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1 | /*- |
2 | * BSD LICENSE | |
3 | * | |
4 | * Copyright(c) 2010-2015 Intel Corporation. All rights reserved. | |
5 | * All rights reserved. | |
6 | * | |
7 | * Redistribution and use in source and binary forms, with or without | |
8 | * modification, are permitted provided that the following conditions | |
9 | * are met: | |
10 | * | |
11 | * * Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * * Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in | |
15 | * the documentation and/or other materials provided with the | |
16 | * distribution. | |
17 | * * Neither the name of Intel Corporation nor the names of its | |
18 | * contributors may be used to endorse or promote products derived | |
19 | * from this software without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
22 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
23 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
24 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
25 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
26 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
27 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
28 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
29 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
30 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
31 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | #ifndef _RTE_JHASH_H | |
35 | #define _RTE_JHASH_H | |
36 | ||
37 | /** | |
38 | * @file | |
39 | * | |
40 | * jhash functions. | |
41 | */ | |
42 | ||
43 | #ifdef __cplusplus | |
44 | extern "C" { | |
45 | #endif | |
46 | ||
47 | #include <stdint.h> | |
48 | #include <string.h> | |
49 | #include <limits.h> | |
50 | ||
51 | #include <rte_log.h> | |
52 | #include <rte_byteorder.h> | |
53 | ||
54 | /* jhash.h: Jenkins hash support. | |
55 | * | |
56 | * Copyright (C) 2006 Bob Jenkins (bob_jenkins@burtleburtle.net) | |
57 | * | |
58 | * http://burtleburtle.net/bob/hash/ | |
59 | * | |
60 | * These are the credits from Bob's sources: | |
61 | * | |
62 | * lookup3.c, by Bob Jenkins, May 2006, Public Domain. | |
63 | * | |
64 | * These are functions for producing 32-bit hashes for hash table lookup. | |
65 | * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() | |
66 | * are externally useful functions. Routines to test the hash are included | |
67 | * if SELF_TEST is defined. You can use this free for any purpose. It's in | |
68 | * the public domain. It has no warranty. | |
69 | * | |
70 | * $FreeBSD$ | |
71 | */ | |
72 | ||
73 | #define rot(x, k) (((x) << (k)) | ((x) >> (32-(k)))) | |
74 | ||
75 | /** @internal Internal function. NOTE: Arguments are modified. */ | |
76 | #define __rte_jhash_mix(a, b, c) do { \ | |
77 | a -= c; a ^= rot(c, 4); c += b; \ | |
78 | b -= a; b ^= rot(a, 6); a += c; \ | |
79 | c -= b; c ^= rot(b, 8); b += a; \ | |
80 | a -= c; a ^= rot(c, 16); c += b; \ | |
81 | b -= a; b ^= rot(a, 19); a += c; \ | |
82 | c -= b; c ^= rot(b, 4); b += a; \ | |
83 | } while (0) | |
84 | ||
85 | #define __rte_jhash_final(a, b, c) do { \ | |
86 | c ^= b; c -= rot(b, 14); \ | |
87 | a ^= c; a -= rot(c, 11); \ | |
88 | b ^= a; b -= rot(a, 25); \ | |
89 | c ^= b; c -= rot(b, 16); \ | |
90 | a ^= c; a -= rot(c, 4); \ | |
91 | b ^= a; b -= rot(a, 14); \ | |
92 | c ^= b; c -= rot(b, 24); \ | |
93 | } while (0) | |
94 | ||
95 | /** The golden ratio: an arbitrary value. */ | |
