[01/16] libnvdimm: Move attribute groups to device type
diff mbox series

Message ID 157309900111.1582359.2445687530383470348.stgit@dwillia2-desk3.amr.corp.intel.com
State Superseded
Headers show
Series
  • Memory Hierarchy: Enable target node lookups for reserved memory
Related show

Commit Message

Dan Williams Nov. 7, 2019, 3:56 a.m. UTC
Statically initialize the attribute groups for each libnvdimm
device_type. This is a preparation step for removing unnecessary exports
of attributes that can be included in the device_type by default.

Also take the opportunity to mark 'struct device_type' instances const.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/btt_devs.c       |   24 +++++++-------
 drivers/nvdimm/dax_devs.c       |   27 ++++++---------
 drivers/nvdimm/namespace_devs.c |   68 +++++++++++++++++++++------------------
 drivers/nvdimm/nd.h             |    2 +
 drivers/nvdimm/pfn_devs.c       |   28 ++++++++--------
 5 files changed, 73 insertions(+), 76 deletions(-)

Comments

Aneesh Kumar K.V Nov. 12, 2019, 11:28 a.m. UTC | #1
Dan Williams <dan.j.williams@intel.com> writes:

> Statically initialize the attribute groups for each libnvdimm
> device_type. This is a preparation step for removing unnecessary exports
> of attributes that can be included in the device_type by default.
>
> Also take the opportunity to mark 'struct device_type' instances const.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/nvdimm/btt_devs.c       |   24 +++++++-------
>  drivers/nvdimm/dax_devs.c       |   27 ++++++---------
>  drivers/nvdimm/namespace_devs.c |   68 +++++++++++++++++++++------------------
>  drivers/nvdimm/nd.h             |    2 +
>  drivers/nvdimm/pfn_devs.c       |   28 ++++++++--------
>  5 files changed, 73 insertions(+), 76 deletions(-)
>
> diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
> index 3508a79110c7..05feb97e11ce 100644
> --- a/drivers/nvdimm/btt_devs.c
> +++ b/drivers/nvdimm/btt_devs.c
> @@ -25,17 +25,6 @@ static void nd_btt_release(struct device *dev)
>  	kfree(nd_btt);
>  }
>  
> -static struct device_type nd_btt_device_type = {
> -	.name = "nd_btt",
> -	.release = nd_btt_release,
> -};
> -
> -bool is_nd_btt(struct device *dev)
> -{
> -	return dev->type == &nd_btt_device_type;
> -}
> -EXPORT_SYMBOL(is_nd_btt);
> -
>  struct nd_btt *to_nd_btt(struct device *dev)
>  {
>  	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
> @@ -178,6 +167,18 @@ static const struct attribute_group *nd_btt_attribute_groups[] = {
>  	NULL,
>  };
>  
> +static const struct device_type nd_btt_device_type = {
> +	.name = "nd_btt",
> +	.release = nd_btt_release,
> +	.groups = nd_btt_attribute_groups,
> +};
> +
> +bool is_nd_btt(struct device *dev)
> +{
> +	return dev->type == &nd_btt_device_type;
> +}
> +EXPORT_SYMBOL(is_nd_btt);
> +
>  static struct device *__nd_btt_create(struct nd_region *nd_region,
>  		unsigned long lbasize, u8 *uuid,
>  		struct nd_namespace_common *ndns)
> @@ -204,7 +205,6 @@ static struct device *__nd_btt_create(struct nd_region *nd_region,
>  	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
>  	dev->parent = &nd_region->dev;
>  	dev->type = &nd_btt_device_type;
> -	dev->groups = nd_btt_attribute_groups;
>  	device_initialize(&nd_btt->dev);
>  	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
>  		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
> diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
> index 6d22b0f83b3b..99965077bac4 100644
> --- a/drivers/nvdimm/dax_devs.c
> +++ b/drivers/nvdimm/dax_devs.c
> @@ -23,17 +23,6 @@ static void nd_dax_release(struct device *dev)
>  	kfree(nd_dax);
>  }
>  
> -static struct device_type nd_dax_device_type = {
> -	.name = "nd_dax",
