diff options
Diffstat (limited to 'drivers/iommu/iommu.c')
| -rw-r--r-- | drivers/iommu/iommu.c | 3271 |
1 files changed, 3271 insertions, 0 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c new file mode 100644 index 000000000..8b3897239 --- /dev/null +++ b/drivers/iommu/iommu.c @@ -0,0 +1,3271 @@ +// 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/idr.h> +#include <linux/err.h> +#include <linux/pci.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 <trace/events/iommu.h> + +#include "dma-iommu.h" + +static struct kset *iommu_group_kset; +static DEFINE_IDA(iommu_group_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; + +struct iommu_group { + struct kobject kobj; + struct kobject *devices_kobj; + struct list_head devices; + 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; + void *owner; +}; + +struct group_device { + struct list_head list; + struct device *dev; + char *name; +}; + +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 iommu_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data); +static int iommu_alloc_default_domain(struct iommu_group *group, + struct device *dev); +static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, + unsigned type); +static int __iommu_attach_device(struct iommu_domain *domain, + struct device *dev); +static int __iommu_attach_group(struct iommu_domain *domain, + struct iommu_group *group); +static int __iommu_group_set_domain(struct iommu_group *group, + struct iommu_domain *new_domain); +static int iommu_create_device_direct_mappings(struct iommu_group *group, + struct device *dev); +static struct iommu_group *iommu_group_get_for_dev(struct device *dev); +static ssize_t iommu_group_store_type(struct iommu_group *group, + const char *buf, size_t count); + +#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 struct bus_type * const iommu_buses[] = { + &platform_bus_type, +#ifdef CONFIG_PCI + &pci_bus_type, +#endif +#ifdef CONFIG_ARM_AMBA + &amba_bustype, +#endif +#ifdef CONFIG_FSL_MC_BUS + &fsl_mc_bus_type, +#endif +#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS + &host1x_context_device_bus_type, +#endif +}; + +/* + * Use a function instead of an array here because the domain-type is a + * bit-field, so an array would waste memory. + */ +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"; + 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 = kcalloc(ARRAY_SIZE(iommu_buses), sizeof(*nb), GFP_KERNEL); + if (!nb) + return -ENOMEM; + + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) { + nb[i].notifier_call = iommu_bus_notifier; + bus_register_notifier(iommu_buses[i], &nb[i]); + } + + return 0; +} +subsys_initcall(iommu_subsys_init); + +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; + /* + * Temporarily enforce global restriction to a single driver. This was + * already the de-facto behaviour, since any possible combination of + * existing drivers would compete for at least the PCI or platform bus. + */ + if (iommu_buses[0]->iommu_ops && iommu_buses[0]->iommu_ops != ops) + return -EBUSY; + + iommu->ops = ops; + if (hwdev) + 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++) { + iommu_buses[i]->iommu_ops = ops; + err = bus_iommu_probe(iommu_buses[i]); + } + if (err) + iommu_device_unregister(iommu); + 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); +} +EXPORT_SYMBOL_GPL(iommu_device_unregister); + +static struct dev_iommu *dev_iommu_get(struct device *dev) +{ + struct dev_iommu *param = dev->iommu; + + if (param) + return param; + + param = kzalloc(sizeof(*param), GFP_KERNEL); + if (!param) + return NULL; + + mutex_init(¶m->lock); + dev->iommu = param; + return param; +} + +static 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); +} + +DEFINE_MUTEX(iommu_probe_device_lock); + +static int __iommu_probe_device(struct device *dev, struct list_head *group_list) +{ + const struct iommu_ops *ops = dev->bus->iommu_ops; + struct iommu_device *iommu_dev; + struct iommu_group *group; + int ret; + + if (!ops) + return -ENODEV; + /* + * 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); + if (!dev_iommu_get(dev)) + return -ENOMEM; + + 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 out_module_put; + } + + dev->iommu->iommu_dev = iommu_dev; + + group = iommu_group_get_for_dev(dev); + if (IS_ERR(group)) { + ret = PTR_ERR(group); + goto out_release; + } + + mutex_lock(&group->mutex); + if (group_list && !group->default_domain && list_empty(&group->entry)) + list_add_tail(&group->entry, group_list); + mutex_unlock(&group->mutex); + iommu_group_put(group); + + iommu_device_link(iommu_dev, dev); + + return 0; + +out_release: + if (ops->release_device) + ops->release_device(dev); + +out_module_put: + module_put(ops->owner); + +err_free: + dev_iommu_free(dev); + + return ret; +} + +int iommu_probe_device(struct device *dev) +{ + const struct iommu_ops *ops; + struct iommu_group *group; + int ret; + + mutex_lock(&iommu_probe_device_lock); + ret = __iommu_probe_device(dev, NULL); + mutex_unlock(&iommu_probe_device_lock); + if (ret) + goto err_out; + + group = iommu_group_get(dev); + if (!group) { + ret = -ENODEV; + goto err_release; + } + + /* + * Try to allocate a default domain - needs support from the + * IOMMU driver. There are still some drivers which don't + * support default domains, so the return value is not yet + * checked. + */ + mutex_lock(&group->mutex); + iommu_alloc_default_domain(group, dev); + + /* + * If device joined an existing group which has been claimed, don't + * attach the default domain. + */ + if (group->default_domain && !group->owner) { + ret = __iommu_attach_device(group->default_domain, dev); + if (ret) { + mutex_unlock(&group->mutex); + iommu_group_put(group); + goto err_release; + } + } + + iommu_create_device_direct_mappings(group, dev); + + mutex_unlock(&group->mutex); + iommu_group_put(group); + + ops = dev_iommu_ops(dev); + if (ops->probe_finalize) + ops->probe_finalize(dev); + + return 0; + +err_release: + iommu_release_device(dev); + +err_out: + return ret; + +} + +void iommu_release_device(struct device *dev) +{ + const struct iommu_ops *ops; + + if (!dev->iommu) + return; + + iommu_device_unlink(dev->iommu->iommu_dev, dev); + + ops = dev_iommu_ops(dev); + if (ops->release_device) + ops->release_device(dev); + + iommu_group_remove_device(dev); + module_put(ops->owner); + 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 sprintf(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); + list_for_each_entry(device, &group->devices, list) { + 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 (!device->dev->iommu) + 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; + char *str = buf; + + 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) { + str += sprintf(str, "0x%016llx 0x%016llx %s\n", + (long long int)region->start, + (long long int)(region->start + + region->length - 1), + iommu_group_resv_type_string[region->type]); + kfree(region); + } + + return (str - buf); +} + +static ssize_t iommu_group_show_type(struct iommu_group *group, + char *buf) +{ + char *type = "unknown\n"; + + mutex_lock(&group->mutex); + if (group->default_domain) { + switch (group->default_domain->type) { + case IOMMU_DOMAIN_BLOCKED: + type = "blocked\n"; + break; + case IOMMU_DOMAIN_IDENTITY: + type = "identity\n"; + break; + case IOMMU_DOMAIN_UNMANAGED: + type = "unmanaged\n"; + break; + case IOMMU_DOMAIN_DMA: + type = "DMA\n"; + break; + case IOMMU_DOMAIN_DMA_FQ: + type = "DMA-FQ\n"; + break; + } + } + mutex_unlock(&group->mutex); + strcpy(buf, type); + + return strlen(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); + + if (group->default_domain) + iommu_domain_free(group->default_domain); + if (group->blocking_domain) + iommu_domain_free(group->blocking_domain); + + kfree(group->name); + kfree(group); +} + +static 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(sizeof(*group), GFP_KERNEL); + 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); + + 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); + +struct iommu_group *iommu_group_get_by_id(int id) +{ + struct kobject *group_kobj; + struct iommu_group *group; + const char *name; + + if (!iommu_group_kset) + return NULL; + + name = kasprintf(GFP_KERNEL, "%d", id); + if (!name) + return NULL; + + group_kobj = kset_find_obj(iommu_group_kset, name); + kfree(name); + + if (!group_kobj) + return NULL; + + group = container_of(group_kobj, struct iommu_group, kobj); + BUG_ON(group->id != id); + + kobject_get(group->devices_kobj); + kobject_put(&group->kobj); + + return group; +} +EXPORT_SYMBOL_GPL(iommu_group_get_by_id); + +/** + * 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_group *group, + struct device *dev) +{ + struct iommu_domain *domain = group->default_domain; + struct iommu_resv_region *entry; + struct list_head mappings; + unsigned long pg_size; + int ret = 0; + + if (!domain || !iommu_is_dma_domain(domain)) + return 0; + + BUG_ON(!domain->pgsize_bitmap); + + pg_size = 1UL << __ffs(domain->pgsize_bitmap); + INIT_LIST_HEAD(&mappings); + + 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; + + start = ALIGN(entry->start, pg_size); + end = ALIGN(entry->start + entry->length, pg_size); + + if (entry->type != IOMMU_RESV_DIRECT && + entry->type != IOMMU_RESV_DIRECT_RELAXABLE) + continue; + + for (addr = start; addr <= end; addr += pg_size) { + phys_addr_t phys_addr; + + if (addr == end) + goto map_end; + + phys_addr = iommu_iova_to_phys(domain, addr); + 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); + if (ret) + goto out; + map_size = 0; + } + } + + } + + iommu_flush_iotlb_all(domain); + +out: + iommu_put_resv_regions(dev, &mappings); + + return ret; +} + +static bool iommu_is_attach_deferred(struct device *dev) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + + if (ops->is_attach_deferred) + return ops->is_attach_deferred(dev); + + return false; +} + +/** + * 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) +{ + int ret, i = 0; + struct group_device *device; + + device = kzalloc(sizeof(*device), GFP_KERNEL); + if (!device) + return -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; + } + + kobject_get(group->devices_kobj); + + dev->iommu_group = group; + + mutex_lock(&group->mutex); + list_add_tail(&device->list, &group->devices); + if (group->domain && !iommu_is_attach_deferred(dev)) + ret = __iommu_attach_device(group->domain, dev); + mutex_unlock(&group->mutex); + if (ret) + goto err_put_group; + + trace_add_device_to_group(group->id, dev); + + dev_info(dev, "Adding to iommu group %d\n", group->id); + + return 0; + +err_put_group: + mutex_lock(&group->mutex); + list_del(&device->list); + mutex_unlock(&group->mutex); + dev->iommu_group = NULL; + kobject_put(group->devices_kobj); + sysfs_remove_link(group->devices_kobj, device->name); +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 ret; +} +EXPORT_SYMBOL_GPL(iommu_group_add_device); + +/** + * iommu_group_remove_device - remove a device from it's current group + * @dev: device to be removed + * + * This function is called by an iommu driver to remove the device from + * it's current group. This decrements the iommu group reference count. + */ +void iommu_group_remove_device(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + struct group_device *tmp_device, *device = NULL; + + if (!group) + return; + + dev_info(dev, "Removing from iommu group %d\n", group->id); + + mutex_lock(&group->mutex); + list_for_each_entry(tmp_device, &group->devices, list) { + if (tmp_device->dev == dev) { + device = tmp_device; + list_del(&device->list); + break; + } + } + mutex_unlock(&group->mutex); + + if (!device) + return; + + sysfs_remove_link(group->devices_kobj, device->name); + sysfs_remove_link(&dev->kobj, "iommu_group"); + + trace_remove_device_from_group(group->id, dev); + + kfree(device->name); + kfree(device); + dev->iommu_group = NULL; + kobject_put(group->devices_kobj); +} +EXPORT_SYMBOL_GPL(iommu_group_remove_device); + +static int iommu_group_device_count(struct iommu_group *group) +{ + struct group_device *entry; + int ret = 0; + + list_for_each_entry(entry, &group->devices, list) + ret++; + + return ret; +} + +static int __iommu_group_for_each_dev(struct iommu_group *group, void *data, + int (*fn)(struct device *, void *)) +{ + struct group_device *device; + int ret = 0; + + list_for_each_entry(device, &group->devices, list) { + ret = fn(device->dev, data); + if (ret) + break; + } + return ret; +} + +/** + * 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 *)) +{ + int ret; + + mutex_lock(&group->mutex); + ret = __iommu_group_for_each_dev(group, data, fn); + 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_register_device_fault_handler() - Register a device fault handler + * @dev: the device + * @handler: the fault handler + * @data: private data passed as argument to the handler + * + * When an IOMMU fault event is received, this handler gets called with the + * fault event and data as argument. The handler should return 0 on success. If + * the fault is recoverable (IOMMU_FAULT_PAGE_REQ), the consumer should also + * complete the fault by calling iommu_page_response() with one of the following + * response code: + * - IOMMU_PAGE_RESP_SUCCESS: retry the translation + * - IOMMU_PAGE_RESP_INVALID: terminate the fault + * - IOMMU_PAGE_RESP_FAILURE: terminate the fault and stop reporting + * page faults if possible. + * + * Return 0 if the fault handler was installed successfully, or an error. + */ +int iommu_register_device_fault_handler(struct device *dev, + iommu_dev_fault_handler_t handler, + void *data) +{ + struct dev_iommu *param = dev->iommu; + int ret = 0; + + if (!param) + return -EINVAL; + + mutex_lock(¶m->lock); + /* Only allow one fault handler registered for each device */ + if (param->fault_param) { + ret = -EBUSY; + goto done_unlock; + } + + get_device(dev); + param->fault_param = kzalloc(sizeof(*param->fault_param), GFP_KERNEL); + if (!param->fault_param) { + put_device(dev); + ret = -ENOMEM; + goto done_unlock; + } + param->fault_param->handler = handler; + param->fault_param->data = data; + mutex_init(¶m->fault_param->lock); + INIT_LIST_HEAD(¶m->fault_param->faults); + +done_unlock: + mutex_unlock(¶m->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_register_device_fault_handler); + +/** + * iommu_unregister_device_fault_handler() - Unregister the device fault handler + * @dev: the device + * + * Remove the device fault handler installed with + * iommu_register_device_fault_handler(). + * + * Return 0 on success, or an error. + */ +int iommu_unregister_device_fault_handler(struct device *dev) +{ + struct dev_iommu *param = dev->iommu; + int ret = 0; + + if (!param) + return -EINVAL; + + mutex_lock(¶m->lock); + + if (!param->fault_param) + goto unlock; + + /* we cannot unregister handler if there are pending faults */ + if (!list_empty(¶m->fault_param->faults)) { + ret = -EBUSY; + goto unlock; + } + + kfree(param->fault_param); + param->fault_param = NULL; + put_device(dev); +unlock: + mutex_unlock(¶m->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_unregister_device_fault_handler); + +/** + * iommu_report_device_fault() - Report fault event to device driver + * @dev: the device + * @evt: fault event data + * + * Called by IOMMU drivers when a fault is detected, typically in a threaded IRQ + * handler. When this function fails and the fault is recoverable, it is the + * caller's responsibility to complete the fault. + * + * Return 0 on success, or an error. + */ +int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt) +{ + struct dev_iommu *param = dev->iommu; + struct iommu_fault_event *evt_pending = NULL; + struct iommu_fault_param *fparam; + int ret = 0; + + if (!param || !evt) + return -EINVAL; + + /* we only report device fault if there is a handler registered */ + mutex_lock(¶m->lock); + fparam = param->fault_param; + if (!fparam || !fparam->handler) { + ret = -EINVAL; + goto done_unlock; + } + + if (evt->fault.type == IOMMU_FAULT_PAGE_REQ && + (evt->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) { + evt_pending = kmemdup(evt, sizeof(struct iommu_fault_event), + GFP_KERNEL); + if (!evt_pending) { + ret = -ENOMEM; + goto done_unlock; + } + mutex_lock(&fparam->lock); + list_add_tail(&evt_pending->list, &fparam->faults); + mutex_unlock(&fparam->lock); + } + + ret = fparam->handler(&evt->fault, fparam->data); + if (ret && evt_pending) { + mutex_lock(&fparam->lock); + list_del(&evt_pending->list); + mutex_unlock(&fparam->lock); + kfree(evt_pending); + } +done_unlock: + mutex_unlock(¶m->lock); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_report_device_fault); + +int iommu_page_response(struct device *dev, + struct iommu_page_response *msg) +{ + bool needs_pasid; + int ret = -EINVAL; + struct iommu_fault_event *evt; + struct iommu_fault_page_request *prm; + struct dev_iommu *param = dev->iommu; + const struct iommu_ops *ops = dev_iommu_ops(dev); + bool has_pasid = msg->flags & IOMMU_PAGE_RESP_PASID_VALID; + + if (!ops->page_response) + return -ENODEV; + + if (!param || !param->fault_param) + return -EINVAL; + + if (msg->version != IOMMU_PAGE_RESP_VERSION_1 || + msg->flags & ~IOMMU_PAGE_RESP_PASID_VALID) + return -EINVAL; + + /* Only send response if there is a fault report pending */ + mutex_lock(¶m->fault_param->lock); + if (list_empty(¶m->fault_param->faults)) { + dev_warn_ratelimited(dev, "no pending PRQ, drop response\n"); + goto done_unlock; + } + /* + * Check if we have a matching page request pending to respond, + * otherwise return -EINVAL + */ + list_for_each_entry(evt, ¶m->fault_param->faults, list) { + prm = &evt->fault.prm; + if (prm->grpid != msg->grpid) + continue; + + /* + * If the PASID is required, the corresponding request is + * matched using the group ID, the PASID valid bit and the PASID + * value. Otherwise only the group ID matches request and + * response. + */ + needs_pasid = prm->flags & IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID; + if (needs_pasid && (!has_pasid || msg->pasid != prm->pasid)) + continue; + + if (!needs_pasid && has_pasid) { + /* No big deal, just clear it. */ + msg->flags &= ~IOMMU_PAGE_RESP_PASID_VALID; + msg->pasid = 0; + } + + ret = ops->page_response(dev, evt, msg); + list_del(&evt->list); + kfree(evt); + break; + } + +done_unlock: + mutex_unlock(¶m->fault_param->lock); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_page_response); + +/** + * 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); + +/* + * 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 int iommu_get_def_domain_type(struct device *dev) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + + if (dev_is_pci(dev) && to_pci_dev(dev)->untrusted) + return IOMMU_DOMAIN_DMA; + + if (ops->def_domain_type) + return ops->def_domain_type(dev); + + return 0; +} + +static int iommu_group_alloc_default_domain(struct bus_type *bus, + struct iommu_group *group, + unsigned int type) +{ + struct iommu_domain *dom; + + dom = __iommu_domain_alloc(bus, type); + if (!dom && type != IOMMU_DOMAIN_DMA) { + dom = __iommu_domain_alloc(bus, IOMMU_DOMAIN_DMA); + if (dom) + pr_warn("Failed to allocate default IOMMU domain of type %u for group %s - Falling back to IOMMU_DOMAIN_DMA", + type, group->name); + } + + if (!dom) + return -ENOMEM; + + group->default_domain = dom; + if (!group->domain) + group->domain = dom; + return 0; +} + +static int iommu_alloc_default_domain(struct iommu_group *group, + struct device *dev) +{ + unsigned int type; + + if (group->default_domain) + return 0; + + type = iommu_get_def_domain_type(dev) ? : iommu_def_domain_type; + + return iommu_group_alloc_default_domain(dev->bus, group, type); +} + +/** + * iommu_group_get_for_dev - Find or create the IOMMU group for a device + * @dev: target device + * + * This function is intended to be called by IOMMU drivers and extended to + * support common, bus-defined algorithms when determining or creating the + * IOMMU group for a device. On success, the caller will hold a reference + * to the returned IOMMU group, which will already include the provided + * device. The reference should be released with iommu_group_put(). + */ +static struct iommu_group *iommu_group_get_for_dev(struct device *dev) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + struct iommu_group *group; + int ret; + + group = iommu_group_get(dev); + if (group) + return group; + + group = ops->device_group(dev); + if (WARN_ON_ONCE(group == NULL)) + return ERR_PTR(-EINVAL); + + if (IS_ERR(group)) + return group; + + ret = iommu_group_add_device(group, dev); + if (ret) + goto out_put_group; + + return group; + +out_put_group: + iommu_group_put(group); + + return ERR_PTR(ret); +} + +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; + struct iommu_group *group; + int ret; + + /* Device is probed already if in a group */ + group = iommu_group_get(dev); + if (group) { + iommu_group_put(group); + return 0; + } + + 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; +} + +struct __group_domain_type { + struct device *dev; + unsigned int type; +}; + +static int probe_get_default_domain_type(struct device *dev, void *data) +{ + struct __group_domain_type *gtype = data; + unsigned int type = iommu_get_def_domain_type(dev); + + if (type) { + if (gtype->type && gtype->type != type) { + dev_warn(dev, "Device needs domain type %s, but device %s in the same iommu group requires type %s - using default\n", + iommu_domain_type_str(type), + dev_name(gtype->dev), + iommu_domain_type_str(gtype->type)); + gtype->type = 0; + } + + if (!gtype->dev) { + gtype->dev = dev; + gtype->type = type; + } + } + + return 0; +} + +static void probe_alloc_default_domain(struct bus_type *bus, + struct iommu_group *group) +{ + struct __group_domain_type gtype; + + memset(>ype, 0, sizeof(gtype)); + + /* Ask for default domain requirements of all devices in the group */ + __iommu_group_for_each_dev(group, >ype, + probe_get_default_domain_type); + + if (!gtype.type) + gtype.type = iommu_def_domain_type; + + iommu_group_alloc_default_domain(bus, group, gtype.type); + +} + +static int iommu_group_do_dma_attach(struct device *dev, void *data) +{ + struct iommu_domain *domain = data; + int ret = 0; + + if (!iommu_is_attach_deferred(dev)) + ret = __iommu_attach_device(domain, dev); + + return ret; +} + +static int __iommu_group_dma_attach(struct iommu_group *group) +{ + return __iommu_group_for_each_dev(group, group->default_domain, + iommu_group_do_dma_attach); +} + +static int iommu_group_do_probe_finalize(struct device *dev, void *data) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + + if (ops->probe_finalize) + ops->probe_finalize(dev); + + return 0; +} + +static void __iommu_group_dma_finalize(struct iommu_group *group) +{ + __iommu_group_for_each_dev(group, group->default_domain, + iommu_group_do_probe_finalize); +} + +static int iommu_do_create_direct_mappings(struct device *dev, void *data) +{ + struct iommu_group *group = data; + + iommu_create_device_direct_mappings(group, dev); + + return 0; +} + +static int iommu_group_create_direct_mappings(struct iommu_group *group) +{ + return __iommu_group_for_each_dev(group, group, + iommu_do_create_direct_mappings); +} + +int bus_iommu_probe(struct bus_type *bus) +{ + struct iommu_group *group, *next; + LIST_HEAD(group_list); + int ret; + + /* + * This code-path does not allocate the default domain when + * creating the iommu group, so do it after the groups are + * created. + */ + 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) { + mutex_lock(&group->mutex); + + /* Remove item from the list */ + list_del_init(&group->entry); + + /* Try to allocate default domain */ + probe_alloc_default_domain(bus, group); + + if (!group->default_domain) { + mutex_unlock(&group->mutex); + continue; + } + + iommu_group_create_direct_mappings(group); + + ret = __iommu_group_dma_attach(group); + + mutex_unlock(&group->mutex); + + if (ret) + break; + + __iommu_group_dma_finalize(group); + } + + return ret; +} + +bool iommu_present(struct bus_type *bus) +{ + return bus->iommu_ops != NULL; +} +EXPORT_SYMBOL_GPL(iommu_present); + +/** + * 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->iommu || !dev->iommu->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_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) +{ + BUG_ON(!domain); + + domain->handler = handler; + domain->handler_token = token; +} +EXPORT_SYMBOL_GPL(iommu_set_fault_handler); + +static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, + unsigned type) +{ + struct iommu_domain *domain; + + if (bus == NULL || bus->iommu_ops == NULL) + return NULL; + + domain = bus->iommu_ops->domain_alloc(type); + if (!domain) + return NULL; + + domain->type = type; + /* + * If not already set, assume all sizes by default; the driver + * may override this later + */ + if (!domain->pgsize_bitmap) + domain->pgsize_bitmap = bus->iommu_ops->pgsize_bitmap; + + if (!domain->ops) + domain->ops = bus->iommu_ops->default_domain_ops; + + if (iommu_is_dma_domain(domain) && iommu_get_dma_cookie(domain)) { + iommu_domain_free(domain); + domain = NULL; + } + return domain; +} + +struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) +{ + return __iommu_domain_alloc(bus, IOMMU_DOMAIN_UNMANAGED); +} +EXPORT_SYMBOL_GPL(iommu_domain_alloc); + +void iommu_domain_free(struct iommu_domain *domain) +{ + iommu_put_dma_cookie(domain); + 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; + int ret; + + if (group->owner) + new_domain = group->blocking_domain; + else + new_domain = group->default_domain; + + ret = __iommu_group_set_domain(group, new_domain); + WARN(ret, "iommu driver failed to attach the default/blocking domain"); +} + +static int __iommu_attach_device(struct iommu_domain *domain, + struct device *dev) +{ + int ret; + + if (unlikely(domain->ops->attach_dev == NULL)) + return -ENODEV; + + ret = domain->ops->attach_dev(domain, dev); + if (!ret) + trace_attach_device_to_domain(dev); + return ret; +} + +int iommu_attach_device(struct iommu_domain *domain, struct device *dev) +{ + struct iommu_group *group; + int ret; + + group = iommu_group_get(dev); + 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 (iommu_group_device_count(group) != 1) + goto out_unlock; + + ret = __iommu_attach_group(domain, group); + +out_unlock: + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_attach_device); + +int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain) +{ + if (iommu_is_attach_deferred(dev)) + return __iommu_attach_device(domain, dev); + + return 0; +} + +static void __iommu_detach_device(struct iommu_domain *domain, + struct device *dev) +{ + if (iommu_is_attach_deferred(dev)) + return; + + domain->ops->detach_dev(domain, dev); + trace_detach_device_from_domain(dev); +} + +void iommu_detach_device(struct iommu_domain *domain, struct device *dev) +{ + struct iommu_group *group; + + group = iommu_group_get(dev); + if (!group) + return; + + mutex_lock(&group->mutex); + if (WARN_ON(domain != group->domain) || + WARN_ON(iommu_group_device_count(group) != 1)) + goto out_unlock; + __iommu_group_set_core_domain(group); + +out_unlock: + mutex_unlock(&group->mutex); + iommu_group_put(group); +} +EXPORT_SYMBOL_GPL(iommu_detach_device); + +struct iommu_domain *iommu_get_domain_for_dev(struct device *dev) +{ + struct iommu_domain *domain; + struct iommu_group *group; + + group = iommu_group_get(dev); + if (!group) + return NULL; + + domain = group->domain; + + iommu_group_put(group); + + return domain; +} +EXPORT_SYMBOL_GPL(iommu_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; +} + +/* + * 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_do_attach_device(struct device *dev, void *data) +{ + struct iommu_domain *domain = data; + + return __iommu_attach_device(domain, dev); +} + +static int __iommu_attach_group(struct iommu_domain *domain, + struct iommu_group *group) +{ + int ret; + + if (group->domain && group->domain != group->default_domain && + group->domain != group->blocking_domain) + return -EBUSY; + + ret = __iommu_group_for_each_dev(group, domain, + iommu_group_do_attach_device); + if (ret == 0) { + group->domain = domain; + } else { + /* + * To recover from the case when certain device within the + * group fails to attach to the new domain, we need force + * attaching all devices back to the old domain. The old + * domain is compatible for all devices in the group, + * hence the iommu driver should always return success. + */ + struct iommu_domain *old_domain = group->domain; + + group->domain = NULL; + WARN(__iommu_group_set_domain(group, old_domain), + "iommu driver failed to attach a compatible domain"); + } + + return ret; +} + +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_group_do_detach_device(struct device *dev, void *data) +{ + struct iommu_domain *domain = data; + + __iommu_detach_device(domain, dev); + + return 0; +} + +static int __iommu_group_set_domain(struct iommu_group *group, + struct iommu_domain *new_domain) +{ + int ret; + + if (group->domain == new_domain) + return 0; + + /* + * New drivers should support default domains and so the detach_dev() op + * will never be called. Otherwise the NULL domain represents some + * platform specific behavior. + */ + if (!new_domain) { + if (WARN_ON(!group->domain->ops->detach_dev)) + return -EINVAL; + __iommu_group_for_each_dev(group, group->domain, + iommu_group_do_detach_device); + group->domain = NULL; + return 0; + } + + /* + * 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. + * + * Note that this is called in error unwind paths, attaching to a + * domain that has already been attached cannot fail. + */ + ret = __iommu_group_for_each_dev(group, new_domain, + iommu_group_do_attach_device); + if (ret) + return ret; + group->domain = new_domain; + return 0; +} + +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; + 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 (offset + pgsize_next <= size) + size = offset; + +out_set_count: + *count = size >> pgsize_idx; + return pgsize; +} + +static int __iommu_map_pages(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; + size_t pgsize, count; + int ret; + + 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); + + if (ops->map_pages) { + ret = ops->map_pages(domain, iova, paddr, pgsize, count, prot, + gfp, mapped); + } else { + ret = ops->map(domain, iova, paddr, pgsize, prot, gfp); + *mapped = ret ? 