96 | #define RTE_JHASH_GOLDEN_RATIO 0xdeadbeef | |
97 | ||
98 | #if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN | |
99 | #define BIT_SHIFT(x, y, k) (((x) >> (k)) | ((uint64_t)(y) << (32-(k)))) | |
100 | #else | |
101 | #define BIT_SHIFT(x, y, k) (((uint64_t)(x) << (k)) | ((y) >> (32-(k)))) | |
102 | #endif | |
103 | ||
104 | #define LOWER8b_MASK rte_le_to_cpu_32(0xff) | |
105 | #define LOWER16b_MASK rte_le_to_cpu_32(0xffff) | |
106 | #define LOWER24b_MASK rte_le_to_cpu_32(0xffffff) | |
107 | ||
108 | static inline void | |
109 | __rte_jhash_2hashes(const void *key, uint32_t length, uint32_t *pc, | |
110 | uint32_t *pb, unsigned check_align) | |
111 | { | |
112 | uint32_t a, b, c; | |
113 | ||
114 | /* Set up the internal state */ | |
115 | a = b = c = RTE_JHASH_GOLDEN_RATIO + ((uint32_t)length) + *pc; | |
116 | c += *pb; | |
117 | ||
118 | /* | |
119 | * Check key alignment. For x86 architecture, first case is always optimal | |
120 | * If check_align is not set, first case will be used | |
121 | */ | |
122 | #if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686) || defined(RTE_ARCH_X86_X32) | |
123 | const uint32_t *k = (const uint32_t *)key; | |
124 | const uint32_t s = 0; | |
125 | #else | |
126 | const uint32_t *k = (uint32_t *)((uintptr_t)key & (uintptr_t)~3); | |
127 | const uint32_t s = ((uintptr_t)key & 3) * CHAR_BIT; | |
128 | #endif | |
129 | if (!check_align || s == 0) { | |
130 | while (length > 12) { | |
131 | a += k[0]; | |
132 | b += k[1]; | |
133 | c += k[2]; | |
134 | ||
135 | __rte_jhash_mix(a, b, c); | |
136 | ||
137 | k += 3; | |
138 | length -= 12; | |
139 | } | |
140 | ||
141 | switch (length) { | |
142 | case 12: | |
143 | c += k[2]; b += k[1]; a += k[0]; break; | |
144 | case 11: | |
145 | c += k[2] & LOWER24b_MASK; b += k[1]; a += k[0]; break; | |
146 | case 10: | |
147 | c += k[2] & LOWER16b_MASK; b += k[1]; a += k[0]; break; | |
148 | case 9: | |
149 | c += k[2] & LOWER8b_MASK; b += k[1]; a += k[0]; break; | |
150 | case 8: | |
151 | b += k[1]; a += k[0]; break; | |
152 | case 7: | |
153 | b += k[1] & LOWER24b_MASK; a += k[0]; break; | |
154 | case 6: | |
155 | b += k[1] & LOWER16b_MASK; a += k[0]; break; | |
156 | case 5: | |
157 | b += k[1] & LOWER8b_MASK; a += k[0]; break; | |
158 | case 4: | |
159 | a += k[0]; break; | |
160 | case 3: | |
161 | a += k[0] & LOWER24b_MASK; break; | |
162 | case 2: | |
163 | a += k[0] & LOWER16b_MASK; break; | |
164 | case 1: | |
165 | a += k[0] & LOWER8b_MASK; break; | |
166 | /* zero length strings require no mixing */ | |
167 | case 0: | |
168 | *pc = c; | |
169 | *pb = b; | |
170 | return; | |
171 | }; | |
172 | } else { | |
173 | /* all but the last block: affect some 32 bits of (a, b, c) */ | |
174 | while (length > 12) { | |
175 | a += BIT_SHIFT(k[0], k[1], s); | |
176 | b += BIT_SHIFT(k[1], k[2], s); | |
177 | c += BIT_SHIFT(k[2], k[3], s); | |
178 | __rte_jhash_mix(a, b, c); | |
179 | ||
180 | k += 3; | |
181 | length -= 12; | |
182 | } | |
183 | ||
184 | /* last block: affect all 32 bits of (c) */ | |
185 | switch (length) { | |
186 | case 12: | |
187 | a += BIT_SHIFT(k[0], k[1], s); | |
188 | b += BIT_SHIFT(k[1], k[2], s); | |
189 | c += BIT_SHIFT(k[2], k[3], s); | |
190 | break; | |
191 | case 11: | |
192 | a += BIT_SHIFT(k[0], k[1], s); | |
193 | b += BIT_SHIFT(k[1], k[2], s); | |
194 | c += BIT_SHIFT(k[2], k[3], s) & LOWER24b_MASK; | |
195 | break; | |
