arch/sparc/kernel/unaligned_64.c

   1 /*
   2  * unaligned.c: Unaligned load/store trap handling with special
   3  *              cases for the kernel to do them more quickly.
   4  *
   5  * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
   6  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   7  */
   8
   9
  10 #include <linux/jiffies.h>
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/mm.h>
  14 #include <linux/module.h>
  15 #include <asm/asi.h>
  16 #include <asm/ptrace.h>
  17 #include <asm/pstate.h>
  18 #include <asm/processor.h>
  19 #include <asm/uaccess.h>
  20 #include <linux/smp.h>
  21 #include <linux/bitops.h>
  22 #include <linux/perf_event.h>
  23 #include <linux/ratelimit.h>
  24 #include <asm/fpumacro.h>
  25 #include <asm/cacheflush.h>
  26
  27 enum direction {
  28         load,    /* ld, ldd, ldh, ldsh */
  29         store,   /* st, std, sth, stsh */
  30         both,    /* Swap, ldstub, cas, ... */
  31         fpld,
  32         fpst,
  33         invalid,
  34 };
  35
  36 static inline enum direction decode_direction(unsigned int insn)
  37 {
  38         unsigned long tmp = (insn >> 21) & 1;
  39
  40         if (!tmp)
  41                 return load;
  42         else {
  43                 switch ((insn>>19)&0xf) {
  44                 case 15: /* swap* */
  45                         return both;
  46                 default:
  47                         return store;
  48                 }
  49         }
  50 }
  51
  52 /* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
  53 static inline int decode_access_size(struct pt_regs *regs, unsigned int insn)
  54 {
  55         unsigned int tmp;
  56
  57         tmp = ((insn >> 19) & 0xf);
  58         if (tmp == 11 || tmp == 14) /* ldx/stx */
  59                 return 8;
  60         tmp &= 3;
  61         if (!tmp)
  62                 return 4;
  63         else if (tmp == 3)
  64                 return 16;      /* ldd/std - Although it is actually 8 */
  65         else if (tmp == 2)
  66                 return 2;
  67         else {
  68                 printk("Impossible unaligned trap. insn=%08x\n", insn);
  69                 die_if_kernel("Byte sized unaligned access?!?!", regs);
  70
  71                 /* GCC should never warn that control reaches the end
  72                  * of this function without returning a value because
  73                  * die_if_kernel() is marked with attribute 'noreturn'.
  74                  * Alas, some versions do...
  75                  */
  76
  77                 return 0;
  78         }
  79 }
  80
  81 static inline int decode_asi(unsigned int insn, struct pt_regs *regs)
  82 {
  83         if (insn & 0x800000) {
  84                 if (insn & 0x2000)
  85                         return (unsigned char)(regs->tstate >> 24);     /* %asi */
  86                 else
  87                         return (unsigned char)(insn >> 5);              /* imm_asi */
  88         } else
  89                 return ASI_P;
  90 }
  91
  92 /* 0x400000 = signed, 0 = unsigned */
  93 static inline int decode_signedness(unsigned int insn)
  94 {
  95         return (insn & 0x400000);
  96 }
  97
  98 static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
  99                                        unsigned int rd, int from_kernel)
 100 {
 101         if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
 102                 if (from_kernel != 0)
 103                         __asm__ __volatile__("flushw");
 104                 else
 105                         flushw_user();
 106         }
 107 }
 108
 109 static inline long sign_extend_imm13(long imm)
 110 {
 111         return imm << 51 >> 51;
 112 }
 113
 114 static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
 115 {
 116         unsigned long value, fp;
 117
 118         if (reg < 16)
 119                 return (!reg ? 0 : regs->u_regs[reg]);
 120
 121         fp = regs->u_regs[UREG_FP];
 122
 123         if (regs->tstate & TSTATE_PRIV) {
 124                 struct reg_window *win;
 125                 win = (struct reg_window *)(fp + STACK_BIAS);
 126                 value = win->locals[reg - 16];
 127         } else if (!test_thread_64bit_stack(fp)) {
 128                 struct reg_window32 __user *win32;
 129                 win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 130                 get_user(value, &win32->locals[reg - 16]);
 131         } else {
 132                 struct reg_window __user *win;
 133                 win = (struct reg_window __user *)(fp + STACK_BIAS);
 134                 get_user(value, &win->locals[reg - 16]);
 135         }
 136         return value;
 137 }
 138
