Re: [PATCH 02/14] SIWv2: iWARP Protocol headers: iwarp.h

[Bart Van Assche <bvanassche@acm.org>]

On Thu, Jun 16, 2011 at 2:41 PM, Bernard Metzler <bmt@zurich.ibm.com> wrote:
> ---
>  drivers/infiniband/hw/siw/iwarp.h |  324 +++++++++++++++++++++++++++++++++++++
>  1 files changed, 324 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/infiniband/hw/siw/iwarp.h
>
> diff --git a/drivers/infiniband/hw/siw/iwarp.h b/drivers/infiniband/hw/siw/iwarp.h
> [ ... ]
> +struct mpa_rr_params {
> +#if defined(__LITTLE_ENDIAN_BITFIELD)
> +       __be16  res:5,
> +               r:1,
> +               c:1,
> +               m:1,
> +               rev:8;
> +#elif defined(__BIG_ENDIAN_BITFIELD)
> +       __be16  m:1,
> +               c:1,
> +               r:1,
> +               res:5,
> +               rev:8;
> +#else
> +#error "Adjust your <asm/byteorder.h> defines"
> +#endif
> +       __be16  pd_len;
> +};

The above style for declaring endianness specific bitfields in the
kernel is generally frowned upon. The preferred style is to declare a
__be32 or __le32 member variable, to define the bitmasks explicitly,
to use the __constant_cpu_to_be32() conversion function and friends
and to verify the resulting code with sparse (make C=1
CF=-D__CHECK_ENDIAN__ ...).

Bart.