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 <linux/context_tracking.h>
  25 #include <asm/fpumacro.h>
  26 #include <asm/cacheflush.h>
  27 #include <asm/setup.h>
  28
  29 #include "entry.h"
  30 #include "kernel.h"
  31
  32 enum direction {
  33         load,    /* ld, ldd, ldh, ldsh */
  34         store,   /* st, std, sth, stsh */
  35         both,    /* Swap, ldstub, cas, ... */
  36         fpld,
  37         fpst,
  38         invalid,
  39 };
  40
  41 static inline enum direction decode_direction(unsigned int insn)
  42 {
  43         unsigned long tmp = (insn >> 21) & 1;
  44
  45         if (!tmp)
  46                 return load;
  47         else {
  48                 switch ((insn>>19)&0xf) {
  49                 case 15: /* swap* */
  50                         return both;
  51                 default:
  52                         return store;
  53                 }
  54         }
  55 }
  56
  57 /* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
  58 static inline int decode_access_size(struct pt_regs *regs, unsigned int insn)
  59 {
  60         unsigned int tmp;
  61
  62         tmp = ((insn >> 19) & 0xf);
  63         if (tmp == 11 || tmp == 14) /* ldx/stx */
  64                 return 8;
  65         tmp &= 3;
  66         if (!tmp)
  67                 return 4;
  68         else if (tmp == 3)
  69                 return 16;      /* ldd/std - Although it is actually 8 */
  70         else if (tmp == 2)
  71                 return 2;
  72         else {
  73                 printk("Impossible unaligned trap. insn=%08x\n", insn);
  74                 die_if_kernel("Byte sized unaligned access?!?!", regs);
  75
  76                 /* GCC should never warn that control reaches the end
  77                  * of this function without returning a value because
  78                  * die_if_kernel() is marked with attribute 'noreturn'.
  79                  * Alas, some versions do...
  80                  */
  81
  82                 return 0;
  83         }
  84 }
  85
  86 static inline int decode_asi(unsigned int insn, struct pt_regs *regs)
  87 {
  88         if (insn & 0x800000) {
  89                 if (insn & 0x2000)
  90                         return (unsigned char)(regs->tstate >> 24);     /* %asi */
  91                 else
  92                         return (unsigned char)(insn >> 5);              /* imm_asi */
  93         } else
  94                 return ASI_P;
  95 }
  96
  97 /* 0x400000 = signed, 0 = unsigned */
  98 static inline int decode_signedness(unsigned int insn)
  99 {
 100         return (insn & 0x400000);
 101 }
 102
 103 static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
 104                                        unsigned int rd, int from_kernel)
 105 {
 106         if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
 107                 if (from_kernel != 0)
 108                         __asm__ __volatile__("flushw");
 109                 else
 110                         flushw_user();
 111         }
 112 }
 113
 114 static inline long sign_extend_imm13(long imm)
 115 {
 116         return imm << 51 >> 51;
 117 }
 118
 119 static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
 120 {
 121         unsigned long value, fp;
 122
 123         if (reg < 16)
 124                 return (!reg ? 0 : regs->u_regs[reg]);
 125
 126         fp = regs->u_regs[UREG_FP];
 127
 128         if (regs->tstate & TSTATE_PRIV) {
 129                 struct reg_window *win;
 130                 win = (struct reg_window *)(fp + STACK_BIAS);
 131                 value = win->locals[reg - 16];
 132         } else if (!test_thread_64bit_stack(fp)) {
 133                 struct reg_window32 __user *win32;
 134                 win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 135                 get_user(value, &win32->locals[reg - 16]);
 136         } else {
 137                 struct reg_window __user *win;
 138                 win = (struct reg_window __user *)(fp + STACK_BIAS);
 139                 get_user(value, &win->locals[reg - 16]);
 140         }
 141         return value;
 142 }
 143
 144 static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
 145 {
 146         unsigned long fp;
 147
 148         if (reg < 16)
 149                 return &regs->u_regs[reg];
 150
 151         fp = regs->u_regs[UREG_FP];
 152
 153         if (regs->tstate & TSTATE_PRIV) {
 154                 struct reg_window *win;
 155                 win = (struct reg_window *)(fp + STACK_BIAS);
 156                 return &win->locals[reg - 16];
 157         } else if (!test_thread_64bit_stack(fp)) {
 158                 struct reg_window32 *win32;
