/*
 *      	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/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>

int           obd_print_entry = 1;
int           obd_debug_level = 4095;
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, "Refcount now %d\n", 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 "presto_psdev_release: refcount(%d) <= 0\n",
		       obd_dev[dev].obd_refcnt);
	obd_dev[dev].obd_refcnt--;

	CDEBUG(D_PSDEV, "Refcount now %d\n", 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;
	
	tmp = &obd_types;
	while ( (tmp = tmp->next) != &obd_types ) {
		type = list_entry(tmp, struct obd_type, typ_chain);
		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;

	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)
{
	int err, i_ino, dev;
	struct obd_device *obddev;
	struct oic_rw_s rw_s; /* read, write */
	long int cli_id; /* connect, disconnect */

	struct oic_prealloc_s prealloc; /* preallocate */

	if (!inode)
		return -EINVAL;

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

	switch (cmd) {
	case OBD_IOC_ATTACH: {
		struct obd_type *type;
		struct oic_attach input;

		/* 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);
			return -EINVAL;
		}

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

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

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

		CDEBUG(D_IOCTL, "Attach %d, type %s\n", 
		       dev, obddev->obd_type->typ_name);
		if (!obddev->obd_type->typ_ops || 
		    !obddev->obd_type->typ_ops->o_attach ) {
			obddev->obd_flags |=  OBD_ATTACHED;
			type->typ_refcnt++;
			MOD_INC_USE_COUNT;
			return 0;
		}

		/* do the attach */
		err = obddev->obd_type->typ_ops->o_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;
		} else {
			obddev->obd_flags |=  OBD_ATTACHED;
			type->typ_refcnt++;
			MOD_INC_USE_COUNT;
		}
		return err;
	}
	case OBD_IOC_FORMAT: {
		struct ioc_format {
			int format_datalen;
			void *format_data;
		} input;

		/* have we attached a type to this device */
		if ( !obddev->obd_type ) {
			CDEBUG(D_IOCTL, "OBD Device %d has no type.\n", dev);
			return -EINVAL;
		}

		/* get main structure */
		err = copy_from_user(&input, (void *) arg, sizeof(input));
		if (err) 
			return err;

		err = getdata(input.format_datalen, &input.format_data);
		if (err) 
			return err;

		if (!obddev->obd_type->typ_ops || 
		    !obddev->obd_type->typ_ops->o_format )
			return -EOPNOTSUPP;

		/* do the format */
		CDEBUG(D_IOCTL, "Format %d, type %s\n", dev, 
		       obddev->obd_type->typ_name);
		err = obddev->obd_type->typ_ops->o_format
			(obddev, input.format_datalen, input.format_data);

		OBD_FREE(input.format_data, input.format_datalen);
		return err;
	}
	case OBD_IOC_PARTITION: {
		struct ioc_part {
			int part_datalen;
			void *part_data;
		} input;

		/* have we attached a type to this device */
		if ( !obddev->obd_type ) {
			CDEBUG(D_IOCTL, "OBD Device %d has no type.\n", dev);
			return -EINVAL;
		}

		/* get main structure */
		err = copy_from_user(&input, (void *) arg, sizeof(input));
		if (err) 
			return err;

		err = getdata(input.part_datalen, &input.part_data);
		if (err) 
			return err;

		if (!obddev->obd_type->typ_ops || 
		    !obddev->obd_type->typ_ops->o_partition )
			return -EOPNOTSUPP;

		/* do the partition */
		CDEBUG(D_IOCTL, "Partition %d, type %s\n", dev, 
		       obddev->obd_type->typ_name);
		err = obddev->obd_type->typ_ops->o_partition
			(obddev, input.part_datalen, input.part_data);

		OBD_FREE(input.part_data, input.part_datalen);
		return err;
	}
	case OBD_IOC_SETUP_OBDDEV: {
		struct ioc_setup {
			int setup_datalen;
			void *setup_data;
		} input;

		/* have we attached a type to this device */
		if (!(obddev->obd_flags & OBD_ATTACHED)) {
			CDEBUG(D_IOCTL, "OBD Device %d has no type.\n", dev);
			return -EINVAL;
		}

		/* 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);
			return -EINVAL;
		}

		/* get main structure */
		err = copy_from_user(&input, (void *) arg, sizeof(input));
		if (err) 
			return err;

		err = getdata(input.setup_datalen, &input.setup_data);
		if (err) 
			return err;

		/* do the setup */
		CDEBUG(D_IOCTL, "Setup %d, type %s\n", dev, 
		       obddev->obd_type->typ_name);
		if ( !obddev->obd_type->typ_ops || 
		     !obddev->obd_type->typ_ops->o_setup )
			return -EOPNOTSUPP;

		err = obddev->obd_type->typ_ops->o_setup
			(obddev, input.setup_datalen, input.setup_data);

		if ( err ) 
			obddev->obd_flags &= ~OBD_SET_UP;
		else 
			obddev->obd_flags |= OBD_SET_UP;
		return err;
	}
	case OBD_IOC_CLEANUP_OBDDEV: {
		int rc;

