1/* SPDX-License-Identifier: GPL-2.0 */ 2/* checksum.S: Sparc optimized checksum code. 3 * 4 * Copyright(C) 1995 Linus Torvalds 5 * Copyright(C) 1995 Miguel de Icaza 6 * Copyright(C) 1996 David S. Miller 7 * Copyright(C) 1997 Jakub Jelinek 8 * 9 * derived from: 10 * Linux/Alpha checksum c-code 11 * Linux/ix86 inline checksum assembly 12 * RFC1071 Computing the Internet Checksum (esp. Jacobsons m68k code) 13 * David Mosberger-Tang for optimized reference c-code 14 * BSD4.4 portable checksum routine 15 */ 16 17#include <asm/errno.h> 18#include <asm/export.h> 19 20#define CSUM_BIGCHUNK(buf, offset, sum, t0, t1, t2, t3, t4, t5) \ 21 ldd [buf + offset + 0x00], t0; \ 22 ldd [buf + offset + 0x08], t2; \ 23 addxcc t0, sum, sum; \ 24 addxcc t1, sum, sum; \ 25 ldd [buf + offset + 0x10], t4; \ 26 addxcc t2, sum, sum; \ 27 addxcc t3, sum, sum; \ 28 ldd [buf + offset + 0x18], t0; \ 29 addxcc t4, sum, sum; \ 30 addxcc t5, sum, sum; \ 31 addxcc t0, sum, sum; \ 32 addxcc t1, sum, sum; 33 34#define CSUM_LASTCHUNK(buf, offset, sum, t0, t1, t2, t3) \ 35 ldd [buf - offset - 0x08], t0; \ 36 ldd [buf - offset - 0x00], t2; \ 37 addxcc t0, sum, sum; \ 38 addxcc t1, sum, sum; \ 39 addxcc t2, sum, sum; \ 40 addxcc t3, sum, sum; 41 42 /* Do end cruft out of band to get better cache patterns. */ 43csum_partial_end_cruft: 44 be 1f ! caller asks %o1 & 0x8 45 andcc %o1, 4, %g0 ! nope, check for word remaining 46 ldd [%o0], %g2 ! load two 47 addcc %g2, %o2, %o2 ! add first word to sum 48 addxcc %g3, %o2, %o2 ! add second word as well 49 add %o0, 8, %o0 ! advance buf ptr 50 addx %g0, %o2, %o2 ! add in final carry 51 andcc %o1, 4, %g0 ! check again for word remaining 521: be 1f ! nope, skip this code 53 andcc %o1, 3, %o1 ! check for trailing bytes 54 ld [%o0], %g2 ! load it 55 addcc %g2, %o2, %o2 ! add to sum 56 add %o0, 4, %o0 ! advance buf ptr 57 addx %g0, %o2, %o2 ! add in final carry 58 andcc %o1, 3, %g0 ! check again for trailing bytes 591: be 1f ! no trailing bytes, return 60 addcc %o1, -1, %g0 ! only one byte remains? 61 bne 2f ! at least two bytes more 62 subcc %o1, 2, %o1 ! only two bytes more? 63 b 4f ! only one byte remains 64 or %g0, %g0, %o4 ! clear fake hword value 652: lduh [%o0], %o4 ! get hword 66 be 6f ! jmp if only hword remains 67 add %o0, 2, %o0 ! advance buf ptr either way 68 sll %o4, 16, %o4 ! create upper hword 694: ldub [%o0], %o5 ! get final byte 70 sll %o5, 8, %o5 ! put into place 71 or %o5, %o4, %o4 ! coalese with hword (if any) 726: addcc %o4, %o2, %o2 ! add to sum 731: retl ! get outta here 74 addx %g0, %o2, %o0 ! add final carry into retval 75 76 /* Also do alignment out of band to get better cache patterns. */ 77csum_partial_fix_alignment: 78 cmp %o1, 6 79 bl cpte - 0x4 80 andcc %o0, 0x2, %g0 81 be 1f 82 andcc %o0, 0x4, %g0 83 lduh [%o0 + 0x00], %g2 84 sub %o1, 2, %o1 85 add %o0, 2, %o0 86 sll %g2, 16, %g2 87 addcc %g2, %o2, %o2 88 srl %o2, 16, %g3 89 addx %g0, %g3, %g2 90 sll %o2, 16, %o2 91 sll %g2, 16, %g3 92 srl %o2, 16, %o2 