/*
 *      	An implementation of a loadable kernel mode driver providing
 *		multiple kernel/user space bidirectional communications links.
 *
 * 		Author: 	Alan Cox <alan@cymru.net>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 * 
 *              Adapted to become the Linux 2.0 Coda pseudo device
 *              Peter  Braam  <braam@maths.ox.ac.uk> 
 *              Michael Callahan <mjc@emmy.smith.edu>           
 *
 *              Changes for Linux 2.1
 *              Copyright (c) 1997 Carnegie-Mellon University
 *
 *              Redone again for Intermezzo
 *              Copyright (c) 1998 Peter J. Braam
 *
 *              Hacked up again for simulated OBD
 *              Copyright (c) 1999 Stelias Computing, Inc.
 *                (authors {pschwan,braam}@stelias.com)
 *              Copyright (C) 1999 Seagate Technology, Inc.
 *
 * 
 */

#define EXPORT_SYMTAB

#include <linux/config.h> /* for CONFIG_PROC_FS */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/kmod.h>   /* for request_module() */
#include <linux/sched.h>
#include <linux/lp.h>
#include <linux/malloc.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/list.h>
#include <asm/io.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <asm/poll.h>
#include <asm/uaccess.h>

#include <linux/obd_support.h>
#include <linux/obd_class.h>

static int obd_init_magic;
int           obd_print_entry = 1;
int           obd_debug_level = 0;
struct obd_device obd_dev[MAX_OBD_DEVICES];
struct list_head obd_types;

/* called when opening /dev/obdNNN */
static int obd_class_open(struct inode * inode, struct file * file)
{
	int dev;
        ENTRY;

	if (!inode)
		return -EINVAL;
	dev = MINOR(inode->i_rdev);
	if (dev >= MAX_OBD_DEVICES)
		return -ENODEV;
	obd_dev[dev].obd_refcnt++;
	CDEBUG(D_PSDEV, "Dev %d refcount now %d\n", dev,
	       obd_dev[dev].obd_refcnt);

        MOD_INC_USE_COUNT;
        EXIT;
        return 0;
}

/* called when closing /dev/obdNNN */
static int obd_class_release(struct inode * inode, struct file * file)
{
	int dev;
        ENTRY;

	if (!inode)
		return -EINVAL;
	dev = MINOR(inode->i_rdev);
	if (dev >= MAX_OBD_DEVICES)
		return -ENODEV;
	fsync_dev(inode->i_rdev);
	if (obd_dev[dev].obd_refcnt <= 0)
		printk(KERN_ALERT __FUNCTION__ ": refcount(%d) <= 0\n",
		       obd_dev[dev].obd_refcnt);
	obd_dev[dev].obd_refcnt--;

	CDEBUG(D_PSDEV, "Dev %d refcount now %d\n", dev,
	       obd_dev[dev].obd_refcnt);
        MOD_DEC_USE_COUNT;

        EXIT;
        return 0;
}

/* support function */
static struct obd_type *obd_nm_to_type(char *nm) 
{
	struct list_head *tmp;
	struct obd_type *type;
	CDEBUG(D_IOCTL, "SEARCH %s\n", nm);
	
	tmp = &obd_types;
	while ( (tmp = tmp->next) != &obd_types ) {
		type = list_entry(tmp, struct obd_type, typ_chain);
		CDEBUG(D_IOCTL, "TYP %s\n", type->typ_name);
		if (strlen(type->typ_name) == strlen(nm) &&
		    strcmp(type->typ_name, nm) == 0 ) {
			return type;
		}
	}
	return NULL;
}


static int getdata(int len, void **data)
{
	void *tmp = NULL;

	if (!len) 
		return 0;

	CDEBUG(D_IOCTL, "getdata: len %d, add %p\n", len, *data);

