[S390] Support for disconnected devices reappearing on another subchannel.
- create a 'pseudo_subchannel' per channel subsystem (the 'orphanage')
- use the orphanage as a shelter for ccw_devices that can't remain on the same
subchannel
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 65939e2..0bf7166 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -580,12 +580,24 @@
static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
-static inline void __init
-setup_css(int nr)
+static inline int __init setup_css(int nr)
{
u32 tod_high;
+ int ret;
memset(css[nr], 0, sizeof(struct channel_subsystem));
+ css[nr]->pseudo_subchannel =
+ kzalloc(sizeof(*css[nr]->pseudo_subchannel), GFP_KERNEL);
+ if (!css[nr]->pseudo_subchannel)
+ return -ENOMEM;
+ css[nr]->pseudo_subchannel->dev.parent = &css[nr]->device;
+ css[nr]->pseudo_subchannel->dev.release = css_subchannel_release;
+ sprintf(css[nr]->pseudo_subchannel->dev.bus_id, "defunct");
+ ret = cio_create_sch_lock(css[nr]->pseudo_subchannel);
+ if (ret) {
+ kfree(css[nr]->pseudo_subchannel);
+ return ret;
+ }
mutex_init(&css[nr]->mutex);
css[nr]->valid = 1;
css[nr]->cssid = nr;
@@ -593,6 +605,7 @@
css[nr]->device.release = channel_subsystem_release;
tod_high = (u32) (get_clock() >> 32);
css_generate_pgid(css[nr], tod_high);
+ return 0;
}
/*
@@ -629,10 +642,12 @@
ret = -ENOMEM;
goto out_unregister;
}
- setup_css(i);
- ret = device_register(&css[i]->device);
+ ret = setup_css(i);
if (ret)
goto out_free;
+ ret = device_register(&css[i]->device);
+ if (ret)
+ goto out_free_all;
if (css_characteristics_avail &&
css_chsc_characteristics.secm) {
ret = device_create_file(&css[i]->device,
@@ -640,6 +655,9 @@
if (ret)
goto out_device;
}
+ ret = device_register(&css[i]->pseudo_subchannel->dev);
+ if (ret)
+ goto out_file;
}
css_init_done = 1;
@@ -647,13 +665,19 @@
for_each_subchannel(__init_channel_subsystem, NULL);
return 0;
+out_file:
+ device_remove_file(&css[i]->device, &dev_attr_cm_enable);
out_device:
device_unregister(&css[i]->device);
+out_free_all:
+ kfree(css[i]->pseudo_subchannel->lock);
+ kfree(css[i]->pseudo_subchannel);
out_free:
kfree(css[i]);
out_unregister:
while (i > 0) {
i--;
+ device_unregister(&css[i]->pseudo_subchannel->dev);
if (css_characteristics_avail && css_chsc_characteristics.secm)
device_remove_file(&css[i]->device,
&dev_attr_cm_enable);
@@ -665,6 +689,11 @@
return ret;
}
+int sch_is_pseudo_sch(struct subchannel *sch)
+{
+ return sch == to_css(sch->dev.parent)->pseudo_subchannel;
+}
+
/*
* find a driver for a subchannel. They identify by the subchannel
* type with the exception that the console subchannel driver has its own