From nobody Fri Jan 2 11:54:22 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 1B7C2CDB473 for ; Wed, 11 Oct 2023 18:15:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233280AbjJKSPG (ORCPT ); Wed, 11 Oct 2023 14:15:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233183AbjJKSPD (ORCPT ); Wed, 11 Oct 2023 14:15:03 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4D09293 for ; Wed, 11 Oct 2023 11:15:02 -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 CD1C6150C; Wed, 11 Oct 2023 11:15:42 -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 39B5B3F5A1; Wed, 11 Oct 2023 11:15:01 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v5 1/7] iommu: Factor out some helpers Date: Wed, 11 Oct 2023 19:14:48 +0100 Message-Id: <72c599ef84ac29c9759c7f0ecc7bd69fa9aaf5c1.1697047261.git.robin.murphy@arm.com> 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 Reviewed-by: Jason Gunthorpe Reviewed-by: Jerry Snitselaar --- v3: Rename dev_iommu_ops_valid() to reflect what it's actually checking, rather than an implied consequence. v4: Rebase, also catch the sneaky one in iommu_get_group_resv_regions() which wasn't the full pattern (but really should be since it guards the dev_iommu_ops() invocation in iommu_get_resv_regions()). --- drivers/iommu/iommu.c | 56 ++++++++++++++++++++----------------------- 1 file changed, 26 insertions(+), 30 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index f9f315d58a3a..5a3ce293a5de 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -368,6 +368,15 @@ 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; @@ -620,7 +629,7 @@ 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; @@ -819,7 +828,7 @@ int iommu_get_group_resv_regions(struct iommu_group *gr= oup, * Non-API groups still expose reserved_regions in sysfs, * so filter out calls that get here that way. */ - if (!device->dev->iommu) + if (!dev_has_iommu(device->dev)) break; =20 INIT_LIST_HEAD(&dev_resv_regions); @@ -1224,6 +1233,12 @@ 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 @@ -1751,23 +1766,6 @@ __iommu_group_alloc_default_domain(struct iommu_grou= p *group, int req_type) return __iommu_group_domain_alloc(group, req_type); } =20 -/* - * Returns the iommu_ops for the devices in an iommu group. - * - * It is assumed that all devices in an iommu group are managed by a single - * IOMMU unit. Therefore, this returns the dev_iommu_ops of the first devi= ce - * in the group. - */ -static const struct iommu_ops *group_iommu_ops(struct iommu_group *group) -{ - struct group_device *device =3D - list_first_entry(&group->devices, struct group_device, list); - - lockdep_assert_held(&group->mutex); - - return dev_iommu_ops(device->dev); -} - /* * req_type of 0 means "auto" which means to select a domain based on * iommu_def_domain_type or what the driver actually supports. @@ -1775,7 +1773,7 @@ static const struct iommu_ops *group_iommu_ops(struct= iommu_group *group) static struct iommu_domain * iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) { - const struct iommu_ops *ops =3D group_iommu_ops(group); + const struct iommu_ops *ops =3D dev_iommu_ops(iommu_group_first_dev(group= )); struct iommu_domain *dom; =20 lockdep_assert_held(&group->mutex); @@ -1853,7 +1851,7 @@ static int iommu_bus_notifier(struct notifier_block *= nb, static int iommu_get_def_domain_type(struct iommu_group *group, struct device *dev, int cur_type) { - const struct iommu_ops *ops =3D group_iommu_ops(group); + const struct iommu_ops *ops =3D dev_iommu_ops(dev); int type; =20 if (!ops->def_domain_type) @@ -2020,7 +2018,7 @@ 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); @@ -2117,11 +2115,9 @@ static struct iommu_domain *__iommu_domain_alloc(con= st struct iommu_ops *ops, static struct iommu_domain * __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type) { - struct device *dev =3D - list_first_entry(&group->devices, struct group_device, list) - ->dev; + struct device *dev =3D iommu_group_first_dev(group); =20 - return __iommu_domain_alloc(group_iommu_ops(group), dev, type); + return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type); } =20 struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) @@ -2972,8 +2968,8 @@ 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); @@ -2988,8 +2984,8 @@ 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); --=20 2.39.2.101.g768bb238c484.dirty From nobody Fri Jan 2 11:54:22 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 DC153CDB474 for ; Wed, 11 Oct 2023 18:15:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234947AbjJKSPO (ORCPT ); Wed, 11 Oct 2023 14:15:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233215AbjJKSPF (ORCPT ); Wed, 11 Oct 2023 14:15:05 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2544193 for ; Wed, 11 Oct 2023 11:15:04 -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 A58CD14BF; Wed, 11 Oct 2023 11:15:44 -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 129F93F5A1; Wed, 11 Oct 2023 11:15:02 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v5 2/7] iommu: Decouple iommu_present() from bus ops Date: Wed, 11 Oct 2023 19:14:49 +0100 Message-Id: <6711338e24dd1edfd02187f25cf40d8622cefdb2.1697047261.git.robin.murphy@arm.com> 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" Much as I'd like to remove iommu_present(), the final remaining users are proving stubbornly difficult to clean up, so kick that can down the road and just rework it to preserve the current behaviour without depending on bus ops. Since commit 57365a04c921 ("iommu: Move bus setup to IOMMU device registration"), any registered IOMMU instance is already considered "present" for every entry in iommu_buses, so it's simply a case of validating the bus and checking we have at least once IOMMU. Reviewed-by: Jason Gunthorpe Signed-off-by: Robin Murphy Reviewed-by: Jerry Snitselaar Reviewed-by: Lu Baolu --- v3: Tweak to use the ops-based check rather than group-based, to properly match the existing behaviour v4: Just look for IOMMU instances instead of managed devices --- drivers/iommu/iommu.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 5a3ce293a5de..7bb92e8b7a49 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2000,9 +2000,28 @@ int bus_iommu_probe(const struct bus_type *bus) return 0; } =20 +/** + * iommu_present() - make platform-specific assumptions about an IOMMU + * @bus: bus to check + * + * Do not use this function. You want device_iommu_mapped() instead. + * + * Return: true if some IOMMU is present and aware of devices on the given= bus; + * in general it may not be the only IOMMU, and it may not have anything t= o do + * with whatever device you are ultimately interested in. + */ bool iommu_present(const struct bus_type *bus) { - return bus->iommu_ops !=3D NULL; + bool ret =3D false; + + for (int i =3D 0; i < ARRAY_SIZE(iommu_buses); i++) { + if (iommu_buses[i] =3D=3D bus) { + spin_lock(&iommu_device_lock); + ret =3D !list_empty(&iommu_device_list); + spin_unlock(&iommu_device_lock); + } + } + return ret; } EXPORT_SYMBOL_GPL(iommu_present); =20 --=20 2.39.2.101.g768bb238c484.dirty From nobody Fri Jan 2 11:54:22 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 10D8DCDB473 for ; Wed, 11 Oct 2023 18:15:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235127AbjJKSPU (ORCPT ); Wed, 11 Oct 2023 14:15:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233335AbjJKSPH (ORCPT ); Wed, 11 Oct 2023 14:15:07 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BCB489D for ; Wed, 11 Oct 2023 11:15:05 -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 43AB01516; Wed, 11 Oct 2023 11:15:46 -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 A50F23F5A1; Wed, 11 Oct 2023 11:15:04 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v5 3/7] iommu: Validate that devices match domains Date: Wed, 11 Oct 2023 19:14:50 +0100 Message-Id: <4e8bda33aac4021b444e40389648deccf61c1f37.1697047261.git.robin.murphy@arm.com> 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" Before we can allow drivers to coexist, we need to make sure that one driver's domain ops can't misinterpret another driver's dev_iommu_priv data. To that end, add a token to the domain so we can remember how it was allocated - for now this may as well be the device ops, since they still correlate 1:1 with drivers. We can trust ourselves for internal default domain attachment, so add checks to cover all the public attach interfaces. Reviewed-by: Lu Baolu Reviewed-by: Jason Gunthorpe Signed-off-by: Robin Murphy Reviewed-by: Jerry Snitselaar --- v4: Cover iommu_attach_device_pasid() as well, and improve robustness against theoretical attempts to attach a noiommu group. --- drivers/iommu/iommu.c | 10 ++++++++++ include/linux/iommu.h | 1 + 2 files changed, 11 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 7bb92e8b7a49..578292d3b152 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2114,6 +2114,7 @@ static struct iommu_domain *__iommu_domain_alloc(cons= t struct iommu_ops *ops, return NULL; =20 domain->type =3D type; + domain->owner =3D ops; /* * If not already set, assume all sizes by default; the driver * may override this later @@ -2279,10 +2280,16 @@ struct iommu_domain *iommu_get_dma_domain(struct de= vice *dev) static int __iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) { + struct device *dev; + if (group->domain && group->domain !=3D group->default_domain && group->domain !=3D group->blocking_domain) return -EBUSY; =20 + dev =3D iommu_group_first_dev(group); + if (!dev_has_iommu(dev) || dev_iommu_ops(dev) !=3D domain->owner) + return -EINVAL; + return __iommu_group_set_domain(group, domain); } =20 @@ -3480,6 +3487,9 @@ int iommu_attach_device_pasid(struct iommu_domain *do= main, if (!group) return -ENODEV; =20 + if (!dev_has_iommu(dev) || dev_iommu_ops(dev) !=3D domain->owner) + return -EINVAL; + mutex_lock(&group->mutex); curr =3D xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL); if (curr) { diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 2d2802fb2c74..5c9560813d05 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -99,6 +99,7 @@ struct iommu_domain_geometry { struct iommu_domain { unsigned type; const struct iommu_domain_ops *ops; + const struct iommu_ops *owner; /* Whose domain_alloc we came from */ unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */ struct iommu_domain_geometry geometry; struct iommu_dma_cookie *iova_cookie; --=20 2.39.2.101.g768bb238c484.dirty From nobody Fri Jan 2 11:54:22 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 6055ACDB473 for ; Wed, 11 Oct 2023 18:15:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235017AbjJKSPR (ORCPT ); Wed, 11 Oct 2023 14:15:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233342AbjJKSPI (ORCPT ); Wed, 11 Oct 2023 14:15:08 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C69BC9E for ; Wed, 11 Oct 2023 11:15:06 -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 545E8150C; Wed, 11 Oct 2023 11:15:47 -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 B5E143F5A1; Wed, 11 Oct 2023 11:15:05 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v5 4/7] iommu: Decouple iommu_domain_alloc() from bus ops Date: Wed, 11 Oct 2023 19:14:51 +0100 Message-Id: <81a0a66d76b3826f1a0b55d7fbaf0986034c7abc.1697047261.git.robin.murphy@arm.com> 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" As the final remaining piece of bus-dependent API, iommu_domain_alloc() can now take responsibility for the "one iommu_ops per bus" rule for itself. It turns out we can't safely make the internal allocation call any more group-based or device-based yet - that will have to wait until the external callers can pass the right thing - but we can at least get as far as deriving "bus ops" based on which driver is actually managing devices on the given bus, rather than whichever driver won the race to register first. This will then leave us able to convert the last of the core internals over to the IOMMU-instance model, allow multiple drivers to register and actually coexist (modulo the above limitation for unmanaged domain users in the short term), and start trying to solve the long-standing iommu_probe_device() mess. Signed-off-by: Robin Murphy Reviewed-by: Jason Gunthorpe Reviewed-by: Jerry Snitselaar --- v5: Rewrite, de-scoping to just retrieve ops under the same assumptions as the existing code. --- drivers/iommu/iommu.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 578292d3b152..18667dc2ff86 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2140,12 +2140,31 @@ __iommu_group_domain_alloc(struct iommu_group *grou= p, unsigned int type) return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type); } =20 +static int __iommu_domain_alloc_dev(struct device *dev, void *data) +{ + const struct iommu_ops **ops =3D data; + + if (!dev_has_iommu(dev)) + return 0; + + if (WARN_ONCE(*ops && *ops !=3D dev_iommu_ops(dev), + "Multiple IOMMU drivers present for bus %s, which the public IOMMU= API can't fully support yet. You will still need to disable one or more fo= r this to work, sorry!\n", + dev_bus_name(dev))) + return -EBUSY; + + *ops =3D dev_iommu_ops(dev); + return 0; +} + struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) { - if (bus =3D=3D NULL || bus->iommu_ops =3D=3D NULL) + const struct iommu_ops *ops =3D NULL; + int err =3D bus_for_each_dev(bus, NULL, &ops, __iommu_domain_alloc_dev); + + if (err || !ops) return NULL; - return __iommu_domain_alloc(bus->iommu_ops, NULL, - IOMMU_DOMAIN_UNMANAGED); + + return __iommu_domain_alloc(ops, NULL, IOMMU_DOMAIN_UNMANAGED); } EXPORT_SYMBOL_GPL(iommu_domain_alloc); =20 --=20 2.39.2.101.g768bb238c484.dirty From nobody Fri Jan 2 11:54:22 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 5FDCCCDB474 for ; Wed, 11 Oct 2023 18:15:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234771AbjJKSPX (ORCPT ); Wed, 11 Oct 2023 14:15:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233183AbjJKSPM (ORCPT ); Wed, 11 Oct 2023 14:15:12 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C325AC6 for ; Wed, 11 Oct 2023 11:15:08 -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 4ED1D14BF; Wed, 11 Oct 2023 11:15:49 -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 A721E3F5A1; Wed, 11 Oct 2023 11:15:07 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v5 5/7] iommu/arm-smmu: Don't register fwnode for legacy binding Date: Wed, 11 Oct 2023 19:14:52 +0100 Message-Id: <3a5cd62dd21ed58f337bb9a389d301054e503dc3.1697047261.git.robin.murphy@arm.com> 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" When using the legacy binding we bypass the of_xlate mechanism, so avoid registering the instance fwnodes which act as keys for that. This will help __iommu_probe_device() to retrieve the registered ops the same way as for x86 etc. when no fwspec has previously been set up by of_xlate. Reviewed-by: Jason Gunthorpe Signed-off-by: Robin Murphy Acked-by: Will Deacon Reviewed-by: Jerry Snitselaar --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-= smmu/arm-smmu.c index d6d1a2a55cc0..4b83a3adacd6 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -2161,7 +2161,8 @@ static int arm_smmu_device_probe(struct platform_devi= ce *pdev) return err; } =20 - err =3D iommu_device_register(&smmu->iommu, &arm_smmu_ops, dev); + err =3D iommu_device_register(&smmu->iommu, &arm_smmu_ops, + using_legacy_binding ? NULL : dev); if (err) { dev_err(dev, "Failed to register iommu\n"); iommu_device_sysfs_remove(&smmu->iommu); --=20 2.39.2.101.g768bb238c484.dirty From nobody Fri Jan 2 11:54:22 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 2D31FCDB475 for ; Wed, 11 Oct 2023 18:15:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346207AbjJKSP0 (ORCPT ); Wed, 11 Oct 2023 14:15:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235122AbjJKSPN (ORCPT ); Wed, 11 Oct 2023 14:15:13 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E5E1CDD for ; Wed, 11 Oct 2023 11:15:10 -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 70AD0150C; Wed, 11 Oct 2023 11:15:51 -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 83EA23F5A1; Wed, 11 Oct 2023 11:15:09 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org, "Rafael J . Wysocki" , Christoph Hellwig , Greg Kroah-Hartman Subject: [PATCH v5 6/7] iommu: Retire bus ops Date: Wed, 11 Oct 2023 19:14:53 +0100 Message-Id: <2411f20c801140b3cff37193ec2c08393a754997.1697047261.git.robin.murphy@arm.com> 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" With the rest of the API internals converted, it's time to finally tackle probe_device and how we bootstrap the per-device ops association to begin with. This ends up being disappointingly straightforward, since fwspec users are already doing it in order to find their of_xlate callback, and it works out that we can easily do the equivalent for other drivers too. Then shuffle the remaining awareness of iommu_ops into the couple of core headers that still need it, and breathe a sigh of relief. Ding dong the bus ops are gone! CC: Rafael J. Wysocki Acked-by: Christoph Hellwig Acked-by: Greg Kroah-Hartman Reviewed-by: Lu Baolu Reviewed-by: Jason Gunthorpe Signed-off-by: Robin Murphy Reviewed-by: Jerry Snitselaar --- v4: Don't forget new reference in iommu_device_register_bus() --- drivers/iommu/iommu.c | 31 ++++++++++++++++++------------- include/acpi/acpi_bus.h | 2 ++ include/linux/device.h | 1 - include/linux/device/bus.h | 5 ----- include/linux/dma-map-ops.h | 1 + 5 files changed, 21 insertions(+), 19 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 18667dc2ff86..6962f2c99428 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -148,7 +148,7 @@ struct iommu_group_attribute iommu_group_attr_##_name = =3D \ static LIST_HEAD(iommu_device_list); static DEFINE_SPINLOCK(iommu_device_lock); =20 -static struct bus_type * const iommu_buses[] =3D { +static const struct bus_type * const iommu_buses[] =3D { &platform_bus_type, #ifdef CONFIG_PCI &pci_bus_type, @@ -257,13 +257,6 @@ int iommu_device_register(struct iommu_device *iommu, /* We need to be able to take module references appropriately */ if (WARN_ON(is_module_address((unsigned long)ops) && !ops->owner)) return -EINVAL; - /* - * Temporarily enforce global restriction to a single driver. This was - * already the de-facto behaviour, since any possible combination of - * existing drivers would compete for at least the PCI or platform bus. - */ - if (iommu_buses[0]->iommu_ops && iommu_buses[0]->iommu_ops !=3D ops) - return -EBUSY; =20 iommu->ops =3D ops; if (hwdev) @@ -273,10 +266,8 @@ int iommu_device_register(struct iommu_device *iommu, list_add_tail(&iommu->list, &iommu_device_list); spin_unlock(&iommu_device_lock); =20 - for (int i =3D 0; i < ARRAY_SIZE(iommu_buses) && !err; i++) { - iommu_buses[i]->iommu_ops =3D ops; + for (int i =3D 0; i < ARRAY_SIZE(iommu_buses) && !err; i++) err =3D bus_iommu_probe(iommu_buses[i]); - } if (err) iommu_device_unregister(iommu); return err; @@ -329,7 +320,6 @@ int iommu_device_register_bus(struct iommu_device *iomm= u, list_add_tail(&iommu->list, &iommu_device_list); spin_unlock(&iommu_device_lock); =20 - bus->iommu_ops =3D ops; err =3D bus_iommu_probe(bus); if (err) { iommu_device_unregister_bus(iommu, bus, nb); @@ -496,12 +486,27 @@ static void iommu_deinit_device(struct device *dev) =20 static int __iommu_probe_device(struct device *dev, struct list_head *grou= p_list) { - const struct iommu_ops *ops =3D dev->bus->iommu_ops; + const struct iommu_ops *ops; + struct iommu_fwspec *fwspec; struct iommu_group *group; static DEFINE_MUTEX(iommu_probe_device_lock); struct group_device *gdev; int ret; =20 + /* + * For FDT-based systems and ACPI IORT/VIOT, drivers register IOMMU + * instances with non-NULL fwnodes, and client devices should have been + * identified with a fwspec by this point. Otherwise, we can currently + * assume that only one of Intel, AMD, s390, PAMU or legacy SMMUv2 can + * be present, and that any of their registered instances has suitable + * ops for probing, and thus cheekily co-opt the same mechanism. + */ + fwspec =3D dev_iommu_fwspec_get(dev); + if (fwspec && fwspec->ops) + ops =3D fwspec->ops; + else + ops =3D iommu_ops_from_fwnode(NULL); + if (!ops) return -ENODEV; /* diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 254685085c82..13d959b3ba29 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -623,6 +623,8 @@ struct acpi_pci_root { =20 /* helper */ =20 +struct iommu_ops; + bool acpi_dma_supported(const struct acpi_device *adev); enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev); int acpi_iommu_fwspec_init(struct device *dev, u32 id, diff --git a/include/linux/device.h b/include/linux/device.h index 56d93a1ffb7b..b78e66f3b34a 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -42,7 +42,6 @@ struct class; struct subsys_private; struct device_node; struct fwnode_handle; -struct iommu_ops; struct iommu_group; struct dev_pin_info; struct dev_iommu; diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h index ae10c4322754..e25aab08f873 100644 --- a/include/linux/device/bus.h +++ b/include/linux/device/bus.h @@ -62,9 +62,6 @@ struct fwnode_handle; * this bus. * @pm: Power management operations of this bus, callback the specific * device driver's pm-ops. - * @iommu_ops: IOMMU specific operations for this bus, used to attach IOM= MU - * driver implementations to a bus and allow the driver to do - * bus-specific setup * @need_parent_lock: When probing or removing a device on this bus, the * device core should lock the device's parent. * @@ -104,8 +101,6 @@ struct bus_type { =20 const struct dev_pm_ops *pm; =20 - const struct iommu_ops *iommu_ops; - bool need_parent_lock; }; =20 diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index f2fc203fb8a1..a52e508d1869 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -11,6 +11,7 @@ #include =20 struct cma; +struct iommu_ops; =20 /* * Values for struct dma_map_ops.flags: --=20 2.39.2.101.g768bb238c484.dirty From nobody Fri Jan 2 11:54:22 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 B00ADCDB474 for ; Wed, 11 Oct 2023 18:15:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346937AbjJKSP3 (ORCPT ); Wed, 11 Oct 2023 14:15:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234998AbjJKSPP (ORCPT ); Wed, 11 Oct 2023 14:15:15 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C98A5AF for ; Wed, 11 Oct 2023 11:15:12 -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 56D0A1516; Wed, 11 Oct 2023 11:15:53 -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 B6BCC3F5A1; Wed, 11 Oct 2023 11:15:11 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux.dev, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v5 7/7] iommu: Clean up open-coded ownership checks Date: Wed, 11 Oct 2023 19:14:54 +0100 Message-Id: <0d68867cec0fb90578d50cc145f7f9a180407f20.1697047261.git.robin.murphy@arm.com> 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" Some drivers already implement their own defence against the possibility of being given someone else's device. Since this is now taken care of by the core code (and via a slightly different path from the original fwspec-based idea), let's clean them up. Reviewed-by: Jason Gunthorpe Signed-off-by: Robin Murphy Acked-by: Will Deacon Reviewed-by: Jerry Snitselaar --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 9 +-------- drivers/iommu/arm/arm-smmu/qcom_iommu.c | 16 +++------------- drivers/iommu/mtk_iommu.c | 7 +------ drivers/iommu/mtk_iommu_v1.c | 3 --- drivers/iommu/sprd-iommu.c | 8 +------- drivers/iommu/virtio-iommu.c | 3 --- 7 files changed, 6 insertions(+), 43 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/ar= m/arm-smmu-v3/arm-smmu-v3.c index e82bf1c449a3..01ea307c7791 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2653,9 +2653,6 @@ static struct iommu_device *arm_smmu_probe_device(str= uct device *dev) struct arm_smmu_master *master; struct iommu_fwspec *fwspec =3D dev_iommu_fwspec_get(dev); =20 - if (!fwspec || fwspec->ops !=3D &arm_smmu_ops) - return ERR_PTR(-ENODEV); - if (WARN_ON_ONCE(dev_iommu_priv_get(dev))) return ERR_PTR(-EBUSY); =20 diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-= smmu/arm-smmu.c index 4b83a3adacd6..4d09c0047892 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1116,11 +1116,6 @@ static int arm_smmu_attach_dev(struct iommu_domain *= domain, struct device *dev) struct arm_smmu_device *smmu; int ret; =20 - if (!fwspec || fwspec->ops !=3D &arm_smmu_ops) { - dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n"); - return -ENXIO; - } - /* * FIXME: The arch/arm DMA API code tries to attach devices to its own * domains between of_xlate() and probe_device() - we have no way to cope @@ -1357,10 +1352,8 @@ static struct iommu_device *arm_smmu_probe_device(st= ruct device *dev) fwspec =3D dev_iommu_fwspec_get(dev); if (ret) goto out_free; - } else if (fwspec && fwspec->ops =3D=3D &arm_smmu_ops) { - smmu =3D arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); } else { - return ERR_PTR(-ENODEV); + smmu =3D arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); } =20 ret =3D -EINVAL; diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/ar= m-smmu/qcom_iommu.c index 97b2122032b2..33f3c870086c 100644 --- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c +++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c @@ -79,16 +79,6 @@ static struct qcom_iommu_domain *to_qcom_iommu_domain(st= ruct iommu_domain *dom) =20 static const struct iommu_ops qcom_iommu_ops; =20 -static struct qcom_iommu_dev * to_iommu(struct device *dev) -{ - struct iommu_fwspec *fwspec =3D dev_iommu_fwspec_get(dev); - - if (!fwspec || fwspec->ops !