On Tue, Aug 11, 2015 at 04:37:46PM +0100, Suzuki K. Poulose wrote: > On 11/08/15 15:23, Catalin Marinas wrote: > >On Mon, Aug 10, 2015 at 07:48:48PM +0200, Ard Biesheuvel wrote: > >>>On 10/08/15 17:06, Catalin Marinas wrote: > >>>>And to debunk some of the counter arguments: > >>>> > >>>>a) Running out of HWCAP bits - I really doubt this, we can always > >>>> introduce 64 more via a new elf_hwcapX > >> > >>Note that ELF_HWCAP is also wired into ifunc resolution of GNU > >>indirect functions, which looks like a useful feature although it > >>isn't used that widely yet. > > > >I forgot to mention, we also need an HWCAP_CPUID with these patches when > >we expose the MRS interface. The ifunc resolver could use MRS when > >available. But I would still keep adding HWCAP bits for new features, > >even if we risk running out of the 64-bit we have now. > > > > Sure, I will add the HWCAP_CPUID in the next version of the series.
+1 Playing with this, I realise that I get a splat if my userspace code tries to do an MRS for an ID register when this series is absent -- we need an hwcap that we can check first. Cheers ---Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
