While this information is available by looking at the nvdimm parent device that may not always be the case when/if we add support for other memory regions. Tooling should not depend on walking a given ancestor topology that is not guaranteed by the device's class. For example, a device-dax instance will always have a dax_region parent, but it may not always have a libnvdimm "dax" device as a grandparent.
Signed-off-by: Dan Williams <dan.j.willi...@intel.com> --- drivers/dax/dax.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c index cc7c4aa4bcc2..da2962b6f8de 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/dax.c @@ -111,8 +111,61 @@ static ssize_t available_size_show(struct device *dev, } static DEVICE_ATTR_RO(available_size); +static ssize_t id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region; + ssize_t rc = -ENXIO; + + device_lock(dev); + dax_region = dev_get_drvdata(dev); + if (dax_region) + rc = sprintf(buf, "%d\n", dax_region->id); + device_unlock(dev); + + return rc; +} +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; + ssize_t rc = -ENXIO; + + device_lock(dev); + dax_region = dev_get_drvdata(dev); + if (dax_region) + rc = sprintf(buf, "%llu\n", (unsigned long long) + resource_size(&dax_region->res)); + device_unlock(dev); + + return rc; +} +static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, + region_size_show, NULL); + +static ssize_t align_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region; + ssize_t rc = -ENXIO; + + device_lock(dev); + dax_region = dev_get_drvdata(dev); + if (dax_region) + rc = sprintf(buf, "%u\n", dax_region->align); + device_unlock(dev); + + return rc; +} +static DEVICE_ATTR_RO(align); + static struct attribute *dax_region_attributes[] = { &dev_attr_available_size.attr, + &dev_attr_region_size.attr, + &dev_attr_align.attr, + &dev_attr_id.attr, NULL, };