93 andcc %o0, 0x4, %g0 94 or %g3, %o2, %o2 951: be cpa 96 andcc %o1, 0xffffff80, %o3 97 ld [%o0 + 0x00], %g2 98 sub %o1, 4, %o1 99 addcc %g2, %o2, %o2 100 add %o0, 4, %o0 101 addx %g0, %o2, %o2 102 b cpa 103 andcc %o1, 0xffffff80, %o3 104 105 /* The common case is to get called with a nicely aligned 106 * buffer of size 0x20. Follow the code path for that case. 107 */ 108 .globl csum_partial 109 EXPORT_SYMBOL(csum_partial) 110csum_partial: /* %o0=buf, %o1=len, %o2=sum */ 111 andcc %o0, 0x7, %g0 ! alignment problems? 112 bne csum_partial_fix_alignment ! yep, handle it 113 sethi %hi(cpte - 8), %g7 ! prepare table jmp ptr 114 andcc %o1, 0xffffff80, %o3 ! num loop iterations 115cpa: be 3f ! none to do 116 andcc %o1, 0x70, %g1 ! clears carry flag too 1175: CSUM_BIGCHUNK(%o0, 0x00, %o2, %o4, %o5, %g2, %g3, %g4, %g5) 118 CSUM_BIGCHUNK(%o0, 0x20, %o2, %o4, %o5, %g2, %g3, %g4, %g5) 119 CSUM_BIGCHUNK(%o0, 0x40, %o2, %o4, %o5, %g2, %g3, %g4, %g5) 120 CSUM_BIGCHUNK(%o0, 0x60, %o2, %o4, %o5, %g2, %g3, %g4, %g5) 121 addx %g0, %o2, %o2 ! sink in final carry 122 subcc %o3, 128, %o3 ! detract from loop iters 123 bne 5b ! more to do 124 add %o0, 128, %o0 ! advance buf ptr 125 andcc %o1, 0x70, %g1 ! clears carry flag too 1263: be cpte ! nope 127 andcc %o1, 0xf, %g0 ! anything left at all? 128 srl %g1, 1, %o4 ! compute offset 129 sub %g7, %g1, %g7 ! adjust jmp ptr 130 sub %g7, %o4, %g7 ! final jmp ptr adjust 131 jmp %g7 + %lo(cpte - 8) ! enter the table 132 add %o0, %g1, %o0 ! advance buf ptr 133cptbl: CSUM_LASTCHUNK(%o0, 0x68, %o2, %g2, %g3, %g4, %g5) 134 CSUM_LASTCHUNK(%o0, 0x58, %o2, %g2, %g3, %g4, %g5) 135 CSUM_LASTCHUNK(%o0, 0x48, %o2, %g2, %g3, %g4, %g5) 136 CSUM_LASTCHUNK(%o0, 0x38, %o2, %g2, %g3, %g4, %g5) 137 CSUM_LASTCHUNK(%o0, 0x28, %o2, %g2, %g3, %g4, %g5) 138 CSUM_LASTCHUNK(%o0, 0x18, %o2, %g2, %g3, %g4, %g5) 139 CSUM_LASTCHUNK(%o0, 0x08, %o2, %g2, %g3, %g4, %g5) 140 addx %g0, %o2, %o2 ! fetch final carry 141 andcc %o1, 0xf, %g0 ! anything left at all? 142cpte: bne csum_partial_end_cruft ! yep, handle it 143 andcc %o1, 8, %g0 ! check how much 144cpout: retl ! get outta here 145 mov %o2, %o0 ! return computed csum 146 147/* Work around cpp -rob */ 148#define ALLOC #alloc 149#define EXECINSTR #execinstr 150#define EX(x,y) \ 15198: x,y; \ 152 .section __ex_table,ALLOC; \ 153 .align 4; \ 154 .word 98b, cc_fault; \ 155 .text; \ 156 .align 4 157 158 /* This aligned version executes typically in 8.5 superscalar cycles, this 159 * is the best I can do. I say 8.5 because the final add will pair with 160 * the next ldd in the main unrolled loop. Thus the pipe is always full. 161 * If you change these macros (including order of instructions), 162 * please check the fixup code below as well. 163 */ 164#define CSUMCOPY_BIGCHUNK_ALIGNED(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \ 165 EX(ldd [src + off + 0x00], t0); \ 166 EX(ldd [src + off + 0x08], t2); \ 167 addxcc t0, sum, sum; \ 168 EX(ldd [src + off + 0x10], t4); \ 169 addxcc