iommu.c
// 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/device.h>
#include <linux/kernel.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/iommu.h>
#include <linux/idr.h>
#include <linux/notifier.h>
#include <linux/err.h>
#include <linux/pci.h>
#include <linux/bitops.h>
#include <linux/property.h>
#include <linux/fsl/mc.h>
#include <linux/module.h>
#include <trace/events/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 = true;
static u32 iommu_cmd_line __read_mostly;
struct iommu_group {
struct kobject kobj;
struct kobject *devices_kobj;
struct list_head devices;
struct mutex mutex;
struct blocking_notifier_head notifier;
void *iommu_data;
void (*iommu_data_release)(void *iommu_data);
char *name;
int id;
struct iommu_domain *default_domain;
struct iommu_domain *domain;
struct list_head entry;
};
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_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 void __iommu_detach_group(struct iommu_domain *domain,
struct iommu_group *group);
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);
/*
* 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:
return "Translated";
default:
return "Unknown";
}
}
static int __init iommu_subsys_init(void)
{
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() && mem_encrypt_active()) {
pr_info("Memory encryption detected - Disabling default IOMMU Passthrough\n");
iommu_set_default_translated(false);
}
}
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)" : "");
return 0;
}
subsys_initcall(iommu_subsys_init);
/**
* 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)
{
/* 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 = hwdev->fwnode;
spin_lock(&iommu_device_lock);
list_add_tail(&iommu->list, &iommu_device_list);
spin_unlock(&iommu_device_lock);
return 0;
}
EXPORT_SYMBOL_GPL(iommu_device_register);
void iommu_device_unregister(struct iommu_device *iommu)
{
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)
{
iommu_fwspec_free(dev);
kfree(dev->iommu);
dev->iommu = NULL;
}
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;
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;
}
iommu_group_put(group);
if (group_list && !group->default_domain && list_empty(&group->entry))
list_add_tail(&group->entry, group_list);
iommu_device_link(iommu_dev, dev);
return 0;
out_release:
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 = dev->bus->iommu_ops;
struct iommu_group *group;
int ret;
ret = __iommu_probe_device(dev, NULL);
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.
*/
iommu_alloc_default_domain(group, dev);
if (group->default_domain) {
ret = __iommu_attach_device(group->default_domain, dev);
if (ret) {
iommu_group_put(group);
goto err_release;
}
}
iommu_create_device_direct_mappings(group, dev);
iommu_group_put(group);
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 = dev->bus->iommu_ops;
if (!dev->iommu)
return;
iommu_device_unlink(dev->iommu->iommu_dev, dev);
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(bool strict)
{
if (strict || !(iommu_cmd_line & IOMMU_CMD_LINE_STRICT))
iommu_dma_strict = strict;
}
bool iommu_get_dma_strict(struct iommu_domain *domain)
{
/* only allow lazy flushing for DMA domains */
if (domain->type == IOMMU_DOMAIN_DMA)
return iommu_dma_strict;
return true;
}
EXPORT_SYMBOL_GPL(iommu_get_dma_strict);
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);
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;
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;
}
}
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_simple_remove(&iommu_group_ida, group->id);
if (group->default_domain)
iommu_domain_free(group->default_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);
BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
ret = ida_simple_get(&iommu_group_ida, 0, 0, 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) {
ida_simple_remove(&iommu_group_ida, group->id);
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)
return ERR_PTR(ret);
ret = iommu_group_create_file(group, &iommu_group_attr_type);
if (ret)
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 || domain->type != IOMMU_DOMAIN_DMA)
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;
if (domain->ops->apply_resv_region)
domain->ops->apply_resv_region(dev, domain, entry);
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 iommu_domain *domain,
struct device *dev)
{
if (domain->ops->is_attach_deferred)
return domain->ops->is_attach_deferred(domain, 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(group->domain, dev))
ret = __iommu_attach_device(group->domain, dev);
mutex_unlock(&group->mutex);
if (ret)
goto err_put_group;
/* Notify any listeners about change to group. */
blocking_notifier_call_chain(&group->notifier,
IOMMU_GROUP_NOTIFY_ADD_DEVICE, dev);
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;
dev_info(dev, "Removing from iommu group %d\n", group->id);
/* Pre-notify listeners that a device is being removed. */
blocking_notifier_call_chain(&group->notifier,
IOMMU_GROUP_NOTIFY_DEL_DEVICE, dev);
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;
}
/**
* 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.
*/
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;
}
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_group_register_notifier - Register a notifier for group changes
* @group: the group to watch
* @nb: notifier block to signal
*
* This function allows iommu group users to track changes in a group.
* See include/linux/iommu.h for actions sent via this notifier. Caller
* should hold a reference to the group throughout notifier registration.
*/
int iommu_group_register_notifier(struct iommu_group *group,
struct notifier_block *nb)
{
return blocking_notifier_chain_register(&group->notifier, nb);
}
EXPORT_SYMBOL_GPL(iommu_group_register_notifier);
/**
* iommu_group_unregister_notifier - Unregister a notifier
* @group: the group to watch
* @nb: notifier block to signal
*
* Unregister a previously registered group notifier block.
*/
int iommu_group_unregister_notifier(struct iommu_group *group,
struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&group->notifier, nb);
}
EXPORT_SYMBOL_GPL(iommu_group_unregister_notifier);
/**
* 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;
bool has_pasid = msg->flags & IOMMU_PAGE_RESP_PASID_VALID;
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
if (!domain || !domain->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 = domain->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->bus->iommu_ops;
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->bus->iommu_ops;
struct iommu_group *group;
int ret;
group = iommu_group_get(dev);
if (group)
return group;
if (!ops)
return ERR_PTR(-EINVAL);
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;
}
ret = __iommu_probe_device(dev, group_list);
if (ret == -ENODEV)
ret = 0;
return ret;
}
static int remove_iommu_group(struct device *dev, void *data)
{
iommu_release_device(dev);
return 0;
}
static int iommu_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
unsigned long group_action = 0;
struct device *dev = data;
struct iommu_group *group;
/*
* ADD/DEL call into iommu driver ops if provided, which may
* result in ADD/DEL notifiers to group->notifier
*/
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;
}
/*
* Remaining BUS_NOTIFYs get filtered and republished to the
* group, if anyone is listening
*/
group = iommu_group_get(dev);
if (!group)
return 0;
switch (action) {
case BUS_NOTIFY_BIND_DRIVER:
group_action = IOMMU_GROUP_NOTIFY_BIND_DRIVER;
break;
case BUS_NOTIFY_BOUND_DRIVER:
group_action = IOMMU_GROUP_NOTIFY_BOUND_DRIVER;
break;
case BUS_NOTIFY_UNBIND_DRIVER:
group_action = IOMMU_GROUP_NOTIFY_UNBIND_DRIVER;
break;
case BUS_NOTIFY_UNBOUND_DRIVER:
group_action = IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER;
break;
}
if (group_action)
blocking_notifier_call_chain(&group->notifier,
group_action, dev);
iommu_group_put(group);
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(domain, 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)
{
struct iommu_domain *domain = data;
if (domain->ops->probe_finalize)
domain->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) {
/* Remove item from the list */
list_del_init(&group->entry);
mutex_lock(&group->mutex);
/* 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;
}
static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops)
{
struct notifier_block *nb;
int err;
nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
if (!nb)
return -ENOMEM;
nb->notifier_call = iommu_bus_notifier;
err = bus_register_notifier(bus, nb);
if (err)
goto out_free;
err = bus_iommu_probe(bus);
if (err)
goto out_err;
return 0;
out_err:
/* Clean up */
bus_for_each_dev(bus, NULL, NULL, remove_iommu_group);
bus_unregister_notifier(bus, nb);
out_free:
kfree(nb);
return err;
}
/**
* bus_set_iommu - set iommu-callbacks for the bus
* @bus: bus.
* @ops: the callbacks provided by the iommu-driver
*
* This function is called by an iommu driver to set the iommu methods
* used for a particular bus. Drivers for devices on that bus can use
* the iommu-api after these ops are registered.
* This special function is needed because IOMMUs are usually devices on
* the bus itself, so the iommu drivers are not initialized when the bus
* is set up. With this function the iommu-driver can set the iommu-ops
* afterwards.
