Messages in this thread | | | From | Jason Wang <> | Date | Thu, 19 May 2022 16:02:30 +0800 | Subject | Re: [PATCH V5 6/9] virtio-ccw: implement synchronize_cbs() |
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On Wed, May 18, 2022 at 5:32 PM Cornelia Huck <cohuck@redhat.com> wrote: > > On Wed, May 18 2022, Jason Wang <jasowang@redhat.com> wrote: > > > 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 ans used in the synchronization method. > > s/ans/and/ >
Will fix.
> > > > 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 > > Signed-off-by: Jason Wang <jasowang@redhat.com> > > --- > > drivers/s390/virtio/virtio_ccw.c | 27 +++++++++++++++++++++++++++ > > 1 file changed, 27 insertions(+) > > > > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > > index d35e7a3f7067..22d36594bcdd 100644 > > --- a/drivers/s390/virtio/virtio_ccw.c > > +++ b/drivers/s390/virtio/virtio_ccw.c > > @@ -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 +985,27 @@ 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) { > > + /* > > + * Synchronize with the vring_interrupt() with airq indicator > > Maybe > > /* > * This device uses adapter interrupts: synchronize with > * vring_interrupt() called by virtio_airq_handler() via the indicator > * area lock. > */ >
Fine.
> > + */ > > + write_lock_irq(&info->lock); > > + write_unlock_irq(&info->lock); > > + } else { > > + /* > > + * Synchronize with the vring_interrupt() called by > > + * virtio_ccw_int_handler(). > > /* > * This device uses classic interrupts: synchronize with > * vring_interrupt() called by virtio_ccw_int_handler() via the > * per-device irq_lock. > */ >
Looks fine.
> > + */ > > + 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 +1017,7 @@ 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 +1129,8 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev, > > vcdev->err = -EIO; > > } > > virtio_ccw_check_activity(vcdev, activity); > > + /* Local interrupt should be disabled at this time */ > > /* Interrupts are disabled here. */ > > ? > > Interrupts enabled here would surely be a bug.
Right.
Thanks
> > > + 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. */ >
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