+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);
+