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/*

 *  Code extracted from

 *  linux/kernel/hd.c

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *

 *

 *  Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug

 *  in the early extended-partition checks and added DM partitions

 *

 *  Support for DiskManager v6.0x added by Mark Lord,

 *  with information provided by OnTrack.  This now works for linux fdisk

 *  and LILO, as well as loadlin and bootln.  Note that disks other than

 *  /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1).

 *

 *  More flexible handling of extended partitions - aeb, 950831

 *

 *  Check partition table on IDE disks for common CHS translations

 */

#include <linux/config.h>

#include <linux/fs.h>

#include <linux/genhd.h>

#include <linux/kernel.h>

#include <linux/major.h>

#include <linux/string.h>

#ifdef CONFIG_BLK_DEV_INITRD

#include <linux/blk.h>

#endif

#include <asm/system.h>

/*

 * Many architectures don't like unaligned accesses, which is

 * frequently the case with the nr_sects and start_sect partition

 * table entries.

 */

#include <asm/unaligned.h>

#define SYS_IND(p)      get_unaligned(&p->sys_ind)

#define NR_SECTS(p)     get_unaligned(&p->nr_sects)

#define START_SECT(p)   get_unaligned(&p->start_sect)

struct gendisk *gendisk_head = NULL;

static int current_minor = 0;

extern int *blk_size[];

extern void rd_load(void);

extern void initrd_load(void);

extern int chr_dev_init(void);

extern int blk_dev_init(void);

#ifdef CONFIG_BLK_DEV_DAC960

extern void DAC960_Initialize(void);

#endif

extern int scsi_dev_init(void);

extern int net_dev_init(void);

/*

 * disk_name() is used by genhd.c and md.c.

 * It formats the devicename of the indicated disk

 * into the supplied buffer, and returns a pointer

 * to that same buffer (for convenience).

 */

char *disk_name (struct gendisk *hd, int minor, char *buf)

{

        unsigned int part;

        const char *maj = hd->major_name;

        char unit = (minor >> hd->minor_shift) + 'a';

#ifdef CONFIG_BLK_DEV_IDE

        /*

         * IDE devices use multiple major numbers, but the drives

         * are named as:  {hda,hdb}, {hdc,hdd}, {hde,hdf}, {hdg,hdh}..

         * This requires special handling here.

         */

        switch (hd->major) {

                case IDE3_MAJOR:

                        unit += 2;

                case IDE2_MAJOR:

                        unit += 2;

                case IDE1_MAJOR:

                        unit += 2;

                case IDE0_MAJOR:

                        maj = "hd";

        }

#endif

        if (hd->major >= DAC960_MAJOR+0 && hd->major <= DAC960_MAJOR+7)

          {

            int controller = hd->major - DAC960_MAJOR;

            int partition = minor & ((1 << hd->minor_shift) - 1);

            if (partition == 0)

              sprintf(buf, "%s/c%dd%d",

                      maj, controller, minor >> hd->minor_shift);

            else sprintf(buf, "%s/c%dd%dp%d",

                         maj, controller, minor >> hd->minor_shift, partition);

            return buf;

          }

#if defined(CONFIG_BLK_CPQ_DA) || defined(CONFIG_BLK_CPQ_DA_MODULE)

        if (hd->major >= COMPAQ_SMART2_MAJOR && hd->major <= COMPAQ_SMART2_MAJOR+7) {

                int ctlr = hd->major - COMPAQ_SMART2_MAJOR;

                int disk = minor >> hd->minor_shift;

                int part = minor & (( 1 << hd->minor_shift) - 1);

                if (part == 0)

                        sprintf(buf, "%s/c%dd%d", maj, ctlr, disk);

                else

                        sprintf(buf, "%s/c%dd%dp%d", maj, ctlr, disk, part);

                return buf;

        }

#endif

        part = minor & ((1 << hd->minor_shift) - 1);

        if (part)

                sprintf(buf, "%s%c%d", maj, unit, part);

        else

                sprintf(buf, "%s%c", maj, unit);

        return buf;

}

static void add_partition (struct gendisk *hd, int minor, int start, int size)

{

        char buf[40];

        hd->part[minor].start_sect = start;

        hd->part[minor].nr_sects   = size;

        if (hd->major >= DAC960_MAJOR+0 && hd->major <= DAC960_MAJOR+7)

                printk(" p%d", (minor & ((1 << hd->minor_shift) - 1)));

        else

#if defined(CONFIG_BLK_CPQ_DA) || defined(CONFIG_BLK_CPQ_DA_MODULE)

        if (hd->major >= COMPAQ_SMART2_MAJOR && hd->major <= COMPAQ_SMART2_MAJOR+7)

                printk(" p%d", (minor & ((1 << hd->minor_shift) - 1)));

        else

#endif

                printk(" %s", disk_name(hd, minor, buf));