196 | case 10: | |
197 | a += BIT_SHIFT(k[0], k[1], s); | |
198 | b += BIT_SHIFT(k[1], k[2], s); | |
199 | c += BIT_SHIFT(k[2], k[3], s) & LOWER16b_MASK; | |
200 | break; | |
201 | case 9: | |
202 | a += BIT_SHIFT(k[0], k[1], s); | |
203 | b += BIT_SHIFT(k[1], k[2], s); | |
204 | c += BIT_SHIFT(k[2], k[3], s) & LOWER8b_MASK; | |
205 | break; | |
206 | case 8: | |
207 | a += BIT_SHIFT(k[0], k[1], s); | |
208 | b += BIT_SHIFT(k[1], k[2], s); | |
209 | break; | |
210 | case 7: | |
211 | a += BIT_SHIFT(k[0], k[1], s); | |
212 | b += BIT_SHIFT(k[1], k[2], s) & LOWER24b_MASK; | |
213 | break; | |
214 | case 6: | |
215 | a += BIT_SHIFT(k[0], k[1], s); | |
216 | b += BIT_SHIFT(k[1], k[2], s) & LOWER16b_MASK; | |
217 | break; | |
218 | case 5: | |
219 | a += BIT_SHIFT(k[0], k[1], s); | |
220 | b += BIT_SHIFT(k[1], k[2], s) & LOWER8b_MASK; | |
221 | break; | |
222 | case 4: | |
223 | a += BIT_SHIFT(k[0], k[1], s); | |
224 | break; | |
225 | case 3: | |
226 | a += BIT_SHIFT(k[0], k[1], s) & LOWER24b_MASK; | |
227 | break; | |
228 | case 2: | |
229 | a += BIT_SHIFT(k[0], k[1], s) & LOWER16b_MASK; | |
230 | break; | |
231 | case 1: | |
232 | a += BIT_SHIFT(k[0], k[1], s) & LOWER8b_MASK; | |
233 | break; | |
234 | /* zero length strings require no mixing */ | |
235 | case 0: | |
236 | *pc = c; | |
237 | *pb = b; | |
238 | return; | |
239 | } | |
240 | } | |
241 | ||
242 | __rte_jhash_final(a, b, c); | |
243 | ||
244 | *pc = c; | |
245 | *pb = b; | |
246 | } | |
247 | ||
248 | /** | |
249 | * Same as rte_jhash, but takes two seeds and return two uint32_ts. | |
250 | * pc and pb must be non-null, and *pc and *pb must both be initialized | |
251 | * with seeds. If you pass in (*pb)=0, the output (*pc) will be | |
252 | * the same as the return value from rte_jhash. | |
253 | * | |
254 | * @param key | |
255 | * Key to calculate hash of. | |
256 | * @param length | |
257 | * Length of key in bytes. | |
258 | * @param pc | |
259 | * IN: seed OUT: primary hash value. | |
260 | * @param pb | |
261 | * IN: second seed OUT: secondary hash value. | |
262 | */ | |
263 | static inline void | |
264 | rte_jhash_2hashes(const void *key, uint32_t length, uint32_t *pc, uint32_t *pb) | |
265 | { | |
266 | __rte_jhash_2hashes(key, length, pc, pb, 1); | |
267 | } | |
268 | ||
269 | /** | |
270 | * Same as rte_jhash_32b, but takes two seeds and return two uint32_ts. | |
271 | * pc and pb must be non-null, and *pc and *pb must both be initialized | |
272 | * with seeds. If you pass in (*pb)=0, the output (*pc) will be | |
273 | * the same as the return value from rte_jhash_32b. | |
274 | * | |
275 | * @param k | |
276 | * Key to calculate hash of. | |
277 | * @param length | |
278 | * Length of key in units of 4 bytes. | |
279 | * @param pc | |
280 | * IN: seed OUT: primary hash value. | |
281 | * @param pb | |
282 | * IN: second seed OUT: secondary hash value. | |
283 | */ | |
284 | static inline void | |
285 | rte_jhash_32b_2hashes(const uint32_t *k, uint32_t length, uint32_t *pc, uint32_t *pb) | |
286 | { | |
287 | __rte_jhash_2hashes((const void *) k, (length << 2), pc, pb, 0); | |
288 | } | |
289 | ||
290 | /** | |
291 | * The most generic version, hashes an arbitrary sequence | |
292 | * of bytes. No alignment or length assumptions are made about | |
293 | * the input key. | |
294 | * | |
295 | * @param key | |
296 | * Key to calculate hash of. | |
297 | * @param length | |