 139 static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
 140 {
 141         unsigned long fp;
 142
 143         if (reg < 16)
 144                 return &regs->u_regs[reg];
 145
 146         fp = regs->u_regs[UREG_FP];
 147
 148         if (regs->tstate & TSTATE_PRIV) {
 149                 struct reg_window *win;
 150                 win = (struct reg_window *)(fp + STACK_BIAS);
 151                 return &win->locals[reg - 16];
 152         } else if (!test_thread_64bit_stack(fp)) {
 153                 struct reg_window32 *win32;
 154                 win32 = (struct reg_window32 *)((unsigned long)((u32)fp));
 155                 return (unsigned long *)&win32->locals[reg - 16];
 156         } else {
 157                 struct reg_window *win;
 158                 win = (struct reg_window *)(fp + STACK_BIAS);
 159                 return &win->locals[reg - 16];
 160         }
 161 }
 162
 163 unsigned long compute_effective_address(struct pt_regs *regs,
 164                                         unsigned int insn, unsigned int rd)
 165 {
 166         unsigned int rs1 = (insn >> 14) & 0x1f;
 167         unsigned int rs2 = insn & 0x1f;
 168         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 169
 170         if (insn & 0x2000) {
 171                 maybe_flush_windows(rs1, 0, rd, from_kernel);
 172                 return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
 173         } else {
 174                 maybe_flush_windows(rs1, rs2, rd, from_kernel);
 175                 return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
 176         }
 177 }
 178
 179 /* This is just to make gcc think die_if_kernel does return... */
 180 static void __used unaligned_panic(char *str, struct pt_regs *regs)
 181 {
 182         die_if_kernel(str, regs);
 183 }
 184
 185 extern int do_int_load(unsigned long *dest_reg, int size,
 186                        unsigned long *saddr, int is_signed, int asi);
 187
 188 extern int __do_int_store(unsigned long *dst_addr, int size,
 189                           unsigned long src_val, int asi);
 190
 191 static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
 192                                struct pt_regs *regs, int asi, int orig_asi)
 193 {
 194         unsigned long zero = 0;
 195         unsigned long *src_val_p = &zero;
 196         unsigned long src_val;
 197
 198         if (size == 16) {
 199                 size = 8;
 200                 zero = (((long)(reg_num ?
 201                         (unsigned)fetch_reg(reg_num, regs) : 0)) << 32) |
 202                         (unsigned)fetch_reg(reg_num + 1, regs);
 203         } else if (reg_num) {
 204                 src_val_p = fetch_reg_addr(reg_num, regs);
 205         }
 206         src_val = *src_val_p;
 207         if (unlikely(asi != orig_asi)) {
 208                 switch (size) {
 209                 case 2:
 210                         src_val = swab16(src_val);
 211                         break;
 212                 case 4:
 213                         src_val = swab32(src_val);
 214                         break;
 215                 case 8:
 216                         src_val = swab64(src_val);
 217                         break;
 218                 case 16:
 219                 default:
 220                         BUG();
 221                         break;
 222                 }
 223         }
 224         return __do_int_store(dst_addr, size, src_val, asi);
 225 }
 226
 227 static inline void advance(struct pt_regs *regs)
 228 {
 229         regs->tpc   = regs->tnpc;
 230         regs->tnpc += 4;
 231         if (test_thread_flag(TIF_32BIT)) {
 232                 regs->tpc &= 0xffffffff;
 233                 regs->tnpc &= 0xffffffff;
 234         }
 235 }
 236
 237 static inline int floating_point_load_or_store_p(unsigned int insn)
 238 {
 239         return (insn >> 24) & 1;
 240 }
 241
 242 static inline int ok_for_kernel(unsigned int insn)
 243 {
 244         return !floating_point_load_or_store_p(insn);
 245 }
 246
 247 static void kernel_mna_trap_fault(int fixup_tstate_asi)
 248 {
 249         struct pt_regs *regs = current_thread_info()->kern_una_regs;
 250         unsigned int insn = current_thread_info()->kern_una_insn;
 251         const struct exception_table_entry *entry;
 252
 253         entry = search_exception_tables(regs->tpc);
 254         if (!entry) {
 255                 unsigned long address;
 256
 257                 address = compute_effective_address(regs, insn,
 258                                                     ((insn >> 25) & 0x1f));
 259                 if (address < PAGE_SIZE) {
 260                         printk(KERN_ALERT "Unable to handle kernel NULL "
