xref: /openbmc/u-boot/include/zfs/zap_impl.h (revision 713cb680)
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 (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
21  */
22 
23 #ifndef	_SYS_ZAP_IMPL_H
24 #define	_SYS_ZAP_IMPL_H
25 
26 #define	ZAP_MAGIC 0x2F52AB2ABULL
27 
28 #define	ZAP_HASHBITS		28
29 #define	MZAP_ENT_LEN		64
30 #define	MZAP_NAME_LEN		(MZAP_ENT_LEN - 8 - 4 - 2)
31 #define	MZAP_MAX_BLKSHIFT	SPA_MAXBLOCKSHIFT
32 #define	MZAP_MAX_BLKSZ		(1 << MZAP_MAX_BLKSHIFT)
33 
34 typedef struct mzap_ent_phys {
35 	uint64_t mze_value;
36 	uint32_t mze_cd;
37 	uint16_t mze_pad;	/* in case we want to chain them someday */
38 	char mze_name[MZAP_NAME_LEN];
39 } mzap_ent_phys_t;
40 
41 typedef struct mzap_phys {
42 	uint64_t mz_block_type;	/* ZBT_MICRO */
43 	uint64_t mz_salt;
44 	uint64_t mz_pad[6];
45 	mzap_ent_phys_t mz_chunk[1];
46 	/* actually variable size depending on block size */
47 } mzap_phys_t;
48 
49 /*
50  * The (fat) zap is stored in one object. It is an array of
51  * 1<<FZAP_BLOCK_SHIFT byte blocks. The layout looks like one of:
52  *
53  * ptrtbl fits in first block:
54  *	[zap_phys_t zap_ptrtbl_shift < 6] [zap_leaf_t] ...
55  *
56  * ptrtbl too big for first block:
57  *	[zap_phys_t zap_ptrtbl_shift >= 6] [zap_leaf_t] [ptrtbl] ...
58  *
59  */
60 
61 #define	ZBT_LEAF		((1ULL << 63) + 0)
62 #define	ZBT_HEADER		((1ULL << 63) + 1)
63 #define	ZBT_MICRO		((1ULL << 63) + 3)
64 /* any other values are ptrtbl blocks */
65 
66 /*
67  * the embedded pointer table takes up half a block:
68  * block size / entry size (2^3) / 2
69  */
70 #define	ZAP_EMBEDDED_PTRTBL_SHIFT(zap) (FZAP_BLOCK_SHIFT(zap) - 3 - 1)
71 
72 /*
73  * The embedded pointer table starts half-way through the block.  Since
74  * the pointer table itself is half the block, it starts at (64-bit)
75  * word number (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)).
76  */
77 #define	ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) \
78 	((uint64_t *)(zap)->zap_f.zap_phys) \
79 	[(idx) + (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap))]
80 
81 /*
82  * TAKE NOTE:
83  * If zap_phys_t is modified, zap_byteswap() must be modified.
84  */
85 typedef struct zap_phys {
86 	uint64_t zap_block_type;	/* ZBT_HEADER */
87 	uint64_t zap_magic;		/* ZAP_MAGIC */
88 
89 	struct zap_table_phys {
90 		uint64_t zt_blk;	/* starting block number */
91 		uint64_t zt_numblks;	/* number of blocks */
92 		uint64_t zt_shift;	/* bits to index it */
93 		uint64_t zt_nextblk;	/* next (larger) copy start block */
94 		uint64_t zt_blks_copied; /* number source blocks copied */
95 	} zap_ptrtbl;
96 
97 	uint64_t zap_freeblk;		/* the next free block */
98 	uint64_t zap_num_leafs;		/* number of leafs */
99 	uint64_t zap_num_entries;	/* number of entries */
100 	uint64_t zap_salt;		/* salt to stir into hash function */
101 	uint64_t zap_normflags;		/* flags for u8_textprep_str() */
102 	uint64_t zap_flags;		/* zap_flag_t */
103 	/*
104 	 * This structure is followed by padding, and then the embedded
105 	 * pointer table.  The embedded pointer table takes up second
106 	 * half of the block.  It is accessed using the
107 	 * ZAP_EMBEDDED_PTRTBL_ENT() macro.
108 	 */
109 } zap_phys_t;
110 
111 #endif /* _SYS_ZAP_IMPL_H */
112