Re: [PATCH v5 1/3] xen/mm: Introduce mm-types.h

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 25 Apr 2025, Andrew Cooper wrote:
> The type used for pagetable attributes/permissions is currently unsigned int,
> but needs to become architecture dependent as PPC needs unsigned long.
> 
> Introduce mm-types.h to house pte_attr_t.
> 
> Given the new toolchain baseline, we can use __has_include() now to remove the
> need for boilerplate on most architectures.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
> CC: Jan Beulich <JBeulich@xxxxxxxx>
> CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> CC: Julien Grall <julien@xxxxxxx>
> CC: Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
> CC: Bertrand Marquis <bertrand.marquis@xxxxxxx>
> CC: Michal Orzel <michal.orzel@xxxxxxx>
> CC: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> CC: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>
> 
> __has_include() was one of the justifications for the new toolchain baseline,
> and is included in https://gitlab.com/xen-project/xen/-/issues/201
> ---
>  xen/include/xen/mm-types.h | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>  create mode 100644 xen/include/xen/mm-types.h
> 
> diff --git a/xen/include/xen/mm-types.h b/xen/include/xen/mm-types.h
> new file mode 100644
> index 000000000000..19f692e9aaa4
> --- /dev/null
> +++ b/xen/include/xen/mm-types.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef XEN_MM_TYPES_H
> +#define XEN_MM_TYPES_H
> +
> +/*
> + * Types used to abstract away architecture-specific details in the memory
> + * management code.
> + *
> + * Architectures need only provide their own asm/mm-types.h if they want to
> + * override the defaults given here.
> + */
> +#if __has_include(<asm/mm-types.h>)
> +# include <asm/mm-types.h>
> +#else /* !__has_include(<asm/mm-types.h>) */
> +
> +typedef unsigned int pte_attr_t;
> +
> +#endif /* !__has_include(<asm/mm-types.h>) */
> +#endif /* XEN_MM_TYPES_H */
> -- 
> 2.39.5
>