t1, sum, sum; \ 170 EX(ldd [src + off + 0x18], t6); \ 171 addxcc t2, sum, sum; \ 172 EX(std t0, [dst + off + 0x00]); \ 173 addxcc t3, sum, sum; \ 174 EX(std t2, [dst + off + 0x08]); \ 175 addxcc t4, sum, sum; \ 176 EX(std t4, [dst + off + 0x10]); \ 177 addxcc t5, sum, sum; \ 178 EX(std t6, [dst + off + 0x18]); \ 179 addxcc t6, sum, sum; \ 180 addxcc t7, sum, sum; 181 182 /* 12 superscalar cycles seems to be the limit for this case, 183 * because of this we thus do all the ldd's together to get 184 * Viking MXCC into streaming mode. Ho hum... 185 */ 186#define CSUMCOPY_BIGCHUNK(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \ 187 EX(ldd [src + off + 0x00], t0); \ 188 EX(ldd [src + off + 0x08], t2); \ 189 EX(ldd [src + off + 0x10], t4); \ 190 EX(ldd [src + off + 0x18], t6); \ 191 EX(st t0, [dst + off + 0x00]); \ 192 addxcc t0, sum, sum; \ 193 EX(st t1, [dst + off + 0x04]); \ 194 addxcc t1, sum, sum; \ 195 EX(st t2, [dst + off + 0x08]); \ 196 addxcc t2, sum, sum; \ 197 EX(st t3, [dst + off + 0x0c]); \ 198 addxcc t3, sum, sum; \ 199 EX(st t4, [dst + off + 0x10]); \ 200 addxcc t4, sum, sum; \ 201 EX(st t5, [dst + off + 0x14]); \ 202 addxcc t5, sum, sum; \ 203 EX(st t6, [dst + off + 0x18]); \ 204 addxcc t6, sum, sum; \ 205 EX(st t7, [dst + off + 0x1c]); \ 206 addxcc t7, sum, sum; 207 208 /* Yuck, 6 superscalar cycles... */ 209#define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3) \ 210 EX(ldd [src - off - 0x08], t0); \ 211 EX(ldd [src - off - 0x00], t2); \ 212 addxcc t0, sum, sum; \ 213 EX(st t0, [dst - off - 0x08]); \ 214 addxcc t1, sum, sum; \ 215 EX(st t1, [dst - off - 0x04]); \ 216 addxcc t2, sum, sum; \ 217 EX(st t2, [dst - off - 0x00]); \ 218 addxcc t3, sum, sum; \ 219 EX(st t3, [dst - off + 0x04]); 220 221 /* Handle the end cruft code out of band for better cache patterns. */ 222cc_end_cruft: 223 be 1f 224 andcc %o3, 4, %g0 225 EX(ldd [%o0 + 0x00], %g2) 226 add %o1, 8, %o1 227 addcc %g2, %g7, %g7 228 add %o0, 8, %o0 229 addxcc %g3, %g7, %g7 230 EX(st %g2, [%o1 - 0x08]) 231 addx %g0, %g7, %g7 232 andcc %o3, 4, %g0 233 EX(st %g3, [%o1 - 0x04]) 2341: be 1f 235 andcc %o3, 3, %o3 236 EX(ld [%o0 + 0x00], %g2) 237 add %o1, 4, %o1 238 addcc %g2, %g7, %g7 239 EX(st %g2, [%o1 - 0x04]) 240 addx %g0, %g7, %g7 241 andcc %o3, 3, %g0 242 add %o0, 4, %o0 2431: be 1f 244 addcc %o3, -1, %g0 245 bne 2f 246 subcc %o3, 2, %o3 247 b 4f 248 or %g0, %g0, %o4 2492: EX(lduh [%o0 + 0x00], %o4) 250 add %o0, 2, %o0 251 EX(sth %o4, [%o1 + 0x00]) 252 be 6f 253 add %o1, 2, %o1 254 sll %o4, 16, %o4 2554: EX(ldub [%o0 + 0x00], %o5) 256 EX(stb %o5, [%o1 + 0x00]) 257 sll %o5, 8, %o5 258 or %o5, %o4, %o4 2596: addcc %o4, %g7, %g7 2601: retl 261 addx %g0, %g7, %o0 262 263 /* Also, handle the alignment code out of band. */ 264cc_dword_align: 265 cmp %g1, 16 266 bge 1f 267 srl %g1, 1, %o3 2682: cmp %o3, 0 269 be,a ccte 270 andcc %g1, 0xf, %o3 271 andcc %o3, %o0, %g0 ! Check %o0 only (%o1 has the same last 2 bits) 272 be,a 2b 273 srl %o3, 1, %o3 2741: andcc %o0, 0x1, %g0 275 bne ccslow 276 andcc %o0, 0x2, %g0 277 be 1f 278 andcc %o0, 0x4, %g0 279 EX(lduh [%o0 + 0x00], %g4) 280 sub %g1, 2, %g1 281 EX(sth %g4, [%o1 + 0x00]) 282 add %o0, 2, %o0 283 sll %g4, 16, %g4 284 addcc %g4, %g7, %g7 285 add %o1, 2, %o1 286 srl %g7, 16, %g3 287 addx %g0, %g3, %g4 288 sll %g7, 16, %g7 289 sll %g4, 16, %g3 290 srl %g7, 16, %g7 291 andcc %o0, 0x4, %g0 292 or %g3, %g7, %g7 2931: be 3f 294 andcc %g1, 0xffffff80, %g0 295 EX(ld [%o0 + 0x00], %g4) 296 sub %g1, 4, %g1 297 EX(st %g4, [%o1 + 0x00]) 298 add %o0, 4, %o0 299 addcc %g4, %g7, %g7 300 add %o1, 4, %o1 301 addx %g0, %g7, %g7 302 b 3f 303 andcc %g1, 0xffffff80, %g0 304 305 /* Sun, you just can't beat me, you just can't. Stop trying, 306 * give up. I'm serious, I am going to kick the living shit 307 * out of you, game over, lights out. 308 */ 309 .align 8 310 .globl __csum_partial_copy_sparc_generic 311 EXPORT_SYMBOL(__csum_partial_copy_sparc_generic) 312__csum_partial_copy_sparc_generic: 313 /* %o0=src, %o1=dest, %g1=len, %g7=sum */ 314 xor %o0, %o1, %o4 ! get changing bits 315 andcc %o4, 3, %g0 ! check for mismatched alignment 316 bne ccslow ! better this than unaligned/fixups 317 andcc %o0, 7, %g0 ! need to align things? 318 bne cc_dword_align ! yes, we check for short lengths there 319 andcc %g1, 0xffffff80, %g0 ! can we use unrolled loop? 3203: be 3f ! nope, less than one loop remains 321 andcc %o1, 4, %g0 ! dest aligned on 4 or 8 byte boundary? 322 be ccdbl + 4 ! 8 byte aligned, kick ass 3235: CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 324 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 325 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 326 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 327 sub %g1, 128, %g1 ! detract from length 328 addx %g0, %g7, %g7 ! add in last carry bit 329 andcc %g1, 0xffffff80, %g0 ! more to csum? 330 add %o0, 128, %o0 ! advance src ptr 331 bne 5b ! we did not go negative, continue looping 332 add %o1, 128, %o1 ! advance dest ptr 3333: andcc %g1, 0x70, %o2 ! can use table? 334ccmerge:be ccte ! nope, go and check for end cruft 335 andcc %g1, 0xf, %o3 ! get low bits of length (clears carry btw) 336 srl %o2, 1, %o4 ! begin negative offset computation 337 sethi %hi(12f), %o5 ! set up table ptr end 338 add %o0, %o2, %o0 ! advance src ptr 339 sub %o5, %o4, %o5 ! continue table calculation 340 sll %o2, 1, %g2 ! constant multiplies are fun... 341 sub %o5, %g2, %o5 ! some more adjustments 342 jmp %o5 + %lo(12f) ! jump into it, duff style, wheee... 343 add %o1, %o2, %o1 ! advance dest ptr (carry is clear btw) 344cctbl: CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x68,%g2,%g3,%g4,%g5) 345 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x58,%g2,%g3,%g4,%g5) 346 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x48,%g2,%g3,%g4,%g5) 347 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x38,%g2,%g3,%g4,%g5) 348 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x28,%g2,%g3,%g4,%g5) 