 159                 win32 = (struct reg_window32 *)((unsigned long)((u32)fp));
 160                 return (unsigned long *)&win32->locals[reg - 16];
 161         } else {
 162                 struct reg_window *win;
 163                 win = (struct reg_window *)(fp + STACK_BIAS);
 164                 return &win->locals[reg - 16];
 165         }
 166 }
 167
 168 unsigned long compute_effective_address(struct pt_regs *regs,
 169                                         unsigned int insn, unsigned int rd)
 170 {
 171         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 172         unsigned int rs1 = (insn >> 14) & 0x1f;
 173         unsigned int rs2 = insn & 0x1f;
 174         unsigned long addr;
 175
 176         if (insn & 0x2000) {
 177                 maybe_flush_windows(rs1, 0, rd, from_kernel);
 178                 addr = (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
 179         } else {
 180                 maybe_flush_windows(rs1, rs2, rd, from_kernel);
 181                 addr = (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
 182         }
 183
 184         if (!from_kernel && test_thread_flag(TIF_32BIT))
 185                 addr &= 0xffffffff;
 186
 187         return addr;
 188 }
 189
 190 /* This is just to make gcc think die_if_kernel does return... */
 191 static void __used unaligned_panic(char *str, struct pt_regs *regs)
 192 {
 193         die_if_kernel(str, regs);
 194 }
 195
 196 extern int do_int_load(unsigned long *dest_reg, int size,
 197                        unsigned long *saddr, int is_signed, int asi);
 198
 199 extern int __do_int_store(unsigned long *dst_addr, int size,
 200                           unsigned long src_val, int asi);
 201
 202 static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
 203                                struct pt_regs *regs, int asi, int orig_asi)
 204 {
 205         unsigned long zero = 0;
 206         unsigned long *src_val_p = &zero;
 207         unsigned long src_val;
 208
 209         if (size == 16) {
 210                 size = 8;
 211                 zero = (((long)(reg_num ?
 212                         (unsigned)fetch_reg(reg_num, regs) : 0)) << 32) |
 213                         (unsigned)fetch_reg(reg_num + 1, regs);
 214         } else if (reg_num) {
 215                 src_val_p = fetch_reg_addr(reg_num, regs);
 216         }
 217         src_val = *src_val_p;
 218         if (unlikely(asi != orig_asi)) {
 219                 switch (size) {
 220                 case 2:
 221                         src_val = swab16(src_val);
 222                         break;
 223                 case 4:
 224                         src_val = swab32(src_val);
 225                         break;
 226                 case 8:
 227                         src_val = swab64(src_val);
 228                         break;
 229                 case 16:
 230                 default:
 231                         BUG();
 232                         break;
 233                 }
 234         }
 235         return __do_int_store(dst_addr, size, src_val, asi);
 236 }
 237
 238 static inline void advance(struct pt_regs *regs)
 239 {
 240         regs->tpc   = regs->tnpc;
 241         regs->tnpc += 4;
 242         if (test_thread_flag(TIF_32BIT)) {
 243                 regs->tpc &= 0xffffffff;
 244                 regs->tnpc &= 0xffffffff;
 245         }
 246 }
 247
 248 static inline int floating_point_load_or_store_p(unsigned int insn)
 249 {
 250         return (insn >> 24) & 1;
 251 }
 252
 253 static inline int ok_for_kernel(unsigned int insn)
 254 {
 255         return !floating_point_load_or_store_p(insn);
 256 }
 257
 258 static void kernel_mna_trap_fault(int fixup_tstate_asi)
 259 {
 260         struct pt_regs *regs = current_thread_info()->kern_una_regs;
 261         unsigned int insn = current_thread_info()->kern_una_insn;
 262         const struct exception_table_entry *entry;
 263
 264         entry = search_exception_tables(regs->tpc);
 265         if (!entry) {
 266                 unsigned long address;
 267
 268                 address = compute_effective_address(regs, insn,
 269                                                     ((insn >> 25) & 0x1f));
 270                 if (address < PAGE_SIZE) {
 271                         printk(KERN_ALERT "Unable to handle kernel NULL "
 272                                "pointer dereference in mna handler");
 273                 } else
 274                         printk(KERN_ALERT "Unable to handle kernel paging "
 275                                "request in mna handler");
 276                 printk(KERN_ALERT " at virtual address %016lx\n",address);
 277                 printk(KERN_ALERT "current->{active_,}mm->context = %016lx\n",
 278                         (current->mm ? CTX_HWBITS(current->mm->context) :
 279                         CTX_HWBITS(current->active_mm->context)));
 280                 printk(KERN_ALERT "current->{active_,}mm->pgd = %016lx\n",
 281                         (current->mm ? (unsigned long) current->mm->pgd :
 282                         (unsigned long) current->active_mm->pgd));
 283                 die_if_kernel("Oops", regs);
 284                 /* Not reached */
 285         }
 286         regs->tpc = entry->fixup;
 287         regs->tnpc = regs->tpc + 4;
 288
 289         if (fixup_tstate_asi) {
 290                 regs->tstate &= ~TSTATE_ASI;
 291                 regs->tstate |= (ASI_AIUS << 24UL);
 292         }
 293 }
 294
 295 static void log_unaligned(struct pt_regs *regs)
 296 {
 297         static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
 298
 299         if (__ratelimit(&ratelimit)) {
 300                 printk("Kernel unaligned access at TPC[%lx] %pS\n",
 301                        regs->tpc, (void *) regs->tpc);
 302         }
 303 }
 304
 305 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 306 {
 307         enum direction dir = decode_direction(insn);
 308         int size = decode_access_size(regs, insn);
 309         int orig_asi, asi;
 310
 311         current_thread_info()->kern_una_regs = regs;
 312         current_thread_info()->kern_una_insn = insn;
 313
 314         orig_asi = asi = decode_asi(insn, regs);
 315
 316         /* If this is a {get,put}_user() on an unaligned userspace pointer,
 317          * just signal a fault and do not log the event.
 318          */
 319         if (asi == ASI_AIUS) {
 320                 kernel_mna_trap_fault(0);
 321                 return;
 322         }
 323
 324         log_unaligned(regs);
 325
 326         if (!ok_for_kernel(insn) || dir == both) {
 327                 printk("Unsupported unaligned load/store trap for kernel "
 328                        "at <%016lx>.\n", regs->tpc);
 329                 unaligned_panic("Kernel does fpu/atomic "
 330                                 "unaligned load/store.", regs);
 331
 332                 kernel_mna_trap_fault(0);
 333         } else {
 334                 unsigned long addr, *reg_addr;
 335                 int err;
 336
 337                 addr = compute_effective_address(regs, insn,
 338                                                  ((insn >> 25) & 0x1f));
 339                 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
 340                 switch (asi) {
 341                 case ASI_NL:
 342                 case ASI_AIUPL:
 343                 case ASI_AIUSL:
 344                 case ASI_PL:
 345                 case ASI_SL:
 346                 case ASI_PNFL:
 347                 case ASI_SNFL:
 348                         asi &= ~0x08;
 349                         break;
 350                 }
 351                 switch (dir) {
 352                 case load:
 353                         reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
 354                         err = do_int_load(reg_addr, size,
 355                                           (unsigned long *) addr,
 356                                           decode_signedness(insn), asi);
 357                         if (likely(!err) && unlikely(asi != orig_asi)) {
 358                                 unsigned long val_in = *reg_addr;
 359                                 switch (size) {
 360                                 case 2:
 361                                         val_in = swab16(val_in);
 362                                         break;
 363                                 case 4:
 364                                         val_in = swab32(val_in);
 365                                         break;
 366                                 case 8:
 367                                         val_in = swab64(val_in);
 368                                         break;
 369                                 case 16:
 370                                 default:
 371                                         BUG();
 372                                         break;
 373                                 }
 374                                 *reg_addr = val_in;
 375                         }
 376                         break;
 377
 378                 case store:
 379                         err = do_int_store(((insn>>25)&0x1f), size,
 380                                            (unsigned long *) addr, regs,
 381                                            asi, orig_asi);
