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