arch/powerpc/lib/copyuser_64.S

   1 /*
   2  * Copyright (C) 2002 Paul Mackerras, IBM Corp.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  */
   9 #include <asm/processor.h>
  10 #include <asm/ppc_asm.h>
  11
  12         .align  7
  13 _GLOBAL(__copy_tofrom_user)
  14 BEGIN_FTR_SECTION
  15         nop
  16 FTR_SECTION_ELSE
  17         b       __copy_tofrom_user_power7
  18 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY)
  19 _GLOBAL(__copy_tofrom_user_base)
  20         /* first check for a whole page copy on a page boundary */
  21         cmpldi  cr1,r5,16
  22         cmpdi   cr6,r5,4096
  23         or      r0,r3,r4
  24         neg     r6,r3           /* LS 3 bits = # bytes to 8-byte dest bdry */
  25         andi.   r0,r0,4095
  26         std     r3,-24(r1)
  27         crand   cr0*4+2,cr0*4+2,cr6*4+2
  28         std     r4,-16(r1)
  29         std     r5,-8(r1)
  30         dcbt    0,r4
  31         beq     .Lcopy_page_4K
  32         andi.   r6,r6,7
  33         PPC_MTOCRF(0x01,r5)
  34         blt     cr1,.Lshort_copy
  35 /* Below we want to nop out the bne if we're on a CPU that has the
  36  * CPU_FTR_UNALIGNED_LD_STD bit set and the CPU_FTR_CP_USE_DCBTZ bit
  37  * cleared.
  38  * At the time of writing the only CPU that has this combination of bits
  39  * set is Power6.
  40  */
  41 BEGIN_FTR_SECTION
  42         nop
  43 FTR_SECTION_ELSE
  44         bne     .Ldst_unaligned
  45 ALT_FTR_SECTION_END(CPU_FTR_UNALIGNED_LD_STD | CPU_FTR_CP_USE_DCBTZ, \
  46                     CPU_FTR_UNALIGNED_LD_STD)
  47 .Ldst_aligned:
  48         addi    r3,r3,-16
  49 BEGIN_FTR_SECTION
  50         andi.   r0,r4,7
  51         bne     .Lsrc_unaligned
  52 END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
  53         blt     cr1,.Ldo_tail           /* if < 16 bytes to copy */
  54         srdi    r0,r5,5
  55         cmpdi   cr1,r0,0
  56 20:     ld      r7,0(r4)
  57 220:    ld      r6,8(r4)
  58         addi    r4,r4,16
  59         mtctr   r0
  60         andi.   r0,r5,0x10
  61         beq     22f
  62         addi    r3,r3,16
  63         addi    r4,r4,-16
  64         mr      r9,r7
  65         mr      r8,r6
  66         beq     cr1,72f
  67 21:     ld      r7,16(r4)
  68 221:    ld      r6,24(r4)
  69         addi    r4,r4,32
  70 70:     std     r9,0(r3)
  71 270:    std     r8,8(r3)
  72 22:     ld      r9,0(r4)
  73 222:    ld      r8,8(r4)
  74 71:     std     r7,16(r3)
  75 271:    std     r6,24(r3)
  76         addi    r3,r3,32
  77         bdnz    21b
  78 72:     std     r9,0(r3)
  79 272:    std     r8,8(r3)
  80         andi.   r5,r5,0xf
  81         beq+    3f
  82         addi    r4,r4,16
  83 .Ldo_tail:
  84         addi    r3,r3,16
  85         bf      cr7*4+0,246f
  86 244:    ld      r9,0(r4)
  87         addi    r4,r4,8
  88 245:    std     r9,0(r3)
  89         addi    r3,r3,8
  90 246:    bf      cr7*4+1,1f
  91 23:     lwz     r9,0(r4)
  92         addi    r4,r4,4
  93 73:     stw     r9,0(r3)
  94         addi    r3,r3,4
  95 1:      bf      cr7*4+2,2f
  96 44:     lhz     r9,0(r4)
  97         addi    r4,r4,2
  98 74:     sth     r9,0(r3)
  99         addi    r3,r3,2
 100 2:      bf      cr7*4+3,3f
 101 45:     lbz     r9,0(r4)
 102 75:     stb     r9,0(r3)
 103 3:      li      r3,0
 104         blr
 105
 106 .Lsrc_unaligned:
 107         srdi    r6,r5,3
 108         addi    r5,r5,-16
 109         subf    r4,r0,r4
 110         srdi    r7,r5,4
 111         sldi    r10,r0,3
 112         cmpldi  cr6,r6,3
 113         andi.   r5,r5,7
 114         mtctr   r7
 115         subfic  r11,r10,64
 116         add     r5,r5,r0
 117         bt      cr7*4+0,28f
