1 /* 2 * Copyright (c) 2013 François Tigeot 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #ifndef _LINUX_HASH_H_ 28 #define _LINUX_HASH_H_ 29 30 #include <sys/hash.h> 31 32 static inline u64 hash_64(u64 val, unsigned int bits) 33 { 34 u64 ret; 35 36 ret = (uint64_t)hash32_buf(&val, sizeof(val), bits); 37 38 return ret >> (64 - bits); 39 } 40 41 static inline u32 hash_32(u32 val, unsigned int bits) 42 { 43 u32 ret; 44 45 ret = hash32_buf(&val, sizeof(val), bits); 46 47 return ret >> (32 - bits); 48 } 49 50 #if BITS_PER_LONG == 64 /* amd64 */ 51 #define hash_long(val, bits) hash_64(val, bits) 52 #else /* i386 */ 53 #define hash_long(val, bits) hash_32(val, bits) 54 #endif 55 56 #endif /* _LINUX_HASH_H_ */ 57