libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory

The libnvdimm implementation handles allocating dimm address space (DPA)
between PMEM and BLK mode interfaces.  After DPA has been allocated from
a BLK-region to a BLK-namespace the nd_blk driver attaches to handle I/O
as a struct bio based block device. Unlike PMEM, BLK is required to
handle platform specific details like mmio register formats and memory
controller interleave.  For this reason the libnvdimm generic nd_blk
driver calls back into the bus provider to carry out the I/O.

This initial implementation handles the BLK interface defined by the
ACPI 6 NFIT [1] and the NVDIMM DSM Interface Example [2] composed from
DCR (dimm control region), BDW (block data window), IDT (interleave
descriptor) NFIT structures and the hardware register format.
[1]: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf
[2]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 25 insertions, 2 deletions

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 531d99dfac68..7fc1b25bdb5d 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -14,6 +14,7 @@
  */
 #ifndef __LIBNVDIMM_H__
 #define __LIBNVDIMM_H__
+#include <linux/kernel.h>
 #include <linux/sizes.h>
 #include <linux/types.h>
 
@@ -89,8 +90,24 @@ struct nd_region_desc {
 };
 
 struct nvdimm_bus;
-struct device;
 struct module;
+struct device;
+struct nd_blk_region;
+struct nd_blk_region_desc {
+        int (*enable)(struct nvdimm_bus *nvdimm_bus, struct device *dev);
+        void (*disable)(struct nvdimm_bus *nvdimm_bus, struct device *dev);
+        int (*do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,
+                        void *iobuf, u64 len, int rw);
+        struct nd_region_desc ndr_desc;
+};
+
+static inline struct nd_blk_region_desc *to_blk_region_desc(
+                struct nd_region_desc *ndr_desc)
+{
+        return container_of(ndr_desc, struct nd_blk_region_desc, ndr_desc);
+
+}
+
 struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
                 struct nvdimm_bus_descriptor *nfit_desc, struct module *module);
 #define nvdimm_bus_register(parent, desc) \
@@ -99,10 +116,10 @@ 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 nd_blk_region *to_nd_blk_region(struct device *dev);
 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus);
 const char *nvdimm_name(struct nvdimm *nvdimm);
 void *nvdimm_provider_data(struct nvdimm *nvdimm);
-void *nd_region_provider_data(struct nd_region *nd_region);
 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
                 const struct attribute_group **groups, unsigned long flags,
                 unsigned long *dsm_mask);
@@ -120,5 +137,11 @@ struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
                 struct nd_region_desc *ndr_desc);
 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
                 struct nd_region_desc *ndr_desc);
+void *nd_region_provider_data(struct nd_region *nd_region);
+void *nd_blk_region_provider_data(struct nd_blk_region *ndbr);
+void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data);
+struct nvdimm *nd_blk_region_to_dimm(struct nd_blk_region *ndbr);
+unsigned int nd_region_acquire_lane(struct nd_region *nd_region);
+void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane);
 u64 nd_fletcher64(void *addr, size_t len, bool le);
 #endif /* __LIBNVDIMM_H__ */