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1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  *  GRUB  --  GRand Unified Bootloader
4  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
5  */
6 /*
7  * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
8  */
9 
10 #ifndef	_SYS_ZAP_IMPL_H
11 #define	_SYS_ZAP_IMPL_H
12 
13 #define	ZAP_MAGIC 0x2F52AB2ABULL
14 
15 #define	ZAP_HASHBITS		28
16 #define	MZAP_ENT_LEN		64
17 #define	MZAP_NAME_LEN		(MZAP_ENT_LEN - 8 - 4 - 2)
18 #define	MZAP_MAX_BLKSHIFT	SPA_MAXBLOCKSHIFT
19 #define	MZAP_MAX_BLKSZ		(1 << MZAP_MAX_BLKSHIFT)
20 
21 typedef struct mzap_ent_phys {
22 	uint64_t mze_value;
23 	uint32_t mze_cd;
24 	uint16_t mze_pad;	/* in case we want to chain them someday */
25 	char mze_name[MZAP_NAME_LEN];
26 } mzap_ent_phys_t;
27 
28 typedef struct mzap_phys {
29 	uint64_t mz_block_type;	/* ZBT_MICRO */
30 	uint64_t mz_salt;
31 	uint64_t mz_pad[6];
32 	mzap_ent_phys_t mz_chunk[1];
33 	/* actually variable size depending on block size */
34 } mzap_phys_t;
35 
36 /*
37  * The (fat) zap is stored in one object. It is an array of
38  * 1<<FZAP_BLOCK_SHIFT byte blocks. The layout looks like one of:
39  *
40  * ptrtbl fits in first block:
41  *	[zap_phys_t zap_ptrtbl_shift < 6] [zap_leaf_t] ...
42  *
43  * ptrtbl too big for first block:
44  *	[zap_phys_t zap_ptrtbl_shift >= 6] [zap_leaf_t] [ptrtbl] ...
45  *
46  */
47 
48 #define	ZBT_LEAF		((1ULL << 63) + 0)
49 #define	ZBT_HEADER		((1ULL << 63) + 1)
50 #define	ZBT_MICRO		((1ULL << 63) + 3)
51 /* any other values are ptrtbl blocks */
52 
53 /*
54  * the embedded pointer table takes up half a block:
55  * block size / entry size (2^3) / 2
56  */
57 #define	ZAP_EMBEDDED_PTRTBL_SHIFT(zap) (FZAP_BLOCK_SHIFT(zap) - 3 - 1)
58 
59 /*
60  * The embedded pointer table starts half-way through the block.  Since
61  * the pointer table itself is half the block, it starts at (64-bit)
62  * word number (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)).
63  */
64 #define	ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) \
65 	((uint64_t *)(zap)->zap_f.zap_phys) \
66 	[(idx) + (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap))]
67 
68 /*
69  * TAKE NOTE:
70  * If zap_phys_t is modified, zap_byteswap() must be modified.
71  */
72 typedef struct zap_phys {
73 	uint64_t zap_block_type;	/* ZBT_HEADER */
74 	uint64_t zap_magic;		/* ZAP_MAGIC */
75 
76 	struct zap_table_phys {
77 		uint64_t zt_blk;	/* starting block number */
78 		uint64_t zt_numblks;	/* number of blocks */
79 		uint64_t zt_shift;	/* bits to index it */
80 		uint64_t zt_nextblk;	/* next (larger) copy start block */
81 		uint64_t zt_blks_copied; /* number source blocks copied */
82 	} zap_ptrtbl;
83 
84 	uint64_t zap_freeblk;		/* the next free block */
85 	uint64_t zap_num_leafs;		/* number of leafs */
86 	uint64_t zap_num_entries;	/* number of entries */
87 	uint64_t zap_salt;		/* salt to stir into hash function */
88 	uint64_t zap_normflags;		/* flags for u8_textprep_str() */
89 	uint64_t zap_flags;		/* zap_flag_t */
90 	/*
91 	 * This structure is followed by padding, and then the embedded
92 	 * pointer table.  The embedded pointer table takes up second
93 	 * half of the block.  It is accessed using the
94 	 * ZAP_EMBEDDED_PTRTBL_ENT() macro.
95 	 */
96 } zap_phys_t;
97 
98 #endif /* _SYS_ZAP_IMPL_H */
99