*/
int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops)
{
int err;
if (ops == NULL) {
bus->iommu_ops = NULL;
return 0;
}
if (bus->iommu_ops != NULL)
return -EBUSY;
bus->iommu_ops = ops;
/* Do IOMMU specific setup for this bus-type */
err = iommu_bus_init(bus, ops);
if (err)
bus->iommu_ops = NULL;
return err;
}
EXPORT_SYMBOL_GPL(bus_set_iommu);
bool iommu_present(struct bus_type *bus)
{
return bus->iommu_ops != NULL;
}
EXPORT_SYMBOL_GPL(iommu_present);
bool iommu_capable(struct bus_type *bus, enum iommu_cap cap)
{
if (!bus->iommu_ops || !bus->iommu_ops->capable)
return false;
return bus->iommu_ops->capable(cap);
}
EXPORT_SYMBOL_GPL(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->ops = bus->iommu_ops;
domain->type = type;
/* Assume all sizes by default; the driver may override this later */
domain->pgsize_bitmap = bus->iommu_ops->pgsize_bitmap;
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)
{
domain->ops->domain_free(domain);
}
EXPORT_SYMBOL_GPL(iommu_domain_free);
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)
{
const struct iommu_ops *ops = domain->ops;
if (ops->is_attach_deferred && ops->is_attach_deferred(domain, dev))
return __iommu_attach_device(domain, dev);
return 0;
}
/*
* Check flags and other user provided data for valid combinations. We also
* make sure no reserved fields or unused flags are set. This is to ensure
* not breaking userspace in the future when these fields or flags are used.
*/
static int iommu_check_cache_invl_data(struct iommu_cache_invalidate_info *info)
{
u32 mask;
int i;
if (info->version != IOMMU_CACHE_INVALIDATE_INFO_VERSION_1)
return -EINVAL;
mask = (1 << IOMMU_CACHE_INV_TYPE_NR) - 1;
if (info->cache & ~mask)
return -EINVAL;
if (info->granularity >= IOMMU_INV_GRANU_NR)
return -EINVAL;
switch (info->granularity) {
case IOMMU_INV_GRANU_ADDR:
if (info->cache & IOMMU_CACHE_INV_TYPE_PASID)
return -EINVAL;
mask = IOMMU_INV_ADDR_FLAGS_PASID |
IOMMU_INV_ADDR_FLAGS_ARCHID |
IOMMU_INV_ADDR_FLAGS_LEAF;
if (info->granu.addr_info.flags & ~mask)
return -EINVAL;
break;
case IOMMU_INV_GRANU_PASID:
mask = IOMMU_INV_PASID_FLAGS_PASID |
IOMMU_INV_PASID_FLAGS_ARCHID;
if (info->granu.pasid_info.flags & ~mask)
return -EINVAL;
break;
case IOMMU_INV_GRANU_DOMAIN:
if (info->cache & IOMMU_CACHE_INV_TYPE_DEV_IOTLB)
return -EINVAL;
break;
default:
return -EINVAL;
}
/* Check reserved padding fields */
for (i = 0; i < sizeof(info->padding); i++) {
if (info->padding[i])
return -EINVAL;
}
return 0;
}
int iommu_uapi_cache_invalidate(struct iommu_domain *domain, struct device *dev,
void __user *uinfo)
{
struct iommu_cache_invalidate_info inv_info = { 0 };
u32 minsz;
int ret;
if (unlikely(!domain->ops->cache_invalidate))
return -ENODEV;
/*
* No new spaces can be added before the variable sized union, the
* minimum size is the offset to the union.
*/
minsz = offsetof(struct iommu_cache_invalidate_info, granu);
/* Copy minsz from user to get flags and argsz */
if (copy_from_user(&inv_info, uinfo, minsz))
return -EFAULT;
/* Fields before the variable size union are mandatory */
if (inv_info.argsz < minsz)
return -EINVAL;
/* PASID and address granu require additional info beyond minsz */
if (inv_info.granularity == IOMMU_INV_GRANU_PASID &&
inv_info.argsz < offsetofend(struct iommu_cache_invalidate_info, granu.pasid_info))
return -EINVAL;
if (inv_info.granularity == IOMMU_INV_GRANU_ADDR &&
inv_info.argsz < offsetofend(struct iommu_cache_invalidate_info, granu.addr_info))
return -EINVAL;
/*
* User might be using a newer UAPI header which has a larger data
* size, we shall support the existing flags within the current
* size. Copy the remaining user data _after_ minsz but not more
* than the current kernel supported size.
