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
21typedef 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
28typedef 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 */
72typedef 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