[RFC PATCH 05/10] arm64: mm: avoid __pa translations in early_fixmap_init

[Ard Biesheuvel]

On 23 February 2016 at 18:32, Catalin Marinas <catalin.marinas at arm.com> wrote:
> On Tue, Feb 23, 2016 at 06:27:27PM +0100, Ard Biesheuvel wrote:
>> On 23 February 2016 at 18:26, Catalin Marinas <catalin.marinas at arm.com> wrote:
>> > On Tue, Feb 23, 2016 at 06:16:50PM +0100, Ard Biesheuvel wrote:
>> >> On 23 February 2016 at 18:12, Catalin Marinas <catalin.marinas at arm.com> wrote:
>> >> > On Mon, Feb 22, 2016 at 09:54:27PM +0100, Ard Biesheuvel wrote:
>> >> >> --- a/arch/arm64/mm/mmu.c
>> >> >> +++ b/arch/arm64/mm/mmu.c
>> >> >> @@ -679,7 +679,7 @@ void __init early_fixmap_init(void)
>> >> >>
>> >> >>       pgd = pgd_offset_k(addr);
>> >> >>       if (CONFIG_PGTABLE_LEVELS > 3 &&
>> >> >> -         !(pgd_none(*pgd) || pgd_page_paddr(*pgd) == __pa(bm_pud))) {
>> >> >> +         !(pgd_none(*pgd) || pgd_page_paddr(*pgd) == __pa_symbol(bm_pud))) {
>> >> >>               /*
>> >> >>                * We only end up here if the kernel mapping and the fixmap
>> >> >>                * share the top level pgd entry, which should only happen on
>> >> >
>> >> > Do I miss any patches? The for-next/core branch has a pgd_none(*pgd)
>> >> > check here, so this patch does not apply.
>> >> >
>> >>
>> >> This is actually based on the kaslr branch, not for-next/core
>> >>
>> >> I'm happy to rebase and resend.
>> >
>> > That's fine, no need to resend. I plan to move those as well onto
>> > for-next/core but wanted some more testing first on the initial part.
>> >
>> >> I have added some patches for kasan, kvm and smp as well.
>> >
>> > Patches related to the __pa clean-up? Or something else?
>>
>> No, related to the __pa restriction
>
> OK. I'll wait for a while before merging this series to get more reviews
> and testing. I picked the first patch though (high_memory fix).
>

OK, I'll hold off for now. I have enough stuff in flight as it is.
However, I suppose that you will want to address the performance
concern at some point

If anyone wants to do any benchmarking:
git://git.linaro.org/people/ard.biesheuvel/linux-arm.git arm64-pa-linear-mapping

(updated for kasan, KVM, smp etc)