[net-next-2.6.git] / drivers / s390 / char / tape_char.c

/*
 *  drivers/s390/char/tape_char.c
 *    character device frontend for tape device driver
 *
 *  S390 and zSeries version
 *    Copyright IBM Corp. 2001,2006
 *    Author(s): Carsten Otte <cotte@de.ibm.com>
 *		 Michael Holzheu <holzheu@de.ibm.com>
 *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/mtio.h>
#include <linux/smp_lock.h>

#include <asm/uaccess.h>

#define TAPE_DBF_AREA	tape_core_dbf

#include "tape.h"
#include "tape_std.h"
#include "tape_class.h"

#define TAPECHAR_MAJOR		0	/* get dynamic major */

/*
 * file operation structure for tape character frontend
 */
static ssize_t tapechar_read(struct file *, char __user *, size_t, loff_t *);
static ssize_t tapechar_write(struct file *, const char __user *, size_t, loff_t *);
static int tapechar_open(struct inode *,struct file *);
static int tapechar_release(struct inode *,struct file *);
static int tapechar_ioctl(struct inode *, struct file *, unsigned int,
			  unsigned long);
static long tapechar_compat_ioctl(struct file *, unsigned int,
			  unsigned long);

static const struct file_operations tape_fops =
{
	.owner = THIS_MODULE,
	.read = tapechar_read,
	.write = tapechar_write,
	.ioctl = tapechar_ioctl,
	.compat_ioctl = tapechar_compat_ioctl,
	.open = tapechar_open,
	.release = tapechar_release,
};

static int tapechar_major = TAPECHAR_MAJOR;

/*
 * This function is called for every new tapedevice
 */
int
tapechar_setup_device(struct tape_device * device)
{
	char	device_name[20];

	sprintf(device_name, "ntibm%i", device->first_minor / 2);
	device->nt = register_tape_dev(
		&device->cdev->dev,
		MKDEV(tapechar_major, device->first_minor),
		&tape_fops,
		device_name,
		"non-rewinding"
	);
	device_name[0] = 'r';
	device->rt = register_tape_dev(
		&device->cdev->dev,
		MKDEV(tapechar_major, device->first_minor + 1),
		&tape_fops,
		device_name,
		"rewinding"
	);

	return 0;
}

void
tapechar_cleanup_device(struct tape_device *device)
{
	unregister_tape_dev(&device->cdev->dev, device->rt);
	device->rt = NULL;
	unregister_tape_dev(&device->cdev->dev, device->nt);
	device->nt = NULL;
}

static int
tapechar_check_idalbuffer(struct tape_device *device, size_t block_size)
{
	struct idal_buffer *new;

	if (device->char_data.idal_buf != NULL &&
	    device->char_data.idal_buf->size == block_size)
		return 0;

	if (block_size > MAX_BLOCKSIZE) {
		DBF_EVENT(3, "Invalid blocksize (%zd > %d)\n",
			block_size, MAX_BLOCKSIZE);
		return -EINVAL;
	}

	/* The current idal buffer is not correct. Allocate a new one. */
	new = idal_buffer_alloc(block_size, 0);
	if (IS_ERR(new))
		return -ENOMEM;

	if (device->char_data.idal_buf != NULL)
		idal_buffer_free(device->char_data.idal_buf);

	device->char_data.idal_buf = new;

	return 0;
}

/*
 * Tape device read function
 */
static ssize_t
tapechar_read(struct file *filp, char __user *data, size_t count, loff_t *ppos)
{
	struct tape_device *device;
	struct tape_request *request;
	size_t block_size;
	int rc;

	DBF_EVENT(6, "TCHAR:read\n");
	device = (struct tape_device *) filp->private_data;

	/*
	 * If the tape isn't terminated yet, do it now. And since we then
	 * are at the end of the tape there wouldn't be anything to read
	 * anyways. So we return immediatly.
	 */
	if(device->required_tapemarks) {
		return tape_std_terminate_write(device);
	}

	/* Find out block size to use */
	if (device->char_data.block_size != 0) {
		if (count < device->char_data.block_size) {
			DBF_EVENT(3, "TCHAR:read smaller than block "
				  "size was requested\n");
			return -EINVAL;
		}
		block_size = device->char_data.block_size;
	} else {
		block_size = count;
	}

	rc = tapechar_check_idalbuffer(device, block_size);
	if (rc)
		return rc;

#ifdef CONFIG_S390_TAPE_BLOCK
	/* Changes position. */
	device->blk_data.medium_changed = 1;
#endif

	DBF_EVENT(6, "TCHAR:nbytes: %lx\n", block_size);
	/* Let the discipline build the ccw chain. */
	request = device->discipline->read_block(device, block_size);
	if (IS_ERR(request))
		return PTR_ERR(request);
	/* Execute it. */
	rc = tape_do_io(device, request);
	if (rc == 0) {
		rc = block_size - request->rescnt;
		DBF_EVENT(6, "TCHAR:rbytes:  %x\n", rc);
		/* Copy data from idal buffer to user space. */
		if (idal_buffer_to_user(device->char_data.idal_buf,
					data, rc) != 0)
			rc = -EFAULT;
	}
	tape_free_request(request);
	return rc;
}

/*
 * Tape device write function
 */
static ssize_t
tapechar_write(struct file *filp, const char __user *data, size_t count, loff_t *ppos)
{
	struct tape_device *device;
	struct tape_request *request;
	size_t block_size;
	size_t written;
	int nblocks;
	int i, rc;

	DBF_EVENT(6, "TCHAR:write\n");
	device = (struct tape_device *) filp->private_data;
	/* Find out block size and number of blocks */
	if (device->char_data.block_size != 0) {
		if (count < device->char_data.block_size) {
			DBF_EVENT(3, "TCHAR:write smaller than block "
				  "size was requested\n");
			return -EINVAL;
		}
		block_size = device->char_data.block_size;
		nblocks = count / block_size;
	} else {
		block_size = count;
		nblocks = 1;
	}

	rc = tapechar_check_idalbuffer(device, block_size);
	if (rc)
		return rc;

#ifdef CONFIG_S390_TAPE_BLOCK
	/* Changes position. */
	device->blk_data.medium_changed = 1;
#endif

	DBF_EVENT(6,"TCHAR:nbytes: %lx\n", block_size);
	DBF_EVENT(6, "TCHAR:nblocks: %x\n", nblocks);
	/* Let the discipline build the ccw chain. */
	request = device->discipline->write_block(device, block_size);
	if (IS_ERR(request))
		return PTR_ERR(request);
	rc = 0;
	written = 0;
	for (i = 0; i < nblocks; i++) {
		/* Copy data from user space to idal buffer. */
		if (idal_buffer_from_user(device->char_data.idal_buf,
					  data, block_size)) {
			rc = -EFAULT;
			break;
		}
		rc = tape_do_io(device, request);
		if (rc)
			break;
		DBF_EVENT(6, "TCHAR:wbytes: %lx\n",
			  block_size - request->rescnt);
		written += block_size - request->rescnt;
		if (request->rescnt != 0)
			break;
		data += block_size;
	}
	tape_free_request(request);
	if (rc == -ENOSPC) {
		/*
		 * Ok, the device has no more space. It has NOT written
		 * the block.
		 */
		if (device->discipline->process_eov)
			device->discipline->process_eov(device);
		if (written > 0)
			rc = 0;

	}

	/*
	 * After doing a write we always need two tapemarks to correctly
	 * terminate the tape (one to terminate the file, the second to
	 * flag the end of recorded data.
	 * Since process_eov positions the tape in front of the written
	 * tapemark it doesn't hurt to write two marks again.
	 */
	if (!rc)
		device->required_tapemarks = 2;

	return rc ? rc : written;
}

/*
 * Character frontend tape device open function.
 */
static int
tapechar_open (struct inode *inode, struct file *filp)
{
	struct tape_device *device;
	int minor, rc;

	DBF_EVENT(6, "TCHAR:open: %i:%i\n",
		imajor(filp->f_path.dentry->d_inode),
		iminor(filp->f_path.dentry->d_inode));

	if (imajor(filp->f_path.dentry->d_inode) != tapechar_major)
		return -ENODEV;

	lock_kernel();
	minor = iminor(filp->f_path.dentry->d_inode);
	device = tape_find_device(minor / TAPE_MINORS_PER_DEV);
	if (IS_ERR(device)) {
		DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n");
		rc = PTR_ERR(device);
		goto out;
	}


	rc = tape_open(device);
	if (rc == 0) {
		filp->private_data = device;
		rc = nonseekable_open(inode, filp);
	}
	else
		tape_put_device(device);

out:
	unlock_kernel();
	return rc;
}

/*
 * Character frontend tape device release function.
 */

static int
tapechar_release(struct inode *inode, struct file *filp)
{
	struct tape_device *device;

