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-rw-r--r--include/linux/hash.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/include/linux/hash.h b/include/linux/hash.h
index f09a0ae4d858..bd1754c7ecef 100644
--- a/include/linux/hash.h
+++ b/include/linux/hash.h
@@ -15,6 +15,7 @@
15 */ 15 */
16 16
17#include <asm/types.h> 17#include <asm/types.h>
18#include <asm/hash.h>
18#include <linux/compiler.h> 19#include <linux/compiler.h>
19 20
20/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */ 21/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
@@ -78,4 +79,39 @@ static inline u32 hash32_ptr(const void *ptr)
78#endif 79#endif
79 return (u32)val; 80 return (u32)val;
80} 81}
82
83struct fast_hash_ops {
84 u32 (*hash)(const void *data, u32 len, u32 seed);
85 u32 (*hash2)(const u32 *data, u32 len, u32 seed);
86};
87
88/**
89 * arch_fast_hash - Caclulates a hash over a given buffer that can have
90 * arbitrary size. This function will eventually use an
91 * architecture-optimized hashing implementation if
92 * available, and trades off distribution for speed.
93 *
94 * @data: buffer to hash
95 * @len: length of buffer in bytes
96 * @seed: start seed
97 *
98 * Returns 32bit hash.
99 */
100extern u32 arch_fast_hash(const void *data, u32 len, u32 seed);
101
102/**
103 * arch_fast_hash2 - Caclulates a hash over a given buffer that has a
104 * size that is of a multiple of 32bit words. This
105 * function will eventually use an architecture-
106 * optimized hashing implementation if available,
107 * and trades off distribution for speed.
108 *
109 * @data: buffer to hash (must be 32bit padded)
110 * @len: number of 32bit words
111 * @seed: start seed
112 *
113 * Returns 32bit hash.
114 */
115extern u32 arch_fast_hash2(const u32 *data, u32 len, u32 seed);
116
81#endif /* _LINUX_HASH_H */ 117#endif /* _LINUX_HASH_H */