linux/drivers/s390/cio/device.c

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/*
* drivers/s390/cio/device.c
* bus driver for ccw devices
*
* Copyright IBM Corp. 2002,2008
* 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 <linux/timer.h>
#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/param.h> /* HZ */
#include <asm/cmb.h>
#include <asm/isc.h>
#include "chp.h"
#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"
#include "io_sch.h"
#include "blacklist.h"
static struct timer_list recovery_timer;
static DEFINE_SPINLOCK(recovery_lock);
static int recovery_phase;
static const unsigned long recovery_delay[] = { 3, 30, 300 };
/******************* 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;
}
/* Store modalias string delimited by prefix/suffix string into buffer with
* specified size. Return length of resulting string (excluding trailing '\0')
* even if string doesn't fit buffer (snprintf semantics). */
static int snprint_alias(char *buf, size_t size,
struct ccw_device_id *id, const char *suffix)
{
int len;
len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
if (len > size)
return len;
buf += len;
size -= len;
if (id->dev_type != 0)
len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
id->dev_model, suffix);
else
len += snprintf(buf, size, "dtdm%s", suffix);
return len;
}
/* Set up environment variables for ccw device uevent. Return 0 on success,
* non-zero otherwise. */
static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_device_id *id = &(cdev->id);
int ret;
char modalias_buf[30];
/* CU_TYPE= */
ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
if (ret)
return ret;
/* CU_MODEL= */
ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
if (ret)
return ret;
/* The next two can be zero, that's ok for us */
/* DEV_TYPE= */
ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
if (ret)
return ret;
/* DEV_MODEL= */
ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
if (ret)
return ret;
/* MODALIAS= */
snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
return ret;
}
struct bus_type ccw_bus_type;
static void io_subchannel_irq(struct subchannel *);
static int io_subchannel_probe(struct subchannel *);
static int io_subchannel_remove(struct subchannel *);
static void io_subchannel_shutdown(struct subchannel *);
static int io_subchannel_sch_event(struct subchannel *, int);
static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
int);
static struct css_device_id io_subchannel_ids[] = {
{ .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
{ /* end of list */ },
};
MODULE_DEVICE_TABLE(css, io_subchannel_ids);
static struct css_driver io_subchannel_driver = {
.owner = THIS_MODULE,
.subchannel_type = io_subchannel_ids,
.name = "io_subchannel",
.irq = io_subchannel_irq,
.sch_event = io_subchannel_sch_event,
.chp_event = io_subchannel_chp_event,
.probe = io_subchannel_probe,
.remove = io_subchannel_remove,
.shutdown = io_subchannel_shutdown,
};
struct workqueue_struct *ccw_device_work;
wait_queue_head_t ccw_device_init_wq;
atomic_t ccw_device_init_count;
static void recovery_func(unsigned long data);
static int __init
init_ccw_bus_type (void)
{
int ret;
init_waitqueue_head(&ccw_device_init_wq);
atomic_set(&ccw_device_init_count, 0);
setup_timer(&recovery_timer, recovery_func, 0);
ccw_device_work = create_singlethread_workqueue("cio");
if (!ccw_device_work)
return -ENOMEM; /* FIXME: better errno ? */
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;
ret = css_driver_register(&io_subchannel_driver);
if (ret)
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 (slow_path_wq)
destroy_workqueue(slow_path_wq);
return ret;
}
static void __exit
cleanup_ccw_bus_type (void)
{
css_driver_unregister(&io_subchannel_driver);
bus_unregister(&ccw_bus_type);
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 chsc_ssd_info *ssd = &sch->ssd_info;
ssize_t ret = 0;
int chp;
int mask;
for (chp = 0; chp < 8; chp++) {
mask = 0x80 >> chp;
if (ssd->path_mask & mask)
ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
else
ret += sprintf(buf + ret, "00 ");
}
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 len;
len = snprint_alias(buf, PAGE_SIZE, id, "\n");
return len > PAGE_SIZE ? PAGE_SIZE : len;
}
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");
}
int ccw_device_is_orphan(struct ccw_device *cdev)
{
return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
}
static void ccw_device_unregister(struct ccw_device *cdev)
{
if (test_and_clear_bit(1, &cdev->private->registered))
device_del(&cdev->dev);
}
static void ccw_device_remove_orphan_cb(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
ccw_device_unregister(cdev);
put_device(&cdev->dev);
/* Release cdev reference for workqueue processing. */
put_device(&cdev->dev);
}
static void ccw_device_call_sch_unregister(struct work_struct *work);
static void
ccw_device_remove_disconnected(struct ccw_device *cdev)
{
unsigned long flags;
/*
* Forced offline in disconnected state means
* 'throw away device'.
