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authorBabu Moger <babu.moger@oracle.com>2017-09-08 16:14:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-08 18:26:48 -0700
commit4c97a0c8fee302fe64feed21e6f7ed25e3e651b8 (patch)
treec5bc5613b0574d1b904783d38870e3acc58b4d4b /arch/h8300
parent9b130ad5bb8255ee8534d92d67e12b2a4887eacb (diff)
downloadlinux-4c97a0c8fee302fe64feed21e6f7ed25e3e651b8.tar.gz
arch: define CPU_BIG_ENDIAN for all fixed big endian archs
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>
Diffstat (limited to 'arch/h8300')
-rw-r--r--arch/h8300/Kconfig3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 6e3d36f37a02..3089f7fe2abd 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -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