1 /* 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2022 NVIDIA corporation & affiliates. 5 * Copyright (c) 2013 François Tigeot 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 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions, and the following 12 * disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #ifndef _LINUXKPI_LINUX_HASH_H_ 30 #define _LINUXKPI_LINUX_HASH_H_ 31 32 #include <sys/hash.h> 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 36 #include <asm/types.h> 37 38 #include <linux/bitops.h> 39 40 static inline u64 41 hash_64(u64 val, u8 bits) 42 { 43 u64 ret; 44 u8 x; 45 46 ret = bits; 47 48 for (x = 0; x != sizeof(ret); x++) { 49 u64 chunk = (val >> (8 * x)) & 0xFF; 50 ret = HASHSTEP(ret, chunk); 51 } 52 return (ret >> (64 - bits)); 53 } 54 55 static inline u32 56 hash_32(u32 val, u8 bits) 57 { 58 u32 ret; 59 u8 x; 60 61 ret = bits; 62 63 for (x = 0; x != sizeof(ret); x++) { 64 u32 chunk = (val >> (8 * x)) & 0xFF; 65 ret = HASHSTEP(ret, chunk); 66 } 67 return (ret >> (32 - bits)); 68 } 69 70 #if BITS_PER_LONG == 64 71 #define hash_long(...) hash_64(__VA_ARGS__) 72 #else 73 #define hash_long(...) hash_32(__VA_ARGS__) 74 #endif 75 76 #endif /* _LINUXKPI_LINUX_HASH_H_ */ 77