/*
* 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 <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");
#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,
};
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 the cdev->dev.driver_data pointer.
*
* urd references:
* - ur_probe gets a urd reference, ur_remove drops the reference
* (cdev->dev.driver_data)
* - ur_open gets a urd reference, ur_relase 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 cdev->dev.driver_data 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);
atomic_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)
{
atomic_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 = cdev->dev.driver_data;
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 (atomic_dec_and_test(&urd->ref_count))
urdev_free(urd);
}
/*
* 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 = kzalloc((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;
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;
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.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 -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;
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 -ENOTSUPP;
}
}
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 -ENOTSUPP;
}
}
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;
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);
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)
{
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 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 = -ENOTSUPP;
goto fail_remove_attr;
}
spin_lock_irq(get_ccwdev_lock(cdev));
cdev->dev.driver_data = 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;
}
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;
}
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 && (atomic_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(cdev->dev.driver_data);
cdev->dev.driver_data = 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) {
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);
