diff options
Diffstat (limited to 'drivers/s390/char/vmur.c')
| -rw-r--r-- | drivers/s390/char/vmur.c | 1058 |
1 files changed, 1058 insertions, 0 deletions
diff --git a/drivers/s390/char/vmur.c b/drivers/s390/char/vmur.c new file mode 100644 index 000000000..cbde65ab2 --- /dev/null +++ b/drivers/s390/char/vmur.c @@ -0,0 +1,1058 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Linux driver for System z and s390 unit record devices + * (z/VM virtual punch, reader, printer) + * + * Copyright IBM Corp. 2001, 2009 + * Authors: Malcolm Beattie <beattiem@uk.ibm.com> + * Michael Holzheu <holzheu@de.ibm.com> + * Frank Munzert <munzert@de.ibm.com> + */ + +#define KMSG_COMPONENT "vmur" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/cdev.h> +#include <linux/slab.h> +#include <linux/module.h> + +#include <linux/uaccess.h> +#include <asm/cio.h> +#include <asm/ccwdev.h> +#include <asm/debug.h> +#include <asm/diag.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"); + +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 int ur_pm_suspend(struct ccw_device *cdev); + +static struct ccw_driver ur_driver = { + .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, + .freeze = ur_pm_suspend, + .int_class = IRQIO_VMR, +}; + +static DEFINE_MUTEX(vmur_mutex); + +/* + * Allocation, freeing, getting and putting of urdev structures + * + * Each ur device (urd) contains a reference to its corresponding ccw device + * (cdev) using the urd->cdev pointer. Each ccw device has a reference to the + * ur device using dev_get_drvdata(&cdev->dev) pointer. + * + * urd references: + * - ur_probe gets a urd reference, ur_remove drops the reference + * dev_get_drvdata(&cdev->dev) + * - ur_open gets a urd reference, ur_release drops the reference + * (urf->urd) + * + * cdev references: + * - urdev_alloc get a cdev reference (urd->cdev) + * - urdev_free drops the cdev reference (urd->cdev) + * + * Setting and clearing of dev_get_drvdata(&cdev->dev) is protected by the ccwdev lock + */ +static struct urdev *urdev_alloc(struct ccw_device *cdev) +{ + struct urdev *urd; + + urd = kzalloc(sizeof(struct urdev), GFP_KERNEL); + if (!urd) + return NULL; + urd->reclen = cdev->id.driver_info; + ccw_device_get_id(cdev, &urd->dev_id); + mutex_init(&urd->io_mutex); + init_waitqueue_head(&urd->wait); + spin_lock_init(&urd->open_lock); + refcount_set(&urd->ref_count, 1); + urd->cdev = cdev; + get_device(&cdev->dev); + return urd; +} + +static void urdev_free(struct urdev *urd) +{ + TRACE("urdev_free: %p\n", urd); + if (urd->cdev) + put_device(&urd->cdev->dev); + kfree(urd); +} + +static void urdev_get(struct urdev *urd) +{ + refcount_inc(&urd->ref_count); +} + +static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev) +{ + struct urdev *urd; + unsigned long flags; + + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + urd = dev_get_drvdata(&cdev->dev); + if (urd) + urdev_get(urd); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + return urd; +} + +static struct urdev *urdev_get_from_devno(u16 devno) +{ + char bus_id[16]; + struct ccw_device *cdev; + struct urdev *urd; + + sprintf(bus_id, "0.0.%04x", devno); + cdev = get_ccwdev_by_busid(&ur_driver, bus_id); + if (!cdev) + return NULL; + urd = urdev_get_from_cdev(cdev); + put_device(&cdev->dev); + return urd; +} + +static void urdev_put(struct urdev *urd) +{ + if (refcount_dec_and_test(&urd->ref_count)) + urdev_free(urd); +} + +/* + * State and contents of ur devices can be changed by class D users issuing + * CP commands such as PURGE or TRANSFER, while the Linux guest is suspended. + * Also the Linux guest might be logged off, which causes all active spool + * files to be closed. + * So we cannot guarantee that spool files are still the same when the Linux + * guest is resumed. In order to avoid unpredictable results at resume time + * we simply refuse to suspend if a ur device node is open. + */ +static int ur_pm_suspend(struct ccw_device *cdev) +{ + struct urdev *urd = dev_get_drvdata(&cdev->dev); + + TRACE("ur_pm_suspend: cdev=%p\n", cdev); + if (urd->open_flag) { + pr_err("Unit record device %s is busy, %s refusing to " + "suspend.\n", dev_name(&cdev->dev), ur_banner); + return -EBUSY; + } + return 0; +} + +/* + * Low-level functions to do I/O to a ur device. + * alloc_chan_prog + * free_chan_prog + * do_ur_io + * ur_int_handler + * + * alloc_chan_prog allocates and builds the channel program + * free_chan_prog frees memory of 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. + */ + +static void free_chan_prog(struct ccw1 *cpa) +{ + struct ccw1 *ptr = cpa; + + while (ptr->cda) { + kfree((void *)(addr_t) ptr->cda); + ptr++; + } + kfree(cpa); +} + +/* + * 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. + */ +static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count, + int reclen) +{ + struct ccw1 *cpa; + void *kbuf; + int i; + + TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_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. + */ + cpa = kcalloc(rec_count + 1, sizeof(struct ccw1), + GFP_KERNEL | GFP_DMA); + if (!cpa) + return ERR_PTR(-ENOMEM); + + for (i = 0; i < rec_count; i++) { + cpa[i].cmd_code = WRITE_CCW_CMD; + cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI; + cpa[i].count = reclen; + kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA); + if (!kbuf) { + free_chan_prog(cpa); + return ERR_PTR(-ENOMEM); + } + cpa[i].cda = (u32)(addr_t) kbuf; + if (copy_from_user(kbuf, ubuf, reclen)) { + free_chan_prog(cpa); + return ERR_PTR(-EFAULT); + } + ubuf += reclen; + } + /* The following NOP CCW forces CE+DE to be presented together */ + cpa[i].cmd_code = CCW_CMD_NOOP; + return cpa; +} + +static int do_ur_io(struct urdev *urd, struct ccw1 *cpa) +{ + int rc; + struct ccw_device *cdev = urd->cdev; + DECLARE_COMPLETION_ONSTACK(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; + + if (!IS_ERR(irb)) { + TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n", + intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat, + irb->scsw.cmd.count); + } + if (!intparm) { + TRACE("ur_int_handler: unsolicited interrupt\n"); + return; + } + urd = dev_get_drvdata(&cdev->dev); + BUG_ON(!urd); + /* On special conditions irb is an error pointer */ + if (IS_ERR(irb)) + urd->io_request_rc = PTR_ERR(irb); + else if (irb->scsw.cmd.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; + int rc; + + urd = urdev_get_from_cdev(to_ccwdev(dev)); + if (!urd) + return -ENODEV; + rc = sprintf(buf, "%zu\n", urd->reclen); + urdev_put(urd); + return rc; +} + +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 -EOPNOTSUPP; + 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; + int rc; + + cpa = alloc_chan_prog(udata, count / reclen, reclen); + if (IS_ERR(cpa)) + return PTR_ERR(cpa); + + 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: + free_chan_prog(cpa); + 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); +} + +/* + * 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 = diag14(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 = diag14((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 = (char *) __get_free_page(GFP_KERNEL | GFP_DMA); + 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 && (copied == 0) && (*offs < PAGE_SIZE)) + *((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: + free_page((unsigned long) 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 = diag14((unsigned long) buf, spid, 0xfff); + switch (cc) { + case 0: + return 0; + default: + return -ENODATA; + } +} + +static int verify_uri_device(struct urdev *urd) +{ + struct file_control_block *fcb; + char *buf; + int rc; + + fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA); + if (!fcb) + return -ENOMEM; + + /* check for empty reader device (beginning of chain) */ + rc = diag_read_next_file_info(fcb, 0); + if (rc) + goto fail_free_fcb; + + /* if file is in hold status, we do not read it */ + if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) { + rc = -EPERM; + goto fail_free_fcb; + } + + /* open file on virtual reader */ + buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA); + if (!buf) { + rc = -ENOMEM; + goto fail_free_fcb; + } + rc = diag_read_file(urd->dev_id.devno, buf); + if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */ + goto fail_free_buf; + + /* check if the file on top of the queue is open now */ + rc = diag_read_next_file_info(fcb, 0); + if (rc) + goto fail_free_buf; + if (!(fcb->file_stat & FLG_IN_USE)) { + rc = -EMFILE; + goto fail_free_buf; + } + rc = 0; + +fail_free_buf: + free_page((unsigned long) buf); +fail_free_fcb: + kfree(fcb); + return rc; +} + +static int verify_device(struct urdev *urd) +{ + switch (urd->class) { + case DEV_CLASS_UR_O: + return 0; /* no check needed here */ + case DEV_CLASS_UR_I: + return verify_uri_device(urd); + default: + return -EOPNOTSUPP; + } +} + +static int get_uri_file_reclen(struct urdev *urd) +{ + struct file_control_block *fcb; + int rc; + + fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA); + if (!fcb) + return -ENOMEM; + rc = diag_read_next_file_info(fcb, 0); + if (rc) + goto fail_free; + if (fcb->file_stat & FLG_CP_DUMP) + rc = 0; + else + rc = fcb->rec_len; + +fail_free: + kfree(fcb); + return rc; +} + +static int get_file_reclen(struct urdev *urd) +{ + switch (urd->class) { + case DEV_CLASS_UR_O: + return 0; + case DEV_CLASS_UR_I: + return get_uri_file_reclen(urd); + default: + return -EOPNOTSUPP; + } +} + +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_inode(file)->i_rdev); + + urd = urdev_get_from_devno(devno); + if (!urd) { + rc = -ENXIO; + goto out; + } + + spin_lock(&urd->open_lock); + while (urd->open_flag) { + spin_unlock(&urd->open_lock); + if (file->f_flags & O_NONBLOCK) { + rc = -EBUSY; + goto fail_put; + } + if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) { + rc = -ERESTARTSYS; + goto fail_put; + } + spin_lock(&urd->open_lock); + } + urd->open_flag++; + spin_unlock(&urd->open_lock); + + 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: + spin_lock(&urd->open_lock); + urd->open_flag--; + spin_unlock(&urd->open_lock); +fail_put: + urdev_put(urd); +out: + return rc; +} + +static int ur_release(struct inode *inode, struct file *file) +{ + struct urfile *urf = file->private_data; + + TRACE("ur_release\n"); + spin_lock(&urf->urd->open_lock); + urf->urd->open_flag--; + spin_unlock(&urf->urd->open_lock); + wake_up_interruptible(&urf->urd->wait); + urdev_put(urf->urd); + urfile_free(urf); + return 0; +} + +static loff_t ur_llseek(struct file *file, loff_t offset, int whence) +{ + 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 */ + return no_seek_end_llseek(file, offset, whence); +} + +static const 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 creates the struct urdev (with refcount = 1), the device + * attributes, sets up the interrupt handler and validates the virtual + * unit record device. + * ur_remove removes the device attributes and drops the reference to + * struct urdev. + * + * ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized + * by the vmur_mutex lock. + * + * urd->char_device is used as indication that the online function has + * been completed successfully. + */ +static int ur_probe(struct ccw_device *cdev) +{ + struct urdev *urd; + int rc; + + TRACE("ur_probe: cdev=%p\n", cdev); + + mutex_lock(&vmur_mutex); + urd = urdev_alloc(cdev); + if (!urd) { + rc = -ENOMEM; + goto fail_unlock; + } + + rc = ur_create_attributes(&cdev->dev); + if (rc) { + rc = -ENOMEM; + goto fail_urdev_put; + } + 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_remove_attr; + } + if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) { + rc = -EOPNOTSUPP; + goto fail_remove_attr; + } + spin_lock_irq(get_ccwdev_lock(cdev)); + dev_set_drvdata(&cdev->dev, urd); + spin_unlock_irq(get_ccwdev_lock(cdev)); + + mutex_unlock(&vmur_mutex); + return 0; + +fail_remove_attr: + ur_remove_attributes(&cdev->dev); +fail_urdev_put: + urdev_put(urd); +fail_unlock: + mutex_unlock(&vmur_mutex); + return rc; +} + +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\n", cdev); + + mutex_lock(&vmur_mutex); + urd = urdev_get_from_cdev(cdev); + if (!urd) { + /* ur_remove already deleted our urd */ + rc = -ENODEV; + goto fail_unlock; + } + + if (urd->char_device) { + /* Another ur_set_online was faster */ + rc = -EBUSY; + goto fail_urdev_put; + } + + 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_urdev_put; + } + + urd->char_device->ops = &ur_fops; + urd->char_device->owner = ur_fops.owner; + + rc = cdev_add(urd->char_device, MKDEV(major, minor), 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", dev_name(&cdev->dev)); + if (urd->class == DEV_CLASS_UR_O) + sprintf(node_id, "vmpun-%s", dev_name(&cdev->dev)); + } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) { + sprintf(node_id, "vmprt-%s", dev_name(&cdev->dev)); + } else { + rc = -EOPNOTSUPP; + goto fail_free_cdev; + } + + urd->device = device_create(vmur_class, &cdev->dev, + urd->char_device->dev, NULL, "%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; + } + urdev_put(urd); + mutex_unlock(&vmur_mutex); + return 0; + +fail_free_cdev: + cdev_del(urd->char_device); + urd->char_device = NULL; +fail_urdev_put: + urdev_put(urd); +fail_unlock: + mutex_unlock(&vmur_mutex); + return rc; +} + +static int ur_set_offline_force(struct ccw_device *cdev, int force) +{ + struct urdev *urd; + int rc; + + TRACE("ur_set_offline: cdev=%p\n", cdev); + urd = urdev_get_from_cdev(cdev); + if (!urd) + /* ur_remove already deleted our urd */ + return -ENODEV; + if (!urd->char_device) { + /* Another ur_set_offline was faster */ + rc = -EBUSY; + goto fail_urdev_put; + } + if (!force && (refcount_read(&urd->ref_count) > 2)) { + /* There is still a user of urd (e.g. ur_open) */ + TRACE("ur_set_offline: BUSY\n"); + rc = -EBUSY; + goto fail_urdev_put; + } + device_destroy(vmur_class, urd->char_device->dev); + cdev_del(urd->char_device); + urd->char_device = NULL; + rc = 0; + +fail_urdev_put: + urdev_put(urd); + return rc; +} + +static int ur_set_offline(struct ccw_device *cdev) +{ + int rc; + + mutex_lock(&vmur_mutex); + rc = ur_set_offline_force(cdev, 0); + mutex_unlock(&vmur_mutex); + return rc; +} + +static void ur_remove(struct ccw_device *cdev) +{ + unsigned long flags; + + TRACE("ur_remove\n"); + + mutex_lock(&vmur_mutex); + + if (cdev->online) + ur_set_offline_force(cdev, 1); + ur_remove_attributes(&cdev->dev); + + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + urdev_put(dev_get_drvdata(&cdev->dev)); + dev_set_drvdata(&cdev->dev, NULL); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + + mutex_unlock(&vmur_mutex); +} + +/* + * Module initialisation and cleanup + */ +static int __init ur_init(void) +{ + int rc; + dev_t dev; + + if (!MACHINE_IS_VM) { + pr_err("The %s cannot be loaded without 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); + + vmur_class = class_create(THIS_MODULE, "vmur"); + if (IS_ERR(vmur_class)) { + rc = PTR_ERR(vmur_class); + goto fail_free_dbf; + } + + rc = ccw_driver_register(&ur_driver); + if (rc) + goto fail_class_destroy; + + rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur"); + if (rc) { + pr_err("Kernel function alloc_chrdev_region failed with " + "error code %d\n", rc); + goto fail_unregister_driver; + } + ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0); + + pr_info("%s loaded.\n", ur_banner); + return 0; + +fail_unregister_driver: + ccw_driver_unregister(&ur_driver); +fail_class_destroy: + class_destroy(vmur_class); +fail_free_dbf: + debug_unregister(vmur_dbf); + return rc; +} + +static void __exit ur_exit(void) +{ + unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS); + ccw_driver_unregister(&ur_driver); + class_destroy(vmur_class); + debug_unregister(vmur_dbf); + pr_info("%s unloaded.\n", ur_banner); +} + +module_init(ur_init); +module_exit(ur_exit); |