arch/sparc/lib/copy_user.S

   1 /* copy_user.S: Sparc optimized copy_from_user and copy_to_user code.
   2  *
   3  *  Copyright(C) 1995 Linus Torvalds
   4  *  Copyright(C) 1996 David S. Miller
   5  *  Copyright(C) 1996 Eddie C. Dost
   6  *  Copyright(C) 1996,1998 Jakub Jelinek
   7  *
   8  * derived from:
   9  *      e-mail between David and Eddie.
  10  *
  11  * Returns 0 if successful, otherwise count of bytes not copied yet
  12  */
  13
  14 #include <asm/ptrace.h>
  15 #include <asm/asmmacro.h>
  16 #include <asm/page.h>
  17 #include <asm/thread_info.h>
  18
  19 /* Work around cpp -rob */
  20 #define ALLOC #alloc
  21 #define EXECINSTR #execinstr
  22 #define EX(x,y,a,b)                             \
  23 98:     x,y;                                    \
  24         .section .fixup,ALLOC,EXECINSTR;        \
  25         .align  4;                              \
  26 99:     ba fixupretl;                           \
  27          a, b, %g3;                             \
  28         .section __ex_table,ALLOC;              \
  29         .align  4;                              \
  30         .word   98b, 99b;                       \
  31         .text;                                  \
  32         .align  4
  33
  34 #define EX2(x,y,c,d,e,a,b)                      \
  35 98:     x,y;                                    \
  36         .section .fixup,ALLOC,EXECINSTR;        \
  37         .align  4;                              \
  38 99:     c, d, e;                                \
  39         ba fixupretl;                           \
  40          a, b, %g3;                             \
  41         .section __ex_table,ALLOC;              \
  42         .align  4;                              \
  43         .word   98b, 99b;                       \
  44         .text;                                  \
  45         .align  4
  46
  47 #define EXO2(x,y)                               \
  48 98:     x, y;                                   \
  49         .section __ex_table,ALLOC;              \
  50         .align  4;                              \
  51         .word   98b, 97f;                       \
  52         .text;                                  \
  53         .align  4
  54
  55 #define EXT(start,end,handler)                  \
  56         .section __ex_table,ALLOC;              \
  57         .align  4;                              \
  58         .word   start, 0, end, handler;         \
  59         .text;                                  \
  60         .align  4
  61
  62 /* Please do not change following macros unless you change logic used
  63  * in .fixup at the end of this file as well
  64  */
  65
  66 /* Both these macros have to start with exactly the same insn */
  67 #define MOVE_BIGCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
  68         ldd     [%src + (offset) + 0x00], %t0; \
  69         ldd     [%src + (offset) + 0x08], %t2; \
  70         ldd     [%src + (offset) + 0x10], %t4; \
  71         ldd     [%src + (offset) + 0x18], %t6; \
  72         st      %t0, [%dst + (offset) + 0x00]; \
  73         st      %t1, [%dst + (offset) + 0x04]; \
  74         st      %t2, [%dst + (offset) + 0x08]; \
  75         st      %t3, [%dst + (offset) + 0x0c]; \
  76         st      %t4, [%dst + (offset) + 0x10]; \
  77         st      %t5, [%dst + (offset) + 0x14]; \
  78         st      %t6, [%dst + (offset) + 0x18]; \