	DBF_EVENT(6, "TCHAR:release: %x\n", iminor(inode));
	device = (struct tape_device *) filp->private_data;

	/*
	 * If this is the rewinding tape minor then rewind. In that case we
	 * write all required tapemarks. Otherwise only one to terminate the
	 * file.
	 */
	if ((iminor(inode) & 1) != 0) {
		if (device->required_tapemarks)
			tape_std_terminate_write(device);
		tape_mtop(device, MTREW, 1);
	} else {
		if (device->required_tapemarks > 1) {
			if (tape_mtop(device, MTWEOF, 1) == 0)
				device->required_tapemarks--;
		}
	}

	if (device->char_data.idal_buf != NULL) {
		idal_buffer_free(device->char_data.idal_buf);
		device->char_data.idal_buf = NULL;
	}
	tape_release(device);
	filp->private_data = NULL;
	tape_put_device(device);

	return 0;
}

/*
 * Tape device io controls.
 */
static int
tapechar_ioctl(struct inode *inp, struct file *filp,
	       unsigned int no, unsigned long data)
{
	struct tape_device *device;
	int rc;

	DBF_EVENT(6, "TCHAR:ioct\n");

	device = (struct tape_device *) filp->private_data;

	if (no == MTIOCTOP) {
		struct mtop op;

		if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0)
			return -EFAULT;
		if (op.mt_count < 0)
			return -EINVAL;

		/*
		 * Operations that change tape position should write final
		 * tapemarks.
		 */
		switch (op.mt_op) {
			case MTFSF:
			case MTBSF:
			case MTFSR:
			case MTBSR:
			case MTREW:
			case MTOFFL:
			case MTEOM:
			case MTRETEN:
			case MTBSFM:
			case MTFSFM:
			case MTSEEK:
#ifdef CONFIG_S390_TAPE_BLOCK
				device->blk_data.medium_changed = 1;
#endif
				if (device->required_tapemarks)
					tape_std_terminate_write(device);
			default:
				;
		}
		rc = tape_mtop(device, op.mt_op, op.mt_count);

		if (op.mt_op == MTWEOF && rc == 0) {
			if (op.mt_count > device->required_tapemarks)
				device->required_tapemarks = 0;
			else
				device->required_tapemarks -= op.mt_count;
		}
		return rc;
	}
	if (no == MTIOCPOS) {
		/* MTIOCPOS: query the tape position. */
		struct mtpos pos;

		rc = tape_mtop(device, MTTELL, 1);
		if (rc < 0)
			return rc;
		pos.mt_blkno = rc;
		if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0)
			return -EFAULT;
		return 0;
	}
	if (no == MTIOCGET) {
		/* MTIOCGET: query the tape drive status. */
		struct mtget get;

		memset(&get, 0, sizeof(get));
		get.mt_type = MT_ISUNKNOWN;
		get.mt_resid = 0 /* device->devstat.rescnt */;
		get.mt_dsreg = device->tape_state;
		/* FIXME: mt_gstat, mt_erreg, mt_fileno */
		get.mt_gstat = 0;
		get.mt_erreg = 0;
		get.mt_fileno = 0;
		get.mt_gstat  = device->tape_generic_status;

		if (device->medium_state == MS_LOADED) {
			rc = tape_mtop(device, MTTELL, 1);

			if (rc < 0)
				return rc;

			if (rc == 0)
				get.mt_gstat |= GMT_BOT(~0);

			get.mt_blkno = rc;
		}

		if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0)
			return -EFAULT;

		return 0;
	}
	/* Try the discipline ioctl function. */
	if (device->discipline->ioctl_fn == NULL)
		return -EINVAL;
	return device->discipline->ioctl_fn(device, no, data);
}

static long
tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
{
	struct tape_device *device = filp->private_data;
	int rval = -ENOIOCTLCMD;

	if (device->discipline->ioctl_fn) {
		lock_kernel();
		rval = device->discipline->ioctl_fn(device, no, data);
		unlock_kernel();
		if (rval == -EINVAL)
			rval = -ENOIOCTLCMD;
	}

	return rval;
}

/*
 * Initialize character device frontend.
 */
int
tapechar_init (void)
{
	dev_t	dev;

