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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 | /* SPDX-License-Identifier: GPL-2.0-or-later */ /* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * IP/TCP/UDP checksumming routines * * Authors: Jorge Cwik, <jorge@laser.satlink.net> * Arnt Gulbrandsen, <agulbra@nvg.unit.no> * Tom May, <ftom@netcom.com> * Pentium Pro/II routines: * Alexander Kjeldaas <astor@guardian.no> * Finn Arne Gangstad <finnag@guardian.no> * Lots of code moved from tcp.c and ip.c; see those files * for more names. * * Changes: Ingo Molnar, converted csum_partial_copy() to 2.1 exception * handling. * Andi Kleen, add zeroing on error * converted to pure assembler */ #include <linux/export.h> #include <linux/linkage.h> #include <asm/errno.h> #include <asm/asm.h> #include <asm/nospec-branch.h> /* * computes a partial checksum, e.g. for TCP/UDP fragments */ /* unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) */ .text #ifndef CONFIG_X86_USE_PPRO_CHECKSUM /* * Experiments with Ethernet and SLIP connections show that buff * is aligned on either a 2-byte or 4-byte boundary. We get at * least a twofold speedup on 486 and Pentium if it is 4-byte aligned. * Fortunately, it is easy to convert 2-byte alignment to 4-byte * alignment for the unrolled loop. */ SYM_FUNC_START(csum_partial) pushl %esi pushl %ebx movl 20(%esp),%eax # Function arg: unsigned int sum movl 16(%esp),%ecx # Function arg: int len movl 12(%esp),%esi # Function arg: unsigned char *buff testl $3, %esi # Check alignment. jz 2f # Jump if alignment is ok. testl $1, %esi # Check alignment. jz 10f # Jump if alignment is boundary of 2 bytes. # buf is odd dec %ecx jl 8f movzbl (%esi), %ebx adcl %ebx, %eax roll $8, %eax inc %esi testl $2, %esi jz 2f 10: subl $2, %ecx # Alignment uses up two bytes. jae 1f # Jump if we had at least two bytes. addl $2, %ecx # ecx was < 2. Deal with it. jmp 4f 1: movw (%esi), %bx addl $2, %esi addw %bx, %ax adcl $0, %eax 2: movl %ecx, %edx shrl $5, %ecx jz 2f testl %esi, %esi 1: movl (%esi), %ebx adcl %ebx, %eax movl 4(%esi), %ebx adcl %ebx, %eax movl 8(%esi), %ebx adcl %ebx, %eax movl 12(%esi), %ebx adcl %ebx, %eax movl 16(%esi), %ebx adcl %ebx, %eax movl 20(%esi), %ebx adcl %ebx, %eax movl 24(%esi), %ebx adcl %ebx, %eax movl 28(%esi), %ebx adcl %ebx, %eax lea 32(%esi), %esi dec %ecx jne 1b adcl $0, %eax 2: movl %edx, %ecx andl $0x1c, %edx je 4f shrl $2, %edx # This clears CF 3: adcl (%esi), %eax lea 4(%esi), %esi dec %edx jne 3b adcl $0, %eax 4: andl $3, %ecx jz 7f cmpl $2, %ecx jb 5f movw (%esi),%cx leal 2(%esi),%esi je 6f shll $16,%ecx 5: movb (%esi),%cl 6: addl %ecx,%eax adcl $0, %eax 7: testb $1, 12(%esp) jz 8f roll $8, %eax 8: popl %ebx popl %esi RET SYM_FUNC_END(csum_partial) #else /* Version