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linux/drivers/s390/cio/device.c
Sebastian Ott 55fb734757 s390/cio: recover from bad paths 
In some situations we don't receive notification from firmware that
a previously unusable channelpath is usable again.

Schedule recovery for devices that return from path verification
without using all potentially usable paths. The recovery thread will
periodically trigger a path verification on the affected devices.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Suggested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-09-19 08:36:19 +02:00

2124 lines
53 KiB
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/*
* 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)
*
* License: GPL
*/
#define KMSG_COMPONENT "cio"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/export.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/delay.h>
#include <linux/timer.h>
#include <linux/kernel_stat.h>
#include <linux/sched/signal.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"
#include "chsc.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 };
static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
static struct bus_type ccw_bus_type;
/******************* 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;
}
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 void recovery_func(unsigned long data);
static struct css_device_id io_subchannel_ids[] = {
{ .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
{ /* end of list */ },
};
static int io_subchannel_prepare(struct subchannel *sch)
{
struct ccw_device *cdev;
/*
* Don't allow suspend while a ccw device registration
* is still outstanding.
*/
cdev = sch_get_cdev(sch);
if (cdev && !device_is_registered(&cdev->dev))
return -EAGAIN;
return 0;
}
static int io_subchannel_settle(void)
{
int ret;
ret = wait_event_interruptible(ccw_device_init_wq,
atomic_read(&ccw_device_init_count) == 0);
if (ret)
return -EINTR;
flush_workqueue(cio_work_q);
return 0;
}
static struct css_driver io_subchannel_driver = {
.drv = {
.owner = THIS_MODULE,
.name = "io_subchannel",
},
.subchannel_type = io_subchannel_ids,
.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,
.prepare = io_subchannel_prepare,
.settle = io_subchannel_settle,
};
int __init io_subchannel_init(void)
{
int ret;
setup_timer(&recovery_timer, recovery_func, 0);
ret = bus_register(&ccw_bus_type);
if (ret)
return ret;
ret = css_driver_register(&io_subchannel_driver);
if (ret)
bus_unregister(&ccw_bus_type);
return ret;
}
/************************ device handling **************************/
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 (device_is_registered(&cdev->dev)) {
/* Undo device_add(). */
device_del(&cdev->dev);
}
if (cdev->private->flags.initialized) {
cdev->private->flags.initialized = 0;
/* Release reference from device_initialize(). */
put_device(&cdev->dev);
}
}
static void io_subchannel_quiesce(struct subchannel *);
/**
* 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)
{
struct subchannel *sch;
int ret, state;
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;
}
spin_lock_irq(cdev->ccwlock);
sch = to_subchannel(cdev->dev.parent);
cdev->online = 0;
/* Wait until a final state or DISCONNECTED is reached */
while (!dev_fsm_final_state(cdev) &&
cdev->private->state != DEV_STATE_DISCONNECTED) {
spin_unlock_irq(cdev->ccwlock);
wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
cdev->private->state == DEV_STATE_DISCONNECTED));
spin_lock_irq(cdev->ccwlock);
}
do {
ret = ccw_device_offline(cdev);
if (!ret)
break;
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);
if (ret != -EBUSY)
goto error;
state = cdev->private->state;
spin_unlock_irq(cdev->ccwlock);
io_subchannel_quiesce(sch);
spin_lock_irq(cdev->ccwlock);
cdev->private->state = state;
} while (ret == -EBUSY);
spin_unlock_irq(cdev->ccwlock);
wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
cdev->private->state == DEV_STATE_DISCONNECTED));
/* Inform the user if set offline failed. */
if (cdev->private->state == DEV_STATE_BOXED) {
pr_warn("%s: The device entered boxed state while being set offline\n",
dev_name(&cdev->dev));
} else if (cdev->private->state == DEV_STATE_NOT_OPER) {
pr_warn("%s: The device stopped operating while being set offline\n",
dev_name(&cdev->dev));
}
/* Give up reference from ccw_device_set_online(). */
put_device(&cdev->dev);
return 0;
error:
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 -ENODEV;
}
/**
* 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;
int ret2;
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;
}
spin_lock_irq(cdev->ccwlock);
/* Check if online processing was successful */
if ((cdev->private->state != DEV_STATE_ONLINE) &&
(cdev->private->state != DEV_STATE_W4SENSE)) {
spin_unlock_irq(cdev->ccwlock);
/* Inform the user that set online failed. */
if (cdev->private->state == DEV_STATE_BOXED) {
pr_warn("%s: Setting the device online failed because it is boxed\n",
dev_name(&cdev->dev));
} else if (cdev->private->state == DEV_STATE_NOT_OPER) {
