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

[Babu Moger]

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(-)