From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:60400 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726650AbfHMLaM (ORCPT ); Tue, 13 Aug 2019 07:30:12 -0400 Date: Tue, 13 Aug 2019 13:29:57 +0200 From: Cornelia Huck Subject: Re: [PATCH] s390: vfio-ap: remove unnecessary calls to disable queue interrupts Message-ID: <20190813132957.7fafad2d.cohuck@redhat.com> In-Reply-To: <1565642829-20157-1-git-send-email-akrowiak@linux.ibm.com> References: <1565642829-20157-1-git-send-email-akrowiak@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Tony Krowiak Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@linux.ibm.com, borntraeger@de.ibm.com, frankja@linux.ibm.com, david@redhat.com, mjrosato@linux.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, pmorel@linux.ibm.com, pasic@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com On Mon, 12 Aug 2019 16:47:09 -0400 Tony Krowiak wrote: > When an AP queue is reset (zeroized), interrupts are disabled. The queue > reset function currently tries to disable interrupts unnecessarily. This patch > removes the unnecessary calls to disable interrupts after queue reset. > > Signed-off-by: Tony Krowiak > --- > drivers/s390/crypto/vfio_ap_ops.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index 0604b49a4d32..407c2f0f25f9 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -1114,18 +1114,19 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > return NOTIFY_OK; > } > > -static void vfio_ap_irq_disable_apqn(int apqn) > +static struct vfio_ap_queue *vfio_ap_find_qdev(int apqn) > { > struct device *dev; > - struct vfio_ap_queue *q; > + struct vfio_ap_queue *q = NULL; > > dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL, > &apqn, match_apqn); > if (dev) { > q = dev_get_drvdata(dev); > - vfio_ap_irq_disable(q); > put_device(dev); > } > + > + return q; > } > > int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi, > @@ -1164,6 +1165,7 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) > int rc = 0; > unsigned long apid, apqi; > struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); > + struct vfio_ap_queue *q; > > for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, > matrix_mdev->matrix.apm_max + 1) { > @@ -1177,7 +1179,10 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) > */ > if (ret) > rc = ret; > - vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi)); Might be useful to stick a comment in this function that resetting the queue has also disabled the interrupts, as the architecture documentation for that is not publicly available. > + > + q = vfio_ap_find_qdev(AP_MKQID(apid, apqi)); > + if (q) > + vfio_ap_free_aqic_resources(q); > } > } > Trusting your reading of the architecture, Reviewed-by: Cornelia Huck