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