From patchwork Thu Apr 28 13:18:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12830690 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 35CDEC433F5 for ; Thu, 28 Apr 2022 13:23:28 +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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vIckodEe0eZoum0+rouqr0pICpP4SzzoiZtRTD0ijEQ=; b=VIFFP0Wn8qUH4D Bzpale7MoAGUPgf5chJVZJkQijv00XxwzrHf9OW+cUZUgArGSjjoeQA5pJC5GvRM0xRcUuUuGY6jJ ZR5qmS0C62AuZmsyujundYbnBLqo2iNPMDha24fxFvq9FaADkU3+G4YIuuTdZ2NvF9DYTLTvpqHcn LrMmnIQOscXB2fle3UaoBVcPsZcBZv/kCx56b3GYaBN0frX8sU4vMn7r6xKcKlY2kW0+QL2IPmqeP LZvXh++MEg+qM1NEPt3zEpB5bbfl0MFY6yd7LgH81qfwZYXmJUf1WKwRRIIr7KRTBJnFSTxTNRW5T /4WZJAddr/o9N5ZuMzlA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nk45x-006zgH-T9; Thu, 28 Apr 2022 13:22:10 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nk42V-006xzY-K8 for linux-arm-kernel@lists.infradead.org; Thu, 28 Apr 2022 13:18:41 +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 61E7B1477; Thu, 28 Apr 2022 06:18:34 -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 0F8653F73B; Thu, 28 Apr 2022 06:18:31 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Subject: [PATCH v2 03/14] iommu: Move bus setup to IOMMU device registration Date: Thu, 28 Apr 2022 14:18:04 +0100 Message-Id: <1faba5b5c094379df3d99b8fec924ab50ad75482.1650890638.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.35.3.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-20220428_061835_840555_0EF19538 X-CRM114-Status: GOOD ( 15.63 ) 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: , Cc: jean-philippe@linaro.org, mjrosato@linux.ibm.com, sven@svenpeter.dev, zhang.lyra@gmail.com, robdclark@gmail.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, thierry.reding@gmail.com, linux-arm-kernel@lists.infradead.org, gerald.schaefer@linux.ibm.com, baolu.lu@linux.intel.com, yong.wu@mediatek.com, m.szyprowski@samsung.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Move the bus setup to iommu_device_register(). This should allow bus_iommu_probe() to be correctly replayed for multiple IOMMU instances, and leaves bus_set_iommu() as a glorified no-op to be cleaned up next. At this point we can also handle cleanup better than just rolling back the most-recently-touched bus upon failure - which may release devices owned by other already-registered instances, and still leave devices on other buses with dangling pointers to the failed instance. Now it's easy to clean up the exact footprint of a given instance, no more, no less. Tested-by: Marek Szyprowski Signed-off-by: Robin Murphy --- drivers/iommu/iommu.c | 51 +++++++++++++++++++++++-------------------- 1 file changed, 27 insertions(+), 24 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 6c4621afc8cf..c89af4dc54c2 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -175,6 +175,14 @@ static int __init iommu_subsys_init(void) } subsys_initcall(iommu_subsys_init); +static int remove_iommu_group(struct device *dev, void *data) +{ + if (dev->iommu && dev->iommu->iommu_dev == data) + iommu_release_device(dev); + + return 0; +} + /** * iommu_device_register() - Register an IOMMU hardware instance * @iommu: IOMMU handle for the instance @@ -197,12 +205,29 @@ int iommu_device_register(struct iommu_device *iommu, spin_lock(&iommu_device_lock); list_add_tail(&iommu->list, &iommu_device_list); spin_unlock(&iommu_device_lock); + + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) { + struct bus_type *bus = iommu_buses[i]; + int err; + + WARN_ON(bus->iommu_ops && bus->iommu_ops != ops); + bus->iommu_ops = ops; + err = bus_iommu_probe(bus); + if (err) { + iommu_device_unregister(iommu); + return err; + } + } + return 0; } EXPORT_SYMBOL_GPL(iommu_device_register); void iommu_device_unregister(struct iommu_device *iommu) { + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) + bus_for_each_dev(iommu_buses[i], NULL, iommu, remove_iommu_group); + spin_lock(&iommu_device_lock); list_del(&iommu->list); spin_unlock(&iommu_device_lock); @@ -1655,13 +1680,6 @@ static int probe_iommu_group(struct device *dev, void *data) return ret; } -static int remove_iommu_group(struct device *dev, void *data) -{ - iommu_release_device(dev); - - return 0; -} - static int iommu_bus_notifier(struct notifier_block *nb, unsigned long action, void *data) { @@ -1884,27 +1902,12 @@ static int iommu_bus_init(struct bus_type *bus) */ int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops) { - int err; - - if (ops == NULL) { - bus->iommu_ops = NULL; - return 0; - } - - if (bus->iommu_ops != NULL) + if (bus->iommu_ops && ops && bus->iommu_ops != ops) return -EBUSY; bus->iommu_ops = ops; - /* Do IOMMU specific setup for this bus-type */ - err = bus_iommu_probe(bus); - if (err) { - /* Clean up */ - bus_for_each_dev(bus, NULL, NULL, remove_iommu_group); - bus->iommu_ops = NULL; - } - - return err; + return 0; } EXPORT_SYMBOL_GPL(bus_set_iommu);