s390/cio: wait_cons_dev don't use static variable

wait_cons_dev is used to busy wait for an interrupt on the console
ccw device. Stop using the static console_subchannel and add a
parameter to this function to specify on which ccw device/subchannel
we have to do the polling.

While at it rename the function to ccw_device_wait_idle and
move it to device.c

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 28 insertions, 20 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 986ef6a92a41..2c1d53fb2fab 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -656,9 +656,9 @@ static int console_subchannel_in_use;
 
 /*
  * Use cio_tsch to update the subchannel status and call the interrupt handler
- * if status had been pending. Called with the console_subchannel lock.
+ * if status had been pending. Called with the subchannel's lock held.
  */
-static void cio_tsch(struct subchannel *sch)
+void cio_tsch(struct subchannel *sch)
 {
 	struct irb *irb;
 	int irq_context;
@@ -690,22 +690,6 @@ void *cio_get_console_priv(void)
 	return &console_priv;
 }
 
-/*
- * busy wait for the next interrupt on the console
- */
-void wait_cons_dev(void)
-{
-	if (!console_subchannel_in_use)
-		return;
-
-	while (1) {
-		cio_tsch(&console_subchannel);
-		if (console_subchannel.schib.scsw.cmd.actl == 0)
-			break;
-		udelay_simple(100);
-	}
-}
-
 static int
 cio_test_for_console(struct subchannel_id schid, void *data)
 {
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 4a1ff5c2eb88..3b97c8bb30e5 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -133,6 +133,7 @@ extern int cio_is_console(struct subchannel_id);
 extern struct subchannel *cio_get_console_subchannel(void);
 extern spinlock_t * cio_get_console_lock(void);
 extern void *cio_get_console_priv(void);
+extern void cio_tsch(struct subchannel *sch);
 #else
 #define cio_is_console(schid) 0
 #define cio_get_console_subchannel() NULL
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index c6767f5a58b2..2e1e9086e916 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -19,6 +19,7 @@
 #include <linux/list.h>
 #include <linux/device.h>
 #include <linux/workqueue.h>
+#include <linux/delay.h>
 #include <linux/timer.h>
 #include <linux/kernel_stat.h>
 
@@ -1612,13 +1613,15 @@ static int ccw_device_console_enable(struct ccw_device *cdev,
 	/* Now wait for the async. recognition to come to an end. */
 	spin_lock_irq(cdev->ccwlock);
 	while (!dev_fsm_final_state(cdev))
-		wait_cons_dev();
+		ccw_device_wait_idle(cdev);
+
 	rc = -EIO;
 	if (cdev->private->state != DEV_STATE_OFFLINE)
 		goto out_unlock;
 	ccw_device_online(cdev);
 	while (!dev_fsm_final_state(cdev))
-		wait_cons_dev();
+		ccw_device_wait_idle(cdev);
+
 	if (cdev->private->state != DEV_STATE_ONLINE)
 		goto out_unlock;
 	rc = 0;
@@ -1655,6 +1658,26 @@ ccw_device_probe_console(void)
 	return &console_cdev;
 }
 
+/**
+ * ccw_device_wait_idle() - busy wait for device to become idle
+ * @cdev: ccw device
+ *
+ * Poll until activity control is zero, that is, no function or data
+ * transfer is pending/active.
+ * Called with device lock being held.
+ */
+void ccw_device_wait_idle(struct ccw_device *cdev)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+	while (1) {
+		cio_tsch(sch);
+		if (sch->schib.scsw.cmd.actl == 0)
+			break;
+		udelay_simple(100);
+	}
+}
+
 static int ccw_device_pm_restore(struct device *dev);
 
 int ccw_device_force_console(void)