 261                                "pointer dereference in mna handler");
 262                 } else
 263                         printk(KERN_ALERT "Unable to handle kernel paging "
 264                                "request in mna handler");
 265                 printk(KERN_ALERT " at virtual address %016lx\n",address);
 266                 printk(KERN_ALERT "current->{active_,}mm->context = %016lx\n",
 267                         (current->mm ? CTX_HWBITS(current->mm->context) :
 268                         CTX_HWBITS(current->active_mm->context)));
 269                 printk(KERN_ALERT "current->{active_,}mm->pgd = %016lx\n",
 270                         (current->mm ? (unsigned long) current->mm->pgd :
 271                         (unsigned long) current->active_mm->pgd));
 272                 die_if_kernel("Oops", regs);
 273                 /* Not reached */
 274         }
 275         regs->tpc = entry->fixup;
 276         regs->tnpc = regs->tpc + 4;
 277
 278         if (fixup_tstate_asi) {
 279                 regs->tstate &= ~TSTATE_ASI;
 280                 regs->tstate |= (ASI_AIUS << 24UL);
 281         }
 282 }
 283
 284 static void log_unaligned(struct pt_regs *regs)
 285 {
 286         static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
 287
 288         if (__ratelimit(&ratelimit)) {
 289                 printk("Kernel unaligned access at TPC[%lx] %pS\n",
 290                        regs->tpc, (void *) regs->tpc);
 291         }
 292 }
 293
 294 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 295 {
 296         enum direction dir = decode_direction(insn);
 297         int size = decode_access_size(regs, insn);
 298         int orig_asi, asi;
 299
 300         current_thread_info()->kern_una_regs = regs;
 301         current_thread_info()->kern_una_insn = insn;
 302
 303         orig_asi = asi = decode_asi(insn, regs);
 304
 305         /* If this is a {get,put}_user() on an unaligned userspace pointer,
 306          * just signal a fault and do not log the event.
 307          */
 308         if (asi == ASI_AIUS) {
 309                 kernel_mna_trap_fault(0);
 310                 return;
 311         }
 312
 313         log_unaligned(regs);
 314
 315         if (!ok_for_kernel(insn) || dir == both) {
 316                 printk("Unsupported unaligned load/store trap for kernel "
 317                        "at <%016lx>.\n", regs->tpc);
 318                 unaligned_panic("Kernel does fpu/atomic "
 319                                 "unaligned load/store.", regs);
 320
 321                 kernel_mna_trap_fault(0);
 322         } else {
 323                 unsigned long addr, *reg_addr;
 324                 int err;
 325
 326                 addr = compute_effective_address(regs, insn,
 327                                                  ((insn >> 25) & 0x1f));
 328                 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
 329                 switch (asi) {
 330                 case ASI_NL:
 331                 case ASI_AIUPL:
 332                 case ASI_AIUSL:
 333                 case ASI_PL:
 334                 case ASI_SL:
 335                 case ASI_PNFL:
 336                 case ASI_SNFL:
 337                         asi &= ~0x08;
 338                         break;
 339                 }
 340                 switch (dir) {
 341                 case load:
 342                         reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
 343                         err = do_int_load(reg_addr, size,
 344                                           (unsigned long *) addr,
 345                                           decode_signedness(insn), asi);
 346                         if (likely(!err) && unlikely(asi != orig_asi)) {
 347                                 unsigned long val_in = *reg_addr;
 348                                 switch (size) {
 349                                 case 2:
 350                                         val_in = swab16(val_in);
 351                                         break;
 352                                 case 4:
 353                                         val_in = swab32(val_in);
 354                                         break;
 355                                 case 8:
 356                                         val_in = swab64(val_in);
 357                                         break;
 358                                 case 16:
 359                                 default:
 360                                         BUG();
 361                                         break;
 362                                 }
 363                                 *reg_addr = val_in;
 364                         }
 365                         break;
 366