	if (alloc_chrdev_region(&dev, 0, 256, "tape") != 0)
		return -1;

	tapechar_major = MAJOR(dev);

	return 0;
}

/*
 * cleanup
 */
void
tapechar_exit(void)
{
	unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/s390/char/tape_char.c
	3	* character device frontend for tape device driver
	4	*
	5	* S390 and zSeries version
cced1dd4	6	* Copyright IBM Corp. 2001,2006
1da177e4 LT	7	* Author(s): Carsten Otte <cotte@de.ibm.com>
	8	* Michael Holzheu <holzheu@de.ibm.com>
	9	* Tuan Ngo-Anh <ngoanh@de.ibm.com>
	10	* Martin Schwidefsky <schwidefsky@de.ibm.com>
	11	*/
	12
1da177e4 LT	13	#include <linux/module.h>
	14	#include <linux/types.h>
	15	#include <linux/proc_fs.h>
	16	#include <linux/mtio.h>
764a4a8e	17	#include <linux/smp_lock.h>
1da177e4 LT	18
	19	#include <asm/uaccess.h>
	20
	21	#define TAPE_DBF_AREA tape_core_dbf
	22
	23	#include "tape.h"
	24	#include "tape_std.h"
	25	#include "tape_class.h"
	26
1da177e4 LT	27	#define TAPECHAR_MAJOR 0 /* get dynamic major */
	28
	29	/*
	30	* file operation structure for tape character frontend
	31	*/
	32	static ssize_t tapechar_read(struct file , char __user , size_t, loff_t *);
	33	static ssize_t tapechar_write(struct file , const char __user , size_t, loff_t *);
	34	static int tapechar_open(struct inode ,struct file );
	35	static int tapechar_release(struct inode ,struct file );
	36	static int tapechar_ioctl(struct inode , struct file , unsigned int,
	37	unsigned long);
f042e0f8 CH	38	static long tapechar_compat_ioctl(struct file *, unsigned int,
f042e0f8 CH	39	unsigned long);
1da177e4	40
d54b1fdb	41	static const struct file_operations tape_fops =
1da177e4 LT	42	{
	43	.owner = THIS_MODULE,
	44	.read = tapechar_read,
	45	.write = tapechar_write,
	46	.ioctl = tapechar_ioctl,
f042e0f8	47	.compat_ioctl = tapechar_compat_ioctl,
1da177e4 LT	48	.open = tapechar_open,
	49	.release = tapechar_release,
	50	};
	51
	52	static int tapechar_major = TAPECHAR_MAJOR;
	53
	54	/*
	55	* This function is called for every new tapedevice
	56	*/
	57	int
	58	tapechar_setup_device(struct tape_device * device)
	59	{
	60	char device_name[20];
	61
	62	sprintf(device_name, "ntibm%i", device->first_minor / 2);
	63	device->nt = register_tape_dev(
	64	&device->cdev->dev,
	65	MKDEV(tapechar_major, device->first_minor),
	66	&tape_fops,
	67	device_name,
	68	"non-rewinding"
	69	);
	70	device_name[0] = 'r';
	71	device->rt = register_tape_dev(
	72	&device->cdev->dev,
	73	MKDEV(tapechar_major, device->first_minor + 1),
	74	&tape_fops,
	75	device_name,
	76	"rewinding"
	77	);
	78
	79	return 0;
	80	}
	81
	82	void
	83	tapechar_cleanup_device(struct tape_device *device)
	84	{
92bf435f	85	unregister_tape_dev(&device->cdev->dev, device->rt);
1da177e4	86	device->rt = NULL;
92bf435f	87	unregister_tape_dev(&device->cdev->dev, device->nt);
1da177e4 LT	88	device->nt = NULL;
	89	}
	90
4d284cac	91	static int
1da177e4 LT	92	tapechar_check_idalbuffer(struct tape_device *device, size_t block_size)
	93	{
	94	struct idal_buffer *new;
	95
	96	if (device->char_data.idal_buf != NULL &&
	97	device->char_data.idal_buf->size == block_size)
	98	return 0;
	99
	100	if (block_size > MAX_BLOCKSIZE) {
	101	DBF_EVENT(3, "Invalid blocksize (%zd > %d)\n",
	102	block_size, MAX_BLOCKSIZE);
1da177e4 LT	103	return -EINVAL;
	104	}
	105
	106	/* The current idal buffer is not correct. Allocate a new one. */
	107	new = idal_buffer_alloc(block_size, 0);
0983e568	108	if (IS_ERR(new))
1da177e4 LT	109	return -ENOMEM;
