sun.c

  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
 16enum {
 17	SUN_WHOLE_DISK = 5,
 18	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */
 19};
 20
 21int 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		put_dev_sector(sect);
 78		return 0;
 79	}
 80	/* Look at the checksum */
 81	ush = ((__be16 *) (label+1)) - 1;
 82	for (csum = 0; ush >= ((__be16 *) label);)
 83		csum ^= *ush--;
 84	if (csum) {
 85		printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
 86		       state->disk->disk_name);
 87		put_dev_sector(sect);
 88		return 0;
 89	}
 90
 91	/* Check to see if we can use the VTOC table */
 92	use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
 93		    (be32_to_cpu(label->vtoc.version) == 1) &&
 94		    (be16_to_cpu(label->vtoc.nparts) <= 8));
 95
 96	/* Use 8 partition entries if not specified in validated VTOC */
 97	nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
 98
 99	/*
100	 * So that old Linux-Sun partitions continue to work,
101	 * alow the VTOC to be used under the additional condition ...
102	 */
103	use_vtoc = use_vtoc || !(label->vtoc.sanity ||
104				 label->vtoc.version || label->vtoc.nparts);
105	spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
106	for (i = 0; i < nparts; i++, p++) {
107		unsigned long st_sector;
108		unsigned int num_sectors;
109
110		st_sector = be32_to_cpu(p->start_cylinder) * spc;
111		num_sectors = be32_to_cpu(p->num_sectors);
112		if (num_sectors) {
113			put_partition(state, slot, st_sector, num_sectors);
114			state->parts[slot].flags = 0;
115			if (use_vtoc) {
116				if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
117					state->parts[slot].flags |= ADDPART_FLAG_RAID;
118				else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
119					state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
120			}
121		}
122		slot++;
123	}
124	strlcat(state->pp_buf, "\n", PAGE_SIZE);
125	put_dev_sector(sect);
126	return 1;
127}