On Wed, Oct 23, 2024 at 09:38:32PM +0100, Mark Brown wrote:
> Currently we don't use the irritator signal in our floating point stress
> tests so when we added ZA and ZT stress tests we didn't actually bother
> implementing any actual action in the handlers, we just counted the signal
> deliveries. In preparation for using the irritators let's implement them,
> just trivially SMSTOP and SMSTART to reset all bits in the register to 0.
>
> Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> tools/testing/selftests/arm64/fp/za-test.S | 12 ++++--------
> tools/testing/selftests/arm64/fp/zt-test.S | 12 ++++--------
> 2 files changed, 8 insertions(+), 16 deletions(-)
>
> diff --git a/tools/testing/selftests/arm64/fp/za-test.S b/tools/testing/selftests/arm64/fp/za-test.S
> index 1ee0ec36766d2bef92aff50a002813e76e22963c..f902e6ef9077bfa34fa7f85ce572ce3df4346789 100644
> --- a/tools/testing/selftests/arm64/fp/za-test.S
> +++ b/tools/testing/selftests/arm64/fp/za-test.S
> @@ -148,20 +148,16 @@ function check_za
> b memcmp
> endfunction
>
> -// Any SME register modified here can cause corruption in the main
> -// thread -- but *only* the locations modified here.
> +// Modify the live SME register state, signal return will undo our changes
> function irritator_handler
> // Increment the irritation signal count (x23):
> ldr x0, [x2, #ucontext_regs + 8 * 23]
> add x0, x0, #1
> str x0, [x2, #ucontext_regs + 8 * 23]
>
> - // Corrupt some random ZA data
> -#if 0
> - movi v0.8b, #1
> - movi v9.16b, #2
> - movi v31.8b, #3
> -#endif
> + // This will reset ZA to all bits 0
> + smstop
> + smstart
>
> ret
> endfunction
> diff --git a/tools/testing/selftests/arm64/fp/zt-test.S b/tools/testing/selftests/arm64/fp/zt-test.S
> index ade9c98abcdafc2755ef4796670566d99e919e5c..c96cb7c2ad4b406c54099fe3f73917259bd947e4 100644
> --- a/tools/testing/selftests/arm64/fp/zt-test.S
> +++ b/tools/testing/selftests/arm64/fp/zt-test.S
> @@ -117,20 +117,16 @@ function check_zt
> b memcmp
> endfunction
>
> -// Any SME register modified here can cause corruption in the main
> -// thread -- but *only* the locations modified here.
> +// Modify the live SME register state, signal return will undo our changes
> function irritator_handler
> // Increment the irritation signal count (x23):
> ldr x0, [x2, #ucontext_regs + 8 * 23]
> add x0, x0, #1
> str x0, [x2, #ucontext_regs + 8 * 23]
>
> - // Corrupt some random ZT data
> -#if 0
> - movi v0.8b, #1
> - movi v9.16b, #2
> - movi v31.8b, #3
> -#endif
> + // This will reset ZT to all bits 0
> + smstop
> + smstart
>
> ret
> endfunction
>
> --
> 2.39.2
>