 118
 119 24:     ld      r9,0(r4)        /* 3+2n loads, 2+2n stores */
 120 25:     ld      r0,8(r4)
 121         sld     r6,r9,r10
 122 26:     ldu     r9,16(r4)
 123         srd     r7,r0,r11
 124         sld     r8,r0,r10
 125         or      r7,r7,r6
 126         blt     cr6,79f
 127 27:     ld      r0,8(r4)
 128         b       2f
 129
 130 28:     ld      r0,0(r4)        /* 4+2n loads, 3+2n stores */
 131 29:     ldu     r9,8(r4)
 132         sld     r8,r0,r10
 133         addi    r3,r3,-8
 134         blt     cr6,5f
 135 30:     ld      r0,8(r4)
 136         srd     r12,r9,r11
 137         sld     r6,r9,r10
 138 31:     ldu     r9,16(r4)
 139         or      r12,r8,r12
 140         srd     r7,r0,r11
 141         sld     r8,r0,r10
 142         addi    r3,r3,16
 143         beq     cr6,78f
 144
 145 1:      or      r7,r7,r6
 146 32:     ld      r0,8(r4)
 147 76:     std     r12,8(r3)
 148 2:      srd     r12,r9,r11
 149         sld     r6,r9,r10
 150 33:     ldu     r9,16(r4)
 151         or      r12,r8,r12
 152 77:     stdu    r7,16(r3)
 153         srd     r7,r0,r11
 154         sld     r8,r0,r10
 155         bdnz    1b
 156
 157 78:     std     r12,8(r3)
 158         or      r7,r7,r6
 159 79:     std     r7,16(r3)
 160 5:      srd     r12,r9,r11
 161         or      r12,r8,r12
 162 80:     std     r12,24(r3)
 163         bne     6f
 164         li      r3,0
 165         blr
 166 6:      cmpwi   cr1,r5,8
 167         addi    r3,r3,32
 168         sld     r9,r9,r10
 169         ble     cr1,7f
 170 34:     ld      r0,8(r4)
 171         srd     r7,r0,r11
 172         or      r9,r7,r9
 173 7:
 174         bf      cr7*4+1,1f
 175         rotldi  r9,r9,32
 176 94:     stw     r9,0(r3)
 177         addi    r3,r3,4
 178 1:      bf      cr7*4+2,2f
 179         rotldi  r9,r9,16
 180 95:     sth     r9,0(r3)
 181         addi    r3,r3,2
 182 2:      bf      cr7*4+3,3f
 183         rotldi  r9,r9,8
 184 96:     stb     r9,0(r3)
 185 3:      li      r3,0
 186         blr
 187
 188 .Ldst_unaligned:
 189         PPC_MTOCRF(0x01,r6)             /* put #bytes to 8B bdry into cr7 */
 190         subf    r5,r6,r5
 191         li      r7,0
 192         cmpldi  cr1,r5,16
 193         bf      cr7*4+3,1f
 194 35:     lbz     r0,0(r4)
 195 81:     stb     r0,0(r3)
 196         addi    r7,r7,1
 197 1:      bf      cr7*4+2,2f
 198 36:     lhzx    r0,r7,r4
 199 82:     sthx    r0,r7,r3
 200         addi    r7,r7,2
 201 2:      bf      cr7*4+1,3f
 202 37:     lwzx    r0,r7,r4
 203 83:     stwx    r0,r7,r3
 204 3:      PPC_MTOCRF(0x01,r5)
 205         add     r4,r6,r4
 206         add     r3,r6,r3
 207         b       .Ldst_aligned
 208
 209 .Lshort_copy:
 210         bf      cr7*4+0,1f
 211 38:     lwz     r0,0(r4)
 212 39:     lwz     r9,4(r4)
 213         addi    r4,r4,8
 214 84:     stw     r0,0(r3)
 215 85:     stw     r9,4(r3)
 216         addi    r3,r3,8
 217 1:      bf      cr7*4+1,2f
 218 40:     lwz     r0,0(r4)
 219         addi    r4,r4,4
 220 86:     stw     r0,0(r3)
 221         addi    r3,r3,4
 222 2:      bf      cr7*4+2,3f
 223 41:     lhz     r0,0(r4)
 224         addi    r4,r4,2
 225 87:     sth     r0,0(r3)
 226         addi    r3,r3,2
 227 3:      bf      cr7*4+3,4f
 228 42:     lbz     r0,0(r4)
 229 88:     stb     r0,0(r3)
 230 4:      li      r3,0
 231         blr
 232
 233 /*
 234  * exception handlers follow
 235  * we have to return the number of bytes not copied
 236  * for an exception on a load, we set the rest of the destination to 0
 237  */
 238
 239 136:
 240 137:
 241         add     r3,r3,r7
 242         b       1f
 243 130:
 244 131:
 245         addi    r3,r3,8
 246 120:
 247 320:
 248 122:
