From patchwork Tue Jul 5 17:08:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12906876 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 8A2ACC43334 for ; Tue, 5 Jul 2022 17:10:26 +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=XvelI7NqpbavDAptpnaecyd8qqcECvmxhW7nvOgS4lw=; b=NQtLgYYpf31tCf Djf5f/mu3D3ZK1wOLrQ7GMOOIfBYByx5X8bWDnKUJ2qSOYc4b26VkjFNd2KXCcxP6ZONGM7FAQp6r SvknoGfP29PPTp2kEYsIZI63+h/wSghZKS3mSrrv7Q9ZqYgr41Fn/AY2wWBQX4tzlyM83jMxldg64 SC3tRGTpQk5LanJtTeYNz6SlV7bPuuoPFQ2iIRVXZXNmdxU4OQI6J1/nsq3jlpIeaLCKoGCuUuGN7 EaLGLxQFjGk40lhL74/7BoRD9r4xucFiPncqypWfR1zSNEi2uBmkjlYoh0eLqlQHp8vpJw5d9U3ET aNFKpr2nyoQXtO7gjJDg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8m3F-001gks-5g; Tue, 05 Jul 2022 17:09:29 +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 1o8m2f-001gLJ-5m for linux-arm-kernel@lists.infradead.org; Tue, 05 Jul 2022 17:08:55 +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 DE83B152B; Tue, 5 Jul 2022 10:08:50 -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 095E03F66F; Tue, 5 Jul 2022 10:08:48 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org Cc: will@kernel.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, baolu.lu@linux.intel.com, suravee.suthikulpanit@amd.com, vasant.hegde@amd.com, mjrosato@linux.ibm.com, gerald.schaefer@linux.ibm.com, schnelle@linux.ibm.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 04/15] iommu: Move bus setup to IOMMU device registration Date: Tue, 5 Jul 2022 18:08:27 +0100 Message-Id: <5b9b608af21b3c4353af042355973bac55397962.1657034828.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.36.1.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-20220705_100853_349868_DE597BB1 X-CRM114-Status: GOOD ( 15.75 ) 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 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 Reviewed-By: Krishna Reddy Signed-off-by: Robin Murphy Reviewed-by: Kevin Tian --- v3: Have iommu_device_register() return -EBUSY for conflicting ops rather than change that behaviour just yet. drivers/iommu/iommu.c | 54 ++++++++++++++++++++++++------------------- 1 file changed, 30 insertions(+), 24 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 514edc0eaa94..acb7b2ab0b79 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -180,6 +180,14 @@ 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 @@ -202,12 +210,32 @@ 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; + + if (bus->iommu_ops && bus->iommu_ops != ops) { + err = -EBUSY; + } else { + 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); @@ -1633,13 +1661,6 @@ 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) { @@ -1828,27 +1849,12 @@ 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);