On Tue, Nov 27, 2018 at 06:08:57PM +0800, Jackie Liu wrote:
> In a way similar to ARM commit 09096f6a0ee2 ("ARM: 7822/1: add workaround
> for ambiguous C99 stdint.h types"), this patch redefines the macros that
> are used in stdint.h so its definitions of uint64_t and int64_t are
> compatible with those of the kernel.
>
> This patch comes from: https://patchwork.kernel.org/patch/3540001/
> Wrote by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
>
> We mark this file as a private file and don't have to override asm/types.h
>
> Signed-off-by: Jackie Liu <liuyun01@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/neon-intrinsics.h | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
> create mode 100644 arch/arm64/include/asm/neon-intrinsics.h
>
> diff --git a/arch/arm64/include/asm/neon-intrinsics.h b/arch/arm64/include/asm/neon-intrinsics.h
> new file mode 100644
> index 0000000..96a3fda
> --- /dev/null
> +++ b/arch/arm64/include/asm/neon-intrinsics.h
> @@ -0,0 +1,28 @@
> +#ifndef _NEON_INTRINSICS_H
> +#define _NEON_INTRINSICS_H
> +
> +#include <asm-generic/int-ll64.h>
> +
> +/*
> + * For Aarch64, there is some ambiguity in the definition of the types below
> + * between the kernel and GCC itself. This is usually not a big deal, but it
> + * causes trouble when including GCC's version of 'stdint.h' (this is the file
> + * that gets included when you #include <stdint.h> on a -ffreestanding build).
> + * As this file also gets included implicitly when including 'arm_neon.h' (the
> + * NEON intrinsics support header), we need the following to work around the
> + * issue if we want to use NEON intrinsics in the kernel.
> + */
> +
> +#ifdef __INT64_TYPE__
> +#undef __INT64_TYPE__
> +#define __INT64_TYPE__ __signed__ long long
Minor query: Out of interest, why __signed__ here, and not signed?
Most similar headers do the same, but I haven't figured out why.
Cheers
---Dave
