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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA4D4C43381 for ; Fri, 15 Feb 2019 09:49:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C02D82070D for ; Fri, 15 Feb 2019 09:49:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393456AbfBOJtO (ORCPT ); Fri, 15 Feb 2019 04:49:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46264 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388842AbfBOJtN (ORCPT ); Fri, 15 Feb 2019 04:49:13 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C76BDC01DE13; Fri, 15 Feb 2019 09:49:12 +0000 (UTC) Received: from gondolin (dhcp-192-213.str.redhat.com [10.33.192.213]) by smtp.corp.redhat.com (Postfix) with ESMTP id 34C50600C1; Fri, 15 Feb 2019 09:49:06 +0000 (UTC) Date: Fri, 15 Feb 2019 10:49:04 +0100 From: Cornelia Huck To: Pierre Morel Cc: borntraeger@de.ibm.com, alex.williamson@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, akrowiak@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com Subject: Re: [PATCH v3 4/9] s390: ap: tools to find a queue with a specific APQN Message-ID: <20190215104904.5cbe31bb.cohuck@redhat.com> In-Reply-To: <1550152269-6317-5-git-send-email-pmorel@linux.ibm.com> References: <1550152269-6317-1-git-send-email-pmorel@linux.ibm.com> <1550152269-6317-5-git-send-email-pmorel@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 15 Feb 2019 09:49:12 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 14 Feb 2019 14:51:04 +0100 Pierre Morel wrote: > We need to find the queue with a specific APQN during the > handling of the interception of the PQAP/AQIC instruction. > > To handle the AP associated device reference count we keep > track of it in the vfio_ap_queue until we put the device. So, the relationship is (struct ap_device)--(driver_data)-->(struct vfio_ap_queue)--(pointer)-->(struct ap_device) ? IOW, a backlink? If so, can't you already set that up during probe? Or am I confused by the various similar devices again? Maybe a diagram would help... > > Signed-off-by: Pierre Morel > --- > drivers/s390/crypto/vfio_ap_ops.c | 54 +++++++++++++++++++++++++++++++++++ > drivers/s390/crypto/vfio_ap_private.h | 1 + > 2 files changed, 55 insertions(+) > > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index 900b9cf..2a52c9b 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -24,6 +24,60 @@ > #define VFIO_AP_MDEV_TYPE_HWVIRT "passthrough" > #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device" > > +/** > + * vfio_ap_check_apqn: check if a ap_queue is of a given APQN > + * > + * Returns 1 if we have a match. > + * Otherwise returns 0. > + */ > +static int vfio_ap_check_apqn(struct device *dev, void *data) > +{ > + struct vfio_ap_queue *q = dev_get_drvdata(dev); > + > + return (q->apqn == *(int *)data); > +} > + > +/** > + * vfio_ap_get_queue: Retrieve a queue with a specific APQN > + * @apqn: The queue APQN > + * > + * Retrieve a queue with a specific APQN from the list of the > + * devices associated to the vfio_ap_driver. > + * > + * The vfio_ap_queue has been already associated with the device > + * during the probe. > + * Store the associated device for reference counting > + * > + * Returns the pointer to the associated vfio_ap_queue > + */ > +static __attribute__((unused)) Eww. Can you get rid of that by reordering or squashing patches? > + struct vfio_ap_queue *vfio_ap_get_queue(int apqn) > +{ > + struct device *dev; > + struct vfio_ap_queue *q; > + > + dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL, &apqn, > + vfio_ap_check_apqn); > + if (!dev) > + return NULL; > + q = dev_get_drvdata(dev); > + q->dev = dev; > + return q; > +} > + > +/** > + * vfio_ap_put_queue: lower device reference count for a queue > + * @q: The queue > + * > + * put the associated device > + * > + */ > +static __attribute__((unused)) void vfio_ap_put_queue(struct vfio_ap_queue *q) > +{ > + put_device(q->dev); > + q->dev = NULL; > +} > + > static void vfio_ap_matrix_init(struct ap_config_info *info, > struct ap_matrix *matrix) > { > diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h > index 8836f01..081f0d7 100644 > --- a/drivers/s390/crypto/vfio_ap_private.h > +++ b/drivers/s390/crypto/vfio_ap_private.h > @@ -87,6 +87,7 @@ extern int vfio_ap_mdev_register(void); > extern void vfio_ap_mdev_unregister(void); > > struct vfio_ap_queue { > + struct device *dev; > int apqn; > }; > #endif /* _VFIO_AP_PRIVATE_H_ */