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linux/drivers/s390/cio/device.c
Heiko Carstens 292888c81e [S390] cio: kernel stack overflow. 
Use different kind of assignment to make sure gcc doesn't create code
that creates temp variables on the stack, assigns values to it and
copies the content of the whole temp variable to the destination.
This reduces stack usage of e.g. ccwgroup_driver_register from 976
to 48 bytes instead.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-08-30 14:33:35 +02:00

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/*
* drivers/s390/cio/device.c
* bus driver for ccw devices
*
* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
* IBM Corporation
* Author(s): Arnd Bergmann (arndb@de.ibm.com)
* Cornelia Huck (cornelia.huck@de.ibm.com)
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/workqueue.h>
#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/param.h> /* HZ */
#include "cio.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"
/******************* bus type handling ***********************/
/* The Linux driver model distinguishes between a bus type and
* the bus itself. Of course we only have one channel
* subsystem driver and one channel system per machine, but
* we still use the abstraction. T.R. says it's a good idea. */
static int
ccw_bus_match (struct device * dev, struct device_driver * drv)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_driver *cdrv = to_ccwdrv(drv);
const struct ccw_device_id *ids = cdrv->ids, *found;
if (!ids)
return 0;
found = ccw_device_id_match(ids, &cdev->id);
if (!found)
return 0;
cdev->id.driver_info = found->driver_info;
return 1;
}
/*
* Hotplugging interface for ccw devices.
* Heavily modeled on pci and usb hotplug.
*/
static int
ccw_uevent (struct device *dev, char **envp, int num_envp,
char *buffer, int buffer_size)
{
struct ccw_device *cdev = to_ccwdev(dev);
int i = 0;
int length = 0;
if (!cdev)
return -ENODEV;
/* what we want to pass to /sbin/hotplug */
envp[i++] = buffer;
length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
cdev->id.cu_type);
if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
++length;
buffer += length;
envp[i++] = buffer;
length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
cdev->id.cu_model);
if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
++length;
buffer += length;
/* The next two can be zero, that's ok for us */
envp[i++] = buffer;
length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
cdev->id.dev_type);
if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
++length;
buffer += length;
envp[i++] = buffer;
length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
cdev->id.dev_model);
if ((buffer_size - length <= 0) || (i >= num_envp))
return -ENOMEM;
envp[i] = NULL;
return 0;
}
struct bus_type ccw_bus_type;
static int io_subchannel_probe (struct subchannel *);
static int io_subchannel_remove (struct subchannel *);
void io_subchannel_irq (struct device *);
static int io_subchannel_notify(struct device *, int);
static void io_subchannel_verify(struct device *);
static void io_subchannel_ioterm(struct device *);
static void io_subchannel_shutdown(struct subchannel *);
struct css_driver io_subchannel_driver = {
.subchannel_type = SUBCHANNEL_TYPE_IO,
.drv = {
.name = "io_subchannel",
.bus = &css_bus_type,
},
.irq = io_subchannel_irq,
.notify = io_subchannel_notify,
.verify = io_subchannel_verify,
.termination = io_subchannel_ioterm,
.probe = io_subchannel_probe,
.remove = io_subchannel_remove,
.shutdown = io_subchannel_shutdown,
};
struct workqueue_struct *ccw_device_work;
struct workqueue_struct *ccw_device_notify_work;
wait_queue_head_t ccw_device_init_wq;
atomic_t ccw_device_init_count;
static int __init
init_ccw_bus_type (void)
{
int ret;
init_waitqueue_head(&ccw_device_init_wq);
atomic_set(&ccw_device_init_count, 0);
ccw_device_work = create_singlethread_workqueue("cio");
if (!ccw_device_work)
return -ENOMEM; /* FIXME: better errno ? */
ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
if (!ccw_device_notify_work) {
ret = -ENOMEM; /* FIXME: better errno ? */
goto out_err;
}
slow_path_wq = create_singlethread_workqueue("kslowcrw");
if (!slow_path_wq) {
ret = -ENOMEM; /* FIXME: better errno ? */
goto out_err;
}
if ((ret = bus_register (&ccw_bus_type)))
goto out_err;
if ((ret = driver_register(&io_subchannel_driver.drv)))
goto out_err;
wait_event(ccw_device_init_wq,
atomic_read(&ccw_device_init_count) == 0);
flush_workqueue(ccw_device_work);
return 0;
out_err:
if (ccw_device_work)
destroy_workqueue(ccw_device_work);
if (ccw_device_notify_work)
destroy_workqueue(ccw_device_notify_work);
if (slow_path_wq)
destroy_workqueue(slow_path_wq);
return ret;
}
static void __exit
cleanup_ccw_bus_type (void)
{
driver_unregister(&io_subchannel_driver.drv);
bus_unregister(&ccw_bus_type);
destroy_workqueue(ccw_device_notify_work);
destroy_workqueue(ccw_device_work);
}
subsys_initcall(init_ccw_bus_type);
module_exit(cleanup_ccw_bus_type);
/************************ device handling **************************/
/*
* A ccw_device has some interfaces in sysfs in addition to the
* standard ones.
