text: /*
   * Lifted from 4.4 Linux kernel source. Alterations for netconsd:
   *	- Pulled in rol32() from linux/bitops.h
   *	- Use stdint fixed-width types instead of kernel shorthand types
   *	- Deleted unaligned jhash() because we don't use it and C++ hates it.
   */
  
  #ifndef _LINUX_JHASH_H
  #define _LINUX_JHASH_H
  
  /* jhash.h: Jenkins hash support.
   *
   * Copyright (C) 2006. Bob Jenkins (bob_jenkins@burtleburtle.net)
   *
   * http://burtleburtle.net/bob/hash/
   *
   * These are the credits from Bob's sources:
   *
   * lookup3.c, by Bob Jenkins, May 2006, Public Domain.
   *
   * These are functions for producing 32-bit hashes for hash table lookup.
   * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
   * are externally useful functions.  Routines to test the hash are included
   * if SELF_TEST is defined.  You can use this free for any purpose.  It's in
   * the public domain.  It has no warranty.
   *
   * Copyright (C) 2009-2010 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
   *
   * I've modified Bob's hash to be useful in the Linux kernel, and
   * any bugs present are my fault.
   * Jozsef
   */
  
  #include <stdint.h>
  
  static inline uint32_t rol32(uint32_t word, unsigned int shift)
  {
  	return (word << shift) | (word >> (32 - shift));
  }
  
  /* Best hash sizes are of power of two */
  #define jhash_size(n)   ((uint32_t)1<<(n))
  /* Mask the hash value, i.e (value & jhash_mask(n)) instead of (value % n) */
  #define jhash_mask(n)   (jhash_size(n)-1)
  
  /* __jhash_mix -- mix 3 32-bit values reversibly. */
  #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;	\
  }
  
  /* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */
  #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);		\
  }
  
  /*
   * Arbitrary initial parameters
   */
  #define JHASH_INITVAL	0xdeadbeef
  #define LISTEN_SEED	0xfaceb00c
  #define WORKER_SEED	0xb00cface
  
  /* jhash2 - hash an array of uint32_t's
   * @k: the key which must be an array of uint32_t's
   * @length: the number of uint32_t's in the key
   * @initval: the previous hash, or an arbitray value
   *
   * Returns the hash value of the key.
   */
  static inline __attribute__((pure)) uint32_t jhash2(const uint32_t *k,
  		uint32_t length, uint32_t initval)
  {
  	uint32_t a, b, c;
  
  	/* Set up the internal state */
  	a = b = c = JHASH_INITVAL + (length<<2) + initval;
  
  	/* Handle most of the key */
  	while (length > 3) {
  		a += k[0];
  		b += k[1];
  		c += k[2];
  		__jhash_mix(a, b, c);
  		length -= 3;
  		k += 3;
  	}
  
  	/* Handle the last 3 uint32_t's: all the case statements fall through */
  	switch (length) {
  	case 3: c += k[2];
  	case 2: b += k[1];
  	case 1: a += k[0];
  		__jhash_final(a, b, c);
  	case 0:	/* Nothing left to add */
  		break;
  	}
  
  	return c;
  }
  
  #endif /* _LINUX_JHASH_H */
  