block/partitions/amiga.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *  fs/partitions/amiga.c
0004  *
0005  *  Code extracted from drivers/block/genhd.c
0006  *
0007  *  Copyright (C) 1991-1998  Linus Torvalds
0008  *  Re-organised Feb 1998 Russell King
0009  */
0010
0011 #define pr_fmt(fmt) fmt
0012
0013 #include <linux/types.h>
0014 #include <linux/affs_hardblocks.h>
0015
0016 #include "check.h"
0017
0018 static __inline__ u32
0019 checksum_block(__be32 *m, int size)
0020 {
0021     u32 sum = 0;
0022
0023     while (size--)
0024         sum += be32_to_cpu(*m++);
0025     return sum;
0026 }
0027
0028 int amiga_partition(struct parsed_partitions *state)
0029 {
0030     Sector sect;
0031     unsigned char *data;
0032     struct RigidDiskBlock *rdb;
0033     struct PartitionBlock *pb;
0034     int start_sect, nr_sects, blk, part, res = 0;
0035     int blksize = 1;    /* Multiplier for disk block size */
0036     int slot = 1;
0037
0038     for (blk = 0; ; blk++, put_dev_sector(sect)) {
0039         if (blk == RDB_ALLOCATION_LIMIT)
0040             goto rdb_done;
0041         data = read_part_sector(state, blk, &sect);
0042         if (!data) {
0043             pr_err("Dev %s: unable to read RDB block %d\n",
0044                    state->disk->disk_name, blk);
0045             res = -1;
0046             goto rdb_done;
0047         }
0048         if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
0049             continue;
0050
0051         rdb = (struct RigidDiskBlock *)data;
0052         if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
0053             break;
0054         /* Try again with 0xdc..0xdf zeroed, Windows might have
0055          * trashed it.
0056          */
0057         *(__be32 *)(data+0xdc) = 0;
0058         if (checksum_block((__be32 *)data,
0059                 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
0060             pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n",
0061                    blk);
0062             break;
0063         }
0064
0065         pr_err("Dev %s: RDB in block %d has bad checksum\n",
0066                state->disk->disk_name, blk);
0067     }
0068
0069     /* blksize is blocks per 512 byte standard block */
0070     blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
0071
0072     {
0073         char tmp[7 + 10 + 1 + 1];
0074
0075         /* Be more informative */
0076         snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512);
0077         strlcat(state->pp_buf, tmp, PAGE_SIZE);
0078     }
0079     blk = be32_to_cpu(rdb->rdb_PartitionList);
0080     put_dev_sector(sect);
0081     for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
0082         blk *= blksize; /* Read in terms partition table understands */
0083         data = read_part_sector(state, blk, &sect);
0084         if (!data) {
0085             pr_err("Dev %s: unable to read partition block %d\n",
0086                    state->disk->disk_name, blk);
0087             res = -1;
0088             goto rdb_done;
0089         }
0090         pb  = (struct PartitionBlock *)data;
0091         blk = be32_to_cpu(pb->pb_Next);
0092         if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
0093             continue;
0094         if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
0095             continue;
0096
0097         /* Tell Kernel about it */
0098
0099         nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
0100                 be32_to_cpu(pb->pb_Environment[9])) *
0101                be32_to_cpu(pb->pb_Environment[3]) *
0102                be32_to_cpu(pb->pb_Environment[5]) *
0103                blksize;
0104         if (!nr_sects)
0105             continue;
0106         start_sect = be32_to_cpu(pb->pb_Environment[9]) *
0107                  be32_to_cpu(pb->pb_Environment[3]) *
0108                  be32_to_cpu(pb->pb_Environment[5]) *
0109                  blksize;
0110         put_partition(state,slot++,start_sect,nr_sects);
0111         {
0112             /* Be even more informative to aid mounting */
0113             char dostype[4];
0114             char tmp[42];
0115
0116             __be32 *dt = (__be32 *)dostype;
0117             *dt = pb->pb_Environment[16];
0118             if (dostype[3] < ' ')
0119                 snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)",
0120                     dostype[0], dostype[1],
0121                     dostype[2], dostype[3] + '@' );
0122             else
0123                 snprintf(tmp, sizeof(tmp), " (%c%c%c%c)",
0124                     dostype[0], dostype[1],
0125                     dostype[2], dostype[3]);
0126             strlcat(state->pp_buf, tmp, PAGE_SIZE);
0127             snprintf(tmp, sizeof(tmp), "(res %d spb %d)",
0128                 be32_to_cpu(pb->pb_Environment[6]),
0129                 be32_to_cpu(pb->pb_Environment[4]));
0130             strlcat(state->pp_buf, tmp, PAGE_SIZE);
0131         }
0132         res = 1;
0133     }
0134     strlcat(state->pp_buf, "\n", PAGE_SIZE);
0135
0136 rdb_done:
0137     return res;
0138 }