pr_warn("%s: Setting the device online failed because it is not operational\n",
dev_name(&cdev->dev));
}
/* Give up online reference since onlining failed. */
put_device(&cdev->dev);
return -ENODEV;
}
spin_unlock_irq(cdev->ccwlock);
if (cdev->drv->set_online)
ret = cdev->drv->set_online(cdev);
if (ret)
goto rollback;
spin_lock_irq(cdev->ccwlock);
cdev->online = 1;
spin_unlock_irq(cdev->ccwlock);
return 0;
rollback:
spin_lock_irq(cdev->ccwlock);
/* Wait until a final state or DISCONNECTED is reached */
while (!dev_fsm_final_state(cdev) &&
cdev->private->state != DEV_STATE_DISCONNECTED) {
spin_unlock_irq(cdev->ccwlock);
wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
cdev->private->state == DEV_STATE_DISCONNECTED));
spin_lock_irq(cdev->ccwlock);
}
ret2 = ccw_device_offline(cdev);
if (ret2)
goto error;
spin_unlock_irq(cdev->ccwlock);
wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
cdev->private->state == DEV_STATE_DISCONNECTED));
/* Give up online reference since onlining failed. */
put_device(&cdev->dev);
return ret;
error:
CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
"device 0.%x.%04x\n",
ret2, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
cdev->private->state = DEV_STATE_OFFLINE;
spin_unlock_irq(cdev->ccwlock);
/* Give up online reference since onlining failed. */
put_device(&cdev->dev);
return ret;
}
static int online_store_handle_offline(struct ccw_device *cdev)
{
if (cdev->private->state == DEV_STATE_DISCONNECTED) {
spin_lock_irq(cdev->ccwlock);
ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
spin_unlock_irq(cdev->ccwlock);
return 0;
}
if (cdev->drv && cdev->drv->set_offline)
return ccw_device_set_offline(cdev);
return -EINVAL;
}
static int online_store_recog_and_online(struct ccw_device *cdev)
{
/* Do device recognition, if needed. */
if (cdev->private->state == DEV_STATE_BOXED) {
spin_lock_irq(cdev->ccwlock);
ccw_device_recognition(cdev);
spin_unlock_irq(cdev->ccwlock);
wait_event(cdev->private->wait_q,
cdev->private->flags.recog_done);
if (cdev->private->state != DEV_STATE_OFFLINE)
/* recognition failed */
return -EAGAIN;
}
if (cdev->drv && cdev->drv->set_online)
return ccw_device_set_online(cdev);
return -EINVAL;
}
static int online_store_handle_online(struct ccw_device *cdev, int force)
{
int ret;
ret = online_store_recog_and_online(cdev);
if (ret && !force)
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;
ret = online_store_recog_and_online(cdev);
if (ret)
return ret;
}
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;
/* Prevent conflict between multiple on-/offline processing requests. */
if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
return -EAGAIN;
/* Prevent conflict between internal I/Os and on-/offline processing. */
if (!dev_fsm_final_state(cdev) &&
cdev->private->state != DEV_STATE_DISCONNECTED) {
ret = -EAGAIN;
goto out;
}
/* Prevent conflict between pending work and on-/offline processing.*/
if (work_pending(&cdev->private->todo_work)) {
ret = -EAGAIN;
goto out;
}
if (!strncmp(buf, "force\n", count)) {
force = 1;
i = 1;
ret = 0;
} else {
force = 0;
ret = kstrtoul(buf, 16, &i);
}
if (ret)
goto out;
device_lock(dev);
switch (i) {
case 0:
ret = online_store_handle_offline(cdev);
break;
case 1:
ret = online_store_handle_online(cdev, force);
break;
default:
ret = -EINVAL;
}
device_unlock(dev);
out:
atomic_set(&cdev->private->onoff, 0);
return (ret < 0) ? ret : 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;
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 ssize_t
initiate_logging(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct subchannel *sch = to_subchannel(dev);
int rc;
rc = chsc_siosl(sch->schid);
if (rc < 0) {
pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
sch->schid.ssid, sch->schid.sch_no, rc);
return rc;
}
pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
sch->schid.ssid, sch->schid.sch_no);
return count;
}
static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct subchannel *sch = to_subchannel(dev);
return sprintf(buf, "%02x\n", sch->vpm);
}
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 DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
static DEVICE_ATTR(vpm, 0444, vpm_show, NULL);
static struct attribute *io_subchannel_attrs[] = {
&dev_attr_logging.attr,
&dev_attr_vpm.attr,
NULL,
};
static const 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 const struct attribute_group ccwdev_attr_group = {
.attrs = ccwdev_attrs,
};
static const struct attribute_group *ccwdev_attr_groups[] = {
&ccwdev_attr_group,
NULL,
};
static int ccw_device_add(struct ccw_device *cdev)
{
struct device *dev = &cdev->dev;
dev->bus = &ccw_bus_type;
return device_add(dev);
}
static int match_dev_id(struct device *dev, void *data)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_dev_id *dev_id = data;
return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
}
/**
* get_ccwdev_by_dev_id() - obtain device from a ccw device id
* @dev_id: id of the device to be searched
*
* This function searches all devices attached to the ccw bus for a device
* matching @dev_id.
* Returns:
* If a device is found its reference count is increased and returned;
* else %NULL is returned.
*/
struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
{
struct device *dev;
dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
return dev ? to_ccwdev(dev) : NULL;
}
EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
{
int ret;
if (device_is_registered(&cdev->dev)) {
device_release_driver(&cdev->dev);
ret = device_attach(&cdev->dev);
WARN_ON(ret == -ENODEV);
}
}
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 void ccw_device_todo(struct work_struct *work);
static int io_subchannel_initialize_dev(struct subchannel *sch,
struct ccw_device *cdev)
{
struct ccw_device_private *priv = cdev->private;
int ret;
priv->cdev = cdev;
priv->int_class = IRQIO_CIO;
priv->state = DEV_STATE_NOT_OPER;
priv->dev_id.devno = sch->schib.pmcw.dev;
priv->dev_id.ssid = sch->schid.ssid;
INIT_WORK(&priv->todo_work, ccw_device_todo);
INIT_LIST_HEAD(&priv->cmb_list);
init_waitqueue_head(&priv->wait_q);
init_timer(&priv->timer);
atomic_set(&priv->onoff, 0);
cdev->ccwlock = sch->lock;
cdev->dev.parent = &sch->dev;
cdev->dev.release = ccw_device_release;
cdev->dev.groups = ccwdev_attr_groups;
/* Do first half of device_register. */
device_initialize(&cdev->dev);
ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
if (ret)
goto out_put;
if (!get_device(&sch->dev)) {
ret = -ENODEV;
goto out_put;
}
priv->flags.initialized = 1;
spin_lock_irq(sch->lock);
sch_set_cdev(sch, cdev);
spin_unlock_irq(sch->lock);
return 0;
out_put:
/* Release reference from device_initialize(). */
put_device(&cdev->dev);
return ret;
}
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)
cdev = ERR_PTR(ret);
}
return cdev;
}
static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
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;
}
/* Start recognition for the new ccw device. */
io_subchannel_recog(cdev, sch);
}
/*
* Register recognized device.
*/
static void io_subchannel_register(struct ccw_device *cdev)
{
struct subchannel *sch;
int ret, adjust_init_count = 1;
unsigned long flags;
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);
}
adjust_init_count = 0;
goto out;
}
/*
* Now we know this subchannel will stay, we can throw
* our delayed uevent.
*/
dev_set_uevent_suppress(&sch->dev, 0);
kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
/* make it known to the system */
ret = ccw_device_add(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:
if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
}
static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
{
struct subchannel *sch;
/* Get subchannel reference for local processing. */
if (!get_device(cdev->dev.parent))
return;
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* 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)
{
if (css_init_done == 0) {
cdev->private->flags.recog_done = 1;
return;
}
switch (cdev->private->state) {
case DEV_STATE_BOXED:
/* Device did not respond in time. */
case DEV_STATE_NOT_OPER:
cdev->private->flags.recog_done = 1;
/* Remove device found not operational. */
ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
break;
case DEV_STATE_OFFLINE:
/*
* We can't register the device in interrupt context so
* we schedule a work item.
*/
ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
break;
}
}
static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
{
/* Increase counter of devices currently in recognition. */
atomic_inc(&ccw_device_init_count);
/* Start async. device sensing. */
spin_lock_irq(sch->lock);
ccw_device_recognition(cdev);
spin_unlock_irq(sch->lock);
}
static int ccw_device_move_to_sch(struct ccw_device *cdev,
struct subchannel *sch)
{
struct subchannel *old_sch;
int rc, old_enabled = 0;
old_sch = to_subchannel(cdev->dev.parent);
/* Obtain child reference for new parent. */
if (!get_device(&sch->dev))
return -ENODEV;
if (!sch_is_pseudo_sch(old_sch)) {
spin_lock_irq(old_sch->lock);
old_enabled = old_sch->schib.pmcw.ena;
rc = 0;
if (old_enabled)
rc = cio_disable_subchannel(old_sch);
spin_unlock_irq(old_sch->lock);
if (rc == -EBUSY) {
/* Release child reference for new parent. */
put_device(&sch->dev);
return rc;
}
}
mutex_lock(&sch->reg_mutex);
rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
mutex_unlock(&sch->reg_mutex);
if (rc) {
CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, sch->schid.ssid,
sch->schib.pmcw.dev, rc);
if (old_enabled) {
/* Try to reenable the old subchannel. */
spin_lock_irq(old_sch->lock);
cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
spin_unlock_irq(old_sch->lock);
}
/* Release child reference for new parent. */
put_device(&sch->dev);
return rc;
}
/* Clean up old subchannel. */
if (!sch_is_pseudo_sch(old_sch)) {
spin_lock_irq(old_sch->lock);
sch_set_cdev(old_sch, NULL);
spin_unlock_irq(old_sch->lock);
css_schedule_eval(old_sch->schid);
}
/* Release child reference for old parent. */
put_device(&old_sch->dev);
/* Initialize new subchannel. */
spin_lock_irq(sch->lock);
cdev->ccwlock = sch->lock;
if (!sch_is_pseudo_sch(sch))
sch_set_cdev(sch, cdev);
spin_unlock_irq(sch->lock);
if (!sch_is_pseudo_sch(sch))
css_update_ssd_info(sch);
return 0;
}
static int ccw_device_move_to_orph(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct channel_subsystem *css = to_css(sch->dev.parent);
return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
}
static void io_subchannel_irq(struct subchannel *sch)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
CIO_TRACE_EVENT(6, "IRQ");
CIO_TRACE_EVENT(6, dev_name(&sch->dev));
if (cdev)
dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
else
inc_irq_stat(IRQIO_CIO);
}
void io_subchannel_init_config(struct subchannel *sch)
{
memset(&sch->config, 0, sizeof(sch->config));
sch->config.csense = 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);
}
/*
* 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 io_subchannel_private *io_priv;
struct ccw_device *cdev;
int rc;
if (cio_is_console(sch->schid)) {
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);
/*
* The console subchannel already has an associated ccw_device.
* Throw the delayed uevent for the subchannel, register
* the ccw_device and exit.
*/
dev_set_uevent_suppress(&sch->dev, 0);
kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
cdev = sch_get_cdev(sch);
rc = ccw_device_add(cdev);
if (rc) {
/* Release online reference. */
put_device(&cdev->dev);
goto out_schedule;
}
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
return 0;
}
io_subchannel_init_fields(sch);
rc = cio_commit_config(sch);
if (rc)
goto out_schedule;
rc = sysfs_create_group(&sch->dev.kobj,
&io_subchannel_attr_group);
if (rc)
goto out_schedule;
/* Allocate I/O subchannel private data. */
io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
if (!io_priv)
goto out_schedule;
set_io_private(sch, io_priv);
css_schedule_eval(sch->schid);
return 0;
out_schedule:
spin_lock_irq(sch->lock);
css_sched_sch_todo(sch, SCH_TODO_UNREG);
spin_unlock_irq(sch->lock);
return 0;
}
static int
io_subchannel_remove (struct subchannel *sch)
{
struct io_subchannel_private *io_priv = to_io_private(sch);
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
if (!cdev)
goto out_free;
io_subchannel_quiesce(sch);
/* Set ccw device to not operational and drop reference. */
spin_lock_irq(cdev->ccwlock);
sch_set_cdev(sch, NULL);
set_io_private(sch, NULL);
cdev->private->state = DEV_STATE_NOT_OPER;
spin_unlock_irq(cdev->ccwlock);
ccw_device_unregister(cdev);
out_free:
kfree(io_priv);
sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
return 0;
}
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 void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
if (!cdev)
return;
if (cio_update_schib(sch))
goto err;
/* Check for I/O on path. */
if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
goto out;
if (cdev->private->state == DEV_STATE_ONLINE) {
ccw_device_kill_io(cdev);
goto out;
}
if (cio_clear(sch))
goto err;
out:
/* Trigger path verification. */
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
return;
err:
dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
}
static int io_subchannel_chp_event(struct subchannel *sch,
struct chp_link *link, int event)
{
struct ccw_device *cdev = sch_get_cdev(sch);
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;
if (cdev)
cdev->private->path_gone_mask |= mask;
io_subchannel_terminate_path(sch, mask);
