[PATCH V5 7/9] virtio: allow to unbreak virtqueue
From: Jason Wang <hidden>
Date: 2022-05-18 04:06:05
Also in:
linux-s390, lkml
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
This patch allows the new introduced __virtio_break_device() to unbreak the virtqueue. Cc: Thomas Gleixner <redacted> 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 Signed-off-by: Jason Wang <redacted> --- drivers/virtio/virtio_ring.c | 21 +++++++++++++++++++++ include/linux/virtio.h | 1 + 2 files changed, 22 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index cfb028ca238e..5b7df7c455f0 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c@@ -2397,6 +2397,27 @@ void virtio_break_device(struct virtio_device *dev) } EXPORT_SYMBOL_GPL(virtio_break_device); +/* + * This should allow the device to be used by the driver. You may + * need to grab appropriate locks to flush. This should only be used + * in some specific case e.g (probing and restoring). Driver should + * not call this directly. + */ +void __virtio_unbreak_device(struct virtio_device *dev) +{ + struct virtqueue *_vq; + + spin_lock(&dev->vqs_list_lock); + list_for_each_entry(_vq, &dev->vqs, list) { + struct vring_virtqueue *vq = to_vvq(_vq); + + /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ + WRITE_ONCE(vq->broken, false); + } + spin_unlock(&dev->vqs_list_lock); +} +EXPORT_SYMBOL_GPL(__virtio_unbreak_device); + dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 5464f398912a..d8fdf170637c 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h@@ -131,6 +131,7 @@ void unregister_virtio_device(struct virtio_device *dev); bool is_virtio_device(struct device *dev); void virtio_break_device(struct virtio_device *dev); +void __virtio_unbreak_device(struct virtio_device *dev); void virtio_config_changed(struct virtio_device *dev); #ifdef CONFIG_PM_SLEEP
--
2.25.1
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