question about ARM11MP cpu architecture identification

[saeed bishara]

looks fine to me too.

On Tue, Jan 12, 2010 at 9:55 PM, Nicolas Pitre <nico at fluxnic.net> wrote:
> On Tue, 12 Jan 2010, Russell King - ARM Linux wrote:
>
>> On Tue, Jan 12, 2010 at 05:17:33PM +0000, Russell King - ARM Linux wrote:
>> > On Tue, Jan 12, 2010 at 07:03:35PM +0200, saeed bishara wrote:
>> > > On Tue, Jan 12, 2010 at 6:55 PM, Catalin Marinas
>> > > <catalin.marinas at arm.com> wrote:
>> > > > On Tue, 2010-01-12 at 16:42 +0000, Russell King - ARM Linux wrote:
>> > > >> On Tue, Jan 12, 2010 at 04:26:12PM +0000, Catalin Marinas wrote:
>> > > >> > On Tue, 2010-01-12 at 16:21 +0000, saeed bishara wrote:
>> > > >> > >     The ARM11MP (rev r2p0) cpu architecture is ARMv6, and according to
>> > > >> > > the http://infocenter.arm.com, its Main ID register is 0x410FB024, and
>> > > >> > > the MMFR[3:0] is 3. but it looks to me that the cpu_architecture()
>> > > >> > > will identify it as ARMv7, and if the kernel was configured with
>> > > >> > > CPU_V7 only, then the lookup_processor_type() function also will
>> > > >> > > identify it as ARMv7. Am I missing something here?
>> > > >> >
>> > > >> > cpu_architecture() returns the architecture version of the supported MMU
>> > > >> > which on ARM11MPCore is the same as on ARMv7.
>> > > >> >
>> > > >> > Even if it is possible to configure both v6 and v7 in the same kernel, I
>> > > >> > don't think it is currently possible to successfully run such kernel.
>> > > >>
>> > > >> What makes you think that?  I've been building v6+v7 kernels for Realview
>> > > >> (with a patch to provide the right build options for the ARMv7 arch/arm/mm
>> > > >> files) and ISTR it works fine on my Realview board.
>> > > >
>> > > > I don't remember exactly but it didn't work for me some time ago. I
>> > > > think it failed to build (though I could have worked around this with
>> > > > something like -march=all).
>> > > >
>> > > I think you need the attached patch from Lennert (it was planned to be
>> > > sent later by me)
>> >
>> > Using -Wa,-march= for assembler options is actually a better idea.
>> > I'll update my patch with that (which actually reflects what I did
>> > for Integrator/CP with ARM926 + v6).
>>
>> Ok, here's the combined patch.  Ack?
>
> We need this as well so please consider adding it to your tree.
>
> Acked-by: Nicolas Pitre <nico at marvell.com>
>
>
>>
>>  arch/arm/mm/Makefile |   12 ++++++++++++
>>  1 files changed, 12 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
>> index 827e238..e8d34a8 100644
>> --- a/arch/arm/mm/Makefile
>> +++ b/arch/arm/mm/Makefile
>> @@ -27,6 +27,9 @@ obj-$(CONFIG_CPU_ABRT_EV5TJ)        += abort-ev5tj.o
>>  obj-$(CONFIG_CPU_ABRT_EV6)   += abort-ev6.o
>>  obj-$(CONFIG_CPU_ABRT_EV7)   += abort-ev7.o
>>
>> +AFLAGS_abort-ev6.o   :=-Wa,-march=armv6k
>> +AFLAGS_abort-ev7.o   :=-Wa,-march=armv7-a
>> +
>>  obj-$(CONFIG_CPU_PABRT_LEGACY)       += pabort-legacy.o
>>  obj-$(CONFIG_CPU_PABRT_V6)   += pabort-v6.o
>>  obj-$(CONFIG_CPU_PABRT_V7)   += pabort-v7.o
>> @@ -39,6 +42,9 @@ obj-$(CONFIG_CPU_CACHE_V6)  += cache-v6.o
>>  obj-$(CONFIG_CPU_CACHE_V7)   += cache-v7.o
>>  obj-$(CONFIG_CPU_CACHE_FA)   += cache-fa.o
>>
>> +AFLAGS_cache-v6.o    :=-Wa,-march=armv6
>> +AFLAGS_cache-v7.o    :=-Wa,-march=armv7-a
>> +
>>  obj-$(CONFIG_CPU_COPY_V3)    += copypage-v3.o
>>  obj-$(CONFIG_CPU_COPY_V4WT)  += copypage-v4wt.o
>>  obj-$(CONFIG_CPU_COPY_V4WB)  += copypage-v4wb.o
>> @@ -58,6 +64,9 @@ obj-$(CONFIG_CPU_TLB_V6)    += tlb-v6.o
>>  obj-$(CONFIG_CPU_TLB_V7)     += tlb-v7.o
>>  obj-$(CONFIG_CPU_TLB_FA)     += tlb-fa.o
>>
>> +AFLAGS_tlb-v6.o              :=-Wa,-march=armv6
>> +AFLAGS_tlb-v7.o              :=-Wa,-march=armv7-a
>> +
>>  obj-$(CONFIG_CPU_ARM610)     += proc-arm6_7.o
>>  obj-$(CONFIG_CPU_ARM710)     += proc-arm6_7.o
>>  obj-$(CONFIG_CPU_ARM7TDMI)   += proc-arm7tdmi.o
>> @@ -84,6 +93,9 @@ obj-$(CONFIG_CPU_FEROCEON)  += proc-feroceon.o
>>  obj-$(CONFIG_CPU_V6)         += proc-v6.o
>>  obj-$(CONFIG_CPU_V7)         += proc-v7.o
>>
>> +AFLAGS_proc-v6.o     :=-Wa,-march=armv6
>> +AFLAGS_proc-v7.o     :=-Wa,-march=armv7-a
>> +
>>  obj-$(CONFIG_CACHE_FEROCEON_L2)      += cache-feroceon-l2.o
>>  obj-$(CONFIG_CACHE_L2X0)     += cache-l2x0.o
>>  obj-$(CONFIG_CACHE_XSC3L2)   += cache-xsc3l2.o
>>
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>