1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * fs/partitions/atari.c
4 *
5 * Code extracted from drivers/block/genhd.c
6 *
7 * Copyright (C) 1991-1998 Linus Torvalds
8 * Re-organised Feb 1998 Russell King
9 */
10
11 #include <linux/ctype.h>
12 #include "check.h"
13 #include "atari.h"
14
15 /* ++guenther: this should be settable by the user ("make config")?.
16 */
17 #define ICD_PARTS
18
19 /* check if a partition entry looks valid -- Atari format is assumed if at
20 least one of the primary entries is ok this way */
21 #define VALID_PARTITION(pi,hdsiz) \
22 (((pi)->flg & 1) && \
23 isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
24 be32_to_cpu((pi)->st) <= (hdsiz) && \
25 be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
26
27 static inline int OK_id(char *s)
28 {
29 return memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
30 memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
31 memcmp (s, "RAW", 3) == 0 ;
32 }
33
34 int atari_partition(struct parsed_partitions *state)
35 {
36 Sector sect;
37 struct rootsector *rs;
38 struct partition_info *pi;
39 u32 extensect;
40 u32 hd_size;
41 int slot;
42 #ifdef ICD_PARTS
43 int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
44 #endif
45
46 /*
47 * ATARI partition scheme supports 512 lba only. If this is not
48 * the case, bail early to avoid miscalculating hd_size.
49 */
50 if (bdev_logical_block_size(state->bdev) != 512)
51 return 0;
52
53 rs = read_part_sector(state, 0, §);
54 if (!rs)
55 return -1;
56
57 /* Verify this is an Atari rootsector: */
58 hd_size = state->bdev->bd_inode->i_size >> 9;
59 if (!VALID_PARTITION(&rs->part[0], hd_size) &&
60 !VALID_PARTITION(&rs->part[1], hd_size) &&
61 !VALID_PARTITION(&rs->part[2], hd_size) &&
62 !VALID_PARTITION(&rs->part[3], hd_size)) {
63 /*
64 * if there's no valid primary partition, assume that no Atari
65 * format partition table (there's no reliable magic or the like
66 * :-()
67 */
68 put_dev_sector(sect);
69 return 0;
70 }
71
72 pi = &rs->part[0];
73 strlcat(state->pp_buf, " AHDI", PAGE_SIZE);
74 for (slot = 1; pi < &rs->part[4] && slot < state->limit; slot++, pi++) {
75 struct rootsector *xrs;
76 Sector sect2;
77 ulong partsect;
78
79 if ( !(pi->flg & 1) )
80 continue;
81 /* active partition */
82 if (memcmp (pi->id, "XGM", 3) != 0) {
83 /* we don't care about other id's */
84 put_partition (state, slot, be32_to_cpu(pi->st),
85 be32_to_cpu(pi->siz));
86 continue;
87 }
88 /* extension partition */
89 #ifdef ICD_PARTS
90 part_fmt = 1;
91 #endif
92 strlcat(state->pp_buf, " XGM<", PAGE_SIZE);
93 partsect = extensect = be32_to_cpu(pi->st);
94 while (1) {
95 xrs = read_part_sector(state, partsect, §2);
96 if (!xrs) {
97 printk (" block %ld read failed\n", partsect);
98 put_dev_sector(sect);
99 return -1;
100 }
101
102 /* ++roman: sanity check: bit 0 of flg field must be set */
103 if (!(xrs->part[0].flg & 1)) {
104 printk( "\nFirst sub-partition in extended partition is not valid!\n" );
105 put_dev_sector(sect2);
106 break;
107 }
108
109 put_partition(state, slot,
110 partsect + be32_to_cpu(xrs->part[0].st),
111 be32_to_cpu(xrs->part[0].siz));
112
113 if (!(xrs->part[1].flg & 1)) {
114 /* end of linked partition list */
115 put_dev_sector(sect2);
116 break;
117 }
118 if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
119 printk("\nID of extended partition is not XGM!\n");
120 put_dev_sector(sect2);
121 break;
122 }
123
124 partsect = be32_to_cpu(xrs->part[1].st) + extensect;
125 put_dev_sector(sect2);
126 if (++slot == state->limit) {
127 printk( "\nMaximum number of partitions reached!\n" );
128 break;
129 }
130 }
131 strlcat(state->pp_buf, " >", PAGE_SIZE);
132 }
133 #ifdef ICD_PARTS
134 if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
135 pi = &rs->icdpart[0];
136 /* sanity check: no ICD format if first partition invalid */
137 if (OK_id(pi->id)) {
138 strlcat(state->pp_buf, " ICD<", PAGE_SIZE);
139 for (; pi < &rs->icdpart[8] && slot < state->limit; slot++, pi++) {
140 /* accept only GEM,BGM,RAW,LNX,SWP partitions */
141 if (!((pi->flg & 1) && OK_id(pi->id)))
142 continue;
143 part_fmt = 2;
144 put_partition (state, slot,
145 be32_to_cpu(pi->st),
146 be32_to_cpu(pi->siz));
147 }
148 strlcat(state->pp_buf, " >", PAGE_SIZE);
149 }
150 }
151 #endif
152 put_dev_sector(sect);
153
154 strlcat(state->pp_buf, "\n", PAGE_SIZE);
155
156 return 1;
157 }