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 = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 440         struct fpustate *f = FPUSTATE;
 441         int asi = decode_asi(insn, regs);
 442         int flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 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 (freg & 3) {
 449                 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 450                 do_fpother(regs);
 451                 return 0;
 452         }
 453         if (insn & 0x200000) {
 454                 /* STQ */
 455                 u64 first = 0, second = 0;
 456
 457                 if (current_thread_info()->fpsaved[0] & flag) {
 458                         first = *(u64 *)&f->regs[freg];
 459                         second = *(u64 *)&f->regs[freg+2];
 460                 }
 461                 if (asi < 0x80) {
 462                         do_privact(regs);
 463                         return 1;
 464                 }
 465                 switch (asi) {
 466                 case ASI_P:
 467                 case ASI_S: break;
 468                 case ASI_PL:
 469                 case ASI_SL:
 470                         {
 471                                 /* Need to convert endians */
 472                                 u64 tmp = __swab64p(&first);
 473
 474                                 first = __swab64p(&second);
 475                                 second = tmp;
 476                                 break;
 477                         }
 478                 default:
 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                 if (put_user (first >> 32, (u32 __user *)addr) ||
 486                     __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
 487                     __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
 488                     __put_user ((u32)second, (u32 __user *)(addr + 12))) {
 489                         if (tlb_type == hypervisor)
 490                                 sun4v_data_access_exception(regs, addr, 0);
 491                         else
 492                                 spitfire_data_access_exception(regs, 0, addr);
 493                         return 1;
 494                 }
 495         } else {
 496                 /* LDF, LDDF, LDQF */
 497                 u32 data[4] __attribute__ ((aligned(8)));
 498                 int size, i;
 499                 int err;
 500
 501                 if (asi < 0x80) {
 502                         do_privact(regs);
 503                         return 1;
 504                 } else if (asi > ASI_SNFL) {
 505                         if (tlb_type == hypervisor)
 506                                 sun4v_data_access_exception(regs, addr, 0);
 507                         else
 508                                 spitfire_data_access_exception(regs, 0, addr);
 509                         return 1;
 510                 }
 511                 switch (insn & 0x180000) {
 512                 case 0x000000: size = 1; break;
 513                 case 0x100000: size = 4; break;
 514                 default: size = 2; break;
 515                 }
 516                 for (i = 0; i < size; i++)
 517                         data[i] = 0;
 518
 519                 err = get_user (data[0], (u32 __user *) addr);
 520                 if (!err) {
 521                         for (i = 1; i < size; i++)
 522                                 err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
 523                 }
 524                 if (err && !(asi & 0x2 /* NF */)) {
 525                         if (tlb_type == hypervisor)
 526                                 sun4v_data_access_exception(regs, addr, 0);
 527                         else
 528                                 spitfire_data_access_exception(regs, 0, addr);
 529                         return 1;
 530                 }
 531                 if (asi & 0x8) /* Little */ {
 532                         u64 tmp;
 533
 534                         switch (size) {
 535                         case 1: data[0] = le32_to_cpup(data + 0); break;
 536                         default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
 537                                 break;
 538                         case 4: tmp = le64_to_cpup((u64 *)(data + 0));
 539                                 *(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
 540                                 *(u64 *)(data + 2) = tmp;
 541                                 break;
 542                         }
 543                 }
 544                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 545                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 546                         current_thread_info()->gsr[0] = 0;
 547                 }
 548                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 549                         if (freg < 32)
 550                                 memset(f->regs, 0, 32*sizeof(u32));
 551                         else
 552                                 memset(f->regs+32, 0, 32*sizeof(u32));
 553                 }
 554                 memcpy(f->regs + freg, data, size * 4);
 555                 current_thread_info()->fpsaved[0] |= flag;
 556         }
 557         advance(regs);
 558         return 1;
 559 }
 560
 561 void handle_ld_nf(u32 insn, struct pt_regs *regs)
 562 {
 563         int rd = ((insn >> 25) & 0x1f);
 564         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 565         unsigned long *reg;
 566
 567         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 568
 569         maybe_flush_windows(0, 0, rd, from_kernel);
