xref: /openbmc/linux/block/partitions/mac.c (revision e15a5365)
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->bdev->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 }
144