From patchwork Fri Feb 28 15:46:32 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 869590 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B98B9271832; Fri, 28 Feb 2025 15:46:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740757621; cv=none; b=tHalEZDy9q5fUs7FR+1AK5XWmgOzxvGIT+XjESp2E9YezdUdXcmnW5EsFLJiR+k3EAyzjbdqERn8MR4ax6hn4PBm6jJ0KlwmP/hzbflaDCVgMiNlec6NjKenNz7TVYo1jJ3srxFaFvqgIqaZ+r+5LG7V5Sp+PgTE/tpBQW4T0+c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740757621; c=relaxed/simple; bh=mLeeVYrTUsBbxtedph86DS195K5D9XKDOeRf6Q9qHP8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=dwahahCgT8mQ6QilqKxBFUjdBU/CcjNwt78uGV6G2GMUCfySXcdCOxV5vGm1oLrceVPF89aHM9CrjazUEcSmG4RcQy6psS3wAIbp5FyOC2kyZrgXcxmSLJ0DhSxqcNEI+sPEOAiaGJ7AiMw5gaV34RXTuh9PwCwEeybhlMA/yhA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 454AE1BB0; Fri, 28 Feb 2025 07:47:13 -0800 (PST) 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 D32043F5A1; Fri, 28 Feb 2025 07:46:54 -0800 (PST) From: Robin Murphy To: Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , "Rafael J. Wysocki" , Len Brown , Russell King , Greg Kroah-Hartman , Danilo Krummrich , Stuart Yoder , Laurentiu Tudor , Nipun Gupta , Nikhil Agarwal , Joerg Roedel , Will Deacon , Rob Herring , Saravana Kannan , Bjorn Helgaas Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-pci@vger.kernel.org, Charan Teja Kalla Subject: [PATCH v2 3/4] iommu: Keep dev->iommu state consistent Date: Fri, 28 Feb 2025 15:46:32 +0000 Message-Id: X-Mailer: git-send-email 2.39.2.101.g768bb238c484.dirty In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 At the moment, if of_iommu_configure() allocates dev->iommu itself via iommu_fwspec_init(), then suffers a DT parsing failure, it cleans up the fwspec but leaves the empty dev_iommu hanging around. So far this is benign (if a tiny bit wasteful), but we'd like to be able to reason about dev->iommu having a consistent and unambiguous lifecycle. Thus make sure that the of_iommu cleanup undoes precisely whatever it did. Signed-off-by: Robin Murphy --- v2: New drivers/iommu/iommu-priv.h | 2 ++ drivers/iommu/iommu.c | 2 +- drivers/iommu/of_iommu.c | 6 +++++- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h index 17e245cf17bb..6574c1f97e14 100644 --- a/drivers/iommu/iommu-priv.h +++ b/drivers/iommu/iommu-priv.h @@ -17,6 +17,8 @@ static inline const struct iommu_ops *dev_iommu_ops(struct device *dev) return dev->iommu->iommu_dev->ops; } +void dev_iommu_free(struct device *dev); + const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode); static inline const struct iommu_ops *iommu_fwspec_ops(struct iommu_fwspec *fwspec) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 37b7088e129a..a3b45b84f42b 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -352,7 +352,7 @@ static struct dev_iommu *dev_iommu_get(struct device *dev) return param; } -static void dev_iommu_free(struct device *dev) +void dev_iommu_free(struct device *dev) { struct dev_iommu *param = dev->iommu; diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 97987cd78da9..e10a68b5ffde 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -116,6 +116,7 @@ static void of_pci_check_device_ats(struct device *dev, struct device_node *np) int of_iommu_configure(struct device *dev, struct device_node *master_np, const u32 *id) { + bool dev_iommu_present; int err; if (!master_np) @@ -127,6 +128,7 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np, mutex_unlock(&iommu_probe_device_lock); return 0; } + dev_iommu_present = dev->iommu; /* * We don't currently walk up the tree looking for a parent IOMMU. @@ -147,8 +149,10 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np, err = of_iommu_configure_device(master_np, dev, id); } - if (err) + if (err && dev_iommu_present) iommu_fwspec_free(dev); + else if (err && dev->iommu) + dev_iommu_free(dev); mutex_unlock(&iommu_probe_device_lock); if (!err && dev->bus)