On 21 December 2015 at 13:38, Will Deacon <will.dea...@arm.com> wrote:
> On Fri, Dec 18, 2015 at 08:17:35PM -0800, Andrew Pinski wrote:
>> The problem here is that GCC 6 and above emits .arch now
>> for each function so now the global .arch_extension has
>> no effect. This fixes the problem by putting
>> .arch_extension inside ARM64_LSE_ATOMIC_INSN so
>> it is enabled for each place where LSE is used.
>
> Hmm, this is going to affect arch/arm/ much more heavily than arch/arm64.
> .arch_extension is used for virt, mp and sec over there, and it may be
> tricky to isolate the actual instruction usage (at least, virt looks
> lost in kvm/arm.c).
>
> Why can't gas have an option to accept all instruction encodings that it
> knows about, inspite of any .arch directives?
>
Modern GAS supports things like -march=armv7-a+mp+sec+virt, so it
probably makes sense to pass that on the command line when building
for v7 (or +sec only for v6) if the assembler is found to support it
at build time.
>> Signed-off-by: Andrew Pinski <apin...@cavium.com>
>> ---
>> arch/arm64/include/asm/lse.h | 4 +---
>> 1 files changed, 1 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h
>> index 3de42d6..625601f 100644
>> --- a/arch/arm64/include/asm/lse.h
>> +++ b/arch/arm64/include/asm/lse.h
>> @@ -17,8 +17,6 @@
>>
>> #else /* __ASSEMBLER__ */
>>
>> -__asm__(".arch_extension lse");
>> -
>> /* Move the ll/sc atomics out-of-line */
>> #define __LL_SC_INLINE
>> #define __LL_SC_PREFIX(x) __ll_sc_##x
>> @@ -29,7 +27,7 @@ __asm__(".arch_extension lse");
>>
>> /* In-line patching at runtime */
>> #define ARM64_LSE_ATOMIC_INSN(llsc, lse) \
>> - ALTERNATIVE(llsc, lse, ARM64_HAS_LSE_ATOMICS)
>> + ALTERNATIVE(".arch_extension lse\n" llsc, lse,
>> ARM64_HAS_LSE_ATOMICS)
>>
>> #endif /* __ASSEMBLER__ */
>> #else /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
>> --
>> 1.7.2.5
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-ker...@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-ker...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
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/
