From: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Date: Wed, 21 Mar 2018 16:17:14 +0000 (+0100)
Subject: s390/qdio: lock device while installing IRQ handler
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7eee12b44eb4c0c30b0eac5946fb59f1460572f6;p=linux.git

s390/qdio: lock device while installing IRQ handler

During setup, qdio takes control of the presented ccw device and replaces
the device's IRQ handler with its own. To avoid any interference with
conccurent activity on the device, this should be done while holding the
device's lock.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c
index 98f3cfdc0d027..439991d71b146 100644
--- a/drivers/s390/cio/qdio_setup.c
+++ b/drivers/s390/cio/qdio_setup.c
@@ -507,8 +507,10 @@ int qdio_setup_irq(struct qdio_initialize *init_data)
 	irq_ptr->aqueue = *ciw;
 
 	/* set new interrupt handler */
+	spin_lock_irq(get_ccwdev_lock(irq_ptr->cdev));
 	irq_ptr->orig_handler = init_data->cdev->handler;
 	init_data->cdev->handler = qdio_int_handler;
+	spin_unlock_irq(get_ccwdev_lock(irq_ptr->cdev));
 	return 0;
 out_err:
 	qdio_release_memory(irq_ptr);