1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
4 */
5
6 /*
7 * Description
8 *
9 * library function for memcpy where length bytes are copied from
10 * ptr_in to ptr_out. ptr_out is returned unchanged.
11 * Allows any combination of alignment on input and output pointers
12 * and length from 0 to 2^32-1
13 *
14 * Restrictions
15 * The arrays should not overlap, the program will produce undefined output
16 * if they do.
17 * For blocks less than 16 bytes a byte by byte copy is performed. For
18 * 8byte alignments, and length multiples, a dword copy is performed up to
19 * 96bytes
20 * History
21 *
22 * DJH 5/15/09 Initial version 1.0
23 * DJH 6/ 1/09 Version 1.1 modified ABI to inlcude R16-R19
24 * DJH 7/12/09 Version 1.2 optimized codesize down to 760 was 840
25 * DJH 10/14/09 Version 1.3 added special loop for aligned case, was
26 * overreading bloated codesize back up to 892
27 * DJH 4/20/10 Version 1.4 fixed Ldword_loop_epilog loop to prevent loads
28 * occurring if only 1 left outstanding, fixes bug
29 * # 3888, corrected for all alignments. Peeled off
30 * 1 32byte chunk from kernel loop and extended 8byte
31 * loop at end to solve all combinations and prevent
32 * over read. Fixed Ldword_loop_prolog to prevent
33 * overread for blocks less than 48bytes. Reduced
34 * codesize to 752 bytes
35 * DJH 4/21/10 version 1.5 1.4 fix broke code for input block ends not
36 * aligned to dword boundaries,underwriting by 1
37 * byte, added detection for this and fixed. A
38 * little bloat.
39 * DJH 4/23/10 version 1.6 corrected stack error, R20 was not being restored
40 * always, fixed the error of R20 being modified
41 * before it was being saved
42 * Natural c model
43 * ===============
44 * void * memcpy(char * ptr_out, char * ptr_in, int length) {
45 * int i;
46 * if(length) for(i=0; i < length; i++) { ptr_out[i] = ptr_in[i]; }
47 * return(ptr_out);
48 * }
49 *
50 * Optimized memcpy function
51 * =========================
52 * void * memcpy(char * ptr_out, char * ptr_in, int len) {
53 * int i, prolog, kernel, epilog, mask;
54 * u8 offset;
55 * s64 data0, dataF8, data70;
56 *
57 * s64 * ptr8_in;
58 * s64 * ptr8_out;
59 * s32 * ptr4;
60 * s16 * ptr2;
61 *
62 * offset = ((int) ptr_in) & 7;
63 * ptr8_in = (s64 *) &ptr_in[-offset]; //read in the aligned pointers
64 *
65 * data70 = *ptr8_in++;
66 * dataF8 = *ptr8_in++;
67 *
68 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
69 *
70 * prolog = 32 - ((int) ptr_out);
71 * mask = 0x7fffffff >> HEXAGON_R_cl0_R(len);
72 * prolog = prolog & mask;
73 * kernel = len - prolog;
74 * epilog = kernel & 0x1F;
75 * kernel = kernel>>5;
76 *
77 * if (prolog & 1) { ptr_out[0] = (u8) data0; data0 >>= 8; ptr_out += 1;}
78 * ptr2 = (s16 *) &ptr_out[0];
79 * if (prolog & 2) { ptr2[0] = (u16) data0; data0 >>= 16; ptr_out += 2;}
80 * ptr4 = (s32 *) &ptr_out[0];
81 * if (prolog & 4) { ptr4[0] = (u32) data0; data0 >>= 32; ptr_out += 4;}
82 *
83 * offset = offset + (prolog & 7);
84 * if (offset >= 8) {
85 * data70 = dataF8;
86 * dataF8 = *ptr8_in++;
87 * }
88 * offset = offset & 0x7;
89 *
90 * prolog = prolog >> 3;
91 * if (prolog) for (i=0; i < prolog; i++) {
92 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
