[PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Chen Gang]

Some individual modules want to know the architecture's endian attribute
during config time, or may cause compiling break, one sample is below:
(with allm dconfig under microblaze):

    CC [M]  drivers/isdn/hisax/nj_s.o
  drivers/isdn/hisax/nj_s.c: In function 'setup_netjet_s':
  drivers/isdn/hisax/nj_s.c:265:2: error: #error "not running on big endian machines now"
   #error "not running on big endian machines now"

So add endian attributes for all architectures using (next, will let all
architectures choose their endians during config time).

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 init/Kconfig | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/init/Kconfig b/init/Kconfig
index ac033c3..f301cc8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -23,6 +23,12 @@ config CONSTRUCTORS
 config IRQ_WORK
 	bool
 
+config CPU_LITTLE_ENDIAN
+	bool
+
+config CPU_BIG_ENDIAN
+	bool
+
 config BUILDTIME_EXTABLE_SORT
 	bool
 
-- 
1.7.11.7

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Paul Gortmaker]

[[PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using] On 01/09/2014 (Mon 23:46) Chen Gang wrote:

> Some individual modules want to know the architecture's endian attribute
> during config time, or may cause compiling break, one sample is below:
> (with allm dconfig under microblaze):
> 
>     CC [M]  drivers/isdn/hisax/nj_s.o
>   drivers/isdn/hisax/nj_s.c: In function 'setup_netjet_s':
>   drivers/isdn/hisax/nj_s.c:265:2: error: #error "not running on big endian machines now"
>    #error "not running on big endian machines now"
> 
> So add endian attributes for all architectures using (next, will let all
> architectures choose their endians during config time).
> 
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
> ---
>  init/Kconfig | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/init/Kconfig b/init/Kconfig
> index ac033c3..f301cc8 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -23,6 +23,12 @@ config CONSTRUCTORS
>  config IRQ_WORK
>  	bool
>  
> +config CPU_LITTLE_ENDIAN
> +	bool
> +
> +config CPU_BIG_ENDIAN
> +	bool

Perhaps you should take a cursory look at what already exists in tree
before blindly trying to add more to it?

$ git grep CPU_BIG_ENDIAN | wc -l
88

Paul.
--

> +
>  config BUILDTIME_EXTABLE_SORT
>  	bool
>  
> -- 
> 1.7.11.7

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[H. Peter Anvin]

On 09/01/2014 09:08 AM, Paul Gortmaker wrote:
>>>
>> diff --git a/init/Kconfig b/init/Kconfig
>> index ac033c3..f301cc8 100644
>> --- a/init/Kconfig
>> +++ b/init/Kconfig
>> @@ -23,6 +23,12 @@ config CONSTRUCTORS
>>  config IRQ_WORK
>>  	bool
>>  
>> +config CPU_LITTLE_ENDIAN
>> +	bool
>> +
>> +config CPU_BIG_ENDIAN
>> +	bool
> 
> Perhaps you should take a cursory look at what already exists in tree
> before blindly trying to add more to it?
> 
> $ git grep CPU_BIG_ENDIAN | wc -l
> 88
> 

The whole point of this patchset is to make these already widely-used
options universal across the tree.

	-hpa

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Chen Gang]

On 09/02/2014 01:01 AM, H. Peter Anvin wrote:
> On 09/01/2014 09:08 AM, Paul Gortmaker wrote:
>>>>
>>> diff --git a/init/Kconfig b/init/Kconfig
>>> index ac033c3..f301cc8 100644
>>> --- a/init/Kconfig
>>> +++ b/init/Kconfig
>>> @@ -23,6 +23,12 @@ config CONSTRUCTORS
>>>  config IRQ_WORK
>>>  	bool
>>>  
>>> +config CPU_LITTLE_ENDIAN
>>> +	bool
>>> +
>>> +config CPU_BIG_ENDIAN
>>> +	bool
>>
>> Perhaps you should take a cursory look at what already exists in tree
>> before blindly trying to add more to it?
>>
>> $ git grep CPU_BIG_ENDIAN | wc -l
>> 88
>>
> 
> The whole point of this patchset is to make these already widely-used
> options universal across the tree.
> 

Yeah, maybe the patch comments need be improved (mention about what you
said above) to avoid other members' misunderstanding.

If it is necessary (complete the comments), please let me know (I shall
send patch v2 for it).


