diff options
Diffstat (limited to 'drivers/iommu/iommu.c')
-rw-r--r-- | drivers/iommu/iommu.c | 578 |
1 files changed, 548 insertions, 30 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index ed5e0a5..ddbdaca 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -26,60 +26,535 @@ #include <linux/slab.h> #include <linux/errno.h> #include <linux/iommu.h> +#include <linux/idr.h> +#include <linux/notifier.h> +#include <linux/err.h> + +static struct kset *iommu_group_kset; +static struct ida iommu_group_ida; +static struct mutex iommu_group_mutex; + +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 show_iommu_group(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t iommu_group_attr_show(struct kobject *kobj, + struct attribute *__attr, char *buf) { - unsigned int groupid; + struct iommu_group_attribute *attr = to_iommu_group_attr(__attr); + struct iommu_group *group = to_iommu_group(kobj); + ssize_t ret = -EIO; - if (iommu_device_group(dev, &groupid)) - return 0; + if (attr->show) + ret = attr->show(group, buf); + return ret; +} - return sprintf(buf, "%u", groupid); +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 DEVICE_ATTR(iommu_group, S_IRUGO, show_iommu_group, NULL); -static int add_iommu_group(struct device *dev, void *data) +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) { - unsigned int groupid; + 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); - if (iommu_device_group(dev, &groupid) == 0) - return device_create_file(dev, &dev_attr_iommu_group); +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); + +/** + * 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 remove_iommu_group(struct device *dev) +/** + * 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) { - unsigned int groupid; + 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; + } - if (iommu_device_group(dev, &groupid) == 0) - device_remove_file(dev, &dev_attr_iommu_group); + 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); return 0; } +EXPORT_SYMBOL_GPL(iommu_group_add_device); -static int iommu_device_notifier(struct notifier_block *nb, - unsigned long action, void *data) +/** + * 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"); + + 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 int add_iommu_group(struct device *dev, void *data) +{ + struct iommu_ops *ops = data; + + 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; + 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 (action == BUS_NOTIFY_ADD_DEVICE) - return add_iommu_group(dev, NULL); - else if (action == BUS_NOTIFY_DEL_DEVICE) - return remove_iommu_group(dev); + if (group_action) + blocking_notifier_call_chain(&group->notifier, + group_action, dev); + iommu_group_put(group); return 0; } -static struct notifier_block iommu_device_nb = { - .notifier_call = iommu_device_notifier, +static struct notifier_block iommu_bus_nb = { + .notifier_call = iommu_bus_notifier, }; static void iommu_bus_init(struct bus_type *bus, struct iommu_ops *ops) { - bus_register_notifier(bus, &iommu_device_nb); - bus_for_each_dev(bus, NULL, NULL, add_iommu_group); + bus_register_notifier(bus, &iommu_bus_nb); + bus_for_each_dev(bus, NULL, ops, add_iommu_group); } /** @@ -192,6 +667,45 @@ void iommu_detach_device(struct iommu_domain *domain, struct device *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, unsigned long iova) { @@ -336,14 +850,18 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) } EXPORT_SYMBOL_GPL(iommu_unmap); -int iommu_device_group(struct device *dev, unsigned int *groupid) +static int __init iommu_init(void) { - if (iommu_present(dev->bus) && dev->bus->iommu_ops->device_group) - return dev->bus->iommu_ops->device_group(dev, groupid); + 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 -ENODEV; + return 0; } -EXPORT_SYMBOL_GPL(iommu_device_group); +subsys_initcall(iommu_init); int iommu_domain_get_attr(struct iommu_domain *domain, enum iommu_attr attr, void *data) |