  79         st      %t7, [%dst + (offset) + 0x1c];
  80
  81 #define MOVE_BIGALIGNCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
  82         ldd     [%src + (offset) + 0x00], %t0; \
  83         ldd     [%src + (offset) + 0x08], %t2; \
  84         ldd     [%src + (offset) + 0x10], %t4; \
  85         ldd     [%src + (offset) + 0x18], %t6; \
  86         std     %t0, [%dst + (offset) + 0x00]; \
  87         std     %t2, [%dst + (offset) + 0x08]; \
  88         std     %t4, [%dst + (offset) + 0x10]; \
  89         std     %t6, [%dst + (offset) + 0x18];
  90
  91 #define MOVE_LASTCHUNK(src, dst, offset, t0, t1, t2, t3) \
  92         ldd     [%src - (offset) - 0x10], %t0; \
  93         ldd     [%src - (offset) - 0x08], %t2; \
  94         st      %t0, [%dst - (offset) - 0x10]; \
  95         st      %t1, [%dst - (offset) - 0x0c]; \
  96         st      %t2, [%dst - (offset) - 0x08]; \
  97         st      %t3, [%dst - (offset) - 0x04];
  98
  99 #define MOVE_HALFCHUNK(src, dst, offset, t0, t1, t2, t3) \
 100         lduh    [%src + (offset) + 0x00], %t0; \
 101         lduh    [%src + (offset) + 0x02], %t1; \
 102         lduh    [%src + (offset) + 0x04], %t2; \
 103         lduh    [%src + (offset) + 0x06], %t3; \
 104         sth     %t0, [%dst + (offset) + 0x00]; \
 105         sth     %t1, [%dst + (offset) + 0x02]; \
 106         sth     %t2, [%dst + (offset) + 0x04]; \
 107         sth     %t3, [%dst + (offset) + 0x06];
 108
 109 #define MOVE_SHORTCHUNK(src, dst, offset, t0, t1) \
 110         ldub    [%src - (offset) - 0x02], %t0; \
 111         ldub    [%src - (offset) - 0x01], %t1; \
 112         stb     %t0, [%dst - (offset) - 0x02]; \
 113         stb     %t1, [%dst - (offset) - 0x01];
 114
 115         .text
 116         .align  4
 117
 118         .globl  __copy_user_begin
 119 __copy_user_begin:
 120
 121         .globl  __copy_user
 122 dword_align:
 123         andcc   %o1, 1, %g0
 124         be      4f
 125          andcc  %o1, 2, %g0
 126
 127         EXO2(ldub [%o1], %g2)
 128         add     %o1, 1, %o1
 129         EXO2(stb %g2, [%o0])
 130         sub     %o2, 1, %o2
 131         bne     3f
 132          add    %o0, 1, %o0
 133
 134         EXO2(lduh [%o1], %g2)
 135         add     %o1, 2, %o1
 136         EXO2(sth %g2, [%o0])
 137         sub     %o2, 2, %o2
 138         b       3f
 139          add    %o0, 2, %o0
 140 4:
 141         EXO2(lduh [%o1], %g2)
 142         add     %o1, 2, %o1
 143         EXO2(sth %g2, [%o0])
 144         sub     %o2, 2, %o2
 145         b       3f
 146          add    %o0, 2, %o0
 147
 148 __copy_user:    /* %o0=dst %o1=src %o2=len */
 149         xor     %o0, %o1, %o4
 150 1:
 151         andcc   %o4, 3, %o5
 152 2:
 153         bne     cannot_optimize
 154          cmp    %o2, 15
 155
 156         bleu    short_aligned_end
 157          andcc  %o1, 3, %g0
 158
 159         bne     dword_align
 160 3:
 161          andcc  %o1, 4, %g0
 162
 163         be      2f
 164          mov    %o2, %g1
 165
 166         EXO2(ld [%o1], %o4)
 167         sub     %g1, 4, %g1
 168         EXO2(st %o4, [%o0])
 169         add     %o1, 4, %o1
 170         add     %o0, 4, %o0
 171 2:
 172         andcc   %g1, 0xffffff80, %g7
 173         be      3f
 174          andcc  %o0, 4, %g0
 175
 176         be      ldd_std + 4
 177 5:
 178         MOVE_BIGCHUNK(o1, o0, 0x00, o2, o3, o4, o5, g2, g3, g4, g5)
 179         MOVE_BIGCHUNK(o1, o0, 0x20, o2, o3, o4, o5, g2, g3, g4, g5)
 180         MOVE_BIGCHUNK(o1, o0, 0x40, o2, o3, o4, o5, g2, g3, g4, g5)
 181         MOVE_BIGCHUNK(o1, o0, 0x60, o2, o3, o4, o5, g2, g3, g4, g5)
 182 80:
 183         EXT(5b, 80b, 50f)
 184         subcc   %g7, 128, %g7
 185         add     %o1, 128, %o1
 186         bne     5b
 187          add    %o0, 128, %o0
 188 3:
 189         andcc   %g1, 0x70, %g7
 190         be      copy_user_table_end
 191          andcc  %g1, 8, %g0
 192
 193         sethi   %hi(copy_user_table_end), %o5
 194         srl     %g7, 1, %o4
 195         add     %g7, %o4, %o4
 196         add     %o1, %g7, %o1
 197         sub     %o5, %o4, %o5
 198         jmpl    %o5 + %lo(copy_user_table_end), %g0
 199          add    %o0, %g7, %o0
 200
 201 copy_user_table:
 202         MOVE_LASTCHUNK(o1, o0, 0x60, g2, g3, g4, g5)
 203         MOVE_LASTCHUNK(o1, o0, 0x50, g2, g3, g4, g5)
 204         MOVE_LASTCHUNK(o1, o0, 0x40, g2, g3, g4, g5)
 205         MOVE_LASTCHUNK(o1, o0, 0x30, g2, g3, g4, g5)
 206         MOVE_LASTCHUNK(o1, o0, 0x20, g2, g3, g4, g5)
 207         MOVE_LASTCHUNK(o1, o0, 0x10, g2, g3, g4, g5)
 208         MOVE_LASTCHUNK(o1, o0, 0x00, g2, g3, g4, g5)
 209 copy_user_table_end:
 210         EXT(copy_user_table, copy_user_table_end, 51f)
 211         be      copy_user_last7
 212          andcc  %g1, 4, %g0
 213
 214         EX(ldd  [%o1], %g2, and %g1, 0xf)
 215         add     %o0, 8, %o0
 216         add     %o1, 8, %o1
 217         EX(st   %g2, [%o0 - 0x08], and %g1, 0xf)
 218         EX2(st  %g3, [%o0 - 0x04], and %g1, 0xf, %g1, sub %g1, 4)
 219 copy_user_last7:
 220         be      1f
 221          andcc  %g1, 2, %g0
 222
 223         EX(ld   [%o1], %g2, and %g1, 7)
 224         add     %o1, 4, %o1
 225         EX(st   %g2, [%o0], and %g1, 7)
 226         add     %o0, 4, %o0
 227 1:
 228         be      1f
 229          andcc  %g1, 1, %g0
 230
 231         EX(lduh [%o1], %g2, and %g1, 3)
 232         add     %o1, 2, %o1
 233         EX(sth  %g2, [%o0], and %g1, 3)
 234         add     %o0, 2, %o0
 235 1:
 236         be      1f
 237          nop
 238
 239         EX(ldub [%o1], %g2, add %g0, 1)
 240         EX(stb  %g2, [%o0], add %g0, 1)
 241 1:
 242         retl
 243          clr    %o0
 244
 245 ldd_std:
 246         MOVE_BIGALIGNCHUNK(o1, o0, 0x00, o2, o3, o4, o5, g2, g3, g4, g5)
 247         MOVE_BIGALIGNCHUNK(o1, o0, 0x20, o2, o3, o4, o5, g2, g3, g4, g5)
 248         MOVE_BIGALIGNCHUNK(o1, o0, 0x40, o2, o3, o4, o5, g2, g3, g4, g5)
 249         MOVE_BIGALIGNCHUNK(o1, o0, 0x60, o2, o3, o4, o5, g2, g3, g4, g5)
 250 81:
 251         EXT(ldd_std, 81b, 52f)
 252         subcc   %g7, 128, %g7
 253         add     %o1, 128, %o1
 254         bne     ldd_std
 255          add    %o0, 128, %o0
 256
 257         andcc   %g1, 0x70, %g7
 258         be      copy_user_table_end
 259          andcc  %g1, 8, %g0
 260
 261         sethi   %hi(copy_user_table_end), %o5
 262         srl     %g7, 1, %o4
 263         add     %g7, %o4, %o4
 264         add     %o1, %g7, %o1
 265         sub     %o5, %o4, %o5
 266         jmpl    %o5 + %lo(copy_user_table_end), %g0
 267          add    %o0, %g7, %o0
 268
 269 cannot_optimize:
 270         bleu    short_end
 271          cmp    %o5, 2
 272
 273         bne     byte_chunk
 274          and    %o2, 0xfffffff0, %o3
 275
 276         andcc   %o1, 1, %g0
 277         be      10f
 278          nop
 279
 280         EXO2(ldub [%o1], %g2)
 281         add     %o1, 1, %o1
 282         EXO2(stb %g2, [%o0])
 283         sub     %o2, 1, %o2
 284         andcc   %o2, 0xfffffff0, %o3
 285         be      short_end
 286          add    %o0, 1, %o0
 287 10:
 288         MOVE_HALFCHUNK(o1, o0, 0x00, g2, g3, g4, g5)
 289         MOVE_HALFCHUNK(o1, o0, 0x08, g2, g3, g4, g5)
 290 82:
 291         EXT(10b, 82b, 53f)
 292         subcc   %o3, 0x10, %o3
 293         add     %o1, 0x10, %o1
 294         bne     10b
 295          add    %o0, 0x10, %o0
 296         b       2f
 297          and    %o2, 0xe, %o3
 298
 299 byte_chunk:
 300         MOVE_SHORTCHUNK(o1, o0, -0x02, g2, g3)
 301         MOVE_SHORTCHUNK(o1, o0, -0x04, g2, g3)
 302         MOVE_SHORTCHUNK(o1, o0, -0x06, g2, g3)
 303         MOVE_SHORTCHUNK(o1, o0, -0x08, g2, g3)
 304         MOVE_SHORTCHUNK(o1, o0, -0x0a, g2, g3)
 305         MOVE_SHORTCHUNK(o1, o0, -0x0c, g2, g3)
 306         MOVE_SHORTCHUNK(o1, o0, -0x0e, g2, g3)
 307         MOVE_SHORTCHUNK(o1, o0, -0x10, g2, g3)
 308 83:
 309         EXT(byte_chunk, 83b, 54f)
 310         subcc   %o3, 0x10, %o3
 311         add     %o1, 0x10, %o1
 312         bne     byte_chunk
 313          add    %o0, 0x10, %o0
 314
 315 short_end:
 316         and     %o2, 0xe, %o3
 317 2:
 318         sethi   %hi(short_table_end), %o5
 319         sll     %o3, 3, %o4
 320         add     %o0, %o3, %o0
 321         sub     %o5, %o4, %o5
 322         add     %o1, %o3, %o1
 323         jmpl    %o5 + %lo(short_table_end), %g0
 324          andcc  %o2, 1, %g0
 325 84:
 326         MOVE_SHORTCHUNK(o1, o0, 0x0c, g2, g3)
 327         MOVE_SHORTCHUNK(o1, o0, 0x0a, g2, g3)
 328         MOVE_SHORTCHUNK(o1, o0, 0x08, g2, g3)
 329         MOVE_SHORTCHUNK(o1, o0, 0x06, g2, g3)
 330         MOVE_SHORTCHUNK(o1, o0, 0x04, g2, g3)
 331         MOVE_SHORTCHUNK(o1, o0, 0x02, g2, g3)
 332         MOVE_SHORTCHUNK(o1, o0, 0x00, g2, g3)
 333 short_table_end:
 334         EXT(84b, short_table_end, 55f)
 335         be      1f
 336          nop
 337         EX(ldub [%o1], %g2, add %g0, 1)
 338         EX(stb  %g2, [%o0], add %g0, 1)
 339 1:
 340         retl
 341          clr    %o0
 342
 343 short_aligned_end:
 344         bne     short_end
 345          andcc  %o2, 8, %g0
 346
 347         be      1f
 348          andcc  %o2, 4, %g0
 349
 350         EXO2(ld [%o1 + 0x00], %g2)
 351         EXO2(ld [%o1 + 0x04], %g3)
 352         add     %o1, 8, %o1
 353         EXO2(st %g2, [%o0 + 0x00])
 354         EX(st   %g3, [%o0 + 0x04], sub %o2, 4)
 355         add     %o0, 8, %o0
 356 1:
 357         b       copy_user_last7
 358          mov    %o2, %g1
 359
 360         .section .fixup,#alloc,#execinstr
 361         .align  4
 362 97:
 363         mov     %o2, %g3
 364 fixupretl:
 365         sethi   %hi(PAGE_OFFSET), %g1
 366         cmp     %o0, %g1
 367         blu     1f
 368          cmp    %o1, %g1
 369         bgeu    1f
 370          ld     [%g6 + TI_PREEMPT], %g1
 371         cmp     %g1, 0
 372         bne     1f
 373          nop
 374         save    %sp, -64, %sp
 375         mov     %i0, %o0
 376         call    __bzero
 377          mov    %g3, %o1
 378         restore
 379 1:      retl
 380          mov    %g3, %o0
 381
 382 /* exception routine sets %g2 to (broken_insn - first_insn)>>2 */
 383 50:
 384 /* This magic counts how many bytes are left when crash in MOVE_BIGCHUNK
 385  * happens. This is derived from the amount ldd reads, st stores, etc.
