Re: [RFC V3 07/13] arm64/mm: Add FEAT_LPA2 specific encoding
From: Anshuman Khandual <hidden>
Date: 2021-10-13 02:56:09
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On 10/12/21 4:11 PM, Suzuki K Poulose wrote:
On 30/09/2021 11:35, Anshuman Khandual wrote:quoted
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 <redacted> --- 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. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel