device.c

linux 内核源代码

}

static ssize_t online_store (struct device *dev, struct device_attribute *attr,
			     const char *buf, size_t count)
{
	struct ccw_device *cdev = to_ccwdev(dev);
	int i, force;
	char *tmp;

	if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
		return -EAGAIN;

	if (cdev->drv && !try_module_get(cdev->drv->owner)) {
		atomic_set(&cdev->private->onoff, 0);
		return -EINVAL;
	}
	if (!strncmp(buf, "force\n", count)) {
		force = 1;
		i = 1;
	} else {
		force = 0;
		i = simple_strtoul(buf, &tmp, 16);
	}

	switch (i) {
	case 0:
		online_store_handle_offline(cdev);
		break;
	case 1:
		online_store_handle_online(cdev, force);
		break;
	default:
		count = -EINVAL;
	}
	if (cdev->drv)
		module_put(cdev->drv->owner);
	atomic_set(&cdev->private->onoff, 0);
	return count;
}

static ssize_t
available_show (struct device *dev, struct device_attribute *attr, char *buf)
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct subchannel *sch;

	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);
extern struct device_attribute dev_attr_cmb_enable;
static DEVICE_ATTR(availability, 0444, available_show, NULL);

static struct attribute * subch_attrs[] = {
	&dev_attr_chpids.attr,
	&dev_attr_pimpampom.attr,
	NULL,
};

static struct attribute_group subch_attr_group = {
	.attrs = subch_attrs,
};

struct attribute_group *subch_attr_groups[] = {
	&subch_attr_group,
	NULL,
};

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);
	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)) {
		if (cdev->dev.release)
			cdev->dev.release(&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->dev.driver_data = cdev;
	cdev->private->schid = sch->schid;
	cdev->ccwlock = sch->lock;
	device_trigger_reprobe(sch);
	spin_unlock_irq(sch->lock);
}

static void sch_attach_disconnected_device(struct subchannel *sch,
					   struct ccw_device *cdev)
{
	struct subchannel *other_sch;
	int ret;

	other_sch = to_subchannel(get_device(cdev->dev.parent));
	ret = device_move(&cdev->dev, &sch->dev);
	if (ret) {
		CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
			      "(ret=%d)!\n", cdev->private->dev_id.ssid,
			      cdev->private->dev_id.devno, ret);
		put_device(&other_sch->dev);
		return;
	}
	other_sch->dev.driver_data = NULL;
	/* No need to keep a subchannel without ccw device around. */
	css_sch_device_unregister(other_sch);
	put_device(&other_sch->dev);
	sch_attach_device(sch, cdev);
}

static void sch_attach_orphaned_device(struct subchannel *sch,
				       struct ccw_device *cdev)
{
	int ret;

	/* Try to move the ccw device to its new subchannel. */
	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);
		return;
	}
	sch_attach_device(sch, cdev);
}

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->dev.driver_data = 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->dev.driver_data = NULL;
		spin_unlock_irq(sch->lock);
		if (cdev->dev.release)
			cdev->dev.release(&cdev->dev);
		css_sch_device_unregister(sch);
	}
}


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;

	/*
	 * Move the orphaned ccw device to the orphanage so the replacing
	 * ccw device can take its place on the subchannel.
	 */
	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);
		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);
		return;
	}
	replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
	if (replacing_cdev) {
		sch_attach_orphaned_device(sch, replacing_cdev);
		return;
	}
	sch_create_and_recog_new_device(sch);
}

/*
 * 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);
	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 (klist_node_attached(&cdev->dev.knode_parent)) {
		if (!cdev->drv) {
			ret = device_reprobe(&cdev->dev);
			if (ret)
				/* We can't do much here. */
				CIO_MSG_EVENT(2, "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);
		put_device(&cdev->dev);
		spin_lock_irqsave(sch->lock, flags);
		sch->dev.driver_data = NULL;
		spin_unlock_irqrestore(sch->lock, flags);
		kfree (cdev->private);
		kfree (cdev);
		put_device(&sch->dev);
		if (atomic_dec_and_test(&ccw_device_init_count))
			wake_up(&ccw_device_init_wq);
		return;
	}
	put_device(&cdev->dev);
out:
	cdev->private->flags.recog_done = 1;
	put_device(&sch->dev);
	wake_up(&cdev->private->wait_q);
	if (atomic_dec_and_test(&ccw_device_init_count))
		wake_up(&ccw_device_init_wq);
}

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;
	sch = to_subchannel(cdev->dev.parent);
	css_sch_device_unregister(sch);
	/* Reset intparm to zeroes. */
	sch->schib.pmcw.intparm = 0;
	cio_modify(sch);
	put_device(&cdev->dev);
	put_device(&sch->dev);
}

/*
 * subchannel recognition done. Called from the state machine.
 */
void
io_subchannel_recog_done(struct ccw_device *cdev)
{
	struct subchannel *sch;

	if (css_init_done == 0) {
		cdev->private->flags.recog_done = 1;
		return;
	}
	switch (cdev->private->state) {
	case DEV_STATE_NOT_OPER:
		cdev->private->flags.recog_done = 1;
		/* Remove device found not operational. */
		if (!get_device(&cdev->dev))
			break;
		sch = to_subchannel(cdev->dev.parent);