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linux/drivers/s390/cio/device.c
Cornelia Huck fb6958a594 [PATCH] s390: multiple subchannel sets support 
Add support for multiple subchannel sets.  Works with arbitrary devices in
subchannel set 1 and is transparent to device drivers.  Although currently
only two subchannel sets are available, this will work with the architectured
maximum number of subchannel sets as well.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:52 -08:00

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/*
* drivers/s390/cio/device.c
* bus driver for ccw devices
* $Revision: 1.137 $
*
* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
* IBM Corporation
* Author(s): Arnd Bergmann (arndb@de.ibm.com)
* Cornelia Huck (cohuck@de.ibm.com)
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#include <linux/config.h>
#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] = 0;
return 0;
}
struct bus_type ccw_bus_type = {
.name = "ccw",
.match = &ccw_bus_match,
.uevent = &ccw_uevent,
};
static int io_subchannel_probe (struct device *);
static int io_subchannel_remove (struct device *);
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 device *);
struct css_driver io_subchannel_driver = {
.subchannel_type = SUBCHANNEL_TYPE_IO,
.drv = {
.name = "io_subchannel",
.bus = &css_bus_type,
.probe = &io_subchannel_probe,
.remove = &io_subchannel_remove,
.shutdown = &io_subchannel_shutdown,
},
.irq = io_subchannel_irq,
.notify = io_subchannel_notify,
.verify = io_subchannel_verify,
.termination = io_subchannel_ioterm,
};
struct workqueue_struct *ccw_device_work;
struct workqueue_struct *ccw_device_notify_work;
static wait_queue_head_t ccw_device_init_wq;
static 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);
device_unregister(&sch->dev);
/* 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 = {
.devno = devno,
.ssid = ssid,
.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);
}
device_unregister(&other_sch->dev);
}
}
/* 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);
device_unregister(&sch->dev);
/* 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 device *pdev)
{
struct subchannel *sch;
struct ccw_device *cdev;
int rc;
unsigned long flags;
sch = to_subchannel(pdev);
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 = kmalloc (sizeof(*cdev), GFP_KERNEL);
if (!cdev)
return -ENOMEM;
memset(cdev, 0, sizeof(struct ccw_device));
cdev->private = kmalloc(sizeof(struct ccw_device_private),
GFP_KERNEL | GFP_DMA);
if (!cdev->private) {
kfree(cdev);
return -ENOMEM;
}
memset(cdev->private, 0, sizeof(struct ccw_device_private));
atomic_set(&cdev->private->onoff, 0);
cdev->dev = (struct device) {
.parent = pdev,
.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, to_subchannel(pdev));
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 device *dev)
{
struct ccw_device *cdev;
unsigned long flags;
if (!dev->driver_data)
return 0;
cdev = dev->driver_data;
/* Set ccw device to not operational and drop reference. */
spin_lock_irqsave(cdev->ccwlock, flags);
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 device *dev)
{
struct subchannel *sch;
struct ccw_device *cdev;
int ret;
sch = to_subchannel(dev);
cdev = 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 = (struct device) {
.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 NULL;
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) : 0;
}
/************************** 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 = 0;
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 = 0;
return 0;
}
int
ccw_driver_register (struct ccw_driver *cdriver)
{
struct device_driver *drv = &cdriver->driver;
drv->bus = &ccw_bus_type;
drv->name = cdriver->name;
drv->probe = ccw_device_probe;
drv->remove = ccw_device_remove;
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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