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

Dan Williams
2015-04-28T18:24:12Z

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