	110
	111	if (device->char_data.idal_buf != NULL)
	112	idal_buffer_free(device->char_data.idal_buf);
	113
	114	device->char_data.idal_buf = new;
	115
	116	return 0;
	117	}
	118
	119	/*
	120	* Tape device read function
	121	*/
2b67fc46	122	static ssize_t
1da177e4 LT	123	tapechar_read(struct file filp, char __user data, size_t count, loff_t *ppos)
	124	{
	125	struct tape_device *device;
	126	struct tape_request *request;
	127	size_t block_size;
	128	int rc;
	129
	130	DBF_EVENT(6, "TCHAR:read\n");
	131	device = (struct tape_device *) filp->private_data;
	132
	133	/*
	134	* If the tape isn't terminated yet, do it now. And since we then
	135	* are at the end of the tape there wouldn't be anything to read
	136	* anyways. So we return immediatly.
	137	*/
	138	if(device->required_tapemarks) {
	139	return tape_std_terminate_write(device);
	140	}
	141
	142	/* Find out block size to use */
	143	if (device->char_data.block_size != 0) {
	144	if (count < device->char_data.block_size) {
	145	DBF_EVENT(3, "TCHAR:read smaller than block "
	146	"size was requested\n");
	147	return -EINVAL;
	148	}
	149	block_size = device->char_data.block_size;
	150	} else {
	151	block_size = count;
	152	}
	153
	154	rc = tapechar_check_idalbuffer(device, block_size);
	155	if (rc)
	156	return rc;
	157
	158	#ifdef CONFIG_S390_TAPE_BLOCK
	159	/* Changes position. */
	160	device->blk_data.medium_changed = 1;
	161	#endif
	162
	163	DBF_EVENT(6, "TCHAR:nbytes: %lx\n", block_size);
	164	/* Let the discipline build the ccw chain. */
	165	request = device->discipline->read_block(device, block_size);
	166	if (IS_ERR(request))
	167	return PTR_ERR(request);
	168	/* Execute it. */
	169	rc = tape_do_io(device, request);
	170	if (rc == 0) {
	171	rc = block_size - request->rescnt;
	172	DBF_EVENT(6, "TCHAR:rbytes: %x\n", rc);
1da177e4 LT	173	/* Copy data from idal buffer to user space. */
	174	if (idal_buffer_to_user(device->char_data.idal_buf,
	175	data, rc) != 0)
	176	rc = -EFAULT;
	177	}
	178	tape_free_request(request);
	179	return rc;
	180	}
	181
	182	/*
	183	* Tape device write function
	184	*/
2b67fc46	185	static ssize_t
1da177e4 LT	186	tapechar_write(struct file filp, const char __user data, size_t count, loff_t *ppos)
	187	{
	188	struct tape_device *device;
	189	struct tape_request *request;
	190	size_t block_size;
	191	size_t written;
	192	int nblocks;
	193	int i, rc;
	194
	195	DBF_EVENT(6, "TCHAR:write\n");
	196	device = (struct tape_device *) filp->private_data;
	197	/* Find out block size and number of blocks */
	198	if (device->char_data.block_size != 0) {
	199	if (count < device->char_data.block_size) {
	200	DBF_EVENT(3, "TCHAR:write smaller than block "
	201	"size was requested\n");
	202	return -EINVAL;
	203	}
	204	block_size = device->char_data.block_size;
	205	nblocks = count / block_size;
	206	} else {
	207	block_size = count;
	208	nblocks = 1;
	209	}
	210
	211	rc = tapechar_check_idalbuffer(device, block_size);
	212	if (rc)
	213	return rc;
	214
	215	#ifdef CONFIG_S390_TAPE_BLOCK
	216	/* Changes position. */
	217	device->blk_data.medium_changed = 1;
	218	#endif
	219
	220	DBF_EVENT(6,"TCHAR:nbytes: %lx\n", block_size);
	221	DBF_EVENT(6, "TCHAR:nblocks: %x\n", nblocks);
	222	/* Let the discipline build the ccw chain. */
	223	request = device->discipline->write_block(device, block_size);
	224	if (IS_ERR(request))
	225	return PTR_ERR(request);
	226	rc = 0;
	227	written = 0;
	228	for (i = 0; i < nblocks; i++) {
