[PATCH v4 0/3] selftests/resctrl: Fix resctrl selftests issues on aarch64

[Richard Cheng <icheng@nvidia.com>]

This series fixes numerous issues in the resctrl selftests on aarch64,
where they currently misreport failures.

Patch 1 skips L3_CAT at feature-check time when MPAM legitimately
reports every CBM bit as shareable, instead of failing the test.

Patch 2 adds aarch64 implementations of cl_flush() and sb() in
fill_buf.c so cache flushes are no longer silent no-ops.

Patch 3 teaches detect_vendor() about aarch64 (which exposes no
vendor_id in /proc/cpuinfo) and lets arch_supports_noncont_cat()
return true for ARM, fixing spurious L3_NONCONT_CAT failures.

Changes since v3:
    - Patch 2: replace "dc civac" in cl_flush() with a dirty store, per
      Ben Horgan's feedback that dc civac only cleans to the Point of
      Coherency and does not reach the SLC where MPAM cache portions
      are enforced.
    - Patch 1, Patch 3: no code changes.

Richard Cheng (3):
  selftests/resctrl: Skip L3_CAT when no exclusive cache portion exists
  selftests/resctrl: Implement cl_flush() and sb() for aarch64
  selftests/resctrl: Recognise aarch64 as a vendor for L3_NONCONT_CAT

 tools/testing/selftests/resctrl/cat_test.c    | 32 +++++++++++++++++--
 tools/testing/selftests/resctrl/fill_buf.c    | 11 +++++++
 tools/testing/selftests/resctrl/resctrl.h     |  1 +
 .../testing/selftests/resctrl/resctrl_tests.c | 21 ++++++++++++
 4 files changed, 62 insertions(+), 3 deletions(-)

-- 
2.43.0