linux-kernel - [PATCH v12 04/17] s390/vfio-ap: No need to disable IRQ after queue reset

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Date:   Tue, 24 Nov 2020 16:40:03 -0500
From:   Tony Krowiak <akrowiak@...ux.ibm.com>
To:     linux-s390@...r.kernel.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Cc:     freude@...ux.ibm.com, borntraeger@...ibm.com, cohuck@...hat.com,
        mjrosato@...ux.ibm.com, pasic@...ux.ibm.com,
        alex.williamson@...hat.com, kwankhede@...dia.com,
        fiuczy@...ux.ibm.com, frankja@...ux.ibm.com, david@...hat.com,
        hca@...ux.ibm.com, gor@...ux.ibm.com,
        Tony Krowiak <akrowiak@...ux.ibm.com>
Subject: [PATCH v12 04/17] s390/vfio-ap: No need to disable IRQ after queue reset

The queues assigned to a matrix mediated device are currently reset when:

* The VFIO_DEVICE_RESET ioctl is invoked
* The mdev fd is closed by userspace (QEMU)
* The mdev is removed from sysfs.

Immediately after the reset of a queue, a call is made to disable
interrupts for the queue. This is entirely unnecessary because the reset of
a queue disables interrupts, so this will be removed.

Signed-off-by: Tony Krowiak <akrowiak@...ux.ibm.com>
---
 drivers/s390/crypto/vfio_ap_ops.c | 28 +++++-----------------------
 1 file changed, 5 insertions(+), 23 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 8e6972495daa..dc699fd54505 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -26,14 +26,6 @@
 
 static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev);
 
-static int match_apqn(struct device *dev, const void *data)
-{
-	struct vfio_ap_queue *q = dev_get_drvdata(dev);
-
-	return (q->apqn == *(int *)(data)) ? 1 : 0;
-}
-
-
 /**
  * vfio_ap_get_queue: Retrieve a queue with a specific APQN.
  * @matrix_mdev: the associated mediated matrix
@@ -1121,20 +1113,6 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
-static void vfio_ap_irq_disable_apqn(int apqn)
-{
-	struct device *dev;
-	struct vfio_ap_queue *q;
-
-	dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
-				 &apqn, match_apqn);
-	if (dev) {
-		q = dev_get_drvdata(dev);
-		vfio_ap_irq_disable(q);
-		put_device(dev);
-	}
-}
-
 static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
 				    unsigned int retry)
 {
@@ -1169,6 +1147,7 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
 {
 	int ret;
 	int rc = 0;
+	struct vfio_ap_queue *q;
 	unsigned long apid, apqi;
 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
 
@@ -1184,7 +1163,10 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
 			 */
 			if (ret)
 				rc = ret;
-			vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi));
+
+			q = vfio_ap_get_queue(matrix_mdev, AP_MKQID(apid, apqi);
+			if (q)
+				vfio_ap_free_aqic_resources(q);
 		}
 	}
 
-- 
2.21.1