1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * fs/partitions/amiga.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 #define pr_fmt(fmt) fmt
12
13 #include <linux/types.h>
14 #include <linux/affs_hardblocks.h>
15
16 #include "check.h"
17 #include "amiga.h"
18
19 static __inline__ u32
checksum_block(__be32 * m,int size)20 checksum_block(__be32 *m, int size)
21 {
22 u32 sum = 0;
23
24 while (size--)
25 sum += be32_to_cpu(*m++);
26 return sum;
27 }
28
amiga_partition(struct parsed_partitions * state)29 int amiga_partition(struct parsed_partitions *state)
30 {
31 Sector sect;
32 unsigned char *data;
33 struct RigidDiskBlock *rdb;
34 struct PartitionBlock *pb;
35 sector_t start_sect, nr_sects;
36 int blk, part, res = 0;
37 int blksize = 1; /* Multiplier for disk block size */
38 int slot = 1;
39 char b[BDEVNAME_SIZE];
40
41 for (blk = 0; ; blk++, put_dev_sector(sect)) {
42 if (blk == RDB_ALLOCATION_LIMIT)
43 goto rdb_done;
44 data = read_part_sector(state, blk, §);
45 if (!data) {
46 if (warn_no_part)
47 pr_err("Dev %s: unable to read RDB block %d\n",
48 bdevname(state->bdev, b), blk);
49 res = -1;
50 goto rdb_done;
51 }
52 if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
53 continue;
54
55 rdb = (struct RigidDiskBlock *)data;
56 if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
57 break;
58 /* Try again with 0xdc..0xdf zeroed, Windows might have
59 * trashed it.
60 */
61 *(__be32 *)(data+0xdc) = 0;
62 if (checksum_block((__be32 *)data,
63 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
64 pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n",
65 blk);
66 break;
67 }
68
69 pr_err("Dev %s: RDB in block %d has bad checksum\n",
70 bdevname(state->bdev, b), blk);
71 }
72
73 /* blksize is blocks per 512 byte standard block */
74 blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
75
76 {
77 char tmp[7 + 10 + 1 + 1];
78
79 /* Be more informative */
80 snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512);
81 strlcat(state->pp_buf, tmp, PAGE_SIZE);
82 }
83 blk = be32_to_cpu(rdb->rdb_PartitionList);
84 put_dev_sector(sect);
85 for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
86 blk *= blksize; /* Read in terms partition table understands */
87 data = read_part_sector(state, blk, §);
88 if (!data) {
89 if (warn_no_part)
90 pr_err("Dev %s: unable to read partition block %d\n",
91 bdevname(state->bdev, b), blk);
92 res = -1;
93 goto rdb_done;
94 }
95 pb = (struct PartitionBlock *)data;
96 blk = be32_to_cpu(pb->pb_Next);
97 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
98 continue;
99 if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
100 continue;
101
102 /* Tell Kernel about it */
103
104 nr_sects = ((sector_t)be32_to_cpu(pb->pb_Environment[10]) + 1 -
105 be32_to_cpu(pb->pb_Environment[9])) *
106 be32_to_cpu(pb->pb_Environment[3]) *
107 be32_to_cpu(pb->pb_Environment[5]) *
108 blksize;
109 if (!nr_sects)
110 continue;
111 start_sect = (sector_t)be32_to_cpu(pb->pb_Environment[9]) *
112 be32_to_cpu(pb->pb_Environment[3]) *
113 be32_to_cpu(pb->pb_Environment[5]) *
114 blksize;
115 put_partition(state,slot++,start_sect,nr_sects);
116 {
117 /* Be even more informative to aid mounting */
118 char dostype[4];
119 char tmp[42];
120
121 __be32 *dt = (__be32 *)dostype;
122 *dt = pb->pb_Environment[16];
123 if (dostype[3] < ' ')
124 snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)",
125 dostype[0], dostype[1],
126 dostype[2], dostype[3] + '@' );
127 else
128 snprintf(tmp, sizeof(tmp), " (%c%c%c%c)",
129 dostype[0], dostype[1],
130 dostype[2], dostype[3]);
131 strlcat(state->pp_buf, tmp, PAGE_SIZE);
132 snprintf(tmp, sizeof(tmp), "(res %d spb %d)",
133 be32_to_cpu(pb->pb_Environment[6]),
134 be32_to_cpu(pb->pb_Environment[4]));
135 strlcat(state->pp_buf, tmp, PAGE_SIZE);
136 }
137 res = 1;
138 }
139 strlcat(state->pp_buf, "\n", PAGE_SIZE);
140
141 rdb_done:
142 return res;
143 }
144