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: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index fb04f10a78ab35c462e251d0bacce3a05da9be32..98fda92a26127579529ba6b90503a7915528bb84 100644 (file)
--- 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_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