> -	.release = nd_dax_release,
> -};
> -
> -bool is_nd_dax(struct device *dev)
> -{
> -	return dev ? dev->type == &nd_dax_device_type : false;
> -}
> -EXPORT_SYMBOL(is_nd_dax);
> -
>  struct nd_dax *to_nd_dax(struct device *dev)
>  {
>  	struct nd_dax *nd_dax = container_of(dev, struct nd_dax, nd_pfn.dev);
> @@ -43,13 +32,18 @@ struct nd_dax *to_nd_dax(struct device *dev)
>  }
>  EXPORT_SYMBOL(to_nd_dax);
>  
> -static const struct attribute_group *nd_dax_attribute_groups[] = {
> -	&nd_pfn_attribute_group,
> -	&nd_device_attribute_group,
> -	&nd_numa_attribute_group,
> -	NULL,
> +static const struct device_type nd_dax_device_type = {
> +	.name = "nd_dax",
> +	.release = nd_dax_release,
> +	.groups = nd_pfn_attribute_groups,
>  };
>  
> +bool is_nd_dax(struct device *dev)
> +{
> +	return dev ? dev->type == &nd_dax_device_type : false;
> +}
> +EXPORT_SYMBOL(is_nd_dax);
> +
>  static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
>  {
>  	struct nd_pfn *nd_pfn;
> @@ -69,7 +63,6 @@ static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
>  
>  	dev = &nd_pfn->dev;
>  	dev_set_name(dev, "dax%d.%d", nd_region->id, nd_pfn->id);
> -	dev->groups = nd_dax_attribute_groups;
>  	dev->type = &nd_dax_device_type;
>  	dev->parent = &nd_region->dev;
>  
> diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
> index cca0a3ba1d2c..37471a272c1a 100644
> --- a/drivers/nvdimm/namespace_devs.c
> +++ b/drivers/nvdimm/namespace_devs.c
> @@ -44,35 +44,9 @@ static void namespace_blk_release(struct device *dev)
>  	kfree(nsblk);
>  }
>  
> -static const struct device_type namespace_io_device_type = {
> -	.name = "nd_namespace_io",
> -	.release = namespace_io_release,
> -};
> -
> -static const struct device_type namespace_pmem_device_type = {
> -	.name = "nd_namespace_pmem",
> -	.release = namespace_pmem_release,
> -};
> -
> -static const struct device_type namespace_blk_device_type = {
> -	.name = "nd_namespace_blk",
> -	.release = namespace_blk_release,
> -};
> -
> -static bool is_namespace_pmem(const struct device *dev)
> -{
> -	return dev ? dev->type == &namespace_pmem_device_type : false;
> -}
> -
> -static bool is_namespace_blk(const struct device *dev)
> -{
> -	return dev ? dev->type == &namespace_blk_device_type : false;
> -}
> -
> -static bool is_namespace_io(const struct device *dev)
> -{
> -	return dev ? dev->type == &namespace_io_device_type : false;
> -}
> +static bool is_namespace_pmem(const struct device *dev);
> +static bool is_namespace_blk(const struct device *dev);
> +static bool is_namespace_io(const struct device *dev);
>  
>  static int is_uuid_busy(struct device *dev, void *data)
>  {
> @@ -1680,6 +1654,39 @@ static const struct attribute_group *nd_namespace_attribute_groups[] = {
>  	NULL,
>  };
>  
> +static const struct device_type namespace_io_device_type = {
> +	.name = "nd_namespace_io",
> +	.release = namespace_io_release,
> +	.groups = nd_namespace_attribute_groups,
> +};
> +
> +static const struct device_type namespace_pmem_device_type = {
> +	.name = "nd_namespace_pmem",
> +	.release = namespace_pmem_release,
> +	.groups = nd_namespace_attribute_groups,
> +};
> +
> +static const struct device_type namespace_blk_device_type = {
> +	.name = "nd_namespace_blk",
> +	.release = namespace_blk_release,
> +	.groups = nd_namespace_attribute_groups,
> +};
> +
> +static bool is_namespace_pmem(const struct device *dev)
> +{
> +	return dev ? dev->type == &namespace_pmem_device_type : false;
> +}
> +
> +static bool is_namespace_blk(const struct device *dev)
> +{
> +	return dev ? dev->type == &namespace_blk_device_type : false;
> +}
> +
> +static bool is_namespace_io(const struct device *dev)
> +{
> +	return dev ? dev->type == &namespace_io_device_type : false;
