libnvdimm/namespace: Differentiate between probe mapping and runtime mapping

The nvdimm core currently maps the full namespace to an ioremap range
while probing the namespace mode. This can result in probe failures on
architectures that have limited ioremap space.

For example, with a large btt namespace that consumes most of I/O remap
range, depending on the sequence of namespace initialization, the user
can find a pfn namespace initialization failure due to unavailable I/O
remap space which nvdimm core uses for temporary mapping.

nvdimm core can avoid this failure by only mapping the reserved info
block area to check for pfn superblock type and map the full namespace
resource only before using the namespace.

Given that personalities like BTT can be layered on top of any namespace
type create a generic form of devm_nsio_enable (devm_namespace_enable)
and use it inside the per-personality attach routines. Now
devm_namespace_enable() is always paired with disable unless the mapping
is going to be used for long term runtime access.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20191017073308.32645-1-aneesh.kumar@linux.ibm.com
[djbw: reworks to move devm_namespace_{en,dis}able into *attach helpers]
Reported-by: kbuild test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20191031105741.102793-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 9 insertions, 13 deletions

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);