diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
index 6eb6dfdf19bf..2bedf8414fff 100644
--- a/drivers/dax/pmem/core.c
+++ b/drivers/dax/pmem/core.c
@@ -25,20 +25,20 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 	ndns = nvdimm_namespace_common_probe(dev);
 	if (IS_ERR(ndns))
 		return ERR_CAST(ndns);
-	nsio = to_nd_namespace_io(&ndns->dev);
 
 	/* parse the 'pfn' info block via ->rw_bytes */
-	rc = devm_nsio_enable(dev, nsio);
+	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
 	if (rc)
 		return ERR_PTR(rc);
 	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
 	if (rc)
 		return ERR_PTR(rc);
-	devm_nsio_disable(dev, nsio);
+	devm_namespace_disable(dev, ndns);
 
 	/* reserve the metadata area, device-dax will reserve the data */
 	pfn_sb = nd_pfn->pfn_sb;
 	offset = le64_to_cpu(pfn_sb->dataoff);
+	nsio = to_nd_namespace_io(&ndns->dev);
 	if (!devm_request_mem_region(dev, nsio->res.start, offset,
 				dev_name(&ndns->dev))) {
 		dev_warn(dev, "could not reserve metadata\n");
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 3e9f45aec8d1..8cb890a987b0 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1674,7 +1674,8 @@ int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
 	struct nd_region *nd_region;
 	struct btt_sb *btt_sb;
 	struct btt *btt;
-	size_t rawsize;
+	size_t size, rawsize;
+	int rc;
 
 	if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize) {
 		dev_dbg(&nd_btt->dev, "incomplete btt configuration\n");
@@ -1685,6 +1686,11 @@ int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
 	if (!btt_sb)
 		return -ENOMEM;
 
+	size = nvdimm_namespace_capacity(ndns);
+	rc = devm_namespace_enable(&nd_btt->dev, ndns, size);
+	if (rc)
+		return rc;
+
 	/*
 	 * If this returns < 0, that is ok as it just means there wasn't
 	 * an existing BTT, and we're creating a new one. We still need to
@@ -1693,7 +1699,7 @@ int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
 	 */
 	nd_btt_version(nd_btt, ndns, btt_sb);
 
-	rawsize = nvdimm_namespace_capacity(ndns) - nd_btt->initial_offset;
+	rawsize = size - nd_btt->initial_offset;
 	if (rawsize < ARENA_MIN_SIZE) {
 		dev_dbg(&nd_btt->dev, "%s must be at least %ld bytes\n",
 				dev_name(&ndns->dev),
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 2985ca949912..45964acba944 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -300,13 +300,14 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
 	return rc;
 }
 
-int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio)
+int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
+		resource_size_t size)
 {
 	struct resource *res = &nsio->res;
 	struct nd_namespace_common *ndns = &nsio->common;
 
-	nsio->size = resource_size(res);
-	if (!devm_request_mem_region(dev, res->start, resource_size(res),
+	nsio->size = size;
+	if (!devm_request_mem_region(dev, res->start, size,
 				dev_name(&ndns->dev))) {
 		dev_warn(dev, "could not reserve region %pR\n", res);
 		return -EBUSY;
@@ -318,12 +319,10 @@ int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio)
 	nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
 			&nsio->res);
 
-	nsio->addr = devm_memremap(dev, res->start, resource_size(res),
-			ARCH_MEMREMAP_PMEM);
+	nsio->addr = devm_memremap(dev, res->start, size, ARCH_MEMREMAP_PMEM);
 
 	return PTR_ERR_OR_ZERO(nsio->addr);
 }
-EXPORT_SYMBOL_GPL(devm_nsio_enable);
 
 void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
 {
@@ -331,6 +330,5 @@ void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
 
 	devm_memunmap(dev, nsio->addr);
 	devm_exit_badblocks(dev, &nsio->bb);
-	devm_release_mem_region(dev, res->start, resource_size(res));
+	devm_release_mem_region(dev, res->start, nsio->size);
 }
-EXPORT_SYMBOL_GPL(devm_nsio_disable);
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 829f7bdaaa6d..c90664387ee5 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1759,6 +1759,23 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
 }
 EXPORT_SYMBOL(nvdimm_namespace_common_probe);
 
+int devm_namespace_enable(struct device *dev, struct nd_namespace_common *ndns,
+		resource_size_t size)
+{
+	if (is_namespace_blk(&ndns->dev))
+		return 0;
+	return devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev), size);
+}
+EXPORT_SYMBOL_GPL(devm_namespace_enable);
+
+void devm_namespace_disable(struct device *dev, struct nd_namespace_common *ndns)
+{
+	if (is_namespace_blk(&ndns->dev))
+		return;
+	devm_nsio_disable(dev, to_nd_namespace_io(&ndns->dev));
+}
+EXPORT_SYMBOL_GPL(devm_namespace_disable);
+
 static struct device **create_namespace_io(struct nd_region *nd_region)
 {
 	struct nd_namespace_io *nsio;
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 25fa121104d0..96e8630f451c 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -171,6 +171,23 @@ ssize_t nd_namespace_store(struct device *dev,
 struct nd_pfn *to_nd_pfn_safe(struct device *dev);
 bool is_nvdimm_bus(struct device *dev);
 
+#if IS_ENABLED(CONFIG_ND_CLAIM)
+int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
+		resource_size_t size);
+void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio);
+#else
+static inline int devm_nsio_enable(struct device *dev,
+		struct nd_namespace_io *nsio, resource_size_t size)
+{
+	return -ENXIO;
+}
+
+static inline void devm_nsio_disable(struct device *dev,
+		struct nd_namespace_io *nsio)
+{
+}
+#endif
+
 #ifdef CONFIG_PROVE_LOCKING
 extern struct class *nd_class;
 