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

		if ( !obddev->obd_type->typ_refcnt ) 
			printk("OBD_CLEANUP: refcount wrap!\n");

		if ( !obddev->obd_type->typ_ops->o_cleanup )
			goto cleanup_out;

		/* cleanup has no argument */
		rc = obddev->obd_type->typ_ops->o_cleanup(obddev);
		if ( rc )
			return rc;

	cleanup_out: 
		obddev->obd_flags = 0;
		obddev->obd_type->typ_refcnt--;
		obddev->obd_type = NULL;
		MOD_DEC_USE_COUNT;
		return 0;
	}
	case OBD_IOC_CONNECT:
	{
		struct obd_conn_info conninfo;

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

		if (obddev->obd_type->typ_ops->o_connect(obddev, &conninfo))
			return -EINVAL;

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

		get_user(cli_id, (int *) arg);

		obddev->obd_type->typ_ops->o_disconnect(cli_id);
		return 0;

	case OBD_IOC_SYNC:
		/* sync doesn't need a connection ID, because it knows
		 * what device it was called on, and can thus get the
		 * superblock that it needs. */
		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;

		if (!obddev->u.sim.sim_sb || !obddev->u.sim.sim_sb->s_dev) {
			CDEBUG(D_IOCTL, "fatal: device not initialized.\n");
			err = -EINVAL;
		} else {
			if ((err = fsync_dev(obddev->u.sim.sim_sb->s_dev)))
				CDEBUG(D_IOCTL, "sync: fsync_dev failure\n");
			else
				CDEBUG(D_IOCTL, "sync: success\n");
		}

		return put_user(err, (int *) arg);
	case OBD_IOC_CREATE:
		/* similarly, create doesn't need a connection ID for
		 * the same reasons. */

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


		if (!obddev->u.sim.sim_sb) {
			CDEBUG(D_IOCTL, "fatal: device not initialized.\n");
			return put_user(-EINVAL, (int *) arg);
		}

		i_ino = obddev->obd_type->typ_ops->o_create(obddev, 0, &err);
		if (err) {
			CDEBUG(D_IOCTL, "create: obd_inode_new failure\n");
			/* 0 is the only error value */
			return put_user(0, (int *) arg);
		}

		return put_user(i_ino, (int *) arg);
	case OBD_IOC_DESTROY:
	{
		struct destroy_s {
			unsigned int conn_id;
			unsigned int ino;
		} destroy;

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


		copy_from_user(&destroy, (int *)arg, sizeof(struct destroy_s));
		if ( !obddev->obd_type ||
		     !obddev->obd_type->typ_ops->o_destroy)
			return -EINVAL;

		return obddev->obd_type->typ_ops->o_destroy(destroy.conn_id, destroy.ino);
	}
	case OBD_IOC_SETATTR:
	{
		int err;
		struct tmp {
			unsigned int conn_id;
			unsigned long ino;
			struct iattr iattr;
		} foo;
		struct inode holder;
		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;


		err= copy_from_user(&foo, (int *)arg, sizeof(struct tmp));
		if (err)
			return err;

		if ( !obddev->obd_type ||
		     !obddev->obd_type->typ_ops->o_setattr)
			return -EINVAL;
		
		inode_setattr(&holder, &foo.iattr);
		return obddev->obd_type->typ_ops->o_setattr(foo.conn_id, foo.ino, &holder);
	}

	case OBD_IOC_GETATTR:
	{
		int err;
		struct tmp {
			unsigned int conn_id;
			unsigned long ino;
		} foo;
		struct iattr iattr;
		struct inode holder;
		copy_from_user(&foo, (int *)arg, sizeof(struct tmp));

		if ( !obddev->obd_type ||
		     !obddev->obd_type->typ_ops->o_getattr)
			return -EINVAL;

		if (obddev->obd_type->typ_ops->o_getattr(foo.conn_id, 
							 foo.ino, &holder))
			return -EINVAL;

		inode_to_iattr(&holder, &iattr);
		err = copy_to_user((int *)arg, &iattr, sizeof(iattr));
		return err;
	}

	case OBD_IOC_READ2:
	{
		int err;

