From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24B13C433EF for ; Wed, 18 May 2022 09:32:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234270AbiERJcp (ORCPT ); Wed, 18 May 2022 05:32:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234248AbiERJcn (ORCPT ); Wed, 18 May 2022 05:32:43 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CA607A5AA9 for ; Wed, 18 May 2022 02:32:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652866360; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7J31Q2VN0OgQuZCLhh0JlKV/aqwl61ASdmry7dAHvIs=; b=Go9tbbKhpfpfrpUJXASw/XFOF8Ugm5VBnzNnL2/dR7S9IL4adAgF+lUmoe3/+v4hPVfMBr /lmSGURAqwE4jJZxwYhe+PT9hXAk4012cSsrh6jwsQlhZbnIoulH95fAAYVsQ+dTGC6JPJ UGDEMny8qBdpSUKk5mrvzadIyEL2GwQ= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-480-SjHa4HwlNGmAnBzPSKmHsA-1; Wed, 18 May 2022 05:32:36 -0400 X-MC-Unique: SjHa4HwlNGmAnBzPSKmHsA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id F0D2829DD9AA; Wed, 18 May 2022 09:32:35 +0000 (UTC) Received: from localhost (dhcp-192-194.str.redhat.com [10.33.192.194]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AD6101410DD5; Wed, 18 May 2022 09:32:35 +0000 (UTC) From: Cornelia Huck To: Jason Wang , mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: Re: [PATCH V5 6/9] virtio-ccw: implement synchronize_cbs() In-Reply-To: <20220518035951.94220-7-jasowang@redhat.com> Organization: Red Hat GmbH References: <20220518035951.94220-1-jasowang@redhat.com> <20220518035951.94220-7-jasowang@redhat.com> User-Agent: Notmuch/0.34 (https://notmuchmail.org) Date: Wed, 18 May 2022 11:32:33 +0200 Message-ID: <87tu9nfaoe.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 18 2022, Jason Wang 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/ > > Cc: Thomas Gleixner > Cc: Peter Zijlstra > Cc: "Paul E. McKenney" > Cc: Marc Zyngier > Cc: Halil Pasic > Cc: Cornelia Huck > Cc: Vineeth Vijayan > Cc: Peter Oberparleiter > Cc: linux-s390@vger.kernel.org > Signed-off-by: Jason Wang > --- > 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. */ > + */ > + 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. */ > + */ > + 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. > + 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. */