Messages in this thread | | | Subject | Re: [RFC V3 07/13] arm64/mm: Add FEAT_LPA2 specific encoding | From | Anshuman Khandual <> | Date | Wed, 13 Oct 2021 08:25:57 +0530 |
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On 10/12/21 4:11 PM, Suzuki K Poulose wrote: > 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.
Changed the existing FEAT_LPA encodings here to use PAGE_SHIFT just to match the new ones being added for FEAT_LPA2. But reasonable for them to be folded into the previous patch instead.
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