Re: [PATCH] bswap: Add st24_be_p() to store 24 bits in big-endian order

["Cédric Le Goater" <clg@kaod.org>]

On 6/21/24 9:56 AM, Philippe Mathieu-Daudé wrote:
> Commit 14180d6221 ("bswap: Add the ability to store to an
> unaligned 24 bit field") added st24_le_p() for little
> endianness, add st24_be_p() equivalent for bit one.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
> Some SD card registers are 3 bytes wide stored MSB first.
> ---


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


>   include/qemu/bswap.h | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
> index bd67468e5e..ad22910a5d 100644
> --- a/include/qemu/bswap.h
> +++ b/include/qemu/bswap.h
> @@ -38,12 +38,14 @@ static inline void bswap64s(uint64_t *s)
>   #if HOST_BIG_ENDIAN
>   #define be_bswap(v, size) (v)
>   #define le_bswap(v, size) glue(__builtin_bswap, size)(v)
> +#define be_bswap24(v) (v)
>   #define le_bswap24(v) bswap24(v)
>   #define be_bswaps(v, size)
>   #define le_bswaps(p, size) \
>               do { *p = glue(__builtin_bswap, size)(*p); } while (0)
>   #else
>   #define le_bswap(v, size) (v)
> +#define be_bswap24(v) bswap24(v)
>   #define le_bswap24(v) (v)
>   #define be_bswap(v, size) glue(__builtin_bswap, size)(v)
>   #define le_bswaps(v, size)
> @@ -357,6 +359,11 @@ static inline void stw_be_p(void *ptr, uint16_t v)
>       stw_he_p(ptr, be_bswap(v, 16));
>   }
>   
> +static inline void st24_be_p(void *ptr, uint32_t v)
> +{
> +    st24_he_p(ptr, be_bswap24(v));
> +}
> +
>   static inline void stl_be_p(void *ptr, uint32_t v)
>   {
>       stl_he_p(ptr, be_bswap(v, 32));