linux/drivers/s390/char/vmur.c
Michael Holzheu 3f7cb51fac [S390] vmur: Invalid allocation sequence for vmur class
The vmur class is allocated after the CCW driver is registered
and it is destroyed before the CCW driver is unregistered.
This is not the correct sequence, because the vmur class can be used
via driver core callbacks that are triggered during the CCW driver
deregistration. For Example:

1. vmur device is online
2. vmur module is unloaded

This leads to the following function call stack:

    <4> [<0000000000387286>] device_destroy+0x36/0x5c
    <4> [<000003e000209714>] ur_set_offline_force+0x9c/0x10c [vmur]
    <4> [<000003e00020a928>] ur_remove+0x64/0xbc [vmur]
    <4> [<00000000003e4d2e>] ccw_device_remove+0x42/0x1ac
    <4> [<000000000038a1aa>] __device_release_driver+0x9a/0xe4
    <4> [<000000000038a2da>] driver_detach+0xe6/0xec
    <4> [<0000000000388ee4>] bus_remove_driver+0xc0/0x108
    <4> [<000003e00020ad5a>] ur_exit+0x52/0x84 [vmur]

In device_destroy() the vmur class is used. Since it is already freed,
this can lead to a kernel panic.

To fix the problem, the vmur class has to be allocated before the CCW
driver is registered and destroyed after the CCW driver has ben unregistered.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11 10:29:49 +02:00

1069 lines
24 KiB
C

/*
* 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/smp_lock.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");
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 = {
.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,
};
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_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 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);
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 = 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 (atomic_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 = 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.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;
lock_kernel();
/*
* 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) {
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;
unlock_kernel();
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:
unlock_kernel();
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 = -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;
}
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", 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, NULL, 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 && (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(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);