Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
os
linux
1/*
2 * String handling functions for PowerPC.
3 *
4 * Copyright (C) 1996 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#include <linux/config.h>
12#include <asm/processor.h>
13#include <asm/cache.h>
14#include <asm/errno.h>
15#include <asm/ppc_asm.h>
16
17#define COPY_16_BYTES \
18 lwz r7,4(r4); \
19 lwz r8,8(r4); \
20 lwz r9,12(r4); \
21 lwzu r10,16(r4); \
22 stw r7,4(r6); \
23 stw r8,8(r6); \
24 stw r9,12(r6); \
25 stwu r10,16(r6)
26
27#define COPY_16_BYTES_WITHEX(n) \
288 ## n ## 0: \
29 lwz r7,4(r4); \
308 ## n ## 1: \
31 lwz r8,8(r4); \
328 ## n ## 2: \
33 lwz r9,12(r4); \
348 ## n ## 3: \
35 lwzu r10,16(r4); \
368 ## n ## 4: \
37 stw r7,4(r6); \
388 ## n ## 5: \
39 stw r8,8(r6); \
408 ## n ## 6: \
41 stw r9,12(r6); \
428 ## n ## 7: \
43 stwu r10,16(r6)
44
45#define COPY_16_BYTES_EXCODE(n) \
469 ## n ## 0: \
47 addi r5,r5,-(16 * n); \
48 b 104f; \
499 ## n ## 1: \
50 addi r5,r5,-(16 * n); \
51 b 105f; \
52.section __ex_table,"a"; \
53 .align 2; \
54 .long 8 ## n ## 0b,9 ## n ## 0b; \
55 .long 8 ## n ## 1b,9 ## n ## 0b; \
56 .long 8 ## n ## 2b,9 ## n ## 0b; \
57 .long 8 ## n ## 3b,9 ## n ## 0b; \
58 .long 8 ## n ## 4b,9 ## n ## 1b; \
59 .long 8 ## n ## 5b,9 ## n ## 1b; \
60 .long 8 ## n ## 6b,9 ## n ## 1b; \
61 .long 8 ## n ## 7b,9 ## n ## 1b; \
62 .text
63
64 .text
65 .stabs "arch/ppc/lib/",N_SO,0,0,0f
66 .stabs "string.S",N_SO,0,0,0f
67
68CACHELINE_BYTES = L1_CACHE_BYTES
69LG_CACHELINE_BYTES = L1_CACHE_SHIFT
70CACHELINE_MASK = (L1_CACHE_BYTES-1)
71
72_GLOBAL(strcpy)
73 addi r5,r3,-1
74 addi r4,r4,-1
751: lbzu r0,1(r4)
76 cmpwi 0,r0,0
77 stbu r0,1(r5)
78 bne 1b
79 blr
80
81/* This clears out any unused part of the destination buffer,
82 just as the libc version does. -- paulus */
83_GLOBAL(strncpy)
84 cmpwi 0,r5,0
85 beqlr
86 mtctr r5
87 addi r6,r3,-1
88 addi r4,r4,-1
891: lbzu r0,1(r4)
90 cmpwi 0,r0,0
91 stbu r0,1(r6)
92 bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */
93 bnelr /* if we didn't hit a null char, we're done */
94 mfctr r5
95 cmpwi 0,r5,0 /* any space left in destination buffer? */
96 beqlr /* we know r0 == 0 here */
972: stbu r0,1(r6) /* clear it out if so */
98 bdnz 2b
99 blr
100
101_GLOBAL(strcat)
102 addi r5,r3,-1
103 addi r4,r4,-1
1041: lbzu r0,1(r5)
105 cmpwi 0,r0,0
106 bne 1b
107 addi r5,r5,-1
1081: lbzu r0,1(r4)
109 cmpwi 0,r0,0
110 stbu r0,1(r5)
111 bne 1b
112 blr
113
114_GLOBAL(strcmp)
115 addi r5,r3,-1
116 addi r4,r4,-1
1171: lbzu r3,1(r5)
118 cmpwi 1,r3,0
119 lbzu r0,1(r4)
120 subf. r3,r0,r3
121 beqlr 1
122 beq 1b
123 blr
124
125_GLOBAL(strlen)
126 addi r4,r3,-1
1271: lbzu r0,1(r4)
128 cmpwi 0,r0,0
129 bne 1b
130 subf r3,r3,r4
131 blr
132
133/*
134 * Use dcbz on the complete cache lines in the destination
135 * to set them to zero. This requires that the destination
136 * area is cacheable. -- paulus
137 */
138_GLOBAL(cacheable_memzero)
139 mr r5,r4
140 li r4,0
141 addi r6,r3,-4
142 cmplwi 0,r5,4
143 blt 7f
144 stwu r4,4(r6)
145 beqlr
146 andi. r0,r6,3
147 add r5,r0,r5
148 subf r6,r0,r6
149 clrlwi r7,r6,32-LG_CACHELINE_BYTES
150 add r8,r7,r5
151 srwi r9,r8,LG_CACHELINE_BYTES
152 addic. r9,r9,-1 /* total number of complete cachelines */
153 ble 2f
154 xori r0,r7,CACHELINE_MASK & ~3
155 srwi. r0,r0,2
156 beq 3f
157 mtctr r0
1584: stwu r4,4(r6)
159 bdnz 4b
1603: mtctr r9
161 li r7,4
162#if !defined(CONFIG_8xx)
16310: dcbz r7,r6
164#else
16510: stw r4, 4(r6)
166 stw r4, 8(r6)
167 stw r4, 12(r6)
168 stw r4, 16(r6)
169#if CACHE_LINE_SIZE >= 32
170 stw r4, 20(r6)
171 stw r4, 24(r6)
172 stw r4, 28(r6)
173 stw r4, 32(r6)
174#endif /* CACHE_LINE_SIZE */
175#endif
176 addi r6,r6,CACHELINE_BYTES
177 bdnz 10b
178 clrlwi r5,r8,32-LG_CACHELINE_BYTES
179 addi r5,r5,4
1802: srwi r0,r5,2
181 mtctr r0
182 bdz 6f
1831: stwu r4,4(r6)
184 bdnz 1b
1856: andi. r5,r5,3
1867: cmpwi 0,r5,0
187 beqlr
188 mtctr r5
189 addi r6,r6,3
1908: stbu r4,1(r6)
191 bdnz 8b
192 blr
193
194_GLOBAL(memset)
195 rlwimi r4,r4,8,16,23
196 rlwimi r4,r4,16,0,15
197 addi r6,r3,-4
198 cmplwi 0,r5,4
199 blt 7f
200 stwu r4,4(r6)
201 beqlr
202 andi. r0,r6,3
203 add r5,r0,r5
204 subf r6,r0,r6
205 srwi r0,r5,2
206 mtctr r0
207 bdz 6f
2081: stwu r4,4(r6)
209 bdnz 1b
2106: andi. r5,r5,3
2117: cmpwi 0,r5,0
212 beqlr
213 mtctr r5
214 addi r6,r6,3
2158: stbu r4,1(r6)
216 bdnz 8b
217 blr
218
219/*
220 * This version uses dcbz on the complete cache lines in the
221 * destination area to reduce memory traffic. This requires that
222 * the destination area is cacheable.
223 * We only use this version if the source and dest don't overlap.
224 * -- paulus.
225 */
226_GLOBAL(cacheable_memcpy)
227 add r7,r3,r5 /* test if the src & dst overlap */
228 add r8,r4,r5
229 cmplw 0,r4,r7
230 cmplw 1,r3,r8
231 crand 0,0,4 /* cr0.lt &= cr1.lt */
232 blt memcpy /* if regions overlap */
233
234 addi r4,r4,-4
235 addi r6,r3,-4
236 neg r0,r3
237 andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */
238 beq 58f
239
240 cmplw 0,r5,r0 /* is this more than total to do? */
241 blt 63f /* if not much to do */
242 andi. r8,r0,3 /* get it word-aligned first */
243 subf r5,r0,r5
244 mtctr r8
245 beq+ 61f
24670: lbz r9,4(r4) /* do some bytes */
247 stb r9,4(r6)
248 addi r4,r4,1
249 addi r6,r6,1
250 bdnz 70b
25161: srwi. r0,r0,2
252 mtctr r0
253 beq 58f
25472: lwzu r9,4(r4) /* do some words */
255 stwu r9,4(r6)
256 bdnz 72b
257
25858: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
259 clrlwi r5,r5,32-LG_CACHELINE_BYTES
260 li r11,4
261 mtctr r0
262 beq 63f
26353:
264#if !defined(CONFIG_8xx)
265 dcbz r11,r6
266#endif
267 COPY_16_BYTES
268#if L1_CACHE_BYTES >= 32
269 COPY_16_BYTES
270#if L1_CACHE_BYTES >= 64
271 COPY_16_BYTES
272 COPY_16_BYTES
273#if L1_CACHE_BYTES >= 128
274 COPY_16_BYTES
275 COPY_16_BYTES
276 COPY_16_BYTES
277 COPY_16_BYTES
278#endif
279#endif
280#endif
281 bdnz 53b
282
28363: srwi. r0,r5,2
284 mtctr r0
285 beq 64f
28630: lwzu r0,4(r4)
287 stwu r0,4(r6)
288 bdnz 30b
289
29064: andi. r0,r5,3
291 mtctr r0
292 beq+ 65f
29340: lbz r0,4(r4)
294 stb r0,4(r6)
295 addi r4,r4,1
296 addi r6,r6,1
297 bdnz 40b
29865: blr
299
300_GLOBAL(memmove)
301 cmplw 0,r3,r4
302 bgt backwards_memcpy
303 /* fall through */
304
305_GLOBAL(memcpy)
306 srwi. r7,r5,3
307 addi r6,r3,-4
308 addi r4,r4,-4
309 beq 2f /* if less than 8 bytes to do */
310 andi. r0,r6,3 /* get dest word aligned */
311 mtctr r7
312 bne 5f
3131: lwz r7,4(r4)
314 lwzu r8,8(r4)
315 stw r7,4(r6)
316 stwu r8,8(r6)
317 bdnz 1b
318 andi. r5,r5,7
3192: cmplwi 0,r5,4
320 blt 3f
321 lwzu r0,4(r4)
322 addi r5,r5,-4
323 stwu r0,4(r6)
3243: cmpwi 0,r5,0
325 beqlr
326 mtctr r5
327 addi r4,r4,3
328 addi r6,r6,3
3294: lbzu r0,1(r4)
330 stbu r0,1(r6)
331 bdnz 4b
332 blr
3335: subfic r0,r0,4
334 mtctr r0
3356: lbz r7,4(r4)
336 addi r4,r4,1
337 stb r7,4(r6)
338 addi r6,r6,1
339 bdnz 6b
340 subf r5,r0,r5
341 rlwinm. r7,r5,32-3,3,31
342 beq 2b
343 mtctr r7
344 b 1b
345
346_GLOBAL(backwards_memcpy)
347 rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */
348 add r6,r3,r5
349 add r4,r4,r5
350 beq 2f
351 andi. r0,r6,3
352 mtctr r7
353 bne 5f
3541: lwz r7,-4(r4)
355 lwzu r8,-8(r4)
356 stw r7,-4(r6)
357 stwu r8,-8(r6)
358 bdnz 1b
359 andi. r5,r5,7
3602: cmplwi 0,r5,4
361 blt 3f
362 lwzu r0,-4(r4)
363 subi r5,r5,4
364 stwu r0,-4(r6)
3653: cmpwi 0,r5,0
366 beqlr
367 mtctr r5
3684: lbzu r0,-1(r4)
369 stbu r0,-1(r6)
370 bdnz 4b
371 blr
3725: mtctr r0
3736: lbzu r7,-1(r4)
374 stbu r7,-1(r6)
375 bdnz 6b
376 subf r5,r0,r5
377 rlwinm. r7,r5,32-3,3,31
378 beq 2b
379 mtctr r7
380 b 1b
381
382_GLOBAL(memcmp)
383 cmpwi 0,r5,0
384 ble- 2f
385 mtctr r5
386 addi r6,r3,-1
387 addi r4,r4,-1
3881: lbzu r3,1(r6)
389 lbzu r0,1(r4)
390 subf. r3,r0,r3
391 bdnzt 2,1b
392 blr
3932: li r3,0
394 blr
395
396_GLOBAL(memchr)
397 cmpwi 0,r5,0
398 ble- 2f
399 mtctr r5
400 addi r3,r3,-1
4011: lbzu r0,1(r3)
402 cmpw 0,r0,r4
403 bdnzf 2,1b
404 beqlr
4052: li r3,0
406 blr
407
408_GLOBAL(__copy_tofrom_user)
409 addi r4,r4,-4
410 addi r6,r3,-4
411 neg r0,r3
412 andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */
413 beq 58f
414
415 cmplw 0,r5,r0 /* is this more than total to do? */
416 blt 63f /* if not much to do */
417 andi. r8,r0,3 /* get it word-aligned first */
418 mtctr r8
419 beq+ 61f
42070: lbz r9,4(r4) /* do some bytes */
42171: stb r9,4(r6)
422 addi r4,r4,1
423 addi r6,r6,1
424 bdnz 70b
42561: subf r5,r0,r5
426 srwi. r0,r0,2
427 mtctr r0
428 beq 58f
42972: lwzu r9,4(r4) /* do some words */
43073: stwu r9,4(r6)
431 bdnz 72b
432
433 .section __ex_table,"a"
434 .align 2
435 .long 70b,100f
436 .long 71b,101f
437 .long 72b,102f
438 .long 73b,103f
439 .text
440
44158: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
442 clrlwi r5,r5,32-LG_CACHELINE_BYTES
443 li r11,4
444 beq 63f
445
446#ifdef CONFIG_8xx
447 /* Don't use prefetch on 8xx */
448 mtctr r0
449 li r0,0
45053: COPY_16_BYTES_WITHEX(0)
451 bdnz 53b
452
453#else /* not CONFIG_8xx */