Thanks.
-- 
Chen Gang

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

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Paul Gortmaker]

[Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using] On 01/09/2014 (Mon 10:01) H. Peter Anvin wrote:

> On 09/01/2014 09:08 AM, Paul Gortmaker wrote:
> >>>
> >> diff --git a/init/Kconfig b/init/Kconfig
> >> index ac033c3..f301cc8 100644
> >> --- a/init/Kconfig
> >> +++ b/init/Kconfig
> >> @@ -23,6 +23,12 @@ config CONSTRUCTORS
> >>  config IRQ_WORK
> >>  	bool
> >>  
> >> +config CPU_LITTLE_ENDIAN
> >> +	bool
> >> +
> >> +config CPU_BIG_ENDIAN
> >> +	bool
> > 
> > Perhaps you should take a cursory look at what already exists in tree
> > before blindly trying to add more to it?
> > 
> > $ git grep CPU_BIG_ENDIAN | wc -l
> > 88
> > 
> 
> The whole point of this patchset is to make these already widely-used
> options universal across the tree.

OK, but that was not at _all_ what I thought when looking at this...

Instead I saw a well intentioned, but perhaps not fully thought out
attempt at fixing a largely irrelevant randconfig/allmodconfig of a
1990's vintage ISDN driver coming from that x86-only era, built against
an architecture that will never use or support it (microblaze).

In today's world, we'd probably not accept a new ethernet driver or
filesystem if it was incapable of handling both BE and LE (exception
being SoC ethernet physically bound to one specific CPU, of course.)
So the justification given in the commit log for expanding the scope to
better deal with the stuff found in ISDN and the like was questionable.

Secondly, I don't think it is well known that Kbuild will tolerate
multiply defined symbols of the exact same name, and since that isn't
mentioned in the commit log (as documented and/or tested), I envisioned
this breaking powerpc and other arch who already define one (or both)
of these two.  I found multi-define _is_ documented as supported in
Documentation/kbuild but I still wonder how much it is used and how
well it handles things like in powerpc, where one of them (LE?) also
lists a "select ... " line and help text under the bool.

So if we want to do this, I'd suggest a commit log that really gets
to the intended point; something along the lines of:

  --------------

  Currently we have some architectures defining their own bool for
  CPU_LITTLE_ENDIAN and/or CPU_BIG_ENDIAN.  As of 3.17-rc3 we have:

    CPU_BIG_ENDIAN: arc, arm, arm64, c6x, mips, powerpc, sh
    CPU_LITTLE_ENDIAN: m32r, mips, powerpc, sh

  Note that the scope does not cover all arch, which reduces the utility
  value of these items in generic and/or arch independent code, as
  neither may be defined, making tests on their values inconclusive.

  To fix the above, the goal is to make both items present in an arch
  independent Kconfig.  We can do this immediately without having to
  simultaneously touch the existing arch bool definitions because...

  This change was tested on a powerpc LE config since it has help text
  and a select line, and the behaviour of both before and after the
  change was found to be ...

  --------------

Also, having the suggested change Cc'd to linux-arch would be sensible,
I think.  And one might want to make it a series, showing the follow on
arch specific commits you have planned that "select" an endian, since
the maintainers may want evidence it will be carried to completion and
they also may have something additional to say (as in the case of arch/arm
where there is already CPU_ENDIAN_BE8 and CPU_ENDIAN_BE32 Kconfig items).

Paul.
--

> 
> 	-hpa
> 
> 

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Chen Gang]

On 9/2/14 13:17, Paul Gortmaker wrote:
> [Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using] On 01/09/2014 (Mon 10:01) H. Peter Anvin wrote:
> 
>> On 09/01/2014 09:08 AM, Paul Gortmaker wrote:
>>>>>
>>>> diff --git a/init/Kconfig b/init/Kconfig
>>>> index ac033c3..f301cc8 100644
>>>> --- a/init/Kconfig
>>>> +++ b/init/Kconfig
>>>> @@ -23,6 +23,12 @@ config CONSTRUCTORS
>>>>  config IRQ_WORK
>>>>  	bool
>>>>  
>>>> +config CPU_LITTLE_ENDIAN
>>>> +	bool
>>>> +
>>>> +config CPU_BIG_ENDIAN
>>>> +	bool
>>>
>>> Perhaps you should take a cursory look at what already exists in tree
>>> before blindly trying to add more to it?
>>>
>>> $ git grep CPU_BIG_ENDIAN | wc -l
>>> 88
>>>
>>
>> The whole point of this patchset is to make these already widely-used
>> options universal across the tree.
> 
> OK, but that was not at _all_ what I thought when looking at this...
> 
> Instead I saw a well intentioned, but perhaps not fully thought out
> attempt at fixing a largely irrelevant randconfig/allmodconfig of a
> 1990's vintage ISDN driver coming from that x86-only era, built against
> an architecture that will never use or support it (microblaze).
> 
> In today's world, we'd probably not accept a new ethernet driver or
> filesystem if it was incapable of handling both BE and LE (exception
> being SoC ethernet physically bound to one specific CPU, of course.)
> So the justification given in the commit log for expanding the scope to
> better deal with the stuff found in ISDN and the like was questionable.
> 

