155  * signed value (so it can be used when computing a new branch
1156  * target).
1157  */
1158 s32 aarch64_get_branch_offset(u32 insn)
1159 {
1160         s32 imm;
1161
1162         if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn)) {
1163                 imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_26, insn);
1164                 return (imm << 6) >> 4;
1165         }
1166
1167         if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
1168             aarch64_insn_is_bcond(insn)) {
1169                 imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_19, insn);
1170                 return (imm << 13) >> 11;
1171         }
1172
1173         if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn)) {
1174                 imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_14, insn);
1175                 return (imm << 18) >> 16;
1176         }
1177
1178         /* Unhandled instruction */
1179         BUG();
1180 }
1181
1182 /*
1183  * Encode the displacement of a branch in the imm field and return the
1184  * updated instruction.
1185  */
1186 u32 aarch64_set_branch_offset(u32 insn, s32 offset)
1187 {
1188         if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn))
1189                 return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
1190                                                      offset >> 2);
1191
1192         if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
1193             aarch64_insn_is_bcond(insn))
1194                 return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
1195                                                      offset >> 2);
1196
1197         if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn))
1198                 return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_14, insn,
1199                                                      offset >> 2);
1200
1201         /* Unhandled instruction */
1202         BUG();
1203 }
1204
1205 s32 aarch64_insn_adrp_get_offset(u32 insn)
1206 {
1207         BUG_ON(!aarch64_insn_is_adrp(insn));
1208         return aarch64_insn_decode_immediate(AARCH64_INSN_IMM_ADR, insn) << 12;
1209 }
1210
1211 u32 aarch64_insn_adrp_set_offset(u32 insn, s32 offset)
1212 {
1213         BUG_ON(!aarch64_insn_is_adrp(insn));
1214         return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn,
1215                                                 offset >> 12);
1216 }
1217
1218 /*
1219  * Extract the Op/CR data from a msr/mrs instruction.
1220  */
1221 u32 aarch64_insn_extract_system_reg(u32 insn)
1222 {
1223         return (insn & 0x1FFFE0) >> 5;
1224 }
1225
1226 bool aarch32_insn_is_wide(u32 insn)
1227 {
1228         return insn >= 0xe800;
1229 }
1230
1231 /*
1232  * Macros/defines for extracting register numbers from instruction.
1233  */
1234 u32 aarch32_insn_extract_reg_num(u32 insn, int offset)
1235 {
1236         return (insn & (0xf << offset)) >> offset;
1237 }
1238
1239 #define OPC2_MASK       0x7
1240 #define OPC2_OFFSET     5
1241 u32 aarch32_insn_mcr_extract_opc2(u32 insn)
1242 {
1243         return (insn & (OPC2_MASK << OPC2_OFFSET)) >> OPC2_OFFSET;
1244 }
1245
1246 #define CRM_MASK        0xf
1247 u32 aarch32_insn_mcr_extract_crm(u32 insn)
1248 {
1249         return insn & CRM_MASK;
1250 }
1251
1252 static bool __kprobes __check_eq(unsigned long pstate)
1253 {
1254         return (pstate & PSR_Z_BIT) != 0;
1255 }
1256
1257 static bool __kprobes __check_ne(unsigned long pstate)
1258 {
1259         return (pstate & PSR_Z_BIT) == 0;
1260 }
1261
1262 static bool __kprobes __check_cs(unsigned long pstate)
1263 {
1264         return (pstate & PSR_C_BIT) != 0;
1265 }
1266
1267 static bool __kprobes __check_cc(unsigned long pstate)
1268 {
1269         return (pstate & PSR_C_BIT) == 0;
1270 }
1271
1272 static bool __kprobes __check_mi(unsigned long pstate)
1273 {
1274         return (pstate & PSR_N_BIT) != 0;
1275 }
1276
1277 static bool __kprobes __check_pl(unsigned long pstate)
1278 {
1279         return (pstate & PSR_N_BIT) == 0;
1280 }
1281
1282 static bool __kprobes __check_vs(unsigned long pstate)
1283 {
1284         return (pstate & PSR_V_BIT) != 0;
1285 }
1286
1287 static bool __kprobes __check_vc(unsigned long pstate)
1288 {
1289         return (pstate & PSR_V_BIT) == 0;
1290 }
1291
1292 static bool __kprobes __check_hi(unsigned long pstate)
1293 {
1294         pstate &= ~(pstate >> 1);       /* PSR_C_BIT &= ~PSR_Z_BIT */
1295         return (pstate & PSR_C_BIT) != 0;
1296 }
1297
1298 static bool __kprobes __check_ls(unsigned long pstate)
1299 {
1300         pstate &= ~(pstate >> 1);       /* PSR_C_BIT &= ~PSR_Z_BIT */
1301         return (pstate & PSR_C_BIT) == 0;
1302 }
1303
1304 static bool __kprobes __check_ge(unsigned long pstate)
1305 {
1306         pstate ^= (pstate << 3);        /* PSR_N_BIT ^= PSR_V_BIT */
1307         return (pstate & PSR_N_BIT) == 0;
1308 }
1309
1310 static bool __kprobes __check_lt(unsigned long pstate)
1311 {
1312         pstate ^= (pstate << 3);        /* PSR_N_BIT ^= PSR_V_BIT */
1313         return (pstate & PSR_N_BIT) != 0;
1314 }
1315
1316 static bool __kprobes __check_gt(unsigned long pstate)
1317 {
1318         /*PSR_N_BIT ^= PSR_V_BIT */
1319         unsigned long temp = pstate ^ (pstate << 3);
1320
1321         temp |= (pstate << 1);  /*PSR_N_BIT |= PSR_Z_BIT */
1322         return (temp & PSR_N_BIT) == 0;
1323 }
1324
1325 static bool __kprobes __check_le(unsigned long pstate)
1326 {
1327         /*PSR_N_BIT ^= PSR_V_BIT */
1328         unsigned long temp = pstate ^ (pstate << 3);
1329
1330         temp |= (pstate << 1);  /*PSR_N_BIT |= PSR_Z_BIT */
1331         return (temp & PSR_N_BIT) != 0;
1332 }
1333
1334 static bool __kprobes __check_al(unsigned long pstate)
1335 {
1336         return true;
1337 }
1338
1339 /*
1340  * Note that the ARMv8 ARM calls condition code 0b1111 "nv", but states that
1341  * it behaves identically to 0b1110 ("al").
1342  */
1343 pstate_check_t * const aarch32_opcode_cond_checks[16] = {
1344         __check_eq, __check_ne, __check_cs, __check_cc,
1345         __check_mi, __check_pl, __check_vs, __check_vc,
1346         __check_hi, __check_ls, __check_ge, __check_lt,
1347         __check_gt, __check_le, __check_al, __check_al
1348 };