arch/x86/math-emu/load_store.c

   1 /*---------------------------------------------------------------------------+
   2  |  load_store.c                                                             |
   3  |                                                                           |
   4  | This file contains most of the code to interpret the FPU instructions     |
   5  | which load and store from user memory.                                    |
   6  |                                                                           |
   7  | Copyright (C) 1992,1993,1994,1997                                         |
   8  |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
   9  |                       Australia.  E-mail   billm@suburbia.net             |
  10  |                                                                           |
  11  |                                                                           |
  12  +---------------------------------------------------------------------------*/
  13
  14 /*---------------------------------------------------------------------------+
  15  | Note:                                                                     |
  16  |    The file contains code which accesses user memory.                     |
  17  |    Emulator static data may change when user memory is accessed, due to   |
  18  |    other processes using the emulator while swapping is in progress.      |
  19  +---------------------------------------------------------------------------*/
  20
  21 #include <linux/uaccess.h>
  22
  23 #include "fpu_system.h"
  24 #include "exception.h"
  25 #include "fpu_emu.h"
  26 #include "status_w.h"
  27 #include "control_w.h"
  28
  29 #define _NONE_ 0                /* st0_ptr etc not needed */
  30 #define _REG0_ 1                /* Will be storing st(0) */
  31 #define _PUSH_ 3                /* Need to check for space to push onto stack */
  32 #define _null_ 4                /* Function illegal or not implemented */
  33
  34 #define pop_0() { FPU_settag0(TAG_Empty); top++; }
  35
  36 /* index is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */
  37 static u_char const type_table[32] = {
  38         _PUSH_, _PUSH_, _PUSH_, _PUSH_, /* /0: d9:fld f32,  db:fild m32,  dd:fld f64,  df:fild m16 */
  39         _null_, _REG0_, _REG0_, _REG0_, /* /1: d9:undef,    db,dd,df:fisttp m32/64/16 */
  40         _REG0_, _REG0_, _REG0_, _REG0_, /* /2: d9:fst f32,  db:fist m32,  dd:fst f64,  df:fist m16 */
  41         _REG0_, _REG0_, _REG0_, _REG0_, /* /3: d9:fstp f32, db:fistp m32, dd:fstp f64, df:fistp m16 */
  42         _NONE_, _null_, _NONE_, _PUSH_,
  43         _NONE_, _PUSH_, _null_, _PUSH_,
  44         _NONE_, _null_, _NONE_, _REG0_,
  45         _NONE_, _REG0_, _NONE_, _REG0_
  46 };
  47
  48 u_char const data_sizes_16[32] = {
  49         4, 4, 8, 2,
  50         0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
  51         4, 4, 8, 2,
  52         4, 4, 8, 2,
  53         14, 0, 94, 10, 2, 10, 0, 8,
  54         14, 0, 94, 10, 2, 10, 2, 8
  55 };
  56
  57 static u_char const data_sizes_32[32] = {
  58         4, 4, 8, 2,
  59         0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
  60         4, 4, 8, 2,
  61         4, 4, 8, 2,
  62         28, 0, 108, 10, 2, 10, 0, 8,
  63         28, 0, 108, 10, 2, 10, 2, 8
  64 };
  65
  66 int FPU_load_store(u_char type, fpu_addr_modes addr_modes,
  67                    void __user * data_address)
  68 {
  69         FPU_REG loaded_data;
  70         FPU_REG *st0_ptr;
  71         u_char st0_tag = TAG_Empty;     /* This is just to stop a gcc warning. */
  72         u_char loaded_tag;
  73         int sv_cw;
  74
  75         st0_ptr = NULL;         /* Initialized just to stop compiler warnings. */
  76
  77         if (addr_modes.default_mode & PROTECTED) {
  78                 if (addr_modes.default_mode == SEG32) {
  79                         if (access_limit < data_sizes_32[type])
  80                                 math_abort(FPU_info, SIGSEGV);
  81                 } else if (addr_modes.default_mode == PM16) {
  82                         if (access_limit < data_sizes_16[type])
  83                                 math_abort(FPU_info, SIGSEGV);
  84                 }
  85 #ifdef PARANOID
  86                 else
  87                         EXCEPTION(EX_INTERNAL | 0x140);
  88 #endif /* PARANOID */
  89         }
  90
  91         switch (type_table[type]) {
  92         case _NONE_:
  93                 break;
  94         case _REG0_:
  95                 st0_ptr = &st(0);       /* Some of these instructions pop after
  96                                            storing */
  97                 st0_tag = FPU_gettag0();
  98                 break;
  99         case _PUSH_:
 100                 {
 101                         if (FPU_gettagi(-1) != TAG_Empty) {
 102                                 FPU_stack_overflow();
 103                                 return 0;
 104                         }
 105                         top--;
 106                         st0_ptr = &st(0);
 107                 }
 108                 break;
 109         case _null_:
 110                 FPU_illegal();
 111                 return 0;
 112 #ifdef PARANOID
 113         default:
 114                 EXCEPTION(EX_INTERNAL | 0x141);
 115                 return 0;