93 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
94 * data70 = dataF8;
95 * dataF8 = *ptr8_in++;
96 * }
97 * if(kernel) { kernel -= 1; epilog += 32; }
98 * if(kernel) for(i=0; i < kernel; i++) {
99 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
100 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
101 * data70 = *ptr8_in++;
102 *
103 * data0 = HEXAGON_P_valignb_PPp(data70, dataF8, offset);
104 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
105 * dataF8 = *ptr8_in++;
106 *
107 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
108 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
109 * data70 = *ptr8_in++;
110 *
111 * data0 = HEXAGON_P_valignb_PPp(data70, dataF8, offset);
112 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
113 * dataF8 = *ptr8_in++;
114 * }
115 * epilogdws = epilog >> 3;
116 * if (epilogdws) for (i=0; i < epilogdws; i++) {
117 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
118 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
119 * data70 = dataF8;
120 * dataF8 = *ptr8_in++;
121 * }
122 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
123 *
124 * ptr4 = (s32 *) &ptr_out[0];
125 * if (epilog & 4) { ptr4[0] = (u32) data0; data0 >>= 32; ptr_out += 4;}
126 * ptr2 = (s16 *) &ptr_out[0];
127 * if (epilog & 2) { ptr2[0] = (u16) data0; data0 >>= 16; ptr_out += 2;}
128 * if (epilog & 1) { *ptr_out++ = (u8) data0; }
129 *
130 * return(ptr_out - length);
131 * }
132 *
133 * Codesize : 784 bytes
134 */
135
136
137 #define ptr_out R0 /* destination pounter */
138 #define ptr_in R1 /* source pointer */
139 #define len R2 /* length of copy in bytes */
140
141 #define data70 R13:12 /* lo 8 bytes of non-aligned transfer */
142 #define dataF8 R11:10 /* hi 8 bytes of non-aligned transfer */
143 #define ldata0 R7:6 /* even 8 bytes chunks */
144 #define ldata1 R25:24 /* odd 8 bytes chunks */
145 #define data1 R7 /* lower 8 bytes of ldata1 */
146 #define data0 R6 /* lower 8 bytes of ldata0 */
147
148 #define ifbyte p0 /* if transfer has bytes in epilog/prolog */
149 #define ifhword p0 /* if transfer has shorts in epilog/prolog */
150 #define ifword p0 /* if transfer has words in epilog/prolog */
151 #define noprolog p0 /* no prolog, xfer starts at 32byte */
152 #define nokernel p1 /* no 32byte multiple block in the transfer */
153 #define noepilog p0 /* no epilog, xfer ends on 32byte boundary */
154 #define align p2 /* alignment of input rel to 8byte boundary */
155 #define kernel1 p0 /* kernel count == 1 */
156
157 #define dalign R25 /* rel alignment of input to output data */
158 #define star3 R16 /* number bytes in prolog - dwords */
159 #define rest R8 /* length - prolog bytes */
160 #define back R7 /* nr bytes > dword boundary in src block */
161 #define epilog R3 /* bytes in epilog */
162 #define inc R15:14 /* inc kernel by -1 and defetch ptr by 32 */
163 #define kernel R4 /* number of 32byte chunks in kernel */
164 #define ptr_in_p_128 R5 /* pointer for prefetch of input data */
165 #define mask R8 /* mask used to determine prolog size */
166 #define shift R8 /* used to work a shifter to extract bytes */
167 #define shift2 R5 /* in epilog to workshifter to extract bytes */
168 #define prolog R15 /* bytes in prolog */