*/
if (copy_from_user((void *)&inv_info + minsz, uinfo + minsz,
min_t(u32, inv_info.argsz, sizeof(inv_info)) - minsz))
return -EFAULT;
/* Now the argsz is validated, check the content */
ret = iommu_check_cache_invl_data(&inv_info);
if (ret)
return ret;
return domain->ops->cache_invalidate(domain, dev, &inv_info);
}
EXPORT_SYMBOL_GPL(iommu_uapi_cache_invalidate);
static int iommu_check_bind_data(struct iommu_gpasid_bind_data *data)
{
u64 mask;
int i;
if (data->version != IOMMU_GPASID_BIND_VERSION_1)
return -EINVAL;
/* Check the range of supported formats */
if (data->format >= IOMMU_PASID_FORMAT_LAST)
return -EINVAL;
/* Check all flags */
mask = IOMMU_SVA_GPASID_VAL;
if (data->flags & ~mask)
return -EINVAL;
/* Check reserved padding fields */
for (i = 0; i < sizeof(data->padding); i++) {
if (data->padding[i])
return -EINVAL;
}
return 0;
}
static int iommu_sva_prepare_bind_data(void __user *udata,
struct iommu_gpasid_bind_data *data)
{
u32 minsz;
/*
* No new spaces can be added before the variable sized union, the
* minimum size is the offset to the union.
*/
minsz = offsetof(struct iommu_gpasid_bind_data, vendor);
/* Copy minsz from user to get flags and argsz */
if (copy_from_user(data, udata, minsz))
return -EFAULT;
/* Fields before the variable size union are mandatory */
if (data->argsz < minsz)
return -EINVAL;
/*
* User might be using a newer UAPI header, we shall let IOMMU vendor
* driver decide on what size it needs. Since the guest PASID bind data
* can be vendor specific, larger argsz could be the result of extension
* for one vendor but it should not affect another vendor.
* Copy the remaining user data _after_ minsz
*/
if (copy_from_user((void *)data + minsz, udata + minsz,
min_t(u32, data->argsz, sizeof(*data)) - minsz))
return -EFAULT;
return iommu_check_bind_data(data);
}
int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, struct device *dev,
void __user *udata)
{
struct iommu_gpasid_bind_data data = { 0 };
int ret;
if (unlikely(!domain->ops->sva_bind_gpasid))
return -ENODEV;
ret = iommu_sva_prepare_bind_data(udata, &data);
if (ret)
return ret;
return domain->ops->sva_bind_gpasid(domain, dev, &data);
}
EXPORT_SYMBOL_GPL(iommu_uapi_sva_bind_gpasid);
int iommu_sva_unbind_gpasid(struct iommu_domain *domain, struct device *dev,
ioasid_t pasid)
{
if (unlikely(!domain->ops->sva_unbind_gpasid))
return -ENODEV;
return domain->ops->sva_unbind_gpasid(dev, pasid);
}
EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid);
int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, struct device *dev,
void __user *udata)
{
struct iommu_gpasid_bind_data data = { 0 };
int ret;
if (unlikely(!domain->ops->sva_bind_gpasid))
return -ENODEV;
ret = iommu_sva_prepare_bind_data(udata, &data);
if (ret)
return ret;
return iommu_sva_unbind_gpasid(domain, dev, data.hpasid);
}
EXPORT_SYMBOL_GPL(iommu_uapi_sva_unbind_gpasid);
static void __iommu_detach_device(struct iommu_domain *domain,
struct device *dev)
{
if (iommu_is_attach_deferred(domain, dev))
return;
if (unlikely(domain->ops->detach_dev == NULL))
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 (iommu_group_device_count(group) != 1) {
WARN_ON(1);
goto out_unlock;
}
__iommu_detach_group(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->default_domain && group->domain != group->default_domain)
return -EBUSY;
ret = __iommu_group_for_each_dev(group, domain,
iommu_group_do_attach_device);
if (ret == 0)
group->domain = 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 void __iommu_detach_group(struct iommu_domain *domain,
struct iommu_group *group)
{
int ret;
if (!group->default_domain) {
__iommu_group_for_each_dev(group, domain,
iommu_group_do_detach_device);
group->domain = NULL;
return;
}
if (group->domain == group->default_domain)
return;
/* Detach by re-attaching to the default domain */
ret = __iommu_group_for_each_dev(group, group->default_domain,
iommu_group_do_attach_device);
if (ret != 0)
WARN_ON(1);
else
group->domain = group->default_domain;
}
void iommu_detach_group(struct iommu_domain *domain, struct iommu_group *group)
{
mutex_lock(&group->mutex);
__iommu_detach_group(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 (unlikely(domain->ops->iova_to_phys == NULL))
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 addr_merge, size_t size)
{
unsigned int pgsize_idx;
size_t pgsize;
/* Max page size that still fits into 'size' */
pgsize_idx = __fls(size);
/* need to consider alignment requirements ? */
if (likely(addr_merge)) {
/* Max page size allowed by address */
unsigned int align_pgsize_idx = __ffs(addr_merge);
pgsize_idx = min(pgsize_idx, align_pgsize_idx);
}
/* build a mask of acceptable page sizes */
pgsize = (1UL << (pgsize_idx + 1)) - 1;
/* throw away page sizes not supported by the hardware */
pgsize &= domain->pgsize_bitmap;
/* make sure we're still sane */
BUG_ON(!pgsize);
/* pick the biggest page */
pgsize_idx = __fls(pgsize);