After a simple search, for crypto, it may be endian sensitive, and for
architectures may be endian sensitive, in config time.

  bash-3.2# find ./ | grep Kconfig | xargs grep depend | grep ENDIAN
  .//arch/arm/mm/Kconfig:	depends on ARCH_SUPPORTS_BIG_ENDIAN
  .//arch/arm/mm/Kconfig:	depends on CPU_BIG_ENDIAN
  .//arch/arm/mm/Kconfig:	depends on CPU_BIG_ENDIAN
  .//arch/arm64/Kconfig:	depends on OF && !CPU_BIG_ENDIAN
  .//arch/mips/Kconfig:	depends on SYS_SUPPORTS_BIG_ENDIAN
  .//arch/mips/Kconfig:	depends on SYS_SUPPORTS_LITTLE_ENDIAN
  .//arch/mips/Kconfig:	depends on SGI_IP22 || SGI_IP28 || (SNI_RM && CPU_LITTLE_ENDIAN)
  .//arch/powerpc/platforms/Kconfig.cputype:	depends on !CPU_LITTLE_ENDIAN
  .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
  .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
  .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
  .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
  .//arch/powerpc/platforms/Kconfig.cputype:	depends on CPU_LITTLE_ENDIAN
  [...]
  .//crypto/Kconfig:	depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
  .//crypto/Kconfig:	depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
  .//drivers/crypto/Kconfig:	depends on PPC64 && IBMVIO && !CPU_LITTLE_ENDIAN
  [...]

It is a simple search, so I am not sure whether have other modules also
need LE or BE.


> Secondly, I don't think it is well known that Kbuild will tolerate
> multiply defined symbols of the exact same name, and since that isn't
> mentioned in the commit log (as documented and/or tested), I envisioned
> this breaking powerpc and other arch who already define one (or both)
> of these two.  I found multi-define _is_ documented as supported in
> Documentation/kbuild but I still wonder how much it is used and how
> well it handles things like in powerpc, where one of them (LE?) also
> lists a "select ... " line and help text under the bool.
> 
> So if we want to do this, I'd suggest a commit log that really gets
> to the intended point; something along the lines of:
> 
>   --------------
> 
>   Currently we have some architectures defining their own bool for
>   CPU_LITTLE_ENDIAN and/or CPU_BIG_ENDIAN.  As of 3.17-rc3 we have:
> 
>     CPU_BIG_ENDIAN: arc, arm, arm64, c6x, mips, powerpc, sh
>     CPU_LITTLE_ENDIAN: m32r, mips, powerpc, sh
> 
>   Note that the scope does not cover all arch, which reduces the utility
>   value of these items in generic and/or arch independent code, as
>   neither may be defined, making tests on their values inconclusive.
> 
>   To fix the above, the goal is to make both items present in an arch
>   independent Kconfig.  We can do this immediately without having to
>   simultaneously touch the existing arch bool definitions because...
> 
>   This change was tested on a powerpc LE config since it has help text
>   and a select line, and the behaviour of both before and after the
>   change was found to be ...
> 
>   --------------
> 
> Also, having the suggested change Cc'd to linux-arch would be sensible,
> I think.  And one might want to make it a series, showing the follow on
> arch specific commits you have planned that "select" an endian, since
> the maintainers may want evidence it will be carried to completion and
> they also may have something additional to say (as in the case of arch/arm
> where there is already CPU_ENDIAN_BE8 and CPU_ENDIAN_BE32 Kconfig items).
> 
> Paul.
> --
> 

OK, thanks, what you said above have valuable information to me.

But could you help check my original mail for it? (may also need check
all related replies in kernel mailing list). After finish checking,
welcome any ideas, suggestions or completions.

Thanks.

-------- Forwarded Message --------
Subject: [PATCH v3] arch: Kconfig: Let all architectures set endian explicitly
Date: Fri, 15 Aug 2014 00:54:53 +0800
From: Chen Gang <gang.chen.5i5j@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>, akpm@linux-foundation.org, rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@synopsys.com, Geert Uytterhoeven <geert@linux-m68k.org>, Jean Delvare <jdelvare@suse.de>, linux@arm.linux.org.uk, catalin.marinas@arm.com, will.deacon@arm.com, hskinnemoen@gmail.com, egtvedt@samfundet.no, realmz6@gmail.com, msalter@redhat.com, a-jacquiot@ti.com, starvik@axis.com, jesper.nilsson@axis.com, dhowells@redhat.com, rkuo@codeaurora.org, tony.luck@intel.com, fenghua.yu@intel.com, takata@linux-m32r.org, james.hogan@imgtec.com, Michal Simek <monstr@monstr.eu>, ralf@linux-mips.org, yasutake.koichi@jp.panasonic.com, jonas@southpole.se, jejb@parisc-linux.org, deller@gmx.de, Benjamin Herrenschmidt <benh@kernel.crashing.org>, paulus@samba.org, mpe@ellerman.id.au, Martin Schwidefsky <schwidefsky@de.ibm.com>, heiko.carstens@de.ibm.com, Liqin Chen <liqin.linux@gmail.com>, Lennox Wu <lennox.wu@gmail.com>, David S. Miller <davem@davemloft.net>, cmetcalf@tiler
a.com, jdike@addtoit.com, Richard Weinberger <richard@nod.at>, gxt@mprc.pku.edu.cn, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, chris@zankel.net, jcmvbkbc@gmail.com
CC: linux390@de.ibm.com, x86@kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>, linux-arm-kernel@lists.infradead.org, adi-buildroot-devel@lists.sourceforge.net, linux-c6x-dev@linux-c6x.org, linux-cris-kernel@axis.com, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org, linux-m68k@lists.linux-m68k.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, linux-am33-list@redhat.com, linux@lists.openrisc.net, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, user-mode-linux-user@lists.sourceforge.net, linux-xtensa@linux-xtensa.org

Normal architectures:

 - Big endian: avr32, frv, m68k, openrisc, parisc, s390, sparc

 - Little endian: alpha, blackfin, cris, hexagon, ia64, metag, mn10300,
                  score, unicore32, x86

 - Choose in config time: arc, arm, arm64, c6x, m32r, mips, powerpc, sh

Special architectures:

 - Deside by compiler: microblaze, tile, xtensa.

 - Deside by building host: um

 - Next, need improve Kbuild to probe endian to deside whether need mark
   __BUILDING_TIME_BIG_ENDIAN__ before real config.

Another improvements:

 - score: use '\t' instead of ' '.

 - s390: sort the select value in alpha order.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 arch/alpha/Kconfig      |  1 +
 arch/arc/Kconfig        |  1 +
 arch/arm/Kconfig        |  1 +
 arch/arm64/Kconfig      |  1 +
 arch/avr32/Kconfig      |  1 +
 arch/blackfin/Kconfig   |  1 +
 arch/c6x/Kconfig        |  1 +
 arch/cris/Kconfig       |  1 +
 arch/frv/Kconfig        |  1 +
 arch/hexagon/Kconfig    |  1 +
 arch/ia64/Kconfig       |  1 +
 arch/m32r/Kconfig       |  1 +
 arch/m68k/Kconfig       |  1 +
 arch/metag/Kconfig      |  1 +
 arch/microblaze/Kconfig |  2 ++
 arch/mips/Kconfig       |  1 +
 arch/mn10300/Kconfig    |  1 +
 arch/openrisc/Kconfig   |  1 +
 arch/parisc/Kconfig     |  1 +
 arch/powerpc/Kconfig    |  1 +
 arch/s390/Kconfig       |  3 ++-
 arch/score/Kconfig      | 21 +++++++++++----------
 arch/sparc/Kconfig      |  1 +
 arch/tile/Kconfig       |  2 ++
 arch/um/Kconfig.common  |  2 ++
 arch/unicore32/Kconfig  |  1 +
 arch/x86/Kconfig        |  1 +
 arch/xtensa/Kconfig     |  2 ++
 init/Kconfig            |  6 ++++++
 29 files changed, 49 insertions(+), 11 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index b7ff9a3..1cb7426 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -27,6 +27,7 @@ config ALPHA
 	select MODULES_USE_ELF_RELA
 	select ODD_RT_SIGACTION
 	select OLD_SIGSUSPEND
+	select CPU_LITTLE_ENDIAN
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 9596b0a..e939abd 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -35,6 +35,7 @@ config ARC
 	select OF_EARLY_FLATTREE
 	select PERF_USE_VMALLOC
 	select HAVE_DEBUG_STACKOVERFLOW
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 
 config TRACE_IRQFLAGS_SUPPORT
 	def_bool y
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 32cbbd5..3a806b3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -12,6 +12,7 @@ config ARM
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select BUILDTIME_EXTABLE_SORT if MMU
 	select CLONE_BACKWARDS
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 	select CPU_PM if (SUSPEND || CPU_IDLE)
 	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
 	select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 62b4ae1..c5a91de 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -17,6 +17,7 @@ config ARM64
 	select BUILDTIME_EXTABLE_SORT
 	select CLONE_BACKWARDS
 	select COMMON_CLK
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 	select CPU_PM if (SUSPEND || CPU_IDLE)
 	select DCACHE_WORD_ACCESS
 	select GENERIC_CLOCKEVENTS
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index b6878eb..fab44ee 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -17,6 +17,7 @@ config AVR32
 	select GENERIC_CLOCKEVENTS
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
+	select CPU_BIG_ENDIAN
 	help
 	  AVR32 is a high-performance 32-bit RISC microprocessor core,
 	  designed for cost-sensitive embedded applications, with particular
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index ed30699..348f16d 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -40,6 +40,7 @@ config BLACKFIN
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
+	select CPU_LITTLE_ENDIAN
 
