Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * csum_partial_copy - do IP checksumming and copy |
| 3 | * |
| 4 | * (C) Copyright 1996 Linus Torvalds |
Simon Arlott | c3a2dde | 2007-10-20 01:04:37 +0200 | [diff] [blame] | 5 | * accelerated versions (and 21264 assembly versions ) contributed by |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * Rick Gorton <rick.gorton@alpha-processor.com> |
| 7 | * |
| 8 | * Don't look at this too closely - you'll go mad. The things |
| 9 | * we do for performance.. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/string.h> |
| 14 | #include <asm/uaccess.h> |
| 15 | |
| 16 | |
| 17 | #define ldq_u(x,y) \ |
| 18 | __asm__ __volatile__("ldq_u %0,%1":"=r" (x):"m" (*(const unsigned long *)(y))) |
| 19 | |
| 20 | #define stq_u(x,y) \ |
| 21 | __asm__ __volatile__("stq_u %1,%0":"=m" (*(unsigned long *)(y)):"r" (x)) |
| 22 | |
| 23 | #define extql(x,y,z) \ |
| 24 | __asm__ __volatile__("extql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) |
| 25 | |
| 26 | #define extqh(x,y,z) \ |
| 27 | __asm__ __volatile__("extqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) |
| 28 | |
| 29 | #define mskql(x,y,z) \ |
| 30 | __asm__ __volatile__("mskql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) |
| 31 | |
| 32 | #define mskqh(x,y,z) \ |
| 33 | __asm__ __volatile__("mskqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) |
| 34 | |
| 35 | #define insql(x,y,z) \ |
| 36 | __asm__ __volatile__("insql %1,%2,%0":"=r" (z):"r" (x),"r" (y)) |
| 37 | |
| 38 | #define insqh(x,y,z) \ |
| 39 | __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y)) |
| 40 | |
| 41 | |
| 42 | #define __get_user_u(x,ptr) \ |
| 43 | ({ \ |
| 44 | long __guu_err; \ |
| 45 | __asm__ __volatile__( \ |
| 46 | "1: ldq_u %0,%2\n" \ |
| 47 | "2:\n" \ |
| 48 | ".section __ex_table,\"a\"\n" \ |
| 49 | " .long 1b - .\n" \ |
| 50 | " lda %0,2b-1b(%1)\n" \ |
| 51 | ".previous" \ |
| 52 | : "=r"(x), "=r"(__guu_err) \ |
| 53 | : "m"(__m(ptr)), "1"(0)); \ |
| 54 | __guu_err; \ |
| 55 | }) |
| 56 | |
| 57 | #define __put_user_u(x,ptr) \ |
| 58 | ({ \ |
| 59 | long __puu_err; \ |
| 60 | __asm__ __volatile__( \ |
| 61 | "1: stq_u %2,%1\n" \ |
| 62 | "2:\n" \ |
| 63 | ".section __ex_table,\"a\"\n" \ |
| 64 | " .long 1b - ." \ |
| 65 | " lda $31,2b-1b(%0)\n" \ |
| 66 | ".previous" \ |
| 67 | : "=r"(__puu_err) \ |
| 68 | : "m"(__m(addr)), "rJ"(x), "0"(0)); \ |
| 69 | __puu_err; \ |
| 70 | }) |
| 71 | |
| 72 | |
| 73 | static inline unsigned short from64to16(unsigned long x) |
| 74 | { |
| 75 | /* Using extract instructions is a bit more efficient |
| 76 | than the original shift/bitmask version. */ |
| 77 | |
| 78 | union { |
| 79 | unsigned long ul; |
| 80 | unsigned int ui[2]; |
| 81 | unsigned short us[4]; |
| 82 | } in_v, tmp_v, out_v; |
| 83 | |
| 84 | in_v.ul = x; |
| 85 | tmp_v.ul = (unsigned long) in_v.ui[0] + (unsigned long) in_v.ui[1]; |
| 86 | |
| 87 | /* Since the bits of tmp_v.sh[3] are going to always be zero, |
| 88 | we don't have to bother to add that in. */ |
| 89 | out_v.ul = (unsigned long) tmp_v.us[0] + (unsigned long) tmp_v.us[1] |
| 90 | + (unsigned long) tmp_v.us[2]; |
| 91 | |
| 92 | /* Similarly, out_v.us[2] is always zero for the final add. */ |
| 93 | return out_v.us[0] + out_v.us[1]; |
| 94 | } |
| 95 | |
| 96 | |
| 97 | |
| 98 | /* |
| 99 | * Ok. This isn't fun, but this is the EASY case. |
