libnvdimm: Fix endian conversion issues

nd_label->dpa issue was observed when trying to enable the namespace created
with little-endian kernel on a big-endian kernel. That made me run
`sparse` on the rest of the code and other changes are the result of that.

Fixes: d9b83c75 ("libnvdimm, btt: rework error clearing")
Fixes: 9dedc73a ("libnvdimm/btt: Fix LBA masking during 'free list' population")
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190809074726.27815-1-aneesh.kumar@linux.ibm.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/btt.c

@@ -392,9 +392,9 @@ static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub,
 	arena->freelist[lane].sub = 1 - arena->freelist[lane].sub;
 	if (++(arena->freelist[lane].seq) == 4)
 		arena->freelist[lane].seq = 1;
-	if (ent_e_flag(ent->old_map))
+	if (ent_e_flag(le32_to_cpu(ent->old_map)))
 		arena->freelist[lane].has_err = 1;
-	arena->freelist[lane].block = le32_to_cpu(ent_lba(ent->old_map));
+	arena->freelist[lane].block = ent_lba(le32_to_cpu(ent->old_map));
 
 	return ret;
 }
@@ -560,8 +560,8 @@ static int btt_freelist_init(struct arena_info *arena)
 		 * FIXME: if error clearing fails during init, we want to make
 		 * the BTT read-only
 		 */
-		if (ent_e_flag(log_new.old_map) &&
-				!ent_normal(log_new.old_map)) {
+		if (ent_e_flag(le32_to_cpu(log_new.old_map)) &&
+		    !ent_normal(le32_to_cpu(log_new.old_map))) {
 			arena->freelist[i].has_err = 1;
 			ret = arena_clear_freelist_error(arena, i);
 			if (ret)

drivers/nvdimm/namespace_devs.c

@@ -1987,7 +1987,7 @@ static struct device *create_namespace_pmem(struct nd_region *nd_region,
 		nd_mapping = &nd_region->mapping[i];
 		label_ent = list_first_entry_or_null(&nd_mapping->labels,
 				typeof(*label_ent), list);
-		label0 = label_ent ? label_ent->label : 0;
+		label0 = label_ent ? label_ent->label : NULL;
 
 		if (!label0) {
 			WARN_ON(1);
@@ -2322,8 +2322,9 @@ static struct device **scan_labels(struct nd_region *nd_region)
 			continue;
 
 		/* skip labels that describe extents outside of the region */
-		if (nd_label->dpa < nd_mapping->start || nd_label->dpa > map_end)
-			continue;
+		if (__le64_to_cpu(nd_label->dpa) < nd_mapping->start ||
+		    __le64_to_cpu(nd_label->dpa) > map_end)
+				continue;
 
 		i = add_namespace_resource(nd_region, nd_label, devs, count);
 		if (i < 0)