i386/linux-2.3.21/fs/partitions/atari.c

   1 /*
   2  *  fs/partitions/atari.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 #include <linux/ctype.h>
  17
  18 #include <asm/byteorder.h>
  19 #include <asm/system.h>
  20
  21 #include "check.h"
  22 #include "atari.h"
  23
  24 /* ++guenther: this should be settable by the user ("make config")?.
  25  */
  26 #define ICD_PARTS
  27
  28 /* check if a partition entry looks valid -- Atari format is assumed if at
  29    least one of the primary entries is ok this way */
  30 #define VALID_PARTITION(pi,hdsiz)                                            \
  31     (((pi)->flg & 1) &&                                                      \
  32      isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
  33      be32_to_cpu((pi)->st) <= (hdsiz) &&                                     \
  34      be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
  35
  36 int atari_partition (struct gendisk *hd, kdev_t dev,
  37                      unsigned long first_sector, int first_part_minor)
  38 {
  39   int minor = first_part_minor, m_lim = first_part_minor + hd->max_p;
  40   struct buffer_head *bh;
  41   struct rootsector *rs;
  42   struct partition_info *pi;
  43   u32 extensect;
  44   u32 hd_size;
  45 #ifdef ICD_PARTS
  46   int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
  47 #endif
  48
  49   bh = bread (dev, 0, get_ptable_blocksize(dev));
  50   if (!bh) {
  51       printk (" unable to read block 0 (partition table)\n");
  52       return -1;
  53   }
  54
  55   /* Verify this is an Atari rootsector: */
  56   rs = (struct rootsector *) bh->b_data;
  57   hd_size = hd->part[minor - 1].nr_sects;
  58   if (!VALID_PARTITION(&rs->part[0], hd_size) &&
  59       !VALID_PARTITION(&rs->part[1], hd_size) &&
  60       !VALID_PARTITION(&rs->part[2], hd_size) &&
  61       !VALID_PARTITION(&rs->part[3], hd_size)) {
  62       /* if there's no valid primary partition, assume that no Atari
  63          format partition table (there's no reliable magic or the like
  64          :-() */
  65       return 0;
  66   }
  67
  68   pi = &rs->part[0];
  69   printk (" AHDI");
  70   for (; pi < &rs->part[4] && minor < m_lim; minor++, pi++)
  71     {
  72       if (pi->flg & 1)
  73         /* active partition */
  74         {
  75           if (memcmp (pi->id, "XGM", 3) == 0)
  76             /* extension partition */
  77             {
  78               struct rootsector *xrs;
  79               struct buffer_head *xbh;
  80               ulong partsect;
  81
  82 #ifdef ICD_PARTS
  83               part_fmt = 1;
  84 #endif
  85               printk(" XGM<");
  86               partsect = extensect = be32_to_cpu(pi->st);
  87               while (1)
  88                 {
  89                   xbh = bread (dev, partsect / 2, get_ptable_blocksize(dev));
  90                   if (!xbh)
  91                     {
  92                       printk (" block %ld read failed\n", partsect);
  93                       brelse(bh);
  94                       return 0;
  95                     }
  96                   if (partsect & 1)
  97                     xrs = (struct rootsector *) &xbh->b_data[512];
  98                   else
  99                     xrs = (struct rootsector *) &xbh->b_data[0];
 100
 101                   /* ++roman: sanity check: bit 0 of flg field must be set */
 102                   if (!(xrs->part[0].flg & 1)) {
 103                     printk( "\nFirst sub-partition in extended partition is not valid!\n" );
 104                     break;
 105                   }
 106
 107                   add_gd_partition(hd, minor,
 108                                    partsect + be32_to_cpu(xrs->part[0].st),
 109                                    be32_to_cpu(xrs->part[0].siz));
 110
 111                   if (!(xrs->part[1].flg & 1)) {
 112                     /* end of linked partition list */
 113                     brelse( xbh );
 114                     break;
 115                   }
 116                   if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
 117                     printk( "\nID of extended partition is not XGM!\n" );
 118                     brelse( xbh );
 119                     break;
 120                   }
 121
 122                   partsect = be32_to_cpu(xrs->part[1].st) + extensect;
 123                   brelse (xbh);
 124                   minor++;
 125                   if (minor >= m_lim) {
 126                     printk( "\nMaximum number of partitions reached!\n" );
 127                     break;
 128                   }
 129                 }
 130               printk(" >");
 131             }
 132           else
 133             {
 134               /* we don't care about other id's */
 135               add_gd_partition (hd, minor, be32_to_cpu(pi->st),
 136                                 be32_to_cpu(pi->siz));
 137             }
 138         }
 139     }
 140 #ifdef ICD_PARTS
 141   if ( part_fmt!=1 ) /* no extended partitions -> test ICD-format */
 142   {
 143     pi = &rs->icdpart[0];
 144     /* sanity check: no ICD format if first partition invalid */
 145     if (memcmp (pi->id, "GEM", 3) == 0 ||
 146         memcmp (pi->id, "BGM", 3) == 0 ||
 147         memcmp (pi->id, "LNX", 3) == 0 ||
 148         memcmp (pi->id, "SWP", 3) == 0 ||
 149         memcmp (pi->id, "RAW", 3) == 0 )
 150     {
 151       printk(" ICD<");
 152       for (; pi < &rs->icdpart[8] && minor < m_lim; minor++, pi++)
 153       {
 154         /* accept only GEM,BGM,RAW,LNX,SWP partitions */
 155         if (pi->flg & 1 &&
 156             (memcmp (pi->id, "GEM", 3) == 0 ||
 157              memcmp (pi->id, "BGM", 3) == 0 ||
 158              memcmp (pi->id, "LNX", 3) == 0 ||
 159              memcmp (pi->id, "SWP", 3) == 0 ||
 160              memcmp (pi->id, "RAW", 3) == 0) )
 161         {
 162           part_fmt = 2;
 163           add_gd_partition (hd, minor, be32_to_cpu(pi->st),
 164                             be32_to_cpu(pi->siz));
 165         }
 166       }
 167       printk(" >");
 168     }
 169   }
 170 #endif
 171   brelse (bh);
 172
 173   printk ("\n");
 174
 175   return 1;
 176 }
 177