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
mac_fix_string(char * stg,int len)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
mac_partition(struct parsed_partitions * state)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, §);
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
55 /*
56 * If the "block size" is not a power of 2, things get weird - we might
57 * end up with a partition straddling a sector boundary, so we wouldn't
58 * be able to read a partition entry with read_part_sector().
59 * Real block sizes are probably (?) powers of two, so just require
60 * that.
61 */
62 if (!is_power_of_2(secsize))
63 return -1;
64 datasize = round_down(secsize, 512);
65 data = read_part_sector(state, datasize / 512, §);
66 if (!data)
67 return -1;
68 partoffset = secsize % 512;
69 if (partoffset + sizeof(*part) > datasize) {
70 put_dev_sector(sect);
71 return -1;
72 }
73 part = (struct mac_partition *) (data + partoffset);
74 if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
75 put_dev_sector(sect);
76 return 0; /* not a MacOS disk */
77 }
78 blocks_in_map = be32_to_cpu(part->map_count);
79 if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
80 put_dev_sector(sect);
81 return 0;
82 }
83
84 if (blocks_in_map >= state->limit)
85 blocks_in_map = state->limit - 1;
86
87 strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
88 for (slot = 1; slot <= blocks_in_map; ++slot) {
89 int pos = slot * secsize;
90 put_dev_sector(sect);
91 data = read_part_sector(state, pos/512, §);
92 if (!data)
93 return -1;
94 part = (struct mac_partition *) (data + pos%512);
95 if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
96 break;
97 put_partition(state, slot,
98 be32_to_cpu(part->start_block) * (secsize/512),
99 be32_to_cpu(part->block_count) * (secsize/512));
100
101 if (!strncasecmp(part->type, "Linux_RAID", 10))
102 state->parts[slot].flags = ADDPART_FLAG_RAID;
103 #ifdef CONFIG_PPC_PMAC
104 /*
105 * If this is the first bootable partition, tell the
106 * setup code, in case it wants to make this the root.
107 */
108 if (machine_is(powermac)) {
109 int goodness = 0;
110
111 mac_fix_string(part->processor, 16);
112 mac_fix_string(part->name, 32);
113 mac_fix_string(part->type, 32);
114
115 if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
116 && strcasecmp(part->processor, "powerpc") == 0)
117 goodness++;
118
119 if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
120 || (strncasecmp(part->type, "Linux", 5) == 0
121 && strcasecmp(part->type, "Linux_swap") != 0)) {
122 int i, l;
123
124 goodness++;
125 l = strnlen(part->name, sizeof(part->name));
126 if (strncmp(part->name, "/", sizeof(part->name)) == 0)
127 goodness++;
128 for (i = 0; i <= l - 4; ++i) {
129 if (strncasecmp(part->name + i, "root",
130 4) == 0) {
131 goodness += 2;
132 break;
133 }
134 }
135 if (strncasecmp(part->name, "swap", 4) == 0)
136 goodness--;
137 }
138
139 if (goodness > found_root_goodness) {
140 found_root = slot;
141 found_root_goodness = goodness;
142 }
143 }
144 #endif /* CONFIG_PPC_PMAC */
145 }
146 #ifdef CONFIG_PPC_PMAC
147 if (found_root_goodness)
148 note_bootable_part(state->disk->part0->bd_dev, found_root,
149 found_root_goodness);
150 #endif
151
152 put_dev_sector(sect);
153 strlcat(state->pp_buf, "\n", PAGE_SIZE);
154 return 1;
155 }
156