Hi Greg,
On Wed, Jun 26, 2019 at 9:23 AM Greg Ungerer <g...@linux-m68k.org> wrote:
> On 26/6/19 8:29 am, Al Viro wrote:
> > On Thu, Jun 13, 2019 at 09:08:54AM +0200, Christoph Hellwig wrote:
> >> Two branches of the ifdef maze actually have the same content, so merge
> >> them.
> >>
> >> Signed-off-by: Christoph Hellwig <h...@lst.de>
> >> ---
> >> include/linux/flat.h | 6 ++----
> >> 1 file changed, 2 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/include/linux/flat.h b/include/linux/flat.h
> >> index 2b7cda6e9c1b..19c586b74b99 100644
> >> --- a/include/linux/flat.h
> >> +++ b/include/linux/flat.h
> >> @@ -69,15 +69,13 @@ struct flat_hdr {
> >> typedef union {
> >> unsigned long value;
> >> struct {
> >> -# if defined(mc68000) && !defined(CONFIG_COLDFIRE)
> >> +#if defined(__LITTLE_ENDIAN_BITFIELD) || \
> >> + (defined(mc68000) && !defined(CONFIG_COLDFIRE))
> >> signed long offset : 30;
> >> unsigned long type : 2;
> >> # elif defined(__BIG_ENDIAN_BITFIELD)
> >> unsigned long type : 2;
> >> signed long offset : 30;
> >> -# elif defined(__LITTLE_ENDIAN_BITFIELD)
> >> - signed long offset : 30;
> >> - unsigned long type : 2;
> >> # else
> >> # error "Unknown bitfield order for flat files."
> >> # endif
> >> --
> >> 2.20.1
> >>
> >
> > FWIW, I wonder if keeping that type is worth bothering.
> > Something like
> > old_reloc(__be32 reloc)
> > {
> > u32 v = be32_to_cpu(reloc);
> > int offset, type;
> >
> > #if (defined(mc68000) && !defined(CONFIG_COLDFIRE))
> > /* old m68k uses unusual format - type is in lower bits of octet 3 */
> > type = v % 4;
> > offset = (int)v / 4;
> > #else
> > /* everything else (including coldfire) has it in upper bits of octet
> > 0 */
> > type = v >> 30;
> > offset = (int)(v << 2) >> 2; /* or (v & 0x1fffffff) - (v &
> > 0x20000000) * 4 */
> > #endif
> > ...
> >
> > and to hell with bitfields, aliasing unions, etc. Unless I'm misreading
> > the whole thing, that is... Greg?
>
> I think you are right. This is much better.
> The old mc6800 is the odd one out, the rest have it in network order,
> and this makes that much clearer.
Is that correct for Microblaze, which can be big or little endian?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