 116 #endif /* PARANOID */
 117         }
 118
 119         switch (type) {
 120         /* type is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */
 121         case 000:               /* fld m32real (d9 /0) */
 122                 clear_C1();
 123                 loaded_tag =
 124                     FPU_load_single((float __user *)data_address, &loaded_data);
 125                 if ((loaded_tag == TAG_Special)
 126                     && isNaN(&loaded_data)
 127                     && (real_1op_NaN(&loaded_data) < 0)) {
 128                         top++;
 129                         break;
 130                 }
 131                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
 132                 break;
 133         case 001:               /* fild m32int (db /0) */
 134                 clear_C1();
 135                 loaded_tag =
 136                     FPU_load_int32((long __user *)data_address, &loaded_data);
 137                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
 138                 break;
 139         case 002:               /* fld m64real (dd /0) */
 140                 clear_C1();
 141                 loaded_tag =
 142                     FPU_load_double((double __user *)data_address,
 143                                     &loaded_data);
 144                 if ((loaded_tag == TAG_Special)
 145                     && isNaN(&loaded_data)
 146                     && (real_1op_NaN(&loaded_data) < 0)) {
 147                         top++;
 148                         break;
 149                 }
 150                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
 151                 break;
 152         case 003:               /* fild m16int (df /0) */
 153                 clear_C1();
 154                 loaded_tag =
 155                     FPU_load_int16((short __user *)data_address, &loaded_data);
 156                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
 157                 break;
 158         /* case 004: undefined (d9 /1) */
 159         /* fisttp are enabled if CPUID(1).ECX(0) "sse3" is set */
 160         case 005:               /* fisttp m32int (db /1) */
 161                 clear_C1();
 162                 sv_cw = control_word;
 163                 control_word |= RC_CHOP;
 164                 if (FPU_store_int32
 165                     (st0_ptr, st0_tag, (long __user *)data_address))
 166                         pop_0();        /* pop only if the number was actually stored
 167                                            (see the 80486 manual p16-28) */
 168                 control_word = sv_cw;
 169                 break;
 170         case 006:               /* fisttp m64int (dd /1) */
 171                 clear_C1();
 172                 sv_cw = control_word;
 173                 control_word |= RC_CHOP;
 174                 if (FPU_store_int64
 175                     (st0_ptr, st0_tag, (long long __user *)data_address))
 176                         pop_0();        /* pop only if the number was actually stored
 177                                            (see the 80486 manual p16-28) */
 178                 control_word = sv_cw;
 179                 break;
 180         case 007:               /* fisttp m16int (df /1) */
 181                 clear_C1();
 182                 sv_cw = control_word;
 183                 control_word |= RC_CHOP;
 184                 if (FPU_store_int16
 185                     (st0_ptr, st0_tag, (short __user *)data_address))
 186                         pop_0();        /* pop only if the number was actually stored
 187                                            (see the 80486 manual p16-28) */
 188                 control_word = sv_cw;
 189                 break;
 190         case 010:               /* fst m32real */
 191                 clear_C1();
 192                 FPU_store_single(st0_ptr, st0_tag,
 193                                  (float __user *)data_address);
 194                 break;
 195         case 011:               /* fist m32int */
 196                 clear_C1();
 197                 FPU_store_int32(st0_ptr, st0_tag, (long __user *)data_address);
 198                 break;
 199         case 012:               /* fst m64real */
 200                 clear_C1();
 201                 FPU_store_double(st0_ptr, st0_tag,
 202                                  (double __user *)data_address);
 203                 break;
 204         case 013:               /* fist m16int */
 205                 clear_C1();
 206                 FPU_store_int16(st0_ptr, st0_tag, (short __user *)data_address);
 207                 break;
 208         case 014:               /* fstp m32real */
 209                 clear_C1();
 210                 if (FPU_store_single
 211                     (st0_ptr, st0_tag, (float __user *)data_address))
 212                         pop_0();        /* pop only if the number was actually stored
 213                                            (see the 80486 manual p16-28) */
 214                 break;
 215         case 015:               /* fistp m32int */
 216                 clear_C1();
 217                 if (FPU_store_int32
 218                     (st0_ptr, st0_tag, (long __user *)data_address))
 219                         pop_0();        /* pop only if the number was actually stored
 220                                            (see the 80486 manual p16-28) */