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

		err = copy_from_user(&rw_s, (int *)arg, sizeof(struct oic_rw_s));
		if ( err ) 
			return err;

		if ( !obddev->obd_type->typ_ops || 
		     !obddev->obd_type->typ_ops->o_read ) 
			return -EINVAL;

		rw_s.count = obddev->obd_type->typ_ops->o_read2(rw_s.conn_id, 
				       rw_s.inode, 
				       rw_s.buf,
				       rw_s.count, 
				       rw_s.offset, 
				       &err);
		if ( err ) 
			return err;

		err = copy_to_user((int*)arg, &rw_s.count, 
				   sizeof(unsigned long));
		return err;
	}


	case OBD_IOC_READ:
	{
		int err;
		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;


		err = copy_from_user(&rw_s, (int *)arg, sizeof(struct oic_rw_s));
		if ( err ) 
			return err;

		if ( !obddev->obd_type->typ_ops || 
		     !obddev->obd_type->typ_ops->o_read ) 
			return -EINVAL;

		rw_s.count = obddev->obd_type->typ_ops->o_read(rw_s.conn_id, 
							       rw_s.inode, 
							       rw_s.buf,
							       rw_s.count, 
							       rw_s.offset, 
							       &err);
		if ( err ) 
			return err;

		err = copy_to_user((int*)arg, &rw_s.count, 
				   sizeof(unsigned long));
		return err;
	}

	case OBD_IOC_WRITE:
	{
		int err;
		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;


		copy_from_user(&rw_s, (int *)arg, sizeof(struct oic_rw_s));
		CDEBUG(D_IOCTL, "\n");
		if ( !obddev->obd_type->typ_ops->o_write ) 
			return -EINVAL;
		rw_s.count = 
			obddev->obd_type->typ_ops->o_write(rw_s.conn_id,
							   rw_s.inode, 
							   rw_s.buf,
							   rw_s.count, 
							   rw_s.offset, 
							   &err);

		printk("Result rw_s.count %ld\n", rw_s.count);
		return (int)rw_s.count;
		copy_to_user((int *)arg, &rw_s.count, 
			     sizeof(unsigned long));
		return err;
	}
	case OBD_IOC_PREALLOCATE:
		/* has this minor been registered? */
		if (!obddev->obd_type)
			return -ENODEV;


		copy_from_user(&prealloc, (int *)arg,
			       sizeof(struct oic_prealloc_s));

		if (!obddev->u.sim.sim_sb || !obddev->u.sim.sim_sb->s_dev) {
			CDEBUG(D_IOCTL, "fatal: device not initialized.\n");
			return -EINVAL;
		}

		if (!obddev->obd_type || 
		    !obddev->obd_type->typ_ops->o_preallocate)
			return -EINVAL;

		prealloc.alloc =
			obddev->obd_type->typ_ops->o_preallocate(prealloc.cli_id, prealloc.alloc,
					       prealloc.inodes, &err);
		if ( err ) 
			return err;
		return copy_to_user((int *)arg, &prealloc,
				    sizeof(struct oic_prealloc_s));
	case OBD_IOC_STATFS:
	{
		struct statfs *tmp;
		unsigned int conn_id;
		struct statfs buf;
		int rc;

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

		tmp = (void *)arg + sizeof(unsigned int);
		get_user(conn_id, (int *) arg);
		if ( !obddev->obd_type ||
		     !obddev->obd_type->typ_ops->o_statfs)
			return -EINVAL;

		rc = obddev->obd_type->typ_ops->o_statfs(conn_id, &buf);
		if ( rc ) 
			return rc;
		rc = copy_to_user(tmp, &buf, sizeof(buf));
		return rc;
		
	}
	default:
		printk("invalid ioctl: cmd = %x, arg = %lx\n", cmd, arg);
		return -ENOTTY;
	}
}

/* Driver interface done, utility functions follow */

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

	if  ( obd_nm_to_type(nm) ) {
		CDEBUG(D_IOCTL, "Type %s already registered\n", nm);
		return -1;
	}

	OBD_ALLOC(type, struct obd_type * , sizeof(*type));
	if ( !type ) 
		return -ENOMEM;
	memset(type, 0, sizeof(*type));
	INIT_LIST_HEAD(&type->typ_chain);

	list_add(&type->typ_chain, obd_types.next);
	type->typ_ops = ops;
	type->typ_name = nm;
	return 0;
}
	
int obd_unregister_type(char *nm)
{
	struct obd_type *type = obd_nm_to_type(nm);

	if ( !type ) 
		return -1;

	if ( type->typ_refcnt ) 
		return -1;

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

/* 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,                  /* check_media_change */
	NULL,                  /* revalidate */
	NULL                   /* lock */
};


/* modules setup */

int init_obd(void)
{
	int i;

	printk(KERN_INFO "OBD class driver  v0.002, braam@stelias.com\n");

	INIT_LIST_HEAD(&obd_types);

	if (register_chrdev(OBD_PSDEV_MAJOR,"obd_psdev", 
			    &obd_psdev_fops)) {
		printk(KERN_ERR "obd_psdev: 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]));
		INIT_LIST_HEAD(&obd_dev[i].u.sim.sim_clients);
	}

	obd_sysctl_init();

	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);

#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_type->typ_ops->o_cleanup_device )
			return obddev->obd_type->typ_ops->o_cleanup_device(i);
	}

	obd_sysctl_clean();
}
#endif