xref: /openbmc/u-boot/include/zfs/zap_leaf.h (revision 522de019)
1 /*
2  *  GRUB  --  GRand Unified Bootloader
3  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, write to the Free Software
17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18  */
19 /*
20  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
21  * Use is subject to license terms.
22  */
23 
24 #ifndef	_SYS_ZAP_LEAF_H
25 #define	_SYS_ZAP_LEAF_H
26 
27 #define	ZAP_LEAF_MAGIC 0x2AB1EAF
28 
29 /* chunk size = 24 bytes */
30 #define	ZAP_LEAF_CHUNKSIZE 24
31 
32 /*
33  * The amount of space within the chunk available for the array is:
34  * chunk size - space for type (1) - space for next pointer (2)
35  */
36 #define	ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3)
37 
38 typedef enum zap_chunk_type {
39 	ZAP_CHUNK_FREE = 253,
40 	ZAP_CHUNK_ENTRY = 252,
41 	ZAP_CHUNK_ARRAY = 251,
42 	ZAP_CHUNK_TYPE_MAX = 250
43 } zap_chunk_type_t;
44 
45 /*
46  * TAKE NOTE:
47  * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified.
48  */
49 typedef struct zap_leaf_phys {
50 	struct zap_leaf_header {
51 		uint64_t lh_block_type;		/* ZBT_LEAF */
52 		uint64_t lh_pad1;
53 		uint64_t lh_prefix;		/* hash prefix of this leaf */
54 		uint32_t lh_magic;		/* ZAP_LEAF_MAGIC */
55 		uint16_t lh_nfree;		/* number free chunks */
56 		uint16_t lh_nentries;		/* number of entries */
57 		uint16_t lh_prefix_len;		/* num bits used to id this */
58 
59 		/* above is accessable to zap, below is zap_leaf private */
60 
61 		uint16_t lh_freelist;		/* chunk head of free list */
62 		uint8_t lh_pad2[12];
63 	} l_hdr; /* 2 24-byte chunks */
64 
65 	/*
66 	 * The header is followed by a hash table with
67 	 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries.  The hash table is
68 	 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap)
69 	 * zap_leaf_chunk structures.  These structures are accessed
70 	 * with the ZAP_LEAF_CHUNK() macro.
71 	 */
72 
73 	uint16_t l_hash[1];
74 } zap_leaf_phys_t;
75 
76 typedef union zap_leaf_chunk {
77 	struct zap_leaf_entry {
78 		uint8_t le_type;		/* always ZAP_CHUNK_ENTRY */
79 		uint8_t le_int_size;		/* size of ints */
80 		uint16_t le_next;		/* next entry in hash chain */
81 		uint16_t le_name_chunk;		/* first chunk of the name */
82 		uint16_t le_name_length;	/* bytes in name, incl null */
83 		uint16_t le_value_chunk;	/* first chunk of the value */
84 		uint16_t le_value_length;	/* value length in ints */
85 		uint32_t le_cd;		/* collision differentiator */
86 		uint64_t le_hash;		/* hash value of the name */
87 	} l_entry;
88 	struct zap_leaf_array {
89 		uint8_t la_type;		/* always ZAP_CHUNK_ARRAY */
90 		union {
91 			uint8_t la_array[ZAP_LEAF_ARRAY_BYTES];
92 			uint64_t la_array64;
93 		} __attribute__ ((packed));
94 		uint16_t la_next;		/* next blk or CHAIN_END */
95 	} l_array;
96 	struct zap_leaf_free {
97 		uint8_t lf_type;		/* always ZAP_CHUNK_FREE */
98 		uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES];
99 		uint16_t lf_next;	/* next in free list, or CHAIN_END */
100 	} l_free;
101 } zap_leaf_chunk_t;
102 
103 #endif /* _SYS_ZAP_LEAF_H */
104