From: Steve Capper <steve.capper@arm.com>
Date: Wed, 7 Aug 2019 16:55:13 +0100
Subject: arm64: mm: Remove bit-masking optimisations for PAGE_OFFSET and
 VMEMMAP_START
Patch-mainline: v5.4-rc1
Git-commit: 9cb1c5ddd2c432834dd4f40c0170d6b639e8e5c3
References: jsc#SLE-16407

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: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 arch/arm64/include/asm/memory.h |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -299,21 +299,20 @@ static inline void *phys_to_virt(phys_ad
 #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