break;
case CHP_VARY_ON:
sch->opm |= mask;
sch->lpm |= mask;
if (cdev)
cdev->private->path_new_mask |= mask;
io_subchannel_verify(sch);
break;
case CHP_OFFLINE:
if (cio_update_schib(sch))
return -ENODEV;
if (cdev)
cdev->private->path_gone_mask |= mask;
io_subchannel_terminate_path(sch, mask);
break;
case CHP_ONLINE:
if (cio_update_schib(sch))
return -ENODEV;
sch->lpm |= mask & sch->opm;
if (cdev)
cdev->private->path_new_mask |= mask;
io_subchannel_verify(sch);
break;
}
return 0;
}
static void io_subchannel_quiesce(struct subchannel *sch)
{
struct ccw_device *cdev;
int ret;
spin_lock_irq(sch->lock);
cdev = sch_get_cdev(sch);
if (cio_is_console(sch->schid))
goto out_unlock;
if (!sch->schib.pmcw.ena)
goto out_unlock;
ret = cio_disable_subchannel(sch);
if (ret != -EBUSY)
goto out_unlock;
if (cdev->handler)
cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
while (ret == -EBUSY) {
cdev->private->state = DEV_STATE_QUIESCE;
cdev->private->iretry = 255;
ret = ccw_device_cancel_halt_clear(cdev);
if (ret == -EBUSY) {
ccw_device_set_timeout(cdev, HZ/10);
spin_unlock_irq(sch->lock);
wait_event(cdev->private->wait_q,
cdev->private->state != DEV_STATE_QUIESCE);
spin_lock_irq(sch->lock);
}
ret = cio_disable_subchannel(sch);
}
out_unlock:
spin_unlock_irq(sch->lock);
}
static void io_subchannel_shutdown(struct subchannel *sch)
{
io_subchannel_quiesce(sch);
}
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);
struct subchannel *sch;
int *redo = data;
spin_lock_irq(cdev->ccwlock);
switch (cdev->private->state) {
case DEV_STATE_ONLINE:
sch = to_subchannel(cdev->dev.parent);
if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
break;
/* fall through */
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(3, "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);
}
void ccw_device_schedule_recovery(void)
{
unsigned long flags;
CIO_MSG_EVENT(3, "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_dev_id *id = &cdev->private->dev_id;
spin_lock_irq(cdev->ccwlock);
if (is_blacklisted(id->ssid, id->devno) &&
(cdev->private->state == DEV_STATE_OFFLINE) &&
(atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
id->devno);
ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
atomic_set(&cdev->private->onoff, 0);
}
spin_unlock_irq(cdev->ccwlock);
/* 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;
}
void ccw_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;
}
enum io_sch_action {
IO_SCH_UNREG,
IO_SCH_ORPH_UNREG,
IO_SCH_ATTACH,
IO_SCH_UNREG_ATTACH,
IO_SCH_ORPH_ATTACH,
IO_SCH_REPROBE,
IO_SCH_VERIFY,
IO_SCH_DISC,
IO_SCH_NOP,
};
static enum io_sch_action sch_get_action(struct subchannel *sch)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
if (cio_update_schib(sch)) {
/* Not operational. */
if (!cdev)
return IO_SCH_UNREG;
if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
return IO_SCH_UNREG;
return IO_SCH_ORPH_UNREG;
}
/* Operational. */
if (!cdev)
return IO_SCH_ATTACH;
if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
return IO_SCH_UNREG_ATTACH;
return IO_SCH_ORPH_ATTACH;
}
if ((sch->schib.pmcw.pam & sch->opm) == 0) {
if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
return IO_SCH_UNREG;
return IO_SCH_DISC;
}
if (device_is_disconnected(cdev))
return IO_SCH_REPROBE;
if (cdev->online && !cdev->private->flags.resuming)
return IO_SCH_VERIFY;
if (cdev->private->state == DEV_STATE_NOT_OPER)
return IO_SCH_UNREG_ATTACH;
return IO_SCH_NOP;
}
/**
* io_subchannel_sch_event - process subchannel event
* @sch: subchannel
* @process: non-zero if function is called in process context
*
* An unspecified event occurred for this subchannel. Adjust data according
* to the current operational state of the subchannel and device. Return
* zero when the event has been handled sufficiently or -EAGAIN when this
* function should be called again in process context.
*/
static int io_subchannel_sch_event(struct subchannel *sch, int process)
{
unsigned long flags;
struct ccw_device *cdev;
struct ccw_dev_id dev_id;
enum io_sch_action action;
int rc = -EAGAIN;
spin_lock_irqsave(sch->lock, flags);
if (!device_is_registered(&sch->dev))
goto out_unlock;
if (work_pending(&sch->todo_work))
goto out_unlock;
cdev = sch_get_cdev(sch);
if (cdev && work_pending(&cdev->private->todo_work))
goto out_unlock;
action = sch_get_action(sch);
CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
sch->schid.ssid, sch->schid.sch_no, process,
action);
/* Perform immediate actions while holding the lock. */
switch (action) {
case IO_SCH_REPROBE:
/* Trigger device recognition. */
ccw_device_trigger_reprobe(cdev);
rc = 0;
goto out_unlock;
case IO_SCH_VERIFY:
/* Trigger path verification. */
io_subchannel_verify(sch);
rc = 0;
goto out_unlock;
case IO_SCH_DISC:
ccw_device_set_disconnected(cdev);
rc = 0;
goto out_unlock;
case IO_SCH_ORPH_UNREG:
case IO_SCH_ORPH_ATTACH:
ccw_device_set_disconnected(cdev);
break;
case IO_SCH_UNREG_ATTACH:
case IO_SCH_UNREG:
if (!cdev)
break;
if (cdev->private->state == DEV_STATE_SENSE_ID) {
/*
* Note: delayed work triggered by this event
* and repeated calls to sch_event are synchronized
* by the above check for work_pending(cdev).