 386  * x = g2 % 12;
 387  * g3 = g1 + g7 - ((g2 / 12) * 32 + (x < 4) ? 0 : (x - 4) * 4);
 388  * o0 += (g2 / 12) * 32;
 389  */
 390         cmp     %g2, 12
 391         add     %o0, %g7, %o0
 392         bcs     1f
 393          cmp    %g2, 24
 394         bcs     2f
 395          cmp    %g2, 36
 396         bcs     3f
 397          nop
 398         sub     %g2, 12, %g2
 399         sub     %g7, 32, %g7
 400 3:      sub     %g2, 12, %g2
 401         sub     %g7, 32, %g7
 402 2:      sub     %g2, 12, %g2
 403         sub     %g7, 32, %g7
 404 1:      cmp     %g2, 4
 405         bcs,a   60f
 406          clr    %g2
 407         sub     %g2, 4, %g2
 408         sll     %g2, 2, %g2
 409 60:     and     %g1, 0x7f, %g3
 410         sub     %o0, %g7, %o0
 411         add     %g3, %g7, %g3
 412         ba      fixupretl
 413          sub    %g3, %g2, %g3
 414 51:
 415 /* i = 41 - g2; j = i % 6;
 416  * g3 = (g1 & 15) + (i / 6) * 16 + (j < 4) ? (j + 1) * 4 : 16;
 417  * o0 -= (i / 6) * 16 + 16;
 418  */
 419         neg     %g2
 420         and     %g1, 0xf, %g1
 421         add     %g2, 41, %g2
 422         add     %o0, %g1, %o0
 423 1:      cmp     %g2, 6
 424         bcs,a   2f
 425          cmp    %g2, 4
 426         add     %g1, 16, %g1
 427         b       1b
 428          sub    %g2, 6, %g2
 429 2:      bcc,a   2f
 430          mov    16, %g2
 431         inc     %g2
 432         sll     %g2, 2, %g2
 433 2:      add     %g1, %g2, %g3
 434         ba      fixupretl
 435          sub    %o0, %g3, %o0
 436 52:
 437 /* g3 = g1 + g7 - (g2 / 8) * 32 + (g2 & 4) ? (g2 & 3) * 8 : 0;
 438    o0 += (g2 / 8) * 32 */
 439         andn    %g2, 7, %g4
 440         add     %o0, %g7, %o0
 441         andcc   %g2, 4, %g0
 442         and     %g2, 3, %g2
 443         sll     %g4, 2, %g4
 444         sll     %g2, 3, %g2
 445         bne     60b
 446          sub    %g7, %g4, %g7
 447         ba      60b
 448          clr    %g2
 449 53:
 450 /* g3 = o3 + (o2 & 15) - (g2 & 8) - (g2 & 4) ? (g2 & 3) * 2 : 0;
 451    o0 += (g2 & 8) */
 452         and     %g2, 3, %g4
 453         andcc   %g2, 4, %g0
 454         and     %g2, 8, %g2
 455         sll     %g4, 1, %g4
 456         be      1f
 457          add    %o0, %g2, %o0
 458         add     %g2, %g4, %g2
 459 1:      and     %o2, 0xf, %g3
 460         add     %g3, %o3, %g3
 461         ba      fixupretl
 462          sub    %g3, %g2, %g3
 463 54:
 464 /* g3 = o3 + (o2 & 15) - (g2 / 4) * 2 - (g2 & 2) ? (g2 & 1) : 0;
 465    o0 += (g2 / 4) * 2 */
 466         srl     %g2, 2, %o4
 467         and     %g2, 1, %o5
 468         srl     %g2, 1, %g2
 469         add     %o4, %o4, %o4
 470         and     %o5, %g2, %o5
 471         and     %o2, 0xf, %o2
 472         add     %o0, %o4, %o0
 473         sub     %o3, %o5, %o3
 474         sub     %o2, %o4, %o2
 475         ba      fixupretl
 476          add    %o2, %o3, %g3
 477 55:
 478 /* i = 27 - g2;
 479    g3 = (o2 & 1) + i / 4 * 2 + !(i & 3);
 480    o0 -= i / 4 * 2 + 1 */
 481         neg     %g2
 482         and     %o2, 1, %o2
 483         add     %g2, 27, %g2
 484         srl     %g2, 2, %o5
 485         andcc   %g2, 3, %g0
 486         mov     1, %g2
 487         add     %o5, %o5, %o5
 488         be,a    1f
 489          clr    %g2
 490 1:      add     %g2, %o5, %g3
 491         sub     %o0, %g3, %o0
 492         ba      fixupretl
 493          add    %g3, %o2, %g3
 494
 495         .globl  __copy_user_end
 496 __copy_user_end: