Commit 3a232277 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio-ccw: implement synchronize_cbs() 



This patch tries to implement the synchronize_cbs() for ccw. For the
vring_interrupt() that is called via virtio_airq_handler(), the
synchronization is simply done via the airq_info's lock. For the
vring_interrupt() that is called via virtio_ccw_int_handler(), a per
device rwlock is introduced and used in the synchronization method.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Vineeth Vijayan <vneethv@linux.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Reviewed-by: default avatarHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Message-Id: <20220527060120.20964-7-jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 9e9b2893

drivers/s390/virtio/virtio_ccw.c

+30 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ struct virtio_ccw_device { 
	unsigned int revision; /* Transport revision */

	wait_queue_head_t wait_q;

	spinlock_t lock;

	rwlock_t irq_lock;

	struct mutex io_lock; /* Serializes I/O requests */

	struct list_head virtqueues;

	bool is_thinint;
@@ -984,6 +985,30 @@ static const char *virtio_ccw_bus_name(struct virtio_device *vdev) 
	return dev_name(&vcdev->cdev->dev);

}



static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	struct airq_info *info = vcdev->airq_info;



	if (info) {

		/*

		 * This device uses adapter interrupts: synchronize with

		 * vring_interrupt() called by virtio_airq_handler()

		 * via the indicator area lock.

		 */

		write_lock_irq(&info->lock);

		write_unlock_irq(&info->lock);

	} else {

		/* This device uses classic interrupts: synchronize

		 * with vring_interrupt() called by

		 * virtio_ccw_int_handler() via the per-device

		 * irq_lock

		 */

		write_lock_irq(&vcdev->irq_lock);

		write_unlock_irq(&vcdev->irq_lock);

	}

}



static const struct virtio_config_ops virtio_ccw_config_ops = {

	.get_features = virtio_ccw_get_features,

	.finalize_features = virtio_ccw_finalize_features,
@@ -995,6 +1020,7 @@ static const struct virtio_config_ops virtio_ccw_config_ops = { 
	.find_vqs = virtio_ccw_find_vqs,

	.del_vqs = virtio_ccw_del_vqs,

	.bus_name = virtio_ccw_bus_name,

	.synchronize_cbs = virtio_ccw_synchronize_cbs,

};
@@ -1106,6 +1132,8 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev, 
			vcdev->err = -EIO;

	}

	virtio_ccw_check_activity(vcdev, activity);

	/* Interrupts are disabled here */

	read_lock(&vcdev->irq_lock);

	for_each_set_bit(i, indicators(vcdev),

			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {

		/* The bit clear must happen before the vring kick. */
@@ -1114,6 +1142,7 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev, 
		vq = virtio_ccw_vq_by_ind(vcdev, i);

		vring_interrupt(0, vq);

	}

	read_unlock(&vcdev->irq_lock);

	if (test_bit(0, indicators2(vcdev))) {

		virtio_config_changed(&vcdev->vdev);

		clear_bit(0, indicators2(vcdev));
@@ -1284,6 +1313,7 @@ static int virtio_ccw_online(struct ccw_device *cdev) 
	init_waitqueue_head(&vcdev->wait_q);

	INIT_LIST_HEAD(&vcdev->virtqueues);

	spin_lock_init(&vcdev->lock);

	rwlock_init(&vcdev->irq_lock);

	mutex_init(&vcdev->io_lock);



	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);