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 #include "amiga.h"
  18
  19 static __inline__ u32
  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
  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, &sect);
  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, &sect);
  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 }