 config GENERIC_CSUM
 	def_bool y
diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index 77ea09b..7e74d14 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -17,6 +17,7 @@ config C6X
 	select OF_EARLY_FLATTREE
 	select GENERIC_CLOCKEVENTS
 	select MODULES_USE_ELF_RELA
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 
 config MMU
 	def_bool n
diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index 52731e2..405a097 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -52,6 +52,7 @@ config CRIS
 	select CLONE_BACKWARDS2
 	select OLD_SIGSUSPEND
 	select OLD_SIGACTION
+	select CPU_LITTLE_ENDIAN
 
 config HZ
 	int
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 34aa193..aa21ccc 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -14,6 +14,7 @@ config FRV
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
 	select HAVE_DEBUG_STACKOVERFLOW
+	select CPU_BIG_ENDIAN
 
 config ZONE_DMA
 	bool
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 4dc89d1..ee91285 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -28,6 +28,7 @@ config HEXAGON
 	select MODULES_USE_ELF_RELA
 	select GENERIC_CPU_DEVICES
 	select HAVE_DMA_ATTRS
+	select CPU_LITTLE_ENDIAN
 	---help---
 	  Qualcomm Hexagon is a processor architecture designed for high
 	  performance and low power across a wide variety of applications.
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index c84c88b..54f32c7 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -49,6 +49,7 @@ config IA64
 	select MODULES_USE_ELF_RELA
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_AUDITSYSCALL
+	select CPU_LITTLE_ENDIAN
 	default y
 	help
 	  The Itanium Processor Family is Intel's 64-bit successor to
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 9e44bbd..1932483 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -16,6 +16,7 @@ config M32R
 	select ARCH_USES_GETTIMEOFFSET
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
+	select CPU_BIG_ENDIAN if !CPU_LITTLE_ENDIAN
 
 config SBUS
 	bool
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 87b7c75..7a7fe25 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -23,6 +23,7 @@ config M68K
 	select MODULES_USE_ELF_RELA
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
+	select CPU_BIG_ENDIAN
 
 config RWSEM_GENERIC_SPINLOCK
 	bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index 0b389a8..e57c6a0 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -29,6 +29,7 @@ config METAG
 	select OF
 	select OF_EARLY_FLATTREE
 	select SPARSE_IRQ
+	select CPU_LITTLE_ENDIAN
 
 config STACKTRACE_SUPPORT
 	def_bool y
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 40e1c1d..d80ae78 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -7,6 +7,8 @@ config MICROBLAZE
 	select CLKSRC_OF
 	select CLONE_BACKWARDS3
 	select COMMON_CLK
+	select CPU_BIG_ENDIAN if __BUILDING_TIME_BIG_ENDIAN__
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CPU_DEVICES
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 900c7e5..671d822 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -52,6 +52,7 @@ config MIPS
 	select HAVE_CC_STACKPROTECTOR
 	select CPU_PM if CPU_IDLE
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 
 menu "Machine selection"
 