	OBD_ALLOC(tmp, void *, len);
	if ( !tmp )
		return -ENOMEM;
	
	memset(tmp, 0, len);
	if ( copy_from_user(tmp, *data, len)) {
		OBD_FREE(tmp,len);
		return -EFAULT;
	}
	*data = tmp;

	return 0;
}

/* to control /dev/obdNNN */
static int obd_class_ioctl (struct inode * inode, struct file * filp, 
			    unsigned int cmd, unsigned long arg)
{
	struct obd_device *obddev;
	/* NOTE this must be larger than any of the ioctl data structs */
	char buf[1024];
	void *tmp_buf = buf;
	struct obd_conn conn;
	int err, dev;
	long int cli_id; /* connect, disconnect */

	if (!inode)
		return -EINVAL;

	dev = MINOR(inode->i_rdev);
	if (dev > MAX_OBD_DEVICES)
		return -ENODEV;
	obddev = &obd_dev[dev];
	conn.oc_dev = obddev;

	switch (cmd) {
	case TCGETS:
		return -EINVAL;
	case OBD_IOC_ATTACH: {
		struct obd_type *type;
		struct oic_generic *input = tmp_buf;
		char *nm;

		ENTRY;
		/* have we attached a type to this device */
		if ( obddev->obd_type || 
		     (obddev->obd_flags & OBD_ATTACHED) ){
			CDEBUG(D_IOCTL,
			       "OBD Device %d already attached to type %s.\n",
			       dev, obddev->obd_type->typ_name);
			EXIT;
			return -EBUSY;
		}

		/* get data structures */
		err = copy_from_user(input, (void *)arg, sizeof(*input));
		if ( err ) {
			EXIT;
			return err;
		}

		err = getdata(input->att_typelen + 1, &input->att_type);
		if ( err ) {
			EXIT;
			return err;
		}

		/* find the type */
		nm = input->att_type;
		type = obd_nm_to_type(nm);
#ifdef CONFIG_KMOD
		if ( !type ) {
			if ( !request_module(nm) ) {
				CDEBUG(D_IOCTL, "Loaded module '%s'\n", nm);
				type = obd_nm_to_type(nm);
			} else {
				CDEBUG(D_IOCTL, "Can't load module '%s'\n", nm);
			}
		}
#endif

		OBD_FREE(input->att_type, input->att_typelen + 1);
		if ( !type ) {
			printk(__FUNCTION__ ": unknown obd type dev %d\n",
			       dev);
			EXIT;
			return -EINVAL;
		}
		obddev->obd_type = type;
		
		/* get the attach data */
		err = getdata(input->att_datalen, &input->att_data);
		if ( err ) {
			EXIT;
			return err;
		}

		INIT_LIST_HEAD(&obddev->obd_gen_clients);
		obddev->obd_multi_count = 0;

		CDEBUG(D_IOCTL, "Attach %d, datalen %d, type %s\n", 
		       dev, input->att_datalen, obddev->obd_type->typ_name);
		/* maybe we are done */
		if ( !OBT(obddev) || !OBP(obddev, attach) ) {
			obddev->obd_flags |=  OBD_ATTACHED;
			type->typ_refcnt++;
			CDEBUG(D_IOCTL, "Dev %d refcount now %d\n", dev,
			       type->typ_refcnt);
			MOD_INC_USE_COUNT;
			EXIT;
			return 0;
		}

		/* do the attach */
		err = OBP(obddev, attach)(obddev, input->att_datalen,
					  input->att_data);
		OBD_FREE(input->att_data, input->att_datalen);

		if ( err ) {
			obddev->obd_flags &= ~OBD_ATTACHED;
			obddev->obd_type = NULL;
			EXIT;
		} else {
			obddev->obd_flags |=  OBD_ATTACHED;
			type->typ_refcnt++;
			CDEBUG(D_IOCTL, "Dev %d refcount now %d\n", dev,
			       type->typ_refcnt);
			MOD_INC_USE_COUNT;
			EXIT;
		}
		return err;
	}

	case OBD_IOC_DETACH: {

		ENTRY;
		if (obddev->obd_flags & OBD_SET_UP) {
			EXIT;
			return -EBUSY;
		}
		if (! (obddev->obd_flags & OBD_ATTACHED) ) {
			CDEBUG(D_IOCTL, "Device not attached\n");
			EXIT;
			return -ENODEV;
		}
		if ( !list_empty(&obddev->obd_gen_clients) ) {
			CDEBUG(D_IOCTL, "Device has connected clients\n");
			EXIT;
			return -EBUSY;
		}

		CDEBUG(D_IOCTL, "Detach %d, type %s\n", dev,
		       obddev->obd_type->typ_name);
		obddev->obd_flags &= ~OBD_ATTACHED;
		obddev->obd_type->typ_refcnt--;
		CDEBUG(D_IOCTL, "Dev %d refcount now %d\n", dev,
		       obddev->obd_type->typ_refcnt);
		obddev->obd_type = NULL;
		MOD_DEC_USE_COUNT;
		EXIT;
		return 0;
	}

	case OBD_IOC_SETUP: {
		struct ioc_setup {
			int setup_datalen;
			void *setup_data;
		} *setup;
		setup = tmp_buf;

		ENTRY;
		/* have we attached a type to this device */
		if (!(obddev->obd_flags & OBD_ATTACHED)) {
			CDEBUG(D_IOCTL, "Device not attached\n");
			EXIT;
			return -ENODEV;
		}

		/* has this been done already? */
		if ( obddev->obd_flags & OBD_SET_UP ) {
			CDEBUG(D_IOCTL, "Device %d already setup (type %s)\n",
			       dev, obddev->obd_type->typ_name);
			EXIT;
			return -EBUSY;
		}

		/* get main structure */
		err = copy_from_user(setup, (void *) arg, sizeof(*setup));
		if (err) {
			EXIT;
			return err;
		}

		err = getdata(setup->setup_datalen, &setup->setup_data);
		if (err) {
			EXIT;
			return err;
		}

		/* do the setup */
		CDEBUG(D_IOCTL, "Setup %d, type %s\n", dev, 
		       obddev->obd_type->typ_name);
		if ( !OBT(obddev) || !OBP(obddev, setup) ) {
			obddev->obd_type->typ_refcnt++;
			CDEBUG(D_IOCTL, "Dev %d refcount now %d\n",
			       dev, obddev->obd_type->typ_refcnt);
			obddev->obd_flags |= OBD_SET_UP;
			EXIT;
			return 0;
		}

		err = OBP(obddev, setup)(obddev, setup->setup_datalen,
					 setup->setup_data);

		if ( err )  {
			obddev->obd_flags &= ~OBD_SET_UP;
			EXIT;
		} else {
			obddev->obd_type->typ_refcnt++;
			CDEBUG(D_IOCTL, "Dev %d refcount now %d\n",
			       dev, obddev->obd_type->typ_refcnt);
			obddev->obd_flags |= OBD_SET_UP;
			EXIT;
		}
		return err;
	}
	case OBD_IOC_CLEANUP: {
		ENTRY;
		/* has this minor been registered? */
		if (!obddev->obd_type) {
			CDEBUG(D_IOCTL, "OBD Device %d has no type.\n", dev);
			EXIT;
			return -ENODEV;
		}

		if ( !obddev->obd_type->typ_refcnt ) {
			CDEBUG(D_IOCTL, "dev %d has refcount (%d)!\n",
			       dev, obddev->obd_type->typ_refcnt);
			EXIT;
			return -EBUSY;
		}

		if ( (!(obddev->obd_flags & OBD_SET_UP)) ||
		     (!(obddev->obd_flags & OBD_ATTACHED))) {
			CDEBUG(D_IOCTL, "device not attached or set up\n");
			EXIT;
			return -ENODEV;
		}

		if ( !OBT(obddev) || !OBP(obddev, cleanup) )
			goto cleanup_out;

		/* cleanup has no argument */
		err = OBP(obddev, cleanup)(obddev);
		if ( err ) {
			EXIT;
			return err;
		}

	cleanup_out: 
		obddev->obd_flags &= ~OBD_SET_UP;
		obddev->obd_type->typ_refcnt--;
		CDEBUG(D_IOCTL, "Dev %d refcount now %d\n", dev,
		       obddev->obd_type->typ_refcnt);
		EXIT;
		return 0;
	}
	case OBD_IOC_CONNECT:
	{
		if ( (!(obddev->obd_flags & OBD_SET_UP)) ||
		     (!(obddev->obd_flags & OBD_ATTACHED))) {
			CDEBUG(D_IOCTL, "Device not attached or set up\n");
			return -ENODEV;
		}

