diff options
Diffstat (limited to 'drivers/s390/char/tape_char.c')
| -rw-r--r-- | drivers/s390/char/tape_char.c | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/drivers/s390/char/tape_char.c b/drivers/s390/char/tape_char.c new file mode 100644 index 000000000..fc206c9d1 --- /dev/null +++ b/drivers/s390/char/tape_char.c @@ -0,0 +1,501 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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> + */ + +#define KMSG_COMPONENT "tape" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/proc_fs.h> +#include <linux/mtio.h> +#include <linux/compat.h> + +#include <linux/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 long tapechar_ioctl(struct file *, unsigned int, unsigned long); +#ifdef CONFIG_COMPAT +static long tapechar_compat_ioctl(struct file *, unsigned int, unsigned long); +#endif + +static const struct file_operations tape_fops = +{ + .owner = THIS_MODULE, + .read = tapechar_read, + .write = tapechar_write, + .unlocked_ioctl = tapechar_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = tapechar_compat_ioctl, +#endif + .open = tapechar_open, + .release = tapechar_release, + .llseek = no_llseek, +}; + +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 immediately. + */ + 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; + + 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; + + 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(file_inode(filp)), + iminor(file_inode(filp))); + + if (imajor(file_inode(filp)) != tapechar_major) + return -ENODEV; + + minor = iminor(file_inode(filp)); + device = tape_find_device(minor / TAPE_MINORS_PER_DEV); + if (IS_ERR(device)) { + DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n"); + return PTR_ERR(device); + } + + rc = tape_open(device); + if (rc == 0) { + filp->private_data = device; + nonseekable_open(inode, filp); + } else + 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 = NULL; + tape_put_device(device); + + return 0; +} + +/* + * Tape device io controls. + */ +static int +__tapechar_ioctl(struct tape_device *device, + unsigned int no, unsigned long data) +{ + int rc; + + 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: + 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->char_data.block_size << MT_ST_BLKSIZE_SHIFT) + & MT_ST_BLKSIZE_MASK); + /* 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_ioctl(struct file *filp, unsigned int no, unsigned long data) +{ + struct tape_device *device; + long rc; + + DBF_EVENT(6, "TCHAR:ioct\n"); + + device = (struct tape_device *) filp->private_data; + mutex_lock(&device->mutex); + rc = __tapechar_ioctl(device, no, data); + mutex_unlock(&device->mutex); + return rc; +} + +#ifdef CONFIG_COMPAT +static long +tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data) +{ + struct tape_device *device = filp->private_data; + int rval = -ENOIOCTLCMD; + unsigned long argp; + + /* The 'arg' argument of any ioctl function may only be used for + * pointers because of the compat pointer conversion. + * Consider this when adding new ioctls. + */ + argp = (unsigned long) compat_ptr(data); + if (device->discipline->ioctl_fn) { + mutex_lock(&device->mutex); + rval = device->discipline->ioctl_fn(device, no, argp); + mutex_unlock(&device->mutex); + if (rval == -EINVAL) + rval = -ENOIOCTLCMD; + } + + return rval; +} +#endif /* CONFIG_COMPAT */ + +/* + * 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); +} |