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 6D577C433EF for ; Fri, 27 May 2022 06:02:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236463AbiE0GCr (ORCPT ); Fri, 27 May 2022 02:02:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240083AbiE0GCe (ORCPT ); Fri, 27 May 2022 02:02:34 -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 D30F82BE0 for ; Thu, 26 May 2022 23:02:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631349; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=txm7DjcKuANfsEZ3GBtdkhzXAQmx0UitZyi9sP1Io7U=; b=V3dRNeiDSs4JIDa4nggnIWH3cwANct2Bd2zf8zLdQ7fzl8AHkqkVewN8RXwJMWgm0hye3Q GBad+LRmZUKDEtvx1tPwFSiakenQWasXL53CtbnWg/+GQUZZ79R6a3LIWkN+DE93AVv8mw WqgKexiVJc5v9aqvkJ/kn79vnb7Dv+Y= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-546-7bDIP2W9Nq-RFigjdhVmww-1; Fri, 27 May 2022 02:02:26 -0400 X-MC-Unique: 7bDIP2W9Nq-RFigjdhVmww-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CA90E858F0C; Fri, 27 May 2022 06:02:25 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 138CF2166B2F; Fri, 27 May 2022 06:02:18 +0000 (UTC) From: Jason Wang To: 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, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 6/9] virtio-ccw: implement synchronize_cbs() Date: Fri, 27 May 2022 14:01:17 +0800 Message-Id: <20220527060120.20964-7-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org 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 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 Reviewed-by: Halil Pasic Signed-off-by: Jason Wang --- drivers/s390/virtio/virtio_ccw.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index d35e7a3f7067..c188e4f20ca3 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 +985,30 @@ 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); -- 2.25.1