/*
 * File...........: linux/fs/partitions/ibm.c
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *                  Volker Sameske <sameske@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
 */

#include <linux/buffer_head.h>
#include <linux/hdreg.h>
#include <linux/slab.h>
#include <asm/dasd.h>
#include <asm/ebcdic.h>
#include <asm/uaccess.h>
#include <asm/vtoc.h>

#include "check.h"
#include "ibm.h"

/*
 * compute the block number from a
 * cyl-cyl-head-head structure
 */
static sector_t
cchh2blk (struct vtoc_cchh *ptr, struct hd_geometry *geo) {

        sector_t cyl;
        __u16 head;

        /*decode cylinder and heads for large volumes */
        cyl = ptr->hh & 0xFFF0;
        cyl <<= 12;
        cyl |= ptr->cc;
        head = ptr->hh & 0x000F;
        return cyl * geo->heads * geo->sectors +
               head * geo->sectors;
}

/*
 * compute the block number from a
 * cyl-cyl-head-head-block structure
 */
static sector_t
cchhb2blk (struct vtoc_cchhb *ptr, struct hd_geometry *geo) {

        sector_t cyl;
        __u16 head;

        /*decode cylinder and heads for large volumes */
        cyl = ptr->hh & 0xFFF0;
        cyl <<= 12;
        cyl |= ptr->cc;
        head = ptr->hh & 0x000F;
        return  cyl * geo->heads * geo->sectors +
                head * geo->sectors +
                ptr->b;
}

/*
 */
int
ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
{
        int blocksize, res;
        loff_t i_size, offset, size, fmt_size;
        dasd_information2_t *info;
        struct hd_geometry *geo;
        char type[5] = {0,};
        char name[7] = {0,};
        union label_t {
                struct vtoc_volume_label_cdl vol;
                struct vtoc_volume_label_ldl lnx;
                struct vtoc_cms_label cms;
        } *label;
        unsigned char *data;
        Sector sect;

        res = 0;
        blocksize = bdev_logical_block_size(bdev);
        if (blocksize <= 0)
                goto out_exit;
        i_size = i_size_read(bdev->bd_inode);
        if (i_size == 0)
                goto out_exit;

        info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
        if (info == NULL)
                goto out_exit;
        geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
        if (geo == NULL)
                goto out_nogeo;
        label = kmalloc(sizeof(union label_t), GFP_KERNEL);
        if (label == NULL)
                goto out_nolab;

        if (ioctl_by_bdev(bdev, BIODASDINFO2, (unsigned long)info) != 0 ||
            ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
                goto out_freeall;

        /*
         * Get volume label, extract name and type.
         */
        data = read_dev_sector(bdev, info->label_block*(blocksize/512), &sect);
        if (data == NULL)
                goto out_readerr;

        memcpy(label, data, sizeof(union label_t));
        put_dev_sector(sect);

        if ((!info->FBA_layout) && (!strcmp(info->type, "ECKD"))) {
                strncpy(type, label->vol.vollbl, 4);
                strncpy(name, label->vol.volid, 6);
        } else {
                strncpy(type, label->lnx.vollbl, 4);
                strncpy(name, label->lnx.volid, 6);
        }
        EBCASC(type, 4);
        EBCASC(name, 6);

        res = 1;

        /*
         * Three different formats: LDL, CDL and unformated disk
         *
         * identified by info->format
         *
         * unformated disks we do not have to care about
         */
        if (info->format == DASD_FORMAT_LDL) {
                if (strncmp(type, "CMS1", 4) == 0) {
                        /*
                         * VM style CMS1 labeled disk
                         */
                        blocksize = label->cms.block_size;
                        if (label->cms.disk_offset != 0) {
                                printk("CMS1/%8s(MDSK):", name);
                                /* disk is reserved minidisk */
                                offset = label->cms.disk_offset;
                                size = (label->cms.block_count - 1)
                                        * (blocksize >> 9);
                        } else {
                                printk("CMS1/%8s:", name);
                                offset = (info->label_block + 1);
                                size = label->cms.block_count
                                        * (blocksize >> 9);
                        }
                        put_partition(state, 1, offset*(blocksize >> 9),
                                      size-offset*(blocksize >> 9));
                } else {
                        if (strncmp(type, "LNX1", 4) == 0) {
                                printk("LNX1/%8s:", name);
                                if (label->lnx.ldl_version == 0xf2) {
                                        fmt_size = label->lnx.formatted_blocks
                                                * (blocksize >> 9);
                                } else if (!strcmp(info->type, "ECKD")) {
                                        /* formated w/o large volume support */
                                        fmt_size = geo->cylinders * geo->heads
                                              * geo->sectors * (blocksize >> 9);
                                } else {
                                        /* old label and no usable disk geometry
                                         * (e.g. DIAG) */
                                        fmt_size = i_size >> 9;
                                }
                                size = i_size >> 9;
                                if (fmt_size < size)
                                        size = fmt_size;
                                offset = (info->label_block + 1);
                        } else {
                                /* unlabeled disk */
                                printk("(nonl)");
                                size = i_size >> 9;
                                offset = (info->label_block + 1);
                        }
                        put_partition(state, 1, offset*(blocksize >> 9),
                                      size-offset*(blocksize >> 9));
                }
        } else if (info->format == DASD_FORMAT_CDL) {
                /*
                 * New style CDL formatted disk
                 */
                sector_t blk;
                int counter;

                /*
                 * check if VOL1 label is available
                 * if not, something is wrong, skipping partition detection
                 */
                if (strncmp(type, "VOL1",  4) == 0) {
                        printk("VOL1/%8s:", name);
                        /*
                         * get block number and read then go through format1
                         * labels
                         */
                        blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
                        counter = 0;
                        data = read_dev_sector(bdev, blk * (blocksize/512),
                                               &sect);
                        while (data != NULL) {
                                struct vtoc_format1_label f1;

                                memcpy(&f1, data,
                                       sizeof(struct vtoc_format1_label));
                                put_dev_sector(sect);

                                /* skip FMT4 / FMT5 / FMT7 labels */
                                if (f1.DS1FMTID == _ascebc['4']
                                    || f1.DS1FMTID == _ascebc['5']
                                    || f1.DS1FMTID == _ascebc['7']
                                    || f1.DS1FMTID == _ascebc['9']) {
                                        blk++;
                                        data = read_dev_sector(bdev, blk *
                                                               (blocksize/512),
                                                                &sect);
                                        continue;
                                }

                                /* only FMT1 and 8 labels valid at this point */
                                if (f1.DS1FMTID != _ascebc['1'] &&
                                    f1.DS1FMTID != _ascebc['8'])
                                        break;

                                /* OK, we got valid partition data */
                                offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
                                size  = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
                                        offset + geo->sectors;
                                if (counter >= state->limit)
                                        break;
                                put_partition(state, counter + 1,
                                              offset * (blocksize >> 9),
                                              size * (blocksize >> 9));
                                counter++;
                                blk++;
                                data = read_dev_sector(bdev,
                                                       blk * (blocksize/512),
                                                       &sect);
                        }

                        if (!data)
                                /* Are we not supposed to report this ? */
                                goto out_readerr;
                } else
                        printk(KERN_WARNING "Warning, expected Label VOL1 not "
                               "found, treating as CDL formated Disk");

        }

        printk("\n");
        goto out_freeall;


out_readerr:
        res = -1;
out_freeall:
        kfree(label);
out_nolab:
        kfree(geo);
out_nogeo:
        kfree(info);
out_exit:
        return res;
}