 367                 case store:
 368                         err = do_int_store(((insn>>25)&0x1f), size,
 369                                            (unsigned long *) addr, regs,
 370                                            asi, orig_asi);
 371                         break;
 372
 373                 default:
 374                         panic("Impossible kernel unaligned trap.");
 375                         /* Not reached... */
 376                 }
 377                 if (unlikely(err))
 378                         kernel_mna_trap_fault(1);
 379                 else
 380                         advance(regs);
 381         }
 382 }
 383
 384 int handle_popc(u32 insn, struct pt_regs *regs)
 385 {
 386         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 387         int ret, rd = ((insn >> 25) & 0x1f);
 388         u64 value;
 389
 390         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 391         if (insn & 0x2000) {
 392                 maybe_flush_windows(0, 0, rd, from_kernel);
 393                 value = sign_extend_imm13(insn);
 394         } else {
 395                 maybe_flush_windows(0, insn & 0x1f, rd, from_kernel);
 396                 value = fetch_reg(insn & 0x1f, regs);
 397         }
 398         ret = hweight64(value);
 399         if (rd < 16) {
 400                 if (rd)
 401                         regs->u_regs[rd] = ret;
 402         } else {
 403                 unsigned long fp = regs->u_regs[UREG_FP];
 404
 405                 if (!test_thread_64bit_stack(fp)) {
 406                         struct reg_window32 __user *win32;
 407                         win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 408                         put_user(ret, &win32->locals[rd - 16]);
 409                 } else {
 410                         struct reg_window __user *win;
 411                         win = (struct reg_window __user *)(fp + STACK_BIAS);
 412                         put_user(ret, &win->locals[rd - 16]);
 413                 }
 414         }
 415         advance(regs);
 416         return 1;
 417 }
 418
 419 extern void do_fpother(struct pt_regs *regs);
 420 extern void do_privact(struct pt_regs *regs);
 421 extern void spitfire_data_access_exception(struct pt_regs *regs,
 422                                            unsigned long sfsr,
 423                                            unsigned long sfar);
 424 extern void sun4v_data_access_exception(struct pt_regs *regs,
 425                                         unsigned long addr,
 426                                         unsigned long type_ctx);
 427
 428 int handle_ldf_stq(u32 insn, struct pt_regs *regs)
 429 {
 430         unsigned long addr = compute_effective_address(regs, insn, 0);
 431         int freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 432         struct fpustate *f = FPUSTATE;
 433         int asi = decode_asi(insn, regs);
 434         int flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 435
 436         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 437
 438         save_and_clear_fpu();
 439         current_thread_info()->xfsr[0] &= ~0x1c000;
 440         if (freg & 3) {
 441                 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 442                 do_fpother(regs);
 443                 return 0;
 444         }
 445         if (insn & 0x200000) {
 446                 /* STQ */
 447                 u64 first = 0, second = 0;
 448
 449                 if (current_thread_info()->fpsaved[0] & flag) {
 450                         first = *(u64 *)&f->regs[freg];
 451                         second = *(u64 *)&f->regs[freg+2];
 452                 }
 453                 if (asi < 0x80) {
 454                         do_privact(regs);
 455                         return 1;
 456                 }
 457                 switch (asi) {
 458                 case ASI_P:
 459                 case ASI_S: break;
 460                 case ASI_PL:
 461                 case ASI_SL:
 462                         {
 463                                 /* Need to convert endians */
 464                                 u64 tmp = __swab64p(&first);
 465
 466                                 first = __swab64p(&second);
 467                                 second = tmp;
 468                                 break;
 469                         }
 470                 default:
 471                         if (tlb_type == hypervisor)
 472                                 sun4v_data_access_exception(regs, addr, 0);
 473                         else
 474                                 spitfire_data_access_exception(regs, 0, addr);
 475                         return 1;
 476                 }