		if ( !OBT(obddev) || !OBP(obddev, connect) )
			return -EOPNOTSUPP;
		
		err = OBP(obddev, connect)(&conn);
		if ( err )
			return err;

		return copy_to_user((int *)arg, &conn.oc_id,
				    sizeof(uint32_t));
	}
	case OBD_IOC_DISCONNECT:
		/* frees data structures */
		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;

		get_user(cli_id, (int *) arg);
		conn.oc_id = cli_id;

		if ( !OBT(obddev) || !OBP(obddev, disconnect))
			return -EOPNOTSUPP;
		
		OBP(obddev, disconnect)(&conn);
		return 0;

	case OBD_IOC_SYNC: {
		struct oic_range_s *range = tmp_buf;

		if (!obddev->obd_type)
			return -ENODEV;

		err = copy_from_user(range, (const void *)arg,  sizeof(*range));

		if ( err ) {
			EXIT;
			return err;
		}
			
		if ( !OBT(obddev) || !OBP(obddev, sync) ) {
			err = -EOPNOTSUPP;
			EXIT;
			return err;
		}

		/* XXX sync needs to be tested/verified */
		err = OBP(obddev, sync)(&conn, &range->obdo, range->count,
					range->offset);

		if ( err ) {
			EXIT;
			return err;
		}
			
		return put_user(err, (int *) arg);
	}
	case OBD_IOC_CREATE: {
		struct oic_attr_s *attr = tmp_buf;

		err = copy_from_user(attr, (const void *)arg,  sizeof(*attr));
		if (err) {
			EXIT;
			return err;
		}

		/* has this minor been registered? */
		if ( !(obddev->obd_flags & OBD_ATTACHED) ||
		     !(obddev->obd_flags & OBD_SET_UP)) {
			CDEBUG(D_IOCTL, "Device not attached or set up\n");
			return -ENODEV;
		}
		conn.oc_id = attr->conn_id;

		if ( !OBT(obddev) || !OBP(obddev, create) )
			return -EOPNOTSUPP;

		err = OBP(obddev, create)(&conn, &attr->obdo);
		if (err) {
			EXIT;
			return err;
		}

		err = copy_to_user((int *)arg, attr, sizeof(*attr));
		EXIT;
		return err;
	}

	case OBD_IOC_DESTROY: {
		struct oic_attr_s *attr = tmp_buf;
		
		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;

		err = copy_from_user(attr, (int *)arg, sizeof(*attr));
		if ( err ) {
			EXIT;
			return err;
		}

		if ( !OBT(obddev) || !OBP(obddev, destroy) )
			return -EOPNOTSUPP;

		conn.oc_id = attr->conn_id;
		err = OBP(obddev, destroy)(&conn, &attr->obdo);
		EXIT;
		return err;
	}

	case OBD_IOC_SETATTR: {
		struct oic_attr_s *attr = tmp_buf;

		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;

		err = copy_from_user(attr, (int *)arg, sizeof(*attr));
		if (err)
			return err;

		if ( !OBT(obddev) || !OBP(obddev, setattr) )
			return -EOPNOTSUPP;
		
		conn.oc_id = attr->conn_id;
		err = OBP(obddev, setattr)(&conn, &attr->obdo);
		EXIT;
		return err;
	}

	case OBD_IOC_GETATTR: {
		struct oic_attr_s *attr = tmp_buf;

		err = copy_from_user(attr, (int *)arg, sizeof(*attr));
		if (err)
			return err;

		conn.oc_id = attr->conn_id;
		ODEBUG(&attr->obdo);
		err = OBP(obddev, getattr)(&conn, &attr->obdo);
		if ( err ) {
			EXIT;
			return err;
		}

		err = copy_to_user((int *)arg, attr, sizeof(*attr));
		EXIT;
		return err;
	}

	case OBD_IOC_READ: {
		int err;
		struct oic_rw_s *rw_s = tmp_buf;  /* read, write ioctl str */

		err = copy_from_user(rw_s, (int *)arg, sizeof(*rw_s));
		if ( err ) {
			EXIT;
			return err;
		}

		conn.oc_id = rw_s->conn_id;

		if ( !OBT(obddev) || !OBP(obddev, read) ) {
			err = -EOPNOTSUPP;
			EXIT;
			return err;
		}


		err = OBP(obddev, read)(&conn, &rw_s->obdo, rw_s->buf, 
					&rw_s->count, rw_s->offset);
		
