[PATCH v5 0/4] kselftest/arm64: Vector length configuration tests

[Mark Brown]

Currently we don't have full automated tests for the vector length
configuation ABIs offered for SVE, we have a helper binary for setting
the vector length which can be used for manual tests and we use the
prctl() interface to enumerate the vector lengths but don't actually
verify that the vector lengths enumerated were set.

This patch series provides a small helper which allows us to get the
currently configured vector length using the RDVL instruction via either
a library call or stdout of a process and then uses this to both add
verification of enumerated vector lengths to our existing tests and also
add a new test program which exercises both the prctl() and sysfs
interfaces.

In preparation for the forthcomng support for the Scalable Matrix
Extension (SME) [1] which introduces a new vector length managed via a
very similar hardware interface the helper and new test program are
parameterised with the goal of allowing reuse for SME.

[1] https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/scalable-matrix-extension-armv9-a-architecture

v5:
 - Fix a potentially uninialized variable case.
 - Clarify an error message.
 - Add TODO.
v4:
 - Fix fscanf() format string handling to properly confirm the newline.
 - Pull fclose() out of stdio read helper.
 - Change style of child monitoring loop.
v3:
 - Add BTI landing pads to the asm helper functions.
 - Clean up pipes used to talk to children.
 - Remove another unneeded include.
 - Make functions in the main executable static.
 - Match the newline when parsing vector length from the child.
 - Factor out the fscanf() and fclose() from parsing integers from file
   descriptors.
 - getauxval() returns unsigned long.
v2:
 - Tweak log message on failure in sve-probe-vls.
 - Stylistic changes in vec-syscfg.
 - Flush stdout before forking in vec-syscfg.
 - Use EXIT_FAILURE.
 - Use fdopen() to get child output.
 - Replace a bunch of UNIX API usage with stdio.
 - Add a TODO list.
 - Verify that we're root before testing writes to /proc.

Mark Brown (4):
  kselftest/arm64: Provide a helper binary and "library" for SVE RDVL
  kselftest/arm64: Validate vector lengths are set in sve-probe-vls
  kselftest/arm64: Add tests for SVE vector configuration
  kselftest/arm64: Add a TODO list for floating point tests

 tools/testing/selftests/arm64/fp/.gitignore   |   2 +
 tools/testing/selftests/arm64/fp/Makefile     |  11 +-
 tools/testing/selftests/arm64/fp/TODO         |   4 +
 tools/testing/selftests/arm64/fp/rdvl-sve.c   |  14 +
 tools/testing/selftests/arm64/fp/rdvl.S       |  10 +
 tools/testing/selftests/arm64/fp/rdvl.h       |   8 +
 .../selftests/arm64/fp/sve-probe-vls.c        |   5 +
 tools/testing/selftests/arm64/fp/vec-syscfg.c | 593 ++++++++++++++++++
 8 files changed, 644 insertions(+), 3 deletions(-)
 create mode 100644 tools/testing/selftests/arm64/fp/TODO
 create mode 100644 tools/testing/selftests/arm64/fp/rdvl-sve.c
 create mode 100644 tools/testing/selftests/arm64/fp/rdvl.S
 create mode 100644 tools/testing/selftests/arm64/fp/rdvl.h
 create mode 100644 tools/testing/selftests/arm64/fp/vec-syscfg.c


base-commit: ff1176468d368232b684f75e82563369208bc371
-- 
2.20.1