*/
dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
} else
ccw_device_set_notoper(cdev);
break;
case IO_SCH_NOP:
rc = 0;
goto out_unlock;
default:
break;
}
spin_unlock_irqrestore(sch->lock, flags);
/* All other actions require process context. */
if (!process)
goto out;
/* Handle attached ccw device. */
switch (action) {
case IO_SCH_ORPH_UNREG:
case IO_SCH_ORPH_ATTACH:
/* Move ccw device to orphanage. */
rc = ccw_device_move_to_orph(cdev);
if (rc)
goto out;
break;
case IO_SCH_UNREG_ATTACH:
spin_lock_irqsave(sch->lock, flags);
if (cdev->private->flags.resuming) {
/* Device will be handled later. */
rc = 0;
goto out_unlock;
}
sch_set_cdev(sch, NULL);
spin_unlock_irqrestore(sch->lock, flags);
/* Unregister ccw device. */
ccw_device_unregister(cdev);
break;
default:
break;
}
/* Handle subchannel. */
switch (action) {
case IO_SCH_ORPH_UNREG:
case IO_SCH_UNREG:
if (!cdev || !cdev->private->flags.resuming)
css_sch_device_unregister(sch);
break;
case IO_SCH_ORPH_ATTACH:
case IO_SCH_UNREG_ATTACH:
case IO_SCH_ATTACH:
dev_id.ssid = sch->schid.ssid;
dev_id.devno = sch->schib.pmcw.dev;
cdev = get_ccwdev_by_dev_id(&dev_id);
if (!cdev) {
sch_create_and_recog_new_device(sch);
break;
}
rc = ccw_device_move_to_sch(cdev, sch);
if (rc) {
/* Release reference from get_ccwdev_by_dev_id() */
put_device(&cdev->dev);
goto out;
}
spin_lock_irqsave(sch->lock, flags);
ccw_device_trigger_reprobe(cdev);
spin_unlock_irqrestore(sch->lock, flags);
/* Release reference from get_ccwdev_by_dev_id() */
put_device(&cdev->dev);
break;
default:
break;
}
return 0;
out_unlock:
spin_unlock_irqrestore(sch->lock, flags);
out:
return rc;
}
static void ccw_device_set_int_class(struct ccw_device *cdev)
{
struct ccw_driver *cdrv = cdev->drv;
/* Note: we interpret class 0 in this context as an uninitialized
* field since it translates to a non-I/O interrupt class. */
if (cdrv->int_class != 0)
cdev->private->int_class = cdrv->int_class;
else
cdev->private->int_class = IRQIO_CIO;
}
#ifdef CONFIG_CCW_CONSOLE
int __init ccw_device_enable_console(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
int rc;
if (!cdev->drv || !cdev->handler)
return -EINVAL;
io_subchannel_init_fields(sch);
rc = cio_commit_config(sch);
if (rc)
return rc;
sch->driver = &io_subchannel_driver;
io_subchannel_recog(cdev, sch);
/* Now wait for the async. recognition to come to an end. */
spin_lock_irq(cdev->ccwlock);
while (!dev_fsm_final_state(cdev))
ccw_device_wait_idle(cdev);
/* Hold on to an extra reference while device is online. */
get_device(&cdev->dev);
rc = ccw_device_online(cdev);
if (rc)
goto out_unlock;
while (!dev_fsm_final_state(cdev))
ccw_device_wait_idle(cdev);
if (cdev->private->state == DEV_STATE_ONLINE)
cdev->online = 1;
else
rc = -EIO;
out_unlock:
spin_unlock_irq(cdev->ccwlock);
if (rc) /* Give up online reference since onlining failed. */
put_device(&cdev->dev);
return rc;
}
struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
{
struct io_subchannel_private *io_priv;
struct ccw_device *cdev;
struct subchannel *sch;
sch = cio_probe_console();
if (IS_ERR(sch))
return ERR_CAST(sch);
io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
if (!io_priv) {
put_device(&sch->dev);
return ERR_PTR(-ENOMEM);
}
set_io_private(sch, io_priv);
cdev = io_subchannel_create_ccwdev(sch);
if (IS_ERR(cdev)) {
put_device(&sch->dev);
kfree(io_priv);
return cdev;
}
cdev->drv = drv;
ccw_device_set_int_class(cdev);
return cdev;
}
void __init ccw_device_destroy_console(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct io_subchannel_private *io_priv = to_io_private(sch);
set_io_private(sch, NULL);
put_device(&sch->dev);
put_device(&cdev->dev);
kfree(io_priv);
}
/**
* ccw_device_wait_idle() - busy wait for device to become idle
* @cdev: ccw device
*
* Poll until activity control is zero, that is, no function or data
* transfer is pending/active.
