1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Memory copy functions for 32-bit PowerPC.
4 *
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 */
7#include <linux/export.h>
8#include <asm/processor.h>
9#include <asm/cache.h>
10#include <asm/errno.h>
11#include <asm/ppc_asm.h>
12#include <asm/code-patching-asm.h>
13#include <asm/kasan.h>
14
15#define COPY_16_BYTES \
16 lwz r7,4(r4); \
17 lwz r8,8(r4); \
18 lwz r9,12(r4); \
19 lwzu r10,16(r4); \
20 stw r7,4(r6); \
21 stw r8,8(r6); \
22 stw r9,12(r6); \
23 stwu r10,16(r6)
24
25#define COPY_16_BYTES_WITHEX(n) \
268 ## n ## 0: \
27 lwz r7,4(r4); \
288 ## n ## 1: \
29 lwz r8,8(r4); \
308 ## n ## 2: \
31 lwz r9,12(r4); \
328 ## n ## 3: \
33 lwzu r10,16(r4); \
348 ## n ## 4: \
35 stw r7,4(r6); \
368 ## n ## 5: \
37 stw r8,8(r6); \
388 ## n ## 6: \
39 stw r9,12(r6); \
408 ## n ## 7: \
41 stwu r10,16(r6)
42
43#define COPY_16_BYTES_EXCODE(n) \
449 ## n ## 0: \
45 addi r5,r5,-(16 * n); \
46 b 104f; \
479 ## n ## 1: \
48 addi r5,r5,-(16 * n); \
49 b 105f; \
50 EX_TABLE(8 ## n ## 0b,9 ## n ## 0b); \
51 EX_TABLE(8 ## n ## 1b,9 ## n ## 0b); \
52 EX_TABLE(8 ## n ## 2b,9 ## n ## 0b); \
53 EX_TABLE(8 ## n ## 3b,9 ## n ## 0b); \
54 EX_TABLE(8 ## n ## 4b,9 ## n ## 1b); \
55 EX_TABLE(8 ## n ## 5b,9 ## n ## 1b); \
56 EX_TABLE(8 ## n ## 6b,9 ## n ## 1b); \
57 EX_TABLE(8 ## n ## 7b,9 ## n ## 1b)
58
59 .text
60
61CACHELINE_BYTES = L1_CACHE_BYTES
62LG_CACHELINE_BYTES = L1_CACHE_SHIFT
63CACHELINE_MASK = (L1_CACHE_BYTES-1)
64
65#ifndef CONFIG_KASAN
66_GLOBAL(memset16)
67 rlwinm. r0 ,r5, 31, 1, 31
68 addi r6, r3, -4
69 beq- 2f
70 rlwimi r4 ,r4 ,16 ,0 ,15
71 mtctr r0
721: stwu r4, 4(r6)
73 bdnz 1b
742: andi. r0, r5, 1
75 beqlr
76 sth r4, 4(r6)
77 blr
78EXPORT_SYMBOL(memset16)
79#endif
80
81/*
82 * Use dcbz on the complete cache lines in the destination
83 * to set them to zero. This requires that the destination
84 * area is cacheable. -- paulus
85 *
86 * During early init, cache might not be active yet, so dcbz cannot be used.
87 * We therefore skip the optimised bloc that uses dcbz. This jump is
88 * replaced by a nop once cache is active. This is done in machine_init()
89 */
90_GLOBAL_KASAN(memset)
91 cmplwi 0,r5,4
92 blt 7f
93
94 rlwimi r4,r4,8,16,23
95 rlwimi r4,r4,16,0,15
96
97 stw r4,0(r3)
98 beqlr
99 andi. r0,r3,3
100 add r5,r0,r5
101 subf r6,r0,r3
102 cmplwi 0,r4,0
103 /*
104 * Skip optimised bloc until cache is enabled. Will be replaced
105 * by 'bne' during boot to use normal procedure if r4 is not zero
106 */
1075: b 2f
108 patch_site 5b, patch__memset_nocache
109
110 clrlwi r7,r6,32-LG_CACHELINE_BYTES
111 add r8,r7,r5
112 srwi r9,r8,LG_CACHELINE_BYTES
113 addic. r9,r9,-1 /* total number of complete cachelines */
114 ble 2f
115 xori r0,r7,CACHELINE_MASK & ~3
116 srwi. r0,r0,2
117 beq 3f
118 mtctr r0
1194: stwu r4,4(r6)
120 bdnz 4b
1213: mtctr r9
122 li r7,4
12310: dcbz r7,r6
124 addi r6,r6,CACHELINE_BYTES
125 bdnz 10b
126 clrlwi r5,r8,32-LG_CACHELINE_BYTES
127 addi r5,r5,4
128
1292: srwi r0,r5,2
130 mtctr r0
131 bdz 6f
1321: stwu r4,4(r6)
133 bdnz 1b
1346: andi. r5,r5,3
135 beqlr
136 mtctr r5
137 addi r6,r6,3
1388: stbu r4,1(r6)
139 bdnz 8b
140 blr
141
1427: cmpwi 0,r5,0
143 beqlr
144 mtctr r5
145 addi r6,r3,-1
1469: stbu r4,1(r6)
147 bdnz 9b
148 blr
149EXPORT_SYMBOL(memset)
150EXPORT_SYMBOL_KASAN(memset)
151
152/*
153 * This version uses dcbz on the complete cache lines in the
154 * destination area to reduce memory traffic. This requires that
155 * the destination area is cacheable.
156 * We only use this version if the source and dest don't overlap.
157 * -- paulus.
158 *
159 * During early init, cache might not be active yet, so dcbz cannot be used.
160 * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is
161 * replaced by a nop once cache is active. This is done in machine_init()
162 */
163_GLOBAL_KASAN(memmove)
164 cmplw 0,r3,r4
165 bgt backwards_memcpy
166 /* fall through */
167
168_GLOBAL_KASAN(memcpy)
1691: b generic_memcpy
170 patch_site 1b, patch__memcpy_nocache
171
172 add r7,r3,r5 /* test if the src & dst overlap */
173 add r8,r4,r5
174 cmplw 0,r4,r7
175 cmplw 1,r3,r8
176 crand 0,0,4 /* cr0.lt &= cr1.lt */
177 blt generic_memcpy /* if regions overlap */
178
179 addi r4,r4,-4
180 addi r6,r3,-4
181 neg r0,r3
182 andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */
183 beq 58f
184
185 cmplw 0,r5,r0 /* is this more than total to do? */
186 blt 63f /* if not much to do */
187 andi. r8,r0,3 /* get it word-aligned first */
188 subf r5,r0,r5
189 mtctr r8
190 beq+ 61f
19170: lbz r9,4(r4) /* do some bytes */
192 addi r4,r4,1
193 addi r6,r6,1
194 stb r9,3(r6)
195 bdnz 70b
19661: srwi. r0,r0,2
197 mtctr r0
198 beq 58f
19972: lwzu r9,4(r4) /* do some words */
200 stwu r9,4(r6)
201 bdnz 72b
202
20358: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
204 clrlwi r5,r5,32-LG_CACHELINE_BYTES
205 li r11,4
206 mtctr r0
207 beq 63f
20853:
209 dcbz r11,r6
210 COPY_16_BYTES
211#if L1_CACHE_BYTES >= 32
212 COPY_16_BYTES
213#if L1_CACHE_BYTES >= 64
214 COPY_16_BYTES
215 COPY_16_BYTES
216#if L1_CACHE_BYTES >= 128
217 COPY_16_BYTES
218 COPY_16_BYTES
219 COPY_16_BYTES
220 COPY_16_BYTES
221#endif
222#endif
223#endif
224 bdnz 53b
225
22663: srwi. r0,r5,2
227 mtctr r0
228 beq 64f
22930: lwzu r0,4(r4)
230 stwu r0,4(r6)
231 bdnz 30b
232
23364: andi. r0,r5,3
234 mtctr r0
235 beq+ 65f
236 addi r4,r4,3
237 addi r6,r6,3
23840: lbzu r0,1(r4)
239 stbu r0,1(r6)
240 bdnz 40b
24165: blr
242EXPORT_SYMBOL(memcpy)
243EXPORT_SYMBOL(memmove)
244EXPORT_SYMBOL_KASAN(memcpy)
245EXPORT_SYMBOL_KASAN(memmove)
246
247generic_memcpy:
248 srwi. r7,r5,3
249 addi r6,r3,-4
250 addi r4,r4,-4
251 beq 2f /* if less than 8 bytes to do */
252 andi. r0,r6,3 /* get dest word aligned */
253 mtctr r7
254 bne 5f
2551: lwz r7,4(r4)
256 lwzu r8,8(r4)
257 stw r7,4(r6)
258 stwu r8,8(r6)
259 bdnz 1b
260 andi. r5,r5,7
2612: cmplwi 0,r5,4
262 blt 3f
263 lwzu r0,4(r4)
264 addi r5,r5,-4
265 stwu r0,4(r6)
2663: cmpwi 0,r5,0
267 beqlr
268 mtctr r5
269 addi r4,r4,3
270 addi r6,r6,3
2714: lbzu r0,1(r4)
272 stbu r0,1(r6)
273 bdnz 4b
274 blr
2755: subfic r0,r0,4
276 mtctr r0
2776: lbz r7,4(r4)
278 addi r4,r4,1
279 stb r7,4(r6)
280 addi r6,r6,1
281 bdnz 6b
282 subf r5,r0,r5
283 rlwinm. r7,r5,32-3,3,31
284 beq 2b
285 mtctr r7
286 b 1b
287
288_GLOBAL(backwards_memcpy)
289 rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */
290 add r6,r3,r5
291 add r4,r4,r5
292 beq 2f
293 andi. r0,r6,3
294 mtctr r7
295 bne 5f
2961: lwz r7,-4(r4)
297 lwzu r8,-8(r4)
298 stw r7,-4(r6)
299 stwu r8,-8(r6)
300 bdnz 1b
301 andi. r5,r5,7
3022: cmplwi 0,r5,4
303 blt 3f
304 lwzu r0,-4(r4)
305 subi r5,r5,4
306 stwu r0,-4(r6)
3073: cmpwi 0,r5,0
308 beqlr
309 mtctr r5
3104: lbzu r0,-1(r4)
311 stbu r0,-1(r6)
312 bdnz 4b
313 blr
3145: mtctr r0
3156: lbzu r7,-1(r4)
316 stbu r7,-1(r6)
317 bdnz 6b
318 subf r5,r0,r5
319 rlwinm. r7,r5,32-3,3,31
320 beq 2b
321 mtctr r7
322 b 1b
323
324_GLOBAL(__copy_tofrom_user)
325 addi r4,r4,-4
326 addi r6,r3,-4
327 neg r0,r3
328 andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */
329 beq 58f
330
331 cmplw 0,r5,r0 /* is this more than total to do? */
332 blt 63f /* if not much to do */
333 andi. r8,r0,3 /* get it word-aligned first */
334 mtctr r8
335 beq+ 61f
33670: lbz r9,4(r4) /* do some bytes */
33771: stb r9,4(r6)
338 addi r4,r4,1
339 addi r6,r6,1
340 bdnz 70b
34161: subf r5,r0,r5
342 srwi. r0,r0,2
343 mtctr r0
344 beq 58f
34572: lwzu r9,4(r4) /* do some words */
34673: stwu r9,4(r6)
347 bdnz 72b
348
349 EX_TABLE(70b,100f)
350 EX_TABLE(71b,101f)
351 EX_TABLE(72b,102f)
352 EX_TABLE(73b,103f)
353
35458: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
355 clrlwi r5,r5,32-LG_CACHELINE_BYTES
356 li r11,4
357 beq 63f
358
359 /* Here we decide how far ahead to prefetch the source */
360 li r3,4
361 cmpwi r0,1
362 li r7,0
363 ble 114f
364 li r7,1
365#if MAX_COPY_PREFETCH > 1
366 /* Heuristically, for large transfers we prefetch
367 MAX_COPY_PREFETCH cachelines ahead. For small transfers
368 we prefetch 1 cacheline ahead. */
369 cmpwi r0,MAX_COPY_PREFETCH
370 ble 112f
371 li r7,MAX_COPY_PREFETCH
372112: mtctr r7
373111: dcbt r3,r4
374 addi r3,r3,CACHELINE_BYTES
375 bdnz 111b
376#else
