arch/sparc/kernel/unaligned_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * unaligned.c: Unaligned load/store trap handling with special
   4  *              cases for the kernel to do them more quickly.
   5  *
   6  * Copyright (C) 1996,2008 David S. Miller ([email protected])
   7  * Copyright (C) 1996,1997 Jakub Jelinek ([email protected])
   8  */
   9
  10
  11 #include <linux/jiffies.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/mm.h>
  15 #include <linux/extable.h>
  16 #include <asm/asi.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/pstate.h>
  19 #include <asm/processor.h>
  20 #include <linux/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 <linux/context_tracking.h>
  26 #include <asm/fpumacro.h>
  27 #include <asm/cacheflush.h>
  28 #include <asm/setup.h>
  29
  30 #include "entry.h"
  31 #include "kernel.h"
  32
  33 enum direction {
  34         load,    /* ld, ldd, ldh, ldsh */
  35         store,   /* st, std, sth, stsh */
  36         both,    /* Swap, ldstub, cas, ... */
  37         fpld,
  38         fpst,
  39         invalid,
  40 };
  41
  42 static inline enum direction decode_direction(unsigned int insn)
  43 {
  44         unsigned long tmp = (insn >> 21) & 1;
  45
  46         if (!tmp)
  47                 return load;
  48         else {
  49                 switch ((insn>>19)&0xf) {
  50                 case 15: /* swap* */
  51                         return both;
  52                 default:
  53                         return store;
  54                 }
  55         }
  56 }
  57
  58 /* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
  59 static inline int decode_access_size(struct pt_regs *regs, unsigned int insn)
  60 {
  61         unsigned int tmp;
  62
  63         tmp = ((insn >> 19) & 0xf);
  64         if (tmp == 11 || tmp == 14) /* ldx/stx */
  65                 return 8;
  66         tmp &= 3;
  67         if (!tmp)
  68                 return 4;
  69         else if (tmp == 3)
  70                 return 16;      /* ldd/std - Although it is actually 8 */
  71         else if (tmp == 2)
  72                 return 2;
  73         else {
  74                 printk("Impossible unaligned trap. insn=%08x\n", insn);
  75                 die_if_kernel("Byte sized unaligned access?!?!", regs);
  76
  77                 /* GCC should never warn that control reaches the end
  78                  * of this function without returning a value because
  79                  * die_if_kernel() is marked with attribute 'noreturn'.
  80                  * Alas, some versions do...
  81                  */
  82
  83                 return 0;
  84         }
  85 }
  86
  87 static inline int decode_asi(unsigned int insn, struct pt_regs *regs)
  88 {
  89         if (insn & 0x800000) {
  90                 if (insn & 0x2000)
  91                         return (unsigned char)(regs->tstate >> 24);     /* %asi */
  92                 else
  93                         return (unsigned char)(insn >> 5);              /* imm_asi */
  94         } else
  95                 return ASI_P;
  96 }
  97
  98 /* 0x400000 = signed, 0 = unsigned */
  99 static inline int decode_signedness(unsigned int insn)
 100 {
 101         return (insn & 0x400000);
 102 }
 103
 104 static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
 105                                        unsigned int rd, int from_kernel)
 106 {
 107         if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
 108                 if (from_kernel != 0)
 109                         __asm__ __volatile__("flushw");
 110                 else
 111                         flushw_user();
 112         }
 113 }
 114
 115 static inline long sign_extend_imm13(long imm)
 116 {
 117         return imm << 51 >> 51;
 118 }
 119
 120 static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
 121 {
 122         unsigned long value, fp;
 123
 124         if (reg < 16)
 125                 return (!reg ? 0 : regs->u_regs[reg]);
 126
 127         fp = regs->u_regs[UREG_FP];
 128
 129         if (regs->tstate & TSTATE_PRIV) {
 130                 struct reg_window *win;
 131                 win = (struct reg_window *)(fp + STACK_BIAS);
 132                 value = win->locals[reg - 16];
 133         } else if (!test_thread_64bit_stack(fp)) {
 134                 struct reg_window32 __user *win32;
 135                 win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 136                 get_user(value, &win32->locals[reg - 16]);
 137         } else {
 138                 struct reg_window __user *win;
 139                 win = (struct reg_window __user *)(fp + STACK_BIAS);
 140                 get_user(value, &win->locals[reg - 16]);
 141         }
 142         return value;
 143 }
 144
 145 static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
 146 {
 147         unsigned long fp;
 148
 149         if (reg < 16)
 150                 return &regs->u_regs[reg];
 151
 152         fp = regs->u_regs[UREG_FP];
 153
 154         if (regs->tstate & TSTATE_PRIV) {
 155                 struct reg_window *win;
 156                 win = (struct reg_window *)(fp + STACK_BIAS);
 157                 return &win->locals[reg - 16];
 158         } else if (!test_thread_64bit_stack(fp)) {
 159                 struct reg_window32 *win32;
 160                 win32 = (struct reg_window32 *)((unsigned long)((u32)fp));
 161                 return (unsigned long *)&win32->locals[reg - 16];
 162         } else {
 163                 struct reg_window *win;
 164                 win = (struct reg_window *)(fp + STACK_BIAS);
 165                 return &win->locals[reg - 16];
 166         }
 167 }
 168
 169 unsigned long compute_effective_address(struct pt_regs *regs,
 170                                         unsigned int insn, unsigned int rd)
 171 {
 172         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 173         unsigned int rs1 = (insn >> 14) & 0x1f;
 174         unsigned int rs2 = insn & 0x1f;
 175         unsigned long addr;
 176
 177         if (insn & 0x2000) {
 178                 maybe_flush_windows(rs1, 0, rd, from_kernel);
 179                 addr = (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
 180         } else {
 181                 maybe_flush_windows(rs1, rs2, rd, from_kernel);
 182                 addr = (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
 183         }
 184
 185         if (!from_kernel && test_thread_flag(TIF_32BIT))
 186                 addr &= 0xffffffff;
 187
 188         return addr;
 189 }
 190
 191 /* This is just to make gcc think die_if_kernel does return... */
 192 static void __used unaligned_panic(char *str, struct pt_regs *regs)
 193 {
 194         die_if_kernel(str, regs);
 195 }
 196
 197 extern int do_int_load(unsigned long *dest_reg, int size,
 198                        unsigned long *saddr, int is_signed, int asi);
 199
 200 extern int __do_int_store(unsigned long *dst_addr, int size,
 201                           unsigned long src_val, int asi);
 202
 203 static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
 204                                struct pt_regs *regs, int asi, int orig_asi)
 205 {
 206         unsigned long zero = 0;
 207         unsigned long *src_val_p = &zero;
 208         unsigned long src_val;
 209
 210         if (size == 16) {
 211                 size = 8;
 212                 zero = (((long)(reg_num ?
 213                         (unsigned int)fetch_reg(reg_num, regs) : 0)) << 32) |
 214                         (unsigned int)fetch_reg(reg_num + 1, regs);
 215         } else if (reg_num) {
 216                 src_val_p = fetch_reg_addr(reg_num, regs);
 217         }
 218         src_val = *src_val_p;
 219         if (unlikely(asi != orig_asi)) {
 220                 switch (size) {
 221                 case 2:
 222                         src_val = swab16(src_val);
 223                         break;
 224                 case 4:
 225                         src_val = swab32(src_val);
 226                         break;
 227                 case 8:
 228                         src_val = swab64(src_val);
 229                         break;
 230                 case 16:
 231                 default:
 232                         BUG();
 233                         break;
 234                 }
 235         }
 236         return __do_int_store(dst_addr, size, src_val, asi);
 237 }
 238
 239 static inline void advance(struct pt_regs *regs)
 240 {
 241         regs->tpc   = regs->tnpc;
 242         regs->tnpc += 4;
 243         if (test_thread_flag(TIF_32BIT)) {
 244                 regs->tpc &= 0xffffffff;
 245                 regs->tnpc &= 0xffffffff;
 246         }
 247 }
 248
 249 static inline int floating_point_load_or_store_p(unsigned int insn)
 250 {
 251         return (insn >> 24) & 1;
 252 }
 253
 254 static inline int ok_for_kernel(unsigned int insn)
 255 {
 256         return !floating_point_load_or_store_p(insn);
 257 }
 258
 259 static void kernel_mna_trap_fault(int fixup_tstate_asi)
 260 {
 261         struct pt_regs *regs = current_thread_info()->kern_una_regs;
 262         unsigned int insn = current_thread_info()->kern_una_insn;
 263         const struct exception_table_entry *entry;
 264
 265         entry = search_exception_tables(regs->tpc);
 266         if (!entry) {
 267                 unsigned long address;
 268
 269                 address = compute_effective_address(regs, insn,
 270                                                     ((insn >> 25) & 0x1f));
 271                 if (address < PAGE_SIZE) {
 272                         printk(KERN_ALERT "Unable to handle kernel NULL "
 273                                "pointer dereference in mna handler");
 274                 } else
 275                         printk(KERN_ALERT "Unable to handle kernel paging "
 276                                "request in mna handler");
 277                 printk(KERN_ALERT " at virtual address %016lx\n",address);
 278                 printk(KERN_ALERT "current->{active_,}mm->context = %016lx\n",
 279                         (current->mm ? CTX_HWBITS(current->mm->context) :
 280                         CTX_HWBITS(current->active_mm->context)));
 281                 printk(KERN_ALERT "current->{active_,}mm->pgd = %016lx\n",
 282                         (current->mm ? (unsigned long) current->mm->pgd :
 283                         (unsigned long) current->active_mm->pgd));
 284                 die_if_kernel("Oops", regs);
 285                 /* Not reached */
 286         }
 287         regs->tpc = entry->fixup;
 288         regs->tnpc = regs->tpc + 4;
 289
 290         if (fixup_tstate_asi) {
 291                 regs->tstate &= ~TSTATE_ASI;
 292                 regs->tstate |= (ASI_AIUS << 24UL);
 293         }
 294 }
 295
 296 static void log_unaligned(struct pt_regs *regs)
 297 {
 298         static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
 299
 300         if (__ratelimit(&ratelimit)) {
 301                 printk("Kernel unaligned access at TPC[%lx] %pS\n",
 302                        regs->tpc, (void *) regs->tpc);
 303         }
 304 }
 305
 306 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 307 {
 308         enum direction dir = decode_direction(insn);
 309         int size = decode_access_size(regs, insn);
 310         int orig_asi, asi;
 311
 312         current_thread_info()->kern_una_regs = regs;
 313         current_thread_info()->kern_una_insn = insn;
 314
 315         orig_asi = asi = decode_asi(insn, regs);
 316
 317         /* If this is a {get,put}_user() on an unaligned userspace pointer,
 318          * just signal a fault and do not log the event.
 319          */
 320         if (asi == ASI_AIUS) {
 321                 kernel_mna_trap_fault(0);
 322                 return;
 323         }
 324
 325         log_unaligned(regs);
 326
 327         if (!ok_for_kernel(insn) || dir == both) {
 328                 printk("Unsupported unaligned load/store trap for kernel "
 329                        "at <%016lx>.\n", regs->tpc);
 330                 unaligned_panic("Kernel does fpu/atomic "
 331                                 "unaligned load/store.", regs);
 332
 333                 kernel_mna_trap_fault(0);
 334         } else {
 335                 unsigned long addr, *reg_addr;
 336                 int err;
 337
 338                 addr = compute_effective_address(regs, insn,
 339                                                  ((insn >> 25) & 0x1f));
 340                 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
 341                 switch (asi) {
 342                 case ASI_NL:
 343                 case ASI_AIUPL:
 344                 case ASI_AIUSL:
 345                 case ASI_PL:
 346                 case ASI_SL:
 347                 case ASI_PNFL:
 348                 case ASI_SNFL:
 349                         asi &= ~0x08;
 350                         break;
 351                 }
 352                 switch (dir) {
 353                 case load:
 354                         reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
 355                         err = do_int_load(reg_addr, size,
 356                                           (unsigned long *) addr,
 357                                           decode_signedness(insn), asi);
 358                         if (likely(!err) && unlikely(asi != orig_asi)) {
 359                                 unsigned long val_in = *reg_addr;
 360                                 switch (size) {
 361                                 case 2:
 362                                         val_in = swab16(val_in);
 363                                         break;
 364                                 case 4:
 365                                         val_in = swab32(val_in);
 366                                         break;
 367                                 case 8:
 368                                         val_in = swab64(val_in);
 369                                         break;
 370                                 case 16:
 371                                 default:
 372                                         BUG();
 373                                         break;
 374                                 }
 375                                 *reg_addr = val_in;
 376                         }
 377                         break;
 378
 379                 case store:
 380                         err = do_int_store(((insn>>25)&0x1f), size,
