diff options
Diffstat (limited to 'drivers/s390/char/vmur.c')
| -rw-r--r-- | drivers/s390/char/vmur.c | 906 |
1 files changed, 906 insertions, 0 deletions
diff --git a/drivers/s390/char/vmur.c b/drivers/s390/char/vmur.c new file mode 100644 index 00000000000..e90b0f84619 --- /dev/null +++ b/drivers/s390/char/vmur.c @@ -0,0 +1,906 @@ +/* + * Linux driver for System z and s390 unit record devices + * (z/VM virtual punch, reader, printer) + * + * Copyright IBM Corp. 2001, 2007 + * Authors: Malcolm Beattie <beattiem@uk.ibm.com> + * Michael Holzheu <holzheu@de.ibm.com> + * Frank Munzert <munzert@de.ibm.com> + */ + +#include <linux/cdev.h> + +#include <asm/uaccess.h> +#include <asm/cio.h> +#include <asm/ccwdev.h> +#include <asm/debug.h> + +#include "vmur.h" + +/* + * Driver overview + * + * Unit record device support is implemented as a character device driver. + * We can fit at least 16 bits into a device minor number and use the + * simple method of mapping a character device number with minor abcd + * to the unit record device with devno abcd. + * I/O to virtual unit record devices is handled as follows: + * Reads: Diagnose code 0x14 (input spool file manipulation) + * is used to read spool data page-wise. + * Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length + * is available by reading sysfs attr reclen. Each write() to the device + * must specify an integral multiple (maximal 511) of reclen. + */ + +static char ur_banner[] = "z/VM virtual unit record device driver"; + +MODULE_AUTHOR("IBM Corporation"); +MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver"); +MODULE_LICENSE("GPL"); + +#define PRINTK_HEADER "vmur: " + +static dev_t ur_first_dev_maj_min; +static struct class *vmur_class; +static struct debug_info *vmur_dbf; + +/* We put the device's record length (for writes) in the driver_info field */ +static struct ccw_device_id ur_ids[] = { + { CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) }, + { CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) }, + { /* end of list */ } +}; + +MODULE_DEVICE_TABLE(ccw, ur_ids); + +static int ur_probe(struct ccw_device *cdev); +static void ur_remove(struct ccw_device *cdev); +static int ur_set_online(struct ccw_device *cdev); +static int ur_set_offline(struct ccw_device *cdev); + +static struct ccw_driver ur_driver = { + .name = "vmur", + .owner = THIS_MODULE, + .ids = ur_ids, + .probe = ur_probe, + .remove = ur_remove, + .set_online = ur_set_online, + .set_offline = ur_set_offline, +}; + +/* + * Allocation, freeing, getting and putting of urdev structures + */ +static struct urdev *urdev_alloc(struct ccw_device *cdev) +{ + struct urdev *urd; + + urd = kzalloc(sizeof(struct urdev), GFP_KERNEL); + if (!urd) + return NULL; + urd->cdev = cdev; + urd->reclen = cdev->id.driver_info; + ccw_device_get_id(cdev, &urd->dev_id); + mutex_init(&urd->io_mutex); + mutex_init(&urd->open_mutex); + return urd; +} + +static void urdev_free(struct urdev *urd) +{ + kfree(urd); +} + +/* + * This is how the character device driver gets a reference to a + * ur device. When this call returns successfully, a reference has + * been taken (by get_device) on the underlying kobject. The recipient + * of this urdev pointer must eventually drop it with urdev_put(urd) + * which does the corresponding put_device(). + */ +static struct urdev *urdev_get_from_devno(u16 devno) +{ + char bus_id[16]; + struct ccw_device *cdev; + + sprintf(bus_id, "0.0.