On Fri, 12 Feb 2021 08:01:15 -0600 Alex Elder wrote:
> On 2/11/21 8:04 PM, Jakub Kicinski wrote:
> > On Fri, 12 Feb 2021 03:05:23 +0530 Sharath Chandra Vurukala wrote:
> >> +/* MAP CSUM headers */
> >> +struct rmnet_map_v5_csum_header {
> >> + u8 next_hdr:1;
> >> + u8 header_type:7;
> >> + u8 hw_reserved:5;
> >> + u8 priority:1;
> >> + u8 hw_reserved_bit:1;
> >> + u8 csum_valid_required:1;
> >> + __be16 reserved;
> >> +} __aligned(1);
> >
> > Will this work on big endian?
>
> Sort of related to this point...
>
> I'm sure the response to this will be to add two versions
> of the definition, surrounded __LITTLE_ENDIAN_BITFIELD
> and __BIG_ENDIAN_BITFIELD tests.
>
> I really find this non-intuitive, and every time I
> look at it I have to think about it a bit to figure
> out where the bits actually lie in the word.
>
> I know this pattern is used elsewhere in the networking
> code, but that doesn't make it any easier for me to
> understand...
>
> Can we used mask, defined in host byte order, to
> specify the positions of these fields?
>
> I proposed a change at one time that did this and
> this *_ENDIAN_BITFIELD thing was used instead.
>
> I will gladly implement this change (completely
> separate from what's being done here), but thought
> it might be best to see what people think about it
> before doing that work.
Most definitely agree, please convert.
