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authorVishal Verma <vishal.l.verma@intel.com>2019-06-21 02:40:38 +0200
committerDan Williams <dan.j.williams@intel.com>2019-06-21 02:40:00 +0200
commit40cdc60ac16a42eb4e013f84d0e7aa1d6ee060d3 (patch)
tree1dc50d892f9b1586639ed1ae53b001cca21350a6
parentLinux 5.2-rc5 (diff)
downloadlinux-40cdc60ac16a42eb4e013f84d0e7aa1d6ee060d3.tar.xz
linux-40cdc60ac16a42eb4e013f84d0e7aa1d6ee060d3.zip
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: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/dax/bus.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 2109cfe80219..2f3c42ca416a 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -295,6 +295,22 @@ static ssize_t target_node_show(struct device *dev,
}
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,
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)
return 0;
+ if (a == &dev_attr_resource.attr)
+ return 0400;
return a->mode;
}
@@ -320,6 +338,7 @@ static struct attribute *dev_dax_attributes[] = {
&dev_attr_modalias.attr,
&dev_attr_size.attr,
&dev_attr_target_node.attr,
+ &dev_attr_resource.attr,
NULL,
};