		ODEBUG(&rw_s->obdo);
		CDEBUG(D_INODE, "READ: conn %d, count %Ld, offset %Ld, '%s'\n",
		       rw_s->conn_id, rw_s->count, rw_s->offset, rw_s->buf);
		if ( err ) {
			EXIT;
			return err;
		}
			
		err = copy_to_user((int*)arg, &rw_s->count, sizeof(rw_s->count));
		EXIT;
		return err;
	}

	case OBD_IOC_WRITE: {
		struct oic_rw_s *rw_s = tmp_buf;  /* read, write ioctl str */

		err = copy_from_user(rw_s, (int *)arg, sizeof(*rw_s));
		if ( err ) {
			EXIT;
			return err;
		}

		conn.oc_id = rw_s->conn_id;

		if ( !OBT(obddev) || !OBP(obddev, write) ) {
			err = -EOPNOTSUPP;
			return err;
		}

		CDEBUG(D_INODE, "WRITE: conn %d, count %Ld, offset %Ld, '%s'\n",
		       rw_s->conn_id, rw_s->count, rw_s->offset, rw_s->buf);
		err = OBP(obddev, write)(&conn, &rw_s->obdo, rw_s->buf, 
					 &rw_s->count, rw_s->offset);
		ODEBUG(&rw_s->obdo);
		if ( err ) {
			EXIT;
			return err;
		}

		err = copy_to_user((int *)arg, &rw_s->count,
				   sizeof(rw_s->count));
		EXIT;
		return err;
	}
	case OBD_IOC_PREALLOCATE: {
		struct oic_prealloc_s *prealloc = tmp_buf;

		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;

		err = copy_from_user(prealloc, (int *)arg, sizeof(*prealloc));
		if (err) 
			return -EFAULT;

		if ( !(obddev->obd_flags & OBD_ATTACHED) ||
		     !(obddev->obd_flags & OBD_SET_UP)) {
			CDEBUG(D_IOCTL, "Device not attached or set up\n");
			return -ENODEV;
		}

		if ( !OBT(obddev) || !OBP(obddev, preallocate) )
			return -EOPNOTSUPP;

		conn.oc_id = prealloc->conn_id;
		err = OBP(obddev, preallocate)(&conn, &prealloc->alloc,
					       prealloc->ids);
		if ( err ) {
			EXIT;
			return err;
		}

		err =copy_to_user((int *)arg, prealloc, sizeof(*prealloc));
		EXIT;
		return err;
	}
	case OBD_IOC_STATFS: {
		struct statfs *tmp;
		unsigned int conn_id;
		struct statfs buf;

		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;

		tmp = (void *)arg + sizeof(unsigned int);
		get_user(conn_id, (int *) arg);

		if ( !OBT(obddev) || !OBP(obddev, statfs) )
			return -EOPNOTSUPP;

		conn.oc_id = conn_id;
		err = OBP(obddev, statfs)(&conn, &buf);
		if ( err ) {
			EXIT;
			return err;
		}
		err = copy_to_user(tmp, &buf, sizeof(buf));
		EXIT;
		return err;
		
	}
	case OBD_IOC_COPY: {
		struct ioc_mv_s *mvdata = tmp_buf;

		if ( (!(obddev->obd_flags & OBD_SET_UP)) ||
		     (!(obddev->obd_flags & OBD_ATTACHED))) {
			CDEBUG(D_IOCTL, "Device not attached or set up\n");
			return -ENODEV;
		}

		/* get main structure */
		err = copy_from_user(mvdata, (void *) arg, sizeof(*mvdata));
		if (err) {
			EXIT;
			return err;
		}

		if ( !OBT(obddev) || !OBP(obddev, copy) )
			return -EOPNOTSUPP;

