From 4c97a0c8fee302fe64feed21e6f7ed25e3e651b8 Mon Sep 17 00:00:00 2001
From: Babu Moger <babu.moger@oracle.com>
Date: Fri, 8 Sep 2017 16:14:22 -0700
Subject: [PATCH] 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>
---
arch/frv/Kconfig | 3 +++
arch/h8300/Kconfig | 3 +++
arch/m68k/Kconfig | 3 +++
arch/openrisc/Kconfig | 3 +++
arch/parisc/Kconfig | 3 +++
arch/sparc/Kconfig | 3 +++
6 files changed, 18 insertions(+)
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index eefd9a4ed15675..1cce8243449e03 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -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
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 6e3d36f37a02f1..3089f7fe2abdb2 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
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 5abb548f0e7075..353d90487c2b9e 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -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
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 1e95920b073774..a0f2e4a323c1d5 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -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
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 13648519bd415e..ba7b7ddc38442d 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -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
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index a4a626199c47e1..0be3828752e5bc 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -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
--
GitLab