=3D &qcom_iommu_ops) - return NULL; - - return dev_iommu_priv_get(dev); -} - static struct qcom_iommu_ctx * to_ctx(struct qcom_iommu_domain *d, unsigne= d asid) { struct qcom_iommu_dev *qcom_iommu =3D d->iommu; @@ -372,7 +362,7 @@ static void qcom_iommu_domain_free(struct iommu_domain = *domain) =20 static int qcom_iommu_attach_dev(struct iommu_domain *domain, struct devic= e *dev) { - struct qcom_iommu_dev *qcom_iommu =3D to_iommu(dev); + struct qcom_iommu_dev *qcom_iommu =3D dev_iommu_priv_get(dev); struct qcom_iommu_domain *qcom_domain =3D to_qcom_iommu_domain(domain); int ret; =20 @@ -404,7 +394,7 @@ static int qcom_iommu_identity_attach(struct iommu_doma= in *identity_domain, struct iommu_domain *domain =3D iommu_get_domain_for_dev(dev); struct qcom_iommu_domain *qcom_domain; struct iommu_fwspec *fwspec =3D dev_iommu_fwspec_get(dev); - struct qcom_iommu_dev *qcom_iommu =3D to_iommu(dev); + struct qcom_iommu_dev *qcom_iommu =3D dev_iommu_priv_get(dev); unsigned int i; =20 if (domain =3D=3D identity_domain || !domain) @@ -535,7 +525,7 @@ static bool qcom_iommu_capable(struct device *dev, enum= iommu_cap cap) =20 static struct iommu_device *qcom_iommu_probe_device(struct device *dev) { - struct qcom_iommu_dev *qcom_iommu =3D to_iommu(dev); + struct qcom_iommu_dev *qcom_iommu =3D dev_iommu_priv_get(dev); struct device_link *link; =20 if (!qcom_iommu) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 19ef50221c93..0a3698c33e19 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -863,16 +863,11 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iomm= u_domain *domain, static struct iommu_device *mtk_iommu_probe_device(struct device *dev) { struct iommu_fwspec *fwspec =3D dev_iommu_fwspec_get(dev); - struct mtk_iommu_data *data; + struct mtk_iommu_data *data =3D dev_iommu_priv_get(dev); struct device_link *link; struct device *larbdev; unsigned int larbid, larbidx, i; =20 - if (!fwspec || fwspec->ops !=3D &mtk_iommu_ops) - return ERR_PTR(-ENODEV); /* Not a iommu client device */ - - data =3D dev_iommu_priv_get(dev); - if (!MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_MM)) return &data->iommu; =20 diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index 67e044c1a7d9..25b41222abae 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -481,9 +481,6 @@ static struct iommu_device *mtk_iommu_v1_probe_device(s= truct device *dev) idx++; } =20 - if (!fwspec || fwspec->ops !=3D &mtk_iommu_v1_ops) - return ERR_PTR(-ENODEV); /* Not a iommu client device */ - data =3D dev_iommu_priv_get(dev); =20 /* Link the consumer device with the smi-larb device(supplier) */ diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c index 9c33ea6903f6..b15a8fe7ae8a 100644 --- a/drivers/iommu/sprd-iommu.c +++ b/drivers/iommu/sprd-iommu.c @@ -384,13 +384,7 @@ static phys_addr_t sprd_iommu_iova_to_phys(struct iomm= u_domain *domain, =20 static struct iommu_device *sprd_iommu_probe_device(struct device *dev) { - struct iommu_fwspec *fwspec =3D dev_iommu_fwspec_get(dev); - struct sprd_iommu_device *sdev; - - if (!fwspec || fwspec->ops !=3D &sprd_iommu_ops) - return ERR_PTR(-ENODEV); - - sdev =3D dev_iommu_priv_get(dev); + struct sprd_iommu_device *sdev =3D dev_iommu_priv_get(dev); =20 return &sdev->iommu; } diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 17dcd826f5c2..bb2e795a80d0 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -969,9 +969,6 @@ static struct iommu_device *viommu_probe_device(struct = device *dev) struct viommu_dev *viommu =3D NULL; struct iommu_fwspec *fwspec =3D dev_iommu_fwspec_get(dev); =20 - if (!fwspec || fwspec->ops !=3D &viommu_ops) - return ERR_PTR(-ENODEV); - viommu =3D viommu_get_by_fwnode(fwspec->iommu_fwnode); if (!viommu) return ERR_PTR(-ENODEV); --=20 2.39.2.101.g768bb238c484.dirty