349 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x18,%g2,%g3,%g4,%g5) 350 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x08,%g2,%g3,%g4,%g5) 35112: addx %g0, %g7, %g7 352 andcc %o3, 0xf, %g0 ! check for low bits set 353ccte: bne cc_end_cruft ! something left, handle it out of band 354 andcc %o3, 8, %g0 ! begin checks for that code 355 retl ! return 356 mov %g7, %o0 ! give em the computed checksum 357ccdbl: CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 358 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 359 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 360 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 361 sub %g1, 128, %g1 ! detract from length 362 addx %g0, %g7, %g7 ! add in last carry bit 363 andcc %g1, 0xffffff80, %g0 ! more to csum? 364 add %o0, 128, %o0 ! advance src ptr 365 bne ccdbl ! we did not go negative, continue looping 366 add %o1, 128, %o1 ! advance dest ptr 367 b ccmerge ! finish it off, above 368 andcc %g1, 0x70, %o2 ! can use table? (clears carry btw) 369 370ccslow: cmp %g1, 0 371 mov 0, %g5 372 bleu 4f 373 andcc %o0, 1, %o5 374 be,a 1f 375 srl %g1, 1, %g4 376 sub %g1, 1, %g1 377 EX(ldub [%o0], %g5) 378 add %o0, 1, %o0 379 EX(stb %g5, [%o1]) 380 srl %g1, 1, %g4 381 add %o1, 1, %o1 3821: cmp %g4, 0 383 be,a 3f 384 andcc %g1, 1, %g0 385 andcc %o0, 2, %g0 386 be,a 1f 387 srl %g4, 1, %g4 388 EX(lduh [%o0], %o4) 389 sub %g1, 2, %g1 390 srl %o4, 8, %g2 391 sub %g4, 1, %g4 392 EX(stb %g2, [%o1]) 393 add %o4, %g5, %g5 394 EX(stb %o4, [%o1 + 1]) 395 add %o0, 2, %o0 396 srl %g4, 1, %g4 397 add %o1, 2, %o1 3981: cmp %g4, 0 399 be,a 2f 400 andcc %g1, 2, %g0 401 EX(ld [%o0], %o4) 4025: srl %o4, 24, %g2 403 srl %o4, 16, %g3 404 EX(stb %g2, [%o1]) 405 srl %o4, 8, %g2 406 EX(stb %g3, [%o1 + 1]) 407 add %o0, 4, %o0 408 EX(stb %g2, [%o1 + 2]) 409 addcc %o4, %g5, %g5 410 EX(stb %o4, [%o1 + 3]) 411 addx %g5, %g0, %g5 ! I am now to lazy to optimize this (question it 412 add %o1, 4, %o1 ! is worthy). Maybe some day - with the sll/srl 413 subcc %g4, 1, %g4 ! tricks 414 bne,a 5b 415 EX(ld [%o0], %o4) 416 sll %g5, 16, %g2 417 srl %g5, 16, %g5 418 srl %g2, 16, %g2 419 andcc %g1, 2, %g0 420 add %g2, %g5, %g5 4212: be,a 3f 422 andcc %g1, 1, %g0 423 EX(lduh [%o0], %o4) 424 andcc %g1, 1, %g0 425 srl %o4, 8, %g2 426 add %o0, 2, %o0 427 EX(stb %g2, [%o1]) 428 add %g5, %o4, %g5 429 EX(stb %o4, [%o1 + 1]) 430 add %o1, 2, %o1 4313: be,a 1f 432 sll %g5, 16, %o4 433 EX(ldub [%o0], %g2) 434 sll %g2, 8, %o4 435 EX(stb %g2, [%o1]) 436 add %g5, %o4, %g5 437 sll %g5, 16, %o4 4381: addcc %o4, %g5, %g5 439 srl %g5, 16, %o4 440 addx %g0, %o4, %g5 441 orcc %o5, %g0, %g0 442 be 4f 443 srl %g5, 8, %o4 444 and %g5, 0xff, %g2 445 and %o4, 0xff, %o4 446 sll %g2, 8, %g2 447 or %g2, %o4, %g5 4484: addcc %g7, %g5, %g7 449 retl 450 addx %g0, %g7, %o0 451 452/* We do these strange calculations for the csum_*_from_user case only, ie. 453 * we only bother with faults on loads... */ 454 455cc_fault: 456 ret 457 clr %o0 458