GNU Linux-libre 5.19-rc6-gnu
[releases.git] / 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 static inline void mac_fix_string(char *stg, int len)
24 {
25         int i;
26
27         for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
28                 stg[i] = 0;
29 }
30
31 int mac_partition(struct parsed_partitions *state)
32 {
33         Sector sect;
34         unsigned char *data;
35         int slot, blocks_in_map;
36         unsigned secsize, datasize, partoffset;
37 #ifdef CONFIG_PPC_PMAC
38         int found_root = 0;
39         int found_root_goodness = 0;
40 #endif
41         struct mac_partition *part;
42         struct mac_driver_desc *md;
43
44         /* Get 0th block and look at the first partition map entry. */
45         md = read_part_sector(state, 0, &sect);
46         if (!md)
47                 return -1;
48         if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
49                 put_dev_sector(sect);
50                 return 0;
51         }
52         secsize = be16_to_cpu(md->block_size);
53         put_dev_sector(sect);
54         datasize = round_down(secsize, 512);
55         data = read_part_sector(state, datasize / 512, &sect);
56         if (!data)
57                 return -1;
58         partoffset = secsize % 512;
59         if (partoffset + sizeof(*part) > datasize)
60                 return -1;
61         part = (struct mac_partition *) (data + partoffset);
62         if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
63                 put_dev_sector(sect);
64                 return 0;               /* not a MacOS disk */
65         }
66         blocks_in_map = be32_to_cpu(part->map_count);
67         if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
68                 put_dev_sector(sect);
69                 return 0;
70         }
71
72         if (blocks_in_map >= state->limit)
73                 blocks_in_map = state->limit - 1;
74
75         strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
76         for (slot = 1; slot <= blocks_in_map; ++slot) {
77                 int pos = slot * secsize;
78                 put_dev_sector(sect);
79                 data = read_part_sector(state, pos/512, &sect);
80                 if (!data)
81                         return -1;
82                 part = (struct mac_partition *) (data + pos%512);
83                 if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
84                         break;
85                 put_partition(state, slot,
86                         be32_to_cpu(part->start_block) * (secsize/512),
87                         be32_to_cpu(part->block_count) * (secsize/512));
88
89                 if (!strncasecmp(part->type, "Linux_RAID", 10))
90                         state->parts[slot].flags = ADDPART_FLAG_RAID;
91 #ifdef CONFIG_PPC_PMAC
92                 /*
93                  * If this is the first bootable partition, tell the
94                  * setup code, in case it wants to make this the root.
95                  */
96                 if (machine_is(powermac)) {
97                         int goodness = 0;
98
99                         mac_fix_string(part->processor, 16);
100                         mac_fix_string(part->name, 32);
101                         mac_fix_string(part->type, 32);                                 
102                     
103                         if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
104                             && strcasecmp(part->processor, "powerpc") == 0)
105                                 goodness++;
106
107                         if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
108                             || (strncasecmp(part->type, "Linux", 5) == 0
109                                 && strcasecmp(part->type, "Linux_swap") != 0)) {
110                                 int i, l;
111
112                                 goodness++;
113                                 l = strlen(part->name);
114                                 if (strcmp(part->name, "/") == 0)
115                                         goodness++;
116                                 for (i = 0; i <= l - 4; ++i) {
117                                         if (strncasecmp(part->name + i, "root",
118                                                      4) == 0) {
119                                                 goodness += 2;
120                                                 break;
121                                         }
122                                 }
123                                 if (strncasecmp(part->name, "swap", 4) == 0)
124                                         goodness--;
125                         }
126
127                         if (goodness > found_root_goodness) {
128                                 found_root = slot;
129                                 found_root_goodness = goodness;
130                         }
131                 }
132 #endif /* CONFIG_PPC_PMAC */
133         }
134 #ifdef CONFIG_PPC_PMAC
135         if (found_root_goodness)
136                 note_bootable_part(state->disk->part0->bd_dev, found_root,
137                                    found_root_goodness);
138 #endif
139
140         put_dev_sector(sect);
141         strlcat(state->pp_buf, "\n", PAGE_SIZE);
142         return 1;
143 }