 249 322:
 250 124:
 251 125:
 252 126:
 253 127:
 254 128:
 255 129:
 256 133:
 257         addi    r3,r3,8
 258 132:
 259         addi    r3,r3,8
 260 121:
 261 321:
 262 344:
 263 134:
 264 135:
 265 138:
 266 139:
 267 140:
 268 141:
 269 142:
 270 123:
 271 144:
 272 145:
 273
 274 /*
 275  * here we have had a fault on a load and r3 points to the first
 276  * unmodified byte of the destination
 277  */
 278 1:      ld      r6,-24(r1)
 279         ld      r4,-16(r1)
 280         ld      r5,-8(r1)
 281         subf    r6,r6,r3
 282         add     r4,r4,r6
 283         subf    r5,r6,r5        /* #bytes left to go */
 284
 285 /*
 286  * first see if we can copy any more bytes before hitting another exception
 287  */
 288         mtctr   r5
 289 43:     lbz     r0,0(r4)
 290         addi    r4,r4,1
 291 89:     stb     r0,0(r3)
 292         addi    r3,r3,1
 293         bdnz    43b
 294         li      r3,0            /* huh? all copied successfully this time? */
 295         blr
 296
 297 /*
 298  * here we have trapped again, need to clear ctr bytes starting at r3
 299  */
 300 143:    mfctr   r5
 301         li      r0,0
 302         mr      r4,r3
 303         mr      r3,r5           /* return the number of bytes not copied */
 304 1:      andi.   r9,r4,7
 305         beq     3f
 306 90:     stb     r0,0(r4)
 307         addic.  r5,r5,-1
 308         addi    r4,r4,1
 309         bne     1b
 310         blr
 311 3:      cmpldi  cr1,r5,8
 312         srdi    r9,r5,3
 313         andi.   r5,r5,7
 314         blt     cr1,93f
 315         mtctr   r9
 316 91:     std     r0,0(r4)
 317         addi    r4,r4,8
 318         bdnz    91b
 319 93:     beqlr
 320         mtctr   r5
 321 92:     stb     r0,0(r4)
 322         addi    r4,r4,1
 323         bdnz    92b
 324         blr
 325
 326 /*
 327  * exception handlers for stores: we just need to work
 328  * out how many bytes weren't copied
 329  */
 330 182:
 331 183:
 332         add     r3,r3,r7
 333         b       1f
 334 371:
 335 180:
 336         addi    r3,r3,8
 337 171:
 338 177:
 339         addi    r3,r3,8
 340 370:
 341 372:
 342 176:
 343 178:
 344         addi    r3,r3,4
 345 185:
 346         addi    r3,r3,4
 347 170:
 348 172:
 349 345:
 350 173:
 351 174:
 352 175:
 353 179:
 354 181:
 355 184:
 356 186:
 357 187:
 358 188:
 359 189:
 360 194:
 361 195:
 362 196:
 363 1:
 364         ld      r6,-24(r1)
 365         ld      r5,-8(r1)
 366         add     r6,r6,r5
 367         subf    r3,r3,r6        /* #bytes not copied */
 368 190:
 369 191:
 370 192:
 371         blr                     /* #bytes not copied in r3 */
 372
 373         .section __ex_table,"a"
 374         .align  3
 375         .llong  20b,120b
 376         .llong  220b,320b
 377         .llong  21b,121b
 378         .llong  221b,321b
 379         .llong  70b,170b
 380         .llong  270b,370b
 381         .llong  22b,122b
 382         .llong  222b,322b
 383         .llong  71b,171b
 384         .llong  271b,371b
 385         .llong  72b,172b
 386         .llong  272b,372b
 387         .llong  244b,344b
 388         .llong  245b,345b
 389         .llong  23b,123b
 390         .llong  73b,173b
 391         .llong  44b,144b
 392         .llong  74b,174b
 393         .llong  45b,145b
 394         .llong  75b,175b
 395         .llong  24b,124b
 396         .llong  25b,125b
 397         .llong  26b,126b
 398         .llong  27b,127b
 399         .llong  28b,128b
 400         .llong  29b,129b
 401         .llong  30b,130b
 402         .llong  31b,131b
 403         .llong  32b,132b
 404         .llong  76b,176b
 405         .llong  33b,133b
 406         .llong  77b,177b
