Re: [PATCH v11 06/40] arm64/sme: Provide ABI documentation for SME

[Shuah Khan <skhan@linuxfoundation.org>]

Hi Mark,

On 2/7/22 8:20 AM, Mark Brown wrote:
> Provide ABI documentation for SME similar to that for SVE. Due to the very
> large overlap around streaming SVE mode in both implementation and
> interfaces documentation for streaming mode SVE is added to the SVE
> document rather than the SME one.
> 
> Signed-off-by: Mark Brown <broonie@kernel.org>

A few typos and missing SPDX comments below.
> ---
>   Documentation/arm64/index.rst |   1 +
>   Documentation/arm64/sme.rst   | 432 ++++++++++++++++++++++++++++++++++
>   Documentation/arm64/sve.rst   |  70 +++++-
>   3 files changed, 493 insertions(+), 10 deletions(-)
>   create mode 100644 Documentation/arm64/sme.rst
> 
> diff --git a/Documentation/arm64/index.rst b/Documentation/arm64/index.rst
> index 4f840bac083e..ae21f8118830 100644
> --- a/Documentation/arm64/index.rst
> +++ b/Documentation/arm64/index.rst
> @@ -21,6 +21,7 @@ ARM64 Architecture
>       perf
>       pointer-authentication
>       silicon-errata
> +    sme
>       sve
>       tagged-address-abi
>       tagged-pointers
> diff --git a/Documentation/arm64/sme.rst b/Documentation/arm64/sme.rst
> new file mode 100644
> index 000000000000..15df3157c592
> --- /dev/null
> +++ b/Documentation/arm64/sme.rst
> @@ -0,0 +1,432 @@

Missing SPDX here?

> +===================================================
> +Scalable Matrix Extension support for AArch64 Linux
> +===================================================
> +


> +
> +When returning from a signal handler:
> +
> +* If there is no za_context record in the signal frame, or if the record is
> +  present but contains no register data as desribed in the previous section,

described

> +  then ZA is disabled.
> +

> +	PR_SME_SET_VL_ONEXEC
> +
> +	    Defer the requested vector length change until the next execve()
> +	    performed by this thread.
> +
> +	    The effect is equivalent to implicit exceution of the following

execution

> +	    call immediately after the next execve() (if any) by the thread:
> +

> +
> +[3] Documentation/arm64/cpu-feature-registers.rst
> +
> +[4] ARM IHI0055C
> +    http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055c/IHI0055C_beta_aapcs64.pdf
> +    http://infocenter.arm.com/help/topic/com.arm.doc.subset.swdev.abi/index.html
> +    Procedure Call Standard for the ARM 64-bit Architecture (AArch64)
> diff --git a/Documentation/arm64/sve.rst b/Documentation/arm64/sve.rst
> index 9d9a4de5bc34..93c2c2990584 100644
> --- a/Documentation/arm64/sve.rst
> +++ b/Documentation/arm64/sve.rst
> @@ -7,7 +7,9 @@ Author: Dave Martin <Dave.Martin@arm.com>
>   Date:   4 August 2017
>   

Missing SPDX perhaps?

>   This document outlines briefly the interface provided to userspace by Linux in
> -order to support use of the ARM Scalable Vector Extension (SVE).
> +order to support use of the ARM Scalable Vector Extension (SVE), including
> +interactions with Streaming SVE mode added by the Scalable Matrix Extension
> +(SME).
>   

Looks good otherwise.

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

thanks,
-- Shuah