1
2#ifdef __KERNEL__
3# include <linux/crush/hash.h>
4#else
5# include "hash.h"
6#endif
7
8
9
10
11
12
13#define crush_hashmix(a, b, c) do { \
14 a = a-b; a = a-c; a = a^(c>>13); \
15 b = b-c; b = b-a; b = b^(a<<8); \
16 c = c-a; c = c-b; c = c^(b>>13); \
17 a = a-b; a = a-c; a = a^(c>>12); \
18 b = b-c; b = b-a; b = b^(a<<16); \
19 c = c-a; c = c-b; c = c^(b>>5); \
20 a = a-b; a = a-c; a = a^(c>>3); \
21 b = b-c; b = b-a; b = b^(a<<10); \
22 c = c-a; c = c-b; c = c^(b>>15); \
23 } while (0)
24
25#define crush_hash_seed 1315423911
26
27static __u32 crush_hash32_rjenkins1(__u32 a)
28{
29 __u32 hash = crush_hash_seed ^ a;
30 __u32 b = a;
31 __u32 x = 231232;
32 __u32 y = 1232;
33 crush_hashmix(b, x, hash);
34 crush_hashmix(y, a, hash);
35 return hash;
36}
37
38static __u32 crush_hash32_rjenkins1_2(__u32 a, __u32 b)
39{
40 __u32 hash = crush_hash_seed ^ a ^ b;
41 __u32 x = 231232;
42 __u32 y = 1232;
43 crush_hashmix(a, b, hash);
44 crush_hashmix(x, a, hash);
45 crush_hashmix(b, y, hash);
46 return hash;
47}
48
49static __u32 crush_hash32_rjenkins1_3(__u32 a, __u32 b, __u32 c)
50{
51 __u32 hash = crush_hash_seed ^ a ^ b ^ c;
52 __u32 x = 231232;
53 __u32 y = 1232;
54 crush_hashmix(a, b, hash);
55 crush_hashmix(c, x, hash);
56 crush_hashmix(y, a, hash);
57 crush_hashmix(b, x, hash);
58 crush_hashmix(y, c, hash);
59 return hash;
60}
61
62static __u32 crush_hash32_rjenkins1_4(__u32 a, __u32 b, __u32 c, __u32 d)
63{
64 __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d;
65 __u32 x = 231232;
66 __u32 y = 1232;
67 crush_hashmix(a, b, hash);
68 crush_hashmix(c, d, hash);
69 crush_hashmix(a, x, hash);
70 crush_hashmix(y, b, hash);
71 crush_hashmix(c, x, hash);
72 crush_hashmix(y, d, hash);
73 return hash;
74}
75
76static __u32 crush_hash32_rjenkins1_5(__u32 a, __u32 b, __u32 c, __u32 d,
77 __u32 e)
78{
79 __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d ^ e;
80 __u32 x = 231232;
81 __u32 y = 1232;
82 crush_hashmix(a, b, hash);
83 crush_hashmix(c, d, hash);
84 crush_hashmix(e, x, hash);
85 crush_hashmix(y, a, hash);
86 crush_hashmix(b, x, hash);
87 crush_hashmix(y, c, hash);
88 crush_hashmix(d, x, hash);
89 crush_hashmix(y, e, hash);
90 return hash;
91}
92
93
94__u32 crush_hash32(int type, __u32 a)
95{
96 switch (type) {
97 case CRUSH_HASH_RJENKINS1:
98 return crush_hash32_rjenkins1(a);
99 default:
100 return 0;
101 }
102}
103
104__u32 crush_hash32_2(int type, __u32 a, __u32 b)
105{
106 switch (type) {
107 case CRUSH_HASH_RJENKINS1:
108 return crush_hash32_rjenkins1_2(a, b);
109 default:
110 return 0;
111 }
112}
113
114__u32 crush_hash32_3(int type, __u32 a, __u32 b, __u32 c)
115{
116 switch (type) {
117 case CRUSH_HASH_RJENKINS1:
118 return crush_hash32_rjenkins1_3(a, b, c);
119 default:
120 return 0;
121 }
122}
123
124__u32 crush_hash32_4(int type, __u32 a, __u32 b, __u32 c, __u32 d)
125{
126 switch (type) {
127 case CRUSH_HASH_RJENKINS1:
128 return crush_hash32_rjenkins1_4(a, b, c, d);
129 default:
130 return 0;
131 }
132}
133
134__u32 crush_hash32_5(int type, __u32 a, __u32 b, __u32 c, __u32 d, __u32 e)
135{
136 switch (type) {
137 case CRUSH_HASH_RJENKINS1:
138 return crush_hash32_rjenkins1_5(a, b, c, d, e);
139 default:
140 return 0;
141 }
142}
143
144const char *crush_hash_name(int type)
145{
146 switch (type) {
147 case CRUSH_HASH_RJENKINS1:
148 return "rjenkins1";
149 default:
150 return "unknown";
151 }
152}
153
