| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright(c) 2017-2018 Intel Corporation. All rights reserved. */ |
| #include <linux/memremap.h> |
| #include <linux/device.h> |
| #include <linux/mutex.h> |
| #include <linux/list.h> |
| #include <linux/slab.h> |
| #include <linux/dax.h> |
| #include <linux/io.h> |
| #include "dax-private.h" |
| #include "bus.h" |
| |
| static DEFINE_MUTEX(dax_bus_lock); |
| |
| #define DAX_NAME_LEN 30 |
| struct dax_id { |
| struct list_head list; |
| char dev_name[DAX_NAME_LEN]; |
| }; |
| |
| static int dax_bus_uevent(struct device *dev, struct kobj_uevent_env *env) |
| { |
| /* |
| * We only ever expect to handle device-dax instances, i.e. the |
| * @type argument to MODULE_ALIAS_DAX_DEVICE() is always zero |
| */ |
| return add_uevent_var(env, "MODALIAS=" DAX_DEVICE_MODALIAS_FMT, 0); |
| } |
| |
| static struct dax_device_driver *to_dax_drv(struct device_driver *drv) |
| { |
| return container_of(drv, struct dax_device_driver, drv); |
| } |
| |
| static struct dax_id *__dax_match_id(struct dax_device_driver *dax_drv, |
| const char *dev_name) |
| { |
| struct dax_id *dax_id; |
| |
| lockdep_assert_held(&dax_bus_lock); |
| |
| list_for_each_entry(dax_id, &dax_drv->ids, list) |
| if (sysfs_streq(dax_id->dev_name, dev_name)) |
| return dax_id; |
| return NULL; |
| } |
| |
| static int dax_match_id(struct dax_device_driver *dax_drv, struct device *dev) |
| { |
| int match; |
| |
| mutex_lock(&dax_bus_lock); |
| match = !!__dax_match_id(dax_drv, dev_name(dev)); |
| mutex_unlock(&dax_bus_lock); |
| |
| return match; |
| } |
| |
| enum id_action { |
| ID_REMOVE, |
| ID_ADD, |
| }; |
| |
| static ssize_t do_id_store(struct device_driver *drv, const char *buf, |
| size_t count, enum id_action action) |
| { |
| struct dax_device_driver *dax_drv = to_dax_drv(drv); |
| unsigned int region_id, id; |
| char devname[DAX_NAME_LEN]; |
| struct dax_id *dax_id; |
| ssize_t rc = count; |
| int fields; |
| |
| fields = sscanf(buf, "dax%d.%d", ®ion_id, &id); |
| if (fields != 2) |
| return -EINVAL; |
| sprintf(devname, "dax%d.%d", region_id, id); |
| if (!sysfs_streq(buf, devname)) |
| return -EINVAL; |
| |
| mutex_lock(&dax_bus_lock); |
| dax_id = __dax_match_id(dax_drv, buf); |
| if (!dax_id) { |
| if (action == ID_ADD) { |
| dax_id = kzalloc(sizeof(*dax_id), GFP_KERNEL); |
| if (dax_id) { |
| strncpy(dax_id->dev_name, buf, DAX_NAME_LEN); |
| list_add(&dax_id->list, &dax_drv->ids); |
| } else |
| rc = -ENOMEM; |
| } |
| } else if (action == ID_REMOVE) { |
| list_del(&dax_id->list); |
| kfree(dax_id); |
| } |
| mutex_unlock(&dax_bus_lock); |
| |
| if (rc < 0) |
| return rc; |
| if (action == ID_ADD) |
| rc = driver_attach(drv); |
| if (rc) |
| return rc; |
| return count; |
| } |
| |
| static ssize_t new_id_store(struct device_driver *drv, const char *buf, |
| size_t count) |
| { |
| return do_id_store(drv, buf, count, ID_ADD); |
| } |
| static DRIVER_ATTR_WO(new_id); |
| |
| static ssize_t remove_id_store(struct device_driver *drv, const char *buf, |
| size_t count) |
| { |
| return do_id_store(drv, buf, count, ID_REMOVE); |
| } |
| static DRIVER_ATTR_WO(remove_id); |
| |
| static struct attribute *dax_drv_attrs[] = { |
| &driver_attr_new_id.attr, |
| &driver_attr_remove_id.attr, |
| NULL, |
| }; |
| ATTRIBUTE_GROUPS(dax_drv); |
| |
| static int dax_bus_match(struct device *dev, struct device_driver *drv); |
| |
| /* |
| * Static dax regions are regions created by an external subsystem |
| * nvdimm where a single range is assigned. Its boundaries are by the external |
| * subsystem and are usually limited to one physical memory range. For example, |
| * for PMEM it is usually defined by NVDIMM Namespace boundaries (i.e. a |
| * single contiguous range) |
| * |
| * On dynamic dax regions, the assigned region can be partitioned by dax core |
| * into multiple subdivisions. A subdivision is represented into one |
| * /dev/daxN.M device composed by one or more potentially discontiguous ranges. |
| * |
| * When allocating a dax region, drivers must set whether it's static |
| * (IORESOURCE_DAX_STATIC). On static dax devices, the @pgmap is pre-assigned |
| * to dax core when calling devm_create_dev_dax(), whereas in dynamic dax |
| * devices it is NULL but afterwards allocated by dax core on device ->probe(). |
| * Care is needed to make sure that dynamic dax devices are torn down with a |
| * cleared @pgmap field (see kill_dev_dax()). |
| */ |
| static bool is_static(struct dax_region *dax_region) |
| { |
| return (dax_region->res.flags & IORESOURCE_DAX_STATIC) != 0; |
| } |
| |
| bool static_dev_dax(struct dev_dax *dev_dax) |
| { |
| return is_static(dev_dax->region); |
| } |
| EXPORT_SYMBOL_GPL(static_dev_dax); |
| |
| static u64 dev_dax_size(struct dev_dax *dev_dax) |
| { |
| u64 size = 0; |
| int i; |
| |
| device_lock_assert(&dev_dax->dev); |
| |
| for (i = 0; i < dev_dax->nr_range; i++) |
