[PATCH 0/4] arm64: advertise availability of CRC and crypto instructions

Ard Biesheuvel ard.biesheuvel at linaro.org
Wed Dec 18 04:50:38 EST 2013


On 17 December 2013 13:25, Catalin Marinas <catalin.marinas at arm.com> wrote:
> On Mon, Dec 16, 2013 at 09:04:34PM +0000, Ard Biesheuvel wrote:
>> This series is an expansion of the patch posted by Steve Capper about 6 weeks
>> ago that allocates hwcaps bits for CRC and Crypto Extensions instructions so
>> userland can discover whether the current CPU has any of those capabilities.
>>
>> Patch #1 is a cleanup patch for read_cpuid(), which allowed me to skip adding
>> yet another #define to asm/cputype.h (for ID_ISAR5_EL1)
>>
>> Patch #2 is Steve's original patch, but slightly tweaked because hwcaps bit 2
>> has been allocated for something else in the mean time.
>>
>> Patch #3 allocates the capability bits in the arch/arm tree. This is necessary
>> because 32-bit ARM binaries can execute both under ARM and under arm64 kernels,
>> so there should be agreement about the meaning of feature bits, even if those
>> features don't actually exist on systems covered by the arch/arm tree.
>>
>> @Russell: if this looks ok to you, could you please indicate whether you prefer
>> to take this patch separately, or ack it and let it be merged as part of the
>> series.
>>
>> Patch #4 advertises the CRC and Crypto Extensions to 32-bit binaries running
>> under an arm64 kernel.
>
> The series look fine to me. I'm happy to take all the patches if Russell
> Acks the arm one (or it can send it via the patch system).
>

Hello Russell,

Care to share your take on this? I imagine new hwcaps bits take a
while to percolate and make their way into a stable glibc, so I would
like to have these changes in sooner rather than later, and 3.14 seems
feasible.

Regards,
Ard.



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