LXR linux-old/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
  23static __inline__ u32
  24checksum_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
  33int
  34amiga_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
 110rdb_done:
 111        return res;
 112}
 113