xref: /openbmc/linux/block/partitions/sun.c (revision f9a82c48)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  fs/partitions/sun.c
4  *
5  *  Code extracted from drivers/block/genhd.c
6  *
7  *  Copyright (C) 1991-1998  Linus Torvalds
8  *  Re-organised Feb 1998 Russell King
9  */
10 
11 #include "check.h"
12 #include "sun.h"
13 
14 int sun_partition(struct parsed_partitions *state)
15 {
16 	int i;
17 	__be16 csum;
18 	int slot = 1;
19 	__be16 *ush;
20 	Sector sect;
21 	struct sun_disklabel {
22 		unsigned char info[128];   /* Informative text string */
23 		struct sun_vtoc {
24 		    __be32 version;     /* Layout version */
25 		    char   volume[8];   /* Volume name */
26 		    __be16 nparts;      /* Number of partitions */
27 		    struct sun_info {           /* Partition hdrs, sec 2 */
28 			__be16 id;
29 			__be16 flags;
30 		    } infos[8];
31 		    __be16 padding;     /* Alignment padding */
32 		    __be32 bootinfo[3];  /* Info needed by mboot */
33 		    __be32 sanity;       /* To verify vtoc sanity */
34 		    __be32 reserved[10]; /* Free space */
35 		    __be32 timestamp[8]; /* Partition timestamp */
36 		} vtoc;
37 		__be32 write_reinstruct; /* sectors to skip, writes */
38 		__be32 read_reinstruct;  /* sectors to skip, reads */
39 		unsigned char spare[148]; /* Padding */
40 		__be16 rspeed;     /* Disk rotational speed */
41 		__be16 pcylcount;  /* Physical cylinder count */
42 		__be16 sparecyl;   /* extra sects per cylinder */
43 		__be16 obs1;       /* gap1 */
44 		__be16 obs2;       /* gap2 */
45 		__be16 ilfact;     /* Interleave factor */
46 		__be16 ncyl;       /* Data cylinder count */
47 		__be16 nacyl;      /* Alt. cylinder count */
48 		__be16 ntrks;      /* Tracks per cylinder */
49 		__be16 nsect;      /* Sectors per track */
50 		__be16 obs3;       /* bhead - Label head offset */
51 		__be16 obs4;       /* ppart - Physical Partition */
52 		struct sun_partition {
53 			__be32 start_cylinder;
54 			__be32 num_sectors;
55 		} partitions[8];
56 		__be16 magic;      /* Magic number */
57 		__be16 csum;       /* Label xor'd checksum */
58 	} * label;
59 	struct sun_partition *p;
60 	unsigned long spc;
61 	char b[BDEVNAME_SIZE];
62 	int use_vtoc;
63 	int nparts;
64 
65 	label = read_part_sector(state, 0, &sect);
66 	if (!label)
67 		return -1;
68 
69 	p = label->partitions;
70 	if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
71 /*		printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
72 		       bdevname(bdev, b), be16_to_cpu(label->magic)); */
73 		put_dev_sector(sect);
74 		return 0;
75 	}
76 	/* Look at the checksum */
77 	ush = ((__be16 *) (label+1)) - 1;
78 	for (csum = 0; ush >= ((__be16 *) label);)
79 		csum ^= *ush--;
80 	if (csum) {
81 		printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
82 		       bdevname(state->bdev, b));
83 		put_dev_sector(sect);
84 		return 0;
85 	}
86 
87 	/* Check to see if we can use the VTOC table */
88 	use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
89 		    (be32_to_cpu(label->vtoc.version) == 1) &&
90 		    (be16_to_cpu(label->vtoc.nparts) <= 8));
91 
92 	/* Use 8 partition entries if not specified in validated VTOC */
93 	nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
94 
95 	/*
96 	 * So that old Linux-Sun partitions continue to work,
97 	 * alow the VTOC to be used under the additional condition ...
98 	 */
99 	use_vtoc = use_vtoc || !(label->vtoc.sanity ||
100 				 label->vtoc.version || label->vtoc.nparts);
101 	spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
102 	for (i = 0; i < nparts; i++, p++) {
103 		unsigned long st_sector;
104 		unsigned int num_sectors;
105 
106 		st_sector = be32_to_cpu(p->start_cylinder) * spc;
107 		num_sectors = be32_to_cpu(p->num_sectors);
108 		if (num_sectors) {
109 			put_partition(state, slot, st_sector, num_sectors);
110 			state->parts[slot].flags = 0;
111 			if (use_vtoc) {
112 				if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
113 					state->parts[slot].flags |= ADDPART_FLAG_RAID;
114 				else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
115 					state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
116 			}
117 		}
118 		slot++;
119 	}
120 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
121 	put_dev_sector(sect);
122 	return 1;
123 }
124