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