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         int start_sect, nr_sects, blk, part, res = 0;
  36         int blksize = 1;        /* Multiplier for disk block size */
  37         int slot = 1;
  38         char b[BDEVNAME_SIZE];
  39
  40         for (blk = 0; ; blk++, put_dev_sector(sect)) {
  41                 if (blk == RDB_ALLOCATION_LIMIT)
  42                         goto rdb_done;
  43                 data = read_part_sector(state, blk, &sect);
  44                 if (!data) {
  45                         pr_err("Dev %s: unable to read RDB block %d\n",
  46                                bdevname(state->bdev, b), blk);
  47                         res = -1;
  48                         goto rdb_done;
  49                 }
  50                 if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
  51                         continue;
  52
  53                 rdb = (struct RigidDiskBlock *)data;
  54                 if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
  55                         break;
  56                 /* Try again with 0xdc..0xdf zeroed, Windows might have
  57                  * trashed it.
  58                  */
  59                 *(__be32 *)(data+0xdc) = 0;
  60                 if (checksum_block((__be32 *)data,
  61                                 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
  62                         pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n",
  63                                blk);
  64                         break;
  65                 }
  66
  67                 pr_err("Dev %s: RDB in block %d has bad checksum\n",
  68                        bdevname(state->bdev, b), blk);
  69         }
  70
  71         /* blksize is blocks per 512 byte standard block */
  72         blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
  73
  74         {
  75                 char tmp[7 + 10 + 1 + 1];
  76
  77                 /* Be more informative */
  78                 snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512);
  79                 strlcat(state->pp_buf, tmp, PAGE_SIZE);
  80         }
  81         blk = be32_to_cpu(rdb->rdb_PartitionList);
  82         put_dev_sector(sect);
  83         for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
  84                 blk *= blksize; /* Read in terms partition table understands */
  85                 data = read_part_sector(state, blk, &sect);
  86                 if (!data) {
  87                         pr_err("Dev %s: unable to read partition block %d\n",
  88                                bdevname(state->bdev, b), blk);
  89                         res = -1;
  90                         goto rdb_done;
  91                 }
  92                 pb  = (struct PartitionBlock *)data;
  93                 blk = be32_to_cpu(pb->pb_Next);
  94                 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
  95                         continue;
  96                 if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
  97                         continue;
  98
  99                 /* Tell Kernel about it */
 100
 101                 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
 102                             be32_to_cpu(pb->pb_Environment[9])) *
 103                            be32_to_cpu(pb->pb_Environment[3]) *
 104                            be32_to_cpu(pb->pb_Environment[5]) *
 105                            blksize;
 106                 if (!nr_sects)
 107                         continue;
 108                 start_sect = be32_to_cpu(pb->pb_Environment[9]) *
 109                              be32_to_cpu(pb->pb_Environment[3]) *
 110                              be32_to_cpu(pb->pb_Environment[5]) *
 111                              blksize;
 112                 put_partition(state,slot++,start_sect,nr_sects);
 113                 {
 114                         /* Be even more informative to aid mounting */
 115                         char dostype[4];
 116                         char tmp[42];
 117
 118                         __be32 *dt = (__be32 *)dostype;
 119                         *dt = pb->pb_Environment[16];
 120                         if (dostype[3] < ' ')
 121                                 snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)",
 122                                         dostype[0], dostype[1],
 123                                         dostype[2], dostype[3] + '@' );
 124                         else
 125                                 snprintf(tmp, sizeof(tmp), " (%c%c%c%c)",
 126                                         dostype[0], dostype[1],
 127                                         dostype[2], dostype[3]);
 128                         strlcat(state->pp_buf, tmp, PAGE_SIZE);
 129                         snprintf(tmp, sizeof(tmp), "(res %d spb %d)",
 130                                 be32_to_cpu(pb->pb_Environment[6]),
 131                                 be32_to_cpu(pb->pb_Environment[4]));
 132                         strlcat(state->pp_buf, tmp, PAGE_SIZE);
 133                 }
 134                 res = 1;
 135         }
 136         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 137
 138 rdb_done:
 139         return res;
 140 }