libnvdimm: add an api to cast a 'struct nd_region' to its 'struct device'

djbw · djbw · commit 243f29fe449b · 2018-04-03T11:51:42.000-07:00
For debug, it is useful for bus providers to be able to retrieve the
'struct device' associated with an nd_region instance that it
registered. We already have to_nd_region() to perform the reverse cast
operation, in fact its duplicate declaration can be removed from the
private drivers/nvdimm/nd.h header.

Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
@@ -341,7 +341,6 @@ static inline struct device *nd_dax_create(struct nd_region *nd_region)
 }
 #endif
 
-struct nd_region *to_nd_region(struct device *dev);
 int nd_region_to_nstype(struct nd_region *nd_region);
 int nd_region_register_namespaces(struct nd_region *nd_region, int *err);
 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
@@ -182,6 +182,14 @@ struct nd_region *to_nd_region(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(to_nd_region);
 
+struct device *nd_region_dev(struct nd_region *nd_region)
+{
+	if (!nd_region)
+		return NULL;
+	return &nd_region->dev;
+}
+EXPORT_SYMBOL_GPL(nd_region_dev);
+
 struct nd_blk_region *to_nd_blk_region(struct device *dev)
 {
 	struct nd_region *nd_region = to_nd_region(dev);
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
@@ -164,6 +164,7 @@ void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus);
 struct nvdimm_bus *to_nvdimm_bus(struct device *dev);
 struct nvdimm *to_nvdimm(struct device *dev);
 struct nd_region *to_nd_region(struct device *dev);
+struct device *nd_region_dev(struct nd_region *nd_region);
 struct nd_blk_region *to_nd_blk_region(struct device *dev);
 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus);
 struct device *to_nvdimm_bus_dev(struct nvdimm_bus *nvdimm_bus);

Original file line number	Diff line number	Diff line change
`@@ -341,7 +341,6 @@ static inline struct device nd_dax_create(struct nd_region nd_region)`
`341`	`341`	`}`
`342`	`342`	`#endif`
`343`	`343`
`344`		`-struct nd_region to_nd_region(struct device dev);`
`345`	`344`	`int nd_region_to_nstype(struct nd_region *nd_region);`
`346`	`345`	`int nd_region_register_namespaces(struct nd_region nd_region, int err);`
`347`	`346`	`u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,`
Original file line number	Diff line number	Diff line change
`@@ -182,6 +182,14 @@ struct nd_region to_nd_region(struct device dev)`
`182`	`182`	`}`
`183`	`183`	`EXPORT_SYMBOL_GPL(to_nd_region);`
`184`	`184`
	`185`	`+struct device nd_region_dev(struct nd_region nd_region)`
	`186`	`+{`
	`187`	`+ if (!nd_region)`
	`188`	`+ return NULL;`
	`189`	`+ return &nd_region->dev;`
	`190`	`+}`
	`191`	`+EXPORT_SYMBOL_GPL(nd_region_dev);`
	`192`	`+`
`185`	`193`	`struct nd_blk_region to_nd_blk_region(struct device dev)`
`186`	`194`	`{`
`187`	`195`	`struct nd_region *nd_region = to_nd_region(dev);`