[PATCH v2 0/5] ARM: add module autoloading support for crypto modules

[Ard Biesheuvel]

On 15 February 2017 at 20:07, Russell King - ARM Linux
<linux at armlinux.org.uk> wrote:
> On Wed, Feb 15, 2017 at 08:04:07PM +0000, Ard Biesheuvel wrote:
>> On 15 February 2017 at 20:00, Russell King - ARM Linux
>> <linux at armlinux.org.uk> wrote:
>> > On Wed, Jan 11, 2017 at 05:01:53PM +0000, Ard Biesheuvel wrote:
>> >> This series wires up the crypto modules that use the ARM 32-bit versions of
>> >> the ARMv8 Crypto Extensions to udev autoloading, by exposing the HWCAP2
>> >> feature bits via the CPU modalias. This is very similar to the arm64
>> >> implementation, with the notable exception that ARM has its CPU feature
>> >> definitions split across HWCAP and HWCAP2.
>> >
>> > Note that Aarch64 has:
>> >
>> > MODALIAS=cpu:type:aarch64:feature:,0000,0001,0002,0003,0004,0005,0006,0007
>> >
>> > which looks weird with the first numeric entry starting with a ','.
>> >
>>
>> IIRC this is deliberate, since the udev code matches the feature field
>> for *nnnn*, which is what the module alias exposes.
>
> I noticed, feature:*0000* matches both "feature:0000" and "feature:,0000".
>

Right. It's been a while since I ported that code from x86 to generic,
and I don't remember making many changes to it.

>> Yes, I am aware of that. But there aren't /that/ many optional
>> features that lend themselves for module autoloading.
>
> Yes.  Once we've exhausted the HWCAP2 space, we'll either have to add
> HWCAP3 or finish off using the unused 11 in the HWCAP space.
>

For now, we should be fine. I will respin with the + 32 added.