pgsize = 1UL << pgsize_idx;
return pgsize;
}
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_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 == NULL ||
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 pgsize = iommu_pgsize(domain, iova | paddr, size);
pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx\n",
iova, &paddr, pgsize);
ret = ops->map(domain, iova, paddr, pgsize, prot, gfp);
if (ret)
break;
iova += pgsize;
paddr += pgsize;
size -= pgsize;
}
/* 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_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(struct iommu_domain *domain,
unsigned long iova, size_t size,
struct iommu_iotlb_gather *iotlb_gather)
{
const struct iommu_ops *ops = domain->ops;
size_t unmapped_page, unmapped = 0;
unsigned long orig_iova = iova;
unsigned int min_pagesz;
if (unlikely(ops->unmap == NULL ||
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) {
size_t pgsize = iommu_pgsize(domain, iova, size - unmapped);
unmapped_page = ops->unmap(domain, iova, pgsize, 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 size_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_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 (len) {
len += sg->length;
} else {
len = sg->length;
start = s_phys;
}
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 0;
}
size_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);
size_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->bus->iommu_ops;
if (ops && ops->get_resv_regions)
ops->get_resv_regions(dev, list);
}
void iommu_put_resv_regions(struct device *dev, struct list_head *list)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
if (ops && ops->put_resv_regions)
ops->put_resv_regions(dev, list);
}
/**
* generic_iommu_put_resv_regions - Reserved region driver helper
* @dev: device for which to free reserved regions
* @list: reserved region list for device
*
* IOMMU drivers can use this to implement their .put_resv_regions() callback
* for simple reservations. Memory allocated for each reserved region will be
* freed. If an IOMMU driver allocates additional resources per region, it is
* going to have to implement a custom callback.
*/
void generic_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)
kfree(entry);
}
EXPORT_SYMBOL(generic_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)
{
struct iommu_resv_region *region;
region = kzalloc(sizeof(*region), GFP_KERNEL);
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.
* For example, before disabling the aux-domain feature, the device driver
* should detach all aux-domains. Otherwise, this will return -EBUSY.
*/
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);
bool iommu_dev_feature_enabled(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_feat_enabled)
return ops->dev_feat_enabled(dev, feat);
}
return false;
}
EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
/*
* Aux-domain specific attach/detach.
*
* Only works if iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) returns
* true. Also, as long as domains are attached to a device through this
* interface, any tries to call iommu_attach_device() should fail
* (iommu_detach_device() can't fail, so we fail when trying to re-attach).
* This should make us safe against a device being attached to a guest as a
* whole while there are still pasid users on it (aux and sva).
*/
int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
{
int ret = -ENODEV;
if (domain->ops->aux_attach_dev)
ret = domain->ops->aux_attach_dev(domain, dev);
if (!ret)
trace_attach_device_to_domain(dev);
return ret;
}
EXPORT_SYMBOL_GPL(iommu_aux_attach_device);
void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
{
if (domain->ops->aux_detach_dev) {
domain->ops->aux_detach_dev(domain, dev);
trace_detach_device_from_domain(dev);
}
}
EXPORT_SYMBOL_GPL(iommu_aux_detach_device);
int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
{
int ret = -ENODEV;
if (domain->ops->aux_get_pasid)
ret = domain->ops->aux_get_pasid(domain, dev);
return ret;
}
EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);
/**
* 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
*
* 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->bus->iommu_ops;
if (!ops || !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->bus->iommu_ops;
if (!ops || !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 = handle->dev->bus->iommu_ops;
if (!ops || !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;
if (!group)
return -EINVAL;
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;
}
/* 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 ubind the
* drivers from the devices in the iommu group. Return failure if this doesn't
* meet.
*
* 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))
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, "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)) {
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;
}
