libnvdimm, pmem, pfn: make pmem_rw_bytes generic and refactor pfn setup

In preparation for providing an alternative (to block device) access
mechanism to persistent memory, convert pmem_rw_bytes() to
nsio_rw_bytes().  This allows ->rw_bytes() functionality without
requiring a 'struct pmem_device' to be instantiated.

In other words, when ->rw_bytes() is in use i/o is driven through
'struct nd_namespace_io', otherwise it is driven through 'struct
pmem_device' and the block layer.  This consolidates the disjoint calls
to devm_exit_badblocks() and devm_memunmap() into a common
devm_nsio_disable() and cleans up the init path to use a unified
pmem_attach_disk() implementation.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/nd.h b/include/linux/nd.h
index 5ea4aec..aee2761 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -15,6 +15,7 @@
 #include <linux/fs.h>
 #include <linux/ndctl.h>
 #include <linux/device.h>
+#include <linux/badblocks.h>
 
 enum nvdimm_event {
 	NVDIMM_REVALIDATE_POISON,
@@ -55,13 +56,19 @@ static inline struct nd_namespace_common *to_ndns(struct device *dev)
 }
 
 /**
- * struct nd_namespace_io - infrastructure for loading an nd_pmem instance
+ * struct nd_namespace_io - device representation of a persistent memory range
  * @dev: namespace device created by the nd region driver
  * @res: struct resource conversion of a NFIT SPA table
+ * @size: cached resource_size(@res) for fast path size checks
+ * @addr: virtual address to access the namespace range
+ * @bb: badblocks list for the namespace range
  */
 struct nd_namespace_io {
 	struct nd_namespace_common common;
 	struct resource res;
+	resource_size_t size;
+	void __pmem *addr;
+	struct badblocks bb;
 };
 
 /**