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- // 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 struct class *dax_class;
- 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
- /* nothing to remove */;
- } else if (action == ID_REMOVE) {
- list_del(&dax_id->list);
- kfree(dax_id);
- } else
- /* dax_id already added */;
- 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 bool is_static(struct dax_region *dax_region)
- {
- return (dax_region->res.flags & IORESOURCE_DAX_STATIC) != 0;
- }
- 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 int 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);
- return 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);
- }
- 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);
- free_dev_dax_ranges(dev_dax);
- device_del(dev);
- put_device(dev);
- }
- /* a return value >= 0 indicates this invocation invalidated the id */
- static int __free_dev_dax_id(struct dev_dax *dev_dax)
- {
- struct dax_region *dax_region = dev_dax->region;
- struct device *dev = &dev_dax->dev;
- int rc = dev_dax->id;
- device_lock_assert(dev);
- if (is_static(dax_region) || dev_dax->id < 0)
- return -1;
- ida_free(&dax_region->ida, dev_dax->id);
- 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 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_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);
- 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 dev_dax *dev_dax = to_dev_dax(dev->parent);
- ida_free(&dev_dax->ida, mapping->id);
- kfree(mapping);
- }
- 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;
- 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;
- }
- ranges = krealloc(dev_dax->ranges, sizeof(*ranges)
- * (dev_dax->nr_range + 1), GFP_KERNEL);
- if (!ranges)
- return -ENOMEM;
- alloc = __request_region(res, start, size, dev_name(dev), 0);
- if (!alloc) {
- /*
- * If this was an empty set of ranges nothing else
- * will release @ranges, so do it now.
- */
- if (!dev_dax->nr_range) {
- kfree(ranges);
- ranges = NULL;
- }
- dev_dax->ranges = ranges;
- 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)
- {
- resource_size_t dev_size = dev_dax_size(dev_dax);
- struct device *dev = &dev_dax->dev;
- int i;
- if (dev_size > 0 && !alloc_is_aligned(dev_dax, dev_size)) {
- dev_dbg(dev, "%s: align %u invalid for size %pa\n",
- __func__, dev_dax->align, &dev_size);
- return -EINVAL;
- }
- 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_region *dax_region = dev_dax->region;
- struct dax_device *dax_dev = dev_dax->dax_dev;
- put_dax(dax_dev);
- free_dev_dax_id(dev_dax);
- dax_region_put(dax_region);
- 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);
- 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 = ida_alloc(&dax_region->ida, GFP_KERNEL);
- if (rc < 0)
- goto err_id;
- dev_dax->id = rc;
- }
- dev_dax->region = dax_region;
- 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 'host' or 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, NULL, DAXDEV_F_SYNC);
- if (IS_ERR(dax_dev)) {
- rc = PTR_ERR(dax_dev);
- goto err_alloc_dax;
- }
- /* 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);
- kref_get(&dax_region->kref);
- inode = dax_inode(dax_dev);
- dev->devt = inode->i_rdev;
- if (data->subsys == DEV_DAX_BUS)
- dev->bus = &dax_bus_type;
- else
- dev->class = dax_class;
- 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;
- 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;
- return driver_register(drv);
- }
- 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)
- {
- int rc;
- if (IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT)) {
- dax_class = class_create(THIS_MODULE, "dax");
- if (IS_ERR(dax_class))
- return PTR_ERR(dax_class);
- }
- rc = bus_register(&dax_bus_type);
- if (rc)
- class_destroy(dax_class);
- return rc;
- }
- void __exit dax_bus_exit(void)
- {
- bus_unregister(&dax_bus_type);
- class_destroy(dax_class);
- }
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