| 100 | */ |
| 101 | static inline unsigned long |
| 102 | csum_partial_cfu_aligned(const unsigned long __user *src, unsigned long *dst, |
| 103 | long len, unsigned long checksum, |
| 104 | int *errp) |
| 105 | { |
| 106 | unsigned long carry = 0; |
| 107 | int err = 0; |
| 108 | |
| 109 | while (len >= 0) { |
| 110 | unsigned long word; |
| 111 | err |= __get_user(word, src); |
| 112 | checksum += carry; |
| 113 | src++; |
| 114 | checksum += word; |
| 115 | len -= 8; |
| 116 | carry = checksum < word; |
| 117 | *dst = word; |
| 118 | dst++; |
| 119 | } |
| 120 | len += 8; |
| 121 | checksum += carry; |
| 122 | if (len) { |
| 123 | unsigned long word, tmp; |
| 124 | err |= __get_user(word, src); |
| 125 | tmp = *dst; |
| 126 | mskql(word, len, word); |
| 127 | checksum += word; |
| 128 | mskqh(tmp, len, tmp); |
| 129 | carry = checksum < word; |
| 130 | *dst = word | tmp; |
| 131 | checksum += carry; |
| 132 | } |
Jay Estabrook | 5cfe8f1 | 2013-11-16 16:45:31 -0800 | [diff] [blame] | 133 | if (err && errp) *errp = err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | return checksum; |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * This is even less fun, but this is still reasonably |
| 139 | * easy. |
| 140 | */ |
| 141 | static inline unsigned long |
| 142 | csum_partial_cfu_dest_aligned(const unsigned long __user *src, |
| 143 | unsigned long *dst, |
| 144 | unsigned long soff, |
| 145 | long len, unsigned long checksum, |
| 146 | int *errp) |
| 147 | { |
| 148 | unsigned long first; |
| 149 | unsigned long word, carry; |
| 150 | unsigned long lastsrc = 7+len+(unsigned long)src; |
| 151 | int err = 0; |
| 152 | |
| 153 | err |= __get_user_u(first,src); |
| 154 | carry = 0; |
| 155 | while (len >= 0) { |
| 156 | unsigned long second; |
| 157 | |
| 158 | err |= __get_user_u(second, src+1); |
| 159 | extql(first, soff, word); |
| 160 | len -= 8; |
| 161 | src++; |
| 162 | extqh(second, soff, first); |
| 163 | checksum += carry; |
| 164 | word |= first; |
| 165 | first = second; |
| 166 | checksum += word; |
| 167 | *dst = word; |
| 168 | dst++; |
| 169 | carry = checksum < word; |
| 170 | } |
| 171 | len += 8; |
| 172 | checksum += carry; |
| 173 | if (len) { |
| 174 | unsigned long tmp; |
| 175 | unsigned long second; |
| 176 | err |= __get_user_u(second, lastsrc); |
| 177 | tmp = *dst; |
| 178 | extql(first, soff, word); |
| 179 | extqh(second, soff, first); |
| 180 | word |= first; |
| 181 | mskql(word, len, word); |
| 182 | checksum += word; |
| 183 | mskqh(tmp, len, tmp); |
| 184 | carry = checksum < word; |
| 185 | *dst = word | tmp; |
| 186 | checksum += carry; |
| 187 | } |
Jay Estabrook | 5cfe8f1 | 2013-11-16 16:45:31 -0800 | [diff] [blame] | 188 | if (err && errp) *errp = err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | return checksum; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * This is slightly less fun than the above.. |
| 194 | */ |
| 195 | static inline unsigned long |
| 196 | csum_partial_cfu_src_aligned(const unsigned long __user *src, |
| 197 | unsigned long *dst, |
| 198 | unsigned long doff, |
| 199 | long len, unsigned long checksum, |
| 200 | unsigned long partial_dest, |
| 201 | int *errp) |
| 202 | { |
| 203 | unsigned long carry = 0; |
| 204 | unsigned long word; |
| 205 | unsigned long second_dest; |
| 206 | int err = 0; |
| 207 | |
| 208 | mskql(partial_dest, doff, partial_dest); |