}

static inline int is_extended_partition(struct partition *p)

{

        return (SYS_IND(p) == DOS_EXTENDED_PARTITION ||

                SYS_IND(p) == WIN98_EXTENDED_PARTITION ||

                SYS_IND(p) == LINUX_EXTENDED_PARTITION);

}

#ifdef CONFIG_MSDOS_PARTITION

/*

 * Create devices for each logical partition in an extended partition.

 * The logical partitions form a linked list, with each entry being

 * a partition table with two entries.  The first entry

 * is the real data partition (with a start relative to the partition

 * table start).  The second is a pointer to the next logical partition

 * (with a start relative to the entire extended partition).

 * We do not create a Linux partition for the partition tables, but

 * only for the actual data partitions.

 */

static void extended_partition(struct gendisk *hd, kdev_t dev)

{

        struct buffer_head *bh;

        struct partition *p;

        unsigned long first_sector, first_size, this_sector, this_size;

        int mask = (1 << hd->minor_shift) - 1;

        int i;

        first_sector = hd->part[MINOR(dev)].start_sect;

        first_size = hd->part[MINOR(dev)].nr_sects;

        this_sector = first_sector;

        while (1) {

                if ((current_minor & mask) == 0)

                        return;

                if (!(bh = bread(dev,0,1024)))

                        return;

          /*

           * This block is from a device that we're about to stomp on.

           * So make sure nobody thinks this block is usable.

           */

                bh->b_state = 0;

                if (*(unsigned short *) (bh->b_data+510) != 0xAA55)

                        goto done;

                p = (struct partition *) (0x1BE + bh->b_data);

                this_size = hd->part[MINOR(dev)].nr_sects;

                /*

                 * Usually, the first entry is the real data partition,

                 * the 2nd entry is the next extended partition, or empty,

                 * and the 3rd and 4th entries are unused.

                 * However, DRDOS sometimes has the extended partition as

                 * the first entry (when the data partition is empty),

                 * and OS/2 seems to use all four entries.

                 */

                /*

                 * First process the data partition(s)

                 */

                for (i=0; i<4; i++, p++) {

                    if (!NR_SECTS(p) || is_extended_partition(p))

                      continue;

                    /* Check the 3rd and 4th entries -

                       these sometimes contain random garbage */

                    if (i >= 2

                        && START_SECT(p) + NR_SECTS(p) > this_size

                        && (this_sector + START_SECT(p) < first_sector ||

                            this_sector + START_SECT(p) + NR_SECTS(p) >

                             first_sector + first_size))

                      continue;

                    add_partition(hd, current_minor, this_sector+START_SECT(p), NR_SECTS(p));

                    current_minor++;

                    if ((current_minor & mask) == 0)

                      goto done;

                }

                /*

                 * Next, process the (first) extended partition, if present.

                 * (So far, there seems to be no reason to make

                 *  extended_partition()  recursive and allow a tree

                 *  of extended partitions.)

                 * It should be a link to the next logical partition.

                 * Create a minor for this just long enough to get the next

                 * partition table.  The minor will be reused for the next

                 * data partition.

                 */

                p -= 4;

                for (i=0; i<4; i++, p++)

                  if(NR_SECTS(p) && is_extended_partition(p))

                    break;

                if (i == 4)

                  goto done;     /* nothing left to do */

                hd->part[current_minor].nr_sects = NR_SECTS(p);

                hd->part[current_minor].start_sect = first_sector + START_SECT(p);

                this_sector = first_sector + START_SECT(p);

                dev = MKDEV(hd->major, current_minor);

                brelse(bh);

        }

done:

        brelse(bh);

}

#ifdef CONFIG_BSD_DISKLABEL

/*

 * Create devices for BSD partitions listed in a disklabel, under a

 * dos-like partition. See extended_partition() for more information.