 407         .llong  78b,178b
 408         .llong  79b,179b
 409         .llong  80b,180b
 410         .llong  34b,134b
 411         .llong  94b,194b
 412         .llong  95b,195b
 413         .llong  96b,196b
 414         .llong  35b,135b
 415         .llong  81b,181b
 416         .llong  36b,136b
 417         .llong  82b,182b
 418         .llong  37b,137b
 419         .llong  83b,183b
 420         .llong  38b,138b
 421         .llong  39b,139b
 422         .llong  84b,184b
 423         .llong  85b,185b
 424         .llong  40b,140b
 425         .llong  86b,186b
 426         .llong  41b,141b
 427         .llong  87b,187b
 428         .llong  42b,142b
 429         .llong  88b,188b
 430         .llong  43b,143b
 431         .llong  89b,189b
 432         .llong  90b,190b
 433         .llong  91b,191b
 434         .llong  92b,192b
 435
 436         .text
 437
 438 /*
 439  * Routine to copy a whole page of data, optimized for POWER4.
 440  * On POWER4 it is more than 50% faster than the simple loop
 441  * above (following the .Ldst_aligned label) but it runs slightly
 442  * slower on POWER3.
 443  */
 444 .Lcopy_page_4K:
 445         std     r31,-32(1)
 446         std     r30,-40(1)
 447         std     r29,-48(1)
 448         std     r28,-56(1)
 449         std     r27,-64(1)
 450         std     r26,-72(1)
 451         std     r25,-80(1)
 452         std     r24,-88(1)
 453         std     r23,-96(1)
 454         std     r22,-104(1)
 455         std     r21,-112(1)
 456         std     r20,-120(1)
 457         li      r5,4096/32 - 1
 458         addi    r3,r3,-8
 459         li      r0,5
 460 0:      addi    r5,r5,-24
 461         mtctr   r0
 462 20:     ld      r22,640(4)
 463 21:     ld      r21,512(4)
 464 22:     ld      r20,384(4)
 465 23:     ld      r11,256(4)
 466 24:     ld      r9,128(4)
 467 25:     ld      r7,0(4)
 468 26:     ld      r25,648(4)
 469 27:     ld      r24,520(4)
 470 28:     ld      r23,392(4)
 471 29:     ld      r10,264(4)
 472 30:     ld      r8,136(4)
 473 31:     ldu     r6,8(4)
 474         cmpwi   r5,24
 475 1:
 476 32:     std     r22,648(3)
 477 33:     std     r21,520(3)
 478 34:     std     r20,392(3)
 479 35:     std     r11,264(3)
 480 36:     std     r9,136(3)
 481 37:     std     r7,8(3)
 482 38:     ld      r28,648(4)
 483 39:     ld      r27,520(4)
 484 40:     ld      r26,392(4)
 485 41:     ld      r31,264(4)
 486 42:     ld      r30,136(4)
 487 43:     ld      r29,8(4)
 488 44:     std     r25,656(3)
 489 45:     std     r24,528(3)
 490 46:     std     r23,400(3)
 491 47:     std     r10,272(3)
 492 48:     std     r8,144(3)
 493 49:     std     r6,16(3)
 494 50:     ld      r22,656(4)
 495 51:     ld      r21,528(4)
 496 52:     ld      r20,400(4)
 497 53:     ld      r11,272(4)
 498 54:     ld      r9,144(4)
 499 55:     ld      r7,16(4)
 500 56:     std     r28,664(3)
 501 57:     std     r27,536(3)
 502 58:     std     r26,408(3)
 503 59:     std     r31,280(3)
 504 60:     std     r30,152(3)
 505 61:     stdu    r29,24(3)
 506 62:     ld      r25,664(4)
 507 63:     ld      r24,536(4)
 508 64:     ld      r23,408(4)
 509 65:     ld      r10,280(4)
 510 66:     ld      r8,152(4)
 511 67:     ldu     r6,24(4)
 512         bdnz    1b
 513 68:     std     r22,648(3)
 514 69:     std     r21,520(3)
 515 70:     std     r20,392(3)
 516 71:     std     r11,264(3)
 517 72:     std     r9,136(3)
 518 73:     std     r7,8(3)
 519 74:     addi    r4,r4,640
 520 75:     addi    r3,r3,648
 521         bge     0b
 522         mtctr   r5
 523 76:     ld      r7,0(4)
 524 77:     ld      r8,8(4)
 525 78:     ldu     r9,16(4)
 526 3:
 527 79:     ld      r10,8(4)
 528 80:     std     r7,8(3)