* Called with device lock being held.
*/
void ccw_device_wait_idle(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
while (1) {
cio_tsch(sch);
if (sch->schib.scsw.cmd.actl == 0)
break;
udelay_simple(100);
}
}
static int ccw_device_pm_restore(struct device *dev);
int ccw_device_force_console(struct ccw_device *cdev)
{
return ccw_device_pm_restore(&cdev->dev);
}
EXPORT_SYMBOL_GPL(ccw_device_force_console);
#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;
dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
__ccwdev_check_busid);
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 */
ccw_device_set_int_class(cdev);
ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
if (ret) {
cdev->drv = NULL;
cdev->private->int_class = IRQIO_CIO;
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);
spin_lock_irq(cdev->ccwlock);
if (cdev->online) {
cdev->online = 0;
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);
spin_lock_irq(cdev->ccwlock);
}
ccw_device_set_timeout(cdev, 0);
cdev->drv = NULL;
cdev->private->int_class = IRQIO_CIO;
spin_unlock_irq(cdev->ccwlock);
__disable_cmf(cdev);
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);
}
static int ccw_device_pm_prepare(struct device *dev)
{
struct ccw_device *cdev = to_ccwdev(dev);
if (work_pending(&cdev->private->todo_work))
return -EAGAIN;
/* Fail while device is being set online/offline. */
if (atomic_read(&cdev->private->onoff))
return -EAGAIN;
if (cdev->online && cdev->drv && cdev->drv->prepare)
return cdev->drv->prepare(cdev);
return 0;
}
static void ccw_device_pm_complete(struct device *dev)
{
struct ccw_device *cdev = to_ccwdev(dev);
if (cdev->online && cdev->drv && cdev->drv->complete)
cdev->drv->complete(cdev);
}
static int ccw_device_pm_freeze(struct device *dev)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct subchannel *sch = to_subchannel(cdev->dev.parent);
int ret, cm_enabled;
/* Fail suspend while device is in transistional state. */
if (!dev_fsm_final_state(cdev))
return -EAGAIN;
if (!cdev->online)
return 0;
if (cdev->drv && cdev->drv->freeze) {
ret = cdev->drv->freeze(cdev);
if (ret)
return ret;
}
spin_lock_irq(sch->lock);
cm_enabled = cdev->private->cmb != NULL;
spin_unlock_irq(sch->lock);
if (cm_enabled) {
/* Don't have the css write on memory. */
ret = ccw_set_cmf(cdev, 0);
if (ret)
return ret;
}
/* From here on, disallow device driver I/O. */
spin_lock_irq(sch->lock);
ret = cio_disable_subchannel(sch);
spin_unlock_irq(sch->lock);
return ret;
}
static int ccw_device_pm_thaw(struct device *dev)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct subchannel *sch = to_subchannel(cdev->dev.parent);
int ret, cm_enabled;
if (!cdev->online)
return 0;
spin_lock_irq(sch->lock);
/* Allow device driver I/O again. */
ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
cm_enabled = cdev->private->cmb != NULL;
spin_unlock_irq(sch->lock);
if (ret)
return ret;
if (cm_enabled) {
ret = ccw_set_cmf(cdev, 1);
if (ret)
return ret;
}
if (cdev->drv && cdev->drv->thaw)
ret = cdev->drv->thaw(cdev);
return ret;
}
static void __ccw_device_pm_restore(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
spin_lock_irq(sch->lock);
if (cio_is_console(sch->schid)) {
cio_enable_subchannel(sch, (u32)(addr_t)sch);
goto out_unlock;
}
/*
* While we were sleeping, devices may have gone or become
* available again. Kick re-detection.
