From c13dbc1e24854908376c40ccaeb7a3a3c111e3af Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 15 Aug 2022 17:20:05 +0100 Subject: iommu: Always register bus notifiers 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 Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/7462347bf938bd6eedb629a3a318434f6516e712.1660572783.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 72 ++++++++++++++++++++++++++------------------------- 1 file changed, 37 insertions(+), 35 deletions(-) (limited to 'drivers/iommu/iommu.c') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 55d242f16824..49f0445f2654 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); @@ -1774,39 +1806,6 @@ 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. @@ -1835,9 +1834,12 @@ 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; } -- cgit v1.2.3