{
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;
+ struct range *range = &dev_dax->range;
+ int rc;
+
+ if (range_len(range) == 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 dax_drv->probe(dev_dax);
+ return 0;
}
static int dax_bus_remove(struct device *dev)
}
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 free_dev_dax_range(struct dev_dax *dev_dax)
+{
+ struct dax_region *dax_region = dev_dax->region;
+ struct range *range = &dev_dax->range;
+
+ device_lock_assert(dax_region->dev);
+ if (range_len(range))
+ __release_region(&dax_region->res, range->start,
+ range_len(range));
+}
+
+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_range(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 || range_len(&dev_dax->range))
+ 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) && a == &dev_attr_available_size.attr)
- return 0;
+ 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;
}
&dev_attr_available_size.attr,
&dev_attr_region_size.attr,
&dev_attr_align.attr,
+ &dev_attr_create.attr,
+ &dev_attr_seed.attr,
+ &dev_attr_delete.attr,
&dev_attr_id.attr,
NULL,
};
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 = res->start,
.end = res->end,
device_lock_assert(dax_region->dev);
+ /* handle the seed alloc special case */
+ if (!size) {
+ dev_dax->range = (struct range) {
+ .start = res->start,
+ .end = res->start - 1,
+ };
+ return 0;
+ }
+
/* TODO: handle multiple allocations per region */
if (res->child)
return -ENOMEM;
NULL,
};
-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 free_dev_dax_range(struct dev_dax *dev_dax)
-{
- struct dax_region *dax_region = dev_dax->region;
- struct range *range = &dev_dax->range;
-
- device_lock_assert(dax_region->dev);
- __release_region(&dax_region->res, range->start, range_len(range));
-}
-
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;
- dax_region_put(dax_region);
put_dax(dax_dev);
+ free_dev_dax_id(dev_dax);
+ dax_region_put(dax_region);
kfree(dev_dax->pgmap);
kfree(dev_dax);
}
.groups = dax_attribute_groups,
};
-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_range(dev_dax);
- device_del(dev);
- put_device(dev);
-}
-
struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
{
struct dax_region *dax_region = data->dax_region;
struct device *dev;
int rc;
- if (data->id < 0)
- return ERR_PTR(-EINVAL);
-
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, data->id);
+ dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
rc = alloc_dev_dax_range(dev_dax, data->size);
if (rc)
err_pgmap:
free_dev_dax_range(dev_dax);
err_range:
+ free_dev_dax_id(dev_dax);
+err_id:
kfree(dev_dax);
return ERR_PTR(rc);
projects / kernel.git / commitdiff