* The following entries are designed to export the information which
* resided in 2.4 in /proc/subchannels. Subchannel and device number
* are obvious, so they don't have an entry :)
* TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
*/
static ssize_t
chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
{
struct subchannel *sch = to_subchannel(dev);
struct ssd_info *ssd = &sch->ssd_info;
ssize_t ret = 0;
int chp;
for (chp = 0; chp < 8; chp++)
ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
ret += sprintf (buf+ret, "\n");
return min((ssize_t)PAGE_SIZE, ret);
}
static ssize_t
pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
{
struct subchannel *sch = to_subchannel(dev);
struct pmcw *pmcw = &sch->schib.pmcw;
return sprintf (buf, "%02x %02x %02x\n",
pmcw->pim, pmcw->pam, pmcw->pom);
}
static ssize_t
devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_device_id *id = &(cdev->id);
if (id->dev_type != 0)
return sprintf(buf, "%04x/%02x\n",
id->dev_type, id->dev_model);
else
return sprintf(buf, "n/a\n");
}
static ssize_t
cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_device_id *id = &(cdev->id);
return sprintf(buf, "%04x/%02x\n",
id->cu_type, id->cu_model);
}
static ssize_t
modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_device_id *id = &(cdev->id);
int ret;
ret = sprintf(buf, "ccw:t%04Xm%02X",
id->cu_type, id->cu_model);
if (id->dev_type != 0)
ret += sprintf(buf + ret, "dt%04Xdm%02X\n",
id->dev_type, id->dev_model);
else
ret += sprintf(buf + ret, "dtdm\n");
return ret;
}
static ssize_t
online_show (struct device *dev, struct device_attribute *attr, char *buf)
{
struct ccw_device *cdev = to_ccwdev(dev);
return sprintf(buf, cdev->online ? "1\n" : "0\n");
}
static void
ccw_device_remove_disconnected(struct ccw_device *cdev)
{
struct subchannel *sch;
/*
* Forced offline in disconnected state means
* 'throw away device'.
*/
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
sch->schib.pmcw.intparm = 0;
cio_modify(sch);
put_device(&sch->dev);
}
int
ccw_device_set_offline(struct ccw_device *cdev)
{
int ret;
if (!cdev)
return -ENODEV;
if (!cdev->online || !cdev->drv)
return -EINVAL;
if (cdev->drv->set_offline) {
ret = cdev->drv->set_offline(cdev);
if (ret != 0)
return ret;
}
cdev->online = 0;
spin_lock_irq(cdev->ccwlock);
ret = ccw_device_offline(cdev);
if (ret == -ENODEV) {
if (cdev->private->state != DEV_STATE_NOT_OPER) {
cdev->private->state = DEV_STATE_OFFLINE;
dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
}
spin_unlock_irq(cdev->ccwlock);
return ret;
}
spin_unlock_irq(cdev->ccwlock);
if (ret == 0)
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
else {
pr_debug("ccw_device_offline returned %d, device %s\n",
ret, cdev->dev.bus_id);
cdev->online = 1;
}
return ret;
}
int
ccw_device_set_online(struct ccw_device *cdev)
{
int ret;
if (!cdev)
return -ENODEV;
if (cdev->online || !cdev->drv)
return -EINVAL;
spin_lock_irq(cdev->ccwlock);
ret = ccw_device_online(cdev);
spin_unlock_irq(cdev->ccwlock);
if (ret == 0)
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
else {
pr_debug("ccw_device_online returned %d, device %s\n",
ret, cdev->dev.bus_id);
return ret;
}
if (cdev->private->state != DEV_STATE_ONLINE)
return -ENODEV;
if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
cdev->online = 1;
return 0;
}
spin_lock_irq(cdev->ccwlock);
ret = ccw_device_offline(cdev);
spin_unlock_irq(cdev->ccwlock);
if (ret == 0)
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
else
pr_debug("ccw_device_offline returned %d, device %s\n",
ret, cdev->dev.bus_id);
return (ret == 0) ? -ENODEV : ret;
}
static ssize_t
online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
struct ccw_device *cdev = to_ccwdev(dev);
int i, force, ret;
char *tmp;
if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
return -EAGAIN;
if (cdev->drv && !try_module_get(cdev->drv->owner)) {
atomic_set(&cdev->private->onoff, 0);
return -EINVAL;
}
if (!strncmp(buf, "force\n", count)) {
force = 1;
i = 1;
} else {
force = 0;
i = simple_strtoul(buf, &tmp, 16);
}
if (i == 1) {
/* Do device recognition, if needed. */
if (cdev->id.cu_type == 0) {
ret = ccw_device_recognition(cdev);
if (ret) {
printk(KERN_WARNING"Couldn't start recognition "
"for device %s (ret=%d)\n",
cdev->dev.bus_id, ret);
goto out;
}
wait_event(cdev->private->wait_q,
cdev->private->flags.recog_done);
}
if (cdev->drv && cdev->drv->set_online)
ccw_device_set_online(cdev);
} else if (i == 0) {
if (cdev->private->state == DEV_STATE_DISCONNECTED)
ccw_device_remove_disconnected(cdev);
else if (cdev->drv && cdev->drv->set_offline)
ccw_device_set_offline(cdev);
}
if (force && cdev->private->state == DEV_STATE_BOXED) {
ret = ccw_device_stlck(cdev);
if (ret) {
printk(KERN_WARNING"ccw_device_stlck for device %s "
"returned %d!\n", cdev->dev.bus_id, ret);
goto out;
}
/* Do device recognition, if needed. */
if (cdev->id.cu_type == 0) {
cdev->private->state = DEV_STATE_NOT_OPER;
ret = ccw_device_recognition(cdev);
if (ret) {
printk(KERN_WARNING"Couldn't start recognition "
"for device %s (ret=%d)\n",
cdev->dev.bus_id, ret);
goto out;
}
wait_event(cdev->private->wait_q,
cdev->private->flags.recog_done);
}
if (cdev->drv && cdev->drv->set_online)
ccw_device_set_online(cdev);
}
out:
if (cdev->drv)
module_put(cdev->drv->owner);
atomic_set(&cdev->private->onoff, 0);
return count;
}
static ssize_t
available_show (struct device *dev, struct device_attribute *attr, char *buf)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct subchannel *sch;
switch (cdev->private->state) {
case DEV_STATE_BOXED:
return sprintf(buf, "boxed\n");
case DEV_STATE_DISCONNECTED:
case DEV_STATE_DISCONNECTED_SENSE_ID:
case DEV_STATE_NOT_OPER:
sch = to_subchannel(dev->parent);
if (!sch->lpm)
return sprintf(buf, "no path\n");
else
return sprintf(buf, "no device\n");
default:
/* All other states considered fine. */
return sprintf(buf, "good\n");
}
}
static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
static DEVICE_ATTR(online, 0644, online_show, online_store);
extern struct device_attribute dev_attr_cmb_enable;
static DEVICE_ATTR(availability, 0444, available_show, NULL);
static struct attribute * subch_attrs[] = {
&dev_attr_chpids.attr,
&dev_attr_pimpampom.attr,
NULL,
};
static struct attribute_group subch_attr_group = {
.attrs = subch_attrs,
};
static inline int
subchannel_add_files (struct device *dev)
{
return sysfs_create_group(&dev->kobj, &subch_attr_group);
}
static struct attribute * ccwdev_attrs[] = {
&dev_attr_devtype.attr,
&dev_attr_cutype.attr,
&dev_attr_modalias.attr,
&dev_attr_online.attr,
&dev_attr_cmb_enable.attr,
&dev_attr_availability.attr,
NULL,
};
static struct attribute_group ccwdev_attr_group = {
.attrs = ccwdev_attrs,
};
static inline int
device_add_files (struct device *dev)
{
return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
}
static inline void
device_remove_files(struct device *dev)
{
sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
}
/* this is a simple abstraction for device_register that sets the
* correct bus type and adds the bus specific files */
int
ccw_device_register(struct ccw_device *cdev)
{
struct device *dev = &cdev->dev;
int ret;
dev->bus = &ccw_bus_type;
if ((ret = device_add(dev)))
return ret;
set_bit(1, &cdev->private->registered);
if ((ret = device_add_files(dev))) {
if (test_and_clear_bit(1, &cdev->private->registered))
device_del(dev);
}
return ret;
}
struct match_data {
unsigned int devno;
unsigned int ssid;
struct ccw_device * sibling;
};
static int
match_devno(struct device * dev, void * data)
{
struct match_data * d = (struct match_data *)data;
struct ccw_device * cdev;
cdev = to_ccwdev(dev);
if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
(cdev->private->devno == d->devno) &&
(cdev->private->ssid == d->ssid) &&
(cdev != d->sibling)) {
cdev->private->state = DEV_STATE_NOT_OPER;
return 1;
}
return 0;
}
static struct ccw_device *
get_disc_ccwdev_by_devno(unsigned int devno, unsigned int ssid,
struct ccw_device *sibling)
{
struct device *dev;
struct match_data data;
data.devno = devno;
data.ssid = ssid;
data.sibling = sibling;
dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
return dev ? to_ccwdev(dev) : NULL;
}
static void
ccw_device_add_changed(void *data)
{
struct ccw_device *cdev;
cdev = (struct ccw_device *)data;
if (device_add(&cdev->dev)) {
put_device(&cdev->dev);
return;
}
set_bit(1, &cdev->private->registered);
if (device_add_files(&cdev->dev)) {
if (test_and_clear_bit(1, &cdev->private->registered))
device_unregister(&cdev->dev);
}
}
extern int css_get_ssd_info(struct subchannel *sch);
void
ccw_device_do_unreg_rereg(void *data)
{
struct ccw_device *cdev;
struct subchannel *sch;
int need_rename;
cdev = (struct ccw_device *)data;
sch = to_subchannel(cdev->dev.parent);
if (cdev->private->devno != sch->schib.pmcw.dev) {
/*
* The device number has changed. This is usually only when
* a device has been detached under VM and then re-appeared
* on another subchannel because of a different attachment
* order than before. Ideally, we should should just switch
* subchannels, but unfortunately, this is not possible with
* the current implementation.
* Instead, we search for the old subchannel for this device
* number and deregister so there are no collisions with the
* newly registered ccw_device.
* FIXME: Find another solution so the block layer doesn't
* get possibly sick...
*/
struct ccw_device *other_cdev;
need_rename = 1;
other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
sch->schid.ssid, cdev);
if (other_cdev) {
struct subchannel *other_sch;
other_sch = to_subchannel(other_cdev->dev.parent);
if (get_device(&other_sch->dev)) {
stsch(other_sch->schid, &other_sch->schib);
if (other_sch->schib.pmcw.dnv) {
other_sch->schib.pmcw.intparm = 0;
cio_modify(other_sch);
}
css_sch_device_unregister(other_sch);
}
}
/* Update ssd info here. */
css_get_ssd_info(sch);
cdev->private->devno = sch->schib.pmcw.dev;
} else
need_rename = 0;
device_remove_files(&cdev->dev);
if (test_and_clear_bit(1, &cdev->private->registered))
device_del(&cdev->dev);
if (need_rename)
snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
sch->schid.ssid, sch->schib.pmcw.dev);
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_add_changed, (void *)cdev);
queue_work(ccw_device_work, &cdev->private->kick_work);
}
static void
ccw_device_release(struct device *dev)
{
struct ccw_device *cdev;
cdev = to_ccwdev(dev);
kfree(cdev->private);
kfree(cdev);
}
/*
* Register recognized device.
*/
static void
io_subchannel_register(void *data)
{
struct ccw_device *cdev;
struct subchannel *sch;
int ret;
unsigned long flags;
cdev = (struct ccw_device *) data;
sch = to_subchannel(cdev->dev.parent);
if (klist_node_attached(&cdev->dev.knode_parent)) {
bus_rescan_devices(&ccw_bus_type);
goto out;
}
/* make it known to the system */
ret = ccw_device_register(cdev);
if (ret) {
printk (KERN_WARNING "%s: could not register %s\n",
__func__, cdev->dev.bus_id);
put_device(&cdev->dev);
spin_lock_irqsave(&sch->lock, flags);
sch->dev.driver_data = NULL;
spin_unlock_irqrestore(&sch->lock, flags);
kfree (cdev->private);
kfree (cdev);
put_device(&sch->dev);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
return;
}
ret = subchannel_add_files(cdev->dev.parent);
if (ret)
printk(KERN_WARNING "%s: could not add attributes to %s\n",
__func__, sch->dev.bus_id);
put_device(&cdev->dev);
out:
cdev->private->flags.recog_done = 1;
put_device(&sch->dev);
wake_up(&cdev->private->wait_q);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
}
void
ccw_device_call_sch_unregister(void *data)
{
struct ccw_device *cdev = data;
struct subchannel *sch;
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
sch->schib.pmcw.intparm = 0;
cio_modify(sch);
put_device(&cdev->dev);
put_device(&sch->dev);
}
/*
* subchannel recognition done. Called from the state machine.
*/
void
io_subchannel_recog_done(struct ccw_device *cdev)
{
struct subchannel *sch;
if (css_init_done == 0) {
cdev->private->flags.recog_done = 1;
return;
}
switch (cdev->private->state) {
case DEV_STATE_NOT_OPER:
cdev->private->flags.recog_done = 1;
/* Remove device found not operational. */
if (!get_device(&cdev->dev))
break;
sch = to_subchannel(cdev->dev.parent);
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_call_sch_unregister, (void *) cdev);
queue_work(slow_path_wq, &cdev->private->kick_work);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
break;
case DEV_STATE_BOXED:
/* Device did not respond in time. */
case DEV_STATE_OFFLINE:
/*
* We can't register the device in interrupt context so
* we schedule a work item.
*/
if (!get_device(&cdev->dev))
break;
PREPARE_WORK(&cdev->private->kick_work,
io_subchannel_register, (void *) cdev);
queue_work(slow_path_wq, &cdev->private->kick_work);
break;
}
}
static int
io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
{
int rc;
struct ccw_device_private *priv;
sch->dev.driver_data = cdev;
sch->driver = &io_subchannel_driver;
cdev->ccwlock = &sch->lock;
/* Init private data. */
priv = cdev->private;
priv->devno = sch->schib.pmcw.dev;
priv->ssid = sch->schid.ssid;
priv->sch_no = sch->schid.sch_no;
priv->state = DEV_STATE_NOT_OPER;
INIT_LIST_HEAD(&priv->cmb_list);
init_waitqueue_head(&priv->wait_q);
init_timer(&priv->timer);
/* Set an initial name for the device. */
snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
sch->schid.ssid, sch->schib.pmcw.dev);
/* Increase counter of devices currently in recognition. */
atomic_inc(&ccw_device_init_count);
/* Start async. device sensing. */
spin_lock_irq(&sch->lock);
rc = ccw_device_recognition(cdev);
spin_unlock_irq(&sch->lock);
if (rc) {
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
}
return rc;
}
static int
io_subchannel_probe (struct subchannel *sch)
{
struct ccw_device *cdev;
int rc;
unsigned long flags;
if (sch->dev.driver_data) {
/*
* This subchannel already has an associated ccw_device.
* Register it and exit. This happens for all early
* device, e.g. the console.
*/
cdev = sch->dev.driver_data;
device_initialize(&cdev->dev);
ccw_device_register(cdev);
subchannel_add_files(&sch->dev);
/*
* Check if the device is already online. If it is
* the reference count needs to be corrected
* (see ccw_device_online and css_init_done for the
* ugly details).
*/
if (cdev->private->state != DEV_STATE_NOT_OPER &&
cdev->private->state != DEV_STATE_OFFLINE &&
cdev->private->state != DEV_STATE_BOXED)
get_device(&cdev->dev);
return 0;
}
cdev = kzalloc (sizeof(*cdev), GFP_KERNEL);
if (!cdev)
return -ENOMEM;
cdev->private = kzalloc(sizeof(struct ccw_device_private),
GFP_KERNEL | GFP_DMA);
if (!cdev->private) {
kfree(cdev);
return -ENOMEM;
}
atomic_set(&cdev->private->onoff, 0);
cdev->dev.parent = &sch->dev;
cdev->dev.release = ccw_device_release;
INIT_LIST_HEAD(&cdev->private->kick_work.entry);
/* Do first half of device_register. */
device_initialize(&cdev->dev);
if (!get_device(&sch->dev)) {
if (cdev->dev.release)
cdev->dev.release(&cdev->dev);
return -ENODEV;
}
rc = io_subchannel_recog(cdev, sch);
if (rc) {
spin_lock_irqsave(&sch->lock, flags);
sch->dev.driver_data = NULL;
spin_unlock_irqrestore(&sch->lock, flags);
if (cdev->dev.release)
cdev->dev.release(&cdev->dev);
}
return rc;
}
static void
ccw_device_unregister(void *data)
{
struct ccw_device *cdev;
cdev = (struct ccw_device *)data;
if (test_and_clear_bit(1, &cdev->private->registered))
device_unregister(&cdev->dev);
put_device(&cdev->dev);
}
static int
io_subchannel_remove (struct subchannel *sch)
{
struct ccw_device *cdev;
unsigned long flags;
if (!sch->dev.driver_data)
return 0;
cdev = sch->dev.driver_data;
/* Set ccw device to not operational and drop reference. */
spin_lock_irqsave(cdev->ccwlock, flags);
sch->dev.driver_data = NULL;
cdev->private->state = DEV_STATE_NOT_OPER;
spin_unlock_irqrestore(cdev->ccwlock, flags);
/*
* Put unregistration on workqueue to avoid livelocks on the css bus
* semaphore.
*/
if (get_device(&cdev->dev)) {
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_unregister, (void *) cdev);
queue_work(ccw_device_work, &cdev->private->kick_work);
}
return 0;
}
static int
io_subchannel_notify(struct device *dev, int event)
{
struct ccw_device *cdev;
cdev = dev->driver_data;
if (!cdev)
return 0;
if (!cdev->drv)
return 0;
if (!cdev->online)
return 0;
return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
}
static void
io_subchannel_verify(struct device *dev)
{
struct ccw_device *cdev;
cdev = dev->driver_data;
if (cdev)
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
}
static void
io_subchannel_ioterm(struct device *dev)
{
struct ccw_device *cdev;
cdev = dev->driver_data;
if (!cdev)
return;
cdev->private->state = DEV_STATE_CLEAR_VERIFY;
if (cdev->handler)
cdev->handler(cdev, cdev->private->intparm,
ERR_PTR(-EIO));
}
static void
io_subchannel_shutdown(struct subchannel *sch)
{
struct ccw_device *cdev;
int ret;
cdev = sch->dev.driver_data;
if (cio_is_console(sch->schid))
return;
if (!sch->schib.pmcw.ena)
/* Nothing to do. */
return;
ret = cio_disable_subchannel(sch);
if (ret != -EBUSY)
/* Subchannel is disabled, we're done. */
return;
cdev->private->state = DEV_STATE_QUIESCE;
if (cdev->handler)
cdev->handler(cdev, cdev->private->intparm,
ERR_PTR(-EIO));
ret = ccw_device_cancel_halt_clear(cdev);
if (ret == -EBUSY) {
ccw_device_set_timeout(cdev, HZ/10);
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
}
cio_disable_subchannel(sch);
}
#ifdef CONFIG_CCW_CONSOLE
static struct ccw_device console_cdev;
static struct ccw_device_private console_private;
static int console_cdev_in_use;
static int
ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
{
int rc;
/* Initialize the ccw_device structure. */
cdev->dev.parent= &sch->dev;
rc = io_subchannel_recog(cdev, sch);
if (rc)
return rc;
/* Now wait for the async. recognition to come to an end. */
spin_lock_irq(cdev->ccwlock);
while (!dev_fsm_final_state(cdev))
wait_cons_dev();
rc = -EIO;
if (cdev->private->state != DEV_STATE_OFFLINE)
goto out_unlock;
ccw_device_online(cdev);
while (!dev_fsm_final_state(cdev))
wait_cons_dev();
if (cdev->private->state != DEV_STATE_ONLINE)
goto out_unlock;
rc = 0;
out_unlock:
spin_unlock_irq(cdev->ccwlock);
return 0;
}
struct ccw_device *
ccw_device_probe_console(void)
{
struct subchannel *sch;
int ret;
if (xchg(&console_cdev_in_use, 1) != 0)
return ERR_PTR(-EBUSY);
sch = cio_probe_console();
if (IS_ERR(sch)) {
console_cdev_in_use = 0;
return (void *) sch;
}
memset(&console_cdev, 0, sizeof(struct ccw_device));
memset(&console_private, 0, sizeof(struct ccw_device_private));
console_cdev.private = &console_private;
ret = ccw_device_console_enable(&console_cdev, sch);
if (ret) {
cio_release_console();
console_cdev_in_use = 0;
return ERR_PTR(ret);
}
console_cdev.online = 1;
return &console_cdev;
}
#endif
/*
* get ccw_device matching the busid, but only if owned by cdrv
*/
static int
__ccwdev_check_busid(struct device *dev, void *id)
{
char *bus_id;
bus_id = (char *)id;
return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
}
struct ccw_device *
get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
{
struct device *dev;
struct device_driver *drv;
drv = get_driver(&cdrv->driver);
if (!drv)
return NULL;
dev = driver_find_device(drv, NULL, (void *)bus_id,
__ccwdev_check_busid);
put_driver(drv);
return dev ? to_ccwdev(dev) : NULL;
}
/************************** device driver handling ************************/
/* This is the implementation of the ccw_driver class. The probe, remove
* and release methods are initially very similar to the device_driver
* implementations, with the difference that they have ccw_device
* arguments.
*
* A ccw driver also contains the information that is needed for
* device matching.
*/
static int
ccw_device_probe (struct device *dev)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
int ret;
cdev->drv = cdrv; /* to let the driver call _set_online */
ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
if (ret) {
cdev->drv = NULL;
return ret;
}
return 0;
}
static int
ccw_device_remove (struct device *dev)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_driver *cdrv = cdev->drv;
int ret;
pr_debug("removing device %s\n", cdev->dev.bus_id);
if (cdrv->remove)
cdrv->remove(cdev);
if (cdev->online) {
cdev->online = 0;
spin_lock_irq(cdev->ccwlock);
ret = ccw_device_offline(cdev);
spin_unlock_irq(cdev->ccwlock);
if (ret == 0)
wait_event(cdev->private->wait_q,
dev_fsm_final_state(cdev));
else
//FIXME: we can't fail!
pr_debug("ccw_device_offline returned %d, device %s\n",
ret, cdev->dev.bus_id);
}
ccw_device_set_timeout(cdev, 0);
cdev->drv = NULL;
return 0;
}
struct bus_type ccw_bus_type = {
.name = "ccw",
.match = ccw_bus_match,
.uevent = ccw_uevent,
.probe = ccw_device_probe,
.remove = ccw_device_remove,
};
int
ccw_driver_register (struct ccw_driver *cdriver)
{
struct device_driver *drv = &cdriver->driver;
drv->bus = &ccw_bus_type;
drv->name = cdriver->name;
return driver_register(drv);
}
void
ccw_driver_unregister (struct ccw_driver *cdriver)
{
driver_unregister(&cdriver->driver);
}
/* Helper func for qdio. */
struct subchannel_id
ccw_device_get_subchannel_id(struct ccw_device *cdev)
{
struct subchannel *sch;
sch = to_subchannel(cdev->dev.parent);
return sch->schid;
}
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccw_device_set_online);
EXPORT_SYMBOL(ccw_device_set_offline);
EXPORT_SYMBOL(ccw_driver_register);
EXPORT_SYMBOL(ccw_driver_unregister);
EXPORT_SYMBOL(get_ccwdev_by_busid);
EXPORT_SYMBOL(ccw_bus_type);
EXPORT_SYMBOL(ccw_device_work);
EXPORT_SYMBOL(ccw_device_notify_work);
EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);
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