%04x", devno); + cdev = get_ccwdev_by_busid(&ur_driver, bus_id); + if (!cdev) + return NULL; + + return cdev->dev.driver_data; +} + +static void urdev_put(struct urdev *urd) +{ + put_device(&urd->cdev->dev); +} + +/* + * Low-level functions to do I/O to a ur device. + * alloc_chan_prog + * do_ur_io + * ur_int_handler + * + * alloc_chan_prog allocates and builds the channel program + * + * do_ur_io issues the channel program to the device and blocks waiting + * on a completion event it publishes at urd->io_done. The function + * serialises itself on the device's mutex so that only one I/O + * is issued at a time (and that I/O is synchronous). + * + * ur_int_handler catches the "I/O done" interrupt, writes the + * subchannel status word into the scsw member of the urdev structure + * and complete()s the io_done to wake the waiting do_ur_io. + * + * The caller of do_ur_io is responsible for kfree()ing the channel program + * address pointer that alloc_chan_prog returned. + */ + + +/* + * alloc_chan_prog + * The channel program we use is write commands chained together + * with a final NOP CCW command-chained on (which ensures that CE and DE + * are presented together in a single interrupt instead of as separate + * interrupts unless an incorrect length indication kicks in first). The + * data length in each CCW is reclen. The caller must ensure that count + * is an integral multiple of reclen. + * The channel program pointer returned by this function must be freed + * with kfree. The caller is responsible for checking that + * count/reclen is not ridiculously large. + */ +static struct ccw1 *alloc_chan_prog(char *buf, size_t count, size_t reclen) +{ + size_t num_ccws; + struct ccw1 *cpa; + int i; + + TRACE("alloc_chan_prog(%p, %zu, %zu)\n", buf, count, reclen); + + /* + * We chain a NOP onto the writes to force CE+DE together. + * That means we allocate room for CCWs to cover count/reclen + * records plus a NOP. + */ + num_ccws = count / reclen + 1; + cpa = kmalloc(num_ccws * sizeof(struct ccw1), GFP_KERNEL | GFP_DMA); + if (!cpa) + return NULL; + + for (i = 0; count; i++) { + cpa[i].cmd_code = WRITE_CCW_CMD; + cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI; + cpa[i].count = reclen; + cpa[i].cda = __pa(buf); + buf += reclen; + count -= reclen; + } + /* The following NOP CCW forces CE+DE to be presented together */ + cpa[i].cmd_code = CCW_CMD_NOOP; + cpa[i].flags = 0; + cpa[i].count = 0; + cpa[i].cda = 0; + + return cpa; +} + +static int do_ur_io(struct urdev *urd, struct ccw1 *cpa) +{ + int rc; + struct ccw_device *cdev = urd->cdev; + DECLARE_COMPLETION(event); + + TRACE("do_ur_io: cpa=%p\n", cpa); + + rc = mutex_lock_interruptible(&urd->io_mutex); + if (rc) + return rc; + + urd->io_done = &event; + + spin_lock_irq(get_ccwdev_lock(cdev)); + rc = ccw_device_start(cdev, cpa, 1, 0, 0); + spin_unlock_irq(get_ccwdev_lock(cdev)); + + TRACE("do_ur_io: ccw_device_start returned %d\n", rc); + if (rc) + goto out; + + wait_for_completion(&event); + TRACE("do_ur_io: I/O complete\n"); + rc = 0; + +out: + mutex_unlock(&urd->io_mutex); + return rc; +} + +/* + * ur interrupt handler, called from the ccw_device layer + */ +static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm, + struct irb *irb) +{ + struct urdev *urd; + + TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n", + intparm, irb->scsw.cstat, irb->scsw.dstat, irb->scsw.count); + + if (!intparm) { + TRACE("ur_int_handler: unsolicited interrupt\n"); + return; + } + urd = cdev->dev.driver_data; + /* On special conditions irb is an error pointer */ + if (IS_ERR(irb)) + urd->io_request_rc = PTR_ERR(irb); + else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END)) + urd->io_request_rc = 0; + else + urd->io_request_rc = -EIO; + + complete(urd->io_done); +} + +/* + * reclen sysfs attribute - The record length to be used for write CCWs + */ +static ssize_t ur_attr_reclen_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct urdev *urd = dev->driver_data; + + return sprintf(buf, "%zu\n", urd->reclen); +} + +static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL); + +static int ur_create_attributes(struct device *dev) +{ + return device_create_file(dev, &dev_attr_reclen); +} + +static void ur_remove_attributes(struct device *dev) +{ + device_remove_file(dev, &dev_attr_reclen); +} + +/* + * diagnose code 0x210 - retrieve device information + * cc=0 normal completion, we have a real device + * cc=1 CP paging error + * cc=2 The virtual device exists, but is not associated with a real device + * cc=3 Invalid device address, or the virtual device does not exist + */ +static int get_urd_class(struct urdev *urd) +{ + static struct diag210 ur_diag210; + int cc; + + ur_diag210.vrdcdvno = urd->dev_id.devno; + ur_diag210.vrdclen = sizeof(struct diag210); + + cc = diag210(&ur_diag210); + switch (cc) { + case 0: + return -ENOTSUPP; + case 2: + return ur_diag210.vrdcvcla; /* virtual device class */ + case 3: + return -ENODEV; + default: + return -EIO; + } +} + +/* + * Allocation and freeing of urfile structures + */ +static struct urfile *urfile_alloc(struct urdev *urd) +{ + struct urfile *urf; + + urf = kzalloc(sizeof(struct urfile), GFP_KERNEL); + if (!urf) + return NULL; + urf->urd = urd; + + TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf, + urf->dev_reclen); + + return urf; +} + +static void urfile_free(struct urfile *urf) +{ + TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd); + kfree(urf); +} + +/* + * The fops implementation of the character device driver + */ +static ssize_t do_write(struct urdev *urd, const char __user *udata, + size_t count, size_t reclen, loff_t *ppos) +{ + struct ccw1 *cpa; + char *buf; + int rc; + + /* Data buffer must be under 2GB line for fmt1 CCWs: hence GFP_DMA */ + buf = kmalloc(count, GFP_KERNEL | GFP_DMA); + if (!buf) + return -ENOMEM; + + if (copy_from_user(buf, udata, count)) { + rc = -EFAULT; + goto fail_kfree_buf; + } + + cpa = alloc_chan_prog(buf, count, reclen); + if (!cpa) { + rc = -ENOMEM; + goto fail_kfree_buf; + } + + rc = do_ur_io(urd, cpa); + if (rc) + goto fail_kfree_cpa; + + if (urd->io_request_rc) { + rc = urd->io_request_rc; + goto fail_kfree_cpa; + } + *ppos += count; + rc = count; +fail_kfree_cpa: + kfree(cpa); +fail_kfree_buf: + kfree(buf); + return rc; +} + +static ssize_t ur_write(struct file *file, const char __user *udata, + size_t count, loff_t *ppos) +{ + struct urfile *urf = file->private_data; + + TRACE("ur_write: count=%zu\n", count); + + if (count == 0) + return 0; + + if (count % urf->dev_reclen) + return -EINVAL; /* count must be a multiple of reclen */ + + if (count > urf->dev_reclen * MAX_RECS_PER_IO) + count = urf->dev_reclen * MAX_RECS_PER_IO; + + return do_write(urf->urd, udata, count, urf->dev_reclen, ppos); +} + +static int do_diag_14(unsigned long rx, unsigned long ry1, + unsigned long subcode) +{ + register unsigned long _ry1 asm("2") = ry1; + register unsigned long _ry2 asm("3") = subcode; + int rc = 0; + + asm volatile( +#ifdef CONFIG_64BIT + " sam31\n" + " diag %2,2,0x14\n" + " sam64\n" +#else + " diag %2,2,0x14\n" +#endif + " ipm %0\n" + " srl %0,28\n" + : "=d" (rc), "+d" (_ry2) + : "d" (rx), "d" (_ry1) + : "cc"); + + TRACE("diag 14: subcode=0x%lx, cc=%i\n", subcode, rc); + return rc; +} + +/* + * diagnose code 0x14 subcode 0x0028 - position spool file to