block/partitions/atari.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  fs/partitions/atari.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 #include <linux/ctype.h>
  12 #include "check.h"
  13 #include "atari.h"
  14
  15 /* ++guenther: this should be settable by the user ("make config")?.
  16  */
  17 #define ICD_PARTS
  18
  19 /* check if a partition entry looks valid -- Atari format is assumed if at
  20    least one of the primary entries is ok this way */
  21 #define VALID_PARTITION(pi,hdsiz)                                            \
  22     (((pi)->flg & 1) &&                                                      \
  23      isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
  24      be32_to_cpu((pi)->st) <= (hdsiz) &&                                     \
  25      be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
  26
  27 static inline int OK_id(char *s)
  28 {
  29         return  memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
  30                 memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
  31                 memcmp (s, "RAW", 3) == 0 ;
  32 }
  33
  34 int atari_partition(struct parsed_partitions *state)
  35 {
  36         Sector sect;
  37         struct rootsector *rs;
  38         struct partition_info *pi;
  39         u32 extensect;
  40         u32 hd_size;
  41         int slot;
  42 #ifdef ICD_PARTS
  43         int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
  44 #endif
  45
  46         /*
  47          * ATARI partition scheme supports 512 lba only.  If this is not
  48          * the case, bail early to avoid miscalculating hd_size.
  49          */
  50         if (bdev_logical_block_size(state->bdev) != 512)
  51                 return 0;
  52
  53         rs = read_part_sector(state, 0, &sect);
  54         if (!rs)
  55                 return -1;
  56
  57         /* Verify this is an Atari rootsector: */
  58         hd_size = state->bdev->bd_inode->i_size >> 9;
  59         if (!VALID_PARTITION(&rs->part[0], hd_size) &&
  60             !VALID_PARTITION(&rs->part[1], hd_size) &&
  61             !VALID_PARTITION(&rs->part[2], hd_size) &&
  62             !VALID_PARTITION(&rs->part[3], hd_size)) {
  63                 /*
  64                  * if there's no valid primary partition, assume that no Atari
  65                  * format partition table (there's no reliable magic or the like
  66                  * :-()
  67                  */
  68                 put_dev_sector(sect);
  69                 return 0;
  70         }
  71
  72         pi = &rs->part[0];
  73         strlcat(state->pp_buf, " AHDI", PAGE_SIZE);
  74         for (slot = 1; pi < &rs->part[4] && slot < state->limit; slot++, pi++) {
  75                 struct rootsector *xrs;
  76                 Sector sect2;
  77                 ulong partsect;
  78
  79                 if ( !(pi->flg & 1) )
  80                         continue;
  81                 /* active partition */
  82                 if (memcmp (pi->id, "XGM", 3) != 0) {
  83                         /* we don't care about other id's */
  84                         put_partition (state, slot, be32_to_cpu(pi->st),
  85                                         be32_to_cpu(pi->siz));
  86                         continue;
  87                 }
  88                 /* extension partition */
  89 #ifdef ICD_PARTS
  90                 part_fmt = 1;
  91 #endif
  92                 strlcat(state->pp_buf, " XGM<", PAGE_SIZE);
  93                 partsect = extensect = be32_to_cpu(pi->st);
  94                 while (1) {
  95                         xrs = read_part_sector(state, partsect, &sect2);
  96                         if (!xrs) {
  97                                 printk (" block %ld read failed\n", partsect);
  98                                 put_dev_sector(sect);
  99                                 return -1;
 100                         }
 101
 102                         /* ++roman: sanity check: bit 0 of flg field must be set */
 103                         if (!(xrs->part[0].flg & 1)) {
 104                                 printk( "\nFirst sub-partition in extended partition is not valid!\n" );
 105                                 put_dev_sector(sect2);
 106                                 break;
 107                         }
 108
 109                         put_partition(state, slot,
 110                                    partsect + be32_to_cpu(xrs->part[0].st),
 111                                    be32_to_cpu(xrs->part[0].siz));
 112
 113                         if (!(xrs->part[1].flg & 1)) {
 114                                 /* end of linked partition list */
 115                                 put_dev_sector(sect2);
 116                                 break;
 117                         }
 118                         if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
 119                                 printk("\nID of extended partition is not XGM!\n");
 120                                 put_dev_sector(sect2);
 121                                 break;
 122                         }
 123
 124                         partsect = be32_to_cpu(xrs->part[1].st) + extensect;
 125                         put_dev_sector(sect2);
 126                         if (++slot == state->limit) {
 127                                 printk( "\nMaximum number of partitions reached!\n" );
 128                                 break;
 129                         }
 130                 }
 131                 strlcat(state->pp_buf, " >", PAGE_SIZE);
 132         }
 133 #ifdef ICD_PARTS
 134         if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
 135                 pi = &rs->icdpart[0];
 136                 /* sanity check: no ICD format if first partition invalid */
 137                 if (OK_id(pi->id)) {
 138                         strlcat(state->pp_buf, " ICD<", PAGE_SIZE);
 139                         for (; pi < &rs->icdpart[8] && slot < state->limit; slot++, pi++) {
 140                                 /* accept only GEM,BGM,RAW,LNX,SWP partitions */
 141                                 if (!((pi->flg & 1) && OK_id(pi->id)))
 142                                         continue;
 143                                 part_fmt = 2;
 144                                 put_partition (state, slot,
 145                                                 be32_to_cpu(pi->st),
 146                                                 be32_to_cpu(pi->siz));
 147                         }
 148                         strlcat(state->pp_buf, " >", PAGE_SIZE);
 149                 }
 150         }
 151 #endif
 152         put_dev_sector(sect);
 153
 154         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 155
 156         return 1;
 157 }