 477                 if (put_user (first >> 32, (u32 __user *)addr) ||
 478                     __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
 479                     __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
 480                     __put_user ((u32)second, (u32 __user *)(addr + 12))) {
 481                         if (tlb_type == hypervisor)
 482                                 sun4v_data_access_exception(regs, addr, 0);
 483                         else
 484                                 spitfire_data_access_exception(regs, 0, addr);
 485                         return 1;
 486                 }
 487         } else {
 488                 /* LDF, LDDF, LDQF */
 489                 u32 data[4] __attribute__ ((aligned(8)));
 490                 int size, i;
 491                 int err;
 492
 493                 if (asi < 0x80) {
 494                         do_privact(regs);
 495                         return 1;
 496                 } else if (asi > ASI_SNFL) {
 497                         if (tlb_type == hypervisor)
 498                                 sun4v_data_access_exception(regs, addr, 0);
 499                         else
 500                                 spitfire_data_access_exception(regs, 0, addr);
 501                         return 1;
 502                 }
 503                 switch (insn & 0x180000) {
 504                 case 0x000000: size = 1; break;
 505                 case 0x100000: size = 4; break;
 506                 default: size = 2; break;
 507                 }
 508                 for (i = 0; i < size; i++)
 509                         data[i] = 0;
 510
 511                 err = get_user (data[0], (u32 __user *) addr);
 512                 if (!err) {
 513                         for (i = 1; i < size; i++)
 514                                 err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
 515                 }
 516                 if (err && !(asi & 0x2 /* NF */)) {
 517                         if (tlb_type == hypervisor)
 518                                 sun4v_data_access_exception(regs, addr, 0);
 519                         else
 520                                 spitfire_data_access_exception(regs, 0, addr);
 521                         return 1;
 522                 }
 523                 if (asi & 0x8) /* Little */ {
 524                         u64 tmp;
 525
 526                         switch (size) {
 527                         case 1: data[0] = le32_to_cpup(data + 0); break;
 528                         default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
 529                                 break;
 530                         case 4: tmp = le64_to_cpup((u64 *)(data + 0));
 531                                 *(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
 532                                 *(u64 *)(data + 2) = tmp;
 533                                 break;
 534                         }
 535                 }
 536                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 537                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 538                         current_thread_info()->gsr[0] = 0;
 539                 }
 540                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 541                         if (freg < 32)
 542                                 memset(f->regs, 0, 32*sizeof(u32));
 543                         else
 544                                 memset(f->regs+32, 0, 32*sizeof(u32));
 545                 }
 546                 memcpy(f->regs + freg, data, size * 4);
 547                 current_thread_info()->fpsaved[0] |= flag;
 548         }
 549         advance(regs);
 550         return 1;
 551 }
 552
 553 void handle_ld_nf(u32 insn, struct pt_regs *regs)
 554 {
 555         int rd = ((insn >> 25) & 0x1f);
 556         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 557         unsigned long *reg;
 558
 559         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 560
 561         maybe_flush_windows(0, 0, rd, from_kernel);
 562         reg = fetch_reg_addr(rd, regs);
 563         if (from_kernel || rd < 16) {
 564                 reg[0] = 0;
 565                 if ((insn & 0x780000) == 0x180000)
 566                         reg[1] = 0;
 567         } else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) {
 568                 put_user(0, (int __user *) reg);
 569                 if ((insn & 0x780000) == 0x180000)
 570                         put_user(0, ((int __user *) reg) + 1);
 571         } else {
 572                 put_user(0, (unsigned long __user *) reg);
 573                 if ((insn & 0x780000) == 0x180000)
 574                         put_user(0, (unsigned long __user *) reg + 1);
