On 7/12/20 5:28 PM, Dan Williams wrote:
> In support of interrogating the physical address layout of a device with
> dis-contiguous ranges, introduce a sysfs directory with 'start', 'end',
> and 'page_offset' attributes. The alternative is trying to parse
> /proc/iomem, and that file will not reflect the extent layout until the
> device is enabled.
>
> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
> drivers/dax/bus.c | 191 +++++++++++++++++++++++++++++++++++++++++++++
> drivers/dax/dax-private.h | 14 +++
> 2 files changed, 203 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index f342e36c69a1..8b6c4ddc5f42 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -579,6 +579,167 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
> }
> 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 < 1) {
^^^^^^^^^^^^^^^^^^^^^ it's 'mapping->range_id < 0'
Otherwise 'mapping0' sysfs entries won't work.
Disabled ranges use id -1.
Joao
