Commit 9cb1c5dd authored by Steve Capper's avatar Steve Capper Committed by Will Deacon
Browse files

arm64: mm: Remove bit-masking optimisations for PAGE_OFFSET and VMEMMAP_START 



Currently there are assumptions about the alignment of VMEMMAP_START
and PAGE_OFFSET that won't be valid after this series is applied.

These assumptions are in the form of bitwise operators being used
instead of addition and subtraction when calculating addresses.

This patch replaces these bitwise operators with addition/subtraction.

Signed-off-by: default avatarSteve Capper <steve.capper@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent e21a712a

arch/arm64/include/asm/memory.h

+5 −6
Original line number Diff line number Diff line
@@ -299,21 +299,20 @@ static inline void *phys_to_virt(phys_addr_t x) 
#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)

#define _virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)

#else

#define __virt_to_pgoff(kaddr)	(((u64)(kaddr) & ~PAGE_OFFSET) / PAGE_SIZE * sizeof(struct page))

#define __page_to_voff(kaddr)	(((u64)(kaddr) & ~VMEMMAP_START) * PAGE_SIZE / sizeof(struct page))

#define __virt_to_pgoff(kaddr)	(((u64)(kaddr) - PAGE_OFFSET) / PAGE_SIZE * sizeof(struct page))

#define __page_to_voff(kaddr)	(((u64)(kaddr) - VMEMMAP_START) * PAGE_SIZE / sizeof(struct page))



#define page_to_virt(page)	({					\

	unsigned long __addr =						\

		((__page_to_voff(page)) | PAGE_OFFSET);			\

		((__page_to_voff(page)) + PAGE_OFFSET);			\

	const void *__addr_tag =					\

		__tag_set((void *)__addr, page_kasan_tag(page));	\

	((void *)__addr_tag);						\

})



#define virt_to_page(vaddr)	((struct page *)((__virt_to_pgoff(vaddr)) | VMEMMAP_START))

#define virt_to_page(vaddr)	((struct page *)((__virt_to_pgoff(vaddr)) + VMEMMAP_START))



#define _virt_addr_valid(kaddr)	pfn_valid((((u64)(kaddr) & ~PAGE_OFFSET) \

					   + PHYS_OFFSET) >> PAGE_SHIFT)

#define _virt_addr_valid(kaddr)	pfn_valid(__virt_to_phys((u64)(kaddr)) >> PAGE_SHIFT)

#endif

#endif

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