diff options
Diffstat (limited to 'drivers/iommu/iommu.c')
| -rw-r--r-- | drivers/iommu/iommu.c | 4265 |
1 files changed, 4265 insertions, 0 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c new file mode 100644 index 000000000..cd1bca7ed --- /dev/null +++ b/drivers/iommu/iommu.c @@ -0,0 +1,4265 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2007-2008 Advanced Micro Devices, Inc. + * Author: Joerg Roedel <jroedel@suse.de> + */ + +#define pr_fmt(fmt) "iommu: " fmt + +#include <linux/amba/bus.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/bits.h> +#include <linux/bug.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/host1x_context_bus.h> +#include <linux/iommu.h> +#include <linux/iommufd.h> +#include <linux/idr.h> +#include <linux/err.h> +#include <linux/pci.h> +#include <linux/pci-ats.h> +#include <linux/bitops.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/fsl/mc.h> +#include <linux/module.h> +#include <linux/cc_platform.h> +#include <linux/cdx/cdx_bus.h> +#include <trace/events/iommu.h> +#include <linux/sched/mm.h> +#include <linux/msi.h> +#include <uapi/linux/iommufd.h> +#include <linux/generic_pt/iommu.h> + +#include "dma-iommu.h" +#include "iommu-priv.h" + +static struct kset *iommu_group_kset; +static DEFINE_IDA(iommu_group_ida); +static DEFINE_IDA(iommu_global_pasid_ida); + +static unsigned int iommu_def_domain_type __read_mostly; +static bool iommu_dma_strict __read_mostly = IS_ENABLED(CONFIG_IOMMU_DEFAULT_DMA_STRICT); +static u32 iommu_cmd_line __read_mostly; + +/* Tags used with xa_tag_pointer() in group->pasid_array */ +enum { IOMMU_PASID_ARRAY_DOMAIN = 0, IOMMU_PASID_ARRAY_HANDLE = 1 }; + +struct iommu_group { + struct kobject kobj; + struct kobject *devices_kobj; + struct list_head devices; + struct xarray pasid_array; + struct mutex mutex; + void *iommu_data; + void (*iommu_data_release)(void *iommu_data); + char *name; + int id; + struct iommu_domain *default_domain; + struct iommu_domain *blocking_domain; + struct iommu_domain *domain; + struct list_head entry; + unsigned int owner_cnt; + /* + * Number of devices in the group undergoing or awaiting recovery. + * If non-zero, concurrent domain attachments are rejected. + */ + unsigned int recovery_cnt; + void *owner; +}; + +struct group_device { + struct list_head list; + struct device *dev; + char *name; + /* + * Device is blocked for a pending recovery while its group->domain is + * retained. This can happen when: + * - Device is undergoing a reset + */ + bool blocked; + unsigned int reset_depth; +}; + +/* Iterate over each struct group_device in a struct iommu_group */ +#define for_each_group_device(group, pos) \ + list_for_each_entry(pos, &(group)->devices, list) + +static struct group_device *__dev_to_gdev(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + struct group_device *gdev; + + lockdep_assert_held(&group->mutex); + + for_each_group_device(group, gdev) { + if (gdev->dev == dev) + return gdev; + } + return NULL; +} + +struct iommu_group_attribute { + struct attribute attr; + ssize_t (*show)(struct iommu_group *group, char *buf); + ssize_t (*store)(struct iommu_group *group, + const char *buf, size_t count); +}; + +static const char * const iommu_group_resv_type_string[] = { + [IOMMU_RESV_DIRECT] = "direct", + [IOMMU_RESV_DIRECT_RELAXABLE] = "direct-relaxable", + [IOMMU_RESV_RESERVED] = "reserved", + [IOMMU_RESV_MSI] = "msi", + [IOMMU_RESV_SW_MSI] = "msi", +}; + +#define IOMMU_CMD_LINE_DMA_API BIT(0) +#define IOMMU_CMD_LINE_STRICT BIT(1) + +static int bus_iommu_probe(const struct bus_type *bus); +static int iommu_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data); +static void iommu_release_device(struct device *dev); +static int __iommu_attach_device(struct iommu_domain *domain, + struct device *dev, struct iommu_domain *old); +static int __iommu_attach_group(struct iommu_domain *domain, + struct iommu_group *group); +static struct iommu_domain *__iommu_paging_domain_alloc_flags(struct device *dev, + unsigned int type, + unsigned int flags); + +enum { + IOMMU_SET_DOMAIN_MUST_SUCCEED = 1 << 0, +}; + +static int __iommu_device_set_domain(struct iommu_group *group, + struct device *dev, + struct iommu_domain *new_domain, + struct iommu_domain *old_domain, + unsigned int flags); +static int __iommu_group_set_domain_internal(struct iommu_group *group, + struct iommu_domain *new_domain, + unsigned int flags); +static int __iommu_group_set_domain(struct iommu_group *group, + struct iommu_domain *new_domain) +{ + return __iommu_group_set_domain_internal(group, new_domain, 0); +} +static void __iommu_group_set_domain_nofail(struct iommu_group *group, + struct iommu_domain *new_domain) +{ + WARN_ON(__iommu_group_set_domain_internal( + group, new_domain, IOMMU_SET_DOMAIN_MUST_SUCCEED)); +} + +static int iommu_setup_default_domain(struct iommu_group *group, + int target_type); +static int iommu_create_device_direct_mappings(struct iommu_domain *domain, + struct device *dev); +static ssize_t iommu_group_store_type(struct iommu_group *group, + const char *buf, size_t count); +static struct group_device *iommu_group_alloc_device(struct iommu_group *group, + struct device *dev); +static void __iommu_group_free_device(struct iommu_group *group, + struct group_device *grp_dev); +static void iommu_domain_init(struct iommu_domain *domain, unsigned int type, + const struct iommu_ops *ops); + +#define IOMMU_GROUP_ATTR(_name, _mode, _show, _store) \ +struct iommu_group_attribute iommu_group_attr_##_name = \ + __ATTR(_name, _mode, _show, _store) + +#define to_iommu_group_attr(_attr) \ + container_of(_attr, struct iommu_group_attribute, attr) +#define to_iommu_group(_kobj) \ + container_of(_kobj, struct iommu_group, kobj) + +static LIST_HEAD(iommu_device_list); +static DEFINE_SPINLOCK(iommu_device_lock); + +static const 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 +#ifdef CONFIG_CDX_BUS + &cdx_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. + */ +static const char *iommu_domain_type_str(unsigned int t) +{ + switch (t) { + case IOMMU_DOMAIN_BLOCKED: + return "Blocked"; + case IOMMU_DOMAIN_IDENTITY: + return "Passthrough"; + case IOMMU_DOMAIN_UNMANAGED: + return "Unmanaged"; + case IOMMU_DOMAIN_DMA: + case IOMMU_DOMAIN_DMA_FQ: + return "Translated"; + case IOMMU_DOMAIN_PLATFORM: + return "Platform"; + default: + return "Unknown"; + } +} + +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); + else + iommu_set_default_translated(false); + + if (iommu_default_passthrough() && cc_platform_has(CC_ATTR_MEM_ENCRYPT)) { + pr_info("Memory encryption detected - Disabling default IOMMU Passthrough\n"); + iommu_set_default_translated(false); + } + } + + if (!iommu_default_passthrough() && !iommu_dma_strict) + iommu_def_domain_type = IOMMU_DOMAIN_DMA_FQ; + + pr_info("Default domain type: %s%s\n", + iommu_domain_type_str(iommu_def_domain_type), + (iommu_cmd_line & IOMMU_CMD_LINE_DMA_API) ? + " (set via kernel command line)" : ""); + + if (!iommu_default_passthrough()) + pr_info("DMA domain TLB invalidation policy: %s mode%s\n", + iommu_dma_strict ? "strict" : "lazy", + (iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ? + " (set via kernel command line)" : ""); + + nb = kzalloc_objs(*nb, ARRAY_SIZE(iommu_buses)); + if (!nb) + return -ENOMEM; + + iommu_debug_init(); + + 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); + +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 + * @ops: IOMMU ops to associate with the instance + * @hwdev: (optional) actual instance device, used for fwnode lookup + * + * Return: 0 on success, or an error. + */ +int iommu_device_register(struct iommu_device *iommu, + const struct iommu_ops *ops, struct device *hwdev) +{ + int err = 0; + + /* We need to be able to take module references appropriately */ + if (WARN_ON(is_module_address((unsigned long)ops) && !ops->owner)) + return -EINVAL; + + iommu->ops = ops; + if (hwdev) + iommu->fwnode = dev_fwnode(hwdev); + + 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) && !err; i++) + err = bus_iommu_probe(iommu_buses[i]); + if (err) + iommu_device_unregister(iommu); + else + WRITE_ONCE(iommu->ready, true); + return err; +} +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); + + /* Pairs with the alloc in generic_single_device_group() */ + iommu_group_put(iommu->singleton_group); + iommu->singleton_group = NULL; +} +EXPORT_SYMBOL_GPL(iommu_device_unregister); + +#if IS_ENABLED(CONFIG_IOMMUFD_TEST) +void iommu_device_unregister_bus(struct iommu_device *iommu, + const struct bus_type *bus, + struct notifier_block *nb) +{ + bus_unregister_notifier(bus, nb); + fwnode_remove_software_node(iommu->fwnode); + iommu_device_unregister(iommu); +} +EXPORT_SYMBOL_GPL(iommu_device_unregister_bus); + +/* + * Register an iommu driver against a single bus. This is only used by iommufd + * selftest to create a mock iommu driver. The caller must provide + * some memory to hold a notifier_block. + */ +int iommu_device_register_bus(struct iommu_device *iommu, + const struct iommu_ops *ops, + const struct bus_type *bus, + struct notifier_block *nb) +{ + int err; + + iommu->ops = ops; + nb->notifier_call = iommu_bus_notifier; + err = bus_register_notifier(bus, nb); + if (err) + return err; + + iommu->fwnode = fwnode_create_software_node(NULL, NULL); + if (IS_ERR(iommu->fwnode)) { + bus_unregister_notifier(bus, nb); + return PTR_ERR(iommu->fwnode); + } + + spin_lock(&iommu_device_lock); + list_add_tail(&iommu->list, &iommu_device_list); + spin_unlock(&iommu_device_lock); + + err = bus_iommu_probe(bus); + if (err) { + iommu_device_unregister_bus(iommu, bus, nb); + return err; + } + WRITE_ONCE(iommu->ready, true); + return 0; +} +EXPORT_SYMBOL_GPL(iommu_device_register_bus); + +int iommu_mock_device_add(struct device *dev, struct iommu_device *iommu) +{ + int rc; + + mutex_lock(&iommu_probe_device_lock); + rc = iommu_fwspec_init(dev, iommu->fwnode); + mutex_unlock(&iommu_probe_device_lock); + + if (rc) + return rc; + + rc = device_add(dev); + if (rc) + dev_iommu_free(dev); + return rc; +} +EXPORT_SYMBOL_GPL(iommu_mock_device_add); +#endif + +static struct dev_iommu *dev_iommu_get(struct device *dev) +{ + struct dev_iommu *param = dev->iommu; + + lockdep_assert_held(&iommu_probe_device_lock); + + if (param) + return param; + + param = kzalloc_obj(*param); + if (!param) + return NULL; + + mutex_init(¶m->lock); + dev->iommu = param; + return param; +} + +void dev_iommu_free(struct device *dev) +{ + struct dev_iommu *param = dev->iommu; + + dev->iommu = NULL; + if (param->fwspec) { + fwnode_handle_put(param->fwspec->iommu_fwnode); + kfree(param->fwspec); + } + 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; + int ret; + + if (dev_is_pci(dev)) { + ret = pci_max_pasids(to_pci_dev(dev)); + if (ret > 0) + max_pasids = ret; + } else { + ret = device_property_read_u32(dev, "pasid-num-bits", &bits); + if (!ret) + max_pasids = 1UL << bits; + } + + return min_t(u32, max_pasids, dev->iommu->iommu_dev->max_pasids); +} + +void dev_iommu_priv_set(struct device *dev, void *priv) +{ + /* FSL_PAMU does something weird */ + if (!IS_ENABLED(CONFIG_FSL_PAMU)) + lockdep_assert_held(&iommu_probe_device_lock); + dev->iommu->priv = priv; +} +EXPORT_SYMBOL_GPL(dev_iommu_priv_set); + +/* + * Init the dev->iommu and dev->iommu_group in the struct device and get the + * driver probed + */ +static int iommu_init_device(struct device *dev) +{ + const struct iommu_ops *ops; + struct iommu_device *iommu_dev; + struct iommu_group *group; + int ret; + + if (!dev_iommu_get(dev)) + return -ENOMEM; + /* + * For FDT-based systems and ACPI IORT/VIOT, the common firmware parsing + * is buried in the bus dma_configure path. Properly unpicking that is + * still a big job, so for now just invoke the whole thing. The device + * already having a driver bound means dma_configure has already run and + * found no IOMMU to wait for, so there's no point calling it again. + */ + if (!dev->iommu->fwspec && !dev->driver && dev->bus->dma_configure) { + mutex_unlock(&iommu_probe_device_lock); + dev->bus->dma_configure(dev); + mutex_lock(&iommu_probe_device_lock); + /* If another instance finished the job for us, skip it */ + if (!dev->iommu || dev->iommu_group) + return -ENODEV; + } + /* + * At this point, relevant devices either now have a fwspec which will + * match ops registered with a non-NULL fwnode, or we can reasonably + * 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. + */ + ops = iommu_fwspec_ops(dev->iommu->fwspec); + if (!ops) { + ret = -ENODEV; + goto err_free; + } + + if (!try_module_get(ops->owner)) { + ret = -EINVAL; + goto err_free; + } + + iommu_dev = ops->probe_device(dev); + if (IS_ERR(iommu_dev)) { + ret = PTR_ERR(iommu_dev); + goto err_module_put; + } + dev->iommu->iommu_dev = iommu_dev; + + ret = iommu_device_link(iommu_dev, dev); + if (ret) + goto err_release; + + group = ops->device_group(dev); + if (WARN_ON_ONCE(group == NULL)) + group = ERR_PTR(-EINVAL); + if (IS_ERR(group)) { + ret = PTR_ERR(group); + goto err_unlink; + } + dev->iommu_group = group; + + dev->iommu->max_pasids = dev_iommu_get_max_pasids(dev); + if (ops->is_attach_deferred) + dev->iommu->attach_deferred = ops->is_attach_deferred(dev); + return 0; + +err_unlink: + iommu_device_unlink(iommu_dev, dev); +err_release: + if (ops->release_device) + ops->release_device(dev); +err_module_put: + module_put(ops->owner); +err_free: + dev->iommu->iommu_dev = NULL; + dev_iommu_free(dev); + return ret; +} + +static void iommu_deinit_device(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + const struct iommu_ops *ops = dev_iommu_ops(dev); + + lockdep_assert_held(&group->mutex); + + iommu_device_unlink(dev->iommu->iommu_dev, dev); + + /* + * release_device() must stop using any attached domain on the device. + * If there are still other devices in the group, they are not affected + * by this callback. + * + * If the iommu driver provides release_domain, the core code ensures + * that domain is attached prior to calling release_device. Drivers can + * use this to enforce a translation on the idle iommu. Typically, the + * global static blocked_domain is a good choice. + * + * Otherwise, the iommu driver must set the device to either an identity + * or a blocking translation in release_device() and stop using any + * domain pointer, as it is going to be freed. + * + * Regardless, if a delayed attach never occurred, then the release + * should still avoid touching any hardware configuration either. + */ + if (!dev->iommu->attach_deferred && ops->release_domain) { + struct iommu_domain *release_domain = ops->release_domain; + + /* + * If the device requires direct mappings then it should not + * be parked on a BLOCKED domain during release as that would + * break the direct mappings. + */ + if (dev->iommu->require_direct && ops->identity_domain && + release_domain == ops->blocked_domain) + release_domain = ops->identity_domain; + + release_domain->ops->attach_dev(release_domain, dev, + group->domain); + } + + if (ops->release_device) + ops->release_device(dev); + + /* + * If this is the last driver to use the group then we must free the + * domains before we do the module_put(). + */ + if (list_empty(&group->devices)) { + if (group->default_domain) { + iommu_domain_free(group->default_domain); + group->default_domain = NULL; + } + if (group->blocking_domain) { + iommu_domain_free(group->blocking_domain); + group->blocking_domain = NULL; + } + group->domain = NULL; + } + + /* Caller must put iommu_group */ + dev->iommu_group = NULL; + module_put(ops->owner); + dev_iommu_free(dev); + if (IS_ENABLED(CONFIG_IOMMU_DMA)) + dev_clear_dma_iommu(dev); +} + +static struct iommu_domain *pasid_array_entry_to_domain(void *entry) +{ + if (xa_pointer_tag(entry) == IOMMU_PASID_ARRAY_DOMAIN) + return xa_untag_pointer(entry); + return ((struct iommu_attach_handle *)xa_untag_pointer(entry))->domain; +} + +DEFINE_MUTEX(iommu_probe_device_lock); + +static int __iommu_probe_device(struct device *dev, struct list_head *group_list) +{ + struct iommu_group *group; + struct group_device *gdev; + int ret; + + /* + * Serialise to avoid races between IOMMU drivers registering in + * parallel and/or the "replay" calls from ACPI/OF code via client + * driver probe. Once the latter have been cleaned up we should + * probably be able to use device_lock() here to minimise the scope, + * but for now enforcing a simple global ordering is fine. + */ + lockdep_assert_held(&iommu_probe_device_lock); + + /* Device is probed already if in a group */ + if (dev->iommu_group) + return 0; + + ret = iommu_init_device(dev); + if (ret) + return ret; + /* + * And if we do now see any replay calls, they would indicate someone + * misusing the dma_configure path outside bus code. + */ + if (dev->driver) + dev_WARN(dev, "late IOMMU probe at driver bind, something fishy here!\n"); + + group = dev->iommu_group; + gdev = iommu_group_alloc_device(group, dev); + mutex_lock(&group->mutex); + if (IS_ERR(gdev)) { + ret = PTR_ERR(gdev); + goto err_put_group; + } + + /* + * The gdev must be in the list before calling + * iommu_setup_default_domain() + */ + list_add_tail(&gdev->list, &group->devices); + WARN_ON(group->default_domain && !group->domain); + if (group->default_domain) + iommu_create_device_direct_mappings(group->default_domain, dev); + if (group->domain) { + ret = __iommu_device_set_domain(group, dev, group->domain, NULL, + 0); + if (ret) + goto err_remove_gdev; + } else if (!group->default_domain && !group_list) { + ret = iommu_setup_default_domain(group, 0); + if (ret) + goto err_remove_gdev; + } else if (!group->default_domain) { + /* + * With a group_list argument we defer the default_domain setup + * to the caller by providing a de-duplicated list of groups + * that need further setup. + */ + if (list_empty(&group->entry)) + list_add_tail(&group->entry, group_list); + } + + if (group->default_domain) + iommu_setup_dma_ops(dev, group->default_domain); + + mutex_unlock(&group->mutex); + + return 0; + +err_remove_gdev: + list_del(&gdev->list); + __iommu_group_free_device(group, gdev); +err_put_group: + iommu_deinit_device(dev); + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return ret; +} + +int iommu_probe_device(struct device *dev) +{ + const struct iommu_ops *ops; + int ret; + + mutex_lock(&iommu_probe_device_lock); + ret = __iommu_probe_device(dev, NULL); + mutex_unlock(&iommu_probe_device_lock); + if (ret) + return ret; + + ops = dev_iommu_ops(dev); + if (ops->probe_finalize) + ops->probe_finalize(dev); + + return 0; +} + +static void __iommu_group_free_device(struct iommu_group *group, + struct group_device *grp_dev) +{ + struct device *dev = grp_dev->dev; + + sysfs_remove_link(group->devices_kobj, grp_dev->name); + sysfs_remove_link(&dev->kobj, "iommu_group"); + + trace_remove_device_from_group(group->id, dev); + + /* + * If the group has become empty then ownership must have been + * released, and the current domain must be set back to NULL or + * the default domain. + */ + if (list_empty(&group->devices)) + WARN_ON(group->owner_cnt || + group->domain != group->default_domain); + + kfree(grp_dev->name); + kfree(grp_dev); +} + +/* Remove the iommu_group from the struct device. */ +static void __iommu_group_remove_device(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + struct group_device *device; + + mutex_lock(&group->mutex); + for_each_group_device(group, device) { + if (device->dev != dev) + continue; + + list_del(&device->list); + __iommu_group_free_device(group, device); + if (dev_has_iommu(dev)) + iommu_deinit_device(dev); + else + dev->iommu_group = NULL; + break; + } + mutex_unlock(&group->mutex); + + /* + * Pairs with the get in iommu_init_device() or + * iommu_group_add_device() + */ + iommu_group_put(group); +} + +static void iommu_release_device(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + + if (group) + __iommu_group_remove_device(dev); + + /* Free any fwspec if no iommu_driver was ever attached */ + if (dev->iommu) + dev_iommu_free(dev); +} + +static int __init iommu_set_def_domain_type(char *str) +{ + bool pt; + int ret; + + ret = kstrtobool(str, &pt); + if (ret) + return ret; + + if (pt) + iommu_set_default_passthrough(true); + else + iommu_set_default_translated(true); + + return 0; +} +early_param("iommu.passthrough", iommu_set_def_domain_type); + +static int __init iommu_dma_setup(char *str) +{ + int ret = kstrtobool(str, &iommu_dma_strict); + + if (!ret) + iommu_cmd_line |= IOMMU_CMD_LINE_STRICT; + return ret; +} +early_param("iommu.strict", iommu_dma_setup); + +void iommu_set_dma_strict(void) +{ + iommu_dma_strict = true; + if (iommu_def_domain_type == IOMMU_DOMAIN_DMA_FQ) + iommu_def_domain_type = IOMMU_DOMAIN_DMA; +} + +static ssize_t iommu_group_attr_show(struct kobject *kobj, + struct attribute *__attr, char *buf) +{ + struct iommu_group_attribute *attr = to_iommu_group_attr(__attr); + struct iommu_group *group = to_iommu_group(kobj); + ssize_t ret = -EIO; + + if (attr->show) + ret = attr->show(group, buf); + return ret; +} + +static ssize_t iommu_group_attr_store(struct kobject *kobj, + struct attribute *__attr, + const char *buf, size_t count) +{ + struct iommu_group_attribute *attr = to_iommu_group_attr(__attr); + struct iommu_group *group = to_iommu_group(kobj); + ssize_t ret = -EIO; + + if (attr->store) + ret = attr->store(group, buf, count); + return ret; +} + +static const struct sysfs_ops iommu_group_sysfs_ops = { + .show = iommu_group_attr_show, + .store = iommu_group_attr_store, +}; + +static int iommu_group_create_file(struct iommu_group *group, + struct iommu_group_attribute *attr) +{ + return sysfs_create_file(&group->kobj, &attr->attr); +} + +static void iommu_group_remove_file(struct iommu_group *group, + struct iommu_group_attribute *attr) +{ + sysfs_remove_file(&group->kobj, &attr->attr); +} + +static ssize_t iommu_group_show_name(struct iommu_group *group, char *buf) +{ + return sysfs_emit(buf, "%s\n", group->name); +} + +/** + * iommu_insert_resv_region - Insert a new region in the + * list of reserved regions. + * @new: new region to insert + * @regions: list of regions + * + * Elements are sorted by start address and overlapping segments + * of the same type are merged. + */ +static int iommu_insert_resv_region(struct iommu_resv_region *new, + struct list_head *regions) +{ + struct iommu_resv_region *iter, *tmp, *nr, *top; + LIST_HEAD(stack); + + nr = iommu_alloc_resv_region(new->start, new->length, + new->prot, new->type, GFP_KERNEL); + if (!nr) + return -ENOMEM; + + /* First add the new element based on start address sorting */ + list_for_each_entry(iter, regions, list) { + if (nr->start < iter->start || + (nr->start == iter->start && nr->type <= iter->type)) + break; + } + list_add_tail(&nr->list, &iter->list); + + /* Merge overlapping segments of type nr->type in @regions, if any */ + list_for_each_entry_safe(iter, tmp, regions, list) { + phys_addr_t top_end, iter_end = iter->start + iter->length - 1; + + /* no merge needed on elements of different types than @new */ + if (iter->type != new->type) { + list_move_tail(&iter->list, &stack); + continue; + } + + /* look for the last stack element of same type as @iter */ + list_for_each_entry_reverse(top, &stack, list) + if (top->type == iter->type) + goto check_overlap; + + list_move_tail(&iter->list, &stack); + continue; + +check_overlap: + top_end = top->start + top->length - 1; + + if (iter->start > top_end + 1) { + list_move_tail(&iter->list, &stack); + } else { + top->length = max(top_end, iter_end) - top->start + 1; + list_del(&iter->list); + kfree(iter); + } + } + list_splice(&stack, regions); + return 0; +} + +static int +iommu_insert_device_resv_regions(struct list_head *dev_resv_regions, + struct list_head *group_resv_regions) +{ + struct iommu_resv_region *entry; + int ret = 0; + + list_for_each_entry(entry, dev_resv_regions, list) { + ret = iommu_insert_resv_region(entry, group_resv_regions); + if (ret) + break; + } + return ret; +} + +int iommu_get_group_resv_regions(struct iommu_group *group, + struct list_head *head) +{ + struct group_device *device; + int ret = 0; + + mutex_lock(&group->mutex); + for_each_group_device(group, device) { + struct list_head dev_resv_regions; + + /* + * Non-API groups still expose reserved_regions in sysfs, + * so filter out calls that get here that way. + */ + if (!dev_has_iommu(device->dev)) + break; + + INIT_LIST_HEAD(&dev_resv_regions); + iommu_get_resv_regions(device->dev, &dev_resv_regions); + ret = iommu_insert_device_resv_regions(&dev_resv_regions, head); + iommu_put_resv_regions(device->dev, &dev_resv_regions); + if (ret) + break; + } + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions); + +static ssize_t iommu_group_show_resv_regions(struct iommu_group *group, + char *buf) +{ + struct iommu_resv_region *region, *next; + struct list_head group_resv_regions; + int offset = 0; + + INIT_LIST_HEAD(&group_resv_regions); + iommu_get_group_resv_regions(group, &group_resv_regions); + + list_for_each_entry_safe(region, next, &group_resv_regions, list) { + offset += sysfs_emit_at(buf, offset, "0x%016llx 0x%016llx %s\n", + (long long)region->start, + (long long)(region->start + + region->length - 1), + iommu_group_resv_type_string[region->type]); + kfree(region); + } + + return offset; +} + +static ssize_t iommu_group_show_type(struct iommu_group *group, + char *buf) +{ + char *type = "unknown"; + + mutex_lock(&group->mutex); + if (group->default_domain) { + switch (group->default_domain->type) { + case IOMMU_DOMAIN_BLOCKED: + type = "blocked"; + break; + case IOMMU_DOMAIN_IDENTITY: + type = "identity"; + break; + case IOMMU_DOMAIN_UNMANAGED: + type = "unmanaged"; + break; + case IOMMU_DOMAIN_DMA: + type = "DMA"; + break; + case IOMMU_DOMAIN_DMA_FQ: + type = "DMA-FQ"; + break; + } + } + mutex_unlock(&group->mutex); + + return sysfs_emit(buf, "%s\n", type); +} + +static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL); + +static IOMMU_GROUP_ATTR(reserved_regions, 0444, + iommu_group_show_resv_regions, NULL); + +static IOMMU_GROUP_ATTR(type, 0644, iommu_group_show_type, + iommu_group_store_type); + +static void iommu_group_release(struct kobject *kobj) +{ + struct iommu_group *group = to_iommu_group(kobj); + + pr_debug("Releasing group %d\n", group->id); + + if (group->iommu_data_release) + group->iommu_data_release(group->iommu_data); + + ida_free(&iommu_group_ida, group->id); + + /* Domains are free'd by iommu_deinit_device() */ + WARN_ON(group->default_domain); + WARN_ON(group->blocking_domain); + + kfree(group->name); + kfree(group); +} + +static const struct kobj_type iommu_group_ktype = { + .sysfs_ops = &iommu_group_sysfs_ops, + .release = iommu_group_release, +}; + +/** + * iommu_group_alloc - Allocate a new group + * + * This function is called by an iommu driver to allocate a new iommu + * group. The iommu group represents the minimum granularity of the iommu. + * Upon successful return, the caller holds a reference to the supplied + * group in order to hold the group until devices are added. Use + * iommu_group_put() to release this extra reference count, allowing the + * group to be automatically reclaimed once it has no devices or external + * references. + */ +struct iommu_group *iommu_group_alloc(void) +{ + struct iommu_group *group; + int ret; + + group = kzalloc_obj(*group); + if (!group) + return ERR_PTR(-ENOMEM); + + group->kobj.kset = iommu_group_kset; + mutex_init(&group->mutex); + INIT_LIST_HEAD(&group->devices); + INIT_LIST_HEAD(&group->entry); + xa_init(&group->pasid_array); + + ret = ida_alloc(&iommu_group_ida, GFP_KERNEL); + if (ret < 0) { + kfree(group); + return ERR_PTR(ret); + } + group->id = ret; + + ret = kobject_init_and_add(&group->kobj, &iommu_group_ktype, + NULL, "%d", group->id); + if (ret) { + kobject_put(&group->kobj); + return ERR_PTR(ret); + } + + group->devices_kobj = kobject_create_and_add("devices", &group->kobj); + if (!group->devices_kobj) { + kobject_put(&group->kobj); /* triggers .release & free */ + return ERR_PTR(-ENOMEM); + } + + /* + * The devices_kobj holds a reference on the group kobject, so + * as long as that exists so will the group. We can therefore + * use the devices_kobj for reference counting. + */ + kobject_put(&group->kobj); + + ret = iommu_group_create_file(group, + &iommu_group_attr_reserved_regions); + if (ret) { + kobject_put(group->devices_kobj); + return ERR_PTR(ret); + } + + ret = iommu_group_create_file(group, &iommu_group_attr_type); + if (ret) { + kobject_put(group->devices_kobj); + return