ns/sdbc/sd_hash.h

	sd_hash.h revision fcf3ce441efd61da9bb2884968af01cb7c1452cc
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _SD_HASH_H
#define _SD_HASH_H

#ifdef  __cplusplus
extern "C" {
#endif

#include <sys/nsctl/nsctl.h>

#if defined(_KERNEL) || defined(_KMEMUSER)

typedef struct _sd_hash_hd {
    unsigned short hh_hashed;       /* Is this block in hash */
    unsigned short hh_cd;           /* The cache descriptor */
    nsc_off_t hh_blk_num;           /* Cache block number   */
    struct _sd_hash_hd *hh_prev;        /* for chaining withing */
    struct _sd_hash_hd *hh_next;        /* hash table       */
} _sd_hash_hd_t;


typedef struct _sd_hash_bucket {
    struct _sd_hash_hd *hb_head;
    struct _sd_hash_hd *hb_tail;
    kmutex_t *hb_lock;
    unsigned short hb_inlist;
    volatile unsigned int hb_seq;
} _sd_hash_bucket_t;


typedef struct _sd_hash_table  {
    int ht_size;
    int ht_bits;
    int ht_mask;
    int ht_nmask;
    struct _sd_hash_bucket *ht_buckets;
} _sd_hash_table_t;


#endif /* _KERNEL && _KMEMUSER */


#if defined(_KERNEL)

#define HASH(cd, blk, table) \
    (((cd << 6) ^ ((blk) ^ ((blk) >> table->ht_bits)))  \
        & (table->ht_mask))

#define HT_SEARCH   0
#define HT_NOSEARCH 1

extern int _sdbc_hash_load(void);
extern void _sdbc_hash_unload(void);
extern _sd_hash_table_t *_sdbc_hash_configure(int num_ents);
extern void _sdbc_hash_deconfigure(_sd_hash_table_t *hash_table);
extern _sd_hash_hd_t *_sd_hash_search(int cd, nsc_off_t block_num,
    _sd_hash_table_t *table);
extern _sd_hash_hd_t *_sd_hash_insert(int cd, nsc_off_t block_num,
    _sd_hash_hd_t *hptr, _sd_hash_table_t *table);
extern int _sd_hash_delete(_sd_hash_hd_t *hptr, _sd_hash_table_t *table);
extern _sd_hash_hd_t *_sd_hash_replace(_sd_hash_hd_t *old, _sd_hash_hd_t *new,
    _sd_hash_table_t *table);
#endif /* _KERNEL */

#ifdef  __cplusplus
}
#endif

#endif /* _SD_HASH_H */