Re: [PATCH v3 0/3] Define CPU_BIG_ENDIAN or warn for inconsistencies

[Geert Uytterhoeven]

On Tue, Jun 13, 2017 at 12:09 AM, Babu Moger <babu.moger@xxxxxxxxxx> wrote:
> Found this problem while enabling queued rwlock on SPARC.
> The parameter CONFIG_CPU_BIG_ENDIAN is used to clear the
> specific byte in qrwlock structure. Without this parameter,
> we clear the wrong byte.
> Here is the code in include/asm-generic/qrwlock.h
>
> static inline u8 *__qrwlock_write_byte(struct qrwlock *lock)
>   {
>          return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN);
>   }
>
> Also found few more references of this parameter in
> drivers/of/base.c
> drivers/of/fdt.c
> drivers/tty/serial/earlycon.c
> drivers/tty/serial/serial_core.c
>
> Here is our previous discussion.
> https://lkml.org/lkml/2017/5/24/620
>
> Based on the discussion, it was decided to add CONFIG_CPU_BIG_ENDIAN
> for all the fixed big endian architecture(frv, h8300, m68k, openrisc,
> parisc and sparc). And warn if there are inconsistencies in this definition.
>
> v2 -> v3:
>  Added the choice statement for endianness selection for microblaze.
>  Updated the Makefile for microblaze(Suggested by Arnd Bergmann) to
>  properly compile for the correct format.
>  Updated acks.
>
> v1 -> v2:
>  Updated the commit messages and acks.
>
> Babu Moger (3):
>   arch: Define CPU_BIG_ENDIAN for all fixed big endian archs
>   arch/microblaze: Add choice for endianness and update Makefile
>   include: warn for inconsistent endian config definition
>
>  arch/frv/Kconfig                        |    3 +++
>  arch/h8300/Kconfig                      |    3 +++
>  arch/m68k/Kconfig                       |    3 +++
>  arch/microblaze/Kconfig                 |   16 ++++++++++++++++
>  arch/microblaze/Makefile                |    2 ++
>  arch/openrisc/Kconfig                   |    3 +++
>  arch/parisc/Kconfig                     |    3 +++
>  arch/sparc/Kconfig                      |    3 +++
>  include/linux/byteorder/big_endian.h    |    4 ++++
>  include/linux/byteorder/little_endian.h |    4 ++++
>  10 files changed, 44 insertions(+), 0 deletions(-)

We've just got a new user in c1b0bc2dabfa884d ("usb: typec:
Add support for UCSI interface").
So this series should definitely go in soon.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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