From nobody Thu Feb 12 09:32:40 2026 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 6CF76EED61D for ; Fri, 15 Sep 2023 16:59:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234756AbjIOQ6m (ORCPT ); Fri, 15 Sep 2023 12:58:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234435AbjIOQ63 (ORCPT ); Fri, 15 Sep 2023 12:58:29 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 91805211E for ; Fri, 15 Sep 2023 09:58:23 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7A023C15; Fri, 15 Sep 2023 09:59:00 -0700 (PDT) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2912D3F5A1; Fri, 15 Sep 2023 09:58:22 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, jgg@nvidia.com, baolu.lu@linux.intel.com Subject: [PATCH v3 1/7] iommu: Factor out some helpers Date: Fri, 15 Sep 2023 17:58:05 +0100 Message-Id: X-Mailer: git-send-email 2.39.2.101.g768bb238c484.dirty In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The pattern for picking the first device out of the group list is repeated a few times now, so it's clearly worth factoring out, which also helps hide the iommu_group_dev detail from places that don't need to know. Similarly, the safety check for dev_iommu_ops() at certain public interfaces starts looking a bit repetitive, and might not be completely obvious at first glance, so let's factor that out for clarity as well, in preparation for more uses of both. Reviewed-by: Lu Baolu Signed-off-by: Robin Murphy --- v3: Rename dev_iommu_ops_valid() to reflect what it's actually checking, rather than an implied consequence. --- drivers/iommu/iommu.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3bfc56df4f78..4566d0001cd3 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -363,6 +363,15 @@ static void dev_iommu_free(struct device *dev) kfree(param); } =20 +/* + * Internal equivalent of device_iommu_mapped() for when we care that a de= vice + * actually has API ops, and don't want false positives from VFIO-only gro= ups. + */ +static bool dev_has_iommu(struct device *dev) +{ + return dev->iommu && dev->iommu->iommu_dev; +} + static u32 dev_iommu_get_max_pasids(struct device *dev) { u32 max_pasids =3D 0, bits =3D 0; @@ -614,7 +623,7 @@ static void __iommu_group_remove_device(struct device *= dev) =20 list_del(&device->list); __iommu_group_free_device(group, device); - if (dev->iommu && dev->iommu->iommu_dev) + if (dev_has_iommu(dev)) iommu_deinit_device(dev); else dev->iommu_group =3D NULL; @@ -1218,6 +1227,12 @@ void iommu_group_remove_device(struct device *dev) } EXPORT_SYMBOL_GPL(iommu_group_remove_device); =20 +static struct device *iommu_group_first_dev(struct iommu_group *group) +{ + lockdep_assert_held(&group->mutex); + return list_first_entry(&group->devices, struct group_device, list)->dev; +} + /** * iommu_group_for_each_dev - iterate over each device in the group * @group: the group @@ -1745,9 +1760,7 @@ __iommu_group_alloc_default_domain(const struct bus_t= ype *bus, static struct iommu_domain * iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) { - const struct bus_type *bus =3D - list_first_entry(&group->devices, struct group_device, list) - ->dev->bus; + const struct bus_type *bus =3D iommu_group_first_dev(group)->bus; struct iommu_domain *dom; =20 lockdep_assert_held(&group->mutex); @@ -1912,7 +1925,7 @@ bool device_iommu_capable(struct device *dev, enum io= mmu_cap cap) { const struct iommu_ops *ops; =20 - if (!dev->iommu || !dev->iommu->iommu_dev) + if (!dev_has_iommu(dev)) return false; =20 ops =3D dev_iommu_ops(dev); @@ -2903,8 +2916,8 @@ EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); */ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f= eat) { - if (dev->iommu && dev->iommu->iommu_dev) { - const struct iommu_ops *ops =3D dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops =3D dev_iommu_ops(dev); =20 if (ops->dev_enable_feat) return ops->dev_enable_feat(dev, feat); @@ -2919,8 +2932,8 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); */ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features = feat) { - if (dev->iommu && dev->iommu->iommu_dev) { - const struct iommu_ops *ops =3D dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops =3D dev_iommu_ops(dev); =20 if (ops->dev_disable_feat) return ops->dev_disable_feat(dev, feat); @@ -3190,21 +3203,18 @@ void iommu_device_unuse_default_domain(struct devic= e *dev) =20 static int __iommu_group_alloc_blocking_domain(struct iommu_group *group) { - struct group_device *dev =3D - list_first_entry(&group->devices, struct group_device, list); + struct device *dev =3D iommu_group_first_dev(group); =20 if (group->blocking_domain) return 0; =20 - group->blocking_domain =3D - __iommu_domain_alloc(dev->dev->bus, IOMMU_DOMAIN_BLOCKED); + group->blocking_domain =3D __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_BL= OCKED); if (!group->blocking_domain) { /* * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED * create an empty domain instead. */ - group->blocking_domain =3D __iommu_domain_alloc( - dev->dev->bus, IOMMU_DOMAIN_UNMANAGED); + group->blocking_domain =3D __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_U= NMANAGED); if (!group->blocking_domain) return -EINVAL; } --=20 2.39.2.101.g768bb238c484.dirty