[PATCH v2 00/20] libnd: non-volatile memory device support

[Dan Williams <dan.j.williams@intel.com>]

Changes since v1 [1]: Incorporates feedback received prior to April 24.

1/ Ingo said [2]:

       "So why on earth is this whole concept and the naming itself
       ('drivers/block/nd/' stands for 'NFIT Defined', apparently)
       revolving around a specific 'firmware' mindset and revolving
       around specific, weirdly named, overly complicated looking
       firmware interfaces that come with their own new weird
       glossary??"

   Indeed, we of course consulted the NFIT specification to determine
   the shape of the sub-system, but then let its terms and data
   structures permeate too deep into the implementation.  That is fixed
   now with all NFIT specifics factored out into acpi.c.  The NFIT is no
   longer required reading to review libnd.  Only three concepts are
   needed:

      i/ PMEM - contiguous memory range where cpu stores are
	 persistent once they are flushed through the memory
         controller.

     ii/ BLK - mmio apertures (sliding windows) that can be
	 programmed to access an aperture's-worth of persistent
         media at a time.

    iii/ DPA - "dimm-physical-address", address space local to a
	 dimm.  A dimm may provide both PMEM-mode and BLK-mode
	 access to a range of DPA.  libnd manages allocation of DPA
         to either PMEM or BLK-namespaces to resolve this aliasing. 

   The v1..v2 diffstat below shows the migration of nfit-specifics to
   acpi.c and the new state of libnd being nfit-free.  "nd" now only
   refers to "non-volatile devices".  Note, reworked documentation will
   return once the review has settled.

   Documentation/blockdev/nd.txt     |  867 ---------------------
   MAINTAINERS                       |   34 +-
   arch/ia64/kernel/efi.c            |    5 +-
   arch/x86/kernel/e820.c            |   11 +-
   arch/x86/kernel/pmem.c            |    2 +-
   drivers/block/Makefile            |    2 +-
   drivers/block/nd/Kconfig          |  135 ++--
   drivers/block/nd/Makefile         |   32 +-
   drivers/block/nd/acpi.c           | 1506 +++++++++++++++++++++++++++++++------
   drivers/block/nd/acpi_nfit.h      |  321 ++++++++
   drivers/block/nd/blk.c            |   27 +-
   drivers/block/nd/btt.c            |    6 +-
   drivers/block/nd/btt_devs.c       |    8 +-
   drivers/block/nd/bus.c            |  337 +++++----
   drivers/block/nd/core.c           |  574 +-------------
   drivers/block/nd/dimm.c           |   11 -
   drivers/block/nd/dimm_devs.c      |  292 ++-----
   drivers/block/nd/e820.c           |  100 +++
   drivers/block/nd/libnd.h          |  122 +++
   drivers/block/nd/namespace_devs.c |   10 +-
   drivers/block/nd/nd-private.h     |  107 +--
   drivers/block/nd/nd.h             |   91 +--
   drivers/block/nd/nfit.h           |  238 ------
   drivers/block/nd/pmem.c           |   56 +-
   drivers/block/nd/region.c         |   78 +-
   drivers/block/nd/region_devs.c    |  783 +++----------------
   drivers/block/nd/test/iomap.c     |   86 +--
   drivers/block/nd/test/nfit.c      | 1115 +++++++++++++++------------
   drivers/block/nd/test/nfit_test.h |   15 +-
   include/uapi/linux/ndctl.h        |  130 ++--
   30 files changed, 3166 insertions(+), 3935 deletions(-)
   delete mode 100644 Documentation/blockdev/nd.txt
   create mode 100644 drivers/block/nd/acpi_nfit.h
   create mode 100644 drivers/block/nd/e820.c
   create mode 100644 drivers/block/nd/libnd.h
   delete mode 100644 drivers/block/nd/nfit.h

   [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-April/000484.html
   [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-April/000520.html

2/ Christoph asked the pmem ida conversion to be moved to its own patch
   (done), and to consider leaving the current pmem.c in drivers/block/.
   Instead, I converted the e820-type-12 enabling to be the first
   non-ACPI-NFIT based consumer of libnd.  The new nd_e820 driver simply
   registers e820-type-12 ranges as libnd PMEM regions.  Among other
   things this conversion enables BTT for these ranges.  The alternative
   is to move drivers/block/nd/nd.h internals out to include/linux/
   which I think is worse.

3/ Toshi reported that the NFIT parsing fails to handle the case of a
   PMEM range with a single-dimm (non-aliasing) interleave description.
   Support for this case was added and is tested by default by the
   nfit_test.1 configuration.

4/ Toshi reported that we should not be treating a missing _STA property
   as a "dimm disabled by firmware" case.  (fixed).

5/ Christoph noted that ND_ARCH_HAS_IOREMAP_CACHE needs to be moved to
   arch code.  It is gone for now and we'll revisit when adding cached
   mappings back to the PMEM driver.

6/ Toshi mentioned that the presence of two different nd_bus_probe()
   functions was confusing.  (cleaned up).

7/ Robert asked for s/btt_checksum/nd_btt_checksum/ (done).

8/ Linda asked for nfit_test to honor dynamic cma reservations via the
   cma= command line (done).  The cma requirements have also been
   reduced to 128M as only the simulated DAX regions need CMA.  The rest
   can use vmalloc().