298 | * Length of key in bytes. | |
299 | * @param initval | |
300 | * Initialising value of hash. | |
301 | * @return | |
302 | * Calculated hash value. | |
303 | */ | |
304 | static inline uint32_t | |
305 | rte_jhash(const void *key, uint32_t length, uint32_t initval) | |
306 | { | |
307 | uint32_t initval2 = 0; | |
308 | ||
309 | rte_jhash_2hashes(key, length, &initval, &initval2); | |
310 | ||
311 | return initval; | |
312 | } | |
313 | ||
314 | /** | |
315 | * A special optimized version that handles 1 or more of uint32_ts. | |
316 | * The length parameter here is the number of uint32_ts in the key. | |
317 | * | |
318 | * @param k | |
319 | * Key to calculate hash of. | |
320 | * @param length | |
321 | * Length of key in units of 4 bytes. | |
322 | * @param initval | |
323 | * Initialising value of hash. | |
324 | * @return | |
325 | * Calculated hash value. | |
326 | */ | |
327 | static inline uint32_t | |
328 | rte_jhash_32b(const uint32_t *k, uint32_t length, uint32_t initval) | |
329 | { | |
330 | uint32_t initval2 = 0; | |
331 | ||
332 | rte_jhash_32b_2hashes(k, length, &initval, &initval2); | |
333 | ||
334 | return initval; | |
335 | } | |
336 | ||
337 | static inline uint32_t | |
338 | __rte_jhash_3words(uint32_t a, uint32_t b, uint32_t c, uint32_t initval) | |
339 | { | |
340 | a += RTE_JHASH_GOLDEN_RATIO + initval; | |
341 | b += RTE_JHASH_GOLDEN_RATIO + initval; | |
342 | c += RTE_JHASH_GOLDEN_RATIO + initval; | |
343 | ||
344 | __rte_jhash_final(a, b, c); | |
345 | ||
346 | return c; | |
347 | } | |
348 | ||
349 | /** | |
350 | * A special ultra-optimized versions that knows it is hashing exactly | |
351 | * 3 words. | |
352 | * | |
353 | * @param a | |
354 | * First word to calculate hash of. | |
355 | * @param b | |
356 | * Second word to calculate hash of. | |
357 | * @param c | |
358 | * Third word to calculate hash of. | |
359 | * @param initval | |
360 | * Initialising value of hash. | |
361 | * @return | |
362 | * Calculated hash value. | |
363 | */ | |
364 | static inline uint32_t | |
365 | rte_jhash_3words(uint32_t a, uint32_t b, uint32_t c, uint32_t initval) | |
366 | { | |
367 | return __rte_jhash_3words(a + 12, b + 12, c + 12, initval); | |
368 | } | |
369 | ||
370 | /** | |
371 | * A special ultra-optimized versions that knows it is hashing exactly | |
372 | * 2 words. | |
373 | * | |
374 | * @param a | |
375 | * First word to calculate hash of. | |
376 | * @param b | |
377 | * Second word to calculate hash of. | |
378 | * @param initval | |
379 | * Initialising value of hash. | |
380 | * @return | |
381 | * Calculated hash value. | |
382 | */ | |
383 | static inline uint32_t | |
384 | rte_jhash_2words(uint32_t a, uint32_t b, uint32_t initval) | |
385 | { | |
386 | return __rte_jhash_3words(a + 8, b + 8, 8, initval); | |
387 | } | |
388 | ||
389 | /** | |
390 | * A special ultra-optimized versions that knows it is hashing exactly | |
391 | * 1 word. | |
392 | * | |
393 | * @param a | |
394 | * Word to calculate hash of. | |
395 | * @param initval | |
396 | * Initialising value of hash. | |
397 | * @return | |
398 | * Calculated hash value. | |
399 | */ | |
400 | static inline uint32_t | |
401 | rte_jhash_1word(uint32_t a, uint32_t initval) | |
402 | { | |
403 | return __rte_jhash_3words(a + 4, 4, 4, initval); | |
404 | } | |
405 | ||
406 | #ifdef __cplusplus | |
407 | } | |
408 | #endif | |
409 | ||
410 | #endif /* _RTE_JHASH_H */ |