*/
/* Get cdev reference for workqueue processing. */
if (!get_device(&cdev->dev))
return;
if (ccw_device_is_orphan(cdev)) {
/*
* Deregister ccw device.
* Unfortunately, we cannot do this directly from the
* attribute method.
*/
spin_lock_irqsave(cdev->ccwlock, flags);
cdev->private->state = DEV_STATE_NOT_OPER;
spin_unlock_irqrestore(cdev->ccwlock, flags);
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_remove_orphan_cb);
} else
/* Deregister subchannel, which will kill the ccw device. */
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_call_sch_unregister);
queue_work(slow_path_wq, &cdev->private->kick_work);
}
/**
* ccw_device_set_offline() - disable a ccw device for I/O
* @cdev: target ccw device
*
* This function calls the driver's set_offline() function for @cdev, if
* given, and then disables @cdev.
* Returns:
* %0 on success and a negative error value on failure.
* Context:
* enabled, ccw device lock not held
*/
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);
/* Give up reference from ccw_device_set_online(). */
put_device(&cdev->dev);
return ret;
}
spin_unlock_irq(cdev->ccwlock);
if (ret == 0) {
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
/* Give up reference from ccw_device_set_online(). */
put_device(&cdev->dev);
} else {
CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
cdev->online = 1;
}
return ret;
}
/**
* ccw_device_set_online() - enable a ccw device for I/O
* @cdev: target ccw device
*
* This function first enables @cdev and then calls the driver's set_online()
* function for @cdev, if given. If set_online() returns an error, @cdev is
* disabled again.
* Returns:
* %0 on success and a negative error value on failure.
* Context:
* enabled, ccw device lock not held
*/
int ccw_device_set_online(struct ccw_device *cdev)
{
int ret;
if (!cdev)
return -ENODEV;
if (cdev->online || !cdev->drv)
return -EINVAL;
/* Hold on to an extra reference while device is online. */
if (!get_device(&cdev->dev))
return -ENODEV;
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 {
CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
/* Give up online reference since onlining failed. */
put_device(&cdev->dev);
return ret;
}
if (cdev->private->state != DEV_STATE_ONLINE) {
/* Give up online reference since onlining failed. */
put_device(&cdev->dev);
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
CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
/* Give up online reference since onlining failed. */
put_device(&cdev->dev);
return (ret == 0) ? -ENODEV : ret;
}
static void online_store_handle_offline(struct ccw_device *cdev)
{
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);
}
static int online_store_recog_and_online(struct ccw_device *cdev)
{
int ret;
/* Do device recognition, if needed. */
if (cdev->id.cu_type == 0) {
ret = ccw_device_recognition(cdev);
if (ret) {
CIO_MSG_EVENT(0, "Couldn't start recognition "
"for device 0.%x.%04x (ret=%d)\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
return ret;
}
wait_event(cdev->private->wait_q,
cdev->private->flags.recog_done);
}
if (cdev->drv && cdev->drv->set_online)
ccw_device_set_online(cdev);
return 0;
}
static int online_store_handle_online(struct ccw_device *cdev, int force)
{
int ret;
ret = online_store_recog_and_online(cdev);
if (ret)
return ret;
if (force && cdev->private->state == DEV_STATE_BOXED) {
ret = ccw_device_stlck(cdev);
if (ret)
return ret;
if (cdev->id.cu_type == 0)
cdev->private->state = DEV_STATE_NOT_OPER;
online_store_recog_and_online(cdev);
}
return 0;
}
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 force, ret;
unsigned long i;
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;
ret = 0;
} else {
force = 0;
ret = strict_strtoul(buf, 16, &i);
}
if (ret)
goto out;
switch (i) {
case 0:
online_store_handle_offline(cdev);
ret = count;
break;
case 1:
ret = online_store_handle_online(cdev, force);
if (!ret)
ret = count;
break;
default:
ret = -EINVAL;
}
out:
if (cdev->drv)
module_put(cdev->drv->owner);
atomic_set(&cdev->private->onoff, 0);
return ret;
}
static ssize_t
available_show (struct device *dev, struct device_attribute *attr, char *buf)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct subchannel *sch;
if (ccw_device_is_orphan(cdev))
return sprintf(buf, "no device\n");
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);
static DEVICE_ATTR(availability, 0444, available_show, NULL);
static struct attribute *io_subchannel_attrs[] = {
&dev_attr_chpids.attr,
&dev_attr_pimpampom.attr,
NULL,
};
static struct attribute_group io_subchannel_attr_group = {
.attrs = io_subchannel_attrs,
};
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 struct attribute_group *ccwdev_attr_groups[] = {
&ccwdev_attr_group,
NULL,
};
/* this is a simple abstraction for device_register that sets the
* correct bus type and adds the bus specific files */
static 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);
return ret;
}
struct match_data {
struct ccw_dev_id dev_id;
struct ccw_device * sibling;
};
static int
match_devno(struct device * dev, void * data)
{
struct match_data * d = data;
struct ccw_device * cdev;
cdev = to_ccwdev(dev);
if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
!ccw_device_is_orphan(cdev) &&
ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
(cdev != d->sibling))
return 1;
return 0;
}
static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
struct ccw_device *sibling)
{
struct device *dev;
struct match_data data;
data.dev_id = *dev_id;
data.sibling = sibling;
dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
return dev ? to_ccwdev(dev) : NULL;
}
static int match_orphan(struct device *dev, void *data)
{
struct ccw_dev_id *dev_id;
struct ccw_device *cdev;
dev_id = data;
cdev = to_ccwdev(dev);
return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
}
static struct ccw_device *
get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
struct ccw_dev_id *dev_id)
{
struct device *dev;
dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
match_orphan);
return dev ? to_ccwdev(dev) : NULL;
}
static void
ccw_device_add_changed(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
if (device_add(&cdev->dev)) {
put_device(&cdev->dev);
return;
}
set_bit(1, &cdev->private->registered);
}
void ccw_device_do_unreg_rereg(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
struct subchannel *sch;
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
sch = to_subchannel(cdev->dev.parent);
ccw_device_unregister(cdev);
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_add_changed);
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);
/* Release reference of parent subchannel. */
put_device(cdev->dev.parent);
kfree(cdev->private);
kfree(cdev);
}
static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
{
struct ccw_device *cdev;
cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
if (cdev) {
cdev->private = kzalloc(sizeof(struct ccw_device_private),
GFP_KERNEL | GFP_DMA);
if (cdev->private)
return cdev;
}
kfree(cdev);
return ERR_PTR(-ENOMEM);
}
static int io_subchannel_initialize_dev(struct subchannel *sch,
struct ccw_device *cdev)
{
cdev->private->cdev = cdev;
atomic_set(&cdev->private->onoff, 0);
cdev->dev.parent = &sch->dev;
cdev->dev.release = ccw_device_release;
INIT_WORK(&cdev->private->kick_work, NULL);
cdev->dev.groups = ccwdev_attr_groups;
/* Do first half of device_register. */
device_initialize(&cdev->dev);
if (!get_device(&sch->dev)) {
/* Release reference from device_initialize(). */
put_device(&cdev->dev);
return -ENODEV;
}
return 0;
}
static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
{
struct ccw_device *cdev;
int ret;
cdev = io_subchannel_allocate_dev(sch);
if (!IS_ERR(cdev)) {
ret = io_subchannel_initialize_dev(sch, cdev);
if (ret) {
kfree(cdev);
cdev = ERR_PTR(ret);
}
}
return cdev;
}
static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
static void sch_attach_device(struct subchannel *sch,
struct ccw_device *cdev)
{
css_update_ssd_info(sch);
spin_lock_irq(sch->lock);
sch_set_cdev(sch, cdev);
cdev->private->schid = sch->schid;
cdev->ccwlock = sch->lock;
ccw_device_trigger_reprobe(cdev);
spin_unlock_irq(sch->lock);
}
static void sch_attach_disconnected_device(struct subchannel *sch,
struct ccw_device *cdev)
{
struct subchannel *other_sch;
int ret;
/* Get reference for new parent. */
if (!get_device(&sch->dev))
return;
other_sch = to_subchannel(cdev->dev.parent);
/* Note: device_move() changes cdev->dev.parent */
ret = device_move(&cdev->dev, &sch->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
"(ret=%d)!\n", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
/* Put reference for new parent. */
put_device(&sch->dev);
return;
}
sch_set_cdev(other_sch, NULL);
/* No need to keep a subchannel without ccw device around. */
css_sch_device_unregister(other_sch);
sch_attach_device(sch, cdev);
/* Put reference for old parent. */
put_device(&other_sch->dev);
}
static void sch_attach_orphaned_device(struct subchannel *sch,
struct ccw_device *cdev)
{
int ret;
struct subchannel *pseudo_sch;
/* Get reference for new parent. */
if (!get_device(&sch->dev))
return;
pseudo_sch = to_subchannel(cdev->dev.parent);
/*
* Try to move the ccw device to its new subchannel.
* Note: device_move() changes cdev->dev.parent
*/
ret = device_move(&cdev->dev, &sch->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
"failed (ret=%d)!\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
/* Put reference for new parent. */
put_device(&sch->dev);
return;
}
sch_attach_device(sch, cdev);
/* Put reference on pseudo subchannel. */
put_device(&pseudo_sch->dev);
}
static void sch_create_and_recog_new_device(struct subchannel *sch)
{
struct ccw_device *cdev;
/* Need to allocate a new ccw device. */
cdev = io_subchannel_create_ccwdev(sch);
if (IS_ERR(cdev)) {
/* OK, we did everything we could... */
css_sch_device_unregister(sch);
return;
}
spin_lock_irq(sch->lock);
sch_set_cdev(sch, cdev);
spin_unlock_irq(sch->lock);
/* Start recognition for the new ccw device. */
if (io_subchannel_recog(cdev, sch)) {
spin_lock_irq(sch->lock);
sch_set_cdev(sch, NULL);
spin_unlock_irq(sch->lock);
css_sch_device_unregister(sch);
/* Put reference from io_subchannel_create_ccwdev(). */
put_device(&sch->dev);
/* Give up initial reference. */
put_device(&cdev->dev);
}
}
void ccw_device_move_to_orphanage(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
struct ccw_device *replacing_cdev;
struct subchannel *sch;
int ret;
struct channel_subsystem *css;
struct ccw_dev_id dev_id;
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
sch = to_subchannel(cdev->dev.parent);
css = to_css(sch->dev.parent);
dev_id.devno = sch->schib.pmcw.dev;
dev_id.ssid = sch->schid.ssid;
/* Increase refcount for pseudo subchannel. */
get_device(&css->pseudo_subchannel->dev);
/*
* Move the orphaned ccw device to the orphanage so the replacing
* ccw device can take its place on the subchannel.
* Note: device_move() changes cdev->dev.parent
*/
ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
"(ret=%d)!\n", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
/* Decrease refcount for pseudo subchannel again. */
put_device(&css->pseudo_subchannel->dev);
return;
}
cdev->ccwlock = css->pseudo_subchannel->lock;
/*
* Search for the replacing ccw device
* - among the disconnected devices
* - in the orphanage
*/
replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
if (replacing_cdev) {
sch_attach_disconnected_device(sch, replacing_cdev);
/* Release reference from get_disc_ccwdev_by_dev_id() */
put_device(&replacing_cdev->dev);
/* Release reference of subchannel from old cdev. */
put_device(&sch->dev);
return;
}
replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
if (replacing_cdev) {
sch_attach_orphaned_device(sch, replacing_cdev);
/* Release reference from get_orphaned_ccwdev_by_dev_id() */
put_device(&replacing_cdev->dev);
/* Release reference of subchannel from old cdev. */
put_device(&sch->dev);
return;
}
sch_create_and_recog_new_device(sch);
/* Release reference of subchannel from old cdev. */
put_device(&sch->dev);
}
/*
* Register recognized device.
*/
static void
io_subchannel_register(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
struct subchannel *sch;
int ret;
unsigned long flags;
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
sch = to_subchannel(cdev->dev.parent);
/*
* Check if subchannel is still registered. It may have become
* unregistered if a machine check hit us after finishing
* device recognition but before the register work could be
* queued.
*/
if (!device_is_registered(&sch->dev))
goto out_err;
css_update_ssd_info(sch);
/*
* io_subchannel_register() will also be called after device
* recognition has been done for a boxed device (which will already
* be registered). We need to reprobe since we may now have sense id
* information.
*/
if (device_is_registered(&cdev->dev)) {
if (!cdev->drv) {
ret = device_reprobe(&cdev->dev);
if (ret)
/* We can't do much here. */
CIO_MSG_EVENT(0, "device_reprobe() returned"
" %d for 0.%x.%04x\n", ret,
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
}
goto out;
}
/*
* Now we know this subchannel will stay, we can throw
* our delayed uevent.
*/
sch->dev.uevent_suppress = 0;
kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
/* make it known to the system */
ret = ccw_device_register(cdev);
if (ret) {
CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
spin_lock_irqsave(sch->lock, flags);
sch_set_cdev(sch, NULL);
spin_unlock_irqrestore(sch->lock, flags);
/* Release initial device reference. */
put_device(&cdev->dev);
goto out_err;
}
out:
cdev->private->flags.recog_done = 1;
wake_up(&cdev->private->wait_q);
out_err:
/* Release reference for workqueue processing. */
put_device(&cdev->dev);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
}
static void ccw_device_call_sch_unregister(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
struct subchannel *sch;
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
/* Get subchannel reference for local processing. */
if (!get_device(cdev->dev.parent))
return;
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
sch->config.intparm = 0;
cio_commit_config(sch);
/* Release cdev reference for workqueue processing.*/
put_device(&cdev->dev);
/* Release subchannel reference for local processing. */
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);
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);
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_set_cdev(sch, cdev);
cdev->ccwlock = sch->lock;
/* Init private data. */
priv = cdev->private;
priv->dev_id.devno = sch->schib.pmcw.dev;
priv->dev_id.ssid = sch->schid.ssid;
priv->schid = sch->schid;
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. */
if (cio_is_console(sch->schid))
cdev->dev.init_name = cio_get_console_cdev_name(sch);
else
dev_set_name(&cdev->dev, "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 void ccw_device_move_to_sch(struct work_struct *work)
{
struct ccw_device_private *priv;
int rc;
struct subchannel *sch;
struct ccw_device *cdev;
struct subchannel *former_parent;
priv = container_of(work, struct ccw_device_private, kick_work);
sch = priv->sch;
cdev = priv->cdev;
former_parent = to_subchannel(cdev->dev.parent);
/* Get reference for new parent. */
if (!get_device(&sch->dev))
return;
mutex_lock(&sch->reg_mutex);
/*
* Try to move the ccw device to its new subchannel.
* Note: device_move() changes cdev->dev.parent
*/
rc = device_move(&cdev->dev, &sch->dev);
mutex_unlock(&sch->reg_mutex);
if (rc) {
CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
"0.%x.%04x failed (ret=%d)!\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, sch->schid.ssid,
sch->schid.sch_no, rc);
css_sch_device_unregister(sch);
/* Put reference for new parent again. */
put_device(&sch->dev);
goto out;
}
if (!sch_is_pseudo_sch(former_parent)) {
spin_lock_irq(former_parent->lock);
sch_set_cdev(former_parent, NULL);
spin_unlock_irq(former_parent->lock);
css_sch_device_unregister(former_parent);
/* Reset intparm to zeroes. */
former_parent->config.intparm = 0;
cio_commit_config(former_parent);
}
sch_attach_device(sch, cdev);
out:
/* Put reference for old parent. */
put_device(&former_parent->dev);
put_device(&cdev->dev);
}
static void io_subchannel_irq(struct subchannel *sch)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
CIO_TRACE_EVENT(3, "IRQ");
CIO_TRACE_EVENT(3, dev_name(&sch->dev));
if (cdev)
dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
}
void io_subchannel_init_config(struct subchannel *sch)
{
memset(&sch->config, 0, sizeof(sch->config));
sch->config.csense = 1;
if ((sch->lpm & (sch->lpm - 1)) != 0)
sch->config.mp = 1;
}
static void io_subchannel_init_fields(struct subchannel *sch)
{
if (cio_is_console(sch->schid))
sch->opm = 0xff;
else
sch->opm = chp_get_sch_opm(sch);
sch->lpm = sch->schib.pmcw.pam & sch->opm;
sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
" - PIM = %02X, PAM = %02X, POM = %02X\n",
sch->schib.pmcw.dev, sch->schid.ssid,
sch->schid.sch_no, sch->schib.pmcw.pim,
sch->schib.pmcw.pam, sch->schib.pmcw.pom);
io_subchannel_init_config(sch);
}
static void io_subchannel_do_unreg(struct work_struct *work)
{
struct subchannel *sch;
sch = container_of(work, struct subchannel, work);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
sch->config.intparm = 0;
cio_commit_config(sch);
put_device(&sch->dev);
}
/* Schedule unregister if we have no cdev. */
static void io_subchannel_schedule_removal(struct subchannel *sch)
{
get_device(&sch->dev);
INIT_WORK(&sch->work, io_subchannel_do_unreg);
queue_work(slow_path_wq, &sch->work);
}
/*
* Note: We always return 0 so that we bind to the device even on error.
* This is needed so that our remove function is called on unregister.
*/
static int io_subchannel_probe(struct subchannel *sch)
{
struct ccw_device *cdev;
int rc;
unsigned long flags;
struct ccw_dev_id dev_id;
cdev = sch_get_cdev(sch);
if (cdev) {
rc = sysfs_create_group(&sch->dev.kobj,
&io_subchannel_attr_group);
if (rc)
CIO_MSG_EVENT(0, "Failed to create io subchannel "
"attributes for subchannel "
"0.%x.%04x (rc=%d)\n",
sch->schid.ssid, sch->schid.sch_no, rc);
/*
* This subchannel already has an associated ccw_device.
