From patchwork Fri Sep 15 16:58:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 13387258 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A52E0EED619 for ; Fri, 15 Sep 2023 16:59:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=GaGrZmIH6m17CPB8ljni0Zmh2O+5E+msIMO/VGCMzu4=; b=aAPDq9ML504LAh Frrx3a/2ZehDE+8n1CSxYox/n6UzKeMbc0Uqe6YANavM9TIs7t+dMwfLKB9W43a5ulu107OsFZ94/ NhHyb8ZF3FfOWbHS+MiC3W58ujZAJAazwvfitm+tBe/3Wxw7y74gqOVMWG3f71mTAbNsbkQM4VPHV Rz+XEEEUNB5rs8ETQ6uCqNoCQxU9ONmFCS/6FUBIY7k/zI3DhPkwEGdQijiNf+MeEKyPZ/QsX1hz7 n8ONzXbPFeuTYX8ZQ6dRm6SEIuH+al4ewZHUFddosesMRvlHvobJA9TzM5b2QNiYgtxpuSqNJZDYu y9wLJMhlAz00wPd84fSg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qhC9J-00B5RP-0B; Fri, 15 Sep 2023 16:58:33 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qhC9D-00B5PU-06 for linux-arm-kernel@lists.infradead.org; Fri, 15 Sep 2023 16:58:28 +0000 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230915_095827_162089_D8AFF6E9 X-CRM114-Status: GOOD ( 17.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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); } +/* + * Internal equivalent of device_iommu_mapped() for when we care that a device + * actually has API ops, and don't want false positives from VFIO-only groups. + */ +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 = 0, bits = 0; @@ -614,7 +623,7 @@ static void __iommu_group_remove_device(struct device *dev) 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 = NULL; @@ -1218,6 +1227,12 @@ void iommu_group_remove_device(struct device *dev) } EXPORT_SYMBOL_GPL(iommu_group_remove_device); +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_type *bus, static struct iommu_domain * iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) { - const struct bus_type *bus = - list_first_entry(&group->devices, struct group_device, list) - ->dev->bus; + const struct bus_type *bus = iommu_group_first_dev(group)->bus; struct iommu_domain *dom; lockdep_assert_held(&group->mutex); @@ -1912,7 +1925,7 @@ bool device_iommu_capable(struct device *dev, enum iommu_cap cap) { const struct iommu_ops *ops; - if (!dev->iommu || !dev->iommu->iommu_dev) + if (!dev_has_iommu(dev)) return false; ops = 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 feat) { - if (dev->iommu && dev->iommu->iommu_dev) { - const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops = dev_iommu_ops(dev); 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 = dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops = dev_iommu_ops(dev); if (ops->dev_disable_feat) return ops->dev_disable_feat(dev, feat); @@ -3190,21 +3203,18 @@ void iommu_device_unuse_default_domain(struct device *dev) static int __iommu_group_alloc_blocking_domain(struct iommu_group *group) { - struct group_device *dev = - list_first_entry(&group->devices, struct group_device, list); + struct device *dev = iommu_group_first_dev(group); if (group->blocking_domain) return 0; - group->blocking_domain = - __iommu_domain_alloc(dev->dev->bus, IOMMU_DOMAIN_BLOCKED); + group->blocking_domain = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_BLOCKED); if (!group->blocking_domain) { /* * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED * create an empty domain instead. */ - group->blocking_domain = __iommu_domain_alloc( - dev->dev->bus, IOMMU_DOMAIN_UNMANAGED); + group->blocking_domain = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_UNMANAGED); if (!group->blocking_domain) return -EINVAL; }