454 /* Here we decide how far ahead to prefetch the source */
455 li r3,4
456 cmpwi r0,1
457 li r7,0
458 ble 114f
459 li r7,1
460#if MAX_COPY_PREFETCH > 1
461 /* Heuristically, for large transfers we prefetch
462 MAX_COPY_PREFETCH cachelines ahead. For small transfers
463 we prefetch 1 cacheline ahead. */
464 cmpwi r0,MAX_COPY_PREFETCH
465 ble 112f
466 li r7,MAX_COPY_PREFETCH
467112: mtctr r7
468111: dcbt r3,r4
469 addi r3,r3,CACHELINE_BYTES
470 bdnz 111b
471#else
472 dcbt r3,r4
473 addi r3,r3,CACHELINE_BYTES
474#endif /* MAX_COPY_PREFETCH > 1 */
475
476114: subf r8,r7,r0
477 mr r0,r7
478 mtctr r8
479
48053: dcbt r3,r4
48154: dcbz r11,r6
482 .section __ex_table,"a"
483 .align 2
484 .long 54b,105f
485 .text
486/* the main body of the cacheline loop */
487 COPY_16_BYTES_WITHEX(0)
488#if L1_CACHE_BYTES >= 32
489 COPY_16_BYTES_WITHEX(1)
490#if L1_CACHE_BYTES >= 64
491 COPY_16_BYTES_WITHEX(2)
492 COPY_16_BYTES_WITHEX(3)
493#if L1_CACHE_BYTES >= 128
494 COPY_16_BYTES_WITHEX(4)
495 COPY_16_BYTES_WITHEX(5)
496 COPY_16_BYTES_WITHEX(6)
497 COPY_16_BYTES_WITHEX(7)
498#endif
499#endif
500#endif
501 bdnz 53b
502 cmpwi r0,0
503 li r3,4
504 li r7,0
505 bne 114b
506#endif /* CONFIG_8xx */
507
50863: srwi. r0,r5,2
509 mtctr r0
510 beq 64f
51130: lwzu r0,4(r4)
51231: stwu r0,4(r6)
513 bdnz 30b
514
51564: andi. r0,r5,3
516 mtctr r0
517 beq+ 65f
51840: lbz r0,4(r4)
51941: stb r0,4(r6)
520 addi r4,r4,1
521 addi r6,r6,1
522 bdnz 40b
52365: li r3,0
524 blr
525
526/* read fault, initial single-byte copy */
527100: li r9,0
528 b 90f
529/* write fault, initial single-byte copy */
530101: li r9,1
53190: subf r5,r8,r5
532 li r3,0
533 b 99f
534/* read fault, initial word copy */
535102: li r9,0
536 b 91f
537/* write fault, initial word copy */
538103: li r9,1
53991: li r3,2
540 b 99f
541
542/*
543 * this stuff handles faults in the cacheline loop and branches to either
544 * 104f (if in read part) or 105f (if in write part), after updating r5
545 */
546 COPY_16_BYTES_EXCODE(0)
547#if L1_CACHE_BYTES >= 32
548 COPY_16_BYTES_EXCODE(1)
549#if L1_CACHE_BYTES >= 64
550 COPY_16_BYTES_EXCODE(2)
551 COPY_16_BYTES_EXCODE(3)
552#if L1_CACHE_BYTES >= 128
553 COPY_16_BYTES_EXCODE(4)
554 COPY_16_BYTES_EXCODE(5)
555 COPY_16_BYTES_EXCODE(6)
556 COPY_16_BYTES_EXCODE(7)
557#endif
558#endif
559#endif
560
561/* read fault in cacheline loop */
562104: li r9,0
563 b 92f
564/* fault on dcbz (effectively a write fault) */
565/* or write fault in cacheline loop */
566105: li r9,1
56792: li r3,LG_CACHELINE_BYTES
568 mfctr r8
569 add r0,r0,r8
570 b 106f
571/* read fault in final word loop */
572108: li r9,0
573 b 93f
574/* write fault in final word loop */
575109: li r9,1
57693: andi. r5,r5,3
577 li r3,2
578 b 99f
579/* read fault in final byte loop */
580110: li r9,0
581 b 94f
582/* write fault in final byte loop */
583111: li r9,1
58494: li r5,0
585 li r3,0
586/*
587 * At this stage the number of bytes not copied is
588 * r5 + (ctr << r3), and r9 is 0 for read or 1 for write.
