diff options
Diffstat (limited to 'target/linux/generic/patches-2.6.37/201-jhash3.patch')
| -rw-r--r-- | target/linux/generic/patches-2.6.37/201-jhash3.patch | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/target/linux/generic/patches-2.6.37/201-jhash3.patch b/target/linux/generic/patches-2.6.37/201-jhash3.patch new file mode 100644 index 0000000000..2dd14149c5 --- /dev/null +++ b/target/linux/generic/patches-2.6.37/201-jhash3.patch @@ -0,0 +1,227 @@ +--- a/include/linux/jhash.h ++++ b/include/linux/jhash.h +@@ -3,80 +3,95 @@ + + /* jhash.h: Jenkins hash support. + * +- * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net) ++ * Copyright (C) 2006. Bob Jenkins (bob_jenkins@burtleburtle.net) + * + * http://burtleburtle.net/bob/hash/ + * + * These are the credits from Bob's sources: + * +- * lookup2.c, by Bob Jenkins, December 1996, Public Domain. +- * hash(), hash2(), hash3, and mix() 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 has no warranty. ++ * lookup3.c, by Bob Jenkins, May 2006, Public Domain. + * +- * Copyright (C) 2003 David S. Miller (davem@redhat.com) ++ * 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 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu) + * + * I've modified Bob's hash to be useful in the Linux kernel, and +- * any bugs present are surely my fault. -DaveM ++ * any bugs present are my fault. Jozsef + */ + +-/* NOTE: Arguments are modified. */ +-#define __jhash_mix(a, b, c) \ ++#define __rot(x,k) (((x)<<(k)) | ((x)>>(32-(k)))) ++ ++/* __jhash_mix - mix 3 32-bit values reversibly. */ ++#define __jhash_mix(a,b,c) \ + { \ +- a -= b; a -= c; a ^= (c>>13); \ +- b -= c; b -= a; b ^= (a<<8); \ +- c -= a; c -= b; c ^= (b>>13); \ +- a -= b; a -= c; a ^= (c>>12); \ +- b -= c; b -= a; b ^= (a<<16); \ +- c -= a; c -= b; c ^= (b>>5); \ +- a -= b; a -= c; a ^= (c>>3); \ +- b -= c; b -= a; b ^= (a<<10); \ +- c -= a; c -= b; c ^= (b>>15); \ ++ a -= c; a ^= __rot(c, 4); c += b; \ ++ b -= a; b ^= __rot(a, 6); a += c; \ ++ c -= b; c ^= __rot(b, 8); b += a; \ ++ a -= c; a ^= __rot(c,16); c += b; \ ++ b -= a; b ^= __rot(a,19); a += c; \ ++ c -= b; c ^= __rot(b, 4); b += a; \ + } + +-/* The golden ration: an arbitrary value */ +-#define JHASH_GOLDEN_RATIO 0x9e3779b9 ++/* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */ ++#define __jhash_final(a,b,c) \ ++{ \ ++ c ^= b; c -= __rot(b,14); \ ++ a ^= c; a -= __rot(c,11); \ ++ b ^= a; b -= __rot(a,25); \ ++ c ^= b; c -= __rot(b,16); \ ++ a ^= c; a -= __rot(c,4); \ ++ b ^= a; b -= __rot(a,14); \ ++ c ^= b; c -= __rot(b,24); \ ++} ++ ++/* An arbitrary initial parameter */ ++#define JHASH_GOLDEN_RATIO 0xdeadbeef + + /* The most generic version, hashes an arbitrary sequence + * of bytes. No alignment or length assumptions are made about +- * the input key. ++ * the input key. The result depends on endianness. + */ + static inline u32 jhash(const void *key, u32 length, u32 initval) + { +- u32 a, b, c, len; ++ u32 a,b,c; + const u8 *k = key; + +- len = length; +- a = b = JHASH_GOLDEN_RATIO; +- c = initval; +- +- while (len >= 12) { +- a += (k[0] +((u32)k[1]<<8) +((u32)k[2]<<16) +((u32)k[3]<<24)); +- b += (k[4] +((u32)k[5]<<8) +((u32)k[6]<<16) +((u32)k[7]<<24)); +- c += (k[8] +((u32)k[9]<<8) +((u32)k[10]<<16)+((u32)k[11]<<24)); +- +- __jhash_mix(a,b,c); ++ /* Set up the internal state */ ++ a = b = c = JHASH_GOLDEN_RATIO + length + initval; + ++ /* all but the last block: affect some 32 bits of (a,b,c) */ ++ while (length > 12) { ++ a += (k[0] + ((u32)k[1]<<8) + ((u32)k[2]<<16) + ((u32)k[3]<<24)); ++ b += (k[4] + ((u32)k[5]<<8) + ((u32)k[6]<<16) + ((u32)k[7]<<24)); ++ c += (k[8] + ((u32)k[9]<<8) + ((u32)k[10]<<16) + ((u32)k[11]<<24)); ++ __jhash_mix(a, b, c); ++ length -= 12; + k += 12; +- len -= 12; + } + +- c += length; +- switch (len) { +- case 11: c += ((u32)k[10]<<24); +- case 10: c += ((u32)k[9]<<16); +- case 9 : c += ((u32)k[8]<<8); +- case 8 : b += ((u32)k[7]<<24); +- case 7 : b += ((u32)k[6]<<16); +- case 6 : b += ((u32)k[5]<<8); ++ /* last block: affect all 32 bits of (c) */ ++ /* all the case statements fall through */ ++ 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 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]; +- }; +- +- __jhash_mix(a,b,c); ++ __jhash_final(a, b, c); ++ case 0 : ++ break; ++ } + + return c; + } +@@ -86,28 +101,31 @@ static inline u32 jhash(const void *key, + */ + static inline u32 jhash2(const u32 *k, u32 length, u32 initval) + { +- u32 a, b, c, len; ++ u32 a, b, c; + +- a = b = JHASH_GOLDEN_RATIO; +- c = initval; +- len = length; ++ /* Set up the internal state */ ++ a = b = c = JHASH_GOLDEN_RATIO + (length<<2) + initval; + +- while (len >= 3) { ++ /* handle most of the key */ ++ while (length > 3) { + a += k[0]; + b += k[1]; + c += k[2]; + __jhash_mix(a, b, c); +- k += 3; len -= 3; ++ length -= 3; ++ k += 3; + } + +- c += length * 4; +- +- switch (len) { +- case 2 : b += k[1]; +- case 1 : a += k[0]; +- }; +- +- __jhash_mix(a,b,c); ++ /* handle the last 3 u32'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: /* case 0: nothing left to add */ ++ break; ++ } + + return c; + } +@@ -115,29 +133,26 @@ static inline u32 jhash2(const u32 *k, u + + /* A special ultra-optimized versions that knows they are hashing exactly + * 3, 2 or 1 word(s). +- * +- * NOTE: In particular the "c += length; __jhash_mix(a,b,c);" normally +- * done at the end is not done here. + */ + static inline u32 jhash_3words(u32 a, u32 b, u32 c, u32 initval) + { +- a += JHASH_GOLDEN_RATIO; +- b += JHASH_GOLDEN_RATIO; +- c += initval; ++ a += JHASH_GOLDEN_RATIO + initval; ++ b += JHASH_GOLDEN_RATIO + initval; ++ c += JHASH_GOLDEN_RATIO + initval; + +- __jhash_mix(a, b, c); ++ __jhash_final(a, b, c); + + return c; + } + + static inline u32 jhash_2words(u32 a, u32 b, u32 initval) + { +- return jhash_3words(a, b, 0, initval); ++ return jhash_3words(0, a, b, initval); + } + + static inline u32 jhash_1word(u32 a, u32 initval) + { +- return jhash_3words(a, 0, 0, initval); ++ return jhash_3words(0, 0, a, initval); + } + + #endif /* _LINUX_JHASH_H */ |