/*

   * 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 = state->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;

  	sector_t labelsect;

  	char tmp[64];

  	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;

  
  	/*

  	 * Special case for FBA disks: label sector does not depend on
  	 * blocksize.
  	 */
  	if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
  	    (info->cu_type == 0x3880 && info->dev_type == 0x3370))
  		labelsect = info->label_block;
  	else
  		labelsect = info->label_block * (blocksize >> 9);
  
  	/*

  	 * Get volume label, extract name and type.
  	 */

  	data = read_part_sector(state, labelsect, &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) {

  				snprintf(tmp, sizeof(tmp), "CMS1/%8s(MDSK):", name);
  				strlcat(state->pp_buf, tmp, PAGE_SIZE);

  				/* disk is reserved minidisk */

  				offset = label->cms.disk_offset;
  				size = (label->cms.block_count - 1)
  					* (blocksize >> 9);
  			} else {

  				snprintf(tmp, sizeof(tmp), "CMS1/%8s:", name);
  				strlcat(state->pp_buf, tmp, PAGE_SIZE);

  				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) {

  				snprintf(tmp, sizeof(tmp), "LNX1/%8s:", name);
  				strlcat(state->pp_buf, tmp, PAGE_SIZE);

  				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 */

  				strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);

  				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) {

  			snprintf(tmp, sizeof(tmp), "VOL1/%8s:", name);
  			strlcat(state->pp_buf, tmp, PAGE_SIZE);

  			/*
  			 * get block number and read then go through format1
  			 * labels
  			 */
  			blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
  			counter = 0;

  			data = read_part_sector(state, 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_part_sector(state,
  						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_part_sector(state,
  						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");

  	}

  	strlcat(state->pp_buf, "
  ", PAGE_SIZE);

  	goto out_freeall;

  out_readerr:

  	res = -1;
  out_freeall:

  	kfree(label);
  out_nolab:

  	kfree(geo);
  out_nogeo:
  	kfree(info);

  out_exit:
  	return res;

  }