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index ee5c04070ef9..a9f338d01a55 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -212,6 +212,11 @@ struct nd_dax {
 	struct nd_pfn nd_pfn;
 };
 
+static inline u32 nd_info_block_reserve(void)
+{
+	return ALIGN(SZ_8K, PAGE_SIZE);
+}
+
 enum nd_async_mode {
 	ND_SYNC,
 	ND_ASYNC,
@@ -370,29 +375,20 @@ const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
 unsigned int pmem_sector_size(struct nd_namespace_common *ndns);
 void nvdimm_badblocks_populate(struct nd_region *nd_region,
 		struct badblocks *bb, const struct resource *res);
+int devm_namespace_enable(struct device *dev, struct nd_namespace_common *ndns,
+		resource_size_t size);
+void devm_namespace_disable(struct device *dev,
+		struct nd_namespace_common *ndns);
 #if IS_ENABLED(CONFIG_ND_CLAIM)
-
 /* max struct page size independent of kernel config */
 #define MAX_STRUCT_PAGE_SIZE 64
-
 int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap);
-int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio);
-void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio);
 #else
 static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
 				   struct dev_pagemap *pgmap)
 {
 	return -ENXIO;
 }
-static inline int devm_nsio_enable(struct device *dev,
-		struct nd_namespace_io *nsio)
-{
-	return -ENXIO;
-}
-static inline void devm_nsio_disable(struct device *dev,
-		struct nd_namespace_io *nsio)
-{
-}
 #endif
 int nd_blk_region_init(struct nd_region *nd_region);
 int nd_region_activate(struct nd_region *nd_region);
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 96727fd493f7..3ca6c97cd14d 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -382,6 +382,15 @@ static int nd_pfn_clear_memmap_errors(struct nd_pfn *nd_pfn)
 	meta_start = (SZ_4K + sizeof(*pfn_sb)) >> 9;
 	meta_num = (le64_to_cpu(pfn_sb->dataoff) >> 9) - meta_start;
 
+	/*
+	 * re-enable the namespace with correct size so that we can access
+	 * the device memmap area.
+	 */
+	devm_namespace_disable(&nd_pfn->dev, ndns);
+	rc = devm_namespace_enable(&nd_pfn->dev, ndns, le64_to_cpu(pfn_sb->dataoff));
+	if (rc)
+		return rc;
+
 	do {
 		unsigned long zero_len;
 		u64 nsoff;
@@ -635,11 +644,6 @@ int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 }
 EXPORT_SYMBOL(nd_pfn_probe);
 
-static u32 info_block_reserve(void)
-{
-	return ALIGN(SZ_8K, PAGE_SIZE);
-}
-
 /*
  * We hotplug memory at sub-section granularity, pad the reserved area
  * from the previous section base to the namespace base address.
@@ -653,7 +657,7 @@ static unsigned long init_altmap_base(resource_size_t base)
 
 static unsigned long init_altmap_reserve(resource_size_t base)
 {
-	unsigned long reserve = info_block_reserve() >> PAGE_SHIFT;
+	unsigned long reserve = nd_info_block_reserve() >> PAGE_SHIFT;
 	unsigned long base_pfn = PHYS_PFN(base);
 
 	reserve += base_pfn - SUBSECTION_ALIGN_DOWN(base_pfn);
@@ -668,7 +672,7 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 	u64 offset = le64_to_cpu(pfn_sb->dataoff);
 	u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 	u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
-	u32 reserve = info_block_reserve();
+	u32 reserve = nd_info_block_reserve();
 	struct nd_namespace_common *ndns = nd_pfn->ndns;
 	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 	resource_size_t base = nsio->res.start + start_pad;
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index f9f76f6ba07b..7a6f4501dcda 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -372,6 +372,10 @@ static int pmem_attach_disk(struct device *dev,
 	if (!pmem)
 		return -ENOMEM;
 
+	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
+	if (rc)
+		return rc;
+
 	/* while nsio_rw_bytes is active, parse a pfn info block if present */
 	if (is_nd_pfn(dev)) {
 		nd_pfn = to_nd_pfn(dev);
@@ -381,7 +385,7 @@ static int pmem_attach_disk(struct device *dev,
 	}
 
 	/* we're attaching a block device, disable raw namespace access */
-	devm_nsio_disable(dev, nsio);
+	devm_namespace_disable(dev, ndns);
 
 	dev_set_drvdata(dev, pmem);
 	pmem->phys_addr = res->start;
@@ -497,15 +501,16 @@ static int nd_pmem_probe(struct device *dev)
 	if (IS_ERR(ndns))
 		return PTR_ERR(ndns);
 
-	if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
-		return -ENXIO;
-
 	if (is_nd_btt(dev))
 		return nvdimm_namespace_attach_btt(ndns);
 
 	if (is_nd_pfn(dev))
 		return pmem_attach_disk(dev, ndns);
 
+	ret = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
+	if (ret)
+		return ret;
+
 	ret = nd_btt_probe(dev, ndns);
 	if (ret == 0)
 		return -ENXIO;
@@ -532,6 +537,10 @@ static int nd_pmem_probe(struct device *dev)
 		return -ENXIO;
 	else if (ret == -EOPNOTSUPP)
 		return ret;
+
+	/* probe complete, attach handles namespace enabling */
+	devm_namespace_disable(dev, ndns);
+
 	return pmem_attach_disk(dev, ndns);
 }