169 #define epilogdws R15 /* number dwords in epilog */
170 #define shiftb R14 /* used to extract bytes */
171 #define offset R9 /* same as align in reg */
172 #define ptr_out_p_32 R17 /* pointer to output dczero */
173 #define align888 R14 /* if simple dword loop can be used */
174 #define len8 R9 /* number of dwords in length */
175 #define over R20 /* nr of bytes > last inp buf dword boundary */
176
177 #define ptr_in_p_128kernel R5:4 /* packed fetch pointer & kernel cnt */
178
179 .section .text
180 .p2align 4
181 .global memcpy
182 .type memcpy, @function
183 memcpy:
184 {
185 p2 = cmp.eq(len, #0); /* =0 */
186 align888 = or(ptr_in, ptr_out); /* %8 < 97 */
187 p0 = cmp.gtu(len, #23); /* %1, <24 */
188 p1 = cmp.eq(ptr_in, ptr_out); /* attempt to overwrite self */
189 }
190 {
191 p1 = or(p2, p1);
192 p3 = cmp.gtu(len, #95); /* %8 < 97 */
193 align888 = or(align888, len); /* %8 < 97 */
194 len8 = lsr(len, #3); /* %8 < 97 */
195 }
196 {
197 dcfetch(ptr_in); /* zero/ptrin=ptrout causes fetch */
198 p2 = bitsclr(align888, #7); /* %8 < 97 */
199 if(p1) jumpr r31; /* =0 */
200 }
201 {
202 p2 = and(p2,!p3); /* %8 < 97 */
203 if (p2.new) len = add(len, #-8); /* %8 < 97 */
204 if (p2.new) jump:NT .Ldwordaligned; /* %8 < 97 */
205 }
206 {
207 if(!p0) jump .Lbytes23orless; /* %1, <24 */
208 mask.l = #LO(0x7fffffff);
209 /* all bytes before line multiples of data */
210 prolog = sub(#0, ptr_out);
211 }
212 {
213 /* save r31 on stack, decrement sp by 16 */
214 allocframe(#24);
215 mask.h = #HI(0x7fffffff);
216 ptr_in_p_128 = add(ptr_in, #32);
217 back = cl0(len);
218 }
219 {
220 memd(sp+#0) = R17:16; /* save r16,r17 on stack6 */
221 r31.l = #LO(.Lmemcpy_return); /* set up final return pointer */
222 prolog &= lsr(mask, back);
223 offset = and(ptr_in, #7);
224 }
225 {
226 memd(sp+#8) = R25:24; /* save r25,r24 on stack */
227 dalign = sub(ptr_out, ptr_in);
228 r31.h = #HI(.Lmemcpy_return); /* set up final return pointer */
229 }
230 {
231 /* see if there if input buffer end if aligned */
232 over = add(len, ptr_in);
233 back = add(len, offset);
234 memd(sp+#16) = R21:20; /* save r20,r21 on stack */
235 }
236 {
237 noprolog = bitsclr(prolog, #7);
238 prolog = and(prolog, #31);
239 dcfetch(ptr_in_p_128);
240 ptr_in_p_128 = add(ptr_in_p_128, #32);
241 }
242 {
243 kernel = sub(len, prolog);
244 shift = asl(prolog, #3);
245 star3 = and(prolog, #7);
246 ptr_in = and(ptr_in, #-8);
247 }
248 {
249 prolog = lsr(prolog, #3);
250 epilog = and(kernel, #31);
251 ptr_out_p_32 = add(ptr_out, prolog);
252 over = and(over, #7);
253 }
254 {
255 p3 = cmp.gtu(back, #8);
256 kernel = lsr(kernel, #5);
257 dcfetch(ptr_in_p_128);
258 ptr_in_p_128 = add(ptr_in_p_128, #32);
259 }
260 {
261 p1 = cmp.eq(prolog, #0);
262 if(!p1.new) prolog = add(prolog, #1);
263 dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
264 ptr_in_p_128 = add(ptr_in_p_128, #32);
265 }
266 {
267 nokernel = cmp.eq(kernel,#0);
268 dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
269 ptr_in_p_128 = add(ptr_in_p_128, #32);
270 shiftb = and(shift, #8);
271 }
272 {
273 dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
274 ptr_in_p_128 = add(ptr_in_p_128, #32);
275 if(nokernel) jump .Lskip64;