377 dcbt r3,r4
378 addi r3,r3,CACHELINE_BYTES
379#endif /* MAX_COPY_PREFETCH > 1 */
380
381114: subf r8,r7,r0
382 mr r0,r7
383 mtctr r8
384
38553: dcbt r3,r4
38654: dcbz r11,r6
387 EX_TABLE(54b,105f)
388/* the main body of the cacheline loop */
389 COPY_16_BYTES_WITHEX(0)
390#if L1_CACHE_BYTES >= 32
391 COPY_16_BYTES_WITHEX(1)
392#if L1_CACHE_BYTES >= 64
393 COPY_16_BYTES_WITHEX(2)
394 COPY_16_BYTES_WITHEX(3)
395#if L1_CACHE_BYTES >= 128
396 COPY_16_BYTES_WITHEX(4)
397 COPY_16_BYTES_WITHEX(5)
398 COPY_16_BYTES_WITHEX(6)
399 COPY_16_BYTES_WITHEX(7)
400#endif
401#endif
402#endif
403 bdnz 53b
404 cmpwi r0,0
405 li r3,4
406 li r7,0
407 bne 114b
408
40963: srwi. r0,r5,2
410 mtctr r0
411 beq 64f
41230: lwzu r0,4(r4)
41331: stwu r0,4(r6)
414 bdnz 30b
415
41664: andi. r0,r5,3
417 mtctr r0
418 beq+ 65f
41940: lbz r0,4(r4)
42041: stb r0,4(r6)
421 addi r4,r4,1
422 addi r6,r6,1
423 bdnz 40b
42465: li r3,0
425 blr
426
427/* read fault, initial single-byte copy */
428100: li r9,0
429 b 90f
430/* write fault, initial single-byte copy */
431101: li r9,1
43290: subf r5,r8,r5
433 li r3,0
434 b 99f
435/* read fault, initial word copy */
436102: li r9,0
437 b 91f
438/* write fault, initial word copy */
439103: li r9,1
44091: li r3,2
441 b 99f
442
443/*
444 * this stuff handles faults in the cacheline loop and branches to either
445 * 104f (if in read part) or 105f (if in write part), after updating r5
446 */
447 COPY_16_BYTES_EXCODE(0)
448#if L1_CACHE_BYTES >= 32
449 COPY_16_BYTES_EXCODE(1)
450#if L1_CACHE_BYTES >= 64
451 COPY_16_BYTES_EXCODE(2)
452 COPY_16_BYTES_EXCODE(3)
453#if L1_CACHE_BYTES >= 128
454 COPY_16_BYTES_EXCODE(4)
455 COPY_16_BYTES_EXCODE(5)
456 COPY_16_BYTES_EXCODE(6)
457 COPY_16_BYTES_EXCODE(7)
458#endif
459#endif
460#endif
461
462/* read fault in cacheline loop */
463104: li r9,0
464 b 92f
465/* fault on dcbz (effectively a write fault) */
466/* or write fault in cacheline loop */
467105: li r9,1
46892: li r3,LG_CACHELINE_BYTES
469 mfctr r8
470 add r0,r0,r8
471 b 106f
472/* read fault in final word loop */
473108: li r9,0
474 b 93f
475/* write fault in final word loop */
476109: li r9,1
47793: andi. r5,r5,3
478 li r3,2
479 b 99f
480/* read fault in final byte loop */
481110: li r9,0
482 b 94f
483/* write fault in final byte loop */
484111: li r9,1
48594: li r5,0
486 li r3,0
487/*
488 * At this stage the number of bytes not copied is
489 * r5 + (ctr << r3), and r9 is 0 for read or 1 for write.
490 */
49199: mfctr r0
492106: slw r3,r0,r3
493 add. r3,r3,r5
494 beq 120f /* shouldn't happen */
495 cmpwi 0,r9,0
496 bne 120f
497/* for a read fault, first try to continue the copy one byte at a time */
498 mtctr r3
499130: lbz r0,4(r4)
500131: stb r0,4(r6)
501 addi r4,r4,1
502 addi r6,r6,1
503 bdnz 130b
504/* then clear out the destination: r3 bytes starting at 4(r6) */
505132: mfctr r3
506120: blr
507
508 EX_TABLE(30b,108b)
509 EX_TABLE(31b,109b)
510 EX_TABLE(40b,110b)
511 EX_TABLE(41b,111b)
512 EX_TABLE(130b,132b)
513 EX_TABLE(131b,120b)
514
515EXPORT_SYMBOL(__copy_tofrom_user)
516

source code of linux/arch/powerpc/lib/copy_32.S