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| author | Anshuman Khandual <anshuman.khandual@arm.com> | 2022-11-07 19:47:53 +0530 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-11-09 18:13:18 +0000 |
| commit | a4ee28615c7a1e2925e1fcb4ba0fa1aeee633d78 (patch) | |
| tree | 3c4e5db235c93b63d0eebd8f43a6bd3590e0cd06 | |
| parent | f0c4d9fc9cc9462659728d168387191387e903cc (diff) | |
| download | linux-stable-a4ee28615c7a1e2925e1fcb4ba0fa1aeee633d78.tar.gz | |
arm64/mm: Simplify and document pte_to_phys() for 52 bit addresses
pte_to_phys() assembly definition does multiple bits field transformations
to derive physical address, embedded inside a page table entry. Unlike its
C counter part i.e __pte_to_phys(), pte_to_phys() is not very apparent. It
simplifies these operations via a new macro PTE_ADDR_HIGH_SHIFT indicating
how far the pte encoded higher address bits need to be left shifted. While
here, this also updates __pte_to_phys() and __phys_to_pte_val().
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20221107141753.2938621-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 8 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable-hwdef.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 4 |
3 files changed, 6 insertions, 7 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index e5957a53be39..89038067ef34 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -660,12 +660,10 @@ alternative_endif .endm .macro pte_to_phys, phys, pte -#ifdef CONFIG_ARM64_PA_BITS_52 - ubfiz \phys, \pte, #(48 - 16 - 12), #16 - bfxil \phys, \pte, #16, #32 - lsl \phys, \phys, #16 -#else and \phys, \pte, #PTE_ADDR_MASK +#ifdef CONFIG_ARM64_PA_BITS_52 + orr \phys, \phys, \phys, lsl #PTE_ADDR_HIGH_SHIFT + and \phys, \phys, GENMASK_ULL(PHYS_MASK_SHIFT - 1, PAGE_SHIFT) #endif .endm diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index 5ab8d163198f..f658aafc47df 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -159,6 +159,7 @@ #ifdef CONFIG_ARM64_PA_BITS_52 #define PTE_ADDR_HIGH (_AT(pteval_t, 0xf) << 12) #define PTE_ADDR_MASK (PTE_ADDR_LOW | PTE_ADDR_HIGH) +#define PTE_ADDR_HIGH_SHIFT 36 #else #define PTE_ADDR_MASK PTE_ADDR_LOW #endif diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 71a1af42f0e8..daedd6172227 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -77,11 +77,11 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; static inline phys_addr_t __pte_to_phys(pte_t pte) { return (pte_val(pte) & PTE_ADDR_LOW) | - ((pte_val(pte) & PTE_ADDR_HIGH) << 36); + ((pte_val(pte) & PTE_ADDR_HIGH) << PTE_ADDR_HIGH_SHIFT); } static inline pteval_t __phys_to_pte_val(phys_addr_t phys) { - return (phys | (phys >> 36)) & PTE_ADDR_MASK; + return (phys | (phys >> PTE_ADDR_HIGH_SHIFT)) & PTE_ADDR_MASK; } #else #define __pte_to_phys(pte) (pte_val(pte) & PTE_ADDR_MASK) |