fs/partitions/amiga.c

   1 /*
   2  *  fs/partitions/amiga.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  *
   6  *  Copyright (C) 1991-1998  Linus Torvalds
   7  *  Re-organised Feb 1998 Russell King
   8  */
   9
  10 #include <linux/fs.h>
  11 #include <linux/genhd.h>
  12 #include <linux/kernel.h>
  13 #include <linux/major.h>
  14 #include <linux/string.h>
  15 #include <linux/blk.h>
  16
  17 #include <asm/byteorder.h>
  18 #include <linux/affs_hardblocks.h>
  19
  20 #include "check.h"
  21 #include "amiga.h"
  22
  23 static __inline__ u32
  24 checksum_block(u32 *m, int size)
  25 {
  26         u32 sum = 0;
  27
  28         while (size--)
  29                 sum += be32_to_cpu(*m++);
  30         return sum;
  31 }
  32
  33 int
  34 amiga_partition(struct gendisk *hd, struct block_device *bdev,
  35                 unsigned long first_sector, int first_part_minor)
  36 {
  37         Sector sect;
  38         unsigned char *data;
  39         struct RigidDiskBlock *rdb;
  40         struct PartitionBlock *pb;
  41         int start_sect, nr_sects, blk, part, res = 0;
  42         kdev_t dev = to_kdev_t(bdev->bd_dev);
  43
  44         for (blk = 0; ; blk++, put_dev_sector(sect)) {
  45                 if (blk == RDB_ALLOCATION_LIMIT)
  46                         goto rdb_done;
  47                 data = read_dev_sector(bdev, blk, &sect);
  48                 if (!data) {
  49                         if (warn_no_part)
  50                                 printk("Dev %s: unable to read RDB block %d\n",
  51                                        bdevname(dev), blk);
  52                         goto rdb_done;
  53                 }
  54                 if (*(u32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
  55                         continue;
  56
  57                 rdb = (struct RigidDiskBlock *)data;
  58                 if (checksum_block((u32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
  59                         break;
  60                 /* Try again with 0xdc..0xdf zeroed, Windows might have
  61                  * trashed it.
  62                  */
  63                 *(u32 *)(data+0xdc) = 0;
  64                 if (checksum_block((u32 *)data,
  65                                 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
  66                         printk("Warning: Trashed word at 0xd0 in block %d "
  67                                 "ignored in checksum calculation\n",blk);
  68                         break;
  69                 }
  70
  71                 printk("Dev %s: RDB in block %d has bad checksum\n",
  72                                bdevname(dev),blk);
  73         }
  74
  75         printk(" RDSK");
  76         blk = be32_to_cpu(rdb->rdb_PartitionList);
  77         put_dev_sector(sect);
  78         for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
  79                 data = read_dev_sector(bdev, blk, &sect);
  80                 if (!data) {
  81                         if (warn_no_part)
  82                                 printk("Dev %s: unable to read partition block %d\n",
  83                                        bdevname(dev),blk);
  84                         goto rdb_done;
  85                 }
  86                 pb  = (struct PartitionBlock *)data;
  87                 blk = be32_to_cpu(pb->pb_Next);
  88                 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
  89                         continue;
  90                 if (checksum_block((u32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
  91                         continue;
  92
  93                 /* Tell Kernel about it */
  94
  95                 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
  96                             be32_to_cpu(pb->pb_Environment[9])) *
  97                            be32_to_cpu(pb->pb_Environment[3]) *
  98                            be32_to_cpu(pb->pb_Environment[5]);
  99                 if (!nr_sects)
 100                         continue;
 101                 start_sect = be32_to_cpu(pb->pb_Environment[9]) *
 102                              be32_to_cpu(pb->pb_Environment[3]) *
 103                              be32_to_cpu(pb->pb_Environment[5]);
 104                 add_gd_partition(hd,first_part_minor,start_sect,nr_sects);
 105                 first_part_minor++;
 106                 res = 1;
 107         }
 108         printk("\n");
 109
 110 rdb_done:
 111         return res;
 112 }