* Throw the delayed uevent for the subchannel, register
* the ccw_device and exit. This happens for all early
* devices, e.g. the console.
*/
sch->dev.uevent_suppress = 0;
kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
cdev->dev.groups = ccwdev_attr_groups;
device_initialize(&cdev->dev);
ccw_device_register(cdev);
/*
* Check if the device is already online. If it is
* the reference count needs to be corrected since we
* didn't obtain a reference in ccw_device_set_online.
*/
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;
}
io_subchannel_init_fields(sch);
rc = sysfs_create_group(&sch->dev.kobj,
&io_subchannel_attr_group);
if (rc)
goto out_schedule;
/* Allocate I/O subchannel private data. */
sch->private = kzalloc(sizeof(struct io_subchannel_private),
GFP_KERNEL | GFP_DMA);
if (!sch->private)
goto out_err;
/*
* First check if a fitting device may be found amongst the
* disconnected devices or in the orphanage.
*/
dev_id.devno = sch->schib.pmcw.dev;
dev_id.ssid = sch->schid.ssid;
cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
if (!cdev)
cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
&dev_id);
if (cdev) {
/*
* Schedule moving the device until when we have a registered
* subchannel to move to and succeed the probe. We can
* unregister later again, when the probe is through.
*/
cdev->private->sch = sch;
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_move_to_sch);
queue_work(slow_path_wq, &cdev->private->kick_work);
return 0;
}
cdev = io_subchannel_create_ccwdev(sch);
if (IS_ERR(cdev))
goto out_err;
rc = io_subchannel_recog(cdev, sch);
if (rc) {
spin_lock_irqsave(sch->lock, flags);
io_subchannel_recog_done(cdev);
spin_unlock_irqrestore(sch->lock, flags);
}
return 0;
out_err:
kfree(sch->private);
sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
out_schedule:
io_subchannel_schedule_removal(sch);
return 0;
}
static int
io_subchannel_remove (struct subchannel *sch)
{
struct ccw_device *cdev;
unsigned long flags;
cdev = sch_get_cdev(sch);
if (!cdev)
return 0;
/* Set ccw device to not operational and drop reference. */
spin_lock_irqsave(cdev->ccwlock, flags);
sch_set_cdev(sch, NULL);
cdev->private->state = DEV_STATE_NOT_OPER;
spin_unlock_irqrestore(cdev->ccwlock, flags);
ccw_device_unregister(cdev);
put_device(&cdev->dev);
kfree(sch->private);
sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
return 0;
}
static int io_subchannel_notify(struct subchannel *sch, int event)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
if (!cdev)
return 0;
return ccw_device_notify(cdev, event);
}
static void io_subchannel_verify(struct subchannel *sch)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
if (cdev)
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
}
static int check_for_io_on_path(struct subchannel *sch, int mask)
{
if (cio_update_schib(sch))
return 0;
if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
return 1;
return 0;
}
static void terminate_internal_io(struct subchannel *sch,
struct ccw_device *cdev)
{
if (cio_clear(sch)) {
/* Recheck device in case clear failed. */
sch->lpm = 0;
if (cdev->online)
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
else
css_schedule_eval(sch->schid);
return;
}
cdev->private->state = DEV_STATE_CLEAR_VERIFY;
/* Request retry of internal operation. */
cdev->private->flags.intretry = 1;
/* Call handler. */
if (cdev->handler)
cdev->handler(cdev, cdev->private->intparm,
ERR_PTR(-EIO));
}
static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
if (!cdev)
return;
if (check_for_io_on_path(sch, mask)) {
if (cdev->private->state == DEV_STATE_ONLINE)
ccw_device_kill_io(cdev);
else {
terminate_internal_io(sch, cdev);
/* Re-start path verification. */
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
}
} else
/* trigger path verification. */
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
}
static int io_subchannel_chp_event(struct subchannel *sch,
struct chp_link *link, int event)
{
int mask;
mask = chp_ssd_get_mask(&sch->ssd_info, link);
if (!mask)
return 0;
switch (event) {
case CHP_VARY_OFF:
sch->opm &= ~mask;
sch->lpm &= ~mask;
io_subchannel_terminate_path(sch, mask);
break;
case CHP_VARY_ON:
sch->opm |= mask;
sch->lpm |= mask;
io_subchannel_verify(sch);
break;
case CHP_OFFLINE:
if (cio_update_schib(sch))
return -ENODEV;
