[S390] cio: introduce parent-initiated device move
Change the initiative to update subchannel-ccw device associations
to the subchannel: when there is an indication that the internal
association no longer reflects the current hardware state, mark
each affected subchannel as requiring attention. Once processing
reaches a subchannel, determine the correct association for that
subchannel at that time and perform the necessary device_move
operations.
This change fixes problems with the previous approach which would
leave devices in an inconsistent state when a new hardware change
occurred while a device_move was already scheduled.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 91c2570..b4df5a5 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -376,8 +376,8 @@
/* Unusable - ignore. */
return 0;
}
- CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
- "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
+ CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
+ schid.sch_no);
return css_probe_device(schid);
}
@@ -394,6 +394,10 @@
"Got subchannel machine check but "
"no sch_event handler provided.\n");
}
+ if (ret != 0 && ret != -EAGAIN) {
+ CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
+ sch->schid.ssid, sch->schid.sch_no, ret);
+ }
return ret;
}
@@ -684,6 +688,7 @@
css->pseudo_subchannel->dev.parent = &css->device;
css->pseudo_subchannel->dev.release = css_subchannel_release;
dev_set_name(&css->pseudo_subchannel->dev, "defunct");
+ mutex_init(&css->pseudo_subchannel->reg_mutex);
ret = cio_create_sch_lock(css->pseudo_subchannel);
if (ret) {
kfree(css->pseudo_subchannel);