 575         }
 576         advance(regs);
 577 }
 578
 579 void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 580 {
 581         unsigned long pc = regs->tpc;
 582         unsigned long tstate = regs->tstate;
 583         u32 insn;
 584         u64 value;
 585         u8 freg;
 586         int flag;
 587         struct fpustate *f = FPUSTATE;
 588
 589         if (tstate & TSTATE_PRIV)
 590                 die_if_kernel("lddfmna from kernel", regs);
 591         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 592         if (test_thread_flag(TIF_32BIT))
 593                 pc = (u32)pc;
 594         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 595                 int asi = decode_asi(insn, regs);
 596                 u32 first, second;
 597                 int err;
 598
 599                 if ((asi > ASI_SNFL) ||
 600                     (asi < ASI_P))
 601                         goto daex;
 602                 first = second = 0;
 603                 err = get_user(first, (u32 __user *)sfar);
 604                 if (!err)
 605                         err = get_user(second, (u32 __user *)(sfar + 4));
 606                 if (err) {
 607                         if (!(asi & 0x2))
 608                                 goto daex;
 609                         first = second = 0;
 610                 }
 611                 save_and_clear_fpu();
 612                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 613                 value = (((u64)first) << 32) | second;
 614                 if (asi & 0x8) /* Little */
 615                         value = __swab64p(&value);
 616                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 617                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 618                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 619                         current_thread_info()->gsr[0] = 0;
 620                 }
 621                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 622                         if (freg < 32)
 623                                 memset(f->regs, 0, 32*sizeof(u32));
 624                         else
 625                                 memset(f->regs+32, 0, 32*sizeof(u32));
 626                 }
 627                 *(u64 *)(f->regs + freg) = value;
 628                 current_thread_info()->fpsaved[0] |= flag;
 629         } else {
 630 daex:
 631                 if (tlb_type == hypervisor)
 632                         sun4v_data_access_exception(regs, sfar, sfsr);
 633                 else
 634                         spitfire_data_access_exception(regs, sfsr, sfar);
 635                 return;
 636         }
 637         advance(regs);
 638 }
 639
 640 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 641 {
 642         unsigned long pc = regs->tpc;
 643         unsigned long tstate = regs->tstate;
 644         u32 insn;
 645         u64 value;
 646         u8 freg;
 647         int flag;
 648         struct fpustate *f = FPUSTATE;
 649
 650         if (tstate & TSTATE_PRIV)
 651                 die_if_kernel("stdfmna from kernel", regs);
 652         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 653         if (test_thread_flag(TIF_32BIT))
 654                 pc = (u32)pc;
 655         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 656                 int asi = decode_asi(insn, regs);
 657                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 658                 value = 0;
 659                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 660                 if ((asi > ASI_SNFL) ||
 661                     (asi < ASI_P))
 662                         goto daex;
 663                 save_and_clear_fpu();
 664                 if (current_thread_info()->fpsaved[0] & flag)
 665                         value = *(u64 *)&f->regs[freg];
 666                 switch (asi) {
 667                 case ASI_P:
 668                 case ASI_S: break;
 669                 case ASI_PL:
 670                 case ASI_SL:
 671                         value = __swab64p(&value); break;
 672                 default: goto daex;
 673                 }
 674                 if (put_user (value >> 32, (u32 __user *) sfar) ||
 675                     __put_user ((u32)value, (u32 __user *)(sfar + 4)))
 676                         goto daex;
 677         } else {
 678 daex:
 679                 if (tlb_type == hypervisor)
 680                         sun4v_data_access_exception(regs, sfar, sfsr);
 681                 else
 682                         spitfire_data_access_exception(regs, sfsr, sfar);
 683                 return;
 684         }
 685         advance(regs);
 686 }