From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C4CEA2F21 for ; Mon, 15 Aug 2022 16:20:29 +0000 (UTC) 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 6E3F81D31; Mon, 15 Aug 2022 09:20:30 -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 359793F70D; Mon, 15 Aug 2022 09:20:28 -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, kevin.tian@intel.com, suravee.suthikulpanit@amd.com, vasant.hegde@amd.com, mjrosato@linux.ibm.com, schnelle@linux.ibm.com, linux-kernel@vger.kernel.org Subject: [PATCH v4 04/16] iommu: Always register bus notifiers Date: Mon, 15 Aug 2022 17:20:05 +0100 Message-Id: <7462347bf938bd6eedb629a3a318434f6516e712.1660572783.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.36.1.dirty In-Reply-To: References: Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Tested-by: Matthew Rosato # s390 Tested-by: Niklas Schnelle # s390 Signed-off-by: Robin Murphy --- v4: Squash iommu_bus_init() entirely, for maximum simplicity. Ignoring the return from bus_register_notifier() is common, so hopefully it's all pretty self-explanatory now. drivers/iommu/iommu.c | 72 ++++++++++++++++++++++--------------------- 1 file changed, 37 insertions(+), 35 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 780fb7071577..a8d14f2a1035 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 @@ -16,11 +17,13 @@ #include #include #include +#include #include #include #include #include #include +#include #include #include #include @@ -75,6 +78,8 @@ 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_notifier(struct notifier_block *nb, + unsigned long action, void *data); static int iommu_alloc_default_domain(struct iommu_group *group, struct device *dev); static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, @@ -103,6 +108,22 @@ 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 +#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS + &host1x_context_device_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. @@ -126,6 +147,8 @@ static const char *iommu_domain_type_str(unsigned int t) static int __init iommu_subsys_init(void) { + struct notifier_block *nb; + if (!(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API)) { if (IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH)) iommu_set_default_passthrough(false); @@ -152,6 +175,15 @@ static int __init iommu_subsys_init(void) (iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ? "(set via kernel command line)" : ""); + nb = kcalloc(ARRAY_SIZE(iommu_buses), sizeof(*nb), GFP_KERNEL); + if (!nb) + return -ENOMEM; + + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) { + nb[i].notifier_call = iommu_bus_notifier; + bus_register_notifier(iommu_buses[i], &nb[i]); + } + return 0; } subsys_initcall(iommu_subsys_init); @@ -1775,39 +1807,6 @@ int bus_iommu_probe(struct bus_type *bus) return ret; } -static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops) -{ - struct notifier_block *nb; - int err; - - nb = kzalloc(sizeof(struct notifier_block), 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); - - return err; -} - /** * bus_set_iommu - set iommu-callbacks for the bus * @bus: bus. @@ -1836,9 +1835,12 @@ 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; } -- 2.36.1.dirty