 570         reg = fetch_reg_addr(rd, regs);
 571         if (from_kernel || rd < 16) {
 572                 reg[0] = 0;
 573                 if ((insn & 0x780000) == 0x180000)
 574                         reg[1] = 0;
 575         } else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) {
 576                 put_user(0, (int __user *) reg);
 577                 if ((insn & 0x780000) == 0x180000)
 578                         put_user(0, ((int __user *) reg) + 1);
 579         } else {
 580                 put_user(0, (unsigned long __user *) reg);
 581                 if ((insn & 0x780000) == 0x180000)
 582                         put_user(0, (unsigned long __user *) reg + 1);
 583         }
 584         advance(regs);
 585 }
 586
 587 void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 588 {
 589         enum ctx_state prev_state = exception_enter();
 590         unsigned long pc = regs->tpc;
 591         unsigned long tstate = regs->tstate;
 592         u32 insn;
 593         u64 value;
 594         u8 freg;
 595         int flag;
 596         struct fpustate *f = FPUSTATE;
 597
 598         if (tstate & TSTATE_PRIV)
 599                 die_if_kernel("lddfmna from kernel", regs);
 600         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 601         if (test_thread_flag(TIF_32BIT))
 602                 pc = (u32)pc;
 603         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 604                 int asi = decode_asi(insn, regs);
 605                 u32 first, second;
 606                 int err;
 607
 608                 if ((asi > ASI_SNFL) ||
 609                     (asi < ASI_P))
 610                         goto daex;
 611                 first = second = 0;
 612                 err = get_user(first, (u32 __user *)sfar);
 613                 if (!err)
 614                         err = get_user(second, (u32 __user *)(sfar + 4));
 615                 if (err) {
 616                         if (!(asi & 0x2))
 617                                 goto daex;
 618                         first = second = 0;
 619                 }
 620                 save_and_clear_fpu();
 621                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 622                 value = (((u64)first) << 32) | second;
 623                 if (asi & 0x8) /* Little */
 624                         value = __swab64p(&value);
 625                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 626                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 627                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 628                         current_thread_info()->gsr[0] = 0;
 629                 }
 630                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 631                         if (freg < 32)
 632                                 memset(f->regs, 0, 32*sizeof(u32));
 633                         else
 634                                 memset(f->regs+32, 0, 32*sizeof(u32));
 635                 }
 636                 *(u64 *)(f->regs + freg) = value;
 637                 current_thread_info()->fpsaved[0] |= flag;
 638         } else {
 639 daex:
 640                 if (tlb_type == hypervisor)
 641                         sun4v_data_access_exception(regs, sfar, sfsr);
 642                 else
 643                         spitfire_data_access_exception(regs, sfsr, sfar);
 644                 goto out;
 645         }
 646         advance(regs);
 647 out:
 648         exception_exit(prev_state);
 649 }
 650
 651 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 652 {
 653         enum ctx_state prev_state = exception_enter();
 654         unsigned long pc = regs->tpc;
 655         unsigned long tstate = regs->tstate;
 656         u32 insn;
 657         u64 value;
 658         u8 freg;
 659         int flag;
 660         struct fpustate *f = FPUSTATE;
 661
 662         if (tstate & TSTATE_PRIV)
 663                 die_if_kernel("stdfmna from kernel", regs);
 664         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 665         if (test_thread_flag(TIF_32BIT))
 666                 pc = (u32)pc;
 667         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 668                 int asi = decode_asi(insn, regs);
 669                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 670                 value = 0;
 671                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 672                 if ((asi > ASI_SNFL) ||
 673                     (asi < ASI_P))
 674                         goto daex;
 675                 save_and_clear_fpu();
 676                 if (current_thread_info()->fpsaved[0] & flag)
 677                         value = *(u64 *)&f->regs[freg];
 678                 switch (asi) {
 679                 case ASI_P:
 680                 case ASI_S: break;
 681                 case ASI_PL:
 682                 case ASI_SL:
 683                         value = __swab64p(&value); break;
 684                 default: goto daex;
 685                 }
 686                 if (put_user (value >> 32, (u32 __user *) sfar) ||
 687                     __put_user ((u32)value, (u32 __user *)(sfar + 4)))
 688                         goto daex;
 689         } else {
 690 daex:
 691                 if (tlb_type == hypervisor)
 692                         sun4v_data_access_exception(regs, sfar, sfsr);
 693                 else
 694                         spitfire_data_access_exception(regs, sfsr, sfar);
 695                 goto out;
 696         }
 697         advance(regs);
 698 out:
 699         exception_exit(prev_state);
 700 }