designated + * record + * cc=0 normal completion + * cc=2 no file active on the virtual reader or device not ready + * cc=3 record specified is beyond EOF + */ +static int diag_position_to_record(int devno, int record) +{ + int cc; + + cc = do_diag_14(record, devno, 0x28); + switch (cc) { + case 0: + return 0; + case 2: + return -ENOMEDIUM; + case 3: + return -ENODATA; /* position beyond end of file */ + default: + return -EIO; + } +} + +/* + * diagnose code 0x14 subcode 0x0000 - read next spool file buffer + * cc=0 normal completion + * cc=1 EOF reached + * cc=2 no file active on the virtual reader, and no file eligible + * cc=3 file already active on the virtual reader or specified virtual + * reader does not exist or is not a reader + */ +static int diag_read_file(int devno, char *buf) +{ + int cc; + + cc = do_diag_14((unsigned long) buf, devno, 0x00); + switch (cc) { + case 0: + return 0; + case 1: + return -ENODATA; + case 2: + return -ENOMEDIUM; + default: + return -EIO; + } +} + +static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count, + loff_t *offs) +{ + size_t len, copied, res; + char *buf; + int rc; + u16 reclen; + struct urdev *urd; + + urd = ((struct urfile *) file->private_data)->urd; + reclen = ((struct urfile *) file->private_data)->file_reclen; + + rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1); + if (rc == -ENODATA) + return 0; + if (rc) + return rc; + + len = min((size_t) PAGE_SIZE, count); + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + copied = 0; + res = (size_t) (*offs % PAGE_SIZE); + do { + rc = diag_read_file(urd->dev_id.devno, buf); + if (rc == -ENODATA) { + break; + } + if (rc) + goto fail; + if (reclen) + *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen; + len = min(count - copied, PAGE_SIZE - res); + if (copy_to_user(ubuf + copied, buf + res, len)) { + rc = -EFAULT; + goto fail; + } + res = 0; + copied += len; + } while (copied != count); + + *offs += copied; + rc = copied; +fail: + kfree(buf); + return rc; +} + +static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count, + loff_t *offs) +{ + struct urdev *urd; + int rc; + + TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs); + + if (count == 0) + return 0; + + urd = ((struct urfile *) file->private_data)->urd; + rc = mutex_lock_interruptible(&urd->io_mutex); + if (rc) + return rc; + rc = diag14_read(file, ubuf, count, offs); + mutex_unlock(&urd->io_mutex); + return rc; +} + +/* + * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor + * cc=0 normal completion + * cc=1 no files on reader queue or no subsequent file + * cc=2 spid specified is invalid + */ +static int diag_read_next_file_info(struct file_control_block *buf, int spid) +{ + int cc; + + cc = do_diag_14((unsigned long) buf, spid, 0xfff); + switch (cc) { + case 0: + return 0; + default: + return -ENODATA; + } +} + +static int verify_device(struct urdev *urd) +{ + struct file_control_block fcb; + char *buf; + int rc; + + switch (urd->class) { + case DEV_CLASS_UR_O: + return 0; /* no check needed here */ + case DEV_CLASS_UR_I: + /* check for empty reader device (beginning of chain) */ + rc = diag_read_next_file_info(&fcb, 0); + if (rc) + return rc; + + /* open file on virtual reader */ + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = diag_read_file(urd->dev_id.devno, buf); + kfree(buf); + + if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */ + return rc; + return 0; + default: + return -ENOTSUPP; + } +} + +static int get_file_reclen(struct urdev *urd) +{ + struct file_control_block fcb; + int rc; + + switch (urd->class) { + case DEV_CLASS_UR_O: + return 0; + case DEV_CLASS_UR_I: + rc = diag_read_next_file_info(&fcb, 0); + if (rc) + return rc; + break; + default: + return -ENOTSUPP; + } + if (fcb.file_stat & FLG_CP_DUMP) + return 0; + + return fcb.rec_len; +} + +static int ur_open(struct inode *inode, struct file *file) +{ + u16 devno; + struct urdev *urd; + struct urfile *urf; + unsigned short accmode; + int rc; + + accmode = file->f_flags & O_ACCMODE; + + if (accmode == O_RDWR) + return -EACCES; + + /* + * We treat the minor number as the devno of the ur device + * to find in the driver tree. + */ + devno = MINOR(file->f_dentry->d_inode->i_rdev); + + urd = urdev_get_from_devno(devno); + if (!urd) + return -ENXIO; + + if (file->f_flags & O_NONBLOCK) { + if (!mutex_trylock(&urd->open_mutex)) { + rc = -EBUSY; + goto fail_put; + } + } else { + if (mutex_lock_interruptible(&urd->open_mutex)) { + rc = -ERESTARTSYS; + goto fail_put; + } + } + + TRACE("ur_open\n"); + + if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) || + ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) { + TRACE("ur_open: unsupported dev class (%d)\n", urd->class); + rc = -EACCES; + goto fail_unlock; + } + + rc = verify_device(urd); + if (rc) + goto fail_unlock; + + urf = urfile_alloc(urd); + if (!urf) { + rc = -ENOMEM; + goto fail_unlock; + } + + urf->dev_reclen = urd->reclen; + rc = get_file_reclen(urd); + if (rc < 0) + goto fail_urfile_free; + urf->file_reclen = rc; + file->private_data = urf; + return 0; + +fail_urfile_free: + urfile_free(urf); +fail_unlock: + mutex_unlock(&urd->open_mutex); +fail_put: + urdev_put(urd); + return rc; +} + +static int ur_release(struct inode *inode, struct file *file) +{ + struct urfile *urf = file->private_data; + + TRACE("ur_release\n"); + mutex_unlock(&urf->urd->open_mutex); + urdev_put(urf->urd); + urfile_free(urf); + return 0; +} + +static loff_t ur_llseek(struct file *file, loff_t offset, int whence) +{ + loff_t newpos; + + if ((file->f_flags & O_ACCMODE) != O_RDONLY) + return -ESPIPE; /* seek allowed only for reader */ + if (offset % PAGE_SIZE) + return -ESPIPE; /* only multiples of 4K allowed */ + switch (whence) { + case 0: /* SEEK_SET */ + newpos = offset; + break; + case 1: /* SEEK_CUR */ + newpos = file->f_pos + offset; + break; + default: + return -EINVAL; + } + file->f_pos = newpos; + return newpos; +} + +static struct file_operations ur_fops = { + .owner = THIS_MODULE, + .open = ur_open, + .release = ur_release, + .read = ur_read, + .write = ur_write, + .llseek = ur_llseek, +}; + +/* + * ccw_device infrastructure: + * ur_probe gets its own ref to the device (i.e. get_device), + * creates the struct urdev, the device attributes, sets up + * the interrupt handler and validates the virtual unit record device. + * ur_remove removes the device attributes, frees the struct urdev + * and drops (put_device) the ref to the device we got in ur_probe. + */ +static int ur_probe(struct ccw_device *cdev) +{ + struct urdev *urd; + int rc; + + TRACE("ur_probe: cdev=%p state=%d\n", cdev, *(int *) cdev->private); + + if (!get_device(&cdev->dev)) + return -ENODEV; + + urd = urdev_alloc(cdev); + if (!urd) { + rc = -ENOMEM; + goto fail; + } + rc = ur_create_attributes(&cdev->dev); + if (rc) { + rc = -ENOMEM; + goto fail; + } + cdev->dev.driver_data = urd; + cdev->handler = ur_int_handler; + + /* validate virtual unit record device */ + urd->class = get_urd_class(urd); + if (urd->class < 0) { + rc = urd->class; + goto fail; + } + if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) { + rc = -ENOTSUPP; + goto fail; + } + + return 0; + +fail: + urdev_free(urd); + put_device(&cdev->dev); + return rc; +} + +static void ur_remove(struct ccw_device *cdev) +{ + struct urdev *urd = cdev->dev.driver_data; + + TRACE("ur_remove\n"); + if (cdev->online) + ur_set_offline(cdev); + ur_remove_attributes(&cdev->dev); + urdev_free(urd); + put_device(&cdev->dev); +} + +static int ur_set_online(struct ccw_device *cdev) +{ + struct urdev *urd; + int minor, major, rc; + char node_id[16]; + + TRACE("ur_set_online: cdev=%p state=%d\n", cdev, + *(int *) cdev->private); + + if (!try_module_get(ur_driver.owner)) + return -EINVAL; + + urd = (struct urdev *) cdev->dev.driver_data; + minor = urd->dev_id.devno; + major = MAJOR(ur_first_dev_maj_min); + + urd->char_device = cdev_alloc(); + if (!urd->char_device) { + rc = -ENOMEM; + goto fail_module_put; + } + + cdev_init(urd->char_device, &ur_fops); + urd->char_device->dev = MKDEV(major, minor); + urd->char_device->owner = ur_fops.owner; + + rc = cdev_add(urd->char_device, urd->char_device->dev, 1); + if (rc) + goto fail_free_cdev; + if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) { + if (urd->class == DEV_CLASS_UR_I) + sprintf(node_id, "vmrdr-%s", cdev->dev.bus_id); + if (urd->class == DEV_CLASS_UR_O) + sprintf(node_id, "vmpun-%s", cdev->dev.bus_id); + } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) { + sprintf(node_id, "vmprt-%s", cdev->dev.bus_id); + } else { + rc = -ENOTSUPP; + goto fail_free_cdev; + } + + urd->device = device_create(vmur_class, NULL, urd->char_device->dev, + "%s", node_id); + if (IS_ERR(urd->device)) { + rc = PTR_ERR(urd->device); + TRACE("ur_set_online: device_create rc=%d\n", rc); + goto fail_free_cdev; + } + + return 0; + +fail_free_cdev: + cdev_del(urd->char_device); +fail_module_put: + module_put(ur_driver.owner); + + return rc; +} + +static int ur_set_offline(struct ccw_device *cdev) +{ + struct urdev *urd; + + TRACE("ur_set_offline: cdev=%p cdev->private=%p state=%d\n", + cdev, cdev->private, *(int *) cdev->private); + urd = (struct urdev *) cdev->dev.driver_data; + device_destroy(vmur_class, urd->char_device->dev); + cdev_del(urd->char_device); + module_put(ur_driver.owner); + + return 0; +} + +/* + * Module initialisation and cleanup + */ +static int __init ur_init(void) +{ + int rc; + dev_t dev; + + if (!MACHINE_IS_VM) { + PRINT_ERR("%s is only available under z/VM.\n", ur_banner); + return -ENODEV; + } + + vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long)); + if (!vmur_dbf) + return -ENOMEM; + rc = debug_register_view(vmur_dbf, &debug_sprintf_view); + if (rc) + goto fail_free_dbf; + + debug_set_level(vmur_dbf, 6); + + rc = ccw_driver_register(&ur_driver); + if (rc) + goto fail_free_dbf; + + rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur"); + if (rc) { + PRINT_ERR("alloc_chrdev_region failed: err = %d\n", rc); + goto fail_unregister_driver; + } + ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0); + + vmur_class = class_create(THIS_MODULE, "vmur"); + if (IS_ERR(vmur_class)) { + rc = PTR_ERR(vmur_class); + goto fail_unregister_region; + } + PRINT_INFO("%s loaded.\n", ur_banner); + return 0; + +fail_unregister_region: + unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS); +fail_unregister_driver: + ccw_driver_unregister(&ur_driver); +fail_free_dbf: + debug_unregister(vmur_dbf); + return rc; +} + +static void __exit ur_exit(void) +{ + class_destroy(vmur_class); + unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS); + ccw_driver_unregister(&ur_driver); + debug_unregister(vmur_dbf); + PRINT_INFO("%s unloaded.\n", ur_banner); +} + +module_init(ur_init); +module_exit(ur_exit); |