From mboxrd@z Thu Jan 1 00:00:00 1970 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 EFD48C433EF for ; Thu, 28 Apr 2022 13:18:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347018AbiD1NWA (ORCPT ); Thu, 28 Apr 2022 09:22:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346988AbiD1NVu (ORCPT ); Thu, 28 Apr 2022 09:21:50 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 052F3939D3 for ; Thu, 28 Apr 2022 06:18:32 -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 D244F1474; Thu, 28 Apr 2022 06:18:31 -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 C79543F73B; Thu, 28 Apr 2022 06:18:29 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux-foundation.org, sven@svenpeter.dev, robdclark@gmail.com, m.szyprowski@samsung.com, baolu.lu@linux.intel.com, yong.wu@mediatek.com, mjrosato@linux.ibm.com, gerald.schaefer@linux.ibm.com, zhang.lyra@gmail.com, thierry.reding@gmail.com, vdumpa@nvidia.com, jean-philippe@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 02/14] iommu: Always register bus notifiers Date: Thu, 28 Apr 2022 14:18:03 +0100 Message-Id: <26cc52902d2bd1232c2b777ff3b3c70248ca634d.1650890638.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.35.3.dirty In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The number of bus types that the IOMMU subsystem deals with is small and manageable, so pull that list into core code as a first step towards cleaning up all the boilerplate bus-awareness from drivers. Calling iommu_probe_device() before bus->iommu_ops is set will simply return -ENODEV and not break the notifier call chain, so there should be no harm in proactively registering all our bus notifiers at init time. Tested-by: Marek Szyprowski Reviewed-By: Krishna Reddy Signed-off-by: Robin Murphy --- drivers/iommu/iommu.c | 49 ++++++++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 21 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 00218b56a441..6c4621afc8cf 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -6,6 +6,7 @@ #define pr_fmt(fmt) "iommu: " fmt +#include #include #include #include @@ -22,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -74,6 +76,7 @@ static const char * const iommu_group_resv_type_string[] = { #define IOMMU_CMD_LINE_DMA_API BIT(0) #define IOMMU_CMD_LINE_STRICT BIT(1) +static int iommu_bus_init(struct bus_type *bus); static int iommu_alloc_default_domain(struct iommu_group *group, struct device *dev); static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, @@ -102,6 +105,19 @@ struct iommu_group_attribute iommu_group_attr_##_name = \ static LIST_HEAD(iommu_device_list); static DEFINE_SPINLOCK(iommu_device_lock); +static struct bus_type * const iommu_buses[] = { + &platform_bus_type, +#ifdef CONFIG_PCI + &pci_bus_type, +#endif +#ifdef CONFIG_ARM_AMBA + &amba_bustype, +#endif +#ifdef CONFIG_FSL_MC_BUS + &fsl_mc_bus_type, +#endif +}; + /* * Use a function instead of an array here because the domain-type is a * bit-field, so an array would waste memory. @@ -151,6 +167,10 @@ static int __init iommu_subsys_init(void) (iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ? "(set via kernel command line)" : ""); + /* If the system is so broken that this fails, it will WARN anyway */ + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) + iommu_bus_init(iommu_buses[i]); + return 0; } subsys_initcall(iommu_subsys_init); @@ -1832,35 +1852,19 @@ int bus_iommu_probe(struct bus_type *bus) return ret; } -static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops) +static int iommu_bus_init(struct bus_type *bus) { struct notifier_block *nb; int err; - nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL); + nb = kzalloc(sizeof(*nb), GFP_KERNEL); if (!nb) return -ENOMEM; nb->notifier_call = iommu_bus_notifier; - err = bus_register_notifier(bus, nb); if (err) - goto out_free; - - err = bus_iommu_probe(bus); - if (err) - goto out_err; - - - return 0; - -out_err: - /* Clean up */ - bus_for_each_dev(bus, NULL, NULL, remove_iommu_group); - bus_unregister_notifier(bus, nb); - -out_free: - kfree(nb); + kfree(nb); return err; } @@ -1893,9 +1897,12 @@ int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops) bus->iommu_ops = ops; /* Do IOMMU specific setup for this bus-type */ - err = iommu_bus_init(bus, ops); - if (err) + 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; } -- 2.35.3.dirty