> +}
> +
>  struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
>  {
>  	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
> @@ -2078,7 +2085,6 @@ static struct device *nd_namespace_blk_create(struct nd_region *nd_region)
>  	}
>  	dev_set_name(dev, "namespace%d.%d", nd_region->id, nsblk->id);
>  	dev->parent = &nd_region->dev;
> -	dev->groups = nd_namespace_attribute_groups;
>  
>  	return &nsblk->common.dev;
>  }
> @@ -2109,7 +2115,6 @@ static struct device *nd_namespace_pmem_create(struct nd_region *nd_region)
>  		return NULL;
>  	}
>  	dev_set_name(dev, "namespace%d.%d", nd_region->id, nspm->id);
> -	dev->groups = nd_namespace_attribute_groups;
>  	nd_namespace_pmem_set_resource(nd_region, nspm, 0);
>  
>  	return dev;
> @@ -2608,7 +2613,6 @@ int nd_region_register_namespaces(struct nd_region *nd_region, int *err)
>  		if (id < 0)
>  			break;
>  		dev_set_name(dev, "namespace%d.%d", nd_region->id, id);
> -		dev->groups = nd_namespace_attribute_groups;
>  		nd_device_register(dev);
>  	}
>  	if (i)
> diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
> index ee5c04070ef9..5c8b077b3237 100644
> --- a/drivers/nvdimm/nd.h
> +++ b/drivers/nvdimm/nd.h
> @@ -297,7 +297,7 @@ struct device *nd_pfn_create(struct nd_region *nd_region);
>  struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
>  		struct nd_namespace_common *ndns);
>  int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig);
> -extern struct attribute_group nd_pfn_attribute_group;
> +extern const struct attribute_group *nd_pfn_attribute_groups[];
>  #else
>  static inline int nd_pfn_probe(struct device *dev,
>  		struct nd_namespace_common *ndns)
> diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
> index 60d81fae06ee..e809961e2b6f 100644
> --- a/drivers/nvdimm/pfn_devs.c
> +++ b/drivers/nvdimm/pfn_devs.c
> @@ -26,17 +26,6 @@ static void nd_pfn_release(struct device *dev)
>  	kfree(nd_pfn);
>  }
>  
> -static struct device_type nd_pfn_device_type = {
> -	.name = "nd_pfn",
> -	.release = nd_pfn_release,
> -};
> -
> -bool is_nd_pfn(struct device *dev)
> -{
> -	return dev ? dev->type == &nd_pfn_device_type : false;
> -}
> -EXPORT_SYMBOL(is_nd_pfn);
> -
>  struct nd_pfn *to_nd_pfn(struct device *dev)
>  {
>  	struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
> @@ -287,18 +276,30 @@ static umode_t pfn_visible(struct kobject *kobj, struct attribute *a, int n)
>  	return a->mode;
>  }
>  
> -struct attribute_group nd_pfn_attribute_group = {
> +static struct attribute_group nd_pfn_attribute_group = {
>  	.attrs = nd_pfn_attributes,
>  	.is_visible = pfn_visible,
>  };
>  
> -static const struct attribute_group *nd_pfn_attribute_groups[] = {
> +const struct attribute_group *nd_pfn_attribute_groups[] = {
>  	&nd_pfn_attribute_group,
>  	&nd_device_attribute_group,
>  	&nd_numa_attribute_group,
>  	NULL,
>  };
>  
> +static const struct device_type nd_pfn_device_type = {
> +	.name = "nd_pfn",
> +	.release = nd_pfn_release,
> +	.groups = nd_pfn_attribute_groups,
> +};
> +
> +bool is_nd_pfn(struct device *dev)
> +{
> +	return dev ? dev->type == &nd_pfn_device_type : false;
> +}
> +EXPORT_SYMBOL(is_nd_pfn);
> +
>  struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
>  		struct nd_namespace_common *ndns)
>  {
> @@ -337,7 +338,6 @@ static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
>  
>  	dev = &nd_pfn->dev;
>  	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
> -	dev->groups = nd_pfn_attribute_groups;
>  	dev->type = &nd_pfn_device_type;
>  	dev->parent = &nd_region->dev;
>  
> _______________________________________________
> Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
> To unsubscribe send an email to linux-nvdimm-leave@lists.01.org

Patch
diff mbox series

diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index 3508a79110c7..05feb97e11ce 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -25,17 +25,6 @@  static void nd_btt_release(struct device *dev)
 	kfree(nd_btt);
 }
 
-static struct device_type nd_btt_device_type = {
-	.name = "nd_btt",
-	.release = nd_btt_release,
-};
-
-bool is_nd_btt(struct device *dev)
-{
-	return dev->type == &nd_btt_device_type;
-}
-EXPORT_SYMBOL(is_nd_btt);
-
 struct nd_btt *to_nd_btt(struct device *dev)
 {
 	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
@@ -178,6 +167,18 @@  static const struct attribute_group *nd_btt_attribute_groups[] = {
 	NULL,
 };
 
+static const struct device_type nd_btt_device_type = {
+	.name = "nd_btt",
+	.release = nd_btt_release,
+	.groups = nd_btt_attribute_groups,
+};
+
+bool is_nd_btt(struct device *dev)
+{
+	return dev->type == &nd_btt_device_type;
+}
+EXPORT_SYMBOL(is_nd_btt);
+
 static struct device *__nd_btt_create(struct nd_region *nd_region,
 		unsigned long lbasize, u8 *uuid,
 		struct nd_namespace_common *ndns)
@@ -204,7 +205,6 @@  static struct device *__nd_btt_create(struct nd_region *nd_region,
 	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
 	dev->parent = &nd_region->dev;
 	dev->type = &nd_btt_device_type;
-	dev->groups = nd_btt_attribute_groups;
 	device_initialize(&nd_btt->dev);
 	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
 		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 6d22b0f83b3b..99965077bac4 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -23,17 +23,6 @@  static void nd_dax_release(struct device *dev)
 	kfree(nd_dax);
 }
 
-static struct device_type nd_dax_device_type = {
-	.name = "nd_dax",
-	.release = nd_dax_release,
-};
-
-bool is_nd_dax(struct device *dev)
-{
-	return dev ? dev->type == &nd_dax_device_type : false;
-}
-EXPORT_SYMBOL(is_nd_dax);
-
 struct nd_dax *to_nd_dax(struct device *dev)
 {
 	struct nd_dax *nd_dax = container_of(dev, struct nd_dax, nd_pfn.dev);
@@ -43,13 +32,18 @@  struct nd_dax *to_nd_dax(struct device *dev)
 }
 EXPORT_SYMBOL(to_nd_dax);
 
-static const struct attribute_group *nd_dax_attribute_groups[] = {
-	&nd_pfn_attribute_group,
-	&nd_device_attribute_group,
-	&nd_numa_attribute_group,
-	NULL,
+static const struct device_type nd_dax_device_type = {
+	.name = "nd_dax",
+	.release = nd_dax_release,
+	.groups = nd_pfn_attribute_groups,
 };
 
+bool is_nd_dax(struct device *dev)
+{
+	return dev ? dev->type == &nd_dax_device_type : false;
+}
+EXPORT_SYMBOL(is_nd_dax);
+
 static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
 {
 	struct nd_pfn *nd_pfn;
@@ -69,7 +63,6 @@  static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
 
 	dev = &nd_pfn->dev;
 	dev_set_name(dev, "dax%d.%d", nd_region->id, nd_pfn->id);
-	dev->groups = nd_dax_attribute_groups;
 	dev->type = &nd_dax_device_type;
 	dev->parent = &nd_region->dev;
 
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index cca0a3ba1d2c..37471a272c1a 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -44,35 +44,9 @@  static void namespace_blk_release(struct device *dev)
 	kfree(nsblk);
 }
 
-static const struct device_type namespace_io_device_type = {
-	.name = "nd_namespace_io",
-	.release = namespace_io_release,
-};
-
-static const struct device_type namespace_pmem_device_type = {
-	.name = "nd_namespace_pmem",
-	.release = namespace_pmem_release,
-};
-
-static const struct device_type namespace_blk_device_type = {
-	.name = "nd_namespace_blk",
-	.release = namespace_blk_release,
-};
-
-static bool is_namespace_pmem(const struct device *dev)
-{
-	return dev ? dev->type == &namespace_pmem_device_type : false;
-}
-
-static bool is_namespace_blk(const struct device *dev)
-{
-	return dev ? dev->type == &namespace_blk_device_type : false;
-}
-
-static bool is_namespace_io(const struct device *dev)
-{
-	return dev ? dev->type == &namespace_io_device_type : false;
-}
+static bool is_namespace_pmem(const struct device *dev);
+static bool is_namespace_blk(const struct device *dev);
+static bool is_namespace_io(const struct device *dev);
 
 static int is_uuid_busy(struct device *dev, void *data)
 {
@@ -1680,6 +1654,39 @@  static const struct attribute_group *nd_namespace_attribute_groups[] = {
 	NULL,
 };
 