 529 81:     ld      r7,16(4)
 530 82:     std     r8,16(3)
 531 83:     ld      r8,24(4)
 532 84:     std     r9,24(3)
 533 85:     ldu     r9,32(4)
 534 86:     stdu    r10,32(3)
 535         bdnz    3b
 536 4:
 537 87:     ld      r10,8(4)
 538 88:     std     r7,8(3)
 539 89:     std     r8,16(3)
 540 90:     std     r9,24(3)
 541 91:     std     r10,32(3)
 542 9:      ld      r20,-120(1)
 543         ld      r21,-112(1)
 544         ld      r22,-104(1)
 545         ld      r23,-96(1)
 546         ld      r24,-88(1)
 547         ld      r25,-80(1)
 548         ld      r26,-72(1)
 549         ld      r27,-64(1)
 550         ld      r28,-56(1)
 551         ld      r29,-48(1)
 552         ld      r30,-40(1)
 553         ld      r31,-32(1)
 554         li      r3,0
 555         blr
 556
 557 /*
 558  * on an exception, reset to the beginning and jump back into the
 559  * standard __copy_tofrom_user
 560  */
 561 100:    ld      r20,-120(1)
 562         ld      r21,-112(1)
 563         ld      r22,-104(1)
 564         ld      r23,-96(1)
 565         ld      r24,-88(1)
 566         ld      r25,-80(1)
 567         ld      r26,-72(1)
 568         ld      r27,-64(1)
 569         ld      r28,-56(1)
 570         ld      r29,-48(1)
 571         ld      r30,-40(1)
 572         ld      r31,-32(1)
 573         ld      r3,-24(r1)
 574         ld      r4,-16(r1)
 575         li      r5,4096
 576         b       .Ldst_aligned
 577
 578         .section __ex_table,"a"
 579         .align  3
 580         .llong  20b,100b
 581         .llong  21b,100b
 582         .llong  22b,100b
 583         .llong  23b,100b
 584         .llong  24b,100b
 585         .llong  25b,100b
 586         .llong  26b,100b
 587         .llong  27b,100b
 588         .llong  28b,100b
 589         .llong  29b,100b
 590         .llong  30b,100b
 591         .llong  31b,100b
 592         .llong  32b,100b
 593         .llong  33b,100b
 594         .llong  34b,100b
 595         .llong  35b,100b
 596         .llong  36b,100b
 597         .llong  37b,100b
 598         .llong  38b,100b
 599         .llong  39b,100b
 600         .llong  40b,100b
 601         .llong  41b,100b
 602         .llong  42b,100b
 603         .llong  43b,100b
 604         .llong  44b,100b
 605         .llong  45b,100b
 606         .llong  46b,100b
 607         .llong  47b,100b
 608         .llong  48b,100b
 609         .llong  49b,100b
 610         .llong  50b,100b
 611         .llong  51b,100b
 612         .llong  52b,100b
 613         .llong  53b,100b
 614         .llong  54b,100b
 615         .llong  55b,100b
 616         .llong  56b,100b
 617         .llong  57b,100b
 618         .llong  58b,100b
 619         .llong  59b,100b
 620         .llong  60b,100b
 621         .llong  61b,100b
 622         .llong  62b,100b
 623         .llong  63b,100b
 624         .llong  64b,100b
 625         .llong  65b,100b
 626         .llong  66b,100b
 627         .llong  67b,100b
 628         .llong  68b,100b
 629         .llong  69b,100b
 630         .llong  70b,100b
 631         .llong  71b,100b
 632         .llong  72b,100b
 633         .llong  73b,100b
 634         .llong  74b,100b
 635         .llong  75b,100b
 636         .llong  76b,100b
 637         .llong  77b,100b
 638         .llong  78b,100b
 639         .llong  79b,100b
 640         .llong  80b,100b
 641         .llong  81b,100b
 642         .llong  82b,100b
 643         .llong  83b,100b
 644         .llong  84b,100b
 645         .llong  85b,100b
 646         .llong  86b,100b
 647         .llong  87b,100b
 648         .llong  88b,100b
 649         .llong  89b,100b
 650         .llong  90b,100b
 651         .llong  91b,100b