0 : pgsize; + } + + return ret; +} + +static int __iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) +{ + const struct iommu_domain_ops *ops = domain->ops; + unsigned long orig_iova = iova; + unsigned int min_pagesz; + size_t orig_size = size; + phys_addr_t orig_paddr = paddr; + int ret = 0; + + if (unlikely(!(ops->map || ops->map_pages) || + domain->pgsize_bitmap == 0UL)) + return -ENODEV; + + if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING))) + return -EINVAL; + + /* 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 mapped = 0; + + ret = __iommu_map_pages(domain, iova, paddr, size, prot, gfp, + &mapped); + /* + * Some pages may have been mapped, even if an error occurred, + * so we should account for those so they can be unmapped. + */ + size -= mapped; + + if (ret) + break; + + iova += mapped; + paddr += mapped; + } + + /* unroll mapping in case something went wrong */ + if (ret) + iommu_unmap(domain, orig_iova, orig_size - size); + else + trace_map(orig_iova, orig_paddr, orig_size); + + return ret; +} + +static int _iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) +{ + const struct iommu_domain_ops *ops = domain->ops; + int ret; + + ret = __iommu_map(domain, iova, paddr, size, prot, gfp); + if (ret == 0 && ops->iotlb_sync_map) + ops->iotlb_sync_map(domain, iova, size); + + return ret; +} + +int iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot) +{ + might_sleep(); + return _iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL); +} +EXPORT_SYMBOL_GPL(iommu_map); + +int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot) +{ + return _iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC); +} +EXPORT_SYMBOL_GPL(iommu_map_atomic); + +static size_t __iommu_unmap_pages(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 pgsize, count; + + pgsize = iommu_pgsize(domain, iova, iova, size, &count); + return ops->unmap_pages ? + ops->unmap_pages(domain, iova, pgsize, count, iotlb_gather) : + ops->unmap(domain, iova, pgsize, iotlb_gather); +} + +static size_t __iommu_unmap(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 long orig_iova = iova; + unsigned int min_pagesz; + + if (unlikely(!(ops->unmap || ops->unmap_pages) || + domain->pgsize_bitmap == 0UL)) + return 0; + + if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING))) + 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) { + unmapped_page = __iommu_unmap_pages(domain, iova, + size - unmapped, + iotlb_gather); + if (!unmapped_page) + break; + + pr_debug("unmapped: iova 0x%lx size 0x%zx\n", + iova, unmapped_page); + + iova += unmapped_page; + unmapped += unmapped_page; + } + + trace_unmap(orig_iova, size, unmapped); + return unmapped; +} + +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); + +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); + +static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot, + gfp_t gfp) +{ + const struct iommu_domain_ops *ops = domain->ops; + 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(domain, iova + mapped, start, + len, prot, gfp); + + if (ret) + goto out_err; + + mapped += len; + len = 0; + } + + if (sg_is_dma_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); + } + + if (ops->iotlb_sync_map) + ops->iotlb_sync_map(domain, iova, mapped); + return mapped; + +out_err: + /* undo mappings already done */ + iommu_unmap(domain, iova, mapped); + + return ret; +} + +ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot) +{ + might_sleep(); + return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_KERNEL); +} +EXPORT_SYMBOL_GPL(iommu_map_sg); + +ssize_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot) +{ + return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC); +} + +/** + * 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->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_enable_nesting(struct iommu_domain *domain) +{ + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -EINVAL; + if (!domain->ops->enable_nesting) + return -EINVAL; + return domain->ops->enable_nesting(domain); +} +EXPORT_SYMBOL_GPL(iommu_enable_nesting); + +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); + +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); +} + +/** + * iommu_put_resv_regions - release resered 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(sizeof(*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); + +const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) +{ + const struct iommu_ops *ops = NULL; + struct iommu_device *iommu; + + spin_lock(&iommu_device_lock); + list_for_each_entry(iommu, &iommu_device_list, list) + if (iommu->fwnode == fwnode) { + ops = iommu->ops; + break; + } + spin_unlock(&iommu_device_lock); + return ops; +} + +int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, + const struct iommu_ops *ops) +{ + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + + if (fwspec) + return ops == fwspec->ops ? 0 : -EINVAL; + + if (!dev_iommu_get(dev)) + return -ENOMEM; + + /* Preallocate for the overwhelmingly common case of 1 ID */ + fwspec = kzalloc(struct_size(fwspec, ids, 1), GFP_KERNEL); + if (!fwspec) + return -ENOMEM; + + of_node_get(to_of_node(iommu_fwnode)); + fwspec->iommu_fwnode = iommu_fwnode; + fwspec->ops = ops; + 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); + } +} +EXPORT_SYMBOL_GPL(iommu_fwspec_free); + +int iommu_fwspec_add_ids(struct device *dev, 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); + +/* + * Per device IOMMU features. + */ +int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat) +{ + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; + + if (ops->dev_enable_feat) + return ops->dev_enable_feat(dev, feat); + } + + return -ENODEV; +} +EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); + +/* + * The device drivers should do the necessary cleanups before calling this. + */ +int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) +{ + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; + + if (ops->dev_disable_feat) + return ops->dev_disable_feat(dev, feat); + } + + return -EBUSY; +} +EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); + +/** + * iommu_sva_bind_device() - Bind a process address space to a