[PATCH 3/3] efi_loader: avoid duplicate weak invalidate_icache_all()

[Ilias Apalodimas]

On Sun, 16 Jun 2024 at 20:31, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> If multiple weak implementations of a weak function exist, it is unclear
> which one the linker should chose. cmd/cache.c already defines a weak
> invalidate_icache_all().
>
> We don't need a call to invalidate_icache_all() on x86.
> ARM, RISC-V, and Sandbox provide an implementation.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>  lib/efi_loader/efi_image_loader.c | 13 +++++++------
>  lib/efi_loader/efi_runtime.c      |  7 ++++++-
>  2 files changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
> index 60424360328..45dc5b6b244 100644
> --- a/lib/efi_loader/efi_image_loader.c
> +++ b/lib/efi_loader/efi_image_loader.c
> @@ -173,11 +173,6 @@ static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
>         return EFI_SUCCESS;
>  }
>
> -void __weak invalidate_icache_all(void)
> -{
> -       /* If the system doesn't support icache_all flush, cross our fingers */
> -}
> -
>  /**
>   * efi_set_code_and_data_type() - determine the memory types to be used for code
>   *                               and data.
> @@ -986,7 +981,13 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
>         /* Flush cache */
>         flush_cache((ulong)efi_reloc,
>                     ALIGN(virt_size, EFI_CACHELINE_SIZE));
> -       invalidate_icache_all();
> +
> +       /*
> +        * If on x86 a write affects a prefetched instruction,
> +        * the prefetch queue is invalidated.
> +        */
> +       if (!CONFIG_IS_ENABLED(X86))
> +               invalidate_icache_all();
>
>         /* Populate the loaded image interface bits */
>         loaded_image_info->image_base = efi_reloc;
> diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> index 011bcd04836..05369c47b01 100644
> --- a/lib/efi_loader/efi_runtime.c
> +++ b/lib/efi_loader/efi_runtime.c
> @@ -783,7 +783,12 @@ void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
>         lastoff = offset;
>  #endif
>
> -        invalidate_icache_all();
> +       /*
> +        * If on x86 a write affects a prefetched instruction,
> +        * the prefetch queue is invalidated.
> +        */
> +       if (!CONFIG_IS_ENABLED(X86))
> +               invalidate_icache_all();
>  }
>
>  /**
> --
> 2.43.0
>

Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>