Messages in this thread | | | Subject | Re: [RFC V3 07/13] arm64/mm: Add FEAT_LPA2 specific encoding | From | Suzuki K Poulose <> | Date | Tue, 12 Oct 2021 11:41:47 +0100 |
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On 30/09/2021 11:35, Anshuman Khandual wrote: > FEAT_LPA2 requires different PTE representation formats for both 4K and 16K > page size config. This adds FEAT_LPA2 specific new PTE encodings as per ARM > ARM (0487G.A) which updates [pte|phys]_to_[phys|pte](). The updated helpers > would be used when FEAT_LPA2 gets enabled via CONFIG_ARM64_PA_BITS_52 on 4K > and 16K page size. Although TTBR encoding and phys_to_ttbr() helper remains > the same as FEAT_LPA for FEAT_LPA2 as well. It updates 'phys_to_pte' helper > to accept a temporary variable and changes impacted call sites. > > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > --- > arch/arm64/include/asm/assembler.h | 14 +++++++++++--- > arch/arm64/include/asm/pgtable-hwdef.h | 4 ++++ > arch/arm64/include/asm/pgtable.h | 4 ++++ > 3 files changed, 19 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h > index 3fbe04a..c1543067 100644 > --- a/arch/arm64/include/asm/assembler.h > +++ b/arch/arm64/include/asm/assembler.h > @@ -628,6 +628,10 @@ alternative_endif > */ > orr \pte, \phys, \phys, lsr #36 > and \pte, \pte, #PTE_ADDR_MASK > +#elif defined(CONFIG_ARM64_PA_BITS_52_LPA2) > + orr \pte, \phys, \phys, lsr #42 > + and \pte, \pte, #PTE_ADDR_MASK | GENMASK(PAGE_SHIFT - 1, 10) > + and \pte, \pte, #~GENMASK(PAGE_SHIFT - 1, 10) > #else /* !CONFIG_ARM64_PA_BITS_52_LPA */ > mov \pte, \phys > #endif /* CONFIG_ARM64_PA_BITS_52_LPA */ > @@ -635,9 +639,13 @@ alternative_endif > > .macro pte_to_phys, phys, pte > #ifdef CONFIG_ARM64_PA_BITS_52_LPA > - ubfiz \phys, \pte, #(48 - 16 - 12), #16 > - bfxil \phys, \pte, #16, #32 > - lsl \phys, \phys, #16 > + ubfiz \phys, \pte, #(48 - PAGE_SHIFT - 12), #16 > + bfxil \phys, \pte, #PAGE_SHIFT, #(48 - PAGE_SHIFT)
nit: This looks like an unrelated change and is better suited for the previous patch.
Suzuki
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