[ndctl,v2,00/10] cxl: add region management

Message

Verma, Vishal L Aug. 10, 2022, 11:09 p.m. UTC

Changes since v1[1]:
- Collect review tags
- Fix order of setting region size vs UUID (Dan)
- Rename region_{commit,decommit} to region_decode{commit,reset} everywhere (Dan)
- Add a -b <bus> option to all region management commands
- Add a cxl-create-region unit test
- Use walk_children pattern for root decoders vs. regions (Dan)
- Add bus, port, and (root) decoder based filters for regions (Dan)
- Add a 'REGIONS' section to the libcxl(3) documentation (Dan)
- s/--interleave-ways/--ways/ and
  s/interleave-granularity/--granularity/ (Dan)
- Rename and clarify memdev_match_set_size() with a comment (Dan)
- Remove a double init in memdev_match_set_size() (Dan)
- Rework granularity determination (Dan)
- Ensure ep_decoder is free before changing its mode (Dan)
- Fix a mid-series compile breakage in region_action() (Dan)
- Fix missing whitespace in region_action() (Dan)
- Refactor region_action for too much indentation (Dan)
- Save error state from multi-region operations in region_action()
- Free leaky region objects (when the parent decoder is freed)
- Consider root decoder's available size before creating a region (Dan)


[1]: https://lore.kernel.org/linux-cxl/[e-mail]/

---

Introduce the first cut at a 'cxl create-region' command, which uses the
ABI merged in the kernel in [2], and builds on the create-region foundation
laid out in [3].

This introduces libcxl objects for regions and their memdev mappings,
adds listing support for them, and libcxl APIs to create, enable,
disable, and destroy regions. These are consumed by respective cxl-cli
commands to perform the same region management operations.

The 'cxl create-region' command deserves a bit more detail. Its current
version can be considered a fundamental 'plumbing' implementation. It
allows, and in some cases, requires the user to specify the parameters
for the region being created. Future enhancements to this will allow a
simple 'cxl create-region' invocation to automatically pick suitable
root decoders, memdev endpoints, and interleave settings to create a
maximally sized and interleaved region.

Today, the create-region command requires the following from the user:

  -d <root decoder> : the root decoder (CFMWS window) under which to
  create the region

  -m or -e <targets>: the memdev or endpoint decoder targets that will
  form the new region

It can pick the following settings automatically (though the user can
also override these if desired):

  -w : interleave ways - picked based on the number of memdev / endpoint
  decoder targets supplied

  -g : interleave granularity - selects the interleave granularity
  advertised by the root decoder

  -t : type of region - defaults to pmem. The ram (volatile) type is not
  supported yet.

  -s : size of region - deduced based on sizes of the specified targets

[2]: https://git.kernel.org/torvalds/c/c235698355fa94df7073b51befda7d4be00a0e23
[3]: https://lore.kernel.org/linux-cxl/[e-mail]/


Vishal Verma (10):
  libcxl: add a depth attribute to cxl_port
  cxl/port: Consolidate the debug option in cxl-port man pages
  libcxl: Introduce libcxl region and mapping objects
  cxl-cli: add region listing support
  libcxl: add low level APIs for region creation
  cxl: add a 'create-region' command
  cxl: add commands to {enable,disable,destroy}-region
  cxl/list: make memdevs and regions the default listing
  test: add a cxl-create-region test
  cxl/decoder: add a max_available_extent attribute

 Documentation/cxl/bus-option.txt         |   5 +
 Documentation/cxl/cxl-create-region.txt  | 114 +++
 Documentation/cxl/cxl-destroy-region.txt |  41 ++
 Documentation/cxl/cxl-disable-port.txt   |   5 +-
 Documentation/cxl/cxl-disable-region.txt |  36 +
 Documentation/cxl/cxl-enable-port.txt    |   5 +-
 Documentation/cxl/cxl-enable-region.txt  |  36 +
 Documentation/cxl/cxl-list.txt           |  13 +-
 Documentation/cxl/debug-option.txt       |   4 +
 Documentation/cxl/decoder-option.txt     |   6 +
 Documentation/cxl/lib/libcxl.txt         |  69 ++
 Documentation/cxl/region-description.txt |   7 +
 cxl/lib/private.h                        |  38 +
 cxl/lib/libcxl.c                         | 889 ++++++++++++++++++++++-
 cxl/builtin.h                            |   4 +
 cxl/filter.h                             |   6 +
 cxl/json.h                               |   5 +
 cxl/libcxl.h                             |  67 +-
 cxl/cxl.c                                |   4 +
 cxl/filter.c                             | 158 +++-
 cxl/json.c                               | 131 ++++
 cxl/list.c                               |  26 +-
 cxl/region.c                             | 797 ++++++++++++++++++++
 .clang-format                            |   2 +
 Documentation/cxl/meson.build            |   7 +
 cxl/lib/libcxl.sym                       |  37 +
 cxl/meson.build                          |   1 +
 test/cxl-create-region.sh                | 126 ++++
 test/meson.build                         |   2 +
 29 files changed, 2598 insertions(+), 43 deletions(-)
 create mode 100644 Documentation/cxl/bus-option.txt
 create mode 100644 Documentation/cxl/cxl-create-region.txt
 create mode 100644 Documentation/cxl/cxl-destroy-region.txt
 create mode 100644 Documentation/cxl/cxl-disable-region.txt
 create mode 100644 Documentation/cxl/cxl-enable-region.txt
 create mode 100644 Documentation/cxl/debug-option.txt
 create mode 100644 Documentation/cxl/decoder-option.txt
 create mode 100644 Documentation/cxl/region-description.txt
 create mode 100644 cxl/region.c
 create mode 100644 test/cxl-create-region.sh