linux/drivers/iommu/iommu.c
Mark Salter fb3e306515 iommu: Fix bus notifier breakage
iommu_bus_init() registers a bus notifier on the given bus by using
a statically defined notifier block:

  static struct notifier_block iommu_bus_nb = {
          .notifier_call = iommu_bus_notifier,
  };

This same notifier block is used for all busses. This causes a
problem for notifiers registered after iommu has registered this
callback on multiple busses. The problem is that a subsequent
notifier being registered on a bus which has this iommu notifier
will also get linked in to the notifier list of all other busses
which have this iommu notifier.

This patch fixes this by allocating the notifier_block at runtime.
Some error checking is also added to catch any allocation failure
or notifier registration error.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2014-09-25 16:46:37 +02:00

1225 lines
31 KiB
C

/*
* Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
* Author: Joerg Roedel <joerg.roedel@amd.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/types.h>
#include <linux/module.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 <trace/events/iommu.h>
static struct kset *iommu_group_kset;
static struct ida iommu_group_ida;
static struct mutex iommu_group_mutex;
struct iommu_callback_data {
const struct iommu_ops *ops;
};
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_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);
};
#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 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);
}
static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);
static void iommu_group_release(struct kobject *kobj)
{
struct iommu_group *group = to_iommu_group(kobj);
if (group->iommu_data_release)
group->iommu_data_release(group->iommu_data);
mutex_lock(&iommu_group_mutex);
ida_remove(&iommu_group_ida, group->id);
mutex_unlock(&iommu_group_mutex);
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
* @name: Optional name to associate with group, visible in sysfs
*
* 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);
BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
mutex_lock(&iommu_group_mutex);
again:
if (unlikely(0 == ida_pre_get(&iommu_group_ida, GFP_KERNEL))) {
kfree(group);
mutex_unlock(&iommu_group_mutex);
return ERR_PTR(-ENOMEM);
}
if (-EAGAIN == ida_get_new(&iommu_group_ida, &group->id))
goto again;
mutex_unlock(&iommu_group_mutex);
ret = kobject_init_and_add(&group->kobj, &iommu_group_ktype,
NULL, "%d", group->id);
if (ret) {
mutex_lock(&iommu_group_mutex);
ida_remove(&iommu_group_ida, group->id);
mutex_unlock(&iommu_group_mutex);
kfree(group);
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);
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);
/**
* 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 iommu_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) {
kfree(device);
return ret;
}
device->name = kasprintf(GFP_KERNEL, "%s", kobject_name(&dev->kobj));
rename:
if (!device->name) {
sysfs_remove_link(&dev->kobj, "iommu_group");
kfree(device);
return -ENOMEM;
}
ret = sysfs_create_link_nowarn(group->devices_kobj,
&dev->kobj, device->name);
if (ret) {
kfree(device->name);
if (ret == -EEXIST && i >= 0) {
/*
* Account for the slim chance of collision
* and append an instance to the name.
*/
device->name = kasprintf(GFP_KERNEL, "%s.%d",
kobject_name(&dev->kobj), i++);
goto rename;
}
sysfs_remove_link(&dev->kobj, "iommu_group");
kfree(device);
return ret;
}
kobject_get(group->devices_kobj);
dev->iommu_group = group;
mutex_lock(&group->mutex);
list_add_tail(&device->list, &group->devices);
mutex_unlock(&group->mutex);
/* 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);
return 0;
}
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 iommu_device *tmp_device, *device = NULL;
/* 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);
/**
* iommu_group_for_each_dev - iterate over each device in the group
* @group: the group
* @data: caller opaque data to be passed to callback function
* @fn: caller supplied callback function
*
* This function is called by group users to iterate over group devices.