| 209 | while (len >= 0) { |
| 210 | err |= __get_user(word, src); |
| 211 | len -= 8; |
| 212 | insql(word, doff, second_dest); |
| 213 | checksum += carry; |
| 214 | stq_u(partial_dest | second_dest, dst); |
| 215 | src++; |
| 216 | checksum += word; |
| 217 | insqh(word, doff, partial_dest); |
| 218 | carry = checksum < word; |
| 219 | dst++; |
| 220 | } |
| 221 | len += 8; |
| 222 | if (len) { |
| 223 | checksum += carry; |
| 224 | err |= __get_user(word, src); |
| 225 | mskql(word, len, word); |
| 226 | len -= 8; |
| 227 | checksum += word; |
| 228 | insql(word, doff, second_dest); |
| 229 | len += doff; |
| 230 | carry = checksum < word; |
| 231 | partial_dest |= second_dest; |
| 232 | if (len >= 0) { |
| 233 | stq_u(partial_dest, dst); |
| 234 | if (!len) goto out; |
| 235 | dst++; |
| 236 | insqh(word, doff, partial_dest); |
| 237 | } |
| 238 | doff = len; |
| 239 | } |
| 240 | ldq_u(second_dest, dst); |
| 241 | mskqh(second_dest, doff, second_dest); |
| 242 | stq_u(partial_dest | second_dest, dst); |
| 243 | out: |
| 244 | checksum += carry; |
Jay Estabrook | 5cfe8f1 | 2013-11-16 16:45:31 -0800 | [diff] [blame] | 245 | if (err && errp) *errp = err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | return checksum; |
| 247 | } |
| 248 | |
| 249 | /* |
| 250 | * This is so totally un-fun that it's frightening. Don't |
| 251 | * look at this too closely, you'll go blind. |
| 252 | */ |
| 253 | static inline unsigned long |
| 254 | csum_partial_cfu_unaligned(const unsigned long __user * src, |
| 255 | unsigned long * dst, |
| 256 | unsigned long soff, unsigned long doff, |
| 257 | long len, unsigned long checksum, |
| 258 | unsigned long partial_dest, |
| 259 | int *errp) |
| 260 | { |
| 261 | unsigned long carry = 0; |
| 262 | unsigned long first; |
| 263 | unsigned long lastsrc; |
| 264 | int err = 0; |
| 265 | |
| 266 | err |= __get_user_u(first, src); |
| 267 | lastsrc = 7+len+(unsigned long)src; |
| 268 | mskql(partial_dest, doff, partial_dest); |
| 269 | while (len >= 0) { |
| 270 | unsigned long second, word; |
| 271 | unsigned long second_dest; |
| 272 | |
| 273 | err |= __get_user_u(second, src+1); |
| 274 | extql(first, soff, word); |
| 275 | checksum += carry; |
| 276 | len -= 8; |
| 277 | extqh(second, soff, first); |
| 278 | src++; |
| 279 | word |= first; |
| 280 | first = second; |
| 281 | insql(word, doff, second_dest); |
| 282 | checksum += word; |
| 283 | stq_u(partial_dest | second_dest, dst); |
| 284 | carry = checksum < word; |
| 285 | insqh(word, doff, partial_dest); |
| 286 | dst++; |
| 287 | } |
| 288 | len += doff; |
| 289 | checksum += carry; |
| 290 | if (len >= 0) { |
| 291 | unsigned long second, word; |
| 292 | unsigned long second_dest; |
| 293 | |
| 294 | err |= __get_user_u(second, lastsrc); |
| 295 | extql(first, soff, word); |
| 296 | extqh(second, soff, first); |
| 297 | word |= first; |
| 298 | first = second; |
| 299 | mskql(word, len-doff, word); |
| 300 | checksum += word; |
| 301 | insql(word, doff, second_dest); |
| 302 | carry = checksum < word; |
| 303 | stq_u(partial_dest | second_dest, dst); |
| 304 | if (len) { |
| 305 | ldq_u(second_dest, dst+1); |
| 306 | insqh(word, doff, partial_dest); |
| 307 | mskqh(second_dest, len, second_dest); |
| 308 | stq_u(partial_dest | second_dest, dst+1); |
| 309 | } |
| 310 | checksum += carry; |
| 311 | } else { |
