GNU Linux-libre 5.19-rc6-gnu
[releases.git] / block / partitions / amiga.c
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
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
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, &sect);
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, &sect);
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 }