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#define EXT(start,end) \ 159 .section __ex_table,ALLOC; \ 160 .align 4; \ 161 .word start, 0, end, cc_fault; \ 162 .text; \ 163 .align 4 164 165 /* This aligned version executes typically in 8.5 superscalar cycles, this 166 * is the best I can do. I say 8.5 because the final add will pair with 167 * the next ldd in the main unrolled loop. Thus the pipe is always full. 168 * If you change these macros (including order of instructions), 169 * please check the fixup code below as well. 170 */ 171#define CSUMCOPY_BIGCHUNK_ALIGNED(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \ 172 ldd [src + off + 0x00], t0; \ 173 ldd [src + off + 0x08], t2; \ 174 addxcc t0, sum, sum; \ 175 ldd [src + off + 0x10], t4; \ 176 addxcc t1, sum, sum; \ 177 ldd [src + off + 0x18], t6; \ 178 addxcc t2, sum, sum; \ 179 std t0, [dst + off + 0x00]; \ 180 addxcc t3, sum, sum; \ 181 std t2, [dst + off + 0x08]; \ 182 addxcc t4, sum, sum; \ 183 std t4, [dst + off + 0x10]; \ 184 addxcc t5, sum, sum; \ 185 std t6, [dst + off + 0x18]; \ 186 addxcc t6, sum, sum; \ 187 addxcc t7, sum, sum; 188 189 /* 12 superscalar cycles seems to be the limit for this case, 190 * because of this we thus do all the ldd's together to get 191 * Viking MXCC into streaming mode. Ho hum... 192 */ 193#define CSUMCOPY_BIGCHUNK(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \ 194 ldd [src + off + 0x00], t0; \ 195 ldd [src + off + 0x08], t2; \ 196 ldd [src + off + 0x10], t4; \ 197 ldd [src + off + 0x18], t6; \ 198 st t0, [dst + off + 0x00]; \ 199 addxcc t0, sum, sum; \ 200 st t1, [dst + off + 0x04]; \ 201 addxcc t1, sum, sum; \ 202 st t2, [dst + off + 0x08]; \ 203 addxcc t2, sum, sum; \ 204 st t3, [dst + off + 0x0c]; \ 205 addxcc t3, sum, sum; \ 206 st t4, [dst + off + 0x10]; \ 207 addxcc t4, sum, sum; \ 208 st t5, [dst + off + 0x14]; \ 209 addxcc t5, sum, sum; \ 210 st t6, [dst + off + 0x18]; \ 211 addxcc t6, sum, sum; \ 212 st t7, [dst + off + 0x1c]; \ 213 addxcc t7, sum, sum; 214 215 /* Yuck, 6 superscalar cycles... */ 216#define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3) \ 217 ldd [src - off - 0x08], t0; \ 218 ldd [src - off - 0x00], t2; \ 219 addxcc t0, sum, sum; \ 220 st t0, [dst - off - 0x08]; \ 221 addxcc t1, sum, sum; \ 222 st t1, [dst - off - 0x04]; \ 223 addxcc t2, sum, sum; \ 224 st t2, [dst - off - 0x00]; \ 225 addxcc t3, sum, sum; \ 226 st t3, [dst - off + 0x04]; 227 228 /* Handle the end cruft code out of band for better cache patterns. */ 229cc_end_cruft: 230 be 1f 231 andcc %o3, 4, %g0 232 EX(ldd [%o0 + 0x00], %g2) 233 add %o1, 8, %o1 234 addcc %g2, %g7, %g7 235 add %o0, 8, %o0 236 addxcc %g3, %g7, %g7 237 EX(st %g2, [%o1 - 0x08]) 238 addx %g0, %g7, %g7 239 andcc %o3, 4, %g0 240 EX(st %g3, [%o1 - 0x04]) 2411: be 1f 242 andcc %o3, 3, %o3 243 EX(ld [%o0 + 0x00], %g2) 244 add %o1, 4, %o1 245 addcc %g2, %g7, %g7 246 EX(st %g2, [%o1 - 0x04]) 247 addx %g0, %g7, %g7 248 andcc %o3, 3, %g0 249 add %o0, 4, %o0 2501: be 1f 251 addcc %o3, -1, %g0 252 bne 2f 253 subcc %o3, 2, %o3 254 b 4f 255 or %g0, %g0, %o4 2562: EX(lduh [%o0 + 0x00], %o4) 257 add %o0, 2, %o0 258 EX(sth %o4, [%o1 + 0x00]) 259 be 6f 260 add %o1, 2, %o1 261 sll %o4, 16, %o4 2624: EX(ldub [%o0 + 0x00], %o5) 263 EX(stb %o5, [%o1 + 0x00]) 264 sll %o5, 8, %o5 265 or %o5, %o4, %o4 2666: addcc %o4, %g7, %g7 2671: retl 268 addx %g0, %g7, %o0 269 270 /* Also, handle the alignment code out of band. */ 271cc_dword_align: 272 cmp %g1, 16 273 bge 1f 274 srl %g1, 1, %o3 2752: cmp %o3, 0 276 be,a ccte 277 andcc %g1, 0xf, %o3 278 andcc %o3, %o0, %g0 ! Check %o0 only (%o1 has the same last 2 bits) 279 be,a 2b 280 srl %o3, 1, %o3 2811: andcc %o0, 0x1, %g0 282 bne ccslow 283 andcc %o0, 0x2, %g0 284 be 1f 285 andcc %o0, 0x4, %g0 286 EX(lduh [%o0 + 0x00], %g4) 287 sub %g1, 2, %g1 288 EX(sth %g4, [%o1 + 0x00]) 289 add %o0, 2, %o0 290 sll %g4, 16, %g4 291 addcc %g4, %g7, %g7 292 add %o1, 2, %o1 293 srl %g7, 16, %g3 294 addx %g0, %g3, %g4 295 sll %g7, 16, %g7 296 sll %g4, 16, %g3 297 srl %g7, 16, %g7 298 andcc %o0, 0x4, %g0 299 or %g3, %g7, %g7 3001: be 3f 301 andcc %g1, 0xffffff80, %g0 302 EX(ld [%o0 + 0x00], %g4) 303 sub %g1, 4, %g1 304 EX(st %g4, [%o1 + 0x00]) 305 add %o0, 4, %o0 306 addcc %g4, %g7, %g7 307 add %o1, 4, %o1 308 addx %g0, %g7, %g7 309 b 3f 310 andcc %g1, 0xffffff80, %g0 311 312 /* Sun, you just can't beat me, you just can't. Stop trying, 313 * give up. I'm serious, I am going to kick the living shit 314 * out of you, game over, lights out. 315 */ 316 .align 8 317 .globl __csum_partial_copy_sparc_generic 318 EXPORT_SYMBOL(__csum_partial_copy_sparc_generic) 319__csum_partial_copy_sparc_generic: 320 /* %o0=src, %o1=dest, %g1=len, %g7=sum */ 321 xor %o0, %o1, %o4 ! get changing bits 322 andcc %o4, 3, %g0 ! check for mismatched alignment 323 bne ccslow ! better this than unaligned/fixups 324 andcc %o0, 7, %g0 ! need to align things? 325 bne cc_dword_align ! yes, we check for short lengths there 326 andcc %g1, 0xffffff80, %g0 ! can we use unrolled loop? 3273: be 3f ! nope, less than one loop remains 328 andcc %o1, 4, %g0 ! dest aligned on 4 or 8 byte boundary? 329 be ccdbl + 4 ! 8 byte aligned, kick ass 3305: CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 331 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 332 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 333 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 33410: EXT(5b, 10b) ! note for exception handling 335 sub %g1, 128, %g1 ! detract from length 336 addx %g0, %g7, %g7 ! add in last carry bit 337 andcc %g1, 0xffffff80, %g0 ! more to csum? 338 add %o0, 128, %o0 ! advance src ptr 339 bne 5b ! we did not go negative, continue looping 340 add %o1, 128, %o1 ! advance dest ptr 3413: andcc %g1, 0x70, %o2 ! can use table? 342ccmerge:be ccte ! nope, go and check for end cruft 343 andcc %g1, 0xf, %o3 ! get low bits of length (clears carry btw) 344 srl %o2, 1, %o4 ! begin negative offset computation 345 sethi %hi(12f), %o5 ! set up table ptr end 346 add %o0, %o2, %o0 ! advance src ptr 347 sub %o5, %o4, %o5 ! continue table calculation 348 sll %o2, 1, %g2 ! constant multiplies are fun... 349 sub %o5, %g2, %o5 ! some more adjustments 350 jmp %o5 + %lo(12f) ! jump into it, duff style, wheee... 