io_subchannel_terminate_path(sch, mask);
break;
case CHP_ONLINE:
if (cio_update_schib(sch))
return -ENODEV;
sch->lpm |= mask & sch->opm;
io_subchannel_verify(sch);
break;
}
return 0;
}
static void
io_subchannel_shutdown(struct subchannel *sch)
{
struct ccw_device *cdev;
int ret;
cdev = sch_get_cdev(sch);
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);
}
static int io_subchannel_get_status(struct subchannel *sch)
{
struct schib schib;
if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
return CIO_GONE;
if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
return CIO_REVALIDATE;
if (!sch->lpm)
return CIO_NO_PATH;
return CIO_OPER;
}
static int device_is_disconnected(struct ccw_device *cdev)
{
if (!cdev)
return 0;
return (cdev->private->state == DEV_STATE_DISCONNECTED ||
cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
}
static int recovery_check(struct device *dev, void *data)
{
struct ccw_device *cdev = to_ccwdev(dev);
int *redo = data;
spin_lock_irq(cdev->ccwlock);
switch (cdev->private->state) {
case DEV_STATE_DISCONNECTED:
CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
*redo = 1;
break;
case DEV_STATE_DISCONNECTED_SENSE_ID:
*redo = 1;
break;
}
spin_unlock_irq(cdev->ccwlock);
return 0;
}
static void recovery_work_func(struct work_struct *unused)
{
int redo = 0;
bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
if (redo) {
spin_lock_irq(&recovery_lock);
if (!timer_pending(&recovery_timer)) {
if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
recovery_phase++;
mod_timer(&recovery_timer, jiffies +
recovery_delay[recovery_phase] * HZ);
}
spin_unlock_irq(&recovery_lock);
} else
CIO_MSG_EVENT(4, "recovery: end\n");
}
static DECLARE_WORK(recovery_work, recovery_work_func);
static void recovery_func(unsigned long data)
{
/*
* We can't do our recovery in softirq context and it's not
* performance critical, so we schedule it.
*/
schedule_work(&recovery_work);
}
static void ccw_device_schedule_recovery(void)
{
unsigned long flags;
CIO_MSG_EVENT(4, "recovery: schedule\n");
spin_lock_irqsave(&recovery_lock, flags);
if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
recovery_phase = 0;
mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
}
spin_unlock_irqrestore(&recovery_lock, flags);
}
static int purge_fn(struct device *dev, void *data)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_device_private *priv = cdev->private;
int unreg;
spin_lock_irq(cdev->ccwlock);
unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
(priv->state == DEV_STATE_OFFLINE);
spin_unlock_irq(cdev->ccwlock);
if (!unreg)
goto out;
if (!get_device(&cdev->dev))
goto out;
CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
priv->dev_id.devno);
PREPARE_WORK(&cdev->private->kick_work, ccw_device_call_sch_unregister);
queue_work(slow_path_wq, &cdev->private->kick_work);
out:
/* Abort loop in case of pending signal. */
if (signal_pending(current))
return -EINTR;
return 0;
}
/**
* ccw_purge_blacklisted - purge unused, blacklisted devices
*
* Unregister all ccw devices that are offline and on the blacklist.
*/
int ccw_purge_blacklisted(void)
{
CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
return 0;
}
static void device_set_disconnected(struct ccw_device *cdev)
{
if (!cdev)
return;
ccw_device_set_timeout(cdev, 0);
cdev->private->flags.fake_irb = 0;
cdev->private->state = DEV_STATE_DISCONNECTED;
if (cdev->online)
ccw_device_schedule_recovery();
}
void ccw_device_set_notoper(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
CIO_TRACE_EVENT(2, "notoper");
CIO_TRACE_EVENT(2, dev_name(&sch->dev));
ccw_device_set_timeout(cdev, 0);
cio_disable_subchannel(sch);
cdev->private->state = DEV_STATE_NOT_OPER;
}
static int io_subchannel_sch_event(struct subchannel *sch, int slow)
{
int event, ret, disc;
unsigned long flags;
enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
struct ccw_device *cdev;
spin_lock_irqsave(sch->lock, flags);
cdev = sch_get_cdev(sch);
disc = device_is_disconnected(cdev);
if (disc && slow) {
/* Disconnected devices are evaluated directly only.*/
spin_unlock_irqrestore(sch->lock, flags);
return 0;
}
/* No interrupt after machine check - kill pending timers. */
if (cdev)
ccw_device_set_timeout(cdev, 0);
if (!disc && !slow) {
/* Non-disconnected devices are evaluated on the slow path. */
spin_unlock_irqrestore(sch->lock, flags);
