Commit 40cdc60a authored by Vishal Verma's avatar Vishal Verma Committed by Dan Williams
Browse files

device-dax: Add a 'resource' attribute 



device-dax based devices were missing a 'resource' attribute to indicate
the physical address range contributed by the device in question. This
information is desirable to userspace tooling that may want to use the
dax device as system-ram, and wants to selectively hotplug and online
the memory blocks associated with a given device.

Without this, the tooling would have to parse /proc/iomem for the memory
ranges contributed by dax devices, which can be a workaround, but it is
far easier to provide this information in the sysfs hierarchy.

Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 9e0babf2

drivers/dax/bus.c

+19 −0
Original line number Original line Diff line number Diff line
@@ -295,6 +295,22 @@ static ssize_t target_node_show(struct device *dev, 
}

}

static DEVICE_ATTR_RO(target_node);

static DEVICE_ATTR_RO(target_node);





static unsigned long long dev_dax_resource(struct dev_dax *dev_dax)

{

	struct dax_region *dax_region = dev_dax->region;



	return dax_region->res.start;

}



static ssize_t resource_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct dev_dax *dev_dax = to_dev_dax(dev);



	return sprintf(buf, "%#llx\n", dev_dax_resource(dev_dax));

}

static DEVICE_ATTR_RO(resource);



static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,

		char *buf)

		char *buf)

{

{
@@ -313,6 +329,8 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) 




	if (a == &dev_attr_target_node.attr && dev_dax_target_node(dev_dax) < 0)

	if (a == &dev_attr_target_node.attr && dev_dax_target_node(dev_dax) < 0)

		return 0;

		return 0;

	if (a == &dev_attr_resource.attr)

		return 0400;

	return a->mode;

	return a->mode;

}

}
@@ -320,6 +338,7 @@ static struct attribute *dev_dax_attributes[] = { 
	&dev_attr_modalias.attr,

	&dev_attr_modalias.attr,

	&dev_attr_size.attr,

	&dev_attr_size.attr,

	&dev_attr_target_node.attr,

	&dev_attr_target_node.attr,

	&dev_attr_resource.attr,

	NULL,

	NULL,

};

};

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