for PentiumII/PPro */ SYM_FUNC_START(csum_partial) pushl %esi pushl %ebx movl 20(%esp),%eax # Function arg: unsigned int sum movl 16(%esp),%ecx # Function arg: int len movl 12(%esp),%esi # Function arg: const unsigned char *buf testl $3, %esi jnz 25f 10: movl %ecx, %edx movl %ecx, %ebx andl $0x7c, %ebx shrl $7, %ecx addl %ebx,%esi shrl $2, %ebx negl %ebx lea 45f(%ebx,%ebx,2), %ebx testl %esi, %esi JMP_NOSPEC ebx # Handle 2-byte-aligned regions 20: addw (%esi), %ax lea 2(%esi), %esi adcl $0, %eax jmp 10b 25: testl $1, %esi jz 30f # buf is odd dec %ecx jl 90f movzbl (%esi), %ebx addl %ebx, %eax adcl $0, %eax roll $8, %eax inc %esi testl $2, %esi jz 10b 30: subl $2, %ecx ja 20b je 32f addl $2, %ecx jz 80f movzbl (%esi),%ebx # csumming 1 byte, 2-aligned addl %ebx, %eax adcl $0, %eax jmp 80f 32: addw (%esi), %ax # csumming 2 bytes, 2-aligned adcl $0, %eax jmp 80f 40: addl -128(%esi), %eax adcl -124(%esi), %eax adcl -120(%esi), %eax adcl -116(%esi), %eax adcl -112(%esi), %eax adcl -108(%esi), %eax adcl -104(%esi), %eax adcl -100(%esi), %eax adcl -96(%esi), %eax adcl -92(%esi), %eax adcl -88(%esi), %eax adcl -84(%esi), %eax adcl -80(%esi), %eax adcl -76(%esi), %eax adcl -72(%esi), %eax adcl -68(%esi), %eax adcl -64(%esi), %eax adcl -60(%esi), %eax adcl -56(%esi), %eax adcl -52(%esi), %eax adcl -48(%esi), %eax adcl -44(%esi), %eax adcl -40(%esi), %eax adcl -36(%esi), %eax adcl -32(%esi), %eax adcl -28(%esi), %eax adcl -24(%esi), %eax adcl -20(%esi), %eax adcl -16(%esi), %eax adcl -12(%esi), %eax adcl -8(%esi), %eax adcl -4(%esi), %eax 45: lea 128(%esi), %esi adcl $0, %eax dec %ecx jge 40b movl %edx, %ecx 50: andl $3, %ecx jz 80f # Handle the last 1-3 bytes without jumping notl %ecx # 1->2, 2->1, 3->0, higher bits are masked movl $0xffffff,%ebx # by the shll and shrl instructions shll $3,%ecx shrl %cl,%ebx andl -128(%esi),%ebx # esi is 4-aligned so should be ok addl %ebx,%eax adcl $0,%eax 80: testb $1, 12(%esp) jz 90f roll $8, %eax 90: popl %ebx popl %esi RET SYM_FUNC_END(csum_partial) #endif EXPORT_SYMBOL(csum_partial) /* unsigned int csum_partial_copy_generic (const char *src, char *dst, int len) */ /* * Copy from ds while checksumming, otherwise like csum_partial */ #define EXC(y...) \ 9999: y; \ _ASM_EXTABLE_TYPE(9999b, 7f, EX_TYPE_UACCESS | EX_FLAG_CLEAR_AX) #ifndef CONFIG_X86_USE_PPRO_CHECKSUM #define ARGBASE 16 #define FP 12 SYM_FUNC_START(csum_partial_copy_generic) subl $4,%esp pushl %edi pushl %esi pushl %ebx movl ARGBASE+12(%esp),%ecx # len movl ARGBASE+4(%esp),%esi # src movl ARGBASE+8(%esp),%edi # dst movl $-1, %eax # sum testl $2, %edi # Check alignment. jz 2f # Jump if alignment is ok. subl $2, %ecx # Alignment uses up two bytes. jae 1f # Jump if we had at least two bytes. addl $2, %ecx # ecx was < 2. Deal with it. jmp 4f EXC(1: movw (%esi), %bx ) addl $2, %esi EXC( movw %bx, (%edi) ) addl $2, %edi addw %bx, %ax adcl $0, %eax 2: movl %ecx, FP(%esp) shrl $5, %ecx jz 2f testl %esi, %esi # what's wrong with clc? EXC(1: movl (%esi), %ebx ) EXC( movl 4(%esi), %edx ) adcl %ebx, %eax EXC( movl %ebx, (%edi) ) adcl %edx, %eax EXC( movl %edx, 4(%edi) ) EXC( movl 8(%esi), %ebx ) EXC( movl 12(%esi), %edx ) adcl %ebx, %eax EXC( movl %ebx, 8(%edi) ) adcl %edx, %eax EXC( movl %edx, 12(%edi) ) EXC( movl 16(%esi), %ebx ) EXC( movl 20(%esi), %edx ) adcl %ebx, %eax EXC( movl %ebx, 16(%edi) ) adcl %edx, %eax EXC( movl %edx, 20(%edi) ) EXC( movl 24(%esi), %ebx ) EXC( movl 28(%esi), %edx ) adcl %ebx, %eax EXC( movl %ebx, 24(%edi) ) adcl %edx, %eax EXC( movl %edx, 28(%edi) ) lea 32(%esi), %esi lea 32(%edi), %edi dec %ecx jne 1b adcl $0, %eax 2: movl FP(%esp), %edx movl %edx, %ecx andl $0x1c, %edx je 4f shrl $2, %edx # This clears CF EXC(3: movl (%esi), %ebx ) adcl %ebx, %eax EXC( movl %ebx, (%edi) ) lea 4(%esi), %esi lea 4(%edi), %edi dec %edx jne 3b adcl $0, %eax 4: andl $3, %ecx jz 7f cmpl $2, %ecx jb 5f EXC( movw (%esi), %cx ) leal 2(%esi), %esi EXC( movw %cx, (%edi) ) leal 2(%edi), %edi je 6f shll $16,%ecx EXC(5: movb (%esi), %cl ) EXC( movb %cl, (%edi) ) 6: addl %ecx, %eax adcl $0, %eax 7: popl %ebx popl %esi popl %edi popl %ecx # equivalent to addl $4,%esp RET SYM_FUNC_END(csum_partial_copy_generic) #else /* Version for PentiumII/PPro */ #define ROUND1(x) \ EXC(movl x(%esi), %ebx ) ; \ addl %ebx, %eax ; \ EXC(movl %ebx, x(%edi) ) ; #define ROUND(x) \ EXC(movl x(%esi), %ebx ) ; \ adcl %ebx, %eax ; \ EXC(movl %ebx, x(%edi) ) ; #define ARGBASE 12 SYM_FUNC_START(csum_partial_copy_generic) pushl %ebx pushl %edi pushl %esi movl ARGBASE+4(%esp),%esi #src movl ARGBASE+8(%esp),%edi #dst movl ARGBASE+12(%esp),%ecx #len movl $-1, %eax #sum # movl %ecx, %edx movl %ecx, %ebx movl %esi, %edx shrl $6, %ecx andl $0x3c, %ebx negl %ebx subl %ebx, %esi subl %ebx, %edi lea -1(%esi),%edx andl $-32,%edx lea 3f(%ebx,%ebx), %ebx testl %esi, %esi JMP_NOSPEC ebx 1: addl $64,%esi addl $64,%edi EXC(movb -32(%edx),%bl) ; EXC(movb (%edx),%bl) ROUND1(-64) ROUND(-60) ROUND(-56) ROUND(-52) ROUND (-48) ROUND(-44) ROUND(-40) ROUND(-36) ROUND (-32) ROUND(-28) ROUND(-24) ROUND(-20) ROUND (-16) ROUND(-12) ROUND(-8) ROUND(-4) 3: adcl $0,%eax addl $64, %edx dec %ecx jge 1b 4: movl ARGBASE+12(%esp),%edx #len andl $3, %edx jz 7f cmpl $2, %edx jb 5f EXC( movw (%esi), %dx ) leal 2(%esi), %esi EXC( movw %dx, (%edi) ) leal 2(%edi), %edi je 6f shll $16,%edx 5: EXC( movb (%esi), %dl ) EXC( movb %dl, (%edi) ) 6: addl %edx, %eax adcl $0, %eax 7: popl %esi popl %edi popl %ebx RET SYM_FUNC_END(csum_partial_copy_generic) #undef ROUND #undef ROUND1 #endif EXPORT_SYMBOL(csum_partial_copy_generic) |