| size += range_len(&dev_dax->ranges[i].range); |
| |
| return size; |
| } |
| |
| static int dax_bus_probe(struct device *dev) |
| { |
| struct dax_device_driver *dax_drv = to_dax_drv(dev->driver); |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| struct dax_region *dax_region = dev_dax->region; |
| int rc; |
| |
| if (dev_dax_size(dev_dax) == 0 || dev_dax->id < 0) |
| return -ENXIO; |
| |
| rc = dax_drv->probe(dev_dax); |
| |
| if (rc || is_static(dax_region)) |
| return rc; |
| |
| /* |
| * Track new seed creation only after successful probe of the |
| * previous seed. |
| */ |
| if (dax_region->seed == dev) |
| dax_region->seed = NULL; |
| |
| return 0; |
| } |
| |
| static void dax_bus_remove(struct device *dev) |
| { |
| struct dax_device_driver *dax_drv = to_dax_drv(dev->driver); |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| |
| if (dax_drv->remove) |
| dax_drv->remove(dev_dax); |
| } |
| |
| static struct bus_type dax_bus_type = { |
| .name = "dax", |
| .uevent = dax_bus_uevent, |
| .match = dax_bus_match, |
| .probe = dax_bus_probe, |
| .remove = dax_bus_remove, |
| .drv_groups = dax_drv_groups, |
| }; |
| |
| static int dax_bus_match(struct device *dev, struct device_driver *drv) |
| { |
| struct dax_device_driver *dax_drv = to_dax_drv(drv); |
| |
| /* |
| * All but the 'device-dax' driver, which has 'match_always' |
| * set, requires an exact id match. |
| */ |
| if (dax_drv->match_always) |
| return 1; |
| |
| return dax_match_id(dax_drv, dev); |
| } |
| |
| /* |
| * Rely on the fact that drvdata is set before the attributes are |
| * registered, and that the attributes are unregistered before drvdata |
| * is cleared to assume that drvdata is always valid. |
| */ |
| static ssize_t id_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| |
| return sprintf(buf, "%d\n", dax_region->id); |
| } |
| static DEVICE_ATTR_RO(id); |
| |
| static ssize_t region_size_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| |
| return sprintf(buf, "%llu\n", (unsigned long long) |
| resource_size(&dax_region->res)); |
| } |
| static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, |
| region_size_show, NULL); |
| |
| static ssize_t region_align_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| |
| return sprintf(buf, "%u\n", dax_region->align); |
| } |
| static struct device_attribute dev_attr_region_align = |
| __ATTR(align, 0400, region_align_show, NULL); |
| |
| #define for_each_dax_region_resource(dax_region, res) \ |
| for (res = (dax_region)->res.child; res; res = res->sibling) |
| |
| static unsigned long long dax_region_avail_size(struct dax_region *dax_region) |
| { |
| resource_size_t size = resource_size(&dax_region->res); |
| struct resource *res; |
| |
| device_lock_assert(dax_region->dev); |
| |
| for_each_dax_region_resource(dax_region, res) |
| size -= resource_size(res); |
| return size; |
| } |
| |
| static ssize_t available_size_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| unsigned long long size; |
| |
| device_lock(dev); |
| size = dax_region_avail_size(dax_region); |
| device_unlock(dev); |
| |
| return sprintf(buf, "%llu\n", size); |
| } |
| static DEVICE_ATTR_RO(available_size); |
| |
| static ssize_t seed_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| struct device *seed; |
| ssize_t rc; |
| |
| if (is_static(dax_region)) |
| return -EINVAL; |
| |
| device_lock(dev); |
| seed = dax_region->seed; |
| rc = sprintf(buf, "%s\n", seed ? dev_name(seed) : ""); |
| device_unlock(dev); |
| |
| return rc; |
| } |
| static DEVICE_ATTR_RO(seed); |
| |
| static ssize_t create_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| struct device *youngest; |
| ssize_t rc; |
| |
| if (is_static(dax_region)) |
| return -EINVAL; |
| |
| device_lock(dev); |
| youngest = dax_region->youngest; |
| rc = sprintf(buf, "%s\n", youngest ? dev_name(youngest) : ""); |
| device_unlock(dev); |
| |
| return rc; |
| } |
| |
| static ssize_t create_store(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| unsigned long long avail; |
| ssize_t rc; |
| int val; |
| |
| if (is_static(dax_region)) |
| return -EINVAL; |
| |
| rc = kstrtoint(buf, 0, &val); |
| if (rc) |
| return rc; |
| if (val != 1) |
| return -EINVAL; |
| |
| device_lock(dev); |
| avail = dax_region_avail_size(dax_region); |
| if (avail == 0) |
| rc = -ENOSPC; |
| else { |
| struct dev_dax_data data = { |
| .dax_region = dax_region, |
| .size = 0, |
| .id = -1, |
| }; |
| struct dev_dax *dev_dax = devm_create_dev_dax(&data); |
| |
| if (IS_ERR(dev_dax)) |
| rc = PTR_ERR(dev_dax); |
| else { |
| /* |
| * In support of crafting multiple new devices |
| * simultaneously multiple seeds can be created, |
| * but only the first one that has not been |
| * successfully bound is tracked as the region |
| * seed. |
| */ |
| if (!dax_region->seed) |
| dax_region->seed = &dev_dax->dev; |
| dax_region->youngest = &dev_dax->dev; |
| rc = len; |
| } |
| } |
| device_unlock(dev); |
| |
| return rc; |
| } |
| static DEVICE_ATTR_RW(create); |
| |
| void kill_dev_dax(struct dev_dax *dev_dax) |
| { |
| struct dax_device *dax_dev = dev_dax->dax_dev; |
| struct inode *inode = dax_inode(dax_dev); |
| |
| kill_dax(dax_dev); |
| unmap_mapping_range(inode->i_mapping, 0, 0, 1); |
| |
| /* |
| * Dynamic dax region have the pgmap allocated via dev_kzalloc() |
| * and thus freed by devm. Clear the pgmap to not have stale pgmap |
| * ranges on probe() from previous reconfigurations of region devices. |
| */ |
| if (!static_dev_dax(dev_dax)) |
| dev_dax->pgmap = NULL; |
| } |
| EXPORT_SYMBOL_GPL(kill_dev_dax); |
| |
| static void trim_dev_dax_range(struct dev_dax *dev_dax) |
| { |
| int i = dev_dax->nr_range - 1; |
| struct range *range = &dev_dax->ranges[i].range; |
| struct dax_region *dax_region = dev_dax->region; |
| |
| device_lock_assert(dax_region->dev); |
| dev_dbg(&dev_dax->dev, "delete range[%d]: %#llx:%#llx\n", i, |
| (unsigned long long)range->start, |
| (unsigned long long)range->end); |
| |
| __release_region(&dax_region->res, range->start, range_len(range)); |
| if (--dev_dax->nr_range == 0) { |
| kfree(dev_dax->ranges); |
| dev_dax->ranges = NULL; |
| } |
| } |
| |
| static void free_dev_dax_ranges(struct dev_dax *dev_dax) |
| { |
| while (dev_dax->nr_range) |
| trim_dev_dax_range(dev_dax); |
| } |
| |
| static void unregister_dev_dax(void *dev) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| |
| dev_dbg(dev, "%s\n", __func__); |
| |
| kill_dev_dax(dev_dax); |
| device_del(dev); |
| free_dev_dax_ranges(dev_dax); |
| put_device(dev); |
| } |
| |
| static void dax_region_free(struct kref *kref) |
| { |
| struct dax_region *dax_region; |
| |
| dax_region = container_of(kref, struct dax_region, kref); |
| kfree(dax_region); |
| } |
| |
| void dax_region_put(struct dax_region *dax_region) |
| { |
| kref_put(&dax_region->kref, dax_region_free); |
| } |
| EXPORT_SYMBOL_GPL(dax_region_put); |
| |
| /* a return value >= 0 indicates this invocation invalidated the id */ |
| static int __free_dev_dax_id(struct dev_dax *dev_dax) |
| { |
| struct device *dev = &dev_dax->dev; |
| struct dax_region *dax_region; |
| int rc = dev_dax->id; |
| |
| device_lock_assert(dev); |
| |
| if (!dev_dax->dyn_id || dev_dax->id < 0) |
| return -1; |
| dax_region = dev_dax->region; |
| ida_free(&dax_region->ida, dev_dax->id); |
| dax_region_put(dax_region); |
| dev_dax->id = -1; |
| return rc; |
| } |
| |
| static int free_dev_dax_id(struct dev_dax *dev_dax) |
| { |
| struct device *dev = &dev_dax->dev; |
| int rc; |
| |
| device_lock(dev); |
| rc = __free_dev_dax_id(dev_dax); |
| device_unlock(dev); |
| return rc; |
| } |
| |
| static int alloc_dev_dax_id(struct dev_dax *dev_dax) |
| { |
| struct dax_region *dax_region = dev_dax->region; |
| int id; |
| |
| id = ida_alloc(&dax_region->ida, GFP_KERNEL); |
| if (id < 0) |
| return id; |
| kref_get(&dax_region->kref); |
| dev_dax->dyn_id = true; |
| dev_dax->id = id; |
| return id; |
| } |
| |
| static ssize_t delete_store(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| struct dev_dax *dev_dax; |
| struct device *victim; |
| bool do_del = false; |
| int rc; |
| |
| if (is_static(dax_region)) |
| return -EINVAL; |
| |
| victim = device_find_child_by_name(dax_region->dev, buf); |
| if (!victim) |
| return -ENXIO; |
| |
| device_lock(dev); |
| device_lock(victim); |
| dev_dax = to_dev_dax(victim); |
| if (victim->driver || dev_dax_size(dev_dax)) |
| rc = -EBUSY; |
| else { |
| /* |
| * Invalidate the device so it does not become active |
| * again, but always preserve device-id-0 so that |
| * /sys/bus/dax/ is guaranteed to be populated while any |
| * dax_region is registered. |
| */ |
| if (dev_dax->id > 0) { |
| do_del = __free_dev_dax_id(dev_dax) >= 0; |
| rc = len; |
| if (dax_region->seed == victim) |
| dax_region->seed = NULL; |
| if (dax_region->youngest == victim) |
| dax_region->youngest = NULL; |
| } else |
| rc = -EBUSY; |
| } |
| device_unlock(victim); |
| |
| /* won the race to invalidate the device, clean it up */ |
| if (do_del) |
| devm_release_action(dev, unregister_dev_dax, victim); |
| device_unlock(dev); |
| put_device(victim); |
| |
| return rc; |
| } |
| static DEVICE_ATTR_WO(delete); |
| |
| static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a, |
| int n) |
| { |
| struct device *dev = container_of(kobj, struct device, kobj); |
| struct dax_region *dax_region = dev_get_drvdata(dev); |
| |
| if (is_static(dax_region)) |
| if (a == &dev_attr_available_size.attr |
| || a == &dev_attr_create.attr |
| || a == &dev_attr_seed.attr |
| || a == &dev_attr_delete.attr) |
| return 0; |
| return a->mode; |
| } |
| |
| static struct attribute *dax_region_attributes[] = { |
| &dev_attr_available_size.attr, |
| &dev_attr_region_size.attr, |
| &dev_attr_region_align.attr, |
| &dev_attr_create.attr, |
| &dev_attr_seed.attr, |
| &dev_attr_delete.attr, |
| &dev_attr_id.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group dax_region_attribute_group = { |
| .name = "dax_region", |
| .attrs = dax_region_attributes, |
| .is_visible = dax_region_visible, |
| }; |
| |
| static const struct attribute_group *dax_region_attribute_groups[] = { |
| &dax_region_attribute_group, |
| NULL, |
| }; |
| |
| static void dax_region_unregister(void *region) |
| { |
| struct dax_region *dax_region = region; |
| |
| sysfs_remove_groups(&dax_region->dev->kobj, |
| dax_region_attribute_groups); |
| dax_region_put(dax_region); |
| } |
| |
| struct dax_region *alloc_dax_region(struct device *parent, int region_id, |
| struct range *range, int target_node, unsigned int align, |
| unsigned long flags) |
| { |
| struct dax_region *dax_region; |
| |
| /* |
| * The DAX core assumes that it can store its private data in |
| * parent->driver_data. This WARN is a reminder / safeguard for |
| * developers of device-dax drivers. |
| */ |
| if (dev_get_drvdata(parent)) { |
| dev_WARN(parent, "dax core failed to setup private data\n"); |
| return NULL; |
| } |
| |
| if (!IS_ALIGNED(range->start, align) |
| || !IS_ALIGNED(range_len(range), align)) |
| return NULL; |
| |
| dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); |
| if (!dax_region) |
| return NULL; |
| |
| dev_set_drvdata(parent, dax_region); |
| kref_init(&dax_region->kref); |
| dax_region->id = region_id; |
| dax_region->align = align; |
| dax_region->dev = parent; |
| dax_region->target_node = target_node; |
| ida_init(&dax_region->ida); |
| dax_region->res = (struct resource) { |
| .start = range->start, |
| .end = range->end, |
| .flags = IORESOURCE_MEM | flags, |
| }; |
| |
| if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { |
| kfree(dax_region); |
| return NULL; |
| } |
| |
| kref_get(&dax_region->kref); |
| if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region)) |
| return NULL; |
| return dax_region; |
| } |
| EXPORT_SYMBOL_GPL(alloc_dax_region); |
| |
| static void dax_mapping_release(struct device *dev) |
| { |
| struct dax_mapping *mapping = to_dax_mapping(dev); |
| struct device *parent = dev->parent; |
| struct dev_dax *dev_dax = to_dev_dax(parent); |
| |
| ida_free(&dev_dax->ida, mapping->id); |
| kfree(mapping); |
| put_device(parent); |
| } |
| |
| static void unregister_dax_mapping(void *data) |
| { |
| struct device *dev = data; |
| struct dax_mapping *mapping = to_dax_mapping(dev); |
| struct dev_dax *dev_dax = to_dev_dax(dev->parent); |
| struct dax_region *dax_region = dev_dax->region; |
| |
| dev_dbg(dev, "%s\n", __func__); |
| |
| device_lock_assert(dax_region->dev); |
| |
| dev_dax->ranges[mapping->range_id].mapping = NULL; |
| mapping->range_id = -1; |
| |
| device_del(dev); |
| put_device(dev); |
| } |
| |
| static struct dev_dax_range *get_dax_range(struct device *dev) |
| { |
| struct dax_mapping *mapping = to_dax_mapping(dev); |
| struct dev_dax *dev_dax = to_dev_dax(dev->parent); |
| struct dax_region *dax_region = dev_dax->region; |
| |
| device_lock(dax_region->dev); |
| if (mapping->range_id < 0) { |
| device_unlock(dax_region->dev); |
| return NULL; |
| } |
| |
| return &dev_dax->ranges[mapping->range_id]; |
| } |
| |
| static void put_dax_range(struct dev_dax_range *dax_range) |
| { |
| struct dax_mapping *mapping = dax_range->mapping; |
| struct dev_dax *dev_dax = to_dev_dax(mapping->dev.parent); |
| struct dax_region *dax_region = dev_dax->region; |
| |
| device_unlock(dax_region->dev); |
| } |
| |
| static ssize_t start_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dev_dax_range *dax_range; |
| ssize_t rc; |
| |
| dax_range = get_dax_range(dev); |
| if (!dax_range) |
| return -ENXIO; |
| rc = sprintf(buf, "%#llx\n", dax_range->range.start); |
| put_dax_range(dax_range); |
| |
| return rc; |
| } |
| static DEVICE_ATTR(start, 0400, start_show, NULL); |
| |
| static ssize_t end_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dev_dax_range *dax_range; |
| ssize_t rc; |
| |
| dax_range = get_dax_range(dev); |
| if (!dax_range) |
| return -ENXIO; |
| rc = sprintf(buf, "%#llx\n", dax_range->range.end); |
| put_dax_range(dax_range); |
| |
| return rc; |
| } |
| static DEVICE_ATTR(end, 0400, end_show, NULL); |
| |
| static ssize_t pgoff_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dev_dax_range *dax_range; |
| ssize_t rc; |
| |
| dax_range = get_dax_range(dev); |
| if (!dax_range) |
| return -ENXIO; |
| rc = sprintf(buf, "%#lx\n", dax_range->pgoff); |
| put_dax_range(dax_range); |
| |
| return rc; |
| } |
| static DEVICE_ATTR(page_offset, 0400, pgoff_show, NULL); |
| |
| static struct attribute *dax_mapping_attributes[] = { |
| &dev_attr_start.attr, |
| &dev_attr_end.attr, |
| &dev_attr_page_offset.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group dax_mapping_attribute_group = { |
| .attrs = dax_mapping_attributes, |
| }; |
| |
| static const struct attribute_group *dax_mapping_attribute_groups[] = { |
| &dax_mapping_attribute_group, |
| NULL, |
| }; |
| |
| static struct device_type dax_mapping_type = { |
| .release = dax_mapping_release, |
| .groups = dax_mapping_attribute_groups, |
| }; |
| |
| static int devm_register_dax_mapping(struct dev_dax *dev_dax, int range_id) |
| { |
| struct dax_region *dax_region = dev_dax->region; |
| struct dax_mapping *mapping; |
| struct device *dev; |
| int rc; |
| |
| device_lock_assert(dax_region->dev); |
| |
| if (dev_WARN_ONCE(&dev_dax->dev, !dax_region->dev->driver, |
| "region disabled\n")) |
| return -ENXIO; |
| |
| mapping = kzalloc(sizeof(*mapping), GFP_KERNEL); |
| if (!mapping) |
| return -ENOMEM; |
| mapping->range_id = range_id; |
| mapping->id = ida_alloc(&dev_dax->ida, GFP_KERNEL); |
| if (mapping->id < 0) { |
| kfree(mapping); |
| return -ENOMEM; |
| } |
| dev_dax->ranges[range_id].mapping = mapping; |
| dev = &mapping->dev; |
| device_initialize(dev); |
| dev->parent = &dev_dax->dev; |
| get_device(dev->parent); |
| dev->type = &dax_mapping_type; |
| dev_set_name(dev, "mapping%d", mapping->id); |
| rc = device_add(dev); |
| if (rc) { |
| put_device(dev); |
| return rc; |
| } |
| |
| rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_mapping, |
| dev); |
| if (rc) |
| return rc; |
| return 0; |
| } |
| |
| static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start, |
| resource_size_t size) |
| { |
| struct dax_region *dax_region = dev_dax->region; |
| struct resource *res = &dax_region->res; |
| struct device *dev = &dev_dax->dev; |
| struct dev_dax_range *ranges; |
| unsigned long pgoff = 0; |
| struct resource *alloc; |
| int i, rc; |
| |
| device_lock_assert(dax_region->dev); |
| |
| /* handle the seed alloc special case */ |
| if (!size) { |
| if (dev_WARN_ONCE(dev, dev_dax->nr_range, |
| "0-size allocation must be first\n")) |
| return -EBUSY; |
| /* nr_range == 0 is elsewhere special cased as 0-size device */ |
| return 0; |
| } |
| |
| alloc = __request_region(res, start, size, dev_name(dev), 0); |
| if (!alloc) |
| return -ENOMEM; |
| |
| ranges = krealloc(dev_dax->ranges, sizeof(*ranges) |
| * (dev_dax->nr_range + 1), GFP_KERNEL); |
| if (!ranges) { |
| __release_region(res, alloc->start, resource_size(alloc)); |
| return -ENOMEM; |
| } |
| |
| for (i = 0; i < dev_dax->nr_range; i++) |
| pgoff += PHYS_PFN(range_len(&ranges[i].range)); |
| dev_dax->ranges = ranges; |
| ranges[dev_dax->nr_range++] = (struct dev_dax_range) { |
| .pgoff = pgoff, |
| .range = { |
| .start = alloc->start, |
| .end = alloc->end, |
| }, |
| }; |
| |
| dev_dbg(dev, "alloc range[%d]: %pa:%pa\n", dev_dax->nr_range - 1, |
| &alloc->start, &alloc->end); |
| /* |
| * A dev_dax instance must be registered before mapping device |
| * children can be added. Defer to devm_create_dev_dax() to add |
| * the initial mapping device. |
| */ |
| if (!device_is_registered(&dev_dax->dev)) |
| return 0; |
| |
| rc = devm_register_dax_mapping(dev_dax, dev_dax->nr_range - 1); |
| if (rc) |
| trim_dev_dax_range(dev_dax); |
| |
| return rc; |
| } |
| |
| static int adjust_dev_dax_range(struct dev_dax *dev_dax, struct resource *res, resource_size_t size) |
| { |
| int last_range = dev_dax->nr_range - 1; |
| struct dev_dax_range *dax_range = &dev_dax->ranges[last_range]; |
| struct dax_region *dax_region = dev_dax->region; |
| bool is_shrink = resource_size(res) > size; |
| struct range *range = &dax_range->range; |
| struct device *dev = &dev_dax->dev; |
| int rc; |
| |
| device_lock_assert(dax_region->dev); |
| |
| if (dev_WARN_ONCE(dev, !size, "deletion is handled by dev_dax_shrink\n")) |
| return -EINVAL; |
| |
| rc = adjust_resource(res, range->start, size); |
| if (rc) |
| return rc; |
| |
| *range = (struct range) { |
| .start = range->start, |
| .end = range->start + size - 1, |
| }; |
| |
| dev_dbg(dev, "%s range[%d]: %#llx:%#llx\n", is_shrink ? "shrink" : "extend", |
| last_range, (unsigned long long) range->start, |
| (unsigned long long) range->end); |
| |
| return 0; |
| } |
| |
| static ssize_t size_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| unsigned long long size; |
| |
| device_lock(dev); |
| size = dev_dax_size(dev_dax); |
| device_unlock(dev); |
| |
| return sprintf(buf, "%llu\n", size); |
| } |
| |
| static bool alloc_is_aligned(struct dev_dax *dev_dax, resource_size_t size) |
| { |
| /* |
| * The minimum mapping granularity for a device instance is a |
| * single subsection, unless the arch says otherwise. |
| */ |
| return IS_ALIGNED(size, max_t(unsigned long, dev_dax->align, memremap_compat_align())); |
| } |
| |
| static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size) |
| { |
| resource_size_t to_shrink = dev_dax_size(dev_dax) - size; |
| struct dax_region *dax_region = dev_dax->region; |
| struct device *dev = &dev_dax->dev; |
| int i; |
| |
| for (i = dev_dax->nr_range - 1; i >= 0; i--) { |
| struct range *range = &dev_dax->ranges[i].range; |
| struct dax_mapping *mapping = dev_dax->ranges[i].mapping; |
| struct resource *adjust = NULL, *res; |
| resource_size_t shrink; |
| |
| shrink = min_t(u64, to_shrink, range_len(range)); |
| if (shrink >= range_len(range)) { |
| devm_release_action(dax_region->dev, |
| unregister_dax_mapping, &mapping->dev); |
| trim_dev_dax_range(dev_dax); |
| to_shrink -= shrink; |
| if (!to_shrink) |
| break; |
| continue; |
| } |
| |
| for_each_dax_region_resource(dax_region, res) |
| if (strcmp(res->name, dev_name(dev)) == 0 |
| && res->start == range->start) { |
| adjust = res; |
| break; |
| } |
| |
| if (dev_WARN_ONCE(dev, !adjust || i != dev_dax->nr_range - 1, |
| "failed to find matching resource\n")) |
| return -ENXIO; |
| return adjust_dev_dax_range(dev_dax, adjust, range_len(range) |
| - shrink); |
| } |
| return 0; |
| } |
| |
| /* |
| * Only allow adjustments that preserve the relative pgoff of existing |
| * allocations. I.e. the dev_dax->ranges array is ordered by increasing pgoff. |
| */ |
| static bool adjust_ok(struct dev_dax *dev_dax, struct resource *res) |
| { |
| struct dev_dax_range *last; |
| int i; |
| |
| if (dev_dax->nr_range == 0) |
| return false; |
| if (strcmp(res->name, dev_name(&dev_dax->dev)) != 0) |
| return false; |
| last = &dev_dax->ranges[dev_dax->nr_range - 1]; |
| if (last->range.start != res->start || last->range.end != res->end) |
| return false; |
| for (i = 0; i < dev_dax->nr_range - 1; i++) { |
| struct dev_dax_range *dax_range = &dev_dax->ranges[i]; |
| |
| if (dax_range->pgoff > last->pgoff) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static ssize_t dev_dax_resize(struct dax_region *dax_region, |
| struct dev_dax *dev_dax, resource_size_t size) |
| { |
| resource_size_t avail = dax_region_avail_size(dax_region), to_alloc; |
| resource_size_t dev_size = dev_dax_size(dev_dax); |
| struct resource *region_res = &dax_region->res; |
| struct device *dev = &dev_dax->dev; |
| struct resource *res, *first; |
| resource_size_t alloc = 0; |
| int rc; |
| |
| if (dev->driver) |
| return -EBUSY; |
| if (size == dev_size) |
| return 0; |
| if (size > dev_size && size - dev_size > avail) |
| return -ENOSPC; |
| if (size < dev_size) |
| return dev_dax_shrink(dev_dax, size); |
| |
| to_alloc = size - dev_size; |
| if (dev_WARN_ONCE(dev, !alloc_is_aligned(dev_dax, to_alloc), |
| "resize of %pa misaligned\n", &to_alloc)) |
| return -ENXIO; |
| |
| /* |
| * Expand the device into the unused portion of the region. This |
| * may involve adjusting the end of an existing resource, or |
| * allocating a new resource. |
| */ |
| retry: |
| first = region_res->child; |
| if (!first) |
| return alloc_dev_dax_range(dev_dax, dax_region->res.start, to_alloc); |
| |
| rc = -ENOSPC; |
| for (res = first; res; res = res->sibling) { |
| struct resource *next = res->sibling; |
| |
| /* space at the beginning of the region */ |
| if (res == first && res->start > dax_region->res.start) { |
| alloc = min(res->start - dax_region->res.start, to_alloc); |
| rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, alloc); |
| break; |
| } |
| |
| alloc = 0; |
| /* space between allocations */ |
| if (next && next->start > res->end + 1) |
| alloc = min(next->start - (res->end + 1), to_alloc); |
| |
| /* space at the end of the region */ |
| if (!alloc && !next && res->end < region_res->end) |
| alloc = min(region_res->end - res->end, to_alloc); |
| |
| if (!alloc) |
| continue; |
| |
| if (adjust_ok(dev_dax, res)) { |
| rc = adjust_dev_dax_range(dev_dax, res, resource_size(res) + alloc); |
| break; |
| } |
| rc = alloc_dev_dax_range(dev_dax, res->end + 1, alloc); |
| break; |
| } |
| if (rc) |
| return rc; |
| to_alloc -= alloc; |
| if (to_alloc) |
| goto retry; |
| return 0; |
| } |
| |
| static ssize_t size_store(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| ssize_t rc; |
| unsigned long long val; |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| struct dax_region *dax_region = dev_dax->region; |
| |
| rc = kstrtoull(buf, 0, &val); |
| if (rc) |
| return rc; |
| |
| if (!alloc_is_aligned(dev_dax, val)) { |
| dev_dbg(dev, "%s: size: %lld misaligned\n", __func__, val); |
| return -EINVAL; |
| } |
| |
| device_lock(dax_region->dev); |
| if (!dax_region->dev->driver) { |
| device_unlock(dax_region->dev); |
| return -ENXIO; |
| } |
| device_lock(dev); |
| rc = dev_dax_resize(dax_region, dev_dax, val); |
| device_unlock(dev); |
| device_unlock(dax_region->dev); |
| |
| return rc == 0 ? len : rc; |
| } |
| static DEVICE_ATTR_RW(size); |
| |
| static ssize_t range_parse(const char *opt, size_t len, struct range *range) |
| { |
| unsigned long long addr = 0; |
| char *start, *end, *str; |
| ssize_t rc = -EINVAL; |
| |
| str = kstrdup(opt, GFP_KERNEL); |
| if (!str) |
| return rc; |
| |
| end = str; |
| start = strsep(&end, "-"); |
| if (!start || !end) |
| goto err; |
| |
| rc = kstrtoull(start, 16, &addr); |
| if (rc) |
| goto err; |
| range->start = addr; |
| |
| rc = kstrtoull(end, 16, &addr); |
| if (rc) |
| goto err; |
| range->end = addr; |
| |
| err: |
| kfree(str); |
| return rc; |
| } |
| |
| static ssize_t mapping_store(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| struct dax_region *dax_region = dev_dax->region; |
| size_t to_alloc; |
| struct range r; |
| ssize_t rc; |
| |
| rc = range_parse(buf, len, &r); |
| if (rc) |
| return rc; |
| |
| rc = -ENXIO; |
| device_lock(dax_region->dev); |
| if (!dax_region->dev->driver) { |
| device_unlock(dax_region->dev); |
| return rc; |
| } |
| device_lock(dev); |
| |
| to_alloc = range_len(&r); |
| if (alloc_is_aligned(dev_dax, to_alloc)) |
| rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc); |
| device_unlock(dev); |
| device_unlock(dax_region->dev); |
| |
| return rc == 0 ? len : rc; |
| } |
| static DEVICE_ATTR_WO(mapping); |
| |
| static ssize_t align_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| |
| return sprintf(buf, "%d\n", dev_dax->align); |
| } |
| |
| static ssize_t dev_dax_validate_align(struct dev_dax *dev_dax) |
| { |
| struct device *dev = &dev_dax->dev; |
| int i; |
| |
| for (i = 0; i < dev_dax->nr_range; i++) { |
| size_t len = range_len(&dev_dax->ranges[i].range); |
| |
| if (!alloc_is_aligned(dev_dax, len)) { |
| dev_dbg(dev, "%s: align %u invalid for range %d\n", |
| __func__, dev_dax->align, i); |
| return -EINVAL; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static ssize_t align_store(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| struct dax_region *dax_region = dev_dax->region; |
| unsigned long val, align_save; |
| ssize_t rc; |
| |
| rc = kstrtoul(buf, 0, &val); |
| if (rc) |
| return -ENXIO; |
| |
| if (!dax_align_valid(val)) |
| return -EINVAL; |
| |
| device_lock(dax_region->dev); |
| if (!dax_region->dev->driver) { |
| device_unlock(dax_region->dev); |
| return -ENXIO; |
| } |
| |
| device_lock(dev); |
| if (dev->driver) { |
| rc = -EBUSY; |
| goto out_unlock; |
| } |
| |
| align_save = dev_dax->align; |
| dev_dax->align = val; |
| rc = dev_dax_validate_align(dev_dax); |
| if (rc) |
| dev_dax->align = align_save; |
| out_unlock: |
| device_unlock(dev); |
| device_unlock(dax_region->dev); |
| return rc == 0 ? len : rc; |
| } |
| static DEVICE_ATTR_RW(align); |
| |
| static int dev_dax_target_node(struct dev_dax *dev_dax) |
| { |
| struct dax_region *dax_region = dev_dax->region; |
| |
| return dax_region->target_node; |
| } |
| |
| static ssize_t target_node_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| |
| return sprintf(buf, "%d\n", dev_dax_target_node(dev_dax)); |
| } |
| static DEVICE_ATTR_RO(target_node); |
| |
| static ssize_t resource_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| struct dax_region *dax_region = dev_dax->region; |
| unsigned long long start; |
| |
| if (dev_dax->nr_range < 1) |
| start = dax_region->res.start; |
| else |
| start = dev_dax->ranges[0].range.start; |
| |
| return sprintf(buf, "%#llx\n", start); |
| } |
| static DEVICE_ATTR(resource, 0400, resource_show, NULL); |
| |
| static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| /* |
| * We only ever expect to handle device-dax instances, i.e. the |
| * @type argument to MODULE_ALIAS_DAX_DEVICE() is always zero |
| */ |
| return sprintf(buf, DAX_DEVICE_MODALIAS_FMT "\n", 0); |
| } |
| static DEVICE_ATTR_RO(modalias); |
| |
| static ssize_t numa_node_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", dev_to_node(dev)); |
| } |
| static DEVICE_ATTR_RO(numa_node); |
| |
| static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) |
| { |
| struct device *dev = container_of(kobj, struct device, kobj); |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| struct dax_region *dax_region = dev_dax->region; |
| |
| if (a == &dev_attr_target_node.attr && dev_dax_target_node(dev_dax) < 0) |
| return 0; |
| if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA)) |
| return 0; |
| if (a == &dev_attr_mapping.attr && is_static(dax_region)) |
| return 0; |
| if ((a == &dev_attr_align.attr || |
| a == &dev_attr_size.attr) && is_static(dax_region)) |
| return 0444; |
| return a->mode; |
| } |
| |
| static struct attribute *dev_dax_attributes[] = { |
| &dev_attr_modalias.attr, |
| &dev_attr_size.attr, |
| &dev_attr_mapping.attr, |
| &dev_attr_target_node.attr, |
| &dev_attr_align.attr, |
| &dev_attr_resource.attr, |
| &dev_attr_numa_node.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group dev_dax_attribute_group = { |
| .attrs = dev_dax_attributes, |
| .is_visible = dev_dax_visible, |
| }; |
| |
| static const struct attribute_group *dax_attribute_groups[] = { |
| &dev_dax_attribute_group, |
| NULL, |
| }; |
| |
| static void dev_dax_release(struct device *dev) |
| { |
| struct dev_dax *dev_dax = to_dev_dax(dev); |
| struct dax_device *dax_dev = dev_dax->dax_dev; |
| |
| put_dax(dax_dev); |
| free_dev_dax_id(dev_dax); |
| kfree(dev_dax->pgmap); |
| kfree(dev_dax); |
| } |
| |
| static const struct device_type dev_dax_type = { |
| .release = dev_dax_release, |
| .groups = dax_attribute_groups, |
| }; |
| |
| struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) |
| { |
| struct dax_region *dax_region = data->dax_region; |
| struct device *parent = dax_region->dev; |
| struct dax_device *dax_dev; |
| struct dev_dax *dev_dax; |
| struct inode *inode; |
| struct device *dev; |
| int rc; |
| |
| dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL); |
| if (!dev_dax) |
| return ERR_PTR(-ENOMEM); |
| |
| dev_dax->region = dax_region; |
| if (is_static(dax_region)) { |
| if (dev_WARN_ONCE(parent, data->id < 0, |
| "dynamic id specified to static region\n")) { |
| rc = -EINVAL; |
| goto err_id; |
| } |
| |
| dev_dax->id = data->id; |
| } else { |
| if (dev_WARN_ONCE(parent, data->id >= 0, |
| "static id specified to dynamic region\n")) { |
| rc = -EINVAL; |
| goto err_id; |
| } |
| |
| rc = alloc_dev_dax_id(dev_dax); |
| if (rc < 0) |
| goto err_id; |
| } |
| |
| dev = &dev_dax->dev; |
| device_initialize(dev); |
| dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id); |
| |
| rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, data->size); |
| if (rc) |
| goto err_range; |
| |
| if (data->pgmap) { |
| dev_WARN_ONCE(parent, !is_static(dax_region), |
| "custom dev_pagemap requires a static dax_region\n"); |
| |
| dev_dax->pgmap = kmemdup(data->pgmap, |
| sizeof(struct dev_pagemap), GFP_KERNEL); |
| if (!dev_dax->pgmap) { |
| rc = -ENOMEM; |
| goto err_pgmap; |
| } |
| } |
| |
| /* |
| * No dax_operations since there is no access to this device outside of |
| * mmap of the resulting character device. |
| */ |
| dax_dev = alloc_dax(dev_dax, NULL); |
| if (IS_ERR(dax_dev)) { |
| rc = PTR_ERR(dax_dev); |
| goto err_alloc_dax; |
| } |
| set_dax_synchronous(dax_dev); |
| set_dax_nocache(dax_dev); |
| set_dax_nomc(dax_dev); |
| |
| /* a device_dax instance is dead while the driver is not attached */ |
| kill_dax(dax_dev); |
| |
| dev_dax->dax_dev = dax_dev; |
| dev_dax->target_node = dax_region->target_node; |
| dev_dax->align = dax_region->align; |
| ida_init(&dev_dax->ida); |
| |
| inode = dax_inode(dax_dev); |
| dev->devt = inode->i_rdev; |
| dev->bus = &dax_bus_type; |
| dev->parent = parent; |
| dev->type = &dev_dax_type; |
| |
| rc = device_add(dev); |
| if (rc) { |
| kill_dev_dax(dev_dax); |
| put_device(dev); |
| return ERR_PTR(rc); |
| } |
| |
| rc = devm_add_action_or_reset(dax_region->dev, unregister_dev_dax, dev); |
| if (rc) |
| return ERR_PTR(rc); |
| |
| /* register mapping device for the initial allocation range */ |
| if (dev_dax->nr_range && range_len(&dev_dax->ranges[0].range)) { |
| rc = devm_register_dax_mapping(dev_dax, 0); |
| if (rc) |
| return ERR_PTR(rc); |
| } |
| |
| return dev_dax; |
| |
| err_alloc_dax: |
| kfree(dev_dax->pgmap); |
| err_pgmap: |
| free_dev_dax_ranges(dev_dax); |
| err_range: |
| free_dev_dax_id(dev_dax); |
| err_id: |
| kfree(dev_dax); |
| |
| return ERR_PTR(rc); |
| } |
| EXPORT_SYMBOL_GPL(devm_create_dev_dax); |
| |
| static int match_always_count; |
| |
| int __dax_driver_register(struct dax_device_driver *dax_drv, |
| struct module *module, const char *mod_name) |
| { |
| struct device_driver *drv = &dax_drv->drv; |
| int rc = 0; |
| |
| /* |
| * dax_bus_probe() calls dax_drv->probe() unconditionally. |
| * So better be safe than sorry and ensure it is provided. |
| */ |
| if (!dax_drv->probe) |
| return -EINVAL; |
| |
| INIT_LIST_HEAD(&dax_drv->ids); |
| drv->owner = module; |
| drv->name = mod_name; |
| drv->mod_name = mod_name; |
| drv->bus = &dax_bus_type; |
| |
| /* there can only be one default driver */ |
| mutex_lock(&dax_bus_lock); |
| match_always_count += dax_drv->match_always; |
| if (match_always_count > 1) { |
| match_always_count--; |
| WARN_ON(1); |
| rc = -EINVAL; |
| } |
| mutex_unlock(&dax_bus_lock); |
| if (rc) |
| return rc; |
| |
| rc = driver_register(drv); |
| if (rc && dax_drv->match_always) { |
| mutex_lock(&dax_bus_lock); |
| match_always_count -= dax_drv->match_always; |
| mutex_unlock(&dax_bus_lock); |
| } |
| |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(__dax_driver_register); |
| |
| void dax_driver_unregister(struct dax_device_driver *dax_drv) |
| { |
| struct device_driver *drv = &dax_drv->drv; |
| struct dax_id *dax_id, *_id; |
| |
| mutex_lock(&dax_bus_lock); |
| match_always_count -= dax_drv->match_always; |
| list_for_each_entry_safe(dax_id, _id, &dax_drv->ids, list) { |
| list_del(&dax_id->list); |
| kfree(dax_id); |
| } |
| mutex_unlock(&dax_bus_lock); |
| driver_unregister(drv); |
| } |
| EXPORT_SYMBOL_GPL(dax_driver_unregister); |
| |
| int __init dax_bus_init(void) |
| { |
| return bus_register(&dax_bus_type); |
| } |
| |
| void __exit dax_bus_exit(void) |
| { |
| bus_unregister(&dax_bus_type); |
| } |