LXR linux/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
  27static 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
  34int 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}
 158