 221                 break;
 222         case 016:               /* fstp m64real */
 223                 clear_C1();
 224                 if (FPU_store_double
 225                     (st0_ptr, st0_tag, (double __user *)data_address))
 226                         pop_0();        /* pop only if the number was actually stored
 227                                            (see the 80486 manual p16-28) */
 228                 break;
 229         case 017:               /* fistp m16int */
 230                 clear_C1();
 231                 if (FPU_store_int16
 232                     (st0_ptr, st0_tag, (short __user *)data_address))
 233                         pop_0();        /* pop only if the number was actually stored
 234                                            (see the 80486 manual p16-28) */
 235                 break;
 236         case 020:               /* fldenv  m14/28byte */
 237                 fldenv(addr_modes, (u_char __user *) data_address);
 238                 /* Ensure that the values just loaded are not changed by
 239                    fix-up operations. */
 240                 return 1;
 241         case 022:               /* frstor m94/108byte */
 242                 frstor(addr_modes, (u_char __user *) data_address);
 243                 /* Ensure that the values just loaded are not changed by
 244                    fix-up operations. */
 245                 return 1;
 246         case 023:               /* fbld m80dec */
 247                 clear_C1();
 248                 loaded_tag = FPU_load_bcd((u_char __user *) data_address);
 249                 FPU_settag0(loaded_tag);
 250                 break;
 251         case 024:               /* fldcw */
 252                 RE_ENTRANT_CHECK_OFF;
 253                 FPU_access_ok(VERIFY_READ, data_address, 2);
 254                 FPU_get_user(control_word,
 255                              (unsigned short __user *)data_address);
 256                 RE_ENTRANT_CHECK_ON;
 257                 if (partial_status & ~control_word & CW_Exceptions)
 258                         partial_status |= (SW_Summary | SW_Backward);
 259                 else
 260                         partial_status &= ~(SW_Summary | SW_Backward);
 261 #ifdef PECULIAR_486
 262                 control_word |= 0x40;   /* An 80486 appears to always set this bit */
 263 #endif /* PECULIAR_486 */
 264                 return 1;
 265         case 025:               /* fld m80real */
 266                 clear_C1();
 267                 loaded_tag =
 268                     FPU_load_extended((long double __user *)data_address, 0);
 269                 FPU_settag0(loaded_tag);
 270                 break;
 271         case 027:               /* fild m64int */
 272                 clear_C1();
 273                 loaded_tag = FPU_load_int64((long long __user *)data_address);
 274                 if (loaded_tag == TAG_Error)
 275                         return 0;
 276                 FPU_settag0(loaded_tag);
 277                 break;
 278         case 030:               /* fstenv  m14/28byte */
 279                 fstenv(addr_modes, (u_char __user *) data_address);
 280                 return 1;
 281         case 032:               /* fsave */
 282                 fsave(addr_modes, (u_char __user *) data_address);
 283                 return 1;
 284         case 033:               /* fbstp m80dec */
 285                 clear_C1();
 286                 if (FPU_store_bcd
 287                     (st0_ptr, st0_tag, (u_char __user *) data_address))
 288                         pop_0();        /* pop only if the number was actually stored
 289                                            (see the 80486 manual p16-28) */
 290                 break;
 291         case 034:               /* fstcw m16int */
 292                 RE_ENTRANT_CHECK_OFF;
 293                 FPU_access_ok(VERIFY_WRITE, data_address, 2);
 294                 FPU_put_user(control_word,
 295                              (unsigned short __user *)data_address);
 296                 RE_ENTRANT_CHECK_ON;
 297                 return 1;
 298         case 035:               /* fstp m80real */
 299                 clear_C1();
 300                 if (FPU_store_extended
 301                     (st0_ptr, st0_tag, (long double __user *)data_address))
 302                         pop_0();        /* pop only if the number was actually stored
 303                                            (see the 80486 manual p16-28) */
 304                 break;
 305         case 036:               /* fstsw m2byte */
 306                 RE_ENTRANT_CHECK_OFF;
 307                 FPU_access_ok(VERIFY_WRITE, data_address, 2);
 308                 FPU_put_user(status_word(),
 309                              (unsigned short __user *)data_address);
 310                 RE_ENTRANT_CHECK_ON;
 311                 return 1;
 312         case 037:               /* fistp m64int */
 313                 clear_C1();
 314                 if (FPU_store_int64
 315                     (st0_ptr, st0_tag, (long long __user *)data_address))
 316                         pop_0();        /* pop only if the number was actually stored
 317                                            (see the 80486 manual p16-28) */
 318                 break;
 319         }
 320         return 0;
 321 }