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 }