 */

static void bsd_disklabel_partition(struct gendisk *hd, kdev_t dev)

{

        struct buffer_head *bh;

        struct bsd_disklabel *l;

        struct bsd_partition *p;

        int mask = (1 << hd->minor_shift) - 1;

        if (!(bh = bread(dev,0,1024)))

                return;

        bh->b_state = 0;

        l = (struct bsd_disklabel *) (bh->b_data+512);

        if (l->d_magic != BSD_DISKMAGIC) {

                brelse(bh);

                return;

        }

        p = &l->d_partitions[0];

        while (p - &l->d_partitions[0] <= BSD_MAXPARTITIONS) {

                if ((current_minor & mask) >= (4 + hd->max_p))

                        break;

                if (p->p_fstype != BSD_FS_UNUSED) {

                        add_partition(hd, current_minor, p->p_offset, p->p_size);

                        current_minor++;

                }

                p++;

        }

        brelse(bh);

}

#endif

static int msdos_partition(struct gendisk *hd, kdev_t dev, unsigned long first_sector)

{

        int i, minor = current_minor;

        struct buffer_head *bh;

        struct partition *p;

        unsigned char *data;

        int mask = (1 << hd->minor_shift) - 1;

#ifdef CONFIG_BLK_DEV_IDE

        int tested_for_xlate = 0;

read_mbr:

#endif

        if (!(bh = bread(dev,0,1024))) {

                printk(" unable to read partition table\n");

                return -1;

        }

        data = bh->b_data;

        /* In some cases we modify the geometry    */

        /*  of the drive (below), so ensure that   */

        /*  nobody else tries to re-use this data. */

        bh->b_state = 0;

#ifdef CONFIG_BLK_DEV_IDE

check_table:

#endif

        if (*(unsigned short *)  (0x1fe + data) != 0xAA55) {

                brelse(bh);

                return 0;

        }

        p = (struct partition *) (0x1be + data);

#ifdef CONFIG_BLK_DEV_IDE

        if (!tested_for_xlate++) {      /* Do this only once per disk */

                /*

                 * Look for various forms of IDE disk geometry translation

                 */

                extern int ide_xlate_1024(kdev_t, int, const char *);

                unsigned int sig = *(unsigned short *)(data + 2);

                if (SYS_IND(p) == EZD_PARTITION) {

                        /*

                         * The remainder of the disk must be accessed using

                         * a translated geometry that reduces the number of

                         * apparent cylinders to less than 1024 if possible.

                         *

                         * ide_xlate_1024() will take care of the necessary

                         * adjustments to fool fdisk/LILO and partition check.

                         */

                        if (ide_xlate_1024(dev, -1, " [EZD]")) {

                                data += 512;

                                goto check_table;

                        }

                } else if (SYS_IND(p) == DM6_PARTITION) {

                        /*

                         * Everything on the disk is offset by 63 sectors,

                         * including a "new" MBR with its own partition table,

                         * and the remainder of the disk must be accessed using

                         * a translated geometry that reduces the number of

                         * apparent cylinders to less than 1024 if possible.

                         *

                         * ide_xlate_1024() will take care of the necessary

                         * adjustments to fool fdisk/LILO and partition check.

                         */

                        if (ide_xlate_1024(dev, 1, " [DM6:DDO]")) {

                                brelse(bh);

                                goto read_mbr;  /* start over with new MBR */

                        }

                } else if (sig <= 0x1ae && *(unsigned short *)(data + sig) == 0x55AA

                         && (1 & *(unsigned char *)(data + sig + 2)) )

                {

                        /*

                         * DM6 signature in MBR, courtesy of OnTrack

                         */

                        (void) ide_xlate_1024 (dev, 0, " [DM6:MBR]");

                } else if (SYS_IND(p) == DM6_AUX1PARTITION || SYS_IND(p) == DM6_AUX3PARTITION) {

                        /*

                         * DM6 on other than the first (boot) drive

                         */

                        (void) ide_xlate_1024(dev, 0, " [DM6:AUX]");

                } else {

                        /*

                         * Examine the partition table for common translations.

                         * This is necessary for drives for situations where

                         * the translated geometry is unavailable from the BIOS.

                         */

                        for (i = 0; i < 4 ; i++) {

                                struct partition *q = &p[i];

                                if (NR_SECTS(q)

                                   && (q->sector & 63) == 1

                                   && (q->end_sector & 63) == 63) {

                                        unsigned int heads = q->end_head + 1;

                                        if (heads == 32 || heads == 64 ||

                                            heads == 128 || heads == 240 ||

                                            heads == 255) {

                                                (void) ide_xlate_1024(dev, heads, " [PTBL]");

                                                break;

                                        }

                                }

                        }

                }

        }

#endif  /* CONFIG_BLK_DEV_IDE */

        current_minor += 4;  /* first "extra" minor (for extended partitions) */

        for (i=1 ; i<=4 ; minor++,i++,p++) {

                if (!NR_SECTS(p))

                        continue;

                add_partition(hd, minor, first_sector+START_SECT(p), NR_SECTS(p));

                if (is_extended_partition(p)) {

                        printk(" <");

                        /*

                         * If we are rereading the partition table, we need

                         * to set the size of the partition so that we will

                         * be able to bread the block containing the extended

                         * partition info.

