xref: /openbmc/linux/block/partitions/sun.c (revision 2cf1c348)
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 
13 #define SUN_LABEL_MAGIC          0xDABE
14 #define SUN_VTOC_SANITY          0x600DDEEE
15 
16 enum {
17 	SUN_WHOLE_DISK = 5,
18 	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */
19 };
20 
21 int sun_partition(struct parsed_partitions *state)
22 {
23 	int i;
24 	__be16 csum;
25 	int slot = 1;
26 	__be16 *ush;
27 	Sector sect;
28 	struct sun_disklabel {
29 		unsigned char info[128];   /* Informative text string */
30 		struct sun_vtoc {
31 		    __be32 version;     /* Layout version */
32 		    char   volume[8];   /* Volume name */
33 		    __be16 nparts;      /* Number of partitions */
34 		    struct sun_info {           /* Partition hdrs, sec 2 */
35 			__be16 id;
36 			__be16 flags;
37 		    } infos[8];
38 		    __be16 padding;     /* Alignment padding */
39 		    __be32 bootinfo[3];  /* Info needed by mboot */
40 		    __be32 sanity;       /* To verify vtoc sanity */
41 		    __be32 reserved[10]; /* Free space */
42 		    __be32 timestamp[8]; /* Partition timestamp */
43 		} vtoc;
44 		__be32 write_reinstruct; /* sectors to skip, writes */
45 		__be32 read_reinstruct;  /* sectors to skip, reads */
46 		unsigned char spare[148]; /* Padding */
47 		__be16 rspeed;     /* Disk rotational speed */
48 		__be16 pcylcount;  /* Physical cylinder count */
49 		__be16 sparecyl;   /* extra sects per cylinder */
50 		__be16 obs1;       /* gap1 */
51 		__be16 obs2;       /* gap2 */
52 		__be16 ilfact;     /* Interleave factor */
53 		__be16 ncyl;       /* Data cylinder count */
54 		__be16 nacyl;      /* Alt. cylinder count */
55 		__be16 ntrks;      /* Tracks per cylinder */
56 		__be16 nsect;      /* Sectors per track */
57 		__be16 obs3;       /* bhead - Label head offset */
58 		__be16 obs4;       /* ppart - Physical Partition */
59 		struct sun_partition {
60 			__be32 start_cylinder;
61 			__be32 num_sectors;
62 		} partitions[8];
63 		__be16 magic;      /* Magic number */
64 		__be16 csum;       /* Label xor'd checksum */
65 	} * label;
66 	struct sun_partition *p;
67 	unsigned long spc;
68 	int use_vtoc;
69 	int nparts;
70 
71 	label = read_part_sector(state, 0, &sect);
72 	if (!label)
73 		return -1;
74 
75 	p = label->partitions;
76 	if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
77 /*		printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
78 		       state->disk->disk_name, be16_to_cpu(label->magic)); */
79 		put_dev_sector(sect);
80 		return 0;
81 	}
82 	/* Look at the checksum */
83 	ush = ((__be16 *) (label+1)) - 1;
84 	for (csum = 0; ush >= ((__be16 *) label);)
85 		csum ^= *ush--;
86 	if (csum) {
87 		printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
88 		       state->disk->disk_name);
89 		put_dev_sector(sect);
90 		return 0;
91 	}
92 
93 	/* Check to see if we can use the VTOC table */
94 	use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
95 		    (be32_to_cpu(label->vtoc.version) == 1) &&
96 		    (be16_to_cpu(label->vtoc.nparts) <= 8));
97 
98 	/* Use 8 partition entries if not specified in validated VTOC */
99 	nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
100 
101 	/*
102 	 * So that old Linux-Sun partitions continue to work,
103 	 * alow the VTOC to be used under the additional condition ...
104 	 */
105 	use_vtoc = use_vtoc || !(label->vtoc.sanity ||
106 				 label->vtoc.version || label->vtoc.nparts);
107 	spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
108 	for (i = 0; i < nparts; i++, p++) {
109 		unsigned long st_sector;
110 		unsigned int num_sectors;
111 
112 		st_sector = be32_to_cpu(p->start_cylinder) * spc;
113 		num_sectors = be32_to_cpu(p->num_sectors);
114 		if (num_sectors) {
115 			put_partition(state, slot, st_sector, num_sectors);
116 			state->parts[slot].flags = 0;
117 			if (use_vtoc) {
118 				if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
119 					state->parts[slot].flags |= ADDPART_FLAG_RAID;
120 				else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
121 					state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
122 			}
123 		}
124 		slot++;
125 	}
126 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
127 	put_dev_sector(sect);
128 	return 1;
129 }
130