linux/drivers/s390/char/tape_char.c

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/*
* 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 <asm/uaccess.h>
#define TAPE_DBF_AREA tape_core_dbf
#include "tape.h"
#include "tape_std.h"
#include "tape_class.h"
#define PRINTK_HEADER "TAPE_CHAR: "
#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->rt);
device->rt = NULL;
unregister_tape_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);
PRINT_ERR("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 (new == NULL)
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);
filp->f_pos += 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);
filp->f_pos += 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;
minor = iminor(filp->f_path.dentry->d_inode);
device = tape_get_device(minor / TAPE_MINORS_PER_DEV);
if (IS_ERR(device)) {
DBF_EVENT(3, "TCHAR:open: tape_get_device() failed\n");
return PTR_ERR(device);
}
rc = tape_open(device);
if (rc == 0) {
filp->private_data = device;
return nonseekable_open(inode, filp);
}
tape_put_device(device);
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 = 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);
PRINT_INFO("tape gets major %d for character devices\n", MAJOR(dev));
return 0;
}
/*
* cleanup
*/
void
tapechar_exit(void)
{
PRINT_INFO("tape releases major %d for character devices\n",
tapechar_major);
unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
}