[Question] Is little endian supported on all the platforms?

[Boqun Feng]

On Mon, Aug 31, 2015 at 02:12:54PM +0200, Cédric Le Goater wrote:
> 
> 
> or like this, to be consistent with the other *_CPU configs in Kconfig.cputype :
> 
> --- a/arch/powerpc/platforms/ps3/Kconfig
> +++ b/arch/powerpc/platforms/ps3/Kconfig
> @@ -1,6 +1,6 @@
>  config PPC_PS3
>         bool "Sony PS3"
> -       depends on PPC64 && PPC_BOOK3S
> +       depends on PPC64 && PPC_BOOK3S && !CPU_LITTLE_ENDIAN
>         select PPC_CELL
>         select USB_OHCI_LITTLE_ENDIAN
>         select USB_OHCI_BIG_ENDIAN_MMIO
>

Hmm.. this works, however I would prefer to CPU_BIG_ENDIAN rather than
!CPU_LITTLE_ENDIAN because CPU_BIG_ENDIAN is more straightforward.

Does this look good?

Regards,
Boqun

-------8<
Subject: [PATCH] powerpc: Kconfig: remove BE-only platforms in LE kernel build

Currently, little endian is only supported on powernv and pseries,
however, Kconfig still allow us to include other platforms in a LE
kernel, this may result in space wasting or even build errors if some
BE-only platforms always assume they are built for a BE kernel. So just
modify the Kconfigs in BE-only platforms to remove them from being built
for a LE kernel.

For 32bit only platforms, nothing needs to be done, because LE depends on
PPC64. For 64bit supported platforms, add CPU_BIG_ENDIAN to dependencies
explicitly [Suggested-by: Cédric Le Goater <clg at fr.ibm.com>].

Signed-off-by: Boqun Feng <boqun.feng at gmail.com>
---
 arch/powerpc/platforms/cell/Kconfig     | 4 ++--
 arch/powerpc/platforms/maple/Kconfig    | 2 +-
 arch/powerpc/platforms/pasemi/Kconfig   | 2 +-
 arch/powerpc/platforms/powermac/Kconfig | 2 +-
 arch/powerpc/platforms/ps3/Kconfig      | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/platforms/cell/Kconfig b/arch/powerpc/platforms/cell/Kconfig
index b0ac177..429fc59 100644
--- a/arch/powerpc/platforms/cell/Kconfig
+++ b/arch/powerpc/platforms/cell/Kconfig
@@ -25,7 +25,7 @@ config PPC_CELL_NATIVE
 
 config PPC_IBM_CELL_BLADE
 	bool "IBM Cell Blade"
-	depends on PPC64 && PPC_BOOK3S
+	depends on PPC64 && PPC_BOOK3S && CPU_BIG_ENDIAN
 	select PPC_CELL_NATIVE
 	select PPC_OF_PLATFORM_PCI
 	select PCI
@@ -35,7 +35,7 @@ config PPC_IBM_CELL_BLADE
 
 config PPC_CELL_QPACE
 	bool "IBM Cell - QPACE"
-	depends on PPC64 && PPC_BOOK3S
+	depends on PPC64 && PPC_BOOK3S && CPU_BIG_ENDIAN
 	select PPC_CELL_COMMON
 
 config AXON_MSI
diff --git a/arch/powerpc/platforms/maple/Kconfig b/arch/powerpc/platforms/maple/Kconfig
index 1ea621a..e359d0d 100644
--- a/arch/powerpc/platforms/maple/Kconfig
+++ b/arch/powerpc/platforms/maple/Kconfig
@@ -1,5 +1,5 @@
 config PPC_MAPLE
-	depends on PPC64 && PPC_BOOK3S
+	depends on PPC64 && PPC_BOOK3S && CPU_BIG_ENDIAN
 	bool "Maple 970FX Evaluation Board"
 	select PCI
 	select MPIC
diff --git a/arch/powerpc/platforms/pasemi/Kconfig b/arch/powerpc/platforms/pasemi/Kconfig
index a2aeb32..00d4b28 100644
--- a/arch/powerpc/platforms/pasemi/Kconfig
+++ b/arch/powerpc/platforms/pasemi/Kconfig
@@ -1,5 +1,5 @@
 config PPC_PASEMI
-	depends on PPC64 && PPC_BOOK3S
+	depends on PPC64 && PPC_BOOK3S && CPU_BIG_ENDIAN
 	bool "PA Semi SoC-based platforms"
 	default n
 	select MPIC
diff --git a/arch/powerpc/platforms/powermac/Kconfig b/arch/powerpc/platforms/powermac/Kconfig
index 607124b..43c6062 100644
--- a/arch/powerpc/platforms/powermac/Kconfig
+++ b/arch/powerpc/platforms/powermac/Kconfig
@@ -1,6 +1,6 @@
 config PPC_PMAC
 	bool "Apple PowerMac based machines"
-	depends on PPC_BOOK3S
+	depends on PPC_BOOK3S && CPU_BIG_ENDIAN
 	select MPIC
 	select PCI
 	select PPC_INDIRECT_PCI if PPC32
diff --git a/arch/powerpc/platforms/ps3/Kconfig b/arch/powerpc/platforms/ps3/Kconfig
index 56f2740..b27f40f 100644
--- a/arch/powerpc/platforms/ps3/Kconfig
+++ b/arch/powerpc/platforms/ps3/Kconfig
@@ -1,6 +1,6 @@
 config PPC_PS3
 	bool "Sony PS3"
-	depends on PPC64 && PPC_BOOK3S
+	depends on PPC64 && PPC_BOOK3S && CPU_BIG_ENDIAN
 	select PPC_CELL
 	select USB_OHCI_LITTLE_ENDIAN
 	select USB_OHCI_BIG_ENDIAN_MMIO