589 */
59099: mfctr r0
591106: slw r3,r0,r3
592 add. r3,r3,r5
593 beq 120f /* shouldn't happen */
594 cmpwi 0,r9,0
595 bne 120f
596/* for a read fault, first try to continue the copy one byte at a time */
597 mtctr r3
598130: lbz r0,4(r4)
599131: stb r0,4(r6)
600 addi r4,r4,1
601 addi r6,r6,1
602 bdnz 130b
603/* then clear out the destination: r3 bytes starting at 4(r6) */
604132: mfctr r3
605 srwi. r0,r3,2
606 li r9,0
607 mtctr r0
608 beq 113f
609112: stwu r9,4(r6)
610 bdnz 112b
611113: andi. r0,r3,3
612 mtctr r0
613 beq 120f
614114: stb r9,4(r6)
615 addi r6,r6,1
616 bdnz 114b
617120: blr
618
619 .section __ex_table,"a"
620 .align 2
621 .long 30b,108b
622 .long 31b,109b
623 .long 40b,110b
624 .long 41b,111b
625 .long 130b,132b
626 .long 131b,120b
627 .long 112b,120b
628 .long 114b,120b
629 .text
630
631_GLOBAL(__clear_user)
632 addi r6,r3,-4
633 li r3,0
634 li r5,0
635 cmplwi 0,r4,4
636 blt 7f
637 /* clear a single word */
63811: stwu r5,4(r6)
639 beqlr
640 /* clear word sized chunks */
641 andi. r0,r6,3
642 add r4,r0,r4
643 subf r6,r0,r6
644 srwi r0,r4,2
645 andi. r4,r4,3
646 mtctr r0
647 bdz 7f
6481: stwu r5,4(r6)
649 bdnz 1b
650 /* clear byte sized chunks */
6517: cmpwi 0,r4,0
652 beqlr
653 mtctr r4
654 addi r6,r6,3
6558: stbu r5,1(r6)
656 bdnz 8b
657 blr
65890: mr r3,r4
659 blr
66091: mfctr r3
661 slwi r3,r3,2
662 add r3,r3,r4
663 blr
66492: mfctr r3
665 blr
666
667 .section __ex_table,"a"
668 .align 2
669 .long 11b,90b
670 .long 1b,91b
671 .long 8b,92b
672 .text
673
674_GLOBAL(__strncpy_from_user)
675 addi r6,r3,-1
676 addi r4,r4,-1
677 cmpwi 0,r5,0
678 beq 2f
679 mtctr r5
6801: lbzu r0,1(r4)
681 cmpwi 0,r0,0
682 stbu r0,1(r6)
683 bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */
684 beq 3f
6852: addi r6,r6,1
6863: subf r3,r3,r6
687 blr
68899: li r3,-EFAULT
689 blr
690
691 .section __ex_table,"a"
692 .align 2
693 .long 1b,99b
694 .text
695
696/* r3 = str, r4 = len (> 0), r5 = top (highest addr) */
697_GLOBAL(__strnlen_user)
698 addi r7,r3,-1
699 subf r6,r7,r5 /* top+1 - str */
700 cmplw 0,r4,r6
701 bge 0f
702 mr r6,r4
7030: mtctr r6 /* ctr = min(len, top - str) */
7041: lbzu r0,1(r7) /* get next byte */
705 cmpwi 0,r0,0
706 bdnzf 2,1b /* loop if --ctr != 0 && byte != 0 */
707 addi r7,r7,1
708 subf r3,r3,r7 /* number of bytes we have looked at */
709 beqlr /* return if we found a 0 byte */
710 cmpw 0,r3,r4 /* did we look at all len bytes? */
711 blt 99f /* if not, must have hit top */
712 addi r3,r4,1 /* return len + 1 to indicate no null found */
713 blr
71499: li r3,0 /* bad address, return 0 */
715 blr
716
717 .section __ex_table,"a"
718 .align 2
719 .long 1b,99b