+static const struct device_type namespace_io_device_type = {
+	.name = "nd_namespace_io",
+	.release = namespace_io_release,
+	.groups = nd_namespace_attribute_groups,
+};
+
+static const struct device_type namespace_pmem_device_type = {
+	.name = "nd_namespace_pmem",
+	.release = namespace_pmem_release,
+	.groups = nd_namespace_attribute_groups,
+};
+
+static const struct device_type namespace_blk_device_type = {
+	.name = "nd_namespace_blk",
+	.release = namespace_blk_release,
+	.groups = nd_namespace_attribute_groups,
+};
+
+static bool is_namespace_pmem(const struct device *dev)
+{
+	return dev ? dev->type == &namespace_pmem_device_type : false;
+}
+
+static bool is_namespace_blk(const struct device *dev)
+{
+	return dev ? dev->type == &namespace_blk_device_type : false;
+}
+
+static bool is_namespace_io(const struct device *dev)
+{
+	return dev ? dev->type == &namespace_io_device_type : false;
+}
+
 struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
 {
 	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
@@ -2078,7 +2085,6 @@  static struct device *nd_namespace_blk_create(struct nd_region *nd_region)
 	}
 	dev_set_name(dev, "namespace%d.%d", nd_region->id, nsblk->id);
 	dev->parent = &nd_region->dev;
-	dev->groups = nd_namespace_attribute_groups;
 
 	return &nsblk->common.dev;
 }
@@ -2109,7 +2115,6 @@  static struct device *nd_namespace_pmem_create(struct nd_region *nd_region)
 		return NULL;
 	}
 	dev_set_name(dev, "namespace%d.%d", nd_region->id, nspm->id);
-	dev->groups = nd_namespace_attribute_groups;
 	nd_namespace_pmem_set_resource(nd_region, nspm, 0);
 
 	return dev;
@@ -2608,7 +2613,6 @@  int nd_region_register_namespaces(struct nd_region *nd_region, int *err)
 		if (id < 0)
 			break;
 		dev_set_name(dev, "namespace%d.%d", nd_region->id, id);
-		dev->groups = nd_namespace_attribute_groups;
 		nd_device_register(dev);
 	}
 	if (i)
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index ee5c04070ef9..5c8b077b3237 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -297,7 +297,7 @@  struct device *nd_pfn_create(struct nd_region *nd_region);
 struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
 		struct nd_namespace_common *ndns);
 int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig);
-extern struct attribute_group nd_pfn_attribute_group;
+extern const struct attribute_group *nd_pfn_attribute_groups[];
 #else
 static inline int nd_pfn_probe(struct device *dev,
 		struct nd_namespace_common *ndns)
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 60d81fae06ee..e809961e2b6f 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -26,17 +26,6 @@  static void nd_pfn_release(struct device *dev)
 	kfree(nd_pfn);
 }
 
-static struct device_type nd_pfn_device_type = {
-	.name = "nd_pfn",
-	.release = nd_pfn_release,
-};
-
-bool is_nd_pfn(struct device *dev)
-{
-	return dev ? dev->type == &nd_pfn_device_type : false;
-}
-EXPORT_SYMBOL(is_nd_pfn);
-
 struct nd_pfn *to_nd_pfn(struct device *dev)
 {
 	struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
@@ -287,18 +276,30 @@  static umode_t pfn_visible(struct kobject *kobj, struct attribute *a, int n)
 	return a->mode;
 }
 
-struct attribute_group nd_pfn_attribute_group = {
+static struct attribute_group nd_pfn_attribute_group = {
 	.attrs = nd_pfn_attributes,
 	.is_visible = pfn_visible,
 };
 
-static const struct attribute_group *nd_pfn_attribute_groups[] = {
+const struct attribute_group *nd_pfn_attribute_groups[] = {
 	&nd_pfn_attribute_group,
 	&nd_device_attribute_group,
 	&nd_numa_attribute_group,
 	NULL,
 };
 
+static const struct device_type nd_pfn_device_type = {
+	.name = "nd_pfn",
+	.release = nd_pfn_release,
+	.groups = nd_pfn_attribute_groups,
+};
+
+bool is_nd_pfn(struct device *dev)
+{
+	return dev ? dev->type == &nd_pfn_device_type : false;
+}
+EXPORT_SYMBOL(is_nd_pfn);
+
 struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
 		struct nd_namespace_common *ndns)
 {
@@ -337,7 +338,6 @@  static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
 
 	dev = &nd_pfn->dev;
 	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
-	dev->groups = nd_pfn_attribute_groups;
 	dev->type = &nd_pfn_device_type;
 	dev->parent = &nd_region->dev;