diff options
Diffstat (limited to 'drivers/iommu/iommu.c')
| -rw-r--r-- | drivers/iommu/iommu.c | 142 |
1 files changed, 95 insertions, 47 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 33e2a9b5d339..0d25468d53a6 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -148,7 +148,7 @@ 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[] = { +static const struct bus_type * const iommu_buses[] = { &platform_bus_type, #ifdef CONFIG_PCI &pci_bus_type, @@ -257,13 +257,6 @@ int iommu_device_register(struct iommu_device *iommu, /* We need to be able to take module references appropriately */ if (WARN_ON(is_module_address((unsigned long)ops) && !ops->owner)) return -EINVAL; - /* - * Temporarily enforce global restriction to a single driver. This was - * already the de-facto behaviour, since any possible combination of - * existing drivers would compete for at least the PCI or platform bus. - */ - if (iommu_buses[0]->iommu_ops && iommu_buses[0]->iommu_ops != ops) - return -EBUSY; iommu->ops = ops; if (hwdev) @@ -273,10 +266,8 @@ int iommu_device_register(struct iommu_device *iommu, list_add_tail(&iommu->list, &iommu_device_list); spin_unlock(&iommu_device_lock); - for (int i = 0; i < ARRAY_SIZE(iommu_buses) && !err; i++) { - iommu_buses[i]->iommu_ops = ops; + for (int i = 0; i < ARRAY_SIZE(iommu_buses) && !err; i++) err = bus_iommu_probe(iommu_buses[i]); - } if (err) iommu_device_unregister(iommu); return err; @@ -329,7 +320,6 @@ int iommu_device_register_bus(struct iommu_device *iommu, list_add_tail(&iommu->list, &iommu_device_list); spin_unlock(&iommu_device_lock); - bus->iommu_ops = ops; err = bus_iommu_probe(bus); if (err) { iommu_device_unregister_bus(iommu, bus, nb); @@ -368,6 +358,15 @@ static void dev_iommu_free(struct device *dev) kfree(param); } +/* + * Internal equivalent of device_iommu_mapped() for when we care that a device + * actually has API ops, and don't want false positives from VFIO-only groups. + */ +static bool dev_has_iommu(struct device *dev) +{ + return dev->iommu && dev->iommu->iommu_dev; +} + static u32 dev_iommu_get_max_pasids(struct device *dev) { u32 max_pasids = 0, bits = 0; @@ -489,11 +488,26 @@ DEFINE_MUTEX(iommu_probe_device_lock); static int __iommu_probe_device(struct device *dev, struct list_head *group_list) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + const struct iommu_ops *ops; + struct iommu_fwspec *fwspec; struct iommu_group *group; struct group_device *gdev; int ret; + /* + * For FDT-based systems and ACPI IORT/VIOT, drivers register IOMMU + * instances with non-NULL fwnodes, and client devices should have been + * identified with a fwspec by this point. Otherwise, we can currently + * assume that only one of Intel, AMD, s390, PAMU or legacy SMMUv2 can + * be present, and that any of their registered instances has suitable + * ops for probing, and thus cheekily co-opt the same mechanism. + */ + fwspec = dev_iommu_fwspec_get(dev); + if (fwspec && fwspec->ops) + ops = fwspec->ops; + else + ops = iommu_ops_from_fwnode(NULL); + if (!ops) return -ENODEV; /* @@ -618,7 +632,7 @@ static void __iommu_group_remove_device(struct device *dev) list_del(&device->list); __iommu_group_free_device(group, device); - if (dev->iommu && dev->iommu->iommu_dev) + if (dev_has_iommu(dev)) iommu_deinit_device(dev); else dev->iommu_group = NULL; @@ -817,7 +831,7 @@ int iommu_get_group_resv_regions(struct iommu_group *group, * Non-API groups still expose reserved_regions in sysfs, * so filter out calls that get here that way. */ - if (!device->dev->iommu) + if (!dev_has_iommu(device->dev)) break; INIT_LIST_HEAD(&dev_resv_regions); @@ -1223,6 +1237,12 @@ void iommu_group_remove_device(struct device *dev) } EXPORT_SYMBOL_GPL(iommu_group_remove_device); +static struct device *iommu_group_first_dev(struct iommu_group *group) +{ + lockdep_assert_held(&group->mutex); + return list_first_entry(&group->devices, struct group_device, list)->dev; +} + /** * iommu_group_for_each_dev - iterate over each device in the group * @group: the group @@ -1751,30 +1771,13 @@ __iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) } /* - * Returns the iommu_ops for the devices in an iommu group. - * - * It is assumed that all devices in an iommu group are managed by a single - * IOMMU unit. Therefore, this returns the dev_iommu_ops of the first device - * in the group. - */ -static const struct iommu_ops *group_iommu_ops(struct iommu_group *group) -{ - struct group_device *device = - list_first_entry(&group->devices, struct group_device, list); - - lockdep_assert_held(&group->mutex); - - return dev_iommu_ops(device->dev); -} - -/* * req_type of 0 means "auto" which means to select a domain based on * iommu_def_domain_type or what the driver actually supports. */ static struct iommu_domain * iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) { - const struct iommu_ops *ops = group_iommu_ops(group); + const struct iommu_ops *ops = dev_iommu_ops(iommu_group_first_dev(group)); struct iommu_domain *dom; lockdep_assert_held(&group->mutex); @@ -1854,7 +1857,7 @@ static int iommu_bus_notifier(struct notifier_block *nb, static int iommu_get_def_domain_type(struct iommu_group *group, struct device *dev, int cur_type) { - const struct iommu_ops *ops = group_iommu_ops(group); + const struct iommu_ops *ops = dev_iommu_ops(dev); int type; if (!ops->def_domain_type) @@ -2003,9 +2006,28 @@ int bus_iommu_probe(const struct bus_type *bus) return 0; } +/** + * iommu_present() - make platform-specific assumptions about an IOMMU + * @bus: bus to check + * + * Do not use this function. You want device_iommu_mapped() instead. + * + * Return: true if some IOMMU is present and aware of devices on the given bus; + * in general it may not be the only IOMMU, and it may not have anything to do + * with whatever device you are ultimately interested in. + */ bool iommu_present(const struct bus_type *bus) { - return bus->iommu_ops != NULL; + bool ret = false; + + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) { + if (iommu_buses[i] == bus) { + spin_lock(&iommu_device_lock); + ret = !list_empty(&iommu_device_list); + spin_unlock(&iommu_device_lock); + } + } + return ret; } EXPORT_SYMBOL_GPL(iommu_present); @@ -2021,7 +2043,7 @@ bool device_iommu_capable(struct device *dev, enum iommu_cap cap) { const struct iommu_ops *ops; - if (!dev->iommu || !dev->iommu->iommu_dev) + if (!dev_has_iommu(dev)) return false; ops = dev_iommu_ops(dev); @@ -2107,6 +2129,7 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, return ERR_PTR(-ENOMEM); domain->type = type; + domain->owner = ops; /* * If not already set, assume all sizes by default; the driver * may override this later @@ -2132,21 +2155,37 @@ static struct iommu_domain *__iommu_domain_alloc(const struct iommu_ops *ops, static struct iommu_domain * __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type) { - struct device *dev = - list_first_entry(&group->devices, struct group_device, list) - ->dev; + struct device *dev = iommu_group_first_dev(group); - return __iommu_domain_alloc(group_iommu_ops(group), dev, type); + return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type); +} + +static int __iommu_domain_alloc_dev(struct device *dev, void *data) +{ + const struct iommu_ops **ops = data; + + if (!dev_has_iommu(dev)) + return 0; + + if (WARN_ONCE(*ops && *ops != dev_iommu_ops(dev), + "Multiple IOMMU drivers present for bus %s, which the public IOMMU API can't fully support yet. You will still need to disable one or more for this to work, sorry!\n", + dev_bus_name(dev))) + return -EBUSY; + + *ops = dev_iommu_ops(dev); + return 0; } struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) { + const struct iommu_ops *ops = NULL; + int err = bus_for_each_dev(bus, NULL, &ops, __iommu_domain_alloc_dev); struct iommu_domain *domain; - if (bus == NULL || bus->iommu_ops == NULL) + if (err || !ops) return NULL; - domain = __iommu_domain_alloc(bus->iommu_ops, NULL, - IOMMU_DOMAIN_UNMANAGED); + + domain = __iommu_domain_alloc(ops, NULL, IOMMU_DOMAIN_UNMANAGED); if (IS_ERR(domain)) return NULL; return domain; @@ -2284,10 +2323,16 @@ struct iommu_domain *iommu_get_dma_domain(struct device *dev) static int __iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) { + struct device *dev; + if (group->domain && group->domain != group->default_domain && group->domain != group->blocking_domain) return -EBUSY; + dev = iommu_group_first_dev(group); + if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner) + return -EINVAL; + return __iommu_group_set_domain(group, domain); } @@ -3004,8 +3049,8 @@ EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); */ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat) { - if (dev->iommu && dev->iommu->iommu_dev) { - const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops = dev_iommu_ops(dev); if (ops->dev_enable_feat) return ops->dev_enable_feat(dev, feat); @@ -3020,8 +3065,8 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); */ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) { - if (dev->iommu && dev->iommu->iommu_dev) { - const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; + if (dev_has_iommu(dev)) { + const struct iommu_ops *ops = dev_iommu_ops(dev); if (ops->dev_disable_feat) return ops->dev_disable_feat(dev, feat); @@ -3481,6 +3526,9 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, if (!group) return -ENODEV; + if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner) + return -EINVAL; + mutex_lock(&group->mutex); curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL); if (curr) { |