		/* do the partition */
		CDEBUG(D_IOCTL, "Copy %d, type %s dst %Ld src %Ld\n", dev, 
		       obddev->obd_type->typ_name, mvdata->dst.o_id, 
		       mvdata->src.o_id);

		conn.oc_id = mvdata->src_conn_id;

		err = OBP(obddev, copy)(&conn, &mvdata->dst, 
					&conn, &mvdata->src, 
					mvdata->src.o_size, 0);
		return err;
	}

	case OBD_IOC_MIGR: {
		struct ioc_mv_s *mvdata = tmp_buf;

		if ( (!(obddev->obd_flags & OBD_SET_UP)) ||
		     (!(obddev->obd_flags & OBD_ATTACHED))) {
			CDEBUG(D_IOCTL, "Device not attached or set up\n");
			return -ENODEV;
		}

		err = copy_from_user(mvdata, (void *) arg, sizeof(*mvdata));
		if (err) {
			EXIT;
			return err;
		}

		CDEBUG(D_IOCTL, "Migrate copying %d bytes\n", sizeof(*mvdata));

		if ( !OBT(obddev) || !OBP(obddev, migrate) )
			return -EOPNOTSUPP;

		/* do the partition */
		CDEBUG(D_IOCTL, "Migrate %d, type %s conn %d src %Ld dst %Ld\n",
		       dev, obddev->obd_type->typ_name, mvdata->src_conn_id,
		       mvdata->src.o_id, mvdata->dst.o_id);

		conn.oc_id = mvdata->src_conn_id;
		err = OBP(obddev, migrate)(&conn, &mvdata->dst, &mvdata->src, 
					   mvdata->src.o_size, 0);

		return err;
	}

	default: {
		struct obd_type *type;
		struct oic_generic input;
		char *nm;
		void *karg;

		/* get data structures */
		err = copy_from_user(&input, (void *)arg, sizeof(input));
		if ( err ) {
			EXIT;
			return err;
		}

		err = getdata(input.att_typelen + 1, &input.att_type);
		if ( err ) {
			EXIT;
			return err;
		}

		/* find the type */
		nm = input.att_type;
		type = obd_nm_to_type(nm);
#ifdef CONFIG_KMOD
		if ( !type ) {
			if ( !request_module(nm) ) {
				CDEBUG(D_IOCTL, "Loaded module '%s'\n", nm);
				type = obd_nm_to_type(nm);
			} else {
				CDEBUG(D_IOCTL, "Can't load module '%s'\n", nm);
			}
		}
#endif
		OBD_FREE(input.att_type, input.att_typelen + 1);
		if ( !type ) {
			printk(__FUNCTION__ ": unknown obd type dev %d\n", dev);
			EXIT;
			return -EINVAL;
		}
		
		if ( !type->typ_ops || !type->typ_ops->o_iocontrol ) {
			EXIT;
			return -EOPNOTSUPP;
		}
		conn.oc_id = input.att_connid;
		
		CDEBUG(D_IOCTL, "Calling ioctl %x for type %s, len %d\n",
		       cmd, type->typ_name, input.att_datalen);

		/* get the generic data */
		karg = input.att_data;
		err = getdata(input.att_datalen, &karg);
		if ( err ) {
			EXIT;
			return err;
		}

		err = type->typ_ops->o_iocontrol(cmd, &conn, input.att_datalen, 
						 karg, input.att_data);
		OBD_FREE(karg, input.att_datalen);

		EXIT;
		return err;
	}
	}
} /* obd_class_ioctl */

/* Driver interface done, utility functions follow */

int obd_register_type(struct obd_ops *ops, char *nm)
{
	struct obd_type *type;


	if (obd_init_magic != 0x11223344) {
		EXIT;
		return -EINVAL;
	}

	if  ( obd_nm_to_type(nm) ) {
		CDEBUG(D_IOCTL, "Type %s already registered\n", nm);
		EXIT;
		return -EEXIST;
	}
	