	229	/* Copy data from user space to idal buffer. */
	230	if (idal_buffer_from_user(device->char_data.idal_buf,
	231	data, block_size)) {
	232	rc = -EFAULT;
	233	break;
	234	}
	235	rc = tape_do_io(device, request);
	236	if (rc)
	237	break;
	238	DBF_EVENT(6, "TCHAR:wbytes: %lx\n",
	239	block_size - request->rescnt);
1da177e4 LT	240	written += block_size - request->rescnt;
	241	if (request->rescnt != 0)
	242	break;
	243	data += block_size;
	244	}
	245	tape_free_request(request);
	246	if (rc == -ENOSPC) {
	247	/*
	248	* Ok, the device has no more space. It has NOT written
	249	* the block.
	250	*/
	251	if (device->discipline->process_eov)
	252	device->discipline->process_eov(device);
	253	if (written > 0)
	254	rc = 0;
	255
	256	}
	257
	258	/*
	259	* After doing a write we always need two tapemarks to correctly
	260	* terminate the tape (one to terminate the file, the second to
	261	* flag the end of recorded data.
	262	* Since process_eov positions the tape in front of the written
	263	* tapemark it doesn't hurt to write two marks again.
	264	*/
	265	if (!rc)
	266	device->required_tapemarks = 2;
	267
	268	return rc ? rc : written;
	269	}
	270
	271	/*
	272	* Character frontend tape device open function.
	273	*/
2b67fc46	274	static int
1da177e4 LT	275	tapechar_open (struct inode inode, struct file filp)
	276	{
	277	struct tape_device *device;
	278	int minor, rc;
	279
	280	DBF_EVENT(6, "TCHAR:open: %i:%i\n",
49522c97 JS	281	imajor(filp->f_path.dentry->d_inode),
49522c97 JS	282	iminor(filp->f_path.dentry->d_inode));
1da177e4	283
49522c97	284	if (imajor(filp->f_path.dentry->d_inode) != tapechar_major)
1da177e4 LT	285	return -ENODEV;
1da177e4 LT	286
764a4a8e	287	lock_kernel();
49522c97	288	minor = iminor(filp->f_path.dentry->d_inode);
8fd138c3	289	device = tape_find_device(minor / TAPE_MINORS_PER_DEV);
1da177e4	290	if (IS_ERR(device)) {
8fd138c3	291	DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n");
764a4a8e JC	292	rc = PTR_ERR(device);
764a4a8e JC	293	goto out;
1da177e4 LT	294	}
	295
	296
	297	rc = tape_open(device);
	298	if (rc == 0) {
	299	filp->private_data = device;
764a4a8e	300	rc = nonseekable_open(inode, filp);
1da177e4	301	}
764a4a8e JC	302	else
764a4a8e JC	303	tape_put_device(device);
1da177e4	304
764a4a8e JC	305	out:
764a4a8e JC	306	unlock_kernel();
1da177e4 LT	307	return rc;
	308	}
	309
	310	/*
	311	* Character frontend tape device release function.
	312	*/
	313
2b67fc46	314	static int
1da177e4 LT	315	tapechar_release(struct inode inode, struct file filp)
	316	{
	317	struct tape_device *device;
	318
	319	DBF_EVENT(6, "TCHAR:release: %x\n", iminor(inode));
	320	device = (struct tape_device *) filp->private_data;
	321
	322	/*
	323	* If this is the rewinding tape minor then rewind. In that case we
	324	* write all required tapemarks. Otherwise only one to terminate the
	325	* file.
	326	*/
	327	if ((iminor(inode) & 1) != 0) {
	328	if (device->required_tapemarks)
	329	tape_std_terminate_write(device);
	330	tape_mtop(device, MTREW, 1);
	331	} else {
	332	if (device->required_tapemarks > 1) {
	333	if (tape_mtop(device, MTWEOF, 1) == 0)
	334	device->required_tapemarks--;
	335	}
	336	}
	337
	338	if (device->char_data.idal_buf != NULL) {
	339	idal_buffer_free(device->char_data.idal_buf);
	340	device->char_data.idal_buf = NULL;
	341	}
	342	tape_release(device);
8fd138c3 MS	343	filp->private_data = NULL;
8fd138c3 MS	344	tape_put_device(device);