* Callers should hold a reference count to the group during callback.
* The group->mutex is held across callbacks, which will block calls to
* iommu_group_add/remove_device.
*/
int iommu_group_for_each_dev(struct iommu_group *group, void *data,
int (*fn)(struct device *, void *))
{
struct iommu_device *device;
int ret = 0;
mutex_lock(&group->mutex);
list_for_each_entry(device, &group->devices, list) {
ret = fn(device->dev, data);
if (ret)
break;
}
mutex_unlock(&group->mutex);
return ret;
}
EXPORT_SYMBOL_GPL(iommu_group_for_each_dev);
/**
* iommu_group_get - Return the group for a device and increment reference
* @dev: get the group that this device belongs to
*
* This function is called by iommu drivers and users to get the group
* for the specified device. If found, the group is returned and the group
* reference in incremented, else NULL.
*/
struct iommu_group *iommu_group_get(struct device *dev)
{
struct iommu_group *group = dev->iommu_group;
if (group)
kobject_get(group->devices_kobj);
return group;
}
EXPORT_SYMBOL_GPL(iommu_group_get);
/**
* iommu_group_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_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 exisiting groups. The
* dma_alias_devfn only supports aliases 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 (((pdev->dev_flags & PCI_DEV_FLAGS_DMA_ALIAS_DEVFN) &&
pdev->dma_alias_devfn == tmp->devfn) ||
((tmp->dev_flags & PCI_DEV_FLAGS_DMA_ALIAS_DEVFN) &&
tmp->dma_alias_devfn == pdev->devfn)) {
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;
}
/*
* Use standard PCI bus topology, isolation features, and DMA alias quirks
* to find or create an IOMMU group for a device.
*/
static struct iommu_group *iommu_group_get_for_pci_dev(struct pci_dev *pdev)
{
struct group_for_pci_data data;
struct pci_bus *bus;
struct iommu_group *group = NULL;
u64 devfns[4] = { 0 };
/*
* 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();
}
/**
* 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().
*/
struct iommu_group *iommu_group_get_for_dev(struct device *dev)
{
struct iommu_group *group;
int ret;
group = iommu_group_get(dev);
if (group)
return group;
if (!dev_is_pci(dev))
return ERR_PTR(-EINVAL);
group = iommu_group_get_for_pci_dev(to_pci_dev(dev));
if (IS_ERR(group))
return group;
ret = iommu_group_add_device(group, dev);
if (ret) {
iommu_group_put(group);
return ERR_PTR(ret);
}
return group;
}
static int add_iommu_group(struct device *dev, void *data)
{
struct iommu_callback_data *cb = data;
const struct iommu_ops *ops = cb->ops;
if (!ops->add_device)
return -ENODEV;
WARN_ON(dev->iommu_group);
ops->add_device(dev);
return 0;
}
static int iommu_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
const struct iommu_ops *ops = dev->bus->iommu_ops;
struct iommu_group *group;
unsigned long group_action = 0;
/*
* 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) {
if (ops->add_device)
return ops->add_device(dev);
} else if (action == BUS_NOTIFY_DEL_DEVICE) {
if (ops->remove_device && dev->iommu_group) {
ops->remove_device(dev);
return 0;
}
}
/*
* 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;
}
static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops)
{
int err;
struct notifier_block *nb;
struct iommu_callback_data cb = {
.ops = ops,
};
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) {
kfree(nb);
return err;
}
return bus_for_each_dev(bus, NULL, &cb, add_iommu_group);
}
/**
* 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)
{
if (bus->iommu_ops != NULL)
return -EBUSY;
bus->iommu_ops = ops;
/* Do IOMMU specific setup for this bus-type */
return iommu_bus_init(bus, ops);
}
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);
struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
{
struct iommu_domain *domain;
int ret;
if (bus == NULL || bus->iommu_ops == NULL)
return NULL;
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!domain)
return NULL;
domain->ops = bus->iommu_ops;
ret = domain->ops->domain_init(domain);
if (ret)
goto out_free;
return domain;
out_free:
kfree(domain);
return NULL;
}
EXPORT_SYMBOL_GPL(iommu_domain_alloc);
void iommu_domain_free(struct iommu_domain *domain)
