1/*
2 *  fs/partitions/sgi.c
3 *
4 *  Code extracted from drivers/block/genhd.c
5 */
6
7#include "check.h"
8#include "sgi.h"
9
10struct sgi_disklabel {
11	__be32 magic_mushroom;		/* Big fat spliff... */
12	__be16 root_part_num;		/* Root partition number */
13	__be16 swap_part_num;		/* Swap partition number */
14	s8 boot_file[16];		/* Name of boot file for ARCS */
15	u8 _unused0[48];		/* Device parameter useless crapola.. */
16	struct sgi_volume {
17		s8 name[8];		/* Name of volume */
18		__be32 block_num;		/* Logical block number */
19		__be32 num_bytes;		/* How big, in bytes */
20	} volume[15];
21	struct sgi_partition {
22		__be32 num_blocks;		/* Size in logical blocks */
23		__be32 first_block;	/* First logical block */
24		__be32 type;		/* Type of this partition */
25	} partitions[16];
26	__be32 csum;			/* Disk label checksum */
27	__be32 _unused1;			/* Padding */
28};
29
30int sgi_partition(struct parsed_partitions *state, struct block_device *bdev)
31{
32	int i, csum;
33	__be32 magic;
34	int slot = 1;
35	unsigned int start, blocks;
36	__be32 *ui, cs;
37	Sector sect;
38	struct sgi_disklabel *label;
39	struct sgi_partition *p;
40	char b[BDEVNAME_SIZE];
41
42	label = (struct sgi_disklabel *) read_dev_sector(bdev, 0, &sect);
43	if (!label)
44		return -1;
45	p = &label->partitions[0];
46	magic = label->magic_mushroom;
47	if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
48		/*printk("Dev %s SGI disklabel: bad magic %08x\n",
49		       bdevname(bdev, b), be32_to_cpu(magic));*/
50		put_dev_sector(sect);
51		return 0;
52	}
53	ui = ((__be32 *) (label + 1)) - 1;
54	for(csum = 0; ui >= ((__be32 *) label);) {
55		cs = *ui--;
56		csum += be32_to_cpu(cs);
57	}
58	if(csum) {
59		printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
60		       bdevname(bdev, b));
61		put_dev_sector(sect);
62		return 0;
63	}
64	/* All SGI disk labels have 16 partitions, disks under Linux only
65	 * have 15 minor's.  Luckily there are always a few zero length
66	 * partitions which we don't care about so we never overflow the
67	 * current_minor.
68	 */
69	for(i = 0; i < 16; i++, p++) {
70		blocks = be32_to_cpu(p->num_blocks);
71		start  = be32_to_cpu(p->first_block);
72		if (blocks) {
73			put_partition(state, slot, start, blocks);
74			if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
75				state->parts[slot].flags = ADDPART_FLAG_RAID;
76		}
77		slot++;
78	}
79	printk("\n");
80	put_dev_sector(sect);
81	return 1;
82}
83