ERR_PTR(ret); + } + + pr_debug("Allocated group %d\n", group->id); + + return group; +} +EXPORT_SYMBOL_GPL(iommu_group_alloc); + +/** + * iommu_group_get_iommudata - retrieve iommu_data registered for a group + * @group: the group + * + * iommu drivers can store data in the group for use when doing iommu + * operations. This function provides a way to retrieve it. Caller + * should hold a group reference. + */ +void *iommu_group_get_iommudata(struct iommu_group *group) +{ + return group->iommu_data; +} +EXPORT_SYMBOL_GPL(iommu_group_get_iommudata); + +/** + * iommu_group_set_iommudata - set iommu_data for a group + * @group: the group + * @iommu_data: new data + * @release: release function for iommu_data + * + * iommu drivers can store data in the group for use when doing iommu + * operations. This function provides a way to set the data after + * the group has been allocated. Caller should hold a group reference. + */ +void iommu_group_set_iommudata(struct iommu_group *group, void *iommu_data, + void (*release)(void *iommu_data)) +{ + group->iommu_data = iommu_data; + group->iommu_data_release = release; +} +EXPORT_SYMBOL_GPL(iommu_group_set_iommudata); + +/** + * iommu_group_set_name - set name for a group + * @group: the group + * @name: name + * + * Allow iommu driver to set a name for a group. When set it will + * appear in a name attribute file under the group in sysfs. + */ +int iommu_group_set_name(struct iommu_group *group, const char *name) +{ + int ret; + + if (group->name) { + iommu_group_remove_file(group, &iommu_group_attr_name); + kfree(group->name); + group->name = NULL; + if (!name) + return 0; + } + + group->name = kstrdup(name, GFP_KERNEL); + if (!group->name) + return -ENOMEM; + + ret = iommu_group_create_file(group, &iommu_group_attr_name); + if (ret) { + kfree(group->name); + group->name = NULL; + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(iommu_group_set_name); + +static int iommu_create_device_direct_mappings(struct iommu_domain *domain, + struct device *dev) +{ + struct iommu_resv_region *entry; + LIST_HEAD(mappings); + unsigned long pg_size; + int ret = 0; + + pg_size = domain->pgsize_bitmap ? 1UL << __ffs(domain->pgsize_bitmap) : 0; + + if (WARN_ON_ONCE(iommu_is_dma_domain(domain) && !pg_size)) + return -EINVAL; + + iommu_get_resv_regions(dev, &mappings); + + /* We need to consider overlapping regions for different devices */ + list_for_each_entry(entry, &mappings, list) { + dma_addr_t start, end, addr; + size_t map_size = 0; + + if (entry->type == IOMMU_RESV_DIRECT) + dev->iommu->require_direct = 1; + + if ((entry->type != IOMMU_RESV_DIRECT && + entry->type != IOMMU_RESV_DIRECT_RELAXABLE) || + !iommu_is_dma_domain(domain)) + continue; + + start = ALIGN(entry->start, pg_size); + end = ALIGN(entry->start + entry->length, pg_size); + + for (addr = start; addr <= end; addr += pg_size) { + phys_addr_t phys_addr; + + if (addr == end) + goto map_end; + + /* + * Return address by iommu_iova_to_phys for 0 is + * ambiguous. Offset to address 1 if addr is 0. + */ + phys_addr = iommu_iova_to_phys(domain, addr ? addr : 1); + if (!phys_addr) { + map_size += pg_size; + continue; + } + +map_end: + if (map_size) { + ret = iommu_map(domain, addr - map_size, + addr - map_size, map_size, + entry->prot, GFP_KERNEL); + if (ret) + goto out; + map_size = 0; + } + } + + } +out: + iommu_put_resv_regions(dev, &mappings); + + return ret; +} + +/* This is undone by __iommu_group_free_device() */ +static struct group_device *iommu_group_alloc_device(struct iommu_group *group, + struct device *dev) +{ + int ret, i = 0; + struct group_device *device; + + device = kzalloc_obj(*device); + if (!device) + return ERR_PTR(-ENOMEM); + + device->dev = dev; + + ret = sysfs_create_link(&dev->kobj, &group->kobj, "iommu_group"); + if (ret) + goto err_free_device; + + device->name = kasprintf(GFP_KERNEL, "%s", kobject_name(&dev->kobj)); +rename: + if (!device->name) { + ret = -ENOMEM; + goto err_remove_link; + } + + ret = sysfs_create_link_nowarn(group->devices_kobj, + &dev->kobj, device->name); + if (ret) { + if (ret == -EEXIST && i >= 0) { + /* + * Account for the slim chance of collision + * and append an instance to the name. + */ + kfree(device->name); + device->name = kasprintf(GFP_KERNEL, "%s.%d", + kobject_name(&dev->kobj), i++); + goto rename; + } + goto err_free_name; + } + + trace_add_device_to_group(group->id, dev); + + dev_info(dev, "Adding to iommu group %d\n", group->id); + + return device; + +err_free_name: + kfree(device->name); +err_remove_link: + sysfs_remove_link(&dev->kobj, "iommu_group"); +err_free_device: + kfree(device); + dev_err(dev, "Failed to add to iommu group %d: %d\n", group->id, ret); + return ERR_PTR(ret); +} + +/** + * iommu_group_add_device - add a device to an iommu group + * @group: the group into which to add the device (reference should be held) + * @dev: the device + * + * This function is called by an iommu driver to add a device into a + * group. Adding a device increments the group reference count. + */ +int iommu_group_add_device(struct iommu_group *group, struct device *dev) +{ + struct group_device *gdev; + + gdev = iommu_group_alloc_device(group, dev); + if (IS_ERR(gdev)) + return PTR_ERR(gdev); + + iommu_group_ref_get(group); + dev->iommu_group = group; + + mutex_lock(&group->mutex); + list_add_tail(&gdev->list, &group->devices); + mutex_unlock(&group->mutex); + return 0; +} +EXPORT_SYMBOL_GPL(iommu_group_add_device); + +/** + * iommu_group_remove_device - remove a device from its current group + * @dev: device to be removed + * + * This function is called by an iommu driver to remove the device from + * its current group. This decrements the iommu group reference count. + */ +void iommu_group_remove_device(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + + if (!group) + return; + + dev_info(dev, "Removing from iommu group %d\n", group->id); + + __iommu_group_remove_device(dev); +} +EXPORT_SYMBOL_GPL(iommu_group_remove_device); + +#if IS_ENABLED(CONFIG_LOCKDEP) && IS_ENABLED(CONFIG_IOMMU_API) +/** + * iommu_group_mutex_assert - Check device group mutex lock + * @dev: the device that has group param set + * + * This function is called by an iommu driver to check whether it holds + * group mutex lock for the given device or not. + * + * Note that this function must be called after device group param is set. + */ +void iommu_group_mutex_assert(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + + lockdep_assert_held(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_group_mutex_assert); +#endif + +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 + * @data: caller opaque data to be passed to callback function + * @fn: caller supplied callback function + * + * This function is called by group users to iterate over group devices. + * Callers should hold a reference count to the group during callback. + * The group->mutex is held across callbacks, which will block calls to + * iommu_group_add/remove_device. + */ +int iommu_group_for_each_dev(struct iommu_group *group, void *data, + int (*fn)(struct device *, void *)) +{ + struct group_device *device; + int ret = 0; + + mutex_lock(&group->mutex); + for_each_group_device(group, device) { + ret = fn(device->dev, data); + if (ret) + break; + } + mutex_unlock(&group->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_group_for_each_dev); + +/** + * iommu_group_get - Return the group for a device and increment reference + * @dev: get the group that this device belongs to + * + * This function is called by iommu drivers and users to get the group + * for the specified device. If found, the group is returned and the group + * reference in incremented, else NULL. + */ +struct iommu_group *iommu_group_get(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + + if (group) + kobject_get(group->devices_kobj); + + return group; +} +EXPORT_SYMBOL_GPL(iommu_group_get); + +/** + * iommu_group_ref_get - Increment reference on a group + * @group: the group to use, must not be NULL + * + * This function is called by iommu drivers to take additional references on an + * existing group. Returns the given group for convenience. + */ +struct iommu_group *iommu_group_ref_get(struct iommu_group *group) +{ + kobject_get(group->devices_kobj); + return group; +} +EXPORT_SYMBOL_GPL(iommu_group_ref_get); + +/** + * iommu_group_put - Decrement group reference + * @group: the group to use + * + * This function is called by iommu drivers and users to release the + * iommu group. Once the reference count is zero, the group is released. + */ +void iommu_group_put(struct iommu_group *group) +{ + if (group) + kobject_put(group->devices_kobj); +} +EXPORT_SYMBOL_GPL(iommu_group_put); + +/** + * iommu_group_id - Return ID for a group + * @group: the group to ID + * + * Return the unique ID for the group matching the sysfs group number. + */ +int iommu_group_id(struct iommu_group *group) +{ + return group->id; +} +EXPORT_SYMBOL_GPL(iommu_group_id); + +static struct iommu_group *get_pci_alias_group(struct pci_dev *pdev, + unsigned long *devfns); + +/* + * To consider a PCI device isolated, we require ACS to support Source + * Validation, Request Redirection, Completer Redirection, and Upstream + * Forwarding. This effectively means that devices cannot spoof their + * requester ID, requests and completions cannot be redirected, and all + * transactions are forwarded upstream, even as it passes through a + * bridge where the target device is downstream. + */ +#define REQ_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF) + +/* + * For multifunction devices which are not isolated from each other, find + * all the other non-isolated functions and look for existing groups. For + * each function, we also need to look for aliases to or from other devices + * that may already have a group. + */ +static struct iommu_group *get_pci_function_alias_group(struct pci_dev *pdev, + unsigned long *devfns) +{ + struct pci_dev *tmp = NULL; + struct iommu_group *group; + + if (!pdev->multifunction || pci_acs_enabled(pdev, REQ_ACS_FLAGS)) + return NULL; + + for_each_pci_dev(tmp) { + if (tmp == pdev || tmp->bus != pdev->bus || + PCI_SLOT(tmp->devfn) != PCI_SLOT(pdev->devfn) || + pci_acs_enabled(tmp, REQ_ACS_FLAGS)) + continue; + + group = get_pci_alias_group(tmp, devfns); + if (group) { + pci_dev_put(tmp); + return group; + } + } + + return NULL; +} + +/* + * Look for aliases to or from the given device for existing groups. DMA + * aliases are only supported on the same bus, therefore the search + * space is quite small (especially since we're really only looking at pcie + * device, and therefore only expect multiple slots on the root complex or + * downstream switch ports). It's conceivable though that a pair of + * multifunction devices could have aliases between them that would cause a + * loop. To prevent this, we use a bitmap to track where we've been. + */ +static struct iommu_group *get_pci_alias_group(struct pci_dev *pdev, + unsigned long *devfns) +{ + struct pci_dev *tmp = NULL; + struct iommu_group *group; + + if (test_and_set_bit(pdev->devfn & 0xff, devfns)) + return NULL; + + group = iommu_group_get(&pdev->dev); + if (group) + return group; + + for_each_pci_dev(tmp) { + if (tmp == pdev || tmp->bus != pdev->bus) + continue; + + /* We alias them or they alias us */ + if (pci_devs_are_dma_aliases(pdev, tmp)) { + group = get_pci_alias_group(tmp, devfns); + if (group) { + pci_dev_put(tmp); + return group; + } + + group = get_pci_function_alias_group(tmp, devfns); + if (group) { + pci_dev_put(tmp); + return group; + } + } + } + + return NULL; +} + +struct group_for_pci_data { + struct pci_dev *pdev; + struct iommu_group *group; +}; + +/* + * DMA alias iterator callback, return the last seen device. Stop and return + * the IOMMU group if we find one along the way. + */ +static int get_pci_alias_or_group(struct pci_dev *pdev, u16 alias, void *opaque) +{ + struct group_for_pci_data *data = opaque; + + data->pdev = pdev; + data->group = iommu_group_get(&pdev->dev); + + return data->group != NULL; +} + +/* + * Generic device_group call-back function. It just allocates one + * iommu-group per device. + */ +struct iommu_group *generic_device_group(struct device *dev) +{ + return iommu_group_alloc(); +} +EXPORT_SYMBOL_GPL(generic_device_group); + +/* + * Generic device_group call-back function. It just allocates one + * iommu-group per iommu driver instance shared by every device + * probed by that iommu driver. + */ +struct iommu_group *generic_single_device_group(struct device *dev) +{ + struct iommu_device *iommu = dev->iommu->iommu_dev; + + if (!iommu->singleton_group) { + struct iommu_group *group; + + group = iommu_group_alloc(); + if (IS_ERR(group)) + return group; + iommu->singleton_group = group; + } + return iommu_group_ref_get(iommu->singleton_group); +} +EXPORT_SYMBOL_GPL(generic_single_device_group); + +/* + * Use standard PCI bus topology, isolation features, and DMA alias quirks + * to find or create an IOMMU group for a device. + */ +struct iommu_group *pci_device_group(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct group_for_pci_data data; + struct pci_bus *bus; + struct iommu_group *group = NULL; + u64 devfns[4] = { 0 }; + + if (WARN_ON(!dev_is_pci(dev))) + return ERR_PTR(-EINVAL); + + /* + * Find the upstream DMA alias for the device. A device must not + * be aliased due to topology in order to have its own IOMMU group. + * If we find an alias along the way that already belongs to a + * group, use it. + */ + if (pci_for_each_dma_alias(pdev, get_pci_alias_or_group, &data)) + return data.group; + + pdev = data.pdev; + + /* + * Continue upstream from the point of minimum IOMMU granularity + * due to aliases to the point where devices are protected from + * peer-to-peer DMA by PCI ACS. Again, if we find an existing + * group, use it. + */ + for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) { + if (!bus->self) + continue; + + if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS)) + break; + + pdev = bus->self; + + group = iommu_group_get(&pdev->dev); + if (group) + return group; + } + + /* + * Look for existing groups on device aliases. If we alias another + * device or another device aliases us, use the same group. + */ + group = get_pci_alias_group(pdev, (unsigned long *)devfns); + if (group) + return group; + + /* + * Look for existing groups on non-isolated functions on the same + * slot and aliases of those funcions, if any. No need to clear + * the search bitmap, the tested devfns are still valid. + */ + group = get_pci_function_alias_group(pdev, (unsigned long *)devfns); + if (group) + return group; + + /* No shared group found, allocate new */ + return iommu_group_alloc(); +} +EXPORT_SYMBOL_GPL(pci_device_group); + +/* Get the IOMMU group for device on fsl-mc bus */ +struct iommu_group *fsl_mc_device_group(struct device *dev) +{ + struct device *cont_dev = fsl_mc_cont_dev(dev); + struct iommu_group *group; + + group = iommu_group_get(cont_dev); + if (!group) + group = iommu_group_alloc(); + return group; +} +EXPORT_SYMBOL_GPL(fsl_mc_device_group); + +static struct iommu_domain *__iommu_alloc_identity_domain(struct device *dev) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + struct iommu_domain *domain; + + if (ops->identity_domain) + return ops->identity_domain; + + if (ops->domain_alloc_identity) { + domain = ops->domain_alloc_identity(dev); + if (IS_ERR(domain)) + return domain; + } else { + return ERR_PTR(-EOPNOTSUPP); + } + + iommu_domain_init(domain, IOMMU_DOMAIN_IDENTITY, ops); + return domain; +} + +static struct iommu_domain * +__iommu_group_alloc_default_domain(struct iommu_group *group, int req_type) +{ + struct device *dev = iommu_group_first_dev(group); + struct iommu_domain *dom; + + if (group->default_domain && group->default_domain->type == req_type) + return group->default_domain; + + /* + * When allocating the DMA API domain assume that the driver is going to + * use PASID and make sure the RID's domain is PASID compatible. + */ + if (req_type & __IOMMU_DOMAIN_PAGING) { + dom = __iommu_paging_domain_alloc_flags(dev, req_type, + dev->iommu->max_pasids ? IOMMU_HWPT_ALLOC_PASID : 0); + + /* + * If driver does not support PASID feature then + * try to allocate non-PASID domain + */ + if (PTR_ERR(dom) == -EOPNOTSUPP) + dom = __iommu_paging_domain_alloc_flags(dev, req_type, 0); + + return dom; + } + + if (req_type == IOMMU_DOMAIN_IDENTITY) + return __iommu_alloc_identity_domain(dev); + + return ERR_PTR(-EINVAL); +} + +/* + * 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 = dev_iommu_ops(iommu_group_first_dev(group)); + struct iommu_domain *dom; + + lockdep_assert_held(&group->mutex); + + /* + * Allow legacy drivers to specify the domain that will be the default + * domain. This should always be either an IDENTITY/BLOCKED/PLATFORM + * domain. Do not use in new drivers. + */ + if (ops->default_domain) { + if (req_type != ops->default_domain->type) + return ERR_PTR(-EINVAL); + return ops->default_domain; + } + + if (req_type) + return __iommu_group_alloc_default_domain(group, req_type); + + /* The driver gave no guidance on what type to use, try the default */ + dom = __iommu_group_alloc_default_domain(group, iommu_def_domain_type); + if (!IS_ERR(dom)) + return dom; + + /* Otherwise IDENTITY and DMA_FQ defaults will try DMA */ + if (iommu_def_domain_type == IOMMU_DOMAIN_DMA) + return ERR_PTR(-EINVAL); + dom = __iommu_group_alloc_default_domain(group, IOMMU_DOMAIN_DMA); + if (IS_ERR(dom)) + return dom; + + pr_warn("Failed to allocate default IOMMU domain of type %u for group %s - Falling back to IOMMU_DOMAIN_DMA", + iommu_def_domain_type, group->name); + return dom; +} + +struct iommu_domain *iommu_group_default_domain(struct iommu_group *group) +{ + return group->default_domain; +} + +static int probe_iommu_group(struct device *dev, void *data) +{ + struct list_head *group_list = data; + int ret; + + mutex_lock(&iommu_probe_device_lock); + ret = __iommu_probe_device(dev, group_list); + mutex_unlock(&iommu_probe_device_lock); + if (ret == -ENODEV) + ret = 0; + + return ret; +} + +static int iommu_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + + if (action == BUS_NOTIFY_ADD_DEVICE) { + int ret; + + ret = iommu_probe_device(dev); + return (ret) ? NOTIFY_DONE : NOTIFY_OK; + } else if (action == BUS_NOTIFY_REMOVED_DEVICE) { + iommu_release_device(dev); + return NOTIFY_OK; + } + + return 0; +} + +/* + * Combine the driver's chosen def_domain_type across all the devices in a + * group. Drivers must give a consistent result. + */ +static int iommu_get_def_domain_type(struct iommu_group *group, + struct device *dev, int cur_type) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + int type; + + if (ops->default_domain) { + /* + * Drivers that declare a global static default_domain will + * always choose that. + */ + type = ops->default_domain->type; + } else { + if (ops->def_domain_type) + type = ops->def_domain_type(dev); + else + return cur_type; + } + if (!type || cur_type == type) + return cur_type; + if (!cur_type) + return type; + + dev_err_ratelimited( + dev, + "IOMMU driver error, requesting conflicting def_domain_type, %s and %s, for devices in group %u.\n", + iommu_domain_type_str(cur_type), iommu_domain_type_str(type), + group->id); + + /* + * Try to recover, drivers are allowed to force IDENTITY or DMA, IDENTITY + * takes precedence. + */ + if (type == IOMMU_DOMAIN_IDENTITY) + return type; + return cur_type; +} + +/* + * A target_type of 0 will select the best domain type. 0 can be returned in + * this case meaning the global default should be used. + */ +static int iommu_get_default_domain_type(struct iommu_group *group, + int target_type) +{ + struct device *untrusted = NULL; + struct group_device *gdev; + int driver_type = 0; + + lockdep_assert_held(&group->mutex); + + /* + * ARM32 drivers supporting CONFIG_ARM_DMA_USE_IOMMU can declare an + * identity_domain and it will automatically become their default + * domain. Later on ARM_DMA_USE_IOMMU will install its UNMANAGED domain. + * Override the selection to IDENTITY. + */ + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) { + static_assert(!(IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU) && + IS_ENABLED(CONFIG_IOMMU_DMA))); + driver_type = IOMMU_DOMAIN_IDENTITY; + } + + for_each_group_device(group, gdev) { + driver_type = iommu_get_def_domain_type(group, gdev->dev, + driver_type); + + if (dev_is_pci(gdev->dev) && to_pci_dev(gdev->dev)->untrusted) { + /* + * No ARM32 using systems will set untrusted, it cannot + * work. + */ + if (WARN_ON(IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))) + return -1; + untrusted = gdev->dev; + } + } + + /* + * If the common dma ops are not selected in kconfig then we cannot use + * IOMMU_DOMAIN_DMA at all. Force IDENTITY if nothing else has been + * selected. + */ + if (!IS_ENABLED(CONFIG_IOMMU_DMA)) { + if (WARN_ON(driver_type == IOMMU_DOMAIN_DMA)) + return -1; + if (!driver_type) + driver_type = IOMMU_DOMAIN_IDENTITY; + } + + if (untrusted) { + if (driver_type && driver_type != IOMMU_DOMAIN_DMA) { + dev_err_ratelimited( + untrusted, + "Device is not trusted, but driver is overriding group %u to %s, refusing to probe.\n", + group->id, iommu_domain_type_str(driver_type)); + return -1; + } + driver_type = IOMMU_DOMAIN_DMA; + } + + if (target_type) { + if (driver_type && target_type != driver_type) + return -1; + return target_type; + } + return driver_type; +} + +static void iommu_group_do_probe_finalize(struct device *dev) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + + if (ops->probe_finalize) + ops->probe_finalize(dev); +} + +static int bus_iommu_probe(const struct bus_type *bus) +{ + struct iommu_group *group, *next; + LIST_HEAD(group_list); + int ret; + + ret = bus_for_each_dev(bus, NULL, &group_list, probe_iommu_group); + if (ret) + return ret; + + list_for_each_entry_safe(group, next, &group_list, entry) { + struct group_device *gdev; + + mutex_lock(&group->mutex); + + /* Remove item from the list */ + list_del_init(&group->entry); + + /* + * We go to the trouble of deferred default domain creation so + * that the cross-group default domain type and the setup of the + * IOMMU_RESV_DIRECT will work correctly in non-hotpug scenarios. + */ + ret = iommu_setup_default_domain(group, 0); + if (ret) { + mutex_unlock(&group->mutex); + return ret; + } + for_each_group_device(group, gdev) + iommu_setup_dma_ops(gdev->dev, group->default_domain); + mutex_unlock(&group->mutex); + + /* + * FIXME: Mis-locked because the ops->probe_finalize() call-back + * of some IOMMU drivers calls arm_iommu_attach_device() which + * in-turn might call back into IOMMU core code, where it tries + * to take group->mutex, resulting in a deadlock. + */ + for_each_group_device(group, gdev) + iommu_group_do_probe_finalize(gdev->dev); + } + + return 0; +} + +/** + * device_iommu_capable() - check for a general IOMMU capability + * @dev: device to which the capability would be relevant, if available + * @cap: IOMMU capability + * + * Return: true if an IOMMU is present and supports the given capability + * for the given device, otherwise false. + */ +bool device_iommu_capable(struct device *dev, enum iommu_cap cap) +{ + const struct iommu_ops *ops; + + if (!dev_has_iommu(dev)) + return false; + + ops = dev_iommu_ops(dev); + if (!ops->capable) + return false; + + return ops->capable(dev, cap); +} +EXPORT_SYMBOL_GPL(device_iommu_capable); + +/** + * iommu_group_has_isolated_msi() - Compute msi_device_has_isolated_msi() + * for a group + * @group: Group to query + * + * IOMMU groups should not have differing values of + * msi_device_has_isolated_msi() for devices in a group. However nothing + * directly prevents this, so ensure mistakes don't result in isolation failures + * by checking that all the devices are the same. + */ +bool iommu_group_has_isolated_msi(struct iommu_group *group) +{ + struct group_device *group_dev; + bool ret = true; + + mutex_lock(&group->mutex); + for_each_group_device(group, group_dev) + ret &= msi_device_has_isolated_msi(group_dev->dev); + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_group_has_isolated_msi); + +/** + * iommu_set_fault_handler() - set a fault handler for an iommu domain + * @domain: iommu domain + * @handler: fault handler + * @token: user data, will be passed back to the fault handler + * + * This function should be used by IOMMU users which want to be notified + * whenever an IOMMU fault happens. + * + * The fault handler itself should return 0 on success, and an appropriate + * error code otherwise. + */ +void iommu_set_fault_handler(struct iommu_domain *domain, + iommu_fault_handler_t handler, + void *token) +{ + if (WARN_ON(!domain || domain->cookie_type != IOMMU_COOKIE_NONE)) + return; + + domain->cookie_type = IOMMU_COOKIE_FAULT_HANDLER; + domain->handler = handler; + domain->handler_token = token; +} +EXPORT_SYMBOL_GPL(iommu_set_fault_handler); + +static void iommu_domain_init(struct iommu_domain *domain, unsigned int type, + const struct iommu_ops *ops) +{ + domain->type = type; + domain->owner = ops; + if (!domain->ops) + domain->ops = ops->default_domain_ops; +} + +static struct iommu_domain * +__iommu_paging_domain_alloc_flags(struct device *dev, unsigned int type, + unsigned int flags) +{ + const struct iommu_ops *ops; + struct iommu_domain *domain; + + if (!dev_has_iommu(dev)) + return ERR_PTR(-ENODEV); + + ops = dev_iommu_ops(dev); + + if (ops->domain_alloc_paging && !flags) + domain = ops->domain_alloc_paging(dev); + else if (ops->domain_alloc_paging_flags) + domain = ops->domain_alloc_paging_flags(dev, flags, NULL); +#if IS_ENABLED(CONFIG_FSL_PAMU) + else if (ops->domain_alloc && !flags) + domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED); +#endif + else + return ERR_PTR(-EOPNOTSUPP); + + if (IS_ERR(domain)) + return domain; + if (!domain) + return ERR_PTR(-ENOMEM); + + iommu_domain_init(domain, type, ops); + return domain; +} + +/** + * iommu_paging_domain_alloc_flags() - Allocate a paging domain + * @dev: device for which the domain is allocated + * @flags: Bitmap of iommufd_hwpt_alloc_flags + * + * Allocate a paging domain which will be managed by a kernel driver. Return + * allocated domain if successful, or an ERR pointer for failure. + */ +struct iommu_domain *iommu_paging_domain_alloc_flags(struct device *dev, + unsigned int flags) +{ + return __iommu_paging_domain_alloc_flags(dev, + IOMMU_DOMAIN_UNMANAGED, flags); +} +EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc_flags); + +void iommu_domain_free(struct iommu_domain *domain) +{ + switch (domain->cookie_type) { + case IOMMU_COOKIE_DMA_IOVA: + iommu_put_dma_cookie(domain); + break; + case IOMMU_COOKIE_DMA_MSI: + iommu_put_msi_cookie(domain); + break; + case IOMMU_COOKIE_SVA: + mmdrop(domain->mm); + break; + default: + break; + } + if (domain->ops->free) + domain->ops->free(domain); +} +EXPORT_SYMBOL_GPL(iommu_domain_free); + +/* + * Put the group's domain back to the appropriate core-owned domain - either the + * standard kernel-mode DMA configuration or an all-DMA-blocked domain. + */ +static void __iommu_group_set_core_domain(struct iommu_group *group) +{ + struct iommu_domain *new_domain; + + if (group->owner) + new_domain = group->blocking_domain; + else + new_domain = group->default_domain; + + __iommu_group_set_domain_nofail(group, new_domain); +} + +static int __iommu_attach_device(struct iommu_domain *domain, + struct device *dev, struct iommu_domain *old) +{ + int ret; + + if (unlikely(domain->ops->attach_dev == NULL)) + return -ENODEV; + + ret = domain->ops->attach_dev(domain, dev, old); + if (ret) + return ret; + dev->iommu->attach_deferred = 0; + trace_attach_device_to_domain(dev); + return 0; +} + +/** + * iommu_attach_device - Attach an IOMMU domain to a device + * @domain: IOMMU domain to attach + * @dev: Device that will be attached + * + * Returns 0 on success and error code on failure + * + * Note that EINVAL can be treated as a soft failure, indicating + * that certain configuration of the domain is incompatible with + * the device. In this case attaching a different domain to the + * device may succeed. + */ +int iommu_attach_device(struct iommu_domain *domain, struct device *dev) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + int ret; + + if (!group) + return -ENODEV; + + /* + * Lock the group to make sure the device-count doesn't + * change while we are attaching + */ + mutex_lock(&group->mutex); + ret = -EINVAL; + if (list_count_nodes(&group->devices) != 1) + goto out_unlock; + + ret = __iommu_attach_group(domain, group); + +out_unlock: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_attach_device); + +int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain) +{ + struct group_device *gdev; + + /* + * This is called on the dma mapping fast path so avoid locking. This is + * racy, but we have an expectation that the driver will setup its DMAs + * inside probe while being single threaded to avoid racing. + */ + if (!dev->iommu || !dev->iommu->attach_deferred) + return 0; + + guard(mutex)(&dev->iommu_group->mutex); + + gdev = __dev_to_gdev(dev); + if (WARN_ON(!gdev)) + return -ENODEV; + + /* + * This is a concurrent attach during device recovery. Reject it until + * pci_dev_reset_iommu_done() attaches the device to group->domain. + * + * Note that this might fail the iommu_dma_map(). But there's nothing + * more we can do here. + */ + if (gdev->blocked) + return -EBUSY; + return __iommu_attach_device(domain, dev, NULL); +} + +void iommu_detach_device(struct iommu_domain *domain, struct device *dev) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + + if (!group) + return; + + mutex_lock(&group->mutex); + if (WARN_ON(domain != group->domain) || + WARN_ON(list_count_nodes(&group->devices) != 1)) + goto out_unlock; + __iommu_group_set_core_domain(group); + +out_unlock: + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_detach_device); + +/** + * iommu_get_domain_for_dev() - Return the DMA API domain pointer + * @dev: Device to query + * + * This function can be called within a driver bound to dev. The returned + * pointer is valid for the lifetime of the bound driver. + * + * It should not be called by drivers with driver_managed_dma = true. + */ +struct iommu_domain *iommu_get_domain_for_dev(struct device *dev) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + + if (!group) + return NULL; + + lockdep_assert_not_held(&group->mutex); + + return group->domain; +} +EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev); + +/** + * iommu_driver_get_domain_for_dev() - Return the driver-level domain pointer + * @dev: Device to query + * + * This function can be called by an iommu driver that wants to get the physical + * domain within an iommu callback function where group->mutex is held. + */ +struct iommu_domain *iommu_driver_get_domain_for_dev(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + struct group_device *gdev; + + lockdep_assert_held(&group->mutex); + + gdev = __dev_to_gdev(dev); + if (WARN_ON(!gdev)) + return NULL; + + /* + * Driver handles the low-level __iommu_attach_device(), including the + * one invoked by pci_dev_reset_iommu_done() re-attaching the device to + * the cached group->domain. In this case, the driver must get the old + * domain from group->blocking_domain rather than group->domain. This + * prevents it from re-attaching the device from group->domain (old) to + * group->domain (new). + */ + if (gdev->blocked) + return group->blocking_domain; + + return group->domain; +} +EXPORT_SYMBOL_GPL(iommu_driver_get_domain_for_dev); + +/* + * For IOMMU_DOMAIN_DMA implementations which already provide their own + * guarantees that the group and its default domain are valid and correct. + */ +struct iommu_domain *iommu_get_dma_domain(struct device *dev) +{ + return dev->iommu_group->default_domain; +} + +static void *iommu_make_pasid_array_entry(struct iommu_domain *domain, + struct iommu_attach_handle *handle) +{ + if (handle) { + handle->domain = domain; + return xa_tag_pointer(handle, IOMMU_PASID_ARRAY_HANDLE); + } + + return xa_tag_pointer(domain, IOMMU_PASID_ARRAY_DOMAIN); +} + +static bool domain_iommu_ops_compatible(const struct iommu_ops *ops, + struct iommu_domain *domain) +{ + if (domain->owner == ops) + return true; + + /* For static domains, owner isn't set. */ + if (domain == ops->blocked_domain || domain == ops->identity_domain) + return true; + + return false; +} + +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) || + !domain_iommu_ops_compatible(dev_iommu_ops(dev), domain)) + return -EINVAL; + + return __iommu_group_set_domain(group, domain); +} + +/** + * iommu_attach_group - Attach an IOMMU domain to an IOMMU group + * @domain: IOMMU domain to attach + * @group: IOMMU group that will be attached + * + * Returns 0 on success and error code on failure + * + * Note that EINVAL can be treated as a soft failure, indicating + * that certain configuration of the domain is incompatible with + * the group. In this case attaching a different domain to the + * group may succeed. + */ +int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) +{ + int ret; + + mutex_lock(&group->mutex); + ret = __iommu_attach_group(domain, group); + mutex_unlock(&group->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_attach_group); + +static int __iommu_device_set_domain(struct iommu_group *group, + struct device *dev, + struct iommu_domain *new_domain, + struct iommu_domain *old_domain, + unsigned int flags) +{ + int ret; + + /* + * If the device requires IOMMU_RESV_DIRECT then we cannot allow + * the blocking domain to be attached as it does not contain the + * required 1:1 mapping. This test effectively excludes the device + * being used with iommu_group_claim_dma_owner() which will block + * vfio and iommufd as well. + */ + if (dev->iommu->require_direct && + (new_domain->type == IOMMU_DOMAIN_BLOCKED || + new_domain == group->blocking_domain)) { + dev_warn(dev, + "Firmware has requested this device have a 1:1 IOMMU mapping, rejecting configuring the device without a 1:1 mapping. Contact your platform vendor.\n"); + return -EINVAL; + } + + if (dev->iommu->attach_deferred) { + if (new_domain == group->default_domain) + return 0; + dev->iommu->attach_deferred = 0; + } + + ret = __iommu_attach_device(new_domain, dev, old_domain); + if (ret) { + /* + * If we have a blocking domain then try to attach that in hopes + * of avoiding a UAF. Modern drivers should implement blocking + * domains as global statics that cannot fail. + */ + if ((flags & IOMMU_SET_DOMAIN_MUST_SUCCEED) && + group->blocking_domain && + group->blocking_domain != new_domain) + __iommu_attach_device(group->blocking_domain, dev, + old_domain); + return ret; + } + return 0; +} + +/* + * If 0 is returned the group's domain is new_domain. If an error is returned + * then the group's domain will be set back to the existing domain unless + * IOMMU_SET_DOMAIN_MUST_SUCCEED, otherwise an error is returned and the group's + * domains is left inconsistent. This is a driver bug to fail attach with a + * previously good domain. We try to avoid a kernel UAF because of this. + * + * IOMMU groups are really the natural working unit of the IOMMU, but the IOMMU + * API works on domains and devices. Bridge that gap by iterating over the + * devices in a group. Ideally we'd have a single device which represents the + * requestor ID of the group, but we also allow IOMMU drivers to create policy + * defined minimum sets, where the physical hardware may be able to distiguish + * members, but we wish to group them at a higher level (ex. untrusted + * multi-function PCI devices). Thus we attach each device. + */ +static int __iommu_group_set_domain_internal(struct iommu_group *group, + struct iommu_domain *new_domain, + unsigned int flags) +{ + struct group_device *last_gdev; + struct group_device *gdev; + int result; + int ret; + + lockdep_assert_held(&group->mutex); + + if (group->domain == new_domain) + return 0; + + if (WARN_ON(!new_domain)) + return -EINVAL; + + /* + * This is a concurrent attach during device recovery. Reject it until + * pci_dev_reset_iommu_done() attaches the device to group->domain, if + * IOMMU_SET_DOMAIN_MUST_SUCCEED is not set. + */ + if (group->recovery_cnt && !(flags & IOMMU_SET_DOMAIN_MUST_SUCCEED)) + return -EBUSY; + + /* + * Changing the domain is done by calling attach_dev() on the new + * domain. This switch does not have to be atomic and DMA can be + * discarded during the transition. DMA must only be able to access + * either new_domain or group->domain, never something else. + */ + result = 0; + for_each_group_device(group, gdev) { + /* + * Device under recovery is attached to group->blocking_domain. + * Don't change that. pci_dev_reset_iommu_done() will re-attach + * its domain to the updated group->domain, after the recovery. + */ + if (gdev->blocked) + continue; + ret = __iommu_device_set_domain(group, gdev->dev, new_domain, + group->domain, flags); + if (ret) { + result = ret; + /* + * Keep trying the other devices in the group. If a + * driver fails attach to an otherwise good domain, and + * does not support blocking domains, it should at least + * drop its reference on the current domain so we don't + * UAF. + */ + if (flags & IOMMU_SET_DOMAIN_MUST_SUCCEED) + continue; + goto err_revert; + } + } + group->domain = new_domain; + return result; + +err_revert: + /* + * This is called in error unwind paths. A well behaved driver should + * always allow us to attach to a domain that was already attached. + */ + last_gdev = gdev; + for_each_group_device(group, gdev) { + /* No need to revert the last gdev that failed to set domain */ + if (gdev == last_gdev) + break; + /* + * A NULL domain can happen only for first probe, in which case + * we leave group->domain as NULL and let release clean + * everything up. + */ + if (group->domain) + WARN_ON(__iommu_device_set_domain( + group, gdev->dev, group->domain, new_domain, + IOMMU_SET_DOMAIN_MUST_SUCCEED)); + } + return ret; +} + +void iommu_detach_group(struct iommu_domain *domain, struct iommu_group *group) +{ + mutex_lock(&group->mutex); + __iommu_group_set_core_domain(group); + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_detach_group); + +phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova) +{ + if (domain->type == IOMMU_DOMAIN_IDENTITY) + return iova; + + if (domain->type == IOMMU_DOMAIN_BLOCKED) + return 0; + + return domain->ops->iova_to_phys(domain, iova); +} +EXPORT_SYMBOL_GPL(iommu_iova_to_phys); + +static size_t iommu_pgsize(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, size_t *count) +{ + unsigned int pgsize_idx, pgsize_idx_next; + unsigned long pgsizes; + size_t offset, pgsize, pgsize_next; + size_t offset_end; + unsigned long addr_merge = paddr | iova; + + /* Page sizes supported by the hardware and small enough for @size */ + pgsizes = domain->pgsize_bitmap & GENMASK(__fls(size), 0); + + /* Constrain the page sizes further based on the maximum alignment */ + if (likely(addr_merge)) + pgsizes &= GENMASK(__ffs(addr_merge), 0); + + /* Make sure we have at least one suitable page size */ + BUG_ON(!pgsizes); + + /* Pick the biggest page size remaining */ + pgsize_idx = __fls(pgsizes); + pgsize = BIT(pgsize_idx); + if (!count) + return pgsize; + + /* Find the next biggest support page size, if it exists */ + pgsizes = domain->pgsize_bitmap & ~GENMASK(pgsize_idx, 0); + if (!pgsizes) + goto out_set_count; + + pgsize_idx_next = __ffs(pgsizes); + pgsize_next = BIT(pgsize_idx_next); + + /* + * There's no point trying a bigger page size unless the virtual + * and physical addresses are similarly offset within the larger page. + */ + if ((iova ^ paddr) & (pgsize_next - 1)) + goto out_set_count; + + /* Calculate the offset to the next page size alignment boundary */ + offset = pgsize_next - (addr_merge & (pgsize_next - 1)); + + /* + * If size is big enough to accommodate the larger page, reduce + * the number of smaller pages. + */ + if (!check_add_overflow(offset, pgsize_next, &offset_end) && + offset_end <= size) + size = offset; + +out_set_count: + *count = size >> pgsize_idx; + return pgsize; +} + +static int __iommu_map_domain_pgtbl(struct iommu_domain *domain, + unsigned long iova, phys_addr_t paddr, + size_t size, int prot, gfp_t gfp, + size_t *mapped) +{ + const struct iommu_domain_ops *ops = domain->ops; + unsigned int min_pagesz; + int ret = 0; + + if (WARN_ON(!ops->map_pages)) + return -ENODEV; + + /* find out the minimum page size supported */ + min_pagesz = 1 << __ffs(domain->pgsize_bitmap); + + /* + * both the virtual address and the physical one, as well as + * the size of the mapping, must be aligned (at least) to the + * size of the smallest page supported by the hardware + */ + if (!IS_ALIGNED(iova | paddr | size, min_pagesz)) { + pr_err("unaligned: iova 0x%lx pa %pa size 0x%zx min_pagesz 0x%x\n", + iova, &paddr, size, min_pagesz); + return -EINVAL; + } + + pr_debug("map: iova 0x%lx pa %pa size 0x%zx\n", iova, &paddr, size); + + while (size) { + size_t pgsize, count, op_mapped = 0; + + pgsize = iommu_pgsize(domain, iova, paddr, size, &count); + + pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx count %zu\n", + iova, &paddr, pgsize, count); + ret = ops->map_pages(domain, iova, paddr, pgsize, count, prot, + gfp, &op_mapped); + /* + * Some pages may have been mapped, even if an error occurred, + * so we should account for those so they can be unmapped. + */ + *mapped += op_mapped; + if (ret) + return ret; + + size -= op_mapped; + iova += op_mapped; + paddr += op_mapped; + } + return 0; +} + +int iommu_sync_map(struct iommu_domain *domain, unsigned long iova, size_t size) +{ + const struct iommu_domain_ops *ops = domain->ops; + + if (!ops->iotlb_sync_map) + return 0; + return ops->iotlb_sync_map(domain, iova, size); +} + +int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) +{ + struct pt_iommu *pt = iommupt_from_domain(domain); + size_t mapped = 0; + int ret; + + might_sleep_if(gfpflags_allow_blocking(gfp)); + + /* Discourage passing strange GFP flags or illegal domains */ + if (WARN_ON_ONCE(!(domain->type & __IOMMU_DOMAIN_PAGING) || + !domain->pgsize_bitmap || + (gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 | + __GFP_HIGHMEM)))) + return -EINVAL; + + if (pt) + ret = pt->ops->map_range(pt, iova, paddr, size, prot, gfp, + &mapped); + else + ret = __iommu_map_domain_pgtbl(domain, iova, paddr, size, prot, + gfp, &mapped); + + trace_map(iova, paddr, mapped); + iommu_debug_map(domain, paddr, mapped); + if (ret) { + iommu_unmap(domain, iova, mapped); + return ret; + } + return 0; +} + +int iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) +{ + int ret; + + ret = iommu_map_nosync(domain, iova, paddr, size, prot, gfp); + if (ret) + return ret; + + ret = iommu_sync_map(domain, iova, size); + if (ret) + iommu_unmap(domain, iova, size); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_map); + +static size_t +__iommu_unmap_domain_pgtbl(struct iommu_domain *domain, unsigned long iova, + size_t size, struct iommu_iotlb_gather *iotlb_gather) +{ + const struct iommu_domain_ops *ops = domain->ops; + size_t unmapped_page, unmapped = 0; + unsigned int min_pagesz; + + if (WARN_ON(!ops->unmap_pages)) + return 0; + + /* find out the minimum page size supported */ + min_pagesz = 1 << __ffs(domain->pgsize_bitmap); + + /* + * The virtual address, as well as the size of the mapping, must be + * aligned (at least) to the size of the smallest page supported + * by the hardware + */ + if (!IS_ALIGNED(iova | size, min_pagesz)) { + pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%x\n", + iova, size, min_pagesz); + return 0; + } + + pr_debug("unmap this: iova 0x%lx size 0x%zx\n", iova, size); + + /* + * Keep iterating until we either unmap 'size' bytes (or more) + * or we hit an area that isn't mapped. + */ + while (unmapped < size) { + size_t pgsize, count; + + pgsize = iommu_pgsize(domain, iova, iova, size - unmapped, &count); + unmapped_page = ops->unmap_pages(domain, iova, pgsize, count, iotlb_gather); + if (!unmapped_page) + break; + + pr_debug("unmapped: iova 0x%lx size 0x%zx\n", + iova, unmapped_page); + /* + * If the driver itself isn't using the gather, make sure + * it looks non-empty so iotlb_sync will still be called. + */ + if (iotlb_gather->start >= iotlb_gather->end) + iommu_iotlb_gather_add_range(iotlb_gather, iova, size); + + iova += unmapped_page; + unmapped += unmapped_page; + } + + return unmapped; +} + +static size_t __iommu_unmap(struct iommu_domain *domain, unsigned long iova, + size_t size, + struct iommu_iotlb_gather *iotlb_gather) +{ + struct pt_iommu *pt = iommupt_from_domain(domain); + size_t unmapped; + + if (WARN_ON_ONCE(!(domain->type & __IOMMU_DOMAIN_PAGING) || + !domain->pgsize_bitmap)) + return 0; + + iommu_debug_unmap_begin(domain, iova, size); + + if (pt) + unmapped = pt->ops->unmap_range(pt, iova, size, iotlb_gather); + else + unmapped = __iommu_unmap_domain_pgtbl(domain, iova, size, + iotlb_gather); + trace_unmap(iova, size, unmapped); + iommu_debug_unmap_end(domain, iova, size, unmapped); + return unmapped; +} + +/** + * iommu_unmap() - Remove mappings from a range of IOVA + * @domain: Domain to manipulate + * @iova: IO virtual address to start + * @size: Length of the range starting from @iova + * + * iommu_unmap() will remove a translation created by iommu_map(). It cannot + * subdivide a mapping created by iommu_map(), so it should be called with IOVA + * ranges that match what was passed to iommu_map(). The range can aggregate + * contiguous iommu_map() calls so long as no individual range is split. + * + * Returns: Number of bytes of IOVA unmapped. iova + res will be the point + * unmapping stopped. + */ +size_t iommu_unmap(struct iommu_domain *domain, + unsigned long iova, size_t size) +{ + struct iommu_iotlb_gather iotlb_gather; + size_t ret; + + iommu_iotlb_gather_init(&iotlb_gather); + ret = __iommu_unmap(domain, iova, size, &iotlb_gather); + iommu_iotlb_sync(domain, &iotlb_gather); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_unmap); + +/** + * iommu_unmap_fast() - Remove mappings from a range of IOVA without IOTLB sync + * @domain: Domain to manipulate + * @iova: IO virtual address to start + * @size: Length of the range starting from @iova + * @iotlb_gather: range information for a pending IOTLB flush + * + * iommu_unmap_fast() will remove a translation created by iommu_map(). + * It can't subdivide a mapping created by iommu_map(), so it should be + * called with IOVA ranges that match what was passed to iommu_map(). The + * range can aggregate contiguous iommu_map() calls so long as no individual + * range is split. + * + * Basically iommu_unmap_fast() is the same as iommu_unmap() but for callers + * which manage the IOTLB flushing externally to perform a batched sync. + * + * Returns: Number of bytes of IOVA unmapped. iova + res will be the point + * unmapping stopped. + */ +size_t iommu_unmap_fast(struct iommu_domain *domain, + unsigned long iova, size_t size, + struct iommu_iotlb_gather *iotlb_gather) +{ + return __iommu_unmap(domain, iova, size, iotlb_gather); +} +EXPORT_SYMBOL_GPL(iommu_unmap_fast); + +ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot, + gfp_t gfp) +{ + size_t len = 0, mapped = 0; + phys_addr_t start; + unsigned int i = 0; + int ret; + + while (i <= nents) { + phys_addr_t s_phys = sg_phys(sg); + + if (len && s_phys != start + len) { + ret = iommu_map_nosync(domain, iova + mapped, start, + len, prot, gfp); + if (ret) + goto out_err; + + mapped += len; + len = 0; + } + + if (sg_dma_is_bus_address(sg)) + goto next; + + if (len) { + len += sg->length; + } else { + len = sg->length; + start = s_phys; + } + +next: + if (++i < nents) + sg = sg_next(sg); + } + + ret = iommu_sync_map(domain, iova, mapped); + if (ret) + goto out_err; + + return mapped; + +out_err: + /* undo mappings already done */ + iommu_unmap(domain, iova, mapped); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_map_sg); + +/** + * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework + * @domain: the iommu domain where the fault has happened + * @dev: the device where the fault has happened + * @iova: the faulting address + * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...) + * + * This function should be called by the low-level IOMMU implementations + * whenever IOMMU faults happen, to allow high-level users, that are + * interested in such events, to know about them. + * + * This event may be useful for several possible use cases: + * - mere logging of the event + * - dynamic TLB/PTE loading + * - if restarting of the faulting device is required + * + * Returns 0 on success and an appropriate error code otherwise (if dynamic + * PTE/TLB loading will one day be supported, implementations will be able + * to tell whether it succeeded or not according to this return value). + * + * Specifically, -ENOSYS is returned if a fault handler isn't installed + * (though fault handlers can also return -ENOSYS, in case they want to + * elicit the default behavior of the IOMMU drivers). + */ +int report_iommu_fault(struct iommu_domain *domain, struct device *dev, + unsigned long iova, int flags) +{ + int ret = -ENOSYS; + + /* + * if upper layers showed interest and installed a fault handler, + * invoke it. + */ + if (domain->cookie_type == IOMMU_COOKIE_FAULT_HANDLER && + domain->handler) + ret = domain->handler(domain, dev, iova, flags, + domain->handler_token); + + trace_io_page_fault(dev, iova, flags); + return ret; +} +EXPORT_SYMBOL_GPL(report_iommu_fault); + +static int __init iommu_init(void) +{ + iommu_group_kset = kset_create_and_add("iommu_groups", + NULL, kernel_kobj); + BUG_ON(!iommu_group_kset); + + iommu_debugfs_setup(); + + return 0; +} +core_initcall(iommu_init); + +int iommu_set_pgtable_quirks(struct iommu_domain *domain, + unsigned long quirk) +{ + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -EINVAL; + if (!domain->ops->set_pgtable_quirks) + return -EINVAL; + return domain->ops->set_pgtable_quirks(domain, quirk); +} +EXPORT_SYMBOL_GPL(iommu_set_pgtable_quirks); + +/** + * iommu_get_resv_regions - get reserved regions + * @dev: device for which to get reserved regions + * @list: reserved region list for device + * + * This returns a list of reserved IOVA regions specific to this device. + * A domain user should not map IOVA in these ranges. + */ +void iommu_get_resv_regions(struct device *dev, struct list_head *list) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + + if (ops->get_resv_regions) + ops->get_resv_regions(dev, list); +} +EXPORT_SYMBOL_GPL(iommu_get_resv_regions); + +/** + * iommu_put_resv_regions - release reserved regions + * @dev: device for which to free reserved regions + * @list: reserved region list for device + * + * This releases a reserved region list acquired by iommu_get_resv_regions(). + */ +void iommu_put_resv_regions(struct device *dev, struct list_head *list) +{ + struct iommu_resv_region *entry, *next; + + list_for_each_entry_safe(entry, next, list, list) { + if (entry->free) + entry->free(dev, entry); + else + kfree(entry); + } +} +EXPORT_SYMBOL(iommu_put_resv_regions); + +struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start, + size_t length, int prot, + enum iommu_resv_type type, + gfp_t gfp) +{ + struct iommu_resv_region *region; + + region = kzalloc_obj(*region, gfp); + if (!region) + return NULL; + + INIT_LIST_HEAD(®ion->list); + region->start = start; + region->length = length; + region->prot = prot; + region->type = type; + return region; +} +EXPORT_SYMBOL_GPL(iommu_alloc_resv_region); + +void iommu_set_default_passthrough(bool cmd_line) +{ + if (cmd_line) + iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API; + iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY; +} + +void iommu_set_default_translated(bool cmd_line) +{ + if (cmd_line) + iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API; + iommu_def_domain_type = IOMMU_DOMAIN_DMA; +} + +bool iommu_default_passthrough(void) +{ + return iommu_def_domain_type == IOMMU_DOMAIN_IDENTITY; +} +EXPORT_SYMBOL_GPL(iommu_default_passthrough); + +static const struct iommu_device *iommu_from_fwnode(const struct fwnode_handle *fwnode) +{ + const struct iommu_device *iommu, *ret = NULL; + + spin_lock(&iommu_device_lock); + list_for_each_entry(iommu, &iommu_device_list, list) + if (iommu->fwnode == fwnode) { + ret = iommu; + break; + } + spin_unlock(&iommu_device_lock); + return ret; +} + +const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode) +{ + const struct iommu_device *iommu = iommu_from_fwnode(fwnode); + + return iommu ? iommu->ops : NULL; +} + +int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode) +{ + const struct iommu_device *iommu = iommu_from_fwnode(iommu_fwnode); + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + + if (!iommu) + return driver_deferred_probe_check_state(dev); + if (!dev->iommu && !READ_ONCE(iommu->ready)) + return -EPROBE_DEFER; + + if (fwspec) + return iommu->ops == iommu_fwspec_ops(fwspec) ? 0 : -EINVAL; + + if (!dev_iommu_get(dev)) + return -ENOMEM; + + /* Preallocate for the overwhelmingly common case of 1 ID */ + fwspec = kzalloc_flex(*fwspec, ids, 1); + if (!fwspec) + return -ENOMEM; + + fwnode_handle_get(iommu_fwnode); + fwspec->iommu_fwnode = iommu_fwnode; + dev_iommu_fwspec_set(dev, fwspec); + return 0; +} +EXPORT_SYMBOL_GPL(iommu_fwspec_init); + +void iommu_fwspec_free(struct device *dev) +{ + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + + if (fwspec) { + fwnode_handle_put(fwspec->iommu_fwnode); + kfree(fwspec); + dev_iommu_fwspec_set(dev, NULL); + } +} + +int iommu_fwspec_add_ids(struct device *dev, const u32 *ids, int num_ids) +{ + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + int i, new_num; + + if (!fwspec) + return -EINVAL; + + new_num = fwspec->num_ids + num_ids; + if (new_num > 1) { + fwspec = krealloc(fwspec, struct_size(fwspec, ids, new_num), + GFP_KERNEL); + if (!fwspec) + return -ENOMEM; + + dev_iommu_fwspec_set(dev, fwspec); + } + + for (i = 0; i < num_ids; i++) + fwspec->ids[fwspec->num_ids + i] = ids[i]; + + fwspec->num_ids = new_num; + return 0; +} +EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); + +/** + * iommu_setup_default_domain - Set the default_domain for the group + * @group: Group to change + * @target_type: Domain type to set as the default_domain + * + * Allocate a default domain and set it as the current domain on the group. If + * the group already has a default domain it will be changed to the target_type. + * When target_type is 0 the default domain is selected based on driver and + * system preferences. + */ +static int iommu_setup_default_domain(struct iommu_group *group, + int target_type) +{ + struct iommu_domain *old_dom = group->default_domain; + struct group_device *gdev; + struct iommu_domain *dom; + bool direct_failed; + int req_type; + int ret; + + lockdep_assert_held(&group->mutex); + + req_type = iommu_get_default_domain_type(group, target_type); + if (req_type < 0) + return -EINVAL; + + dom = iommu_group_alloc_default_domain(group, req_type); + if (IS_ERR(dom)) + return PTR_ERR(dom); + + if (group->default_domain == dom) + return 0; + + if (iommu_is_dma_domain(dom)) { + ret = iommu_get_dma_cookie(dom); + if (ret) { + iommu_domain_free(dom); + return ret; + } + } + + /* + * IOMMU_RESV_DIRECT and IOMMU_RESV_DIRECT_RELAXABLE regions must be + * mapped before their device is attached, in order to guarantee + * continuity with any FW activity + */ + direct_failed = false; + for_each_group_device(group, gdev) { + if (iommu_create_device_direct_mappings(dom, gdev->dev)) { + direct_failed = true; + dev_warn_once( + gdev->dev->iommu->iommu_dev->dev, + "IOMMU driver was not able to establish FW requested direct mapping."); + } + } + + /* We must set default_domain early for __iommu_device_set_domain */ + group->default_domain = dom; + if (!group->domain) { + /* + * Drivers are not allowed to fail the first domain attach. + * The only way to recover from this is to fail attaching the + * iommu driver and call ops->release_device. Put the domain + * in group->default_domain so it is freed after. + */ + ret = __iommu_group_set_domain_internal( + group, dom, IOMMU_SET_DOMAIN_MUST_SUCCEED); + if (WARN_ON(ret)) + goto out_free_old; + } else { + ret = __iommu_group_set_domain(group, dom); + if (ret) + goto err_restore_def_domain; + } + + /* + * Drivers are supposed to allow mappings to be installed in a domain + * before device attachment, but some don't. Hack around this defect by + * trying again after attaching. If this happens it means the device + * will not continuously have the IOMMU_RESV_DIRECT map. + */ + if (direct_failed) { + for_each_group_device(group, gdev) { + ret = iommu_create_device_direct_mappings(dom, gdev->dev); + if (ret) + goto err_restore_domain; + } + } + +out_free_old: + if (old_dom) + iommu_domain_free(old_dom); + return ret; + +err_restore_domain: + if (old_dom) + __iommu_group_set_domain_internal( + group, old_dom, IOMMU_SET_DOMAIN_MUST_SUCCEED); +err_restore_def_domain: + if (old_dom) { + iommu_domain_free(dom); + group->default_domain = old_dom; + } + return ret; +} + +/* + * Changing the default domain through sysfs requires the users to unbind the + * drivers from the devices in the iommu group, except for a DMA -> DMA-FQ + * transition. Return failure if this isn't met. + * + * We need to consider the race between this and the device release path. + * group->mutex is used here to guarantee that the device release path + * will not be entered at the same time. + */ +static ssize_t iommu_group_store_type(struct iommu_group *group, + const char *buf, size_t count) +{ + struct group_device *gdev; + int ret, req_type; + + if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) + return -EACCES; + + if (WARN_ON(!group) || !group->default_domain) + return -EINVAL; + + if (sysfs_streq(buf, "identity")) + req_type = IOMMU_DOMAIN_IDENTITY; + else if (sysfs_streq(buf, "DMA")) + req_type = IOMMU_DOMAIN_DMA; + else if (sysfs_streq(buf, "DMA-FQ")) + req_type = IOMMU_DOMAIN_DMA_FQ; + else if (sysfs_streq(buf, "auto")) + req_type = 0; + else + return -EINVAL; + + mutex_lock(&group->mutex); + /* We can bring up a flush queue without tearing down the domain. */ + if (req_type == IOMMU_DOMAIN_DMA_FQ && + group->default_domain->type == IOMMU_DOMAIN_DMA) { + ret = iommu_dma_init_fq(group->default_domain); + if (ret) + goto out_unlock; + + group->default_domain->type = IOMMU_DOMAIN_DMA_FQ; + ret = count; + goto out_unlock; + } + + /* Otherwise, ensure that device exists and no driver is bound. */ + if (list_empty(&group->devices) || group->owner_cnt) { + ret = -EPERM; + goto out_unlock; + } + + ret = iommu_setup_default_domain(group, req_type); + if (ret) + goto out_unlock; + + /* Make sure dma_ops is appropriatley set */ + for_each_group_device(group, gdev) + iommu_setup_dma_ops(gdev->dev, group->default_domain); + +out_unlock: + mutex_unlock(&group->mutex); + return ret ?: count; +} + +/** + * iommu_device_use_default_domain() - Device driver wants to handle device + * DMA through the kernel DMA API. + * @dev: The device. + * + * The device driver about to bind @dev wants to do DMA through the kernel + * DMA API. Return 0 if it is allowed, otherwise an error. + */ +int iommu_device_use_default_domain(struct device *dev) +{ + /* Caller is the driver core during the pre-probe path */ + struct iommu_group *group = dev->iommu_group; + int ret = 0; + + if (!group) + return 0; + + mutex_lock(&group->mutex); + /* We may race against bus_iommu_probe() finalising groups here */ + if (!group->default_domain) { + ret = -EPROBE_DEFER; + goto unlock_out; + } + if (group->owner_cnt) { + if (group->domain != group->default_domain || group->owner || + !xa_empty(&group->pasid_array)) { + ret = -EBUSY; + goto unlock_out; + } + } + + group->owner_cnt++; + +unlock_out: + mutex_unlock(&group->mutex); + return ret; +} + +/** + * iommu_device_unuse_default_domain() - Device driver stops handling device + * DMA through the kernel DMA API. + * @dev: The device. + * + * The device driver doesn't want to do DMA through kernel DMA API anymore. + * It must be called after iommu_device_use_default_domain(). + */ +void iommu_device_unuse_default_domain(struct device *dev) +{ + /* Caller is the driver core during the post-probe path */ + struct iommu_group *group = dev->iommu_group; + + if (!group) + return; + + mutex_lock(&group->mutex); + if (!WARN_ON(!group->owner_cnt || !xa_empty(&group->pasid_array))) + group->owner_cnt--; + + mutex_unlock(&group->mutex); +} + +static int __iommu_group_alloc_blocking_domain(struct iommu_group *group) +{ + struct device *dev = iommu_group_first_dev(group); + const struct iommu_ops *ops = dev_iommu_ops(dev); + struct iommu_domain *domain; + + if (group->blocking_domain) + return 0; + + if (ops->blocked_domain) { + group->blocking_domain = ops->blocked_domain; + return 0; + } + + /* + * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED create an + * empty PAGING domain instead. + */ + domain = iommu_paging_domain_alloc(dev); + if (IS_ERR(domain)) + return PTR_ERR(domain); + group->blocking_domain = domain; + return 0; +} + +static int __iommu_take_dma_ownership(struct iommu_group *group, void *owner) +{ + int ret; + + if ((group->domain && group->domain != group->default_domain) || + !xa_empty(&group->pasid_array)) + return -EBUSY; + + ret = __iommu_group_alloc_blocking_domain(group); + if (ret) + return ret; + ret = __iommu_group_set_domain(group, group->blocking_domain); + if (ret) + return ret; + + group->owner = owner; + group->owner_cnt++; + return 0; +} + +/** + * iommu_group_claim_dma_owner() - Set DMA ownership of a group + * @group: The group. + * @owner: Caller specified pointer. Used for exclusive ownership. + * + * This is to support backward compatibility for vfio which manages the dma + * ownership in iommu_group level. New invocations on this interface should be + * prohibited. Only a single owner may exist for a group. + */ +int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner) +{ + int ret = 0; + + if (WARN_ON(!owner)) + return -EINVAL; + + mutex_lock(&group->mutex); + if (group->owner_cnt) { + ret = -EPERM; + goto unlock_out; + } + + ret = __iommu_take_dma_ownership(group, owner); +unlock_out: + mutex_unlock(&group->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_group_claim_dma_owner); + +/** + * iommu_device_claim_dma_owner() - Set DMA ownership of a device + * @dev: The device. + * @owner: Caller specified pointer. Used for exclusive ownership. + * + * Claim the DMA ownership of a device. Multiple devices in the same group may + * concurrently claim ownership if they present the same owner value. Returns 0 + * on success and error code on failure + */ +int iommu_device_claim_dma_owner(struct device *dev, void *owner) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + int ret = 0; + + if (WARN_ON(!owner)) + return -EINVAL; + + if (!group) + return -ENODEV; + + mutex_lock(&group->mutex); + if (group->owner_cnt) { + if (group->owner != owner) { + ret = -EPERM; + goto unlock_out; + } + group->owner_cnt++; + goto unlock_out; + } + + ret = __iommu_take_dma_ownership(group, owner); +unlock_out: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_device_claim_dma_owner); + +static void __iommu_release_dma_ownership(struct iommu_group *group) +{ + if (WARN_ON(!group->owner_cnt || !group->owner || + !xa_empty(&group->pasid_array))) + return; + + group->owner_cnt = 0; + group->owner = NULL; + __iommu_group_set_domain_nofail(group, group->default_domain); +} + +/** + * iommu_group_release_dma_owner() - Release DMA ownership of a group + * @group: The group + * + * Release the DMA ownership claimed by iommu_group_claim_dma_owner(). + */ +void iommu_group_release_dma_owner(struct iommu_group *group) +{ + mutex_lock(&group->mutex); + __iommu_release_dma_ownership(group); + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_group_release_dma_owner); + +/** + * iommu_device_release_dma_owner() - Release DMA ownership of a device + * @dev: The device. + * + * Release the DMA ownership claimed by iommu_device_claim_dma_owner(). + */ +void iommu_device_release_dma_owner(struct device *dev) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + + mutex_lock(&group->mutex); + if (group->owner_cnt > 1) + group->owner_cnt--; + else + __iommu_release_dma_ownership(group); + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_device_release_dma_owner); + +/** + * iommu_group_dma_owner_claimed() - Query group dma ownership status + * @group: The group. + * + * This provides status query on a given group. It is racy and only for + * non-binding status reporting. + */ +bool iommu_group_dma_owner_claimed(struct iommu_group *group) +{ + unsigned int user; + + mutex_lock(&group->mutex); + user = group->owner_cnt; + mutex_unlock(&group->mutex); + + return user; +} +EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed); + +static void iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid, + struct iommu_domain *domain) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + struct iommu_domain *blocked_domain = ops->blocked_domain; + + WARN_ON(blocked_domain->ops->set_dev_pasid(blocked_domain, + dev, pasid, domain)); +} + +static int __iommu_set_group_pasid(struct iommu_domain *domain, + struct iommu_group *group, ioasid_t pasid, + struct iommu_domain *old) +{ + struct group_device *device, *last_gdev; + int ret; + + for_each_group_device(group, device) { + if (device->dev->iommu->max_pasids > 0) { + ret = domain->ops->set_dev_pasid(domain, device->dev, + pasid, old); + if (ret) + goto err_revert; + } + } + + return 0; + +err_revert: + last_gdev = device; + for_each_group_device(group, device) { + if (device == last_gdev) + break; + if (device->dev->iommu->max_pasids > 0) { + /* + * If no old domain, undo the succeeded devices/pasid. + * Otherwise, rollback the succeeded devices/pasid to + * the old domain. And it is a driver bug to fail + * attaching with a previously good domain. + */ + if (!old || + WARN_ON(old->ops->set_dev_pasid(old, device->dev, + pasid, domain))) + iommu_remove_dev_pasid(device->dev, pasid, domain); + } + } + return ret; +} + +static void __iommu_remove_group_pasid(struct iommu_group *group, + ioasid_t pasid, + struct iommu_domain *domain) +{ + struct group_device *device; + + for_each_group_device(group, device) { + /* + * A group-level detach cannot fail, even if there is a blocked + * device. In fact, blocked devices must be already detached for + * a pending device recovery. + */ + if (!device->blocked && device->dev->iommu->max_pasids > 0) + iommu_remove_dev_pasid(device->dev, pasid, domain); + } +} + +/* + * iommu_attach_device_pasid() - Attach a domain to pasid of device + * @domain: the iommu domain. + * @dev: the attached device. + * @pasid: the pasid of the device. + * @handle: the attach handle. + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle if it intends to pass a valid handle. + * + * Return: 0 on success, or an error. + */ +int iommu_attach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + struct group_device *device; + const struct iommu_ops *ops; + void *entry; + int ret; + + if (!group) + return -ENODEV; + + ops = dev_iommu_ops(dev); + + if (!domain->ops->set_dev_pasid || + !ops->blocked_domain || + !ops->blocked_domain->ops->set_dev_pasid) + return -EOPNOTSUPP; + + if (!domain_iommu_ops_compatible(ops, domain) || + pasid == IOMMU_NO_PASID) + return -EINVAL; + + mutex_lock(&group->mutex); + + /* + * This is a concurrent attach during device recovery. Reject it until + * pci_dev_reset_iommu_done() attaches the device to group->domain. + */ + if (group->recovery_cnt) { + ret = -EBUSY; + goto out_unlock; + } + + for_each_group_device(group, device) { + /* + * Skip PASID validation for devices without PASID support + * (max_pasids = 0). These devices cannot issue transactions + * with PASID, so they don't affect group's PASID usage. + */ + if ((device->dev->iommu->max_pasids > 0) && + (pasid >= device->dev->iommu->max_pasids)) { + ret = -EINVAL; + goto out_unlock; + } + } + + entry = iommu_make_pasid_array_entry(domain, handle); + + /* + * Entry present is a failure case. Use xa_insert() instead of + * xa_reserve(). + */ + ret = xa_insert(&group->pasid_array, pasid, XA_ZERO_ENTRY, GFP_KERNEL); + if (ret) + goto out_unlock; + + ret = __iommu_set_group_pasid(domain, group, pasid, NULL); + if (ret) { + xa_release(&group->pasid_array, pasid); + goto out_unlock; + } + + /* + * The xa_insert() above reserved the memory, and the group->mutex is + * held, this cannot fail. The new domain cannot be visible until the + * operation succeeds as we cannot tolerate PRIs becoming concurrently + * queued and then failing attach. + */ + WARN_ON(xa_is_err(xa_store(&group->pasid_array, + pasid, entry, GFP_KERNEL))); + +out_unlock: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_attach_device_pasid); + +/** + * iommu_replace_device_pasid - Replace the domain that a specific pasid + * of the device is attached to + * @domain: the new iommu domain + * @dev: the attached device. + * @pasid: the pasid of the device. + * @handle: the attach handle. + * + * This API allows the pasid to switch domains. The @pasid should have been + * attached. Otherwise, this fails. The pasid will keep the old configuration + * if replacement failed. + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle if it intends to pass a valid handle. + * + * Return 0 on success, or an error. + */ +int iommu_replace_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + struct iommu_attach_handle *entry; + struct iommu_domain *curr_domain; + void *curr; + int ret; + + if (!group) + return -ENODEV; + + if (!domain->ops->set_dev_pasid) + return -EOPNOTSUPP; + + if (!domain_iommu_ops_compatible(dev_iommu_ops(dev), domain) || + pasid == IOMMU_NO_PASID || !handle) + return -EINVAL; + + mutex_lock(&group->mutex); + + /* + * This is a concurrent attach during device recovery. Reject it until + * pci_dev_reset_iommu_done() attaches the device to group->domain. + */ + if (group->recovery_cnt) { + ret = -EBUSY; + goto out_unlock; + } + + entry = iommu_make_pasid_array_entry(domain, handle); + curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, + XA_ZERO_ENTRY, GFP_KERNEL); + if (xa_is_err(curr)) { + ret = xa_err(curr); + goto out_unlock; + } + + /* + * No domain (with or without handle) attached, hence not + * a replace case. + */ + if (!curr) { + xa_release(&group->pasid_array, pasid); + ret = -EINVAL; + goto out_unlock; + } + + /* + * Reusing handle is problematic as there are paths that refers + * the handle without lock. To avoid race, reject the callers that + * attempt it. + */ + if (curr == entry) { + WARN_ON(1); + ret = -EINVAL; + goto out_unlock; + } + + curr_domain = pasid_array_entry_to_domain(curr); + ret = 0; + + if (curr_domain != domain) { + ret = __iommu_set_group_pasid(domain, group, + pasid, curr_domain); + if (ret) + goto out_unlock; + } + + /* + * The above xa_cmpxchg() reserved the memory, and the + * group->mutex is held, this cannot fail. + */ + WARN_ON(xa_is_err(xa_store(&group->pasid_array, + pasid, entry, GFP_KERNEL))); + +out_unlock: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_NS_GPL(iommu_replace_device_pasid, "IOMMUFD_INTERNAL"); + +/* + * iommu_detach_device_pasid() - Detach the domain from pasid of device + * @domain: the iommu domain. + * @dev: the attached device. + * @pasid: the pasid of the device. + * + * The @domain must have been attached to @pasid of the @dev with + * iommu_attach_device_pasid(). + */ +void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, + ioasid_t pasid) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + + mutex_lock(&group->mutex); + __iommu_remove_group_pasid(group, pasid, domain); + xa_erase(&group->pasid_array, pasid); + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_detach_device_pasid); + +ioasid_t iommu_alloc_global_pasid(struct device *dev) +{ + int ret; + + /* max_pasids == 0 means that the device does not support PASID */ + if (!dev->iommu->max_pasids) + return IOMMU_PASID_INVALID; + + /* + * max_pasids is set up by vendor driver based on number of PASID bits + * supported but the IDA allocation is inclusive. + */ + ret = ida_alloc_range(&iommu_global_pasid_ida, IOMMU_FIRST_GLOBAL_PASID, + dev->iommu->max_pasids - 1, GFP_KERNEL); + return ret < 0 ? IOMMU_PASID_INVALID : ret; +} +EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid); + +void iommu_free_global_pasid(ioasid_t pasid) +{ + if (WARN_ON(pasid == IOMMU_PASID_INVALID)) + return; + + ida_free(&iommu_global_pasid_ida, pasid); +} +EXPORT_SYMBOL_GPL(iommu_free_global_pasid); + +/** + * iommu_attach_handle_get - Return the attach handle + * @group: the iommu group that domain was attached to + * @pasid: the pasid within the group + * @type: matched domain type, 0 for any match + * + * Return handle or ERR_PTR(-ENOENT) on none, ERR_PTR(-EBUSY) on mismatch. + * + * Return the attach handle to the caller. The life cycle of an iommu attach + * handle is from the time when the domain is attached to the time when the + * domain is detached. Callers are required to synchronize the call of + * iommu_attach_handle_get() with domain attachment and detachment. The attach + * handle can only be used during its life cycle. + */ +struct iommu_attach_handle * +iommu_attach_handle_get(struct iommu_group *group, ioasid_t pasid, unsigned int type) +{ + struct iommu_attach_handle *handle; + void *entry; + + xa_lock(&group->pasid_array); + entry = xa_load(&group->pasid_array, pasid); + if (!entry || xa_pointer_tag(entry) != IOMMU_PASID_ARRAY_HANDLE) { + handle = ERR_PTR(-ENOENT); + } else { + handle = xa_untag_pointer(entry); + if (type && handle->domain->type != type) + handle = ERR_PTR(-EBUSY); + } + xa_unlock(&group->pasid_array); + + return handle; +} +EXPORT_SYMBOL_NS_GPL(iommu_attach_handle_get, "IOMMUFD_INTERNAL"); + +/** + * iommu_attach_group_handle - Attach an IOMMU domain to an IOMMU group + * @domain: IOMMU domain to attach + * @group: IOMMU group that will be attached + * @handle: attach handle + * + * Returns 0 on success and error code on failure. + * + * This is a variant of iommu_attach_group(). It allows the caller to provide + * an attach handle and use it when the domain is attached. This is currently + * used by IOMMUFD to deliver the I/O page faults. + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle. + */ +int iommu_attach_group_handle(struct iommu_domain *domain, + struct iommu_group *group, + struct iommu_attach_handle *handle) +{ + void *entry; + int ret; + + if (!handle) + return -EINVAL; + + mutex_lock(&group->mutex); + entry = iommu_make_pasid_array_entry(domain, handle); + ret = xa_insert(&group->pasid_array, + IOMMU_NO_PASID, XA_ZERO_ENTRY, GFP_KERNEL); + if (ret) + goto out_unlock; + + ret = __iommu_attach_group(domain, group); + if (ret) { + xa_release(&group->pasid_array, IOMMU_NO_PASID); + goto out_unlock; + } + + /* + * The xa_insert() above reserved the memory, and the group->mutex is + * held, this cannot fail. The new domain cannot be visible until the + * operation succeeds as we cannot tolerate PRIs becoming concurrently + * queued and then failing attach. + */ + WARN_ON(xa_is_err(xa_store(&group->pasid_array, + IOMMU_NO_PASID, entry, GFP_KERNEL))); + +out_unlock: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_NS_GPL(iommu_attach_group_handle, "IOMMUFD_INTERNAL"); + +/** + * iommu_detach_group_handle - Detach an IOMMU domain from an IOMMU group + * @domain: IOMMU domain to attach + * @group: IOMMU group that will be attached + * + * Detach the specified IOMMU domain from the specified IOMMU group. + * It must be used in conjunction with iommu_attach_group_handle(). + */ +void iommu_detach_group_handle(struct iommu_domain *domain, + struct iommu_group *group) +{ + mutex_lock(&group->mutex); + __iommu_group_set_core_domain(group); + xa_erase(&group->pasid_array, IOMMU_NO_PASID); + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_NS_GPL(iommu_detach_group_handle, "IOMMUFD_INTERNAL"); + +/** + * iommu_replace_group_handle - replace the domain that a group is attached to + * @group: IOMMU group that will be attached to the new domain + * @new_domain: new IOMMU domain to replace with + * @handle: attach handle + * + * This API allows the group to switch domains without being forced to go to + * the blocking domain in-between. It allows the caller to provide an attach + * handle for the new domain and use it when the domain is attached. + * + * If the currently attached domain is a core domain (e.g. a default_domain), + * it will act just like the iommu_attach_group_handle(). + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle. + */ +int iommu_replace_group_handle(struct iommu_group *group, + struct iommu_domain *new_domain, + struct iommu_attach_handle *handle) +{ + void *curr, *entry; + int ret; + + if (!new_domain || !handle) + return -EINVAL; + + mutex_lock(&group->mutex); + entry = iommu_make_pasid_array_entry(new_domain, handle); + ret = xa_reserve(&group->pasid_array, IOMMU_NO_PASID, GFP_KERNEL); + if (ret) + goto err_unlock; + + ret = __iommu_group_set_domain(group, new_domain); + if (ret) + goto err_release; + + curr = xa_store(&group->pasid_array, IOMMU_NO_PASID, entry, GFP_KERNEL); + WARN_ON(xa_is_err(curr)); + + mutex_unlock(&group->mutex); + + return 0; +err_release: + xa_release(&group->pasid_array, IOMMU_NO_PASID); +err_unlock: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_NS_GPL(iommu_replace_group_handle, "IOMMUFD_INTERNAL"); + +/** + * pci_dev_reset_iommu_prepare() - Block IOMMU to prepare for a PCI device reset + * @pdev: PCI device that is going to enter a reset routine + * + * The PCIe r6.0, sec 10.3.1 IMPLEMENTATION NOTE recommends to disable and block + * ATS before initiating a reset. This means that a PCIe device during the reset + * routine wants to block any IOMMU activity: translation and ATS invalidation. + * + * This function attaches the device's RID/PASID(s) the group->blocking_domain, + * incrementing the group->recovery_cnt, to allow the IOMMU driver pausing any + * IOMMU activity while leaving the group->domain pointer intact. Later when the + * reset is finished, pci_dev_reset_iommu_done() can restore everything. + * + * Caller must use pci_dev_reset_iommu_prepare() with pci_dev_reset_iommu_done() + * before/after the core-level reset routine, to decrement the recovery_cnt. + * + * Return: 0 on success or negative error code if the preparation failed. + * + * These two functions are designed to be used by PCI reset functions that would + * not invoke any racy iommu_release_device(), since PCI sysfs node gets removed + * before it notifies with a BUS_NOTIFY_REMOVED_DEVICE. When using them in other + * case, callers must ensure there will be no racy iommu_release_device() call, + * which otherwise would UAF the dev->iommu_group pointer. + */ +int pci_dev_reset_iommu_prepare(struct pci_dev *pdev) +{ + struct iommu_group *group = pdev->dev.iommu_group; + struct group_device *gdev; + unsigned long pasid; + void *entry; + int ret; + + if (!pci_ats_supported(pdev) || !dev_has_iommu(&pdev->dev)) + return 0; + + guard(mutex)(&group->mutex); + + gdev = __dev_to_gdev(&pdev->dev); + if (WARN_ON(!gdev)) + return -ENODEV; + + if (gdev->reset_depth++) + return 0; + + ret = __iommu_group_alloc_blocking_domain(group); + if (ret) { + gdev->reset_depth--; + return ret; + } + + /* Stage RID domain at blocking_domain while retaining group->domain */ + if (group->domain != group->blocking_domain) { + ret = __iommu_attach_device(group->blocking_domain, &pdev->dev, + group->domain); + if (ret) { + gdev->reset_depth--; + return ret; + } + } + + /* + * Update gdev->blocked upon the domain change, as it is used to return + * the correct domain in iommu_driver_get_domain_for_dev() that might be + * called in a set_dev_pasid callback function. + */ + gdev->blocked = true; + + /* + * Stage PASID domains at blocking_domain while retaining pasid_array. + * + * The pasid_array is mostly fenced by group->mutex, except one reader + * in iommu_attach_handle_get(), so it's safe to read without xa_lock. + */ + if (pdev->dev.iommu->max_pasids > 0) { + xa_for_each_start(&group->pasid_array, pasid, entry, 1) { + struct iommu_domain *pasid_dom = + pasid_array_entry_to_domain(entry); + + iommu_remove_dev_pasid(&pdev->dev, pasid, pasid_dom); + } + } + + group->recovery_cnt++; + return ret; +} +EXPORT_SYMBOL_GPL(pci_dev_reset_iommu_prepare); + +static int __group_device_cmp_dma_alias(struct pci_dev *dev, u16 alias, + void *data) +{ + return alias == *(u16 *)data; +} + +static int group_device_cmp_dma_alias(struct pci_dev *dev, u16 alias, + void *data) +{ + return pci_for_each_dma_alias(data, __group_device_cmp_dma_alias, + &alias); +} + +static bool group_device_dma_alias_is_blocked(struct iommu_group *group, + struct group_device *gdev) +{ + struct group_device *sibling; + + lockdep_assert_held(&group->mutex); + + if (!dev_is_pci(gdev->dev)) + return false; + + for_each_group_device(group, sibling) { + if (sibling == gdev || !sibling->blocked || + !dev_is_pci(sibling->dev)) + continue; + if (pci_for_each_dma_alias(to_pci_dev(gdev->dev), + group_device_cmp_dma_alias, + to_pci_dev(sibling->dev))) + return true; + } + return false; +} + +/** + * pci_dev_reset_iommu_done() - Restore IOMMU after a PCI device reset is done + * @pdev: PCI device that has finished a reset routine + * + * After a PCIe device finishes a reset routine, it wants to restore its IOMMU + * activity, including new translation and cache invalidation, by re-attaching + * all RID/PASID of the device back to the domains retained in the core-level + * structure. + * + * Caller must pair it with a successful pci_dev_reset_iommu_prepare(). + * + * Note that, although unlikely, there is a risk that re-attaching domains might + * fail due to some unexpected happening like OOM. + */ +void pci_dev_reset_iommu_done(struct pci_dev *pdev) +{ + struct iommu_group *group = pdev->dev.iommu_group; + struct group_device *gdev; + unsigned long pasid; + void *entry; + + if (!pci_ats_supported(pdev) || !dev_has_iommu(&pdev->dev)) + return; + + guard(mutex)(&group->mutex); + + gdev = __dev_to_gdev(&pdev->dev); + if (WARN_ON(!gdev)) + return; + + /* Unbalanced done() calls would underflow the counter */ + if (WARN_ON(gdev->reset_depth == 0)) + return; + if (--gdev->reset_depth) + return; + + if (WARN_ON(!group->blocking_domain)) + return; + + if (group_device_dma_alias_is_blocked(group, gdev)) { + /* + * FIXME: DMA aliased devices share the same RID, which would be + * convoluted to handle, as "gdev->blocked" is not sufficient: + * - "blocked" state is effectively shared across these devices + * - if the core skipped the blocking on the second device, the + * IOMMU driver's attachment state would diverge from the HW + * state + * For now, just warn and see whether real ATS use cases hit it. + */ + pci_warn(pdev, + "DMA-aliased sibling may be prematurely unblocked\n"); + } + + /* + * Re-attach RID domain back to group->domain + * + * Leave the device parked in the blocking_domain if group->domain isn't + * initialized yet + */ + if (group->domain && group->domain != group->blocking_domain) { + WARN_ON(__iommu_attach_device(group->domain, &pdev->dev, + group->blocking_domain)); + } + + /* + * Update gdev->blocked upon the domain change, as it is used to return + * the correct domain in iommu_driver_get_domain_for_dev() that might be + * called in a set_dev_pasid callback function. + */ + gdev->blocked = false; + + /* + * Re-attach PASID domains back to the domains retained in pasid_array. + * + * The pasid_array is mostly fenced by group->mutex, except one reader + * in iommu_attach_handle_get(), so it's safe to read without xa_lock. + */ + if (pdev->dev.iommu->max_pasids > 0) { + xa_for_each_start(&group->pasid_array, pasid, entry, 1) { + struct iommu_domain *pasid_dom = + pasid_array_entry_to_domain(entry); + + WARN_ON(pasid_dom->ops->set_dev_pasid( + pasid_dom, &pdev->dev, pasid, + group->blocking_domain)); + } + } + + if (!WARN_ON(group->recovery_cnt == 0)) + group->recovery_cnt--; +} +EXPORT_SYMBOL_GPL(pci_dev_reset_iommu_done); + +#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU) +/** + * iommu_dma_prepare_msi() - Map the MSI page in the IOMMU domain + * @desc: MSI descriptor, will store the MSI page + * @msi_addr: MSI target address to be mapped + * + * The implementation of sw_msi() should take msi_addr and map it to + * an IOVA in the domain and call msi_desc_set_iommu_msi_iova() with the + * mapping information. + * + * Return: 0 on success or negative error code if the mapping failed. + */ +int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr) +{ + struct device *dev = msi_desc_to_dev(desc); + struct iommu_group *group = dev->iommu_group; + int ret = 0; + + if (!group) + return 0; + + mutex_lock(&group->mutex); + /* An IDENTITY domain must pass through */ + if (group->domain && group->domain->type != IOMMU_DOMAIN_IDENTITY) { + switch (group->domain->cookie_type) { + case IOMMU_COOKIE_DMA_MSI: + case IOMMU_COOKIE_DMA_IOVA: + ret = iommu_dma_sw_msi(group->domain, desc, msi_addr); + break; + case IOMMU_COOKIE_IOMMUFD: + ret = iommufd_sw_msi(group->domain, desc, msi_addr); + break; + default: + ret = -EOPNOTSUPP; + break; + } + } + mutex_unlock(&group->mutex); + return ret; +} +#endif /* CONFIG_IRQ_MSI_IOMMU */ |