[PATCH] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly

[PATCH] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly

[Chen Gang]

x86, ia64, and arm(64) are little endian, and also another architectures
may be little endian (mips, sh, powerpc, and m32r) which already marked
CPU_LITTLE_ENDIAN explicitly.

Some drivers (e.g. some of "drivers/isdn/hisax") may only support little
endian (CPU_LITTLE_ENDIAN), and some drivers may only support big endian
(!CPU_LITTLE_ENDIAN).

So export all little endian architectures within kernel wide, so can let
Kconfig easier for the modules which only support little endian or only
big endian.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 arch/arm/Kconfig   | 3 +++
 arch/arm64/Kconfig | 3 +++
 arch/ia64/Kconfig  | 3 +++
 arch/x86/Kconfig   | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c49a775..bfc2c65 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -199,6 +199,9 @@ config NEED_DMA_MAP_STATE
 config ARCH_SUPPORTS_UPROBES
 	def_bool y
 
+config CPU_LITTLE_ENDIAN
+	def_bool y
+
 config ARCH_HAS_DMA_SET_COHERENT_MASK
 	bool
 
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 62b4ae1..69b893e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -129,6 +129,9 @@ config KERNEL_MODE_NEON
 config FIX_EARLYCON_MEM
 	def_bool y
 
+config CPU_LITTLE_ENDIAN
+	def_bool y
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 64aefb7..fa12d34 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -133,6 +133,9 @@ config AUDIT_ARCH
 	bool
 	default y
 
+config CPU_LITTLE_ENDIAN
+	def_bool y
+
 menuconfig PARAVIRT_GUEST
 	bool "Paravirtualized guest support"
 	depends on BROKEN
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 541e7cc..a1b3568 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -270,6 +270,9 @@ config ARCH_SUPPORTS_UPROBES
 config FIX_EARLYCON_MEM
 	def_bool y
 
+config CPU_LITTLE_ENDIAN
+	def_bool y
+
 source "init/Kconfig"
 source "kernel/Kconfig.freezer"
 
-- 
1.7.11.7

[PATCH] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly

[Russell King - ARM Linux]

On Tue, Aug 12, 2014 at 05:18:44AM +0800, Chen Gang wrote:
> x86, ia64, and arm(64) are little endian, and also another architectures
> may be little endian (mips, sh, powerpc, and m32r) which already marked
> CPU_LITTLE_ENDIAN explicitly.

This is incorrect.  ARM can be either endian.

arch/arm/mm/Kconfig:

config CPU_BIG_ENDIAN
        bool "Build big-endian kernel"
        depends on ARCH_SUPPORTS_BIG_ENDIAN
        help
          Say Y if you plan on running a kernel in big-endian mode.
          Note that your board must be properly built and your board
          port must properly enable any big-endian related features
          of your chipset/board/processor.

-- 
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[PATCH] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly

[Chen Gang]

On 8/12/14 6:53, Russell King - ARM Linux wrote:
> On Tue, Aug 12, 2014 at 05:18:44AM +0800, Chen Gang wrote:
>> x86, ia64, and arm(64) are little endian, and also another architectures
>> may be little endian (mips, sh, powerpc, and m32r) which already marked
>> CPU_LITTLE_ENDIAN explicitly.
> 
> This is incorrect.  ARM can be either endian.
> 
> arch/arm/mm/Kconfig:
> 
> config CPU_BIG_ENDIAN
>         bool "Build big-endian kernel"
>         depends on ARCH_SUPPORTS_BIG_ENDIAN
>         help
>           Say Y if you plan on running a kernel in big-endian mode.
>           Note that your board must be properly built and your board
>           port must properly enable any big-endian related features
>           of your chipset/board/processor.
> 

OK, thanks, I shall check all CPU_BIG_ENDIAN and send patch v2 for it.

And still welcome another ideas, suggestions or completions, especially
for another architectures.


Thanks.
-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed