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