// SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2019 Facebook typedef unsigned int u32; static __attribute__((always_inline)) u32 rol32(u32 word, unsigned int shift) { return (word << shift) | (word >> ((-shift) & 31)); } #define __jhash_mix(a, b, c) \ { \ a -= c; a ^= rol32(c, 4); c += b; \ b -= a; b ^= rol32(a, 6); a += c; \ c -= b; c ^= rol32(b, 8); b += a; \ a -= c; a ^= rol32(c, 16); c += b; \ b -= a; b ^= rol32(a, 19); a += c; \ c -= b; c ^= rol32(b, 4); b += a; \ } #define __jhash_final(a, b, c) \ { \ c ^= b; c -= rol32(b, 14); \ a ^= c; a -= rol32(c, 11); \ b ^= a; b -= rol32(a, 25); \ c ^= b; c -= rol32(b, 16); \ a ^= c; a -= rol32(c, 4); \ b ^= a; b -= rol32(a, 14); \ c ^= b; c -= rol32(b, 24); \ } #define JHASH_INITVAL 0xdeadbeef static ATTR u32 jhash(const void *key, u32 length, u32 initval) { u32 a, b, c; const unsigned char *k = key; a = b = c = JHASH_INITVAL + length + initval; while (length > 12) { a += *(volatile u32 *)(k); b += *(volatile u32 *)(k + 4); c += *(volatile u32 *)(k + 8); __jhash_mix(a, b, c); length -= 12; k += 12; } switch (length) { case 12: c += (u32)k[11]<<24; case 11: c += (u32)k[10]<<16; case 10: c += (u32)k[9]<<8; case 9: c += k[8]; case 8: b += (u32)k[7]<<24; case 7: b += (u32)k[6]<<16; case 6: b += (u32)k[5]<<8; case 5: b += k[4]; case 4: a += (u32)k[3]<<24; case 3: a += (u32)k[2]<<16; case 2: a += (u32)k[1]<<8; case 1: a += k[0]; c ^= a; __jhash_final(a, b, c); case 0: /* Nothing left to add */ break; } return c; }