device + * @dev: the device + * @mm: the mm to bind, caller must hold a reference to it + * @drvdata: opaque data pointer to pass to bind callback + * + * Create a bond between device and address space, allowing the device to access + * the mm using the returned PASID. If a bond already exists between @device and + * @mm, it is returned and an additional reference is taken. Caller must call + * iommu_sva_unbind_device() to release each reference. + * + * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to + * initialize the required SVA features. + * + * On error, returns an ERR_PTR value. + */ +struct iommu_sva * +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) +{ + struct iommu_group *group; + struct iommu_sva *handle = ERR_PTR(-EINVAL); + const struct iommu_ops *ops = dev_iommu_ops(dev); + + if (!ops->sva_bind) + return ERR_PTR(-ENODEV); + + group = iommu_group_get(dev); + if (!group) + return ERR_PTR(-ENODEV); + + /* Ensure device count and domain don't change while we're binding */ + mutex_lock(&group->mutex); + + /* + * To keep things simple, SVA currently doesn't support IOMMU groups + * with more than one device. Existing SVA-capable systems are not + * affected by the problems that required IOMMU groups (lack of ACS + * isolation, device ID aliasing and other hardware issues). + */ + if (iommu_group_device_count(group) != 1) + goto out_unlock; + + handle = ops->sva_bind(dev, mm, drvdata); + +out_unlock: + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return handle; +} +EXPORT_SYMBOL_GPL(iommu_sva_bind_device); + +/** + * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device + * @handle: the handle returned by iommu_sva_bind_device() + * + * Put reference to a bond between device and address space. The device should + * not be issuing any more transaction for this PASID. All outstanding page + * requests for this PASID must have been flushed to the IOMMU. + */ +void iommu_sva_unbind_device(struct iommu_sva *handle) +{ + struct iommu_group *group; + struct device *dev = handle->dev; + const struct iommu_ops *ops = dev_iommu_ops(dev); + + if (!ops->sva_unbind) + return; + + group = iommu_group_get(dev); + if (!group) + return; + + mutex_lock(&group->mutex); + ops->sva_unbind(handle); + mutex_unlock(&group->mutex); + + iommu_group_put(group); +} +EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); + +u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + const struct iommu_ops *ops = dev_iommu_ops(handle->dev); + + if (!ops->sva_get_pasid) + return IOMMU_PASID_INVALID; + + return ops->sva_get_pasid(handle); +} +EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); + +/* + * Changes the default domain of an iommu group that has *only* one device + * + * @group: The group for which the default domain should be changed + * @prev_dev: The device in the group (this is used to make sure that the device + * hasn't changed after the caller has called this function) + * @type: The type of the new default domain that gets associated with the group + * + * Returns 0 on success and error code on failure + * + * Note: + * 1. Presently, this function is called only when user requests to change the + * group's default domain type through /sys/kernel/iommu_groups/<grp_id>/type + * Please take a closer look if intended to use for other purposes. + */ +static int iommu_change_dev_def_domain(struct iommu_group *group, + struct device *prev_dev, int type) +{ + struct iommu_domain *prev_dom; + struct group_device *grp_dev; + int ret, dev_def_dom; + struct device *dev; + + mutex_lock(&group->mutex); + + if (group->default_domain != group->domain) { + dev_err_ratelimited(prev_dev, "Group not assigned to default domain\n"); + ret = -EBUSY; + goto out; + } + + /* + * iommu group wasn't locked while acquiring device lock in + * iommu_group_store_type(). So, make sure that the device count hasn't + * changed while acquiring device lock. + * + * Changing default domain of an iommu group with two or more devices + * isn't supported because there could be a potential deadlock. Consider + * the following scenario. T1 is trying to acquire device locks of all + * the devices in the group and before it could acquire all of them, + * there could be another thread T2 (from different sub-system and use + * case) that has already acquired some of the device locks and might be + * waiting for T1 to release other device locks. + */ + if (iommu_group_device_count(group) != 1) { + dev_err_ratelimited(prev_dev, "Cannot change default domain: Group has more than one device\n"); + ret = -EINVAL; + goto out; + } + + /* Since group has only one device */ + grp_dev = list_first_entry(&group->devices, struct group_device, list); + dev = grp_dev->dev; + + if (prev_dev != dev) { + dev_err_ratelimited(prev_dev, "Cannot change default domain: Device has been changed\n"); + ret = -EBUSY; + goto out; + } + + prev_dom = group->default_domain; + if (!prev_dom) { + ret = -EINVAL; + goto out; + } + + dev_def_dom = iommu_get_def_domain_type(dev); + if (!type) { + /* + * If the user hasn't requested any specific type of domain and + * if the device supports both the domains, then default to the + * domain the device was booted with + */ + type = dev_def_dom ? : iommu_def_domain_type; + } else if (dev_def_dom && type != dev_def_dom) { + dev_err_ratelimited(prev_dev, "Device cannot be in %s domain\n", + iommu_domain_type_str(type)); + ret = -EINVAL; + goto out; + } + + /* + * Switch to a new domain only if the requested domain type is different + * from the existing default domain type + */ + if (prev_dom->type == type) { + ret = 0; + goto out; + } + + /* We can bring up a flush queue without tearing down the domain */ + if (type == IOMMU_DOMAIN_DMA_FQ && prev_dom->type == IOMMU_DOMAIN_DMA) { + ret = iommu_dma_init_fq(prev_dom); + if (!ret) + prev_dom->type = IOMMU_DOMAIN_DMA_FQ; + goto out; + } + + /* Sets group->default_domain to the newly allocated domain */ + ret = iommu_group_alloc_default_domain(dev->bus, group, type); + if (ret) + goto out; + + ret = iommu_create_device_direct_mappings(group, dev); + if (ret) + goto free_new_domain; + + ret = __iommu_attach_device(group->default_domain, dev); + if (ret) + goto free_new_domain; + + group->domain = group->default_domain; + + /* + * Release the mutex here because ops->probe_finalize() call-back of + * some vendor 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. + */ + mutex_unlock(&group->mutex); + + /* Make sure dma_ops is appropriatley set */ + iommu_group_do_probe_finalize(dev, group->default_domain); + iommu_domain_free(prev_dom); + return 0; + +free_new_domain: + iommu_domain_free(group->default_domain); + group->default_domain = prev_dom; + group->domain = prev_dom; + +out: + mutex_unlock(&group->mutex); + + 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. + * device_lock(dev) 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 *grp_dev; + struct device *dev; + 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; + + /* + * Lock/Unlock the group mutex here before device lock to + * 1. Make sure that the iommu group has only one device (this is a + * prerequisite for step 2) + * 2. Get struct *dev which is needed to lock device + */ + mutex_lock(&group->mutex); + if (iommu_group_device_count(group) != 1) { + mutex_unlock(&group->mutex); + pr_err_ratelimited("Cannot change default domain: Group has more than one device\n"); + return -EINVAL; + } + + /* Since group has only one device */ + grp_dev = list_first_entry(&group->devices, struct group_device, list); + dev = grp_dev->dev; + get_device(dev); + + /* + * Don't hold the group mutex because taking group mutex first and then + * the device lock could potentially cause a deadlock as below. Assume + * two threads T1 and T2. T1 is trying to change default domain of an + * iommu group and T2 is trying to hot unplug a device or release [1] VF + * of a PCIe device which is in the same iommu group. T1 takes group + * mutex and before it could take device lock assume T2 has taken device + * lock and is yet to take group mutex. Now, both the threads will be + * waiting for the other thread to release lock. Below, lock order was + * suggested. + * device_lock(dev); + * mutex_lock(&group->mutex); + * iommu_change_dev_def_domain(); + * mutex_unlock(&group->mutex); + * device_unlock(dev); + * + * [1] Typical device release path + * device_lock() from device/driver core code + * -> bus_notifier() + * -> iommu_bus_notifier() + * -> iommu_release_device() + * -> ops->release_device() vendor driver calls back iommu core code + * -> mutex_lock() from iommu core code + */ + mutex_unlock(&group->mutex); + + /* Check if the device in the group still has a driver bound to it */ + device_lock(dev); + if (device_is_bound(dev) && !(req_type == IOMMU_DOMAIN_DMA_FQ && + group->default_domain->type == IOMMU_DOMAIN_DMA)) { + pr_err_ratelimited("Device is still bound to driver\n"); + ret = -EBUSY; + goto out; + } + + ret = iommu_change_dev_def_domain(group, dev, req_type); + ret = ret ?: count; + +out: + device_unlock(dev); + put_device(dev); + + return ret; +} + +static bool iommu_is_default_domain(struct iommu_group *group) +{ + if (group->domain == group->default_domain) + return true; + + /* + * If the default domain was set to identity and it is still an identity + * domain then we consider this a pass. This happens because of + * amd_iommu_init_device() replacing the default idenytity domain with an + * identity domain that has a different configuration for AMDGPU. + */ + if (group->default_domain && + group->default_domain->type == IOMMU_DOMAIN_IDENTITY && + group->domain && group->domain->type == IOMMU_DOMAIN_IDENTITY) + return true; + return false; +} + +/** + * 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) +{ + struct iommu_group *group = iommu_group_get(dev); + int ret = 0; + + if (!group) + return 0; + + mutex_lock(&group->mutex); + if (group->owner_cnt) { + if (group->owner || !iommu_is_default_domain(group)) { + ret = -EBUSY; + goto unlock_out; + } + } + + group->owner_cnt++; + +unlock_out: + mutex_unlock(&group->mutex); + iommu_group_put(group); + + 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) +{ + struct iommu_group *group = iommu_group_get(dev); + + if (!group) + return; + + mutex_lock(&group->mutex); + if (!WARN_ON(!group->owner_cnt)) + group->owner_cnt--; + + mutex_unlock(&group->mutex); + iommu_group_put(group); +} + +static int __iommu_group_alloc_blocking_domain(struct iommu_group *group) +{ + struct group_device *dev = + list_first_entry(&group->devices, struct group_device, list); + + if (group->blocking_domain) + return 0; + + group->blocking_domain = + __iommu_domain_alloc(dev->dev->bus, IOMMU_DOMAIN_BLOCKED); + if (!group->blocking_domain) { + /* + * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED + * create an empty domain instead. + */ + group->blocking_domain = __iommu_domain_alloc( + dev->dev->bus, IOMMU_DOMAIN_UNMANAGED); + if (!group->blocking_domain) + return -EINVAL; + } + 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. + */ +int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner) +{ + int ret = 0; + + mutex_lock(&group->mutex); + if (group->owner_cnt) { + ret = -EPERM; + goto unlock_out; + } else { + if (group->domain && group->domain != group->default_domain) { + ret = -EBUSY; + goto unlock_out; + } + + ret = __iommu_group_alloc_blocking_domain(group); + if (ret) + goto unlock_out; + + ret = __iommu_group_set_domain(group, group->blocking_domain); + if (ret) + goto unlock_out; + group->owner = owner; + } + + group->owner_cnt++; +unlock_out: + mutex_unlock(&group->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_group_claim_dma_owner); + +/** + * 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) +{ + int ret; + + mutex_lock(&group->mutex); + if (WARN_ON(!group->owner_cnt || !group->owner)) + goto unlock_out; + + group->owner_cnt = 0; + group->owner = NULL; + ret = __iommu_group_set_domain(group, group->default_domain); + WARN(ret, "iommu driver failed to attach the default domain"); + +unlock_out: + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_group_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); |