351 add %o1, %o2, %o1 ! advance dest ptr (carry is clear btw) 352cctbl: CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x68,%g2,%g3,%g4,%g5) 353 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x58,%g2,%g3,%g4,%g5) 354 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x48,%g2,%g3,%g4,%g5) 355 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x38,%g2,%g3,%g4,%g5) 356 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x28,%g2,%g3,%g4,%g5) 357 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x18,%g2,%g3,%g4,%g5) 358 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x08,%g2,%g3,%g4,%g5) 35912: EXT(cctbl, 12b) ! note for exception table handling 360 addx %g0, %g7, %g7 361 andcc %o3, 0xf, %g0 ! check for low bits set 362ccte: bne cc_end_cruft ! something left, handle it out of band 363 andcc %o3, 8, %g0 ! begin checks for that code 364 retl ! return 365 mov %g7, %o0 ! give em the computed checksum 366ccdbl: CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 367 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 368 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 369 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3) 37011: EXT(ccdbl, 11b) ! note for exception table handling 371 sub %g1, 128, %g1 ! detract from length 372 addx %g0, %g7, %g7 ! add in last carry bit 373 andcc %g1, 0xffffff80, %g0 ! more to csum? 374 add %o0, 128, %o0 ! advance src ptr 375 bne ccdbl ! we did not go negative, continue looping 376 add %o1, 128, %o1 ! advance dest ptr 377 b ccmerge ! finish it off, above 378 andcc %g1, 0x70, %o2 ! can use table? (clears carry btw) 379 380ccslow: cmp %g1, 0 381 mov 0, %g5 382 bleu 4f 383 andcc %o0, 1, %o5 384 be,a 1f 385 srl %g1, 1, %g4 386 sub %g1, 1, %g1 387 EX(ldub [%o0], %g5) 388 add %o0, 1, %o0 389 EX(stb %g5, [%o1]) 390 srl %g1, 1, %g4 391 add %o1, 1, %o1 3921: cmp %g4, 0 393 be,a 3f 394 andcc %g1, 1, %g0 395 andcc %o0, 2, %g0 396 be,a 1f 397 srl %g4, 1, %g4 398 EX(lduh [%o0], %o4) 399 sub %g1, 2, %g1 400 srl %o4, 8, %g2 401 sub %g4, 1, %g4 402 EX(stb %g2, [%o1]) 403 add %o4, %g5, %g5 404 EX(stb %o4, [%o1 + 1]) 405 add %o0, 2, %o0 406 srl %g4, 1, %g4 407 add %o1, 2, %o1 4081: cmp %g4, 0 409 be,a 2f 410 andcc %g1, 2, %g0 411 EX(ld [%o0], %o4) 4125: srl %o4, 24, %g2 413 srl %o4, 16, %g3 414 EX(stb %g2, [%o1]) 415 srl %o4, 8, %g2 416 EX(stb %g3, [%o1 + 1]) 417 add %o0, 4, %o0 418 EX(stb %g2, [%o1 + 2]) 419 addcc %o4, %g5, %g5 420 EX(stb %o4, [%o1 + 3]) 421 addx %g5, %g0, %g5 ! I am now to lazy to optimize this (question it 422 add %o1, 4, %o1 ! is worthy). Maybe some day - with the sll/srl 423 subcc %g4, 1, %g4 ! tricks 424 bne,a 5b 425 EX(ld [%o0], %o4) 426 sll %g5, 16, %g2 427 srl %g5, 16, %g5 428 srl %g2, 16, %g2 429 andcc %g1, 2, %g0 430 add %g2, %g5, %g5 4312: be,a 3f 432 andcc %g1, 1, %g0 433 EX(lduh [%o0], %o4) 434 andcc %g1, 1, %g0 435 srl %o4, 8, %g2 436 add %o0, 2, %o0 437 EX(stb %g2, [%o1]) 438 add %g5, %o4, %g5 439 EX(stb %o4, [%o1 + 1]) 440 add %o1, 2, %o1 4413: be,a 1f 442 sll %g5, 16, %o4 443 EX(ldub [%o0], %g2) 444 sll %g2, 8, %o4 445 EX(stb %g2, [%o1]) 446 add %g5, %o4, %g5 447 sll %g5, 16, %o4 4481: addcc %o4, %g5, %g5 449 srl %g5, 16, %o4 450 addx %g0, %o4, %g5 451 orcc %o5, %g0, %g0 452 be 4f 453 srl %g5, 8, %o4 454 and %g5, 0xff, %g2 455 and %o4, 0xff, %o4 456 sll %g2, 8, %g2 457 or %g2, %o4, %g5 4584: addcc %g7, %g5, %g7 459 retl 460 addx %g0, %g7, %o0 461 462/* We do these strange calculations for the csum_*_from_user case only, ie. 463 * we only bother with faults on loads... */ 464 465cc_fault: 466 ret 467 clr %o0 468