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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 | /* * csum_partial_copy - do IP checksumming and copy * * (C) Copyright 1996 Linus Torvalds * accellerated versions (and 21264 assembly versions ) contributed by * Rick Gorton <rick.gorton@alpha-processor.com> * * Don't look at this too closely - you'll go mad. The things * we do for performance.. */ #include <linux/types.h> #include <linux/string.h> #include <asm/uaccess.h> #define ldq_u(x,y) \ __asm__ __volatile__("ldq_u %0,%1":"=r" (x):"m" (*(const unsigned long *)(y))) #define stq_u(x,y) \ __asm__ __volatile__("stq_u %1,%0":"=m" (*(unsigned long *)(y)):"r" (x)) #define extql(x,y,z) \ __asm__ __volatile__("extql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) #define extqh(x,y,z) \ __asm__ __volatile__("extqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) #define mskql(x,y,z) \ __asm__ __volatile__("mskql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) #define mskqh(x,y,z) \ __asm__ __volatile__("mskqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) #define insql(x,y,z) \ __asm__ __volatile__("insql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) #define insqh(x,y,z) \ __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) #define __get_user_u(x,ptr) \ ({ \ long __guu_err; \ __asm__ __volatile__( \ "1: ldq_u %0,%2\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .gprel32 1b\n" \ " lda %0,2b-1b(%1)\n" \ ".previous" \ : "=r"(x), "=r"(__guu_err) \ : "m"(__m(ptr)), "1"(0)); \ __guu_err; \ }) #define __put_user_u(x,ptr) \ ({ \ long __puu_err; \ __asm__ __volatile__( \ "1: stq_u %2,%1\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .gprel32 1b" \ " lda $31,2b-1b(%0)\n" \ ".previous" \ : "=r"(__puu_err) \ : "m"(__m(addr)), "rJ"(x), "0"(0)); \ __puu_err; \ }) static inline unsigned short from64to16(unsigned long x) { /* Using extract instructions is a bit more efficient than the original shift/bitmask version. */ union { unsigned long ul; unsigned int ui[2]; unsigned short us[4]; } in_v, tmp_v, out_v; in_v.ul = x; tmp_v.ul = (unsigned long) in_v.ui[0] + (unsigned long) in_v.ui[1]; /* Since the bits of tmp_v.sh[3] are going to always be zero, we don't have to bother to add that in. */ out_v.ul = (unsigned long) tmp_v.us[0] + (unsigned long) tmp_v.us[1] + (unsigned long) tmp_v.us[2]; /* Similarly, out_v.us[2] is always zero for the final add. */ return out_v.us[0] + out_v.us[1]; } /* * Ok. This isn't fun, but this is the EASY case. */ static inline unsigned long csum_partial_cfu_aligned(const unsigned long *src, unsigned long *dst, long len, unsigned long checksum, int *errp) { unsigned long carry = 0; int err = 0; while (len >= 0) { unsigned long word; err |= __get_user(word, src); checksum += carry; src++; checksum += word; len -= 8; carry = checksum < word; *dst = word; dst++; } len += 8; checksum += carry; if (len) { unsigned long word, tmp; err |= __get_user(word, src); tmp = *dst; mskql(word, len, word); checksum += word; mskqh(tmp, len, tmp); carry = checksum < word; *dst = word | tmp; checksum += carry; } if (err) *errp = err; return checksum; } /* * This is even less fun, but this is still reasonably * easy. */ static inline unsigned long csum_partial_cfu_dest_aligned(const unsigned long *src, unsigned long *dst, unsigned long soff, long len, unsigned long checksum, int *errp) { unsigned long first; unsigned long word, carry; unsigned long lastsrc = 7+len+(unsigned long)src; int err = 0; err |= __get_user_u(first,src); carry = 0; while (len >= 0) { unsigned long second; err |= __get_user_u(second, src+1); extql(first, soff, word); len -= 8; src++; extqh(second, soff, first); checksum += carry; word |= first; first = second; checksum += word; *dst = word; dst++; carry = checksum < word; } len += 8; checksum += carry; if (len) { unsigned long tmp; unsigned long second; err |= __get_user_u(second, lastsrc); tmp = *dst; extql(first, soff, word); extqh(second, soff, first); word |= first; mskql(word, len, word); checksum += word; mskqh(tmp, len, tmp); carry = checksum < word; *dst = word | tmp; checksum += carry; } if (err) *errp = err; return checksum; } /* * This is slightly less fun than the above.. */ static inline unsigned long csum_partial_cfu_src_aligned(const unsigned long *src, unsigned long *dst, unsigned long doff, long len, unsigned long checksum, unsigned long partial_dest, int *errp) { unsigned long carry = 0; unsigned long word; unsigned long second_dest; int err = 0; mskql(partial_dest, doff, partial_dest); while (len >= 0) { err |= __get_user(word, src); len -= 8; insql(word, doff, second_dest); checksum += carry; stq_u(partial_dest | second_dest, dst); src++; checksum += word; insqh(word, doff, partial_dest); carry = checksum < word; dst++; } len += 8; if (len) { checksum += carry; err |= __get_user(word, src); mskql(word, len, word); len -= 8; checksum += word; insql(word, doff, second_dest); len += doff; carry = checksum < word; partial_dest |= second_dest; if (len >= 0) { stq_u(partial_dest, dst); if (!len) goto out; dst++; insqh(word, doff, partial_dest); } doff = len; } ldq_u(second_dest, dst); mskqh(second_dest, doff, second_dest); stq_u(partial_dest | second_dest, dst); out: checksum += carry; if (err) *errp = err; return checksum; } /* * This is so totally un-fun that it's frightening. Don't * look at this too closely, you'll go blind. */ static inline unsigned long csum_partial_cfu_unaligned(const unsigned long * src, unsigned long * dst, unsigned long soff, unsigned long doff, long len, unsigned long checksum, unsigned long partial_dest, int *errp) { unsigned long carry = 0; unsigned long first; unsigned long lastsrc; int err = 0; err |= __get_user_u(first, src); lastsrc = 7+len+(unsigned long)src; mskql(partial_dest, doff, partial_dest); while (len >= 0) { unsigned long second, word; unsigned long second_dest; err |= __get_user_u(second, src+1); extql(first, soff, word); checksum += carry; len -= 8; extqh(second, soff, first); src++; word |= first; first = second; insql(word, doff, second_dest); checksum += word; stq_u(partial_dest | second_dest, dst); carry = checksum < word; insqh(word, doff, partial_dest); dst++; } len += doff; checksum += carry; if (len >= 0) { unsigned long second, word; unsigned long second_dest; err |= __get_user_u(second, lastsrc); extql(first, soff, word); extqh(second, soff, first); word |= first; first = second; mskql(word, len-doff, word); checksum += word; insql(word, doff, second_dest); carry = checksum < word; stq_u(partial_dest | second_dest, dst); if (len) { ldq_u(second_dest, dst+1); insqh(word, doff, partial_dest); mskqh(second_dest, len, second_dest); stq_u(partial_dest | second_dest, dst+1); } checksum += carry; } else { unsigned long second, word; unsigned long second_dest; err |= __get_user_u(second, lastsrc); extql(first, soff, word); extqh(second, soff, first); word |= first; ldq_u(second_dest, dst); mskql(word, len-doff, word); checksum += word; mskqh(second_dest, len, second_dest); carry = checksum < word; insql(word, doff, word); stq_u(partial_dest | word | second_dest, dst); checksum += carry; } if (err) *errp = err; return checksum; } static unsigned int do_csum_partial_copy_from_user(const char *src, char *dst, int len, unsigned int sum, int *errp) { unsigned long checksum = (unsigned) sum; unsigned long soff = 7 & (unsigned long) src; unsigned long doff = 7 & (unsigned long) dst; if (len) { if (!doff) { if (!soff) checksum = csum_partial_cfu_aligned( (const unsigned long *) src, (unsigned long *) dst, len-8, checksum, errp); else checksum = csum_partial_cfu_dest_aligned( (const unsigned long *) src, (unsigned long *) dst, soff, len-8, checksum, errp); } else { unsigned long partial_dest; ldq_u(partial_dest, dst); if (!soff) checksum = csum_partial_cfu_src_aligned( (const unsigned long *) src, (unsigned long *) dst, doff, len-8, checksum, partial_dest, errp); else checksum = csum_partial_cfu_unaligned( (const unsigned long *) src, (unsigned long *) dst, soff, doff, len-8, checksum, partial_dest, errp); } checksum = from64to16 (checksum); } return checksum; } unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, unsigned int sum, int *errp) { if (!access_ok(src, len, VERIFY_READ)) { *errp = -EFAULT; memset(dst, 0, len); return sum; } return do_csum_partial_copy_from_user(src, dst, len, sum, errp); } unsigned int csum_partial_copy_nocheck(const char *src, char *dst, int len, unsigned int sum) { return do_csum_partial_copy_from_user(src, dst, len, sum, NULL); } |