[PATCH 4.19 120/323] ARM: 9136/1: ARMv7-M uses BE-8, not BE-32

From: Greg Kroah-Hartman
Date: Wed Nov 24 2021 - 08:02:47 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

[ Upstream commit 345dac33f58894a56d17b92a41be10e16585ceff ]

When configuring the kernel for big-endian, we set either BE-8 or BE-32
based on the CPU architecture level. Until linux-4.4, we did not have
any ARMv7-M platform allowing big-endian builds, but now i.MX/Vybrid
is in that category, adn we get a build error because of this:

arch/arm/kernel/module-plts.c: In function 'get_module_plt':
arch/arm/kernel/module-plts.c:60:46: error: implicit declaration of function '__opcode_to_mem_thumb32' [-Werror=implicit-function-declaration]

This comes down to picking the wrong default, ARMv7-M uses BE8
like ARMv7-A does. Changing the default gets the kernel to compile
and presumably works.

https://lore.kernel.org/all/1455804123-2526139-2-git-send-email-arnd@xxxxxxxx/

Tested-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/arm/mm/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index b169e580bf829..9738c1f9737c9 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -751,7 +751,7 @@ config CPU_BIG_ENDIAN
config CPU_ENDIAN_BE8
bool
depends on CPU_BIG_ENDIAN
- default CPU_V6 || CPU_V6K || CPU_V7
+ default CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M
help
Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.

--
2.33.0