Re: [PATCH v12 04/10] set_memory: allow querying whether set_direct_map_*() is actually enabled

David Hildenbrand
2020-11-25T11:23:13Z

> #include <asm-generic/cacheflush.h>
>
> #endif /* __ASM_CACHEFLUSH_H */
> diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
> new file mode 100644
> index 000000000000..ecb6b0f449ab
> --- /dev/null
> +++ b/arch/arm64/include/asm/set_memory.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef _ASM_ARM64_SET_MEMORY_H
> +#define _ASM_ARM64_SET_MEMORY_H
> +
> +#include <asm-generic/set_memory.h>
> +
> +bool can_set_direct_map(void);
> +#define can_set_direct_map can_set_direct_map

Well, that looks weird.
[...]

> }
> +#else /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
> +/*
> + * Some architectures, e.g. ARM64 can disable direct map modifications at
> + * boot time. Let them overrive this query.
> + */
> +#ifndef can_set_direct_map
> +static inline bool can_set_direct_map(void)
> +{
> + return true;
> +}

I think we prefer __weak functions for something like that, avoids the
ifdefery.

Apart from that, LGTM.

--
Thanks,

David / dhildenb