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path: root/drivers/s390/cio/css.c
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Diffstat (limited to 'drivers/s390/cio/css.c')
-rw-r--r--drivers/s390/cio/css.c57
1 files changed, 55 insertions, 2 deletions
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 91c25706fa83..92ff88ac1107 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -133,6 +133,8 @@ out:
return rc;
}
+static void css_sch_todo(struct work_struct *work);
+
static struct subchannel *
css_alloc_subchannel(struct subchannel_id schid)
{
@@ -147,6 +149,7 @@ css_alloc_subchannel(struct subchannel_id schid)
kfree(sch);
return ERR_PTR(ret);
}
+ INIT_WORK(&sch->todo_work, css_sch_todo);
return sch;
}
@@ -190,6 +193,51 @@ void css_sch_device_unregister(struct subchannel *sch)
}
EXPORT_SYMBOL_GPL(css_sch_device_unregister);
+static void css_sch_todo(struct work_struct *work)
+{
+ struct subchannel *sch;
+ enum sch_todo todo;
+
+ sch = container_of(work, struct subchannel, todo_work);
+ /* Find out todo. */
+ spin_lock_irq(sch->lock);
+ todo = sch->todo;
+ CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
+ sch->schid.sch_no, todo);
+ sch->todo = SCH_TODO_NOTHING;
+ spin_unlock_irq(sch->lock);
+ /* Perform todo. */
+ if (todo == SCH_TODO_UNREG)
+ css_sch_device_unregister(sch);
+ /* Release workqueue ref. */
+ put_device(&sch->dev);
+}
+
+/**
+ * css_sched_sch_todo - schedule a subchannel operation
+ * @sch: subchannel
+ * @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 subchannel lock held.
+ */
+void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
+{
+ CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
+ sch->schid.ssid, sch->schid.sch_no, todo);
+ if (sch->todo >= todo)
+ return;
+ /* Get workqueue ref. */
+ if (!get_device(&sch->dev))
+ return;
+ sch->todo = todo;
+ if (!queue_work(slow_path_wq, &sch->todo_work)) {
+ /* Already queued, release workqueue ref. */
+ put_device(&sch->dev);
+ }
+}
+
static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
{
int i;
@@ -376,8 +424,8 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
/* 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 +442,10 @@ static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
"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 +736,7 @@ static int __init setup_css(int nr)
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);