libnvdimm: Non-Volatile Devices

Maintainer information and documentation for drivers/nvdimm

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>
Cc: Neil Brown <neilb@suse.de>
Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Documentation/nvdimm/btt.txt

@@ -80,9 +80,17 @@ block. Each map entry is 32 bits. The two most significant bits are special
 flags, and the remaining form the internal block number.
 
 Bit      Description
-31     : TRIM flag - marks if the block was trimmed or discarded
-30     : ERROR flag - marks an error block. Cleared on write.
-29 - 0 : Mappings to internal 'postmap' blocks
+31 - 30	: Error and Zero flags - Used in the following way:
+	 Bit		      Description
+	31 30
+	-----------------------------------------------------------------------
+	 00	Initial state. Reads return zeroes; Premap = Postmap
+	 01	Zero state: Reads return zeroes
+	 10	Error state: Reads fail; Writes clear 'E' bit
+	 11	Normal Block – has valid postmap
+
+
+29 - 0	: Mappings to internal 'postmap' blocks
 
 
 Some of the terminology that will be subsequently used:
@@ -127,10 +135,11 @@ old_map': alternate old postmap entry
 new_map': alternate new postmap entry
 seq'	: alternate sequence number.
 
-Each of the above fields is 32-bit, making one entry 16 bytes. Flog updates are
+Each of the above fields is 32-bit, making one entry 32 bytes. Entries are also
+padded to 64 bytes to avoid cache line sharing or aliasing. Flog updates are
 done such that for any entry being written, it:
 a. overwrites the 'old' section in the entry based on sequence numbers
-b. writes the new entry such that the sequence number is written last.
+b. writes the 'new' section such that the sequence number is written last.
 
 
 c. The concept of lanes
@@ -141,8 +150,9 @@ concurrently, 'nlanes' is the number of IOs the BTT device as a whole can
 process.
  nlanes = min(nfree, num_cpus)
 A lane number is obtained at the start of any IO, and is used for indexing into
-all the on-disk and in-memory data structures for the duration of the IO. It is
-protected by a spinlock.
+all the on-disk and in-memory data structures for the duration of the IO. If
+there are more CPUs than the max number of available lanes, than lanes are
+protected by spinlocks.
 
 
 d. In-memory data structure: Read Tracking Table (RTT)

MAINTAINERS

@@ -5912,6 +5912,39 @@ M:	Sasha Levin <sasha.levin@oracle.com>
 S:	Maintained
 F:	tools/lib/lockdep/
 
+LIBNVDIMM: NON-VOLATILE MEMORY DEVICE SUBSYSTEM
+M:	Dan Williams <dan.j.williams@intel.com>
+L:	linux-nvdimm@lists.01.org
+Q:	https://patchwork.kernel.org/project/linux-nvdimm/list/
+S:	Supported
+F:	drivers/nvdimm/*
+F:	include/linux/nd.h
+F:	include/linux/libnvdimm.h
+F:	include/uapi/linux/ndctl.h
+
+LIBNVDIMM BLK: MMIO-APERTURE DRIVER
+M:	Ross Zwisler <ross.zwisler@linux.intel.com>
+L:	linux-nvdimm@lists.01.org
+Q:	https://patchwork.kernel.org/project/linux-nvdimm/list/
+S:	Supported
+F:	drivers/nvdimm/blk.c
+F:	drivers/nvdimm/region_devs.c
+F:	drivers/acpi/nfit*
+
+LIBNVDIMM BTT: BLOCK TRANSLATION TABLE
+M:	Vishal Verma <vishal.l.verma@intel.com>
+L:	linux-nvdimm@lists.01.org
+Q:	https://patchwork.kernel.org/project/linux-nvdimm/list/
+S:	Supported
+F:	drivers/nvdimm/btt*
+
+LIBNVDIMM PMEM: PERSISTENT MEMORY DRIVER
+M:	Ross Zwisler <ross.zwisler@linux.intel.com>
+L:	linux-nvdimm@lists.01.org
+Q:	https://patchwork.kernel.org/project/linux-nvdimm/list/
+S:	Supported
+F:	drivers/nvdimm/pmem.c
+
 LINUX FOR IBM pSERIES (RS/6000)
 M:	Paul Mackerras <paulus@au.ibm.com>
 W:	http://www.ibm.com/linux/ltc/projects/ppc
@@ -8136,12 +8169,6 @@ S:	Maintained
 F:	Documentation/blockdev/ramdisk.txt
 F:	drivers/block/brd.c
 
-PERSISTENT MEMORY DRIVER
-M:	Ross Zwisler <ross.zwisler@linux.intel.com>
-L:	linux-nvdimm@lists.01.org
-S:	Supported
-F:	drivers/block/pmem.c
-
 RANDOM NUMBER DRIVER
 M:	"Theodore Ts'o" <tytso@mit.edu>
 S:	Maintained