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