mirror of https://gitee.com/openkylin/linux.git
153 lines
3.2 KiB
C
153 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#ifdef __KERNEL__
|
|
# include <linux/crush/hash.h>
|
|
#else
|
|
# include "hash.h"
|
|
#endif
|
|
|
|
/*
|
|
* Robert Jenkins' function for mixing 32-bit values
|
|
* https://burtleburtle.net/bob/hash/evahash.html
|
|
* a, b = random bits, c = input and output
|
|
*/
|
|
#define crush_hashmix(a, b, c) do { \
|
|
a = a-b; a = a-c; a = a^(c>>13); \
|
|
b = b-c; b = b-a; b = b^(a<<8); \
|
|
c = c-a; c = c-b; c = c^(b>>13); \
|
|
a = a-b; a = a-c; a = a^(c>>12); \
|
|
b = b-c; b = b-a; b = b^(a<<16); \
|
|
c = c-a; c = c-b; c = c^(b>>5); \
|
|
a = a-b; a = a-c; a = a^(c>>3); \
|
|
b = b-c; b = b-a; b = b^(a<<10); \
|
|
c = c-a; c = c-b; c = c^(b>>15); \
|
|
} while (0)
|
|
|
|
#define crush_hash_seed 1315423911
|
|
|
|
static __u32 crush_hash32_rjenkins1(__u32 a)
|
|
{
|
|
__u32 hash = crush_hash_seed ^ a;
|
|
__u32 b = a;
|
|
__u32 x = 231232;
|
|
__u32 y = 1232;
|
|
crush_hashmix(b, x, hash);
|
|
crush_hashmix(y, a, hash);
|
|
return hash;
|
|
}
|
|
|
|
static __u32 crush_hash32_rjenkins1_2(__u32 a, __u32 b)
|
|
{
|
|
__u32 hash = crush_hash_seed ^ a ^ b;
|
|
__u32 x = 231232;
|
|
__u32 y = 1232;
|
|
crush_hashmix(a, b, hash);
|
|
crush_hashmix(x, a, hash);
|
|
crush_hashmix(b, y, hash);
|
|
return hash;
|
|
}
|
|
|
|
static __u32 crush_hash32_rjenkins1_3(__u32 a, __u32 b, __u32 c)
|
|
{
|
|
__u32 hash = crush_hash_seed ^ a ^ b ^ c;
|
|
__u32 x = 231232;
|
|
__u32 y = 1232;
|
|
crush_hashmix(a, b, hash);
|
|
crush_hashmix(c, x, hash);
|
|
crush_hashmix(y, a, hash);
|
|
crush_hashmix(b, x, hash);
|
|
crush_hashmix(y, c, hash);
|
|
return hash;
|
|
}
|
|
|
|
static __u32 crush_hash32_rjenkins1_4(__u32 a, __u32 b, __u32 c, __u32 d)
|
|
{
|
|
__u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d;
|
|
__u32 x = 231232;
|
|
__u32 y = 1232;
|
|
crush_hashmix(a, b, hash);
|
|
crush_hashmix(c, d, hash);
|
|
crush_hashmix(a, x, hash);
|
|
crush_hashmix(y, b, hash);
|
|
crush_hashmix(c, x, hash);
|
|
crush_hashmix(y, d, hash);
|
|
return hash;
|
|
}
|
|
|
|
static __u32 crush_hash32_rjenkins1_5(__u32 a, __u32 b, __u32 c, __u32 d,
|
|
__u32 e)
|
|
{
|
|
__u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d ^ e;
|
|
__u32 x = 231232;
|
|
__u32 y = 1232;
|
|
crush_hashmix(a, b, hash);
|
|
crush_hashmix(c, d, hash);
|
|
crush_hashmix(e, x, hash);
|
|
crush_hashmix(y, a, hash);
|
|
crush_hashmix(b, x, hash);
|
|
crush_hashmix(y, c, hash);
|
|
crush_hashmix(d, x, hash);
|
|
crush_hashmix(y, e, hash);
|
|
return hash;
|
|
}
|
|
|
|
|
|
__u32 crush_hash32(int type, __u32 a)
|
|
{
|
|
switch (type) {
|
|
case CRUSH_HASH_RJENKINS1:
|
|
return crush_hash32_rjenkins1(a);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
__u32 crush_hash32_2(int type, __u32 a, __u32 b)
|
|
{
|
|
switch (type) {
|
|
case CRUSH_HASH_RJENKINS1:
|
|
return crush_hash32_rjenkins1_2(a, b);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
__u32 crush_hash32_3(int type, __u32 a, __u32 b, __u32 c)
|
|
{
|
|
switch (type) {
|
|
case CRUSH_HASH_RJENKINS1:
|
|
return crush_hash32_rjenkins1_3(a, b, c);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
__u32 crush_hash32_4(int type, __u32 a, __u32 b, __u32 c, __u32 d)
|
|
{
|
|
switch (type) {
|
|
case CRUSH_HASH_RJENKINS1:
|
|
return crush_hash32_rjenkins1_4(a, b, c, d);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
__u32 crush_hash32_5(int type, __u32 a, __u32 b, __u32 c, __u32 d, __u32 e)
|
|
{
|
|
switch (type) {
|
|
case CRUSH_HASH_RJENKINS1:
|
|
return crush_hash32_rjenkins1_5(a, b, c, d, e);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
const char *crush_hash_name(int type)
|
|
{
|
|
switch (type) {
|
|
case CRUSH_HASH_RJENKINS1:
|
|
return "rjenkins1";
|
|
default:
|
|
return "unknown";
|
|
}
|
|
}
|