return -EAGAIN;
}
event = io_subchannel_get_status(sch);
CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
sch->schid.ssid, sch->schid.sch_no, event,
disc ? "disconnected" : "normal",
slow ? "slow" : "fast");
/* Analyze subchannel status. */
action = NONE;
switch (event) {
case CIO_NO_PATH:
if (disc) {
/* Check if paths have become available. */
action = REPROBE;
break;
}
/* fall through */
case CIO_GONE:
/* Ask driver what to do with device. */
if (io_subchannel_notify(sch, event))
action = DISC;
else
action = UNREGISTER;
break;
case CIO_REVALIDATE:
/* Device will be removed, so no notify necessary. */
if (disc)
/* Reprobe because immediate unregister might block. */
action = REPROBE;
else
action = UNREGISTER_PROBE;
break;
case CIO_OPER:
if (disc)
/* Get device operational again. */
action = REPROBE;
break;
}
/* Perform action. */
ret = 0;
switch (action) {
case UNREGISTER:
case UNREGISTER_PROBE:
ccw_device_set_notoper(cdev);
/* Unregister device (will use subchannel lock). */
spin_unlock_irqrestore(sch->lock, flags);
css_sch_device_unregister(sch);
spin_lock_irqsave(sch->lock, flags);
/* Reset intparm to zeroes. */
sch->config.intparm = 0;
cio_commit_config(sch);
break;
case REPROBE:
ccw_device_trigger_reprobe(cdev);
break;
case DISC:
device_set_disconnected(cdev);
break;
default:
break;
}
spin_unlock_irqrestore(sch->lock, flags);
/* Probe if necessary. */
if (action == UNREGISTER_PROBE)
ret = css_probe_device(sch->schid);
return ret;
}
#ifdef CONFIG_CCW_CONSOLE
static struct ccw_device console_cdev;
static char console_cdev_name[10] = "0.x.xxxx";
static struct ccw_device_private console_private;
static int console_cdev_in_use;
static DEFINE_SPINLOCK(ccw_console_lock);
spinlock_t * cio_get_console_lock(void)
{
return &ccw_console_lock;
}
static int ccw_device_console_enable(struct ccw_device *cdev,
struct subchannel *sch)
{
int rc;
/* Attach subchannel private data. */
sch->private = cio_get_console_priv();
memset(sch->private, 0, sizeof(struct io_subchannel_private));
io_subchannel_init_fields(sch);
sch->driver = &io_subchannel_driver;
/* 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;
console_private.cdev = &console_cdev;
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;
}
const char *cio_get_console_cdev_name(struct subchannel *sch)
{
snprintf(console_cdev_name, 10, "0.%x.%04x",
sch->schid.ssid, sch->schib.pmcw.dev);
return (const char *)console_cdev_name;
}
#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 = id;
return (strcmp(bus_id, dev_name(dev)) == 0);
}
/**
* get_ccwdev_by_busid() - obtain device from a bus id
* @cdrv: driver the device is owned by
* @bus_id: bus id of the device to be searched
*
* This function searches all devices owned by @cdrv for a device with a bus
* id matching @bus_id.
* Returns:
* If a match is found, its reference count of the found device is increased
* and it is returned; else %NULL is returned.
*/
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;
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
CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
/* Give up reference obtained in ccw_device_set_online(). */
put_device(&cdev->dev);
}
ccw_device_set_timeout(cdev, 0);
cdev->drv = NULL;
return 0;
}
static void ccw_device_shutdown(struct device *dev)
{
struct ccw_device *cdev;
cdev = to_ccwdev(dev);
if (cdev->drv && cdev->drv->shutdown)
cdev->drv->shutdown(cdev);
disable_cmf(cdev);
}
struct bus_type ccw_bus_type = {
.name = "ccw",
.match = ccw_bus_match,
.uevent = ccw_uevent,
.probe = ccw_device_probe,
.remove = ccw_device_remove,
.shutdown = ccw_device_shutdown,
};
/**
* ccw_driver_register() - register a ccw driver
* @cdriver: driver to be registered
*
* This function is mainly a wrapper around driver_register().
* Returns:
* %0 on success and a negative error value on failure.
*/
int ccw_driver_register(struct ccw_driver *cdriver)
{
struct device_driver *drv = &cdriver->driver;
drv->bus = &ccw_bus_type;
drv->name = cdriver->name;
drv->owner = cdriver->owner;
return driver_register(drv);
}
/**
* ccw_driver_unregister() - deregister a ccw driver
* @cdriver: driver to be deregistered
*
* This function is mainly a wrapper around driver_unregister().
*/
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_GPL(ccw_device_get_subchannel_id);