kselftest/arm64: Don't probe the current VL for unsupported vector types

The vec-syscfg selftest verifies that setting the VL of the currently
tested vector type does not disrupt the VL of the other vector type. To do
this it records the current vector length for each type but neglects to
guard this with a check for that vector type actually being supported. Add
one, using a helper function which we also update all the other instances
of this pattern.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20231218-kselftest-arm64-vec-syscfg-rdvl-v1-1-0ac22d47e81f@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: Validate that changing one VL type does not affect another

On a system with both SVE and SME when we change one of the VLs this should
not result in a change in the other VL. Add a check that this is in fact
the case to vec-syscfg.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230720-arm64-fix-sve-sme-vl-change-v2-3-8eea06b82d57@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: Add a test case for SVE VL changes with SME active

We just fixed an issue where changing the SVE VL while SME was active could
result in us attempting to save the streaming mode SVE vectors without any
backing storage. Add a test case which provokes that issue, ideally we
should also verify that the contents of ZA are unaffected by any of what we
did.

Note that since we need to keep streaming mode enabled we can't use any
syscalls to trigger the issue, we have to sit in a loop in usersapce and
hope to be preempted. The chosen numbers trigger with defconfig on all the
virtual platforms for me, this won't be 100% on all systems but avoid an
overcomplicated test implementation.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230720-arm64-fix-sve-sme-vl-change-v2-2-8eea06b82d57@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: Extend vector configuration API tests to cover SME

Provide RDVL helpers for SME and extend the main vector configuration tests
to cover SME.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-32-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

selftests/arm64: remove ARRAY_SIZE define from vec-syscfg.c

ARRAY_SIZE is defined in several selftests. Remove definitions from
individual test files and include header file for the define instead.
ARRAY_SIZE define is added in a separate patch to prepare for this
change.

Remove ARRAY_SIZE from vec-syscfg.c and pickup the one defined in
kselftest.h.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests: arm64: Verify that all possible vector lengths are handled

As part of the enumeration interface for setting vector lengths it is valid
to set vector lengths not supported in the system, these will be rounded to
a supported vector length and returned from the prctl(). Add a test which
exercises this for every valid vector length and makes sure that the return
value is as expected and that this is reflected in the actual system state.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20210929151925.9601-5-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

selftests: arm64: Fix and enable test for setting current VL in vec-syscfg

We had some test code for verifying that we can write the current VL via
the prctl() interface but the condition for the test was inverted which
wasn't noticed as it was never actually hooked up to the array of tests
we execute. Fix this.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210929151925.9601-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

selftests: arm64: Remove bogus error check on writing to files

Due to some refactoring with the error handling we ended up mangling things
so we never actually set ret and therefore shouldn't be checking it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210929151925.9601-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

selftests: arm64: Fix printf() format mismatch in vec-syscfg

The format for this error message calls for the plain text version of the
error but we weren't supply it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210929151925.9601-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: Add tests for SVE vector configuration

We provide interfaces for configuring the SVE vector length seen by
processes using prctl and also via /proc for configuring the default
values. Provide tests that exercise all these interfaces and verify that
they take effect as expected, though at present no test fully enumerates
all the possible vector lengths.

A subset of this is already tested via sve-probe-vls but the /proc
interfaces are not currently covered at all.

In preparation for the forthcoming support for SME, the Scalable Matrix
Extension, which has separately but similarly configured vector lengths
which we expect to offer similar userspace interfaces for, all the actual
files and prctls used are parameterised and we don't validate that the
architectural minimum vector length is the minimum we see.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20210803140450.46624-4-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>