276 p2 = cmp.eq(kernel, #1); /* skip ovr if kernel == 0 */
277 }
278 {
279 dczeroa(ptr_out_p_32);
280 /* don't advance pointer */
281 if(!p2) ptr_out_p_32 = add(ptr_out_p_32, #32);
282 }
283 {
284 dalign = and(dalign, #31);
285 dczeroa(ptr_out_p_32);
286 }
287 .Lskip64:
288 {
289 data70 = memd(ptr_in++#16);
290 if(p3) dataF8 = memd(ptr_in+#8);
291 if(noprolog) jump .Lnoprolog32;
292 align = offset;
293 }
294 /* upto initial 7 bytes */
295 {
296 ldata0 = valignb(dataF8, data70, align);
297 ifbyte = tstbit(shift,#3);
298 offset = add(offset, star3);
299 }
300 {
301 if(ifbyte) memb(ptr_out++#1) = data0;
302 ldata0 = lsr(ldata0, shiftb);
303 shiftb = and(shift, #16);
304 ifhword = tstbit(shift,#4);
305 }
306 {
307 if(ifhword) memh(ptr_out++#2) = data0;
308 ldata0 = lsr(ldata0, shiftb);
309 ifword = tstbit(shift,#5);
310 p2 = cmp.gtu(offset, #7);
311 }
312 {
313 if(ifword) memw(ptr_out++#4) = data0;
314 if(p2) data70 = dataF8;
315 if(p2) dataF8 = memd(ptr_in++#8); /* another 8 bytes */
316 align = offset;
317 }
318 .Lnoprolog32:
319 {
320 p3 = sp1loop0(.Ldword_loop_prolog, prolog)
321 rest = sub(len, star3); /* whats left after the loop */
322 p0 = cmp.gt(over, #0);
323 }
324 if(p0) rest = add(rest, #16);
325 .Ldword_loop_prolog:
326 {
327 if(p3) memd(ptr_out++#8) = ldata0;
328 ldata0 = valignb(dataF8, data70, align);
329 p0 = cmp.gt(rest, #16);
330 }
331 {
332 data70 = dataF8;
333 if(p0) dataF8 = memd(ptr_in++#8);
334 rest = add(rest, #-8);
335 }:endloop0
336 .Lkernel:
337 {
338 /* kernel is at least 32bytes */
339 p3 = cmp.gtu(kernel, #0);
340 /* last itn. remove edge effects */
341 if(p3.new) kernel = add(kernel, #-1);
342 /* dealt with in last dword loop */
343 if(p3.new) epilog = add(epilog, #32);
344 }
345 {
346 nokernel = cmp.eq(kernel, #0); /* after adjustment, recheck */
347 if(nokernel.new) jump:NT .Lepilog; /* likely not taken */
348 inc = combine(#32, #-1);
349 p3 = cmp.gtu(dalign, #24);
350 }
351 {
352 if(p3) jump .Lodd_alignment;
353 }
354 {
355 loop0(.Loword_loop_25to31, kernel);
356 kernel1 = cmp.gtu(kernel, #1);
357 rest = kernel;
358 }
359 .falign
360 .Loword_loop_25to31:
361 {
362 dcfetch(ptr_in_p_128); /* prefetch 4 lines ahead */
363 if(kernel1) ptr_out_p_32 = add(ptr_out_p_32, #32);
364 }
365 {
366 dczeroa(ptr_out_p_32); /* reserve the next 32bytes in cache */
367 p3 = cmp.eq(kernel, rest);
368 }
369 {
370 /* kernel -= 1 */
371 ptr_in_p_128kernel = vaddw(ptr_in_p_128kernel, inc);
372 /* kill write on first iteration */
373 if(!p3) memd(ptr_out++#8) = ldata1;
374 ldata1 = valignb(dataF8, data70, align);
375 data70 = memd(ptr_in++#8);
376 }
377 {
378 memd(ptr_out++#8) = ldata0;
379 ldata0 = valignb(data70, dataF8, align);
380 dataF8 = memd(ptr_in++#8);
381 }
382 {
383 memd(ptr_out++#8) = ldata1;
384 ldata1 = valignb(dataF8, data70, align);
385 data70 = memd(ptr_in++#8);
386 }
387 {
388 memd(ptr_out++#8) = ldata0;
389 ldata0 = valignb(data70, dataF8, align);
390 dataF8 = memd(ptr_in++#8);
391 kernel1 = cmp.gtu(kernel, #1);
392 }:endloop0
393 {
394 memd(ptr_out++#8) = ldata1;
395 jump .Lepilog;
396 }
397 .Lodd_alignment:
398 {
399 loop0(.Loword_loop_00to24, kernel);
400 kernel1 = cmp.gtu(kernel, #1);
401 rest = add(kernel, #-1);
402 }
403 .falign
404 .Loword_loop_00to24:
405 {
406 dcfetch(ptr_in_p_128); /* prefetch 4 lines ahead */
407 ptr_in_p_128kernel = vaddw(ptr_in_p_128kernel, inc);
408 if(kernel1) ptr_out_p_32 = add(ptr_out_p_32, #32);
409 }
410 {
411 dczeroa(ptr_out_p_32); /* reserve the next 32bytes in cache */
412 }
413 {
414 memd(ptr_out++#8) = ldata0;
415 ldata0 = valignb(dataF8, data70, align);
416 data70 = memd(ptr_in++#8);
417 }
418 {
419 memd(ptr_out++#8) = ldata0;
420 ldata0 = valignb(data70, dataF8, align);
421 dataF8 = memd(ptr_in++#8);
422 }
423 {
424 memd(ptr_out++#8) = ldata0;
425 ldata0 = valignb(dataF8, data70, align);
426 data70 = memd(ptr_in++#8);
427 }
428 {
429 memd(ptr_out++#8) = ldata0;
430 ldata0 = valignb(data70, dataF8, align);
431 dataF8 = memd(ptr_in++#8);
432 kernel1 = cmp.gtu(kernel, #1);
433 }:endloop0
434 .Lepilog:
435 {
436 noepilog = cmp.eq(epilog,#0);
437 epilogdws = lsr(epilog, #3);
438 kernel = and(epilog, #7);
439 }
440 {
441 if(noepilog) jumpr r31;
442 if(noepilog) ptr_out = sub(ptr_out, len);
443 p3 = cmp.eq(epilogdws, #0);
444 shift2 = asl(epilog, #3);
445 }
446 {
447 shiftb = and(shift2, #32);
448 ifword = tstbit(epilog,#2);
449 if(p3) jump .Lepilog60;
450 if(!p3) epilog = add(epilog, #-16);
451 }
452 {
453 loop0(.Ldword_loop_epilog, epilogdws);
454 /* stop criteria is lsbs unless = 0 then its 8 */
455 p3 = cmp.eq(kernel, #0);
456 if(p3.new) kernel= #8;
457 p1 = cmp.gt(over, #0);
458 }
459 /* if not aligned to end of buffer execute 1 more iteration */
460 if(p1) kernel= #0;
461 .Ldword_loop_epilog:
462 {
463 memd(ptr_out++#8) = ldata0;
464 ldata0 = valignb(dataF8, data70, align);
465 p3 = cmp.gt(epilog, kernel);
466 }
467 {
468 data70 = dataF8;
469 if(p3) dataF8 = memd(ptr_in++#8);
470 epilog = add(epilog, #-8);
471 }:endloop0
472 /* copy last 7 bytes */
473 .Lepilog60:
474 {
475 if(ifword) memw(ptr_out++#4) = data0;
476 ldata0 = lsr(ldata0, shiftb);
477 ifhword = tstbit(epilog,#1);
478 shiftb = and(shift2, #16);
479 }
480 {
481 if(ifhword) memh(ptr_out++#2) = data0;
482 ldata0 = lsr(ldata0, shiftb);
483 ifbyte = tstbit(epilog,#0);
484 if(ifbyte.new) len = add(len, #-1);
485 }
486 {
487 if(ifbyte) memb(ptr_out) = data0;
488 ptr_out = sub(ptr_out, len); /* return dest pointer */
489 jumpr r31;
490 }
491 /* do byte copy for small n */
492 .Lbytes23orless:
493 {
494 p3 = sp1loop0(.Lbyte_copy, len);
495 len = add(len, #-1);
496 }
497 .Lbyte_copy:
498 {
499 data0 = memb(ptr_in++#1);
500 if(p3) memb(ptr_out++#1) = data0;
501 }:endloop0
502 {
503 memb(ptr_out) = data0;
504 ptr_out = sub(ptr_out, len);
505 jumpr r31;
506 }
507 /* do dword copies for aligned in, out and length */
508 .Ldwordaligned:
509 {
510 p3 = sp1loop0(.Ldword_copy, len8);
511 }
512 .Ldword_copy:
513 {
514 if(p3) memd(ptr_out++#8) = ldata0;
515 ldata0 = memd(ptr_in++#8);
516 }:endloop0
517 {
518 memd(ptr_out) = ldata0;
519 ptr_out = sub(ptr_out, len);
520 jumpr r31; /* return to function caller */
521 }
522 .Lmemcpy_return:
523 r21:20 = memd(sp+#16); /* restore r20+r21 */
524 {
525 r25:24 = memd(sp+#8); /* restore r24+r25 */
526 r17:16 = memd(sp+#0); /* restore r16+r17 */
527 }
528 deallocframe; /* restore r31 and incrment stack by 16 */
529 jumpr r31
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