[NDCTL PATCH v5 0/3] ndctl: Add support and test for CXL Features support

[Dave Jiang <dave.jiang@intel.com>]

v5:
- Add documentation for exported symbols. (Alison)
- Create 'struct cxl_fwctl' as object under cxl_memdev. (Dan)
- Make command prep common code. (Alison)
- Rename fwctl.c to cxl-features-control.c. (Alison)
- See individual commits for specific changes from v4.

v4:
- Adjust to kernel changes of input/output structs
- Fixup skip/pass/fail logic
- Added new kernel headers detection and dependency in meson.build

v3:
- Update test to use opcode instead of command id.

v2:
- Drop features device enumeration
- Add discovery of char device under memdev

The series provides support of libcxl enumerating FWCTL character device
under the cxl_memdev device. It discovers the char device major
and minor numbers for the CXL features device in order to allow issuing
of ioctls to the device. 

A unit test is added to locate cxl_memdev exported by the cxl_test
kernel module and issue all the supported ioctls to the associated
FWCTL char device to verify that all the ioctl paths are working as expected.

Kernel series: https://lore.kernel.org/linux-cxl/20250207233914.2375110-1-dave.jiang@intel.com/T/#t

Dave Jiang (3):
      cxl: Add cxl_bus_get_by_provider()
      cxl: Enumerate major/minor of FWCTL char device
      cxl/test: Add test for cxl features device

 Documentation/cxl/lib/libcxl.txt |  23 ++++
 cxl/lib/libcxl.c                 |  89 ++++++++++++
 cxl/lib/libcxl.sym               |   8 ++
 cxl/lib/private.h                |   8 ++
 cxl/libcxl.h                     |   7 +
 test/cxl-features-control.c      | 439 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 test/cxl-features.sh             |  31 +++++
 test/cxl-topology.sh             |   4 +
 test/meson.build                 |  45 ++++++
 9 files changed, 654 insertions(+)