Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
On 8/22/14 19:09, Michal Marek wrote: > Dne 13.8.2014 10:03, Geert Uytterhoeven napsal(a): >> CC kbuild >> >> On Wed, Aug 13, 2014 at 12:48 AM, Chen Gang wrote: >>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >>> index c49a775..0510a5d 100644 >>> --- a/arch/arm/Kconfig >>> +++ b/arch/arm/Kconfig >>> @@ -199,6 +199,11 @@ config NEED_DMA_MAP_STATE >>> config ARCH_SUPPORTS_UPROBES >>> def_bool y >>> >>> +config CPU_LITTLE_ENDIAN >>> + depends on !CPU_BIG_ENDIAN >>> + def_bool y >>> + >>> + >>> config ARCH_HAS_DMA_SET_COHERENT_MASK >>> bool >> >> As this is a common symbol, and replicated for all affected architectures, >> I'm wondering if we should have the "config CPU_LITTLE_ENDIAN" in >> common Kconfig code instead, and make the individual architectures do a >> "select CPU_LITTLE_ENDIAN"? > > Yes! > > >> Also we could have "config CPU_BIG_ENDIAN", too, and error out >> if none or both are selected (can Kconfig error out?). > > We can error out in the Makefile, if there is consensus that we should > be doing so. > OK, thanks. I have sent patch v3 for it, and did not check related error in Kconfig files. Please check the related patches (excuse me, I send the patch v3 only according to "scripts/maintainers.pl", maybe not cc to you explicitly). Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
Dne 13.8.2014 10:03, Geert Uytterhoeven napsal(a): > CC kbuild > > On Wed, Aug 13, 2014 at 12:48 AM, Chen Gang wrote: >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >> index c49a775..0510a5d 100644 >> --- a/arch/arm/Kconfig >> +++ b/arch/arm/Kconfig >> @@ -199,6 +199,11 @@ config NEED_DMA_MAP_STATE >> config ARCH_SUPPORTS_UPROBES >> def_bool y >> >> +config CPU_LITTLE_ENDIAN >> + depends on !CPU_BIG_ENDIAN >> + def_bool y >> + >> + >> config ARCH_HAS_DMA_SET_COHERENT_MASK >> bool > > As this is a common symbol, and replicated for all affected architectures, > I'm wondering if we should have the "config CPU_LITTLE_ENDIAN" in > common Kconfig code instead, and make the individual architectures do a > "select CPU_LITTLE_ENDIAN"? Yes! > Also we could have "config CPU_BIG_ENDIAN", too, and error out > if none or both are selected (can Kconfig error out?). We can error out in the Makefile, if there is consensus that we should be doing so. Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
On 8/13/14 16:03, Geert Uytterhoeven wrote: > CC kbuild > > On Wed, Aug 13, 2014 at 12:48 AM, Chen Gang wrote: >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >> index c49a775..0510a5d 100644 >> --- a/arch/arm/Kconfig >> +++ b/arch/arm/Kconfig >> @@ -199,6 +199,11 @@ config NEED_DMA_MAP_STATE >> config ARCH_SUPPORTS_UPROBES >> def_bool y >> >> +config CPU_LITTLE_ENDIAN >> + depends on !CPU_BIG_ENDIAN >> + def_bool y >> + >> + >> config ARCH_HAS_DMA_SET_COHERENT_MASK >> bool > > As this is a common symbol, and replicated for all affected architectures, > I'm wondering if we should have the "config CPU_LITTLE_ENDIAN" in > common Kconfig code instead, and make the individual architectures do a > "select CPU_LITTLE_ENDIAN"? > That sounds a good idea to me. > Also we could have "config CPU_BIG_ENDIAN", too, and error out > if none or both are selected (can Kconfig error out?). > It is a good idea to me, welcome any members ideas, especially Kbuild members' ideas, suggestions or completions. Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
CC kbuild
On Wed, Aug 13, 2014 at 12:48 AM, Chen Gang wrote:
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index c49a775..0510a5d 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -199,6 +199,11 @@ config NEED_DMA_MAP_STATE
> config ARCH_SUPPORTS_UPROBES
> def_bool y
>
> +config CPU_LITTLE_ENDIAN
> + depends on !CPU_BIG_ENDIAN
> + def_bool y
> +
> +
> config ARCH_HAS_DMA_SET_COHERENT_MASK
> bool
As this is a common symbol, and replicated for all affected architectures,
I'm wondering if we should have the "config CPU_LITTLE_ENDIAN" in
common Kconfig code instead, and make the individual architectures do a
"select CPU_LITTLE_ENDIAN"?
Also we could have "config CPU_BIG_ENDIAN", too, and error out
if none or both are selected (can Kconfig error out?).
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
On 8/13/14 14:51, H. Peter Anvin wrote:
> On 08/12/2014 10:32 PM, Chen Gang wrote:
>>
>> Yeah, we need.
>>
>>> The solution you suggest assumes that an arch is either little or big
>>> endian.
>>> But we cannot ignore the hybriads that can do both.
>>>
>>
>> For the architectures which can do both, for me, they are: sh, powerpc,
>> m32r, and mips (may mark CPU_LITTLE_ENDIAN), also are: arm/arm64, and
>> c6x (may mark !CPU_BIG_ENDIAN).
>>
>> For the architectures which only support little endian: x86, and ia64.
>>
>> The left, I assumes they are big endian (no any 'ENDIAN' can be found
>> in their Kconfig files). In my memory, except related with Intel, all
>> are (or support) big endian.