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index a648de1..60fb249 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -13,6 +13,7 @@ config MN10300
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
 	select HAVE_DEBUG_STACKOVERFLOW
+	select CPU_LITTLE_ENDIAN
 
 config AM33_2
 	def_bool n
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 88e8336..4757b7d 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -23,6 +23,7 @@ config OPENRISC
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
 	select OR1K_PIC
+	select CPU_BIG_ENDIAN
 
 config MMU
 	def_bool y
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 6e75e20..dc82137 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -29,6 +29,7 @@ config PARISC
 	select TTY # Needed for pdc_cons.c
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_ARCH_AUDITSYSCALL
+	select CPU_BIG_ENDIAN
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 4bc7b62..644c6d4 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -147,6 +147,7 @@ config PPC
 	select ARCH_USE_CMPXCHG_LOCKREF if PPC64
 	select HAVE_ARCH_AUDITSYSCALL
 	select ARCH_SUPPORTS_ATOMIC_RMW
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 
 config GENERIC_CSUM
 	def_bool CPU_LITTLE_ENDIAN
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 05c78bb..8691c6f 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -62,6 +62,7 @@ config S390
 	def_bool y
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK
 	select ARCH_INLINE_READ_LOCK_BH
@@ -97,6 +98,7 @@ config S390
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select BUILDTIME_EXTABLE_SORT
 	select CLONE_BACKWARDS2
+	select CPU_BIG_ENDIAN
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CPU_DEVICES if !SMP
 	select GENERIC_FIND_FIRST_BIT
@@ -145,7 +147,6 @@ config S390
 	select TTY
 	select VIRT_CPU_ACCOUNTING
 	select VIRT_TO_BUS
-	select ARCH_HAS_SG_CHAIN
 
 config SCHED_OMIT_FRAME_POINTER
 	def_bool y
diff --git a/arch/score/Kconfig b/arch/score/Kconfig
index 4ac8cae..713b290 100644
--- a/arch/score/Kconfig
+++ b/arch/score/Kconfig
@@ -1,19 +1,20 @@
 menu "Machine selection"
 
 config SCORE
-       def_bool y
-       select GENERIC_IRQ_SHOW
-       select GENERIC_IOMAP
-       select GENERIC_ATOMIC64
-       select HAVE_MEMBLOCK
-       select HAVE_MEMBLOCK_NODE_MAP
-       select ARCH_DISCARD_MEMBLOCK
-       select GENERIC_CPU_DEVICES
-       select GENERIC_CLOCKEVENTS
-       select HAVE_MOD_ARCH_SPECIFIC
+	def_bool y
+	select GENERIC_IRQ_SHOW
+	select GENERIC_IOMAP
+	select GENERIC_ATOMIC64
+	select HAVE_MEMBLOCK
+	select HAVE_MEMBLOCK_NODE_MAP
+	select ARCH_DISCARD_MEMBLOCK
+	select GENERIC_CPU_DEVICES
+	select GENERIC_CLOCKEVENTS
+	select HAVE_MOD_ARCH_SPECIFIC
 	select VIRT_TO_BUS
 	select MODULES_USE_ELF_REL
 	select CLONE_BACKWARDS
+	select CPU_LITTLE_ENDIAN
 
 choice
 	prompt "System type"
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index a537816..9de09e6 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -43,6 +43,7 @@ config SPARC
 	select ODD_RT_SIGACTION
 	select OLD_SIGSUSPEND
 	select ARCH_HAS_SG_CHAIN
+	select CPU_BIG_ENDIAN
 
 config SPARC32
 	def_bool !64BIT
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 7fcd492..e042479 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -27,6 +27,8 @@ config TILE
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_DEBUG_STACKOVERFLOW
 	select ARCH_WANT_FRAME_POINTERS
+	select CPU_BIG_ENDIAN if __BUILDING_TIME_BIG_ENDIAN__
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 
 # FIXME: investigate whether we need/want these options.
 #	select HAVE_IOREMAP_PROT
diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common
index 6915d28..f696ec2 100644
--- a/arch/um/Kconfig.common
+++ b/arch/um/Kconfig.common
@@ -8,6 +8,8 @@ config UML
 	select GENERIC_IO
 	select GENERIC_CLOCKEVENTS
 	select TTY # Needed for line.c
+	select CPU_BIG_ENDIAN if __BUILDING_TIME_BIG_ENDIAN__
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 
 config MMU
 	bool
diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index 928237a..02be244 100644
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig
@@ -18,6 +18,7 @@ config UNICORE32
 	select ARCH_WANT_FRAME_POINTERS
 	select GENERIC_IOMAP
 	select MODULES_USE_ELF_REL
+	select CPU_LITTLE_ENDIAN
 	help
 	  UniCore-32 is 32-bit Instruction Set Architecture,
 	  including a series of low-power-consumption RISC chip
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1164b7d..9b83e33 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -136,6 +136,7 @@ config X86
 	select HAVE_ACPI_APEI if ACPI
 	select HAVE_ACPI_APEI_NMI if ACPI
 	select ACPI_LEGACY_TABLES_LOOKUP if ACPI
+	select CPU_LITTLE_ENDIAN
 
