xref: /OK3568_Linux_fs/kernel/drivers/md/persistent-data/dm-persistent-data-internal.h (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright (C) 2011 Red Hat, Inc.
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * This file is released under the GPL.
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #ifndef _DM_PERSISTENT_DATA_INTERNAL_H
8*4882a593Smuzhiyun #define _DM_PERSISTENT_DATA_INTERNAL_H
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun #include "dm-block-manager.h"
11*4882a593Smuzhiyun 
dm_hash_block(dm_block_t b,unsigned hash_mask)12*4882a593Smuzhiyun static inline unsigned dm_hash_block(dm_block_t b, unsigned hash_mask)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun 	const unsigned BIG_PRIME = 4294967291UL;
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun 	return (((unsigned) b) * BIG_PRIME) & hash_mask;
17*4882a593Smuzhiyun }
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun #endif	/* _PERSISTENT_DATA_INTERNAL_H */
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