>>
>
> I'm quite certain that is wrong. From memory, for example, I believe
> CRIS is littleendian, and sure enough:
>
> : tazenda 103 ; less arch/cris/include/uapi/asm/byteorder.h
> #ifndef _CRIS_BYTEORDER_H
> #define _CRIS_BYTEORDER_H
>
> #include
>
> #endif
>
OK, what you said sounds reasonable to me. After search "endian" in
"./arch", xtensa also can be support both big endian or little endian.
> As far as I know, endianism is always a compile-time option on Linux, so
> we should be able to relatively easily define the architecture so that
> we either have hardwired littleendian, bigendian, or prompt.
>
Yeah, but that may break building and re-config manually. So it is still
necessary to check little endian or big endian during configuration time
("make *config").
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
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Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
On 08/12/2014 10:32 PM, Chen Gang wrote: > > Yeah, we need. > >> The solution you suggest assumes that an arch is either little or big endian. >> But we cannot ignore the hybriads that can do both. >> > > For the architectures which can do both, for me, they are: sh, powerpc, > m32r, and mips (may mark CPU_LITTLE_ENDIAN), also are: arm/arm64, and > c6x (may mark !CPU_BIG_ENDIAN). > > For the architectures which only support little endian: x86, and ia64. > > The left, I assumes they are big endian (no any 'ENDIAN' can be found > in their Kconfig files). In my memory, except related with Intel, all > are (or support) big endian. > I'm quite certain that is wrong. From memory, for example, I believe CRIS is littleendian, and sure enough: : tazenda 103 ; less arch/cris/include/uapi/asm/byteorder.h #ifndef _CRIS_BYTEORDER_H #define _CRIS_BYTEORDER_H #include #endif As far as I know, endianism is always a compile-time option on Linux, so we should be able to relatively easily define the architecture so that we either have hardwired littleendian, bigendian, or prompt. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
On 8/13/14 13:08, Sam Ravnborg wrote: > On Wed, Aug 13, 2014 at 06:48:35AM +0800, Chen Gang wrote: >> x86 and ia64 are always little endian. And another architectures may be >> little endian: mips, sh, powerpc, and m32r (may mark CPU_LITTLE_ENDIAN >> explicitly); also arm(64) and c6x (which may be !CPU_BIG_ENDIAN). >> >> 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 >> for big endian (assume !CPU_LITTLE_ENDIAN is same as CPU_BIG_ENDIAN). > We need to cover three cases here: > - An arch supports only little endian > - An arch supports only big endian > - An arch may be both little and big endian > Yeah, we need. > The solution you suggest assumes that an arch is either little or big endian. > But we cannot ignore the hybriads that can do both. > For the architectures which can do both, for me, they are: sh, powerpc, m32r, and mips (may mark CPU_LITTLE_ENDIAN), also are: arm/arm64, and c6x (may mark !CPU_BIG_ENDIAN). For the architectures which only support little endian: x86, and ia64. The left, I assumes they are big endian (no any 'ENDIAN' can be found in their Kconfig files). In my memory, except related with Intel, all are (or support) big endian. Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
On Wed, Aug 13, 2014 at 06:48:35AM +0800, Chen Gang wrote: > x86 and ia64 are always little endian. And another architectures may be > little endian: mips, sh, powerpc, and m32r (may mark CPU_LITTLE_ENDIAN > explicitly); also arm(64) and c6x (which may be !CPU_BIG_ENDIAN). > > 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 > for big endian (assume !CPU_LITTLE_ENDIAN is same as CPU_BIG_ENDIAN). We need to cover three cases here: - An arch supports only little endian - An arch supports only big endian - An arch may be both little and big endian The solution you suggest assumes that an arch is either little or big endian. But we cannot ignore the hybriads that can do both. Sam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE_ENDIAN explicitly
x86 and ia64 are always little endian. And another architectures may be little endian: mips, sh, powerpc, and m32r (may mark CPU_LITTLE_ENDIAN explicitly); also arm(64) and c6x (which may be !CPU_BIG_ENDIAN). 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 for big endian (assume !CPU_LITTLE_ENDIAN is same as CPU_BIG_ENDIAN). Signed-off-by: Chen Gang --- arch/arm/Kconfig | 5 + arch/arm64/Kconfig | 4 arch/c6x/Kconfig | 4 arch/ia64/Kconfig | 3 +++ arch/x86/Kconfig | 3 +++ 5 files changed, 19 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c49a775..0510a5d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -199,6 +199,11 @@ config NEED_DMA_MAP_STATE config ARCH_SUPPORTS_UPROBES def_bool y +config CPU_LITTLE_ENDIAN + depends on !CPU_BIG_ENDIAN + def_bool y + + config ARCH_HAS_DMA_SET_COHERENT_MASK bool diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 62b4ae1..290a253 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -129,6 +129,10 @@ config KERNEL_MODE_NEON config FIX_EARLYCON_MEM def_bool y +config CPU_LITTLE_ENDIAN + depends on !CPU_BIG_ENDIAN + def_bool y + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig index 77ea09b..56a8f53 100644 --- a/arch/c6x/Kconfig +++ b/arch/c6x/Kconfig @@ -48,6 +48,10 @@ config C6X_BIG_KERNEL If unsure, say N. +config CPU_LITTLE_ENDIAN + depends on !CPU_BIG_ENDIAN + def_bool y + source "init/Kconfig" # Use the generic interrupt handling code in kernel/irq/ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