1da177e4 LT	345
	346	return 0;
	347	}
	348
	349	/*
	350	* Tape device io controls.
	351	*/
	352	static int
	353	tapechar_ioctl(struct inode inp, struct file filp,
	354	unsigned int no, unsigned long data)
	355	{
	356	struct tape_device *device;
	357	int rc;
	358
	359	DBF_EVENT(6, "TCHAR:ioct\n");
	360
	361	device = (struct tape_device *) filp->private_data;
	362
	363	if (no == MTIOCTOP) {
	364	struct mtop op;
	365
	366	if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0)
	367	return -EFAULT;
	368	if (op.mt_count < 0)
	369	return -EINVAL;
	370
	371	/*
	372	* Operations that change tape position should write final
	373	* tapemarks.
	374	*/
	375	switch (op.mt_op) {
	376	case MTFSF:
	377	case MTBSF:
	378	case MTFSR:
	379	case MTBSR:
	380	case MTREW:
	381	case MTOFFL:
	382	case MTEOM:
	383	case MTRETEN:
	384	case MTBSFM:
	385	case MTFSFM:
	386	case MTSEEK:
	387	#ifdef CONFIG_S390_TAPE_BLOCK
	388	device->blk_data.medium_changed = 1;
	389	#endif
	390	if (device->required_tapemarks)
	391	tape_std_terminate_write(device);
	392	default:
	393	;
	394	}
	395	rc = tape_mtop(device, op.mt_op, op.mt_count);
	396
	397	if (op.mt_op == MTWEOF && rc == 0) {
	398	if (op.mt_count > device->required_tapemarks)
	399	device->required_tapemarks = 0;
	400	else
	401	device->required_tapemarks -= op.mt_count;
	402	}
	403	return rc;
	404	}
	405	if (no == MTIOCPOS) {
	406	/* MTIOCPOS: query the tape position. */
	407	struct mtpos pos;
	408
409	rc = tape_mtop(device, MTTELL, 1);
410	if (rc < 0)
411	return rc;
412	pos.mt_blkno = rc;
413	if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0)
414	return -EFAULT;
415	return 0;
416	}
417	if (no == MTIOCGET) {
418	/* MTIOCGET: query the tape drive status. */
419	struct mtget get;
420
421	memset(&get, 0, sizeof(get));
422	get.mt_type = MT_ISUNKNOWN;
423	get.mt_resid = 0 /* device->devstat.rescnt */;
424	get.mt_dsreg = device->tape_state;
425	/* FIXME: mt_gstat, mt_erreg, mt_fileno */
426	get.mt_gstat = 0;
427	get.mt_erreg = 0;
428	get.mt_fileno = 0;
429	get.mt_gstat = device->tape_generic_status;
430
431	if (device->medium_state == MS_LOADED) {
432	rc = tape_mtop(device, MTTELL, 1);
433
434	if (rc < 0)
435	return rc;
436
437	if (rc == 0)
438	get.mt_gstat \|= GMT_BOT(~0);
439
440	get.mt_blkno = rc;
441	}
442
443	if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0)
444	return -EFAULT;
445
446	return 0;
447	}
448	/* Try the discipline ioctl function. */
449	if (device->discipline->ioctl_fn == NULL)
450	return -EINVAL;
451	return device->discipline->ioctl_fn(device, no, data);
452	}
453
f042e0f8 CH	454	static long
	455	tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
	456	{
	457	struct tape_device *device = filp->private_data;
	458	int rval = -ENOIOCTLCMD;
	459
	460	if (device->discipline->ioctl_fn) {
	461	lock_kernel();
	462	rval = device->discipline->ioctl_fn(device, no, data);
	463	unlock_kernel();
	464	if (rval == -EINVAL)
	465	rval = -ENOIOCTLCMD;
	466	}
	467
	468	return rval;
	469	}
	470
1da177e4 LT	471	/*
	472	* Initialize character device frontend.
	473	*/
	474	int
	475	tapechar_init (void)
	476	{
	477	dev_t dev;
	478
	479	if (alloc_chrdev_region(&dev, 0, 256, "tape") != 0)
	480	return -1;
	481
	482	tapechar_major = MAJOR(dev);
1da177e4 LT	483
	484	return 0;
	485	}
	486
	487	/*
	488	* cleanup
	489	*/
	490	void
	491	tapechar_exit(void)
	492	{
1da177e4 LT	493	unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
1da177e4 LT	494	}