 381                                            (unsigned long *) addr, regs,
 382                                            asi, orig_asi);
 383                         break;
 384
 385                 default:
 386                         panic("Impossible kernel unaligned trap.");
 387                         /* Not reached... */
 388                 }
 389                 if (unlikely(err))
 390                         kernel_mna_trap_fault(1);
 391                 else
 392                         advance(regs);
 393         }
 394 }
 395
 396 int handle_popc(u32 insn, struct pt_regs *regs)
 397 {
 398         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 399         int ret, rd = ((insn >> 25) & 0x1f);
 400         u64 value;
 401
 402         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 403         if (insn & 0x2000) {
 404                 maybe_flush_windows(0, 0, rd, from_kernel);
 405                 value = sign_extend_imm13(insn);
 406         } else {
 407                 maybe_flush_windows(0, insn & 0x1f, rd, from_kernel);
 408                 value = fetch_reg(insn & 0x1f, regs);
 409         }
 410         ret = hweight64(value);
 411         if (rd < 16) {
 412                 if (rd)
 413                         regs->u_regs[rd] = ret;
 414         } else {
 415                 unsigned long fp = regs->u_regs[UREG_FP];
 416
 417                 if (!test_thread_64bit_stack(fp)) {
 418                         struct reg_window32 __user *win32;
 419                         win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 420                         put_user(ret, &win32->locals[rd - 16]);
 421                 } else {
 422                         struct reg_window __user *win;
 423                         win = (struct reg_window __user *)(fp + STACK_BIAS);
 424                         put_user(ret, &win->locals[rd - 16]);
 425                 }
 426         }
 427         advance(regs);
 428         return 1;
 429 }
 430
 431 extern void do_fpother(struct pt_regs *regs);
 432 extern void do_privact(struct pt_regs *regs);
 433 extern void sun4v_data_access_exception(struct pt_regs *regs,
 434                                         unsigned long addr,
 435                                         unsigned long type_ctx);
 436
 437 int handle_ldf_stq(u32 insn, struct pt_regs *regs)
 438 {
 439         unsigned long addr = compute_effective_address(regs, insn, 0);
 440         int freg;
 441         struct fpustate *f = FPUSTATE;
 442         int asi = decode_asi(insn, regs);
 443         int flag;
 444
 445         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 446
 447         save_and_clear_fpu();
 448         current_thread_info()->xfsr[0] &= ~0x1c000;
 449         if (insn & 0x200000) {
 450                 /* STQ */
 451                 u64 first = 0, second = 0;
 452
 453                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 454                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 455                 if (freg & 3) {
 456                         current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 457                         do_fpother(regs);
 458                         return 0;
 459                 }
 460                 if (current_thread_info()->fpsaved[0] & flag) {
 461                         first = *(u64 *)&f->regs[freg];
 462                         second = *(u64 *)&f->regs[freg+2];
 463                 }
 464                 if (asi < 0x80) {
 465                         do_privact(regs);
 466                         return 1;
 467                 }
 468                 switch (asi) {
 469                 case ASI_P:
 470                 case ASI_S: break;
 471                 case ASI_PL:
 472                 case ASI_SL:
 473                         {
 474                                 /* Need to convert endians */
 475                                 u64 tmp = __swab64p(&first);
 476
 477                                 first = __swab64p(&second);
 478                                 second = tmp;
 479                                 break;
 480                         }
 481                 default:
 482                         if (tlb_type == hypervisor)
 483                                 sun4v_data_access_exception(regs, addr, 0);
 484                         else
 485                                 spitfire_data_access_exception(regs, 0, addr);
 486                         return 1;
 487                 }
 488                 if (put_user (first >> 32, (u32 __user *)addr) ||
 489                     __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
 490                     __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
 491                     __put_user ((u32)second, (u32 __user *)(addr + 12))) {