                         */

                        hd->sizes[minor] = hd->part[minor].nr_sects

                                >> (BLOCK_SIZE_BITS - 9);

                        extended_partition(hd, MKDEV(hd->major, minor));

                        printk(" >");

                        /* prevent someone doing mkfs or mkswap on an

                           extended partition, but leave room for LILO */

                        if (hd->part[minor].nr_sects > 2)

                                hd->part[minor].nr_sects = 2;

                }

#ifdef CONFIG_BSD_DISKLABEL

                if (SYS_IND(p) == BSD_PARTITION) {

                        printk(" <");

                        bsd_disklabel_partition(hd, MKDEV(hd->major, minor));

                        printk(" >");

                }

#endif

        }

        /*

         *  Check for old-style Disk Manager partition table

         */

        if (*(unsigned short *) (data+0xfc) == 0x55AA) {

                p = (struct partition *) (0x1be + data);

                for (i = 4 ; i < 16 ; i++, current_minor++) {

                        p--;

                        if ((current_minor & mask) == 0)

                                break;

                        if (!(START_SECT(p) && NR_SECTS(p)))

                                continue;

                        add_partition(hd, current_minor, START_SECT(p), NR_SECTS(p));

                }

        }

        printk("\n");

        brelse(bh);

        return 1;

}

#endif /* CONFIG_MSDOS_PARTITION */

#ifdef CONFIG_OSF_PARTITION

static int osf_partition(struct gendisk *hd, unsigned int dev, unsigned long first_sector)

{

        int i;

        int mask = (1 << hd->minor_shift) - 1;

        struct buffer_head *bh;

        struct disklabel {

                u32 d_magic;

                u16 d_type,d_subtype;

                u8 d_typename[16];

                u8 d_packname[16];

                u32 d_secsize;

                u32 d_nsectors;

                u32 d_ntracks;

                u32 d_ncylinders;

                u32 d_secpercyl;

                u32 d_secprtunit;

                u16 d_sparespertrack;

                u16 d_sparespercyl;

                u32 d_acylinders;

                u16 d_rpm, d_interleave, d_trackskew, d_cylskew;

                u32 d_headswitch, d_trkseek, d_flags;

                u32 d_drivedata[5];

                u32 d_spare[5];

                u32 d_magic2;

                u16 d_checksum;

                u16 d_npartitions;

                u32 d_bbsize, d_sbsize;

                struct d_partition {

                        u32 p_size;

                        u32 p_offset;

                        u32 p_fsize;

                        u8  p_fstype;

                        u8  p_frag;

                        u16 p_cpg;

                } d_partitions[8];

        } * label;

        struct d_partition * partition;

#define DISKLABELMAGIC (0x82564557UL)

        if (!(bh = bread(dev,0,1024))) {

                printk("unable to read partition table\n");

                return -1;

        }

        label = (struct disklabel *) (bh->b_data+64);

        partition = label->d_partitions;

        if (label->d_magic != DISKLABELMAGIC) {

                printk("magic: %08x\n", label->d_magic);

                brelse(bh);

                return 0;

        }

        if (label->d_magic2 != DISKLABELMAGIC) {

                printk("magic2: %08x\n", label->d_magic2);

                brelse(bh);

                return 0;

        }

        for (i = 0 ; i < label->d_npartitions; i++, partition++) {

                if ((current_minor & mask) == 0)

                        break;

                if (partition->p_size)

                        add_partition(hd, current_minor,

                                first_sector+partition->p_offset,

                                partition->p_size);

                current_minor++;

        }

        printk("\n");

        brelse(bh);

        return 1;

}

#endif /* CONFIG_OSF_PARTITION */

#ifdef CONFIG_SUN_PARTITION

static int sun_partition(struct gendisk *hd, kdev_t dev, unsigned long first_sector)