 382                         break;
 383
 384                 default:
 385                         panic("Impossible kernel unaligned trap.");
 386                         /* Not reached... */
 387                 }
 388                 if (unlikely(err))
 389                         kernel_mna_trap_fault(1);
 390                 else
 391                         advance(regs);
 392         }
 393 }
 394
 395 int handle_popc(u32 insn, struct pt_regs *regs)
 396 {
 397         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 398         int ret, rd = ((insn >> 25) & 0x1f);
 399         u64 value;
 400
 401         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 402         if (insn & 0x2000) {
 403                 maybe_flush_windows(0, 0, rd, from_kernel);
 404                 value = sign_extend_imm13(insn);
 405         } else {
 406                 maybe_flush_windows(0, insn & 0x1f, rd, from_kernel);
 407                 value = fetch_reg(insn & 0x1f, regs);
 408         }
 409         ret = hweight64(value);
 410         if (rd < 16) {
 411                 if (rd)
 412                         regs->u_regs[rd] = ret;
 413         } else {
 414                 unsigned long fp = regs->u_regs[UREG_FP];
 415
 416                 if (!test_thread_64bit_stack(fp)) {
 417                         struct reg_window32 __user *win32;
 418                         win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 419                         put_user(ret, &win32->locals[rd - 16]);
 420                 } else {
 421                         struct reg_window __user *win;
 422                         win = (struct reg_window __user *)(fp + STACK_BIAS);
 423                         put_user(ret, &win->locals[rd - 16]);
 424                 }
 425         }
 426         advance(regs);
 427         return 1;
 428 }
 429
 430 extern void do_fpother(struct pt_regs *regs);
 431 extern void do_privact(struct pt_regs *regs);
 432 extern void sun4v_data_access_exception(struct pt_regs *regs,
 433                                         unsigned long addr,
 434                                         unsigned long type_ctx);
 435
 436 int handle_ldf_stq(u32 insn, struct pt_regs *regs)
 437 {
 438         unsigned long addr = compute_effective_address(regs, insn, 0);
 439         int freg;
 440         struct fpustate *f = FPUSTATE;
 441         int asi = decode_asi(insn, regs);
 442         int flag;
 443
 444         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 445
 446         save_and_clear_fpu();
 447         current_thread_info()->xfsr[0] &= ~0x1c000;
 448         if (insn & 0x200000) {
 449                 /* STQ */
 450                 u64 first = 0, second = 0;
 451
 452                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 453                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 454                 if (freg & 3) {
 455                         current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 456                         do_fpother(regs);
 457                         return 0;
 458                 }
 459                 if (current_thread_info()->fpsaved[0] & flag) {
 460                         first = *(u64 *)&f->regs[freg];
 461                         second = *(u64 *)&f->regs[freg+2];
 462                 }
 463                 if (asi < 0x80) {
 464                         do_privact(regs);
 465                         return 1;
 466                 }
 467                 switch (asi) {
 468                 case ASI_P:
 469                 case ASI_S: break;
 470                 case ASI_PL:
 471                 case ASI_SL:
 472                         {
 473                                 /* Need to convert endians */
 474                                 u64 tmp = __swab64p(&first);
 475
 476                                 first = __swab64p(&second);
 477                                 second = tmp;
 478                                 break;
 479                         }
 480                 default:
 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                 if (put_user (first >> 32, (u32 __user *)addr) ||
 488                     __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
 489                     __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
 490                     __put_user ((u32)second, (u32 __user *)(addr + 12))) {
 491                         if (tlb_type == hypervisor)
 492                                 sun4v_data_access_exception(regs, addr, 0);
 493                         else
 494                                 spitfire_data_access_exception(regs, 0, addr);
 495                         return 1;
 496                 }
 497         } else {
 498                 /* LDF, LDDF, LDQF */
 499                 u32 data[4] __attribute__ ((aligned(8)));
 500                 int size, i;
 501                 int err;
 502
 503                 if (asi < 0x80) {
 504                         do_privact(regs);
 505                         return 1;
 506                 } else if (asi > ASI_SNFL) {
 507                         if (tlb_type == hypervisor)
 508                                 sun4v_data_access_exception(regs, addr, 0);
 509                         else
 510                                 spitfire_data_access_exception(regs, 0, addr);
 511                         return 1;
 512                 }
 513                 switch (insn & 0x180000) {
 514                 case 0x000000: size = 1; break;
 515                 case 0x100000: size = 4; break;
 516                 default: size = 2; break;
 517                 }
 518                 if (size == 1)
 519                         freg = (insn >> 25) & 0x1f;
 520                 else
 521                         freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 522                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 523
 524                 for (i = 0; i < size; i++)
 525                         data[i] = 0;
 526
 527                 err = get_user (data[0], (u32 __user *) addr);
 528                 if (!err) {
 529                         for (i = 1; i < size; i++)
 530                                 err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
 531                 }
 532                 if (err && !(asi & 0x2 /* NF */)) {
 533                         if (tlb_type == hypervisor)
 534                                 sun4v_data_access_exception(regs, addr, 0);
 535                         else
 536                                 spitfire_data_access_exception(regs, 0, addr);
 537                         return 1;
 538                 }
 539                 if (asi & 0x8) /* Little */ {
 540                         u64 tmp;
 541
 542                         switch (size) {
 543                         case 1: data[0] = le32_to_cpup(data + 0); break;
 544                         default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
 545                                 break;
 546                         case 4: tmp = le64_to_cpup((u64 *)(data + 0));
 547                                 *(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
 548                                 *(u64 *)(data + 2) = tmp;
 549                                 break;
 550                         }
 551                 }
 552                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 553                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 554                         current_thread_info()->gsr[0] = 0;
 555                 }
 556                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 557                         if (freg < 32)
 558                                 memset(f->regs, 0, 32*sizeof(u32));
 559                         else
 560                                 memset(f->regs+32, 0, 32*sizeof(u32));
 561                 }
 562                 memcpy(f->regs + freg, data, size * 4);
 563                 current_thread_info()->fpsaved[0] |= flag;
 564         }
 565         advance(regs);
 566         return 1;
 567 }
 568
 569 void handle_ld_nf(u32 insn, struct pt_regs *regs)
 570 {
 571         int rd = ((insn >> 25) & 0x1f);
 572         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 573         unsigned long *reg;
 574
 575         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 576
 577         maybe_flush_windows(0, 0, rd, from_kernel);
 578         reg = fetch_reg_addr(rd, regs);
 579         if (from_kernel || rd < 16) {
 580                 reg[0] = 0;
 581                 if ((insn & 0x780000) == 0x180000)
 582                         reg[1] = 0;
 583         } else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) {
 584                 put_user(0, (int __user *) reg);
 585                 if ((insn & 0x780000) == 0x180000)
 586                         put_user(0, ((int __user *) reg) + 1);
 587         } else {
 588                 put_user(0, (unsigned long __user *) reg);
 589                 if ((insn & 0x780000) == 0x180000)
 590                         put_user(0, (unsigned long __user *) reg + 1);
 591         }
 592         advance(regs);
 593 }
 594
 595 void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 596 {
 597         enum ctx_state prev_state = exception_enter();
 598         unsigned long pc = regs->tpc;