	OBD_ALLOC(type, struct obd_type * , sizeof(*type));
	if ( !type ) {
		EXIT;
		return -ENOMEM;
	}
	memset(type, 0, sizeof(*type));
	INIT_LIST_HEAD(&type->typ_chain);
	MOD_INC_USE_COUNT;
	list_add(&type->typ_chain, obd_types.next);
	type->typ_ops = ops;
	type->typ_name = nm;
	EXIT;
	return 0;
}
	
int obd_unregister_type(char *nm)
{
	struct obd_type *type = obd_nm_to_type(nm);

	if ( !type ) {
		MOD_DEC_USE_COUNT;
		printk(KERN_INFO __FUNCTION__ ": unknown obd type\n");
		EXIT;
		return -EINVAL;
	}

	if ( type->typ_refcnt ) {
		MOD_DEC_USE_COUNT;
		printk(KERN_ALERT __FUNCTION__ ":type %s has refcount "
		       "(%d)\n", nm, type->typ_refcnt);
		EXIT;
		return -EBUSY;
	}

	list_del(&type->typ_chain);
	OBD_FREE(type, sizeof(*type));
	MOD_DEC_USE_COUNT;
	return 0;
} /* obd_unregister_type */

/* declare character device */
static struct file_operations obd_psdev_fops = {
	NULL,                  /* llseek */
	NULL,                  /* read */
	NULL,                  /* write */
	NULL,		       /* presto_psdev_readdir */
        NULL,                  /* poll */
	obd_class_ioctl,       /* ioctl */
	NULL,		       /* presto_psdev_mmap */
	obd_class_open,        /* open */
	NULL,
	obd_class_release,     /* release */
	NULL,                  /* fsync */
	NULL,                  /* fasync */
	NULL                   /* lock */
};


/* modules setup */

int init_obd(void)
{
	int err;
	int i;

	printk(KERN_INFO "OBD class driver  v0.01, braam@stelias.com\n");
	
	INIT_LIST_HEAD(&obd_types);
	
	if (register_chrdev(OBD_PSDEV_MAJOR,"obd_psdev", 
			    &obd_psdev_fops)) {
		printk(KERN_ERR __FUNCTION__ ": unable to get major %d\n", 
		       OBD_PSDEV_MAJOR);
		return -EIO;
	}

	for (i = 0; i < MAX_OBD_DEVICES; i++) {
		memset(&(obd_dev[i]), 0, sizeof(obd_dev[i]));
		obd_dev[i].obd_minor = i;
		INIT_LIST_HEAD(&obd_dev[i].obd_gen_clients);
	}

	err = obd_init_obdo_cache();
	if (err)
		return err;
	obd_sysctl_init();
	obd_init_magic = 0x11223344;
	return 0;
}

EXPORT_SYMBOL(obd_register_type);
EXPORT_SYMBOL(obd_unregister_type);

EXPORT_SYMBOL(obd_print_entry);
EXPORT_SYMBOL(obd_debug_level);
EXPORT_SYMBOL(obd_dev);

EXPORT_SYMBOL(gen_connect);
EXPORT_SYMBOL(gen_client);
EXPORT_SYMBOL(gen_cleanup);
EXPORT_SYMBOL(gen_disconnect);
EXPORT_SYMBOL(gen_copy_data); 
EXPORT_SYMBOL(obdo_cachep);

/* EXPORT_SYMBOL(gen_multi_attach); */
EXPORT_SYMBOL(gen_multi_setup);
EXPORT_SYMBOL(gen_multi_cleanup);


#ifdef MODULE
int init_module(void)
{
	return init_obd();
}

void cleanup_module(void)
{
	int i;
        ENTRY;

        unregister_chrdev(OBD_PSDEV_MAJOR, "obd_psdev");
	for (i = 0; i < MAX_OBD_DEVICES; i++) {
		struct obd_device *obddev = &obd_dev[i];
		if ( obddev->obd_type && 
		     (obddev->obd_flags & OBD_SET_UP) &&
		     OBT(obddev) && OBP(obddev, detach) ) {
			/* XXX should this call generic detach otherwise? */
			OBP(obddev, detach)(obddev);
		} 
	}

	obd_cleanup_obdo_cache();
	obd_sysctl_clean();
	obd_init_magic = 0;
	EXIT;
}
#endif