{

        int i, csum;

        unsigned short *ush;

        struct buffer_head *bh;

        struct sun_disklabel {

                unsigned char info[128];   /* Informative text string */

                unsigned char spare[292];  /* Boot information etc. */

                unsigned short rspeed;     /* Disk rotational speed */

                unsigned short pcylcount;  /* Physical cylinder count */

                unsigned short sparecyl;   /* extra sects per cylinder */

                unsigned char spare2[4];   /* More magic... */

                unsigned short ilfact;     /* Interleave factor */

                unsigned short ncyl;       /* Data cylinder count */

                unsigned short nacyl;      /* Alt. cylinder count */

                unsigned short ntrks;      /* Tracks per cylinder */

                unsigned short nsect;      /* Sectors per track */

                unsigned char spare3[4];   /* Even more magic... */

                struct sun_partition {

                        __u32 start_cylinder;

                        __u32 num_sectors;

                } partitions[8];

                unsigned short magic;      /* Magic number */

                unsigned short csum;       /* Label xor'd checksum */

        } * label;

        struct sun_partition *p;

        int other_endian;

        unsigned long spc;

#define SUN_LABEL_MAGIC          0xDABE

#define SUN_LABEL_MAGIC_SWAPPED  0xBEDA

/* No need to optimize these macros since they are called only when reading

 * the partition table. This occurs only at each disk change. */

#define SWAP16(x)  (other_endian ? (((__u16)(x) & 0xFF) << 8) \

                                 | (((__u16)(x) & 0xFF00) >> 8) \

                                 : (__u16)(x))

#define SWAP32(x)  (other_endian ? (((__u32)(x) & 0xFF) << 24) \

                                 | (((__u32)(x) & 0xFF00) << 8) \

                                 | (((__u32)(x) & 0xFF0000) >> 8) \

                                 | (((__u32)(x) & 0xFF000000) >> 24) \

                                 : (__u32)(x))

        if(!(bh = bread(dev, 0, 1024))) {

                printk("Dev %s: unable to read partition table\n",

                       kdevname(dev));

                return -1;

        }

        label = (struct sun_disklabel *) bh->b_data;

        p = label->partitions;

        if (label->magic != SUN_LABEL_MAGIC && label->magic != SUN_LABEL_MAGIC_SWAPPED) {

                printk("Dev %s Sun disklabel: bad magic %04x\n",

                       kdevname(dev), label->magic);

                brelse(bh);

                return 0;

        }

        other_endian = (label->magic == SUN_LABEL_MAGIC_SWAPPED);

        /* Look at the checksum */

        ush = ((unsigned short *) (label+1)) - 1;

        for(csum = 0; ush >= ((unsigned short *) label);)

                csum ^= *ush--;

        if(csum) {

                printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",

                       kdevname(dev));

                brelse(bh);

                return 0;

        }

        /* All Sun disks have 8 partition entries */

        spc = SWAP16(label->ntrks) * SWAP16(label->nsect);

        for(i=0; i < 8; i++, p++) {

                unsigned long st_sector;

                /* We register all partitions, even if zero size, so that

                 * the minor numbers end up ok as per SunOS interpretation.

                 */

                st_sector = first_sector + SWAP32(p->start_cylinder) * spc;

                add_partition(hd, current_minor, st_sector, SWAP32(p->num_sectors));

                current_minor++;

        }

        printk("\n");

        brelse(bh);

        return 1;

#undef SWAP16

#undef SWAP32

}

#endif /* CONFIG_SUN_PARTITION */

#ifdef CONFIG_AMIGA_PARTITION

#include <asm/byteorder.h>

#include <linux/affs_hardblocks.h>

static __inline__ __u32

checksum_block(__u32 *m, int size)

{

        __u32 sum = 0;

        while (size--)

                sum += htonl(*m++);

        return sum;

}

static int

amiga_partition(struct gendisk *hd, unsigned int dev, unsigned long first_sector)

{

        struct buffer_head      *bh;

        struct RigidDiskBlock   *rdb;

        struct PartitionBlock   *pb;

        int                      start_sect;

        int                      nr_sects;

        int                      blk;

        int                      part, res;

        set_blocksize(dev,512);

        res = 0;

        for (blk = 0; blk < RDB_ALLOCATION_LIMIT; blk++) {

                if(!(bh = bread(dev,blk,512))) {

                        printk("Dev %d: unable to read RDB block %d\n",dev,blk);

                        goto rdb_done;

                }

                if (*(__u32 *)bh->b_data == htonl(IDNAME_RIGIDDISK)) {

                        rdb = (struct RigidDiskBlock *)bh->b_data;

                        if (checksum_block((__u32 *)bh->b_data,htonl(rdb->rdb_SummedLongs) & 0x7F)) {

                                printk("Dev %d: RDB in block %d has bad checksum\n",dev,blk);

                                brelse(bh);

                                continue;

                        }

                        printk(" RDSK");

                        blk = htonl(rdb->rdb_PartitionList);

                        brelse(bh);