 599         unsigned long tstate = regs->tstate;
 600         u32 insn;
 601         u64 value;
 602         u8 freg;
 603         int flag;
 604         struct fpustate *f = FPUSTATE;
 605
 606         if (tstate & TSTATE_PRIV)
 607                 die_if_kernel("lddfmna from kernel", regs);
 608         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 609         if (test_thread_flag(TIF_32BIT))
 610                 pc = (u32)pc;
 611         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 612                 int asi = decode_asi(insn, regs);
 613                 u32 first, second;
 614                 int err;
 615
 616                 if ((asi > ASI_SNFL) ||
 617                     (asi < ASI_P))
 618                         goto daex;
 619                 first = second = 0;
 620                 err = get_user(first, (u32 __user *)sfar);
 621                 if (!err)
 622                         err = get_user(second, (u32 __user *)(sfar + 4));
 623                 if (err) {
 624                         if (!(asi & 0x2))
 625                                 goto daex;
 626                         first = second = 0;
 627                 }
 628                 save_and_clear_fpu();
 629                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 630                 value = (((u64)first) << 32) | second;
 631                 if (asi & 0x8) /* Little */
 632                         value = __swab64p(&value);
 633                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 634                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 635                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 636                         current_thread_info()->gsr[0] = 0;
 637                 }
 638                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 639                         if (freg < 32)
 640                                 memset(f->regs, 0, 32*sizeof(u32));
 641                         else
 642                                 memset(f->regs+32, 0, 32*sizeof(u32));
 643                 }
 644                 *(u64 *)(f->regs + freg) = value;
 645                 current_thread_info()->fpsaved[0] |= flag;
 646         } else {
 647 daex:
 648                 if (tlb_type == hypervisor)
 649                         sun4v_data_access_exception(regs, sfar, sfsr);
 650                 else
 651                         spitfire_data_access_exception(regs, sfsr, sfar);
 652                 goto out;
 653         }
 654         advance(regs);
 655 out:
 656         exception_exit(prev_state);
 657 }
 658
 659 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 660 {
 661         enum ctx_state prev_state = exception_enter();
 662         unsigned long pc = regs->tpc;
 663         unsigned long tstate = regs->tstate;
 664         u32 insn;
 665         u64 value;
 666         u8 freg;
 667         int flag;
 668         struct fpustate *f = FPUSTATE;
 669
 670         if (tstate & TSTATE_PRIV)
 671                 die_if_kernel("stdfmna from kernel", regs);
 672         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 673         if (test_thread_flag(TIF_32BIT))
 674                 pc = (u32)pc;
 675         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 676                 int asi = decode_asi(insn, regs);
 677                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 678                 value = 0;
 679                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 680                 if ((asi > ASI_SNFL) ||
 681                     (asi < ASI_P))
 682                         goto daex;
 683                 save_and_clear_fpu();
 684                 if (current_thread_info()->fpsaved[0] & flag)
 685                         value = *(u64 *)&f->regs[freg];
 686                 switch (asi) {
 687                 case ASI_P:
 688                 case ASI_S: break;
 689                 case ASI_PL:
 690                 case ASI_SL:
 691                         value = __swab64p(&value); break;
 692                 default: goto daex;
 693                 }
 694                 if (put_user (value >> 32, (u32 __user *) sfar) ||
 695                     __put_user ((u32)value, (u32 __user *)(sfar + 4)))
 696                         goto daex;
 697         } else {
 698 daex:
 699                 if (tlb_type == hypervisor)
 700                         sun4v_data_access_exception(regs, sfar, sfsr);
 701                 else
 702                         spitfire_data_access_exception(regs, sfsr, sfar);
 703                 goto out;
 704         }
 705         advance(regs);
 706 out:
 707         exception_exit(prev_state);
 708 }