 config INSTRUCTION_DECODER
 	def_bool y
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3a617af..a3e8f7e 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -22,6 +22,8 @@ config XTENSA
 	select HAVE_IRQ_TIME_ACCOUNTING
 	select HAVE_PERF_EVENTS
 	select COMMON_CLK
+	select CPU_BIG_ENDIAN if __BUILDING_TIME_BIG_ENDIAN__
+	select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
 	help
 	  Xtensa processors are 32-bit RISC machines designed by Tensilica
 	  primarily for embedded systems.  These processors are both
diff --git a/init/Kconfig b/init/Kconfig
index 9565224..6dd3b20 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -23,6 +23,12 @@ config CONSTRUCTORS
 config IRQ_WORK
 	bool
 
+config CPU_LITTLE_ENDIAN
+	bool
+
+config CPU_BIG_ENDIAN
+	bool
+
 config BUILDTIME_EXTABLE_SORT
 	bool
 
-- 
1.7.11.7

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Chen Gang]

On 09/02/2014 02:13 PM, Chen Gang wrote:
> On 9/2/14 13:17, Paul Gortmaker wrote:
>>
>> OK, but that was not at _all_ what I thought when looking at this...
>>
>> Instead I saw a well intentioned, but perhaps not fully thought out
>> attempt at fixing a largely irrelevant randconfig/allmodconfig of a
>> 1990's vintage ISDN driver coming from that x86-only era, built against
>> an architecture that will never use or support it (microblaze).
>>
>> In today's world, we'd probably not accept a new ethernet driver or
>> filesystem if it was incapable of handling both BE and LE (exception
>> being SoC ethernet physically bound to one specific CPU, of course.)
>> So the justification given in the commit log for expanding the scope to
>> better deal with the stuff found in ISDN and the like was questionable.
>>
> 

I guess, we are mainly focus on: "Is it worthy enough to add *ENDIAN in
init/Kconfig?"

It seems really few modules need depend on LE or BE (although I am still
not quite sure). If it is true, for me, only for architectures, it is
still worthy enough to let all duplicated *ENDIAN to one place.

If it is still worthy, maybe this patch need be improvement (especially,
for its comments), so please help check when you have time, thanks.


Welcome any other members' ideas, suggestions, or completions.

Thanks.

> After a simple search, for crypto, it may be endian sensitive, and for
> architectures may be endian sensitive, in config time.
> 
>   bash-3.2# find ./ | grep Kconfig | xargs grep depend | grep ENDIAN
>   .//arch/arm/mm/Kconfig:	depends on ARCH_SUPPORTS_BIG_ENDIAN
>   .//arch/arm/mm/Kconfig:	depends on CPU_BIG_ENDIAN
>   .//arch/arm/mm/Kconfig:	depends on CPU_BIG_ENDIAN
>   .//arch/arm64/Kconfig:	depends on OF && !CPU_BIG_ENDIAN
>   .//arch/mips/Kconfig:	depends on SYS_SUPPORTS_BIG_ENDIAN
>   .//arch/mips/Kconfig:	depends on SYS_SUPPORTS_LITTLE_ENDIAN
>   .//arch/mips/Kconfig:	depends on SGI_IP22 || SGI_IP28 || (SNI_RM && CPU_LITTLE_ENDIAN)
>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on !CPU_LITTLE_ENDIAN
>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on CPU_LITTLE_ENDIAN
>   [...]
>   .//crypto/Kconfig:	depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
>   .//crypto/Kconfig:	depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
>   .//drivers/crypto/Kconfig:	depends on PPC64 && IBMVIO && !CPU_LITTLE_ENDIAN
>   [...]
> 
> It is a simple search, so I am not sure whether have other modules also
> need LE or BE.
> 

Thanks.
-- 
Chen Gang

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

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Chen Gang]

Hello Maintainers:

Is this patch worthy enough to be applied?

Welcome any ideas, suggestions or completions.

Thanks.

