4 files changed, 72 insertions, 36 deletions

diff --git a/drivers/s390/cio/blacklist.c b/drivers/s390/cio/blacklist.c
index 0960bef7b199..15b895496a45 100644
--- a/drivers/s390/cio/blacklist.c
+++ b/drivers/s390/cio/blacklist.c
@@ -224,39 +224,6 @@ is_blacklisted (int ssid, int devno)
 }
 
 #ifdef CONFIG_PROC_FS
-static int
-__s390_redo_validation(struct subchannel_id schid, void *data)
-{
-	int ret;
-	struct subchannel *sch;
-
-	sch = get_subchannel_by_schid(schid);
-	if (sch) {
-		/* Already known. */
-		put_device(&sch->dev);
-		return 0;
-	}
-	ret = css_probe_device(schid);
-	if (ret == -ENXIO)
-		return ret; /* We're through. */
-	if (ret == -ENOMEM)
-		/* Stop validation for now. Bad, but no need for a panic. */
-		return ret;
-	return 0;
-}
-
-/*
- * Function: s390_redo_validation
- * Look for no longer blacklisted devices
- * FIXME: there must be a better way to do this */
-static inline void
-s390_redo_validation (void)
-{
-	CIO_TRACE_EVENT (0, "redoval");
-
-	for_each_subchannel(__s390_redo_validation, NULL);
-}
-
 /*
  * Function: blacklist_parse_proc_parameters
  * parse the stuff which is piped to /proc/cio_ignore
@@ -281,7 +248,7 @@ blacklist_parse_proc_parameters (char *buf)
 		return;
 	}
 
-	s390_redo_validation ();
+	css_schedule_reprobe();
 }
 
 /* Iterator struct for all devices. */
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 74ea8aac4b7d..1d3be80797f8 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -19,9 +19,11 @@
 #include "cio_debug.h"
 #include "ioasm.h"
 #include "chsc.h"
+#include "device.h"
 
 int need_rescan = 0;
 int css_init_done = 0;
+static int need_reprobe = 0;
 static int max_ssid = 0;
 
 struct channel_subsystem *css[__MAX_CSSID + 1];
@@ -339,6 +341,67 @@ typedef void (*workfunc)(void *);
 DECLARE_WORK(slow_path_work, (workfunc)css_trigger_slow_path, NULL);
 struct workqueue_struct *slow_path_wq;
 
+/* Reprobe subchannel if unregistered. */
+static int reprobe_subchannel(struct subchannel_id schid, void *data)
+{
+	struct subchannel *sch;
+	int ret;
+
+	CIO_DEBUG(KERN_INFO, 6, "cio: reprobe 0.%x.%04x\n",
+		  schid.ssid, schid.sch_no);
+	if (need_reprobe)
+		return -EAGAIN;
+
+	sch = get_subchannel_by_schid(schid);
+	if (sch) {
+		/* Already known. */
+		put_device(&sch->dev);
+		return 0;
+	}
+
+	ret = css_probe_device(schid);
+	switch (ret) {
+	case 0:
+		break;
+	case -ENXIO:
+	case -ENOMEM:
+		/* These should abort looping */
+		break;
+	default:
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/* Work function used to reprobe all unregistered subchannels. */
+static void reprobe_all(void *data)
+{
+	int ret;
+
+	CIO_MSG_EVENT(2, "reprobe start\n");
+
+	need_reprobe = 0;
+	/* Make sure initial subchannel scan is done. */
+	wait_event(ccw_device_init_wq,
+		   atomic_read(&ccw_device_init_count) == 0);
+	ret = for_each_subchannel(reprobe_subchannel, NULL);
+
+	CIO_MSG_EVENT(2, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
+		      need_reprobe);
+}
+
+DECLARE_WORK(css_reprobe_work, reprobe_all, NULL);
+
+/* Schedule reprobing of all unregistered subchannels. */
+void css_schedule_reprobe(void)
+{
+	need_reprobe = 1;
+	queue_work(ccw_device_work, &css_reprobe_work);
+}
+
+EXPORT_SYMBOL_GPL(css_schedule_reprobe);
+
 /*
  * Rescan for new devices. FIXME: This is slow.
  * This function is called when we have lost CRWs due to overflows and we have
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 8e3053c2a451..eafde43e8410 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -133,8 +133,8 @@ struct css_driver io_subchannel_driver = {
 
 struct workqueue_struct *ccw_device_work;
 struct workqueue_struct *ccw_device_notify_work;
-static wait_queue_head_t ccw_device_init_wq;
-static atomic_t ccw_device_init_count;
+wait_queue_head_t ccw_device_init_wq;
+atomic_t ccw_device_init_count;
 
 static int __init
 init_ccw_bus_type (void)
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 11587ebb7289..8e0d1db3dd4e 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -1,6 +1,10 @@
 #ifndef S390_DEVICE_H
 #define S390_DEVICE_H
 
+#include <asm/ccwdev.h>
+#include <asm/atomic.h>
+#include <linux/wait.h>
+
 /*
  * states of the device statemachine
  */
@@ -67,6 +71,8 @@ dev_fsm_final_state(struct ccw_device *cdev)
 
 extern struct workqueue_struct *ccw_device_work;
 extern struct workqueue_struct *ccw_device_notify_work;
+extern wait_queue_head_t ccw_device_init_wq;
+extern atomic_t ccw_device_init_count;
 
 void io_subchannel_recog_done(struct ccw_device *cdev);