xref: /kernel/linux/linux-5.10/block/partitions/mac.c (revision 8c2ecf20) 
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>
16extern void note_bootable_part(dev_t dev, int part, int goodness);
17#endif
18
19/*
20 * Code to understand MacOS partition tables.
21 */
22
23static 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
31int 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