block/partitions/mac.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  fs/partitions/mac.c
   4  *
   5  *  Code extracted from drivers/block/genhd.c
   6  *  Copyright (C) 1991-1998  Linus Torvalds
   7  *  Re-organised Feb 1998 Russell King
   8  */
   9
  10 #include <linux/ctype.h>
  11 #include "check.h"
  12 #include "mac.h"
  13
  14 #ifdef CONFIG_PPC_PMAC
  15 #include <asm/machdep.h>
  16 extern void note_bootable_part(dev_t dev, int part, int goodness);
  17 #endif
  18
  19 /*
  20  * Code to understand MacOS partition tables.
  21  */
  22
  23 #ifdef CONFIG_PPC_PMAC
  24 static inline void mac_fix_string(char *stg, int len)
  25 {
  26         int i;
  27
  28         for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
  29                 stg[i] = 0;
  30 }
  31 #endif
  32
  33 int mac_partition(struct parsed_partitions *state)
  34 {
  35         Sector sect;
  36         unsigned char *data;
  37         int slot, blocks_in_map;
  38         unsigned secsize, datasize, partoffset;
  39 #ifdef CONFIG_PPC_PMAC
  40         int found_root = 0;
  41         int found_root_goodness = 0;
  42 #endif
  43         struct mac_partition *part;
  44         struct mac_driver_desc *md;
  45
  46         /* Get 0th block and look at the first partition map entry. */
  47         md = read_part_sector(state, 0, &sect);
  48         if (!md)
  49                 return -1;
  50         if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
  51                 put_dev_sector(sect);
  52                 return 0;
  53         }
  54         secsize = be16_to_cpu(md->block_size);
  55         put_dev_sector(sect);
  56         datasize = round_down(secsize, 512);
  57         data = read_part_sector(state, datasize / 512, &sect);
  58         if (!data)
  59                 return -1;
  60         partoffset = secsize % 512;
  61         if (partoffset + sizeof(*part) > datasize)
  62                 return -1;
  63         part = (struct mac_partition *) (data + partoffset);
  64         if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
  65                 put_dev_sector(sect);
  66                 return 0;               /* not a MacOS disk */
  67         }
  68         blocks_in_map = be32_to_cpu(part->map_count);
  69         if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
  70                 put_dev_sector(sect);
  71                 return 0;
  72         }
  73
  74         if (blocks_in_map >= state->limit)
  75                 blocks_in_map = state->limit - 1;
  76
  77         strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
  78         for (slot = 1; slot <= blocks_in_map; ++slot) {
  79                 int pos = slot * secsize;
  80                 put_dev_sector(sect);
  81                 data = read_part_sector(state, pos/512, &sect);
  82                 if (!data)
  83                         return -1;
  84                 part = (struct mac_partition *) (data + pos%512);
  85                 if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
  86                         break;
  87                 put_partition(state, slot,
  88                         be32_to_cpu(part->start_block) * (secsize/512),
  89                         be32_to_cpu(part->block_count) * (secsize/512));
  90
  91                 if (!strncasecmp(part->type, "Linux_RAID", 10))
  92                         state->parts[slot].flags = ADDPART_FLAG_RAID;
  93 #ifdef CONFIG_PPC_PMAC
  94                 /*
  95                  * If this is the first bootable partition, tell the
  96                  * setup code, in case it wants to make this the root.
  97                  */
  98                 if (machine_is(powermac)) {
  99                         int goodness = 0;
 100
 101                         mac_fix_string(part->processor, 16);
 102                         mac_fix_string(part->name, 32);
 103                         mac_fix_string(part->type, 32);
 104
 105                         if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
 106                             && strcasecmp(part->processor, "powerpc") == 0)
 107                                 goodness++;
 108
 109                         if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
 110                             || (strncasecmp(part->type, "Linux", 5) == 0
 111                                 && strcasecmp(part->type, "Linux_swap") != 0)) {
 112                                 int i, l;
 113
 114                                 goodness++;
 115                                 l = strlen(part->name);
 116                                 if (strcmp(part->name, "/") == 0)
 117                                         goodness++;
 118                                 for (i = 0; i <= l - 4; ++i) {
 119                                         if (strncasecmp(part->name + i, "root",
 120                                                      4) == 0) {
 121                                                 goodness += 2;
 122                                                 break;
 123                                         }
 124                                 }
 125                                 if (strncasecmp(part->name, "swap", 4) == 0)
 126                                         goodness--;
 127                         }
 128
 129                         if (goodness > found_root_goodness) {
 130                                 found_root = slot;
 131                                 found_root_goodness = goodness;
 132                         }
 133                 }
 134 #endif /* CONFIG_PPC_PMAC */
 135         }
 136 #ifdef CONFIG_PPC_PMAC
 137         if (found_root_goodness)
 138                 note_bootable_part(state->disk->part0->bd_dev, found_root,
 139                                    found_root_goodness);
 140 #endif
 141
 142         put_dev_sector(sect);
 143         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 144         return 1;
 145 }