LXR linux/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
  18static __inline__ u32
  19checksum_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
  28int 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
 137rdb_done:
 138        return res;
 139}
 140