1/*
2 *  fs/partitions/amiga.c
3 *
4 *  Code extracted from drivers/block/genhd.c
5 *
6 *  Copyright (C) 1991-1998  Linus Torvalds
7 *  Re-organised Feb 1998 Russell King
8 */
9
10#include <linux/types.h>
11#include <linux/affs_hardblocks.h>
12
13#include "check.h"
14#include "amiga.h"
15
16static __inline__ u32
17checksum_block(__be32 *m, int size)
18{
19	u32 sum = 0;
20
21	while (size--)
22		sum += be32_to_cpu(*m++);
23	return sum;
24}
25
26int
27amiga_partition(struct parsed_partitions *state, struct block_device *bdev)
28{
29	Sector sect;
30	unsigned char *data;
31	struct RigidDiskBlock *rdb;
32	struct PartitionBlock *pb;
33	int start_sect, nr_sects, blk, part, res = 0;
34	int blksize = 1;	/* Multiplier for disk block size */
35	int slot = 1;
36	char b[BDEVNAME_SIZE];
37
38	for (blk = 0; ; blk++, put_dev_sector(sect)) {
39		if (blk == RDB_ALLOCATION_LIMIT)
40			goto rdb_done;
41		data = read_dev_sector(bdev, blk, &sect);
42		if (!data) {
43			if (warn_no_part)
44				printk("Dev %s: unable to read RDB block %d\n",
45				       bdevname(bdev, b), blk);
46			res = -1;
47			goto rdb_done;
48		}
49		if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
50			continue;
51
52		rdb = (struct RigidDiskBlock *)data;
53		if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
54			break;
55		/* Try again with 0xdc..0xdf zeroed, Windows might have
56		 * trashed it.
57		 */
58		*(__be32 *)(data+0xdc) = 0;
59		if (checksum_block((__be32 *)data,
60				be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
61			printk("Warning: Trashed word at 0xd0 in block %d "
62				"ignored in checksum calculation\n",blk);
63			break;
64		}
65
66		printk("Dev %s: RDB in block %d has bad checksum\n",
67			       bdevname(bdev, b), blk);
68	}
69
70	/* blksize is blocks per 512 byte standard block */
71	blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
72
73	printk(" RDSK (%d)", blksize * 512);	/* Be more informative */
74	blk = be32_to_cpu(rdb->rdb_PartitionList);
75	put_dev_sector(sect);
76	for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
77		blk *= blksize;	/* Read in terms partition table understands */
78		data = read_dev_sector(bdev, blk, &sect);
79		if (!data) {
80			if (warn_no_part)
81				printk("Dev %s: unable to read partition block %d\n",
82				       bdevname(bdev, b), blk);
83			res = -1;
84			goto rdb_done;
85		}
86		pb  = (struct PartitionBlock *)data;
87		blk = be32_to_cpu(pb->pb_Next);
88		if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
89			continue;
90		if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
91			continue;
92
93		/* Tell Kernel about it */
94
95		nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
96			    be32_to_cpu(pb->pb_Environment[9])) *
97			   be32_to_cpu(pb->pb_Environment[3]) *
98			   be32_to_cpu(pb->pb_Environment[5]) *
99			   blksize;
100		if (!nr_sects)
101			continue;
102		start_sect = be32_to_cpu(pb->pb_Environment[9]) *
103			     be32_to_cpu(pb->pb_Environment[3]) *
104			     be32_to_cpu(pb->pb_Environment[5]) *
105			     blksize;
106		put_partition(state,slot++,start_sect,nr_sects);
107		{
108			/* Be even more informative to aid mounting */
109			char dostype[4];
110			__be32 *dt = (__be32 *)dostype;
111			*dt = pb->pb_Environment[16];
112			if (dostype[3] < ' ')
113				printk(" (%c%c%c^%c)",
114					dostype[0], dostype[1],
115					dostype[2], dostype[3] + '@' );
116			else
117				printk(" (%c%c%c%c)",
118					dostype[0], dostype[1],
119					dostype[2], dostype[3]);
120			printk("(res %d spb %d)",
121				be32_to_cpu(pb->pb_Environment[6]),
122				be32_to_cpu(pb->pb_Environment[4]));
123		}
124		res = 1;
125	}
126	printk("\n");
127
128rdb_done:
129	return res;
130}
131