---

Available here:
  git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm nd-v2

---

Dan Williams (18):
      e820, efi: add ACPI 6.0 persistent memory types
      libnd, nd_acpi: initial libnd infrastructure and NFIT support
      nd_acpi, nfit-test: manufactured NFITs for interface development
      libnd: ndctl class device, and nd bus attributes
      libnd, nd_acpi: dimm/memory-devices
      libnd: ndctl.h, the nd ioctl abi
      libnd, nd_dimm: dimm driver and base libnd device-driver infrastructure
      libnd, nd_acpi: regions (block-data-window, persistent memory, volatile memory)
      libnd: support for legacy (non-aliasing) nvdimms
      pmem: use ida
      libnd, nd_pmem: add libnd support to the pmem driver
      libnd, nd_acpi: add interleave-set state-tracking infrastructure
      libnd: namespace indices: read and validate
      libnd: pmem label sets and namespace instantiation.
      libnd: blk labels and namespace instantiation
      libnd: write pmem label set
      libnd: write blk label set
      libnd: infrastructure for btt devices

Ross Zwisler (1):
      libnd, nd_acpi, nd_blk: driver for BLK-mode access persistent memory

Vishal Verma (1):
      nd_btt: atomic sector updates


 Documentation/blockdev/btt.txt    |  273 ++++++
 arch/arm64/kernel/efi.c           |    1 
 arch/ia64/kernel/efi.c            |    4 
 arch/x86/boot/compressed/eboot.c  |    4 
 arch/x86/include/uapi/asm/e820.h  |    1 
 arch/x86/kernel/e820.c            |   26 +
 arch/x86/kernel/pmem.c            |    2 
 arch/x86/platform/efi/efi.c       |    3 
 drivers/block/Kconfig             |   13 
 drivers/block/Makefile            |    2 
 drivers/block/nd/Kconfig          |  129 +++
 drivers/block/nd/Makefile         |   41 +
 drivers/block/nd/acpi.c           | 1505 +++++++++++++++++++++++++++++++++
 drivers/block/nd/acpi_nfit.h      |  321 +++++++
 drivers/block/nd/blk.c            |  264 ++++++
 drivers/block/nd/btt.c            | 1423 +++++++++++++++++++++++++++++++
 drivers/block/nd/btt.h            |  185 ++++
 drivers/block/nd/btt_devs.c       |  443 ++++++++++
 drivers/block/nd/bus.c            |  770 +++++++++++++++++
 drivers/block/nd/core.c           |  471 ++++++++++
 drivers/block/nd/dimm.c           |  115 +++
 drivers/block/nd/dimm_devs.c      |  507 +++++++++++
 drivers/block/nd/e820.c           |  100 ++
 drivers/block/nd/label.c          |  925 ++++++++++++++++++++
 drivers/block/nd/label.h          |  143 +++
 drivers/block/nd/libnd.h          |  122 +++
 drivers/block/nd/namespace_devs.c | 1701 +++++++++++++++++++++++++++++++++++++
 drivers/block/nd/nd-private.h     |  114 ++
 drivers/block/nd/nd.h             |  261 ++++++
 drivers/block/nd/pmem.c           |  114 ++
 drivers/block/nd/region.c         |  159 +++
 drivers/block/nd/region_devs.c    |  637 ++++++++++++++
 drivers/block/nd/test/Makefile    |    5 
 drivers/block/nd/test/iomap.c     |  151 +++
 drivers/block/nd/test/nfit.c      | 1131 +++++++++++++++++++++++++
 drivers/block/nd/test/nfit_test.h |   26 +
 include/linux/efi.h               |    3 
 include/linux/nd.h                |   98 ++
 include/uapi/linux/Kbuild         |    1 
 include/uapi/linux/ndctl.h        |  199 ++++
 40 files changed, 12345 insertions(+), 48 deletions(-)
 create mode 100644 Documentation/blockdev/btt.txt
 create mode 100644 drivers/block/nd/Kconfig
 create mode 100644 drivers/block/nd/Makefile
 create mode 100644 drivers/block/nd/acpi.c
 create mode 100644 drivers/block/nd/acpi_nfit.h
 create mode 100644 drivers/block/nd/blk.c
 create mode 100644 drivers/block/nd/btt.c
 create mode 100644 drivers/block/nd/btt.h
 create mode 100644 drivers/block/nd/btt_devs.c
 create mode 100644 drivers/block/nd/bus.c
 create mode 100644 drivers/block/nd/core.c
 create mode 100644 drivers/block/nd/dimm.c
 create mode 100644 drivers/block/nd/dimm_devs.c
 create mode 100644 drivers/block/nd/e820.c
 create mode 100644 drivers/block/nd/label.c
 create mode 100644 drivers/block/nd/label.h
 create mode 100644 drivers/block/nd/libnd.h
 create mode 100644 drivers/block/nd/namespace_devs.c
 create mode 100644 drivers/block/nd/nd-private.h
 create mode 100644 drivers/block/nd/nd.h
 rename drivers/block/{pmem.c => nd/pmem.c} (68%)
 create mode 100644 drivers/block/nd/region.c
 create mode 100644 drivers/block/nd/region_devs.c
 create mode 100644 drivers/block/nd/test/Makefile
 create mode 100644 drivers/block/nd/test/iomap.c
 create mode 100644 drivers/block/nd/test/nfit.c
 create mode 100644 drivers/block/nd/test/nfit_test.h
 create mode 100644 include/linux/nd.h
 create mode 100644 include/uapi/linux/ndctl.h