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arch: define CPU_BIG_ENDIAN for all fixed big endian archs
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Patch series "Define CPU_BIG_ENDIAN or warn for inconsistencies", v3.

While working on enabling queued rwlock on SPARC, found this following
code in include/asm-generic/qrwlock.h which uses CONFIG_CPU_BIG_ENDIAN to
clear a byte.

static inline u8 *__qrwlock_write_byte(struct qrwlock *lock)
 {
	return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN);
 }

Problem is many of the fixed big endian architectures don't define
CPU_BIG_ENDIAN and clears the wrong byte.

Define CPU_BIG_ENDIAN for all the fixed big endian architecture to fix it.

Also found few more references of this config parameter in
drivers/of/base.c
drivers/of/fdt.c
drivers/tty/serial/earlycon.c
drivers/tty/serial/serial_core.c
Be aware that this may cause regressions if someone has worked-around
problems in the above code already. Remove the work-around.

Here is our original discussion
https://lkml.org/lkml/2017/5/24/620

Link: http://lkml.kernel.org/r/1499358861-179979-2-git-send-email-babu.moger@oracle.com
Signed-off-by: Babu Moger <babu.moger@oracle.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Babu Moger authored and Linus Torvalds committed Sep 9, 2017
1 parent 9b130ad commit 4c97a0c
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Showing 6 changed files with 18 additions and 0 deletions.
3 changes: 3 additions & 0 deletions arch/frv/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,9 @@ config FRV
select HAVE_DEBUG_STACKOVERFLOW
select ARCH_NO_COHERENT_DMA_MMAP

config CPU_BIG_ENDIAN
def_bool y

config ZONE_DMA
bool
default y
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3 changes: 3 additions & 0 deletions arch/h8300/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,9 @@ config H8300
select HAVE_ARCH_HASH
select CPU_NO_EFFICIENT_FFS

config CPU_BIG_ENDIAN
def_bool y

config RWSEM_GENERIC_SPINLOCK
def_bool y

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3 changes: 3 additions & 0 deletions arch/m68k/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,9 @@ config M68K
select OLD_SIGSUSPEND3
select OLD_SIGACTION

config CPU_BIG_ENDIAN
def_bool y

config RWSEM_GENERIC_SPINLOCK
bool
default y
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3 changes: 3 additions & 0 deletions arch/openrisc/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,9 @@ config OPENRISC
select CPU_NO_EFFICIENT_FFS if !OPENRISC_HAVE_INST_FF1
select NO_BOOTMEM

config CPU_BIG_ENDIAN
def_bool y

config MMU
def_bool y

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3 changes: 3 additions & 0 deletions arch/parisc/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,9 @@ config PARISC
config CPU_BIG_ENDIAN
def_bool y

config CPU_BIG_ENDIAN
def_bool y

config MMU
def_bool y

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3 changes: 3 additions & 0 deletions arch/sparc/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,9 @@ config ARCH_PROC_KCORE_TEXT
config CPU_BIG_ENDIAN
def_bool y

config CPU_BIG_ENDIAN
def_bool y

config ARCH_ATU
bool
default y if SPARC64
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