On 09/03/2014 07:47 PM, Chen Gang wrote:
> On 09/02/2014 02:13 PM, Chen Gang wrote:
>> On 9/2/14 13:17, Paul Gortmaker wrote:
>>>
>>> OK, but that was not at _all_ what I thought when looking at this...
>>>
>>> Instead I saw a well intentioned, but perhaps not fully thought out
>>> attempt at fixing a largely irrelevant randconfig/allmodconfig of a
>>> 1990's vintage ISDN driver coming from that x86-only era, built against
>>> an architecture that will never use or support it (microblaze).
>>>
>>> In today's world, we'd probably not accept a new ethernet driver or
>>> filesystem if it was incapable of handling both BE and LE (exception
>>> being SoC ethernet physically bound to one specific CPU, of course.)
>>> So the justification given in the commit log for expanding the scope to
>>> better deal with the stuff found in ISDN and the like was questionable.
>>>
>>
> 
> I guess, we are mainly focus on: "Is it worthy enough to add *ENDIAN in
> init/Kconfig?"
> 
> It seems really few modules need depend on LE or BE (although I am still
> not quite sure). If it is true, for me, only for architectures, it is
> still worthy enough to let all duplicated *ENDIAN to one place.
> 
> If it is still worthy, maybe this patch need be improvement (especially,
> for its comments), so please help check when you have time, thanks.
> 
> 
> Welcome any other members' ideas, suggestions, or completions.
> 
> Thanks.
> 
>> After a simple search, for crypto, it may be endian sensitive, and for
>> architectures may be endian sensitive, in config time.
>>
>>   bash-3.2# find ./ | grep Kconfig | xargs grep depend | grep ENDIAN
>>   .//arch/arm/mm/Kconfig:	depends on ARCH_SUPPORTS_BIG_ENDIAN
>>   .//arch/arm/mm/Kconfig:	depends on CPU_BIG_ENDIAN
>>   .//arch/arm/mm/Kconfig:	depends on CPU_BIG_ENDIAN
>>   .//arch/arm64/Kconfig:	depends on OF && !CPU_BIG_ENDIAN
>>   .//arch/mips/Kconfig:	depends on SYS_SUPPORTS_BIG_ENDIAN
>>   .//arch/mips/Kconfig:	depends on SYS_SUPPORTS_LITTLE_ENDIAN
>>   .//arch/mips/Kconfig:	depends on SGI_IP22 || SGI_IP28 || (SNI_RM && CPU_LITTLE_ENDIAN)
>>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on !CPU_LITTLE_ENDIAN
>>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
>>   .//arch/powerpc/platforms/Kconfig.cputype:	depends on CPU_LITTLE_ENDIAN
>>   [...]
>>   .//crypto/Kconfig:	depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
>>   .//crypto/Kconfig:	depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
>>   .//drivers/crypto/Kconfig:	depends on PPC64 && IBMVIO && !CPU_LITTLE_ENDIAN
>>   [...]
>>
>> It is a simple search, so I am not sure whether have other modules also
>> need LE or BE.
>>
> 
> Thanks.
> 


-- 
Chen Gang

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

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Arnd Bergmann]

On Sunday 14 September 2014, Chen Gang wrote:
> Hello Maintainers:
> 
> Is this patch worthy enough to be applied?
> 
> Welcome any ideas, suggestions or completions.

I find it hard to judge whether it's worth it or not. You gave one example
for a driver that needs this, but what would be your estimate on how
many other drivers have the same problem, either producing a #warning
or misbehaving if neither symbol is set?

Having all architectures consistently report the endianess would be nice,
but we have to weigh the advantages (currently broken code, potential
simplifications) against the regression risk.

	Arnd

Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using

[Chen Gang]

On 09/15/2014 09:55 PM, Arnd Bergmann wrote:
> On Sunday 14 September 2014, Chen Gang wrote:
>> Hello Maintainers:
>>
>> Is this patch worthy enough to be applied?
>>
>> Welcome any ideas, suggestions or completions.
> 
> I find it hard to judge whether it's worth it or not. You gave one example
> for a driver that needs this, but what would be your estimate on how
> many other drivers have the same problem, either producing a #warning
> or misbehaving if neither symbol is set?
> 

For me, it is also hard to judge, so at present, we can assume it is not
worthy enough for other individual modules.

> Having all architectures consistently report the endianess would be nice,
> but we have to weigh the advantages (currently broken code, potential
> simplifications) against the regression risk.
> 

Yeah, so our 'goal' is OK, but we need focus on 'how'.

At present, firstly need modify 'init/Kconfig', and then scan all
architectures one by one, let each related patch pass checking by the
related maintainers (which can avoid the risk).


Thanks.
-- 
Chen Gang

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