 492                         if (tlb_type == hypervisor)
 493                                 sun4v_data_access_exception(regs, addr, 0);
 494                         else
 495                                 spitfire_data_access_exception(regs, 0, addr);
 496                         return 1;
 497                 }
 498         } else {
 499                 /* LDF, LDDF, LDQF */
 500                 u32 data[4] __attribute__ ((aligned(8)));
 501                 int size, i;
 502                 int err;
 503
 504                 if (asi < 0x80) {
 505                         do_privact(regs);
 506                         return 1;
 507                 } else if (asi > ASI_SNFL) {
 508                         if (tlb_type == hypervisor)
 509                                 sun4v_data_access_exception(regs, addr, 0);
 510                         else
 511                                 spitfire_data_access_exception(regs, 0, addr);
 512                         return 1;
 513                 }
 514                 switch (insn & 0x180000) {
 515                 case 0x000000: size = 1; break;
 516                 case 0x100000: size = 4; break;
 517                 default: size = 2; break;
 518                 }
 519                 if (size == 1)
 520                         freg = (insn >> 25) & 0x1f;
 521                 else
 522                         freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 523                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 524
 525                 for (i = 0; i < size; i++)
 526                         data[i] = 0;
 527
 528                 err = get_user (data[0], (u32 __user *) addr);
 529                 if (!err) {
 530                         for (i = 1; i < size; i++)
 531                                 err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
 532                 }
 533                 if (err && !(asi & 0x2 /* NF */)) {
 534                         if (tlb_type == hypervisor)
 535                                 sun4v_data_access_exception(regs, addr, 0);
 536                         else
 537                                 spitfire_data_access_exception(regs, 0, addr);
 538                         return 1;
 539                 }
 540                 if (asi & 0x8) /* Little */ {
 541                         u64 tmp;
 542
 543                         switch (size) {
 544                         case 1: data[0] = le32_to_cpup(data + 0); break;
 545                         default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
 546                                 break;
 547                         case 4: tmp = le64_to_cpup((u64 *)(data + 0));
 548                                 *(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
 549                                 *(u64 *)(data + 2) = tmp;
 550                                 break;
 551                         }
 552                 }
 553                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 554                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 555                         current_thread_info()->gsr[0] = 0;
 556                 }
 557                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 558                         if (freg < 32)
 559                                 memset(f->regs, 0, 32*sizeof(u32));
 560                         else
 561                                 memset(f->regs+32, 0, 32*sizeof(u32));
 562                 }
 563                 memcpy(f->regs + freg, data, size * 4);
 564                 current_thread_info()->fpsaved[0] |= flag;
 565         }
 566         advance(regs);
 567         return 1;
 568 }
 569
 570 void handle_ld_nf(u32 insn, struct pt_regs *regs)
 571 {
 572         int rd = ((insn >> 25) & 0x1f);
 573         int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 574         unsigned long *reg;
 575
 576         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 577
 578         maybe_flush_windows(0, 0, rd, from_kernel);
 579         reg = fetch_reg_addr(rd, regs);
 580         if (from_kernel || rd < 16) {
 581                 reg[0] = 0;
 582                 if ((insn & 0x780000) == 0x180000)
 583                         reg[1] = 0;
 584         } else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) {
 585                 put_user(0, (int __user *) reg);
 586                 if ((insn & 0x780000) == 0x180000)
 587                         put_user(0, ((int __user *) reg) + 1);
 588         } else {
 589                 put_user(0, (unsigned long __user *) reg);
 590                 if ((insn & 0x780000) == 0x180000)
 591                         put_user(0, (unsigned long __user *) reg + 1);
 592         }
 593         advance(regs);
 594 }
 595
 596 void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 597 {
 598         enum ctx_state prev_state = exception_enter();
 599         unsigned long pc = regs->tpc;
 600         unsigned long tstate = regs->tstate;
 601         u32 insn;
 602         u64 value;
 603         u8 freg;
 604         int flag;
 605         struct fpustate *f = FPUSTATE;
 606
 607         if (tstate & TSTATE_PRIV)
 608                 die_if_kernel("lddfmna from kernel", regs);
 609         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 610         if (test_thread_flag(TIF_32BIT))
 611                 pc = (u32)pc;
 612         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 613                 int asi = decode_asi(insn, regs);
 614                 u32 first, second;
 615                 int err;
 616
 617                 if ((asi > ASI_SNFL) ||
 618                     (asi < ASI_P))
 619                         goto daex;
 620                 first = second = 0;
 621                 err = get_user(first, (u32 __user *)sfar);
 622                 if (!err)
 623                         err = get_user(second, (u32 __user *)(sfar + 4));
 624                 if (err) {
 625                         if (!(asi & 0x2))
 626                                 goto daex;
 627                         first = second = 0;
 628                 }
 629                 save_and_clear_fpu();
 630                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 631                 value = (((u64)first) << 32) | second;
 632                 if (asi & 0x8) /* Little */
 633                         value = __swab64p(&value);
 634                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 635                 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 636                         current_thread_info()->fpsaved[0] = FPRS_FEF;
 637                         current_thread_info()->gsr[0] = 0;
 638                 }
 639                 if (!(current_thread_info()->fpsaved[0] & flag)) {
 640                         if (freg < 32)
 641                                 memset(f->regs, 0, 32*sizeof(u32));
 642                         else
 643                                 memset(f->regs+32, 0, 32*sizeof(u32));
 644                 }
 645                 *(u64 *)(f->regs + freg) = value;
 646                 current_thread_info()->fpsaved[0] |= flag;
 647         } else {
 648 daex:
 649                 if (tlb_type == hypervisor)
 650                         sun4v_data_access_exception(regs, sfar, sfsr);
 651                 else
 652                         spitfire_data_access_exception(regs, sfsr, sfar);
 653                 goto out;
 654         }
 655         advance(regs);
 656 out:
 657         exception_exit(prev_state);
 658 }
 659
 660 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 661 {
 662         enum ctx_state prev_state = exception_enter();
 663         unsigned long pc = regs->tpc;
 664         unsigned long tstate = regs->tstate;
 665         u32 insn;
 666         u64 value;
 667         u8 freg;
 668         int flag;
 669         struct fpustate *f = FPUSTATE;
 670
 671         if (tstate & TSTATE_PRIV)
 672                 die_if_kernel("stdfmna from kernel", regs);
 673         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 674         if (test_thread_flag(TIF_32BIT))
 675                 pc = (u32)pc;
 676         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 677                 int asi = decode_asi(insn, regs);
 678                 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 679                 value = 0;
 680                 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 681                 if ((asi > ASI_SNFL) ||
 682                     (asi < ASI_P))
 683                         goto daex;
 684                 save_and_clear_fpu();
 685                 if (current_thread_info()->fpsaved[0] & flag)
 686                         value = *(u64 *)&f->regs[freg];
 687                 switch (asi) {
 688                 case ASI_P:
 689                 case ASI_S: break;
 690                 case ASI_PL:
 691                 case ASI_SL:
 692                         value = __swab64p(&value); break;
 693                 default: goto daex;
 694                 }
 695                 if (put_user (value >> 32, (u32 __user *) sfar) ||
 696                     __put_user ((u32)value, (u32 __user *)(sfar + 4)))
 697                         goto daex;
 698         } else {
 699 daex:
 700                 if (tlb_type == hypervisor)
 701                         sun4v_data_access_exception(regs, sfar, sfsr);
 702                 else
 703                         spitfire_data_access_exception(regs, sfsr, sfar);
 704                 goto out;
 705         }
 706         advance(regs);
 707 out:
 708         exception_exit(prev_state);
 709 }