*/
cdev->private->flags.resuming = 1;
cdev->private->path_new_mask = LPM_ANYPATH;
css_sched_sch_todo(sch, SCH_TODO_EVAL);
spin_unlock_irq(sch->lock);
css_wait_for_slow_path();
/* cdev may have been moved to a different subchannel. */
sch = to_subchannel(cdev->dev.parent);
spin_lock_irq(sch->lock);
if (cdev->private->state != DEV_STATE_ONLINE &&
cdev->private->state != DEV_STATE_OFFLINE)
goto out_unlock;
ccw_device_recognition(cdev);
spin_unlock_irq(sch->lock);
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
cdev->private->state == DEV_STATE_DISCONNECTED);
spin_lock_irq(sch->lock);
out_unlock:
cdev->private->flags.resuming = 0;
spin_unlock_irq(sch->lock);
}
static int resume_handle_boxed(struct ccw_device *cdev)
{
cdev->private->state = DEV_STATE_BOXED;
if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
return 0;
ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
return -ENODEV;
}
static int resume_handle_disc(struct ccw_device *cdev)
{
cdev->private->state = DEV_STATE_DISCONNECTED;
if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
return 0;
ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
return -ENODEV;
}
static int ccw_device_pm_restore(struct device *dev)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct subchannel *sch;
int ret = 0;
__ccw_device_pm_restore(cdev);
sch = to_subchannel(cdev->dev.parent);
spin_lock_irq(sch->lock);
if (cio_is_console(sch->schid))
goto out_restore;
/* check recognition results */
switch (cdev->private->state) {
case DEV_STATE_OFFLINE:
case DEV_STATE_ONLINE:
cdev->private->flags.donotify = 0;
break;
case DEV_STATE_BOXED:
ret = resume_handle_boxed(cdev);
if (ret)
goto out_unlock;
goto out_restore;
default:
ret = resume_handle_disc(cdev);
if (ret)
goto out_unlock;
goto out_restore;
}
/* check if the device type has changed */
if (!ccw_device_test_sense_data(cdev)) {
ccw_device_update_sense_data(cdev);
ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
ret = -ENODEV;
goto out_unlock;
}
if (!cdev->online)
goto out_unlock;
if (ccw_device_online(cdev)) {
ret = resume_handle_disc(cdev);
if (ret)
goto out_unlock;
goto out_restore;
}
spin_unlock_irq(sch->lock);
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
spin_lock_irq(sch->lock);
if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
ret = -ENODEV;
goto out_unlock;
}
/* reenable cmf, if needed */
if (cdev->private->cmb) {
spin_unlock_irq(sch->lock);
ret = ccw_set_cmf(cdev, 1);
spin_lock_irq(sch->lock);
if (ret) {
CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
"(rc=%d)\n", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
ret = 0;
}
}
out_restore:
spin_unlock_irq(sch->lock);
if (cdev->online && cdev->drv && cdev->drv->restore)
ret = cdev->drv->restore(cdev);
return ret;
out_unlock:
spin_unlock_irq(sch->lock);
return ret;
}
static const struct dev_pm_ops ccw_pm_ops = {
.prepare = ccw_device_pm_prepare,
.complete = ccw_device_pm_complete,
.freeze = ccw_device_pm_freeze,
.thaw = ccw_device_pm_thaw,
.restore = ccw_device_pm_restore,
};
static 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,
.pm = &ccw_pm_ops,
};
/**
* 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;
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);
}
static void ccw_device_todo(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
struct subchannel *sch;
enum cdev_todo todo;
priv = container_of(work, struct ccw_device_private, todo_work);
cdev = priv->cdev;
sch = to_subchannel(cdev->dev.parent);
/* Find out todo. */
spin_lock_irq(cdev->ccwlock);
todo = priv->todo;
priv->todo = CDEV_TODO_NOTHING;
CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
priv->dev_id.ssid, priv->dev_id.devno, todo);
spin_unlock_irq(cdev->ccwlock);
/* Perform todo. */
switch (todo) {
case CDEV_TODO_ENABLE_CMF:
cmf_reenable(cdev);
break;
case CDEV_TODO_REBIND:
ccw_device_do_unbind_bind(cdev);
break;
case CDEV_TODO_REGISTER:
io_subchannel_register(cdev);
break;
case CDEV_TODO_UNREG_EVAL:
if (!sch_is_pseudo_sch(sch))
css_schedule_eval(sch->schid);
/* fall-through */
case CDEV_TODO_UNREG:
if (sch_is_pseudo_sch(sch))
ccw_device_unregister(cdev);
else
ccw_device_call_sch_unregister(cdev);
break;
default:
break;
}
/* Release workqueue ref. */
put_device(&cdev->dev);
}
/**
* ccw_device_sched_todo - schedule ccw device operation
* @cdev: ccw device
* @todo: todo
*
* Schedule the operation identified by @todo to be performed on the slow path
* workqueue. Do nothing if another operation with higher priority is already
* scheduled. Needs to be called with ccwdev lock held.
*/
void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
{
CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
todo);
if (cdev->private->todo >= todo)
return;
cdev->private->todo = todo;
/* Get workqueue ref. */
if (!get_device(&cdev->dev))
return;
if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
/* Already queued, release workqueue ref. */
put_device(&cdev->dev);
}
}
/**
* ccw_device_siosl() - initiate logging
* @cdev: ccw device
*
* This function is used to invoke model-dependent logging within the channel
* subsystem.
*/
int ccw_device_siosl(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
return chsc_siosl(sch->schid);
}
EXPORT_SYMBOL_GPL(ccw_device_siosl);
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);
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