| 312 | unsigned long second, word; |
| 313 | unsigned long second_dest; |
| 314 | |
| 315 | err |= __get_user_u(second, lastsrc); |
| 316 | extql(first, soff, word); |
| 317 | extqh(second, soff, first); |
| 318 | word |= first; |
| 319 | ldq_u(second_dest, dst); |
| 320 | mskql(word, len-doff, word); |
| 321 | checksum += word; |
| 322 | mskqh(second_dest, len, second_dest); |
| 323 | carry = checksum < word; |
| 324 | insql(word, doff, word); |
| 325 | stq_u(partial_dest | word | second_dest, dst); |
| 326 | checksum += carry; |
| 327 | } |
Jay Estabrook | 5cfe8f1 | 2013-11-16 16:45:31 -0800 | [diff] [blame] | 328 | if (err && errp) *errp = err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | return checksum; |
| 330 | } |
| 331 | |
Al Viro | 9be259a | 2006-11-14 21:14:53 -0800 | [diff] [blame] | 332 | __wsum |
| 333 | csum_partial_copy_from_user(const void __user *src, void *dst, int len, |
| 334 | __wsum sum, int *errp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | { |
Al Viro | 9be259a | 2006-11-14 21:14:53 -0800 | [diff] [blame] | 336 | unsigned long checksum = (__force u32) sum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | unsigned long soff = 7 & (unsigned long) src; |
| 338 | unsigned long doff = 7 & (unsigned long) dst; |
| 339 | |
| 340 | if (len) { |
Mathieu Desnoyers | 3ddc5b4 | 2013-09-11 14:23:18 -0700 | [diff] [blame] | 341 | if (!access_ok(VERIFY_READ, src, len)) { |
Jay Estabrook | 5cfe8f1 | 2013-11-16 16:45:31 -0800 | [diff] [blame] | 342 | if (errp) *errp = -EFAULT; |
Mathieu Desnoyers | 3ddc5b4 | 2013-09-11 14:23:18 -0700 | [diff] [blame] | 343 | memset(dst, 0, len); |
| 344 | return sum; |
| 345 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | if (!doff) { |
| 347 | if (!soff) |
| 348 | checksum = csum_partial_cfu_aligned( |
| 349 | (const unsigned long __user *) src, |
| 350 | (unsigned long *) dst, |
| 351 | len-8, checksum, errp); |
| 352 | else |
| 353 | checksum = csum_partial_cfu_dest_aligned( |
| 354 | (const unsigned long __user *) src, |
| 355 | (unsigned long *) dst, |
| 356 | soff, len-8, checksum, errp); |
| 357 | } else { |
| 358 | unsigned long partial_dest; |
| 359 | ldq_u(partial_dest, dst); |
| 360 | if (!soff) |
| 361 | checksum = csum_partial_cfu_src_aligned( |
| 362 | (const unsigned long __user *) src, |
| 363 | (unsigned long *) dst, |
| 364 | doff, len-8, checksum, |
| 365 | partial_dest, errp); |
| 366 | else |
| 367 | checksum = csum_partial_cfu_unaligned( |
| 368 | (const unsigned long __user *) src, |
| 369 | (unsigned long *) dst, |
| 370 | soff, doff, len-8, checksum, |
| 371 | partial_dest, errp); |
| 372 | } |
| 373 | checksum = from64to16 (checksum); |
| 374 | } |
Al Viro | 9be259a | 2006-11-14 21:14:53 -0800 | [diff] [blame] | 375 | return (__force __wsum)checksum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 376 | } |
| 377 | |
Al Viro | 9be259a | 2006-11-14 21:14:53 -0800 | [diff] [blame] | 378 | __wsum |
| 379 | csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | { |
Mikulas Patocka | 0ef38d7 | 2014-01-22 23:04:33 -0500 | [diff] [blame] | 381 | __wsum checksum; |
| 382 | mm_segment_t oldfs = get_fs(); |
| 383 | set_fs(KERNEL_DS); |
| 384 | checksum = csum_partial_copy_from_user((__force const void __user *)src, |
| 385 | dst, len, sum, NULL); |
| 386 | set_fs(oldfs); |
| 387 | return checksum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | } |