1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  fs/partitions/atari.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 <linux/ctype.h>
 12#include "check.h"
 13#include "atari.h"
 14
 15/* ++guenther: this should be settable by the user ("make config")?.
 16 */
 17#define ICD_PARTS
 18
 19/* check if a partition entry looks valid -- Atari format is assumed if at
 20   least one of the primary entries is ok this way */
 21#define	VALID_PARTITION(pi,hdsiz)					     \
 22    (((pi)->flg & 1) &&							     \
 23     isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
 24     be32_to_cpu((pi)->st) <= (hdsiz) &&				     \
 25     be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
 26
 27static inline int OK_id(char *s)
 28{
 29	return  memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
 30		memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
 31		memcmp (s, "RAW", 3) == 0 ;
 32}
 33
 34int atari_partition(struct parsed_partitions *state)
 35{
 36	Sector sect;
 37	struct rootsector *rs;
 38	struct partition_info *pi;
 39	u32 extensect;
 40	u32 hd_size;
 41	int slot;
 42#ifdef ICD_PARTS
 43	int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
 44#endif
 45
 46	/*
 47	 * ATARI partition scheme supports 512 lba only.  If this is not
 48	 * the case, bail early to avoid miscalculating hd_size.
 49	 */
 50	if (queue_logical_block_size(state->disk->queue) != 512)
 51		return 0;
 52
 53	rs = read_part_sector(state, 0, &sect);
 54	if (!rs)
 55		return -1;
 56
 57	/* Verify this is an Atari rootsector: */
 58	hd_size = get_capacity(state->disk);
 59	if (!VALID_PARTITION(&rs->part[0], hd_size) &&
 60	    !VALID_PARTITION(&rs->part[1], hd_size) &&
 61	    !VALID_PARTITION(&rs->part[2], hd_size) &&
 62	    !VALID_PARTITION(&rs->part[3], hd_size)) {
 63		/*
 64		 * if there's no valid primary partition, assume that no Atari
 65		 * format partition table (there's no reliable magic or the like
 66	         * :-()
 67		 */
 68		put_dev_sector(sect);
 69		return 0;
 70	}
 71
 72	pi = &rs->part[0];
 73	strlcat(state->pp_buf, " AHDI", PAGE_SIZE);
 74	for (slot = 1; pi < &rs->part[4] && slot < state->limit; slot++, pi++) {
 75		struct rootsector *xrs;
 76		Sector sect2;
 77		ulong partsect;
 78
 79		if ( !(pi->flg & 1) )
 80			continue;
 81		/* active partition */
 82		if (memcmp (pi->id, "XGM", 3) != 0) {
 83			/* we don't care about other id's */
 84			put_partition (state, slot, be32_to_cpu(pi->st),
 85					be32_to_cpu(pi->siz));
 86			continue;
 87		}
 88		/* extension partition */
 89#ifdef ICD_PARTS
 90		part_fmt = 1;
 91#endif
 92		strlcat(state->pp_buf, " XGM<", PAGE_SIZE);
 93		partsect = extensect = be32_to_cpu(pi->st);
 94		while (1) {
 95			xrs = read_part_sector(state, partsect, &sect2);
 96			if (!xrs) {
 97				printk (" block %ld read failed\n", partsect);
 98				put_dev_sector(sect);
 99				return -1;
100			}
101
102			/* ++roman: sanity check: bit 0 of flg field must be set */
103			if (!(xrs->part[0].flg & 1)) {
104				printk( "\nFirst sub-partition in extended partition is not valid!\n" );
105				put_dev_sector(sect2);
106				break;
107			}
108
109			put_partition(state, slot,
110				   partsect + be32_to_cpu(xrs->part[0].st),
111				   be32_to_cpu(xrs->part[0].siz));
112
113			if (!(xrs->part[1].flg & 1)) {
114				/* end of linked partition list */
115				put_dev_sector(sect2);
116				break;
117			}
118			if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
119				printk("\nID of extended partition is not XGM!\n");
120				put_dev_sector(sect2);
121				break;
122			}
123
124			partsect = be32_to_cpu(xrs->part[1].st) + extensect;
125			put_dev_sector(sect2);
126			if (++slot == state->limit) {
127				printk( "\nMaximum number of partitions reached!\n" );
128				break;
129			}
130		}
131		strlcat(state->pp_buf, " >", PAGE_SIZE);
132	}
133#ifdef ICD_PARTS
134	if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
135		pi = &rs->icdpart[0];
136		/* sanity check: no ICD format if first partition invalid */
137		if (OK_id(pi->id)) {
138			strlcat(state->pp_buf, " ICD<", PAGE_SIZE);
139			for (; pi < &rs->icdpart[8] && slot < state->limit; slot++, pi++) {
140				/* accept only GEM,BGM,RAW,LNX,SWP partitions */
141				if (!((pi->flg & 1) && OK_id(pi->id)))
142					continue;
143				put_partition (state, slot,
144						be32_to_cpu(pi->st),
145						be32_to_cpu(pi->siz));
146			}
147			strlcat(state->pp_buf, " >", PAGE_SIZE);
148		}
149	}
150#endif
151	put_dev_sector(sect);
152
153	strlcat(state->pp_buf, "\n", PAGE_SIZE);
154
155	return 1;
156}