{
if (likely(domain->ops->domain_destroy != NULL))
domain->ops->domain_destroy(domain);
kfree(domain);
}
EXPORT_SYMBOL_GPL(iommu_domain_free);
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;
}
EXPORT_SYMBOL_GPL(iommu_attach_device);
void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
{
if (unlikely(domain->ops->detach_dev == NULL))
return;
domain->ops->detach_dev(domain, dev);
trace_detach_device_from_domain(dev);
}
EXPORT_SYMBOL_GPL(iommu_detach_device);
/*
* IOMMU groups are really the natrual 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);
}
int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)
{
return iommu_group_for_each_dev(group, domain,
iommu_group_do_attach_device);
}
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;
}
void iommu_detach_group(struct iommu_domain *domain, struct iommu_group *group)
{
iommu_group_for_each_dev(group, domain, iommu_group_do_detach_device);
}
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->ops->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;
}
int iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot)
{
unsigned long orig_iova = iova;
unsigned int min_pagesz;
size_t orig_size = size;
int ret = 0;
if (unlikely(domain->ops->map == NULL ||
domain->ops->pgsize_bitmap == 0UL))
return -ENODEV;
/* find out the minimum page size supported */
min_pagesz = 1 << __ffs(domain->ops->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 = domain->ops->map(domain, iova, paddr, pgsize, prot);
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(iova, paddr, size);
return ret;
}
EXPORT_SYMBOL_GPL(iommu_map);
size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
{
size_t unmapped_page, unmapped = 0;
unsigned int min_pagesz;
if (unlikely(domain->ops->unmap == NULL ||
domain->ops->pgsize_bitmap == 0UL))
return -ENODEV;
/* find out the minimum page size supported */
min_pagesz = 1 << __ffs(domain->ops->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 -EINVAL;
}
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 = domain->ops->unmap(domain, iova, pgsize);
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(iova, 0, size);
return unmapped;
}
EXPORT_SYMBOL_GPL(iommu_unmap);
int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr,
phys_addr_t paddr, u64 size, int prot)
{
if (unlikely(domain->ops->domain_window_enable == NULL))
return -ENODEV;
return domain->ops->domain_window_enable(domain, wnd_nr, paddr, size,
prot);
}
EXPORT_SYMBOL_GPL(iommu_domain_window_enable);
void iommu_domain_window_disable(struct iommu_domain *domain, u32 wnd_nr)
{
if (unlikely(domain->ops->domain_window_disable == NULL))
return;
return domain->ops->domain_window_disable(domain, wnd_nr);
}
EXPORT_SYMBOL_GPL(iommu_domain_window_disable);
static int __init iommu_init(void)
{
iommu_group_kset = kset_create_and_add("iommu_groups",
NULL, kernel_kobj);
ida_init(&iommu_group_ida);
mutex_init(&iommu_group_mutex);
BUG_ON(!iommu_group_kset);
return 0;
}
arch_initcall(iommu_init);
int iommu_domain_get_attr(struct iommu_domain *domain,
enum iommu_attr attr, void *data)
{
struct iommu_domain_geometry *geometry;
bool *paging;
int ret = 0;
u32 *count;
switch (attr) {
case DOMAIN_ATTR_GEOMETRY:
geometry = data;
*geometry = domain->geometry;
break;
case DOMAIN_ATTR_PAGING:
paging = data;
*paging = (domain->ops->pgsize_bitmap != 0UL);
break;
case DOMAIN_ATTR_WINDOWS:
count = data;
if (domain->ops->domain_get_windows != NULL)
*count = domain->ops->domain_get_windows(domain);
else
ret = -ENODEV;
break;
default:
if (!domain->ops->domain_get_attr)
return -EINVAL;
ret = domain->ops->domain_get_attr(domain, attr, data);
}
return ret;
}
EXPORT_SYMBOL_GPL(iommu_domain_get_attr);
int iommu_domain_set_attr(struct iommu_domain *domain,
enum iommu_attr attr, void *data)
{
int ret = 0;
u32 *count;
switch (attr) {
case DOMAIN_ATTR_WINDOWS:
count = data;
if (domain->ops->domain_set_windows != NULL)
ret = domain->ops->domain_set_windows(domain, *count);
else
ret = -ENODEV;
break;
default:
if (domain->ops->domain_set_attr == NULL)
return -EINVAL;
ret = domain->ops->domain_set_attr(domain, attr, data);
}
return ret;
}
EXPORT_SYMBOL_GPL(iommu_domain_set_attr);