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=-14.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 D7AEBC433E9 for ; Thu, 3 Sep 2020 19:55:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B87A820716 for ; Thu, 3 Sep 2020 19:55:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Kab0dNHX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729167AbgICTzY (ORCPT ); Thu, 3 Sep 2020 15:55:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:25254 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728312AbgICTzX (ORCPT ); Thu, 3 Sep 2020 15:55:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599162921; 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=hkD8HfSlaP2Xxtnq/zUyNSli/Rr08ovCTsAkBQvzE9w=; b=Kab0dNHX8396uEfTc9UjQJOSRq1SW376hVbkP7vA4Kvdz5NUP6upwg2RRoaq8vJU/i9JvA hqxRxHTgzNn8jg1f80iPIeuet3RYYSnfIMK6w20V7KtrspXhSvpFG/BLX291wAx/v1DMys cSRR29ZLiR7w5tUDuB5uwsNSz0HlPeo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-468-cf-sKM-xP-Wn54caHK8VEQ-1; Thu, 03 Sep 2020 15:55:17 -0400 X-MC-Unique: cf-sKM-xP-Wn54caHK8VEQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 559168010C7; Thu, 3 Sep 2020 19:55:16 +0000 (UTC) Received: from [10.36.112.51] (ovpn-112-51.ams2.redhat.com [10.36.112.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BA4781A4D6; Thu, 3 Sep 2020 19:55:07 +0000 (UTC) Subject: Re: [PATCH v4 06/10] vfio/fsl-mc: Added lock support in preparation for interrupt handling To: Diana Craciun , alex.williamson@redhat.com, kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, bharatb.linux@gmail.com, laurentiu.tudor@nxp.com References: <20200826093315.5279-1-diana.craciun@oss.nxp.com> <20200826093315.5279-7-diana.craciun@oss.nxp.com> From: Auger Eric Message-ID: <6b847d37-ecad-83ab-ae98-96cdd8123591@redhat.com> Date: Thu, 3 Sep 2020 21:55:06 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200826093315.5279-7-diana.craciun@oss.nxp.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Diana On 8/26/20 11:33 AM, Diana Craciun wrote: > Only the DPRC object allocates interrupts from the MSI > interrupt domain. The interrupts are managed by the DPRC in > a pool of interrupts. The access to this pool of interrupts > has to be protected with a lock. > This patch extends the current lock implementation to have a > lock per DPRC. > > Signed-off-by: Diana Craciun > --- > drivers/vfio/fsl-mc/vfio_fsl_mc.c | 91 +++++++++++++++++++++-- > drivers/vfio/fsl-mc/vfio_fsl_mc_private.h | 8 +- > 2 files changed, 91 insertions(+), 8 deletions(-) > > diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c > index 64d5c1fff51f..bbd3365e877e 100644 > --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c > +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c > @@ -17,6 +17,77 @@ > > static struct fsl_mc_driver vfio_fsl_mc_driver; > > +static DEFINE_MUTEX(reflck_lock); > + > +static void vfio_fsl_mc_reflck_get(struct vfio_fsl_mc_reflck *reflck) > +{ > + kref_get(&reflck->kref); > +} > + > +static void vfio_fsl_mc_reflck_release(struct kref *kref) > +{ > + struct vfio_fsl_mc_reflck *reflck = container_of(kref, > + struct vfio_fsl_mc_reflck, > + kref); > + > + mutex_destroy(&reflck->lock); > + kfree(reflck); > + mutex_unlock(&reflck_lock); > +} > + > +static void vfio_fsl_mc_reflck_put(struct vfio_fsl_mc_reflck *reflck) > +{ > + kref_put_mutex(&reflck->kref, vfio_fsl_mc_reflck_release, &reflck_lock); > +} > + > +static struct vfio_fsl_mc_reflck *vfio_fsl_mc_reflck_alloc(void) > +{ > + struct vfio_fsl_mc_reflck *reflck; > + > + reflck = kzalloc(sizeof(*reflck), GFP_KERNEL); > + if (!reflck) > + return ERR_PTR(-ENOMEM); > + > + kref_init(&reflck->kref); > + mutex_init(&reflck->lock); > + > + return reflck; > +} > + > +static int vfio_fsl_mc_reflck_attach(struct vfio_fsl_mc_device *vdev) > +{ > + int ret = 0; > + > + mutex_lock(&reflck_lock); > + if (is_fsl_mc_bus_dprc(vdev->mc_dev)) { > + vdev->reflck = vfio_fsl_mc_reflck_alloc(); this can fail and if this happens I guess you shouldn't return 0. > + } else { > + struct device *mc_cont_dev = vdev->mc_dev->dev.parent; > + struct vfio_device *device; > + struct vfio_fsl_mc_device *cont_vdev; > + > + device = vfio_device_get_from_dev(mc_cont_dev); > + if (!device) { > + ret = -ENODEV; > + goto unlock; > + } > + > + cont_vdev = vfio_device_data(device); are we sure cont_mdev always is != NULL? > + if (!cont_vdev->reflck) { > + vfio_device_put(device); > + ret = -ENODEV; > + goto unlock; > + } > + vfio_fsl_mc_reflck_get(cont_vdev->reflck); > + vdev->reflck = cont_vdev->reflck; > + vfio_device_put(device); > + } > + > +unlock: > + mutex_unlock(&reflck_lock); > + return ret; > +} > + > static int vfio_fsl_mc_regions_init(struct vfio_fsl_mc_device *vdev) > { > struct fsl_mc_device *mc_dev = vdev->mc_dev; > @@ -55,7 +126,7 @@ static int vfio_fsl_mc_open(void *device_data) > if (!try_module_get(THIS_MODULE)) > return -ENODEV; > > - mutex_lock(&vdev->driver_lock); > + mutex_lock(&vdev->reflck->lock); > if (!vdev->refcnt) { > ret = vfio_fsl_mc_regions_init(vdev); > if (ret) > @@ -63,12 +134,12 @@ static int vfio_fsl_mc_open(void *device_data) > } > vdev->refcnt++; > > - mutex_unlock(&vdev->driver_lock); > + mutex_unlock(&vdev->reflck->lock); > > return 0; > > err_reg_init: > - mutex_unlock(&vdev->driver_lock); > + mutex_unlock(&vdev->reflck->lock); > module_put(THIS_MODULE); > return ret; > } > @@ -77,12 +148,12 @@ static void vfio_fsl_mc_release(void *device_data) > { > struct vfio_fsl_mc_device *vdev = device_data; > > - mutex_lock(&vdev->driver_lock); > + mutex_lock(&vdev->reflck->lock); > > if (!(--vdev->refcnt)) > vfio_fsl_mc_regions_cleanup(vdev); > > - mutex_unlock(&vdev->driver_lock); > + mutex_unlock(&vdev->reflck->lock); > > module_put(THIS_MODULE); > } > @@ -329,12 +400,18 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev) > return ret; > } > > + ret = vfio_fsl_mc_reflck_attach(vdev); > + if (ret) { > + vfio_iommu_group_put(group, dev); > + return ret; > + } > + > ret = vfio_fsl_mc_init_device(vdev); > if (ret < 0) { > + vfio_fsl_mc_reflck_put(vdev->reflck); > vfio_iommu_group_put(group, dev); > return ret; > } > - mutex_init(&vdev->driver_lock); > > return ret; > } > @@ -358,7 +435,7 @@ static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev) > > mc_dev->mc_io = NULL; > > - mutex_destroy(&vdev->driver_lock); > + vfio_fsl_mc_reflck_put(vdev->reflck); > > vfio_iommu_group_put(mc_dev->dev.iommu_group, dev); > > diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h > index 818dfd3df4db..3b85d930e060 100644 > --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h > +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h > @@ -15,6 +15,11 @@ > #define VFIO_FSL_MC_INDEX_TO_OFFSET(index) \ > ((u64)(index) << VFIO_FSL_MC_OFFSET_SHIFT) > > +struct vfio_fsl_mc_reflck { > + struct kref kref; > + struct mutex lock; > +}; > + > struct vfio_fsl_mc_region { > u32 flags; > u32 type; > @@ -28,7 +33,8 @@ struct vfio_fsl_mc_device { > int refcnt; > u32 num_regions; > struct vfio_fsl_mc_region *regions; > - struct mutex driver_lock; > + struct vfio